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FIELD OF THE INVENTION
The present invention relates to a gas sensor, and more particularly, to a sensing apparatus capable of detecting and monitoring at least a gas by the use of reference optical paths and sensing optical paths constructed from a planar lightwave circuit of the sensing apparatus.
BACKGROUND OF THE INVENTION
The quantitative and qualitative analysis of gases and their mixtures has been found to be vastly applied in the fields of global environment monitoring, household safety inspecting, greenhouse environmental control, chemical concentration control, and certain applications relating to aerospace industry, etc. Nowadays, it is common to use gas sensors for performing the quantitative and qualitative analysis of gases and their mixtures, since not only the cost of monitoring the gases and their mixtures and the testing cycles required to be performed in the monitoring can be reduced, but also a real-time monitoring of the gases and their mixtures can be achieved thereby. However, cross sensitivity problem is common to those currently available gas sensors, such as semiconductor oxide gas sensors, metal oxide gas sensors, electrochemical gas sensors and solid electrolyte gas sensors, which can cause the reliability and repeatability of a monitoring result performed by such gas sensor to be adversely affected, i.e. the aforesaid gas sensors will fail to measure the individual concentration of each target gases of the monitoring accurately. Although, a gas sensor consists of an array of sensors sensitive to different gases can be used for detecting and measuring a plurality of gases, the cross sensitivity problem still can not be eliminated. For solving the foregoing cross sensitivity problem, the ability of certain gases to absorb infrared radiation has been successfully utilized in developing optical instruments for gas sensing, that is, gases can be selectively detected by the utilization of an infrared sensor via their specific absorption in the infrared spectral range. Despite their functional superiority, the optical gas sensors were not initially popular due to their structural complexity and high manufacturing cost, especially as the size of the optical gas sensor is increasing with the increasing of the amount of optical parts and relating elements of the optical gas sensor needed for detecting and measuring a plurality of gases. Therefore, the optical gas sensor currently available can only be used to detect and measure a gas of the specific infrared spectral range of the gas sensor, that the optical gas sensor can not be adaptively controlled for detecting and measuring various harmful gases coexisted in a same environment.
Please refer to FIG. 1 , which is a schematic illustration of a conventional optical gas sensor used for detecting a specific gas. The optical gas sensor 1 of FIG. 1 is comprised of an infrared radiation source 10 , a reference light source 11 , a chamber 12 , a narrow-band optical filter 13 and a photodiode 14 , wherein the reference light source 11 is disposed in the chamber 12 intermediate to the first and second ends of the chamber 12 , that is, at a distance from the photodiode 14 less than the distance between infrared radiation source 10 and photodiode 14 , and the narrow band optical filter 13 selected for a specific wavelength with respect to a gas to be sensed is mounted between the reference light source 11 and the photodiode 14 . As the infrared radiation source 10 is emitting light of a defined wavelength range to be transmitted and reflected in the chamber 12 , the gas to be sensed in the chamber 12 will absorb the emitted light while enabling the absorbed light of the specific wavelength to pass through the narrow band optical filter 13 to be received by the photodiode 14 . Since the light of the specific wavelength emitted by the reference light source 11 is received by the photodiode 14 without having to travel across the chamber 12 filled of gas to be sensed and thus it is not subject to the absorption of the gas to be sensed, the gas to be sensed can be detected and the concentration of the same can be measured by comparing of the intensity of the light emitted form the reference light source 11 , which is used as a reference value or initial value, with that of the light emitted from the infrared radiation source 10 after passing through the chamber 12 . However, the use of the reference light source in this basic optical gas sensor configuration is to compensate for changes and deterioration of optical components with time and temperature. In practice, the reference light source is added to the sensor to correct for these potential problems.
There are many optical gas sensors currently available, such as those disclosed in U.S. Pat. No. 6,067,840, U.S. Pat. No. 6,469,303, U.S. Pat. No. 6,392,234, U.S. Pat. No. 5,610,400, and U.S. Pat. No. 5,550,375. It is noted that those shown in U.S. Pat. No. 6,067,840, U.S. Pat. No. 6,469,303, U.S. Pat. No. 6,392,234, U.S. Pat. No. 5,610,400, and U.S. Pat. No. 5,550,375 are only suitable for detecting a specific gas while the reference light source for emitting reference light and the infrared radiation source for emitting testing light used in the device shown in U.S. Pat. No. 6,067,840 are two different light sources.
From the above description, there are four major shortcomings can be summed up as following:
(1) By having reference light and testing light to be emitted from two different light sources as those used in prior-art sensors, it is possible that one might not be able to distinct the initial value, being obtained from the reference light representing no target gas sensed, from a response value, being obtained from the testing light representing the existence of the target gas, since the two light sources might begin to deteriorate at different times. Therefore, it is preferred to have the reference light and the testing light to be emitted from a same light source so that the time of deterioration of the two is identical and thus the distinction between the initial value and the response value is ease to identify. (2) It is known that the reflection index of a material/atmosphere is varying along the change of ambient temperature, pressure or the properties of the material, and the change of reflection index will consequently cause the corresponding optical path to change. Hence, since the length of the optical path of the reference light is different from that of the testing light as those used in prior-art sensors while the initial value is subject to the influence of ambient temperature, pressure and the properties of the material, the accuracy and long-term stability of the gas sensor are reduced. (3) The prior-art gas sensors can not be adapted for multi-gas testing. (4) The structure of the prior-art gas sensor can not be flattened.
Therefore, it is in great need to have an apparatus for sensing plural gases that is capable of overcoming the foregoing problems.
SUMMARY OF THE INVENTION
The primary object of the invention is to provide an apparatus for sensing plural gases, which is free from the cross sensitivity problem while it is being used to sense plural gases, and is free from the influences of ambient temperature change, ambient pressure change, wave-guide material property change and the deterioration of light sources so as to increase the accuracy and long-term stability of the aforesaid apparatus, and is a flat gas sensor by the adoption of planar lightwave circuit.
To achieve the above objects, the present invention provides an apparatus for sensing plural gases, which comprises a photogenerator, a planar light wave circuit, and at least a photodetector. The photogenerator is utilized for emitting a signal light. The planar lightwave circuit, having a sensing pathway and a reference pathway, is coupled to the photogenerator by an input port thereof for enabling the same to receive the signal light and thus generate a sensing signal and a reference signal in respective. The sensing pathway and the reference pathway respectively have at least an optic gap and at least an output port. The at least one detector is disposed at one of the output ports of the reference pathway or the output ports of the sensing pathway for converting the sensing/reference signal into an electric signal.
Preferably, the photogenerator is one device selected from the group consisting of an edge-emitting laser diode, a surface-emitting laser diode, and a light emitting diode.
Preferably, the interval of the optic gap formed in the sensing pathway is the same as that in the reference pathway, and the length of the sensing pathway is the same as that of the reference pathway.
Preferably, each optic gap of the reference pathway is sealed by an isolating element.
Preferably, there can be a filter being disposed between each photodetector and the output port corresponding thereto.
Moreover, the apparatus for sensing plural gases further comprises a substrate for carrying the photogenerator, the planar lightwave circuit and the photodetectors, wherein the planar lightwave circuit is formed directly on the surface of the substrate, and is made of a material selected from the group consisting of a semiconductor material, a polymer, and a metal.
Preferably, the apparatus for sensing plural gases further comprises a separation film for isolating dust and dirt while allowing target gases to pass through.
Preferably, the apparatus for sensing plural gases further comprises a control circuit, coupled respectively to the photogenerator and the photodetectors.
In a preferred embodiment of the invention, the present invention provides an apparatus for sensing plural gases, which comprises a plurality of photogenerators, a plurality of planar light wave circuits, and a plurality of photodetectors. Each photogenerators is capable of emitting a signal light. Each planar light wave circuit has a sensing pathway and a reference pathway and is coupled to one of the photogenerators by an input port thereof for enabling the same to receive the signal light and thus generate a sensing signal and a reference signal, respectively. The sensing pathway and the reference pathway respectively have at least an optic gap and at least an output port. Each photodetector is disposed at one of the output ports of the reference pathway or the output ports of the sensing pathway for converting the corresponding sensing/reference signal into an electric signal.
Preferably, the two lights emitted from any two neighboring photogenerators of the plural photogenerators can be specified to a condition selected from the group consisting of: the condition of the same wavelength and the condition of different wavelengths.
Preferably, the apparatus for sensing plural gases further comprises at least an intermittent photogenerator, each being disposed between any of the two neighboring photogenerators; wherein a planar lightwave circuit coupled to each intermittent photogenerator is connected to the planar lightwave circuits coupled to the two neighboring photogenerators, and the lights emitted from the intermittent photogenerator and those of the two photogenerators neighboring thereto can be specified to a condition selected from the group consisting of: the condition of the same wavelength and the condition of different wavelengths.
Other aspects and advantages of the present invention will become apparent from the following detailed description, taken in conjunction with the accompanying drawings, illustrating by way of example the principles of the present invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic illustration of a conventional optical gas sensor used for detecting a specific gas
FIG. 2A is a schematic illustration of an apparatus for sensing plural gases according to a preferred embodiment of the invention.
FIG. 2B is a schematic illustration of an isolating element used in the apparatus for sensing plural gases of the invention.
FIG. 3A is a schematic diagram showing optic gaps being formed in the sensing pathway according to a preferred embodiment of the invention.
FIG. 3B is a schematic diagram showing optic gaps being formed in the reference pathway according to a preferred embodiment of the invention.
FIG. 4 is a schematic illustration of an apparatus for sensing plural gases according to another preferred embodiment of the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
For your esteemed members of reviewing committee to further understand and recognize the fulfilled functions and structural characteristics of the invention, several preferable embodiments cooperating with detailed description are presented as the follows.
Please refer to FIG. 2A , which is a schematic illustration of an apparatus for sensing plural gases according to a preferred embodiment of the invention. The apparatus for sensing plural gases 2 of FIG. 2A is formed on a substrate 20 , which can be made of a semiconductor material, a polymer, a metal or a flexible material. The apparatus 2 comprises a photogenerator 21 , a planar lightwave circuit 22 , a filter 23 and at least a photodetectors 24 . In this preferred embodiment, there are two photodetectors, however, the number of the photodetectors is not limited thereby. The planar lightwave circuit 22 is coupled to the photogenerator 21 by an input port 223 thereof for enabling the same to receive the signal light emitted from the photogenerator 21 . It is noted that photogenerator 21 can be an edge-emitting laser diode, a surface-emitting laser diode, or a light emitting diode, that is chosen with respect to the type of gas to be sensed.
The planar lightwave circuit 22 further has a sensing pathway 221 and a reference pathway 222 . As seen in FIG. 2A , the sensing pathway 221 is split into two waveguide branches 2212 , 2213 , each having an optic gap 2210 formed thereon, and then the two waveguide branches 2212 , 2213 are merged into a pathway. Moreover, the sensing pathway 221 has at least an output port 2211 , where a filter 23 and a photodetector 24 is disposed by arranging the filter 23 at a position between the output port 2211 and the photodetector 24 . Similarly, the reference pathway 222 also is split into two waveguide branches 2224 , 2225 , each having an optic gap 2220 formed thereon, and then the two waveguide branches 2224 , 2225 are merged into a pathway. Moreover, the reference pathway 222 also has at least an output port 2223 , where a filter 23 and a photodetector 24 is disposed by arranging the filter 23 at a position between the output port 2223 and the photodetector 24 . It is noted that the number of waveguide branch, such as the waveguide branches 2212 , 2213 of the sensing pathway 221 and the waveguide branches 2224 , 225 of the reference pathway 222 , is not limited by two as that shown in the embodiment of FIG. 2A , that the number of waveguide branch can be three for both the sensing pathway 221 and the reference pathway 222 as those shown in FIG. 3A and FIG. 3B . The purpose of arranging waveguide branches in a pathway is to increase the contact between the signal light and the gases to be sensed so that the accuracy of a measurement using the apparatus can be improved.
In this preferred embodiment of the invention, the interval of the optic gap 2210 formed in the sensing pathway 221 is the same as that in the reference pathway 222 , and the length of the sensing pathway 221 is the same as that of the reference pathway 222 .
Please refer to FIG. 2B , which is a schematic illustration of an isolating element used in the apparatus for sensing plural gases of the invention. The arrangement of the reference pathway 222 in the planar lightwave circuit 22 is to provide a reference for a measurement, whereas gas used to obtain the reference is air. In order to prevent the gases to be sensed from mixing with air, an isolating element is used to seal each optic gap 2220 on each waveguide branches 2224 , 2225 of the reference pathway 222 , that the isolating element is comprised of two isolating block 2222 , used to filled the two sides of an optic gap, and an isolating plate 2221 , used to cover the top of the optic gap. The apparatus of this embodiment further comprises a control circuit coupled respectively to the photogenerator 21 and the photodetectors 24 . The control circuit is used to control the signal light to be emitted by the photogenerator 21 and to process the electric signals generated by the photodetectors 24 . Operationally, the light emitted by the photogenerator 21 will be fed into the planar light wave circuit 22 through the input port 223 thereof, and then the light is split and guided by the operation of the planar light wave circuit 22 to be fed into the sensing pathway 221 and the reference pathway 222 . The light entering the sensing pathway 221 will contact the gases to be sensed at the optic gaps 2210 thereof where the intensity of the light is varied by the absorption of the gases acting on the light, and the intensity-varied light pass the filter 23 and enter the photodetector 24 for enabling the photodetector 24 to issue a response signal accordingly. On the other hand, the light entering the reference pathway 222 will be blocked from contacting the gases to be sensed since the optic gaps thereof is sealed by the isolating element 2221 so that the intensity of the light is maintained unchanged, and then the intensity-unchanged light pass the filter 23 and enter the photodetector 24 for enabling the photodetector 24 to issue a reference signal accordingly. The filter 23 is used to isolate lights other than the intended light emitted from the photogenerator 21 from entering the photodetector 24 , and the photodetector 24 is used to convert the received response/reference signal into a corresponding electric signal. In addition, in order to prevent the accuracy of the apparatus 2 of the invention to be adversely affected by the pollution of dust or dirt depositing in the optic gaps, a separation film is provided for isolating dust and dirt from entering the apparatus 2 while allowing the plural gases to pass through.
Please refer to FIG. 4 , which is a schematic illustration of an apparatus for sensing plural gases according to another preferred embodiment of the invention. The apparatus for sensing plural gases 3 is formed on a substrate 30 , that is basically used for detecting three different gases. The structure of the apparatus 3 is similar to the apparatus 2 shown in FIG. 2A and the only difference between the two is that the apparatus 3 has three planar lightwave circuit and the devices corresponding thereto. The apparatus 3 has a first planar lightwave circuit 34 , a second planar lightwave circuit 35 and a third planar lightwave circuit 36 , wherein the input port of the first planar lightwave circuit 34 is coupled to a first photogenerator 31 , and the input port of the second planar lightwave circuit 35 is coupled to a third photogenerator 33 , and the input port of the third planar lightwave circuit 36 is coupled to a intermittent photogenerator 32 . Furthermore, the substrate 30 can be made of a semiconductor material, a polymer, a metal or a flexible material; the wavelengths of the lights emitted from the first photogenerator 31 , the intermittent photogenerator 32 and the third photogenerator 33 can be different from each other and each of the three photogenerator 31 , 32 , 33 can be a device selected from the group consisting of an edge-emitting laser diode, a surface-emitting laser diode, and a light emitting diode. It is noted that the wavelength of light emitted by the three respectively is chosen with respect to the type of gas to be sensed.
The third planar lightwave circuit 36 is split into two waveguide branches 361 , which are connected respectively to the first planar lightwave circuit 34 and the second planar lightwave circuit 35 . As seen in FIG. 4 , the configuration of the first planar lightwave circuit 34 is the same as that of the second planar lightwave circuit 35 , that the first planar lightwave circuit 34 has a sensing pathway 341 and a reference pathway 342 while the second planar lightwave circuit 35 has a sensing pathway 351 and a reference pathway 352 . Each of the two sensing pathways 341 , 351 is split into two waveguide branches, each having an optic gap formed thereon, i.e. optic gap 3410 of the first planar lightwave circuit 34 and the optic gap 3510 for the second planar lightwave circuit 35 , and then the two waveguide branches are merged into a pathway. Moreover, each of the two sensing pathways 341 , 351 has at least an output port, where a filter and a photodetector is disposed by arranging the filter at a position between the output port and the photodetector, i.e. the filter 371 and the photodetector 381 for the sensing pathway 341 and the filter 373 and the photodetector 383 for the sensing pathway 351 . Similarly, each of the two reference pathways 342 , 352 also is split into two waveguide branches, each having an optic gap formed thereon, and then the two waveguide branches are merged into a pathway. Moreover, each of the reference pathways 342 , 352 also has at least an output port, where a filter and a photodetector is disposed by arranging the filter at a position between the output port and the photodetector, i.e. the filter 372 and the photodetector 382 for the reference pathway 342 and the filter 374 and the photodetector 384 for the reference pathway 352 . In order to prevent the gases to be sensed from mixing with air, an isolating element, i.e. the two isolating elements 3420 , 3520 shown in FIG. 4 , is used to seal each optic gap on each waveguide branches of the reference pathways 342 , 352 . It is noted that the principle of detection of the apparatus shown in FIG. 4 is the same as that shown in FIG. 2A , and thus is not described further herein.
By the proper application of planar lightwave circuit, the apparatus of the invention has advantages list as following: (1) The structure of the apparatus can be flattened for enabling the same to be a thin gas sensor; (2) the apparatus of the invention can be adapted to detect and measure plural gases while the number of gases can be numerous; (3) the signal response time is shortened; (4) the apparatus of the invention can have high accuracy and better long-term stability.
From the above description, it is noted that all the number of the device used in the apparatus for sensing plural gases of the present invention, such as the numbers of the input port of the planar lightwave circuit, the number of the reference pathway, the number of the sensing pathway, and so on, are only used for illustration and are not limited thereby. In summary that this invention has been disclosed and illustrated with reference to particular embodiments, the principles involved are susceptible for use in numerous other embodiments that will be apparent to persons skilled in the art. Consequently, the present invention has been examined to be progressive and has great potential in commercial applications.
While the preferred embodiment of the invention has been set forth for the purpose of disclosure, modifications of the disclosed embodiment of the invention as well as other embodiments thereof may occur to those skilled in the art. Accordingly, the appended claims are intended to cover all embodiments which do not depart from the spirit and scope of the invention. | The apparatus for sensing plural gases is substantially a gas sensor adopting planar lightwave circuit for constructing reference optical path and sensing optical path, which is a flat structure with abilities of high accuracy, long-term stability, and short response time. The gas sensor can be widely applied for monitoring the safety of a working environment, securing the safety of workers, alerting potential hazard in a factory, inspecting harmful materials in a specific area, testing leakage of a pipeline, inspecting waste gas exhausted from automobile/motorcycle, and monitoring the living quality of household environment. | 6 |
BACKGROUND OF THE INVENTION
[0001] The product is a formulation of pure sustained release oral dosage micropellets in a capsule which contains dichroa febrifuga alkone derivative (DFAD) when taken by a patient and are comprised of inner seeds coated with DFAD. The oral dosage formulation is administered by separating the upper and lower parts of the capsule and placing the micropellets on drug. A delay in absorption was found and the bioavailability was reduced significantly.
[0002] There is thus a need for a slow-release DFAD composition which provides satisfactory bioavailability and absorption pattern when taken orally with drug.
[0003] The oral sustained release DFAD formulation of the present invention provides a means to administer DFAD in a micropellet formulation which enables patients to receive the correct therapeutic blood level of DFAD.
[0004] The micropellets of this invention are utilized in an easily openable capsule containing a sufficient amount of micropellets to provide a dosage unit of DFAD. The dosage unit administered to a patient is determined by the age, size and condition of the patient as well as the severity of the disease.
DESCRIPTION OF THE PRIOR ART
[0005] The natural source of DFAD is abounding. DFAD is extracted from plant named dichroa febrifuga (Blue Evergreen Hydrangea ). The plant has 4 to 8 inch long dark green resemble the foliage of Hydrangea with prominent veins and small serrations. The terminal end of the branches hold clusters of Hydrangea -like flowers with white buds opening to bright blue flowers in spring and summer that are followed by metallic blue berries. As with the blue forms of Hydrangea the shade of blue of the flower is determined by soil pH and more acid soils produce bluer flowers. Plant in part sun to light shade with moderately moist soil. It is hardy and evergreen to 20-25 degrees F. but defoliates such below these temperatures but plants knocked back by cold resprout from hard wood. Dichroa febrifuga is native to Nepal eastwards to southern China and into south-east Asia, where it grows at the forest edge. The specific epithet febrifuga is in reference to the use of the plant as a febrifuge, acting to reduce fever. Its use as such is reported in China.
[0006] Febrifugine was isolated from plant and synthesis. For example, febrifugines is isolated cis-febrifugine and trans-febrifugine from Hydrangea macrophylla (Saxifragaceae); these compounds had already been isolated from Dichroa febrifuga (antimalarial natural drug) by Koepfli et al. in 1947 and from Hydrangea umbellate by Ablondi et al. in 1952. Synthesis of febrifugins was first achieved in 1952 by Baker et al., who later reported that febrifugine obtained from D. febrifuga corresponds to the synthetic cis-febrifugine, whereas isofebrifugine corresponds to the synthetic trans-febrifugine. Afterwards, Barringer et al. established through detailed H-NMR analysis that the assignments by Baker et al. should be reversed, i.e., febrifugine has a trans-orientation and isofebrifugine has a cis-configuration. Thus, the absolute configurations of febrifugines were established.
[0007] So far, it has no report regarding a sustained release preparation of DFAD.
DETAILED DESCRIPTION OF THE INVENTION
[0008] A sustained release preparation may be a good thing for patients. It's easier to take a medication once a day than twice a day—and a sustained release version may insure a more steady blood level of the medication.
[0009] Febrifugine and isofebrifugine derived from Chinese hydrangea are known to have strong activities against tropical malarial protozoan. The chemical structures of febrifugine and isofebrifugine are known to show such strong activities against malarial. The activity of these febrifugine compounds have been known from old times as active ingredients of Chinese medicines such as “JOSAN”.
[0010] Malaria is one which of most serious infectious diseases. In the known infectious disease, it is only inferior to human health's harm to pulmonary tuberculosis. According to the World Health Organization reported that world has every 3 to 600,000,000 people infects malaria, dies the approximately 3.000,000 people. In 2005 the 58 th World Health Assembly pointed out: every year malaria continues the death which creates more than 100 ten thousand may prevent, particularly in Africa's babies and other frail crowds, and this disease continues to threaten the Americans, Asians and the Pacific section several million person of lives. Although the existing medicine (for example quinoline chloroquinoline and so on) has certain curative effect to malaria, but the human body will have the drug resistance rapidly in the course of treatment. As early as in ancient China used the saxifragaceae Chinerse herb dichroa febrifuga to use in the malaria shot.
[0011] The following specific examples will provide detailed illustration of methods of producing DFAD according to the present invention and pharmaceutical dosage units containing DFAD. Moreover, examples will be given by way of pharmaceutical testing performed with DFAD to demonstrate its effectiveness. These examples are not intended, however, to limit or restrict the scope of the invention in any way, and should not be construed as providing conditions, parameters, reagents, or starting materials which must be utilized exclusively in order to practice the present invention.
EXAMPLE 1
[0012] 1 kg polyvinylpyrrolidone (PPD) (molecular weight 40.000) were dissolved in 10 liter of isopropand, and 1 kg of micronized DFAD were dispersed in there. 3.5 kg of sugar was placed in suspension and mix. The DFAD is coated onto the sugar seed by first combining it with a water soluble system such as polyethylene glycol or polyvinylpyrrolidone.
[0013] The resulting DFAD coated sugar seeds are then coated with a pharmaceutically acceptable waterinsoluble system such as ethylcellulose, cellulose acetate butyrate or cellulose triacetate, with ethyl cellulose preferred. This coating enables release of the DFAD. The average diameter of each of the finished micropellets is about 0.4 to 0.6 mm, preferably about 0.5 mm. This provides a coating with a sufficient amount of channels to enable the DFAD to be released.
[0014] The dissolution rate depends on the weight of the micropellets and solvent system.
[0015] The pellets were screened.
[0016] As desired, the final coated products containing an ethylcellulose coating level of 1% was prepared. The pellets were dried under vacuum.
[0017] The products contained 99.0% by weight of DFAD and 1% by weight ethylcellulose coating.
EXAMPLE 2
[0018] Plasma concentration of DFAD in rat was determined by regular methods.
[0000]
Plasma Concentrating of DFAD
Regular preparation of DFAD
Sustained release of DFAD
1 h
75 mg/ml
60 mg/ml
2 h
68 mg/ml
55 mg/ml
4 h
52 mg/ml
45 mg/ml
8 h
42 mg/ml
38 mg/ml
24 h
21 mg/ml
28 mg/ml
48 h
15 mg/ml
20 mg/ml
72 h
8 mg/ml
16 mg/ml
[0019] The data in table shows that plasma concentration of DFAD in sustained preparation was not significantly different from DFAD in regular preparation before 8 hours. But it did after 8 hours. The data shows that bioavailability of sustained release preparation of DFAD is better than regular preparation of DFAD.
EXAMPLE 3
[0020] The formation of an inclusion complex of a medical compound with DFAD in accordance with the process described above was confirmed by various methods such as powder X-ray diffraction, dissolution behavior, scanning electron microscope analysis, differential thermal analysis (DTA) and infrared absorption (IR). Inclusion complexes were prepared using DFAD as a medical compound, and the behavior of dissolution and release of DFAD from the inclusion complex in the capsule form, as well as the behavior of dissolution and release of DFAD from compressed capsule containing the inclusion complex were determined.
[0021] The characteristic peaks of the individual components have disappeared, but instead, such a diffraction pattern which is different from the diffraction patterns of a physical mixture of both the components has been given. These results of the X-ray diffraction patterns support the fact that DFAD and a pharmaceutical acceptable have complex with each other and formed an inclusion complex of them having a structure different from the original structures of the individual components.
EXAMPLE 4
[0022] To demonstrate the behaviors of dissolution and release of the medical compound from the sustained release pharmaceutical composition according to this particular embodiment of this invention, the following tests were conducted. Thus, an inclusion complex of DFAD shows a highly controlled release rate of the tablet samples. The respective tablet samples were separately placed into water and release into water from the tablet was determined with lapse of time which exhibits a similar variation in the amount of DFAD as dissolved and released from a tablet sample. It is observed that the DFAD was absorbed promptly into the blood and disappeared quickly from the blood when the original tablet which is mixture of DFAD with starch in the compressed tablet form was orally given, and that in contrast, pure sustained release of DFAD was maintained in the blood at substantially steady concentrations for prolonged period of time.
EXAMPLE 5
[0023] The novelty of the present invention resides in the mixture of the active ingredients in the specified proportions to produce DFAD and in the preparation of dosage units in pharmaceutically acceptable dosage form. The tern “pharmaceutical acceptable dosage form” as used hereinabove includes any suitable vehicle for the administration of medications known in the pharmaceutical art, including, by way of example, tablets, capsules, syrups, and elixirs with specified ranges of DFAD concentration. | Now is provided a new sustained release drug preparation comprising such an inclusion complex of a medical compound with dichroa febrifuga alkone derivative (DFAD), which sustains or retards the dissolution and release of the DFAD at a controlled rate from the inclusion complex and hence from the drug preparation containing the DFAD, so as to maintain the concentration of the DFAD in blood at an effective level for prolonged time. | 0 |
CROSS REFERENCE OF RELATED APPLICATION
[0001] This is a national phase national application of an international patent application number PCT/CN2012/072664 with a filing date of Mar. 21, 2012, which claimed priority of a foreign application number 201110072090.1 with a filing date of Mar. 24, 2011 in China. The contents of these specifications, including any intervening amendments thereto, are incorporated herein by reference.
BACKGROUND OF THE PRESENT INVENTION
[0002] 1. Field of Invention
[0003] The present invention relates to a water treatment agent which removes contaminant through oxidation process.
[0004] 2. Description of Related Arts
[0005] With rapid industrial and agriculture development, a large amount of toxic and hazardous organic pollutants which are difficult to degrade are discharged into the water system, thus causing serious pollution problems to the surface water source and the groundwater source and continuous deterioration of water quality. At present, chemical oxidants such as chlorine, chlorine dioxide, hydrogen peroxide, ozone and potassium permanganate are utilized to remove organic pollutants in water through oxidation process. Ozone has high oxidation ability and high adaptability to water quality, but the investment cost and the operation cost are very high and the formation of bromate which is carcinogenic is problematic. Although hydrogen peroxide does not have high oxidation property by itself, hydroxyl radicals of strong oxidation property will be formed by reaction with ferrous ion under acid conditions. The resulting hydroxyl radical has very strong oxidation ability but the pH value of water subject to treatment has to be monitored and adjusted continuously during the reaction process, thus the process is too complicated and difficult to control. Chlorine dioxide has a very strong disinfection capability. However, the use of chlorine dioxide will lead to the formation of byproduct chlorite through reaction with organic substances in which chlorite has damaging effect to red blood cell and therefore the use of chlorine dioxide has safety hazards issues. Chlorine has certain level of oxidation capability in treating organic substances and has been used in pre-oxidation for water treatment for a long period of time. However, a series of halogenated by-products, which is hazardous to health, are formed through reactions between chlorine and different organic contaminants in water. Accordingly, the use of chlorine in pre-oxidation process of water treatment is restricted. Potassium permanganate has a relatively strong oxidizing ability on the removal of organic pollutants in water and does not produce toxic and hazardous by-products, however, organic substances have very high level of and therefore only organic substances with unsaturated functional group, such as olefin and phenolic compounds, can be oxidized and removed. The toxic and hazardous pollutants which is difficult to degrade has a very low reaction activity with potassium permanganate and therefore the removal rate is not high. Accordingly, further research and development on a water treatment agent which has strong oxidation capability and no production of toxic and hazardous by-products is required.
SUMMARY OF THE PRESENT INVENTION
[0006] An object of the present invention is to provide water treatment agent for removing contaminants through oxidation with highly active manganese (V) intermediate which solves the problems of low oxidation ability and production of toxic and hazardous by-products of existing chemicals (such as chlorine, chlorine dioxide, hydrogen peroxide, ozone and potassium permanganate) used in water treatment.
[0007] The water treatment agent for removing contaminants through oxidation with highly active manganese (V) intermediate according to the first preferred embodiment of the present invention is composed of bivalent manganese ions, ligand and persulfate, wherein a molar ratio of the bivalent manganese ions, the ligand, and the persulfate is 1:(1-50):(1-1000). The bivalent manganese ions is obtained from at least one of the group consisting of manganese chloride, manganese sulfate and manganese nitrate.
[0008] The water treatment agent for removing contaminants through oxidation with highly active manganese (V) intermediate according to the second preferred embodiment of the present invention is composed of permanganate, ligand and persulfate, wherein a molar ratio of the permanganate, the ligand, and the persulfate is 1:(1-50):(1-1000). The permanganate is potassium permanganate and/or sodium permanganate.
[0009] The water treatment agent for removing contaminants through oxidation with highly active manganese (V) intermediate according to the third preferred embodiment of the present invention is composed of manganese dioxide, ligand and persulfate, wherein a molar ratio of the manganese dioxide, the ligand, and the persulfate is 1:(1-50):(1-1000).
[0010] In the water treatment agent for removing contaminants through oxidation with highly active manganese (V) intermediate according to the first, the second and the third preferred embodiment of the present invention, the persulfate is peroxomonosulfate (MHSO 5 , M=K, Na or NH 4 ) and/or peroxodisulfate (A 2 S 2 O 8 , A=K, Na or NH 4 ); the ligand is inorganic ligand, low molecular weight carboxylic acid, amino acid, aminoxatyl ligand, high molecular weight carboxylic acid or organic phosphonic acid.
ADVANTAGEOUS EFFECT
[0011] In the presence of ligand, the rapid and in situ reaction between bivalent manganese ions, permanganate or manganese dioxide and persulfate can result in the producing of highly active manganese (V) intermediate. The highly active manganese (V) intermediate produced from in situ reaction has strong oxidizing activity which is capable of removing the organic pollutants in water at a faster rate while no toxic and harmful by-products are produced.
[0012] The principle of highly active manganese (V) intermediate production is explained by using bivalent manganese ions, ligand and peroxomonosulfate as the example of illustration as follows:
[0013] In the presence of ligand (Ligand, L), peroxomonosulfate (HSO 5 − ) is catalyzed by Mn(II) to produce trivalent manganese (Mn(III)L) and sulfate radical (SO 4 − ), which is shown in Reaction (1); then the Mn(III)L from Reaction (I) reacts with peroxomonosulfate (HSO 5 − ) in which two-electron transfer process in oxygen is occurred, then highly active manganese (V) intermediate (Mn(V)L) and sulfate (SO 4 − ) are produced, which is shown in Reaction (2). The Mn(V)L can be reduced to Mn(III)L in the process of oxidation and degradation of organic substances, then the Mn(III)L can catalyze the peroxomonosulfate (HSO 5 − ) to produce Mn(V)L and SO 4 − and the reaction can be carried out continuously.
[0000] Mn(II)+HSO 5 − +L→Mn(III)L+SO 4 − Reaction (1)
[0000] Mn(III)L+HSO 5 − →Mn(V)L+SO 4 2− Reaction (2)
[0014] The water treatment agent of the present invention can be used for processing source water, polluted water or secondary effluent from sewage plant and meet the corresponding national standards.
[0015] Still further objects and advantages will become apparent from a consideration of the ensuing description and drawings.
[0016] These and other objectives, features, and advantages of the present invention will become apparent from the following detailed description, the accompanying drawings, and the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] FIG. 1 is a graph showing the relationship between the removal rate of atrazine and the HRT according to exemplary embodiment 21 of a preferred embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0018] The preferred embodiment of the present invention is further described and includes all combinations and modifications encompassed within the spirit and scope of the followings.
Exemplary Embodiment 1
[0019] The water treatment agent for removing contaminants through oxidation with highly active manganese (V) intermediate according to the first preferred embodiment of the present invention is composed of bivalent manganese ions, ligand and persulfate, wherein a molar ratio of the bivalent manganese ions, the ligand, and the persulfate is 1:(1-50):(1-1000).
[0020] According to this preferred embodiment of the present invention, the bivalent manganese ions, the ligand and the persulfate are stored separately. The bivalent manganese ions can be stored in solid state compound or liquid state ions.
[0021] According to this preferred embodiment of the present invention, in the presence of ligand, the rapid and in situ reaction between bivalent manganese ions and persulfate can result in the producing of highly active manganese (V) intermediate. The highly active manganese (V) intermediate produced from in situ reaction has strong oxidizing activity which is capable of removing the organic pollutants in water at a faster rate while no toxic and harmful by-products are produced.
[0022] According to this preferred embodiment of the present invention, a water treatment method which utilizes the water treatment agent for removing contaminants through oxidation with highly active manganese (V) intermediate comprises the following steps: (a) adding bivalent manganese ions and ligand into the water subject to treatment and mixing uniformly, then adding persulfate and maintaining a concentration of bivalent manganese ions at 0.5˜100 μmol/L, where a molar ratio of the bivalent manganese ions, the ligand, and the persulfate is 1:(1-50):(1-1000) and a hydraulic retention time is 1˜180 min; (b) carrying out routine water treatment process, which includes coagulation processing, sedimentation processing and filtration processing. In the step (a), the water subject to treatment is source water, polluted water or secondary effluent from sewage plant.
[0023] According to this preferred embodiment of the present invention, in the presence of ligand (Ligand, L), peroxomonosulfate (HSO 5 − ) is catalyzed by Mn(II) to produce trivalent manganese (Mn(III)L) and sulfate radical (SO 4 − ), which is shown in Reaction (1); then the Mn(III)L from Reaction (I) reacts with peroxomonosulfate (HSO 5 − ) in which two-electron transfer process in oxygen is occurred, then highly active manganese (V) intermediate (Mn(V)L) and sulfate (SO 4 − ) are produced, which is shown in Reaction (2). The Mn(V)L can be reduced to Mn(III)L in the process of oxidation and degradation of organic substances, then the Mn(III)L can catalyze the peroxomonosulfate (HSO 5 − ) to produce Mn(V)L and SO 4 − and the reaction can be carried out continuously.
[0000] Mn(II)+HSO 5 − +L→Mn(III)L+SO 4 − Reaction (1)
[0000] Mn(III)L+HSO 5 − →Mn(V)L+SO 4 2− Reaction (2)
Exemplary Embodiment 2
[0024] The difference between this embodiment and the exemplary embodiment 1 is that a molar ratio of the bivalent manganese ions, the ligand, and the persulfate is 1:(2-40):(5-800). Other parameters and conditions are the same as that of the exemplary embodiment 1.
Exemplary Embodiment 3
[0025] The difference between this embodiment and the exemplary embodiment 1 is that a molar ratio of the bivalent manganese ions, the ligand, and the persulfate is 1:(3-30):(10-600). Other parameters and conditions are the same as that of the exemplary embodiment 1.
Exemplary Embodiment 4
[0026] The difference between this embodiment and the exemplary embodiment 1 is that a molar ratio of the bivalent manganese ions, the ligand, and the persulfate is 1:(5-20):(15-400). Other parameters and conditions are the same as that of the exemplary embodiment 1.
Exemplary Embodiment 5
[0027] The difference between this embodiment and the exemplary embodiment 1 is that a molar ratio of the bivalent manganese ions, the ligand, and the persulfate is 1:(6-15):(20-200). Other parameters and conditions are the same as that of the exemplary embodiment 1.
Exemplary Embodiment 6
[0028] The difference between this embodiment and the exemplary embodiment 1 is that a molar ratio of the bivalent manganese ions, the ligand, and the persulfate is 1:(7-10):(25-100). Other parameters and conditions are the same as that of the exemplary embodiment 1.
Exemplary Embodiment 7
[0029] The difference between this embodiment and the exemplary embodiment 1 is that a molar ratio of the bivalent manganese ions, the ligand, and the persulfate is 1:8.3:30. Other parameters and conditions are the same as that of the exemplary embodiment 1.
Exemplary Embodiment 8
[0030] The difference between this embodiment and the exemplary embodiments 1 to 7 is that. the bivalent manganese ions is selected from at least one of the group consisting of manganese chloride, manganese sulfate and manganese nitrate. Other parameters and conditions are the same as that of one of the exemplary embodiments 1 to 7.
[0031] According to this exemplary embodiment, if the bivalent manganese ions is a mixture from two or more of the manganese chloride, the manganese sulfate and the manganese nitrate, the ratio of different components in the mixture is not restricted.
Exemplary Embodiment 9
[0032] The difference between this embodiment and the exemplary embodiments 1 to 8 is that the ligand is inorganic ligand, low molecular weight carboxylic acid, amino acid, aminoxatyl ligand, high molecular weight carboxylic acid or organic phosphonic acid. Other parameters and conditions are the same as that of one of the exemplary embodiments 1 to 8.
Exemplary Embodiment 10
[0033] The difference between this embodiment and the exemplary embodiment 9 is that inorganic ligand is one or more of the group selected from phosphate, pyrophosphate and polyphosphates. Other parameters and conditions are the same as that of one of the exemplary embodiment 9.
[0034] According to this exemplary embodiment, if the inorganic ligand is a mixture from two or more of the phosphate, the pyrophosphate and the polyphosphates, the ratio of different components in the mixture is not restricted.
Exemplary Embodiment 11
[0035] The difference between this embodiment and the exemplary embodiment 9 is that the low molecular weight carboxylic acid is one or more of the group selected from oxalic acid, citric acid, tartaric acid, malonic acid, succinic acid, benzoic acid, salicylic acid, phthalic acid, sulfosalicylic acid, maleic acid, fumaric acid, gallic acid and tannic acid. Other parameters and conditions are the same as that of one of the exemplary embodiment 9.
[0036] According to this exemplary embodiment, if the low molecular weight carboxylic acid is a mixture containing two or more components, the ratio of different components in the mixture is not restricted.
Exemplary Embodiment 12
[0037] The difference between this embodiment and the exemplary embodiment 9 is that the aminoxatyl ligand is one or more of the group selected from ethylenediaminetetraacetic acid (EDTA), cyclohexanediamine tetraacetic acid (CDTA), nitrilotriacetic acid (NTA), ethylene glycol bis-aminoethylether tetraacetic acid (EGTA), ethylenediaminetetrapropionic acid, triethylenetetramine, Ethylenediamine-N,N′-disuccinic acid (EDDS), pentetic acid (DTPA), tris(phosphonomethyl)amine (ATMP) and ethylenediamine tetra(methylene phosphonic acid) (EDTMP). Other parameters and conditions are the same as that of one of the exemplary embodiment 9.
[0038] According to this exemplary embodiment, if the aminoxatyl ligand is a mixture containing two or more components, the ratio of different components in the mixture is not restricted.
Exemplary Embodiment 13
[0039] The difference between this embodiment and the exemplary embodiment 9 is that the high molecular weight carboxylic acid is one or more of the group selected from humic acid, fulvic acid and alginic acid. Other parameters and conditions are the same as that of one of the exemplary embodiment 9.
[0040] According to this exemplary embodiment, if the high molecular weight carboxylic acid is a mixture containing two or more components, the ratio of different components in the mixture is not restricted.
Exemplary Embodiment 14
[0041] The difference between this embodiment and the exemplary embodiment 9 is that the organic phosphonic acid is one or more of the group selected from hydroxyethylidene diphosphonic acid (1-Hydroxy Ethylidene-1,1-Diphosphonic Acid), 1-aminoethylene diphosphonic acid, amino trimethylene phosphonic acid, ethylene diamine tetra (methylene phosphonic Acid), 2-phosphonobutane-1,2,4-tricarboxylic acid, diethylene triamine penta (methylene phosphonic acid), hexamethylenediamine tetra(methylene phosphonic acid), glycine dimethyl phosphonic acid, dimethylamine phosphonic acid, hydroxy-trimethylene phosphonic acid, sodium 1,1′-diphosphono propionyloxy phosphonate, polyether methylene phosphonate, and phosphono polyacrylic acid. Other parameters and conditions are the same as that of one of the exemplary embodiment 9.
[0042] According to this exemplary embodiment, if the organic phosphonic acid is a mixture containing two or more components, the ratio of different components in the mixture is not restricted.
Exemplary Embodiment 15
[0043] The difference between this embodiment and the exemplary embodiments 1 to 14 is that the persulfate is peroxomonosulfate MHSO 5 , where M equals to K, Na or NH 4 ; or peroxodisulfate A 2 S 2 O 8 , whee A equals to K, Na or NH 4 . Other parameters and conditions are the same as that of one of the exemplary embodiments 1 to 14.
Exemplary Embodiment 16
[0044] The water treatment agent for removing contaminants through oxidation with highly active manganese (V) intermediate according to the second preferred embodiment of the present invention, the difference between this embodiment and the exemplary embodiments 1 to 15 is that permanganate is used instead of the bivalent manganese ions. Other parameters and conditions are the same as that of one of the exemplary embodiments 1 to 15.
[0045] According to this preferred embodiment of the present invention, in the presence of ligand, trivalent manganese is produced through reaction between permanganate and pollutants in the water subject to treatment, and the rapid and in situ reaction between trivalent manganese and persulfate can result in the producing of highly active manganese (V) intermediate. The highly active manganese (V) intermediate production from in situ reaction has strong oxidizing activity which is capable of removing the organic pollutants in water at a faster rate while no toxic and harmful by-products are produced.
[0046] According to this preferred embodiment of the present invention, a water treatment method which utilizes the water treatment agent for removing contaminants through oxidation with highly active manganese (V) intermediate comprises the following steps: (a) adding permanganate and ligand into the water subject to treatment and mixing uniformly, then adding persulfate and maintaining a concentration of permanganate at 0.5˜100 μmol/L, where a molar ratio of the permanganate, the ligand, and the persulfate is 1:(1-50):(1-1000) and a hydraulic retention time is 1˜180 min; (b) carrying out routine water treatment process, which includes coagulation processing, sedimentation processing and filtration processing. In the step (a), the water subject to treatment is source water, polluted water or secondary effluent from sewage plant.
Exemplary Embodiment 17
[0047] The difference between this embodiment and the exemplary embodiment 16 is that the permanganate is potassium permanganate and/or sodium permanganate. Other parameters and conditions are the same as that of one of the exemplary embodiment 16.
[0048] According to this exemplary embodiment, if the permanganate is a mixture of potassium permanganate and sodium permanganate, the ratio of different components in the mixture is not restricted.
Exemplary Embodiment 18
[0049] The water treatment agent for removing contaminants through oxidation with highly active manganese (V) intermediate according to the third preferred embodiment of the present invention, the difference between this embodiment and the exemplary embodiments 1 to 15 is that manganese dioxide is used instead of the bivalent manganese ions. Other parameters and conditions are the same as that of one of the exemplary embodiments 1 to 15.
[0050] According to this preferred embodiment of the present invention, in the presence of ligand, bivalent or trivalent manganese is produced through reaction between manganese dioxide and pollutants in the water subject to treatment, and the rapid and in situ reaction between bivalent or trivalent manganese and persulfate can result in the producing of highly active manganese (V) intermediate. The highly active manganese (V) intermediate produced from in situ reaction has strong oxidizing activity which is capable of removing the organic pollutants in water at a faster rate while no toxic and harmful by-products are produced.
[0051] According to this preferred embodiment of the present invention, a water treatment method which utilizes the water treatment agent for removing contaminants through oxidation with highly active manganese (V) intermediate comprises the following steps: (a) adding manganese dioxide and ligand into the water subject to treatment and mixing uniformly, then adding persulfate and maintaining a concentration of manganese dioxide at 0.5˜100 μmol/L, where a molar ratio of the manganese dioxide, the ligand, and the persulfate is 1:(1-50):(1-1000) and a hydraulic retention time is 1˜180 min; (b) carrying out routine water treatment process, which includes coagulation processing, sedimentation processing and filtration processing. In the step (a), the water subject to treatment is source water, polluted water or secondary effluent from sewage plant.
Exemplary Embodiment 19
[0052] The water treatment agent for removing contaminants through oxidation with highly active manganese (V) intermediate according to this embodiment is composed of bivalent manganese ions, ethylenediaminetetraacetic acid (EDTA) as ligand and peroxomonosulfate, wherein a molar ratio of the bivalent manganese ions and the ligand is 1:8.3 and a molar ratio of the bivalent manganese ions and the peroxomonosulfate is 1:30, wherein the bivalent manganese ions is selected from at least one of the group consisting of manganese chloride, manganese sulfate and manganese nitrate, wherein the peroxomonosulfate is MHSO 5 , where M equals to K, Na or NH 4 .
[0053] According to this exemplary embodiment, if the bivalent manganese ions is a mixture containing different components, the ratio of different components in the mixture is not restricted.
[0054] According to this preferred embodiment of the present invention, EDTA is used as the ligand, bivalent manganese complex is formed by the EDTA and the bivalent manganese ions which is then undergone the rapid and in situ reaction with the peroxomonosulfate to produce the highly active manganese (V) intermediate. The highly active manganese (V) intermediate produced from the in situ reaction has strong oxidizing activity which is capable of removing the organic pollutants in water at a faster rate while no toxic and harmful by-products are produced.
[0055] According to this preferred embodiment of the present invention, a water treatment process which utilizes the water treatment agent for removing contaminants through oxidation with highly active manganese (V) intermediate in which the water subject to treatment contains 10 μmol/L atrazine comprises the following steps: (a) adding the water treatment agent according to this embodiment into the water subject to treatment which contains 10 μmol/L atrazine, and maintaining a concentration of EDTA at 167 μmol/L, a concentration of bivalent manganese ions at 20 μmol/L and a concentration of peroxomonosulfate at 600 μmol/L, where a hydraulic retention time is 25 min; (b) carrying out routine water treatment process, which includes coagulation processing, sedimentation processing and filtration processing. After the water treatment process, the removal rate of atrazine is above 95%, and the relationship between the removal rate of atrazine and the hydraulic retention time is shown in FIG. 1 of the drawings.
Exemplary Embodiment 20
[0056] The water treatment agent for removing contaminants through oxidation with highly active manganese (V) intermediate according to this embodiment is composed of bivalent manganese ions, hydroxy ethylidene diphosphonic acid (HEDP) as ligand and peroxomonosulfate, wherein a molar ratio of the bivalent manganese ions and the ligand is 1:5 and a molar ratio of the bivalent manganese ions and the peroxomonosulfate is 1:50, wherein the bivalent manganese ions is selected from at least one of the group consisting of manganese chloride, manganese sulfate and manganese nitrate, wherein the peroxomonosulfate is MHSO 5 , where M equals to K, Na or NH 4 .
[0057] According to this exemplary embodiment, if the bivalent manganese ions is a mixture containing different components, the ratio of different components in the mixture is not restricted.
[0058] According to this preferred embodiment of the present invention, hydroxy ethylidene diphosphonic acid (organic phosphonic acid) is used as the ligand, bivalent manganese complex is formed by the hydroxy ethylidene diphosphonic acid and the bivalent manganese ions which is then undergone the rapid and in situ reaction with the peroxomonosulfate to produce the highly active manganese (V) intermediate. The highly active manganese (V) intermediate produced from the in situ reaction has strong oxidizing activity which is capable of removing the organic pollutants in water at a faster rate while no toxic and harmful by-products are produced.
[0059] According to this preferred embodiment of the present invention, a water treatment process which utilizes the water treatment agent for removing contaminants through oxidation with highly active manganese (V) intermediate in which the water subject to treatment contains 10 μmol/L atrazine comprises the following steps: (a) adding the water treatment agent according to this embodiment into the water subject to treatment which contains 10 μmol/L atrazine, and maintaining a concentration of bivalent manganese ions at 20 μmol/L, a concentration of peroxomonosulfate at 1000 μmol/L and a concentration of hydroxy ethylidene diphosphonic acid at 100 μmol/L, where a hydraulic retention time is 30 min; (b) carrying out routine water treatment process, which includes coagulation processing, sedimentation processing and filtration processing. After the water treatment process, the removal rate of atrazine is above 96%.
Exemplary Embodiment 21
[0060] The water treatment agent for removing contaminants through oxidation with highly active manganese (V) intermediate according to this embodiment is composed of bivalent manganese ions, nitrilotriacetic acid (NTA) as ligand and peroxomonosulfate, wherein a molar ratio of the bivalent manganese ions and the ligand is 1:5 and a molar ratio of the bivalent manganese ions and the peroxomonosulfate is 1:50, wherein the bivalent manganese ions is selected from at least one of the group consisting of manganese chloride, manganese sulfate and manganese nitrate, wherein the peroxomonosulfate is KHSO 5 .
[0061] According to this exemplary embodiment, if the bivalent manganese ions is a mixture containing different components, the ratio of different components in the mixture is not restricted.
[0062] According to this preferred embodiment of the present invention, a water treatment process which utilizes the water treatment agent for removing contaminants through oxidation with highly active manganese (V) intermediate in which the water subject to treatment contains 20 μmol/L nitrophenol comprises the following steps: (a) adding the water treatment agent according to this embodiment into the water subject to treatment which contains 20 μmol/L nitrophenol, and maintaining a concentration of bivalent manganese ions at 20 μmol/L, a concentration of peroxomonosulfate at 1000 μmol/L and a concentration of NTA at 100 μmol/L, where a hydraulic retention time is 30 min; (b) carrying out routine water treatment process, which includes coagulation processing, sedimentation processing and filtration processing. After the water treatment process, the removal rate of nitrophenol is above 95%.
Exemplary Embodiment 22
[0063] The water treatment agent for removing contaminants through oxidation with highly active manganese (V) intermediate according to this embodiment is composed of bivalent manganese ions, citric acid as ligand and peroxomonosulfate, wherein a molar ratio of the bivalent manganese ions and the ligand is 1:25 and a molar ratio of the bivalent manganese ions and the peroxomonosulfate is 1:50, wherein the bivalent manganese ions is selected from at least one of the group consisting of manganese chloride, manganese sulfate and manganese nitrate, wherein the peroxomonosulfate is KHSO 5 .
[0064] According to this exemplary embodiment, if the bivalent manganese ions is a mixture containing different components, the ratio of different components in the mixture is not restricted.
[0065] According to this preferred embodiment of the present invention, a water treatment process which utilizes the water treatment agent for removing contaminants through oxidation with highly active manganese (V) intermediate in which the water subject to treatment contains 20 μmol/L nitrophenol comprises the following steps: (a) adding the water treatment agent according to this embodiment into the water subject to treatment which contains 20 μmol/L nitrophenol, and maintaining a concentration of bivalent manganese ions at 20 μmol/L, a concentration of peroxomonosulfate at 1000 μmol/L and a concentration of citric acid at 500 μmol/L, where a hydraulic retention time is 60 min; (b) carrying out routine water treatment process, which includes coagulation processing, sedimentation processing and filtration processing. After the water treatment process, the removal rate of nitrophenol is above 90%.
Exemplary Embodiment 23
[0066] The water treatment agent for removing contaminants through oxidation with highly active manganese (V) intermediate according to this embodiment is composed of bivalent manganese ions, alginic acid as ligand and peroxomonosulfate, wherein a molar ratio of the bivalent manganese ions and the ligand is 1:10 and a molar ratio of the bivalent manganese ions and the peroxomonosulfate is 1:30, wherein the bivalent manganese ions is selected from at least one of the group consisting of manganese chloride, manganese sulfate and manganese nitrate, wherein the peroxomonosulfate is KHSO 5 .
[0067] According to this exemplary embodiment, if the bivalent manganese ions is a mixture containing different components, the ratio of different components in the mixture is not restricted.
[0068] According to this preferred embodiment of the present invention, a water treatment process which utilizes the water treatment agent for removing contaminants through oxidation with highly active manganese (V) intermediate in which the water subject to treatment contains 20 μmol/L dimethyl phthalate comprises the following steps: (a) adding the water treatment agent according to this embodiment into the water subject to treatment which contains 20 μmol/L dimethyl phthalate, and maintaining a concentration of bivalent manganese ions at 10 μmol/L, a concentration of peroxomonosulfate at 30 μmol/L and a concentration of alginic acid at 100 μmol/L, where a hydraulic retention time is 60 min; (b) carrying out routine water treatment process, which includes coagulation processing, sedimentation processing and filtration processing. After the water treatment process, the removal rate of dimethyl phthalate is above 90%.
Exemplary Embodiment 24
[0069] The water treatment agent for removing contaminants through oxidation with highly active manganese (V) intermediate according to this embodiment is composed of bivalent manganese ions, 1-aminoethylene diphosphonic acid as ligand and peroxomonosulfate, wherein a molar ratio of the bivalent manganese ions and the ligand is 1:10 and a molar ratio of the bivalent manganese ions and the peroxomonosulfate is 1:100, wherein the bivalent manganese ions is selected from at least one of the group consisting of manganese chloride, manganese sulfate and manganese nitrate, wherein the peroxomonosulfate is KHSO 5 .
[0070] According to this exemplary embodiment, if the bivalent manganese ions is a mixture containing different components, the ratio of different components in the mixture is not restricted.
[0071] According to this preferred embodiment of the present invention, a water treatment process which utilizes the water treatment agent for removing contaminants through oxidation with highly active manganese (V) intermediate in which the water subject to treatment contains 20 μmol/L dimethyl phthalate comprises the following steps: (a) adding the water treatment agent according to this embodiment into the water subject to treatment which contains 20 μmol/L dimethyl phthalate, and maintaining a concentration of bivalent manganese ions at 20 μmol/L, a concentration of peroxomonosulfate at 2000 μmol/L and a concentration of 1-aminoethylene diphosphonic acid at 200 μmol/L, where a hydraulic retention time is 50 min; (b) carrying out routine water treatment process, which includes coagulation processing, sedimentation processing and filtration processing. After the water treatment process, the removal rate of dimethyl phthalate is above 90%.
Exemplary Embodiment 25
[0072] The water treatment agent for removing contaminants through oxidation with highly active manganese (V) intermediate according to this embodiment is composed of bivalent manganese ions, cyclohexanediamine tetraacetic acid (CDTA) as ligand and peroxomonosulfate, wherein a molar ratio of the bivalent manganese ions and the ligand is 1:25 and a molar ratio of the bivalent manganese ions and the peroxomonosulfate is 1:100, wherein the bivalent manganese ions is selected from at least one of the group consisting of manganese chloride, manganese sulfate and manganese nitrate, wherein the peroxomonosulfate is KHSO 5 .
[0073] According to this exemplary embodiment, if the bivalent manganese ions is a mixture containing different components, the ratio of different components in the mixture is not restricted.
[0074] According to this preferred embodiment of the present invention, a water treatment process which utilizes the water treatment agent for removing contaminants through oxidation with highly active manganese (V) intermediate in which the water subject to treatment contains 20 μmol/L phenol comprises the following steps: (a) adding the water treatment agent according to this embodiment into the water subject to treatment which contains 20 μmol/L phenol, and maintaining a concentration of bivalent manganese ions at 10 μmol/L, a concentration of peroxomonosulfate at 1000 μmol/L and a concentration of cyclohexanediamine tetraacetic acid at 250 μmol/L, where a hydraulic retention time is 60 min; (b) carrying out routine water treatment process, which includes coagulation processing, sedimentation processing and filtration processing. After the water treatment process, the removal rate of phenol is above 96%.
Exemplary Embodiment 26
[0075] The water treatment agent for removing contaminants through oxidation with highly active manganese (V) intermediate according to this embodiment is composed of bivalent manganese ions, pentetic acid (DTPA) as ligand and peroxomonosulfate, wherein a molar ratio of the bivalent manganese ions and the ligand is 1:1 and a molar ratio of the bivalent manganese ions and the peroxomonosulfate is 1:10, wherein the bivalent manganese ions is selected from at least one of the group consisting of manganese chloride, manganese sulfate and manganese nitrate, wherein the peroxomonosulfate is KHSO 5 .
[0076] According to this exemplary embodiment, if the bivalent manganese ions is a mixture containing different components, the ratio of different components in the mixture is not restricted.
[0077] According to this preferred embodiment of the present invention, a water treatment process which utilizes the water treatment agent for removing contaminants through oxidation with highly active manganese (V) intermediate in which the water subject to treatment contains 20 μmol/L phenol comprises the following steps: (a) adding the water treatment agent according to this embodiment into the water subject to treatment which contains 20 μmol/L phenol, and maintaining a concentration of bivalent manganese ions at 20 μmol/L, a concentration of peroxomonosulfate at 200 μmol/L and a concentration of pentetic acid at 250 μmol/L, where a hydraulic retention time is 60 min; (b) carrying out routine water treatment process, which includes coagulation processing, sedimentation processing and filtration processing. After the water treatment process, the removal rate of phenol is above 95%.
Exemplary Embodiment 27
[0078] The water treatment agent for removing contaminants through oxidation with highly active manganese (V) intermediate according to this embodiment is composed of bivalent manganese ions, hydroxy ethylidene diphosphonic acid as ligand and peroxomonosulfate, wherein a molar ratio of the bivalent manganese ions and the ligand is 1:40 and a molar ratio of the bivalent manganese ions and the peroxomonosulfate is 1:800, wherein the bivalent manganese ions is selected from at least one of the group consisting of manganese chloride, manganese sulfate and manganese nitrate, wherein the peroxomonosulfate is KHSO 5 .
[0079] According to this exemplary embodiment, if the bivalent manganese ions is a mixture containing different components, the ratio of different components in the mixture is not restricted.
[0080] According to this preferred embodiment of the present invention, a water treatment process which utilizes the water treatment agent for removing contaminants through oxidation with highly active manganese (V) intermediate in which the water subject to treatment contains 10 μmol/L phenol comprises the following steps: (a) adding the water treatment agent according to this embodiment into the water subject to treatment which contains 10 μmol/L phenol, and maintaining a concentration of bivalent manganese ions at 2 μmol/L, a concentration of peroxomonosulfate at 1600 μmol/L and a concentration of pentetic acid at 80 μmol/L, where a hydraulic retention time is 60 min; (b) carrying out routine water treatment process, which includes coagulation processing, sedimentation processing and filtration processing. After the water treatment process, the removal rate of phenol is above 95%.
Exemplary Embodiment 28
[0081] The water treatment agent for removing contaminants through oxidation with highly active manganese (V) intermediate according to this embodiment is composed of permanganate, nitrilotriacetic acid as ligand and peroxomonosulfate, wherein a molar ratio of the permanganate and the ligand is 1:50 and a molar ratio of the permanganate and the peroxomonosulfate is 1:1000, wherein the permanganate is potassium permanganate and/or sodium permanganate, wherein the peroxomonosulfate is MHSO 5 , where M is K, Na or NH 4 .
[0082] According to this exemplary embodiment, if the permanganate is a mixture of potassium permanganate and sodium permanganate, the ratio of different components in the mixture is not restricted.
[0083] According to this preferred embodiment of the present invention, nitrilotriacetic acid is used as the ligand, trivalent manganese complex is formed by the nitrilotriacetic acid and the permanganate which then undergoes the rapid and in situ reaction with the peroxomonosulfate to produce the highly active manganese (V) intermediate. The highly active manganese (V) intermediate produced from the in situ reaction has strong oxidizing activity which is capable of removing the organic pollutants in water at a faster rate while no toxic and harmful by-products are produced.
[0084] According to this preferred embodiment of the present invention, a water treatment process which utilizes the water treatment agent for removing contaminants through oxidation with highly active manganese (V) intermediate in which the water subject to treatment contains 10 μmol/L 2,4-dichlorophenol comprises the following steps: (a) adding the water treatment agent according to this embodiment into the water subject to treatment which contains 10 μmol/L 2,4-dichlorophenol, and maintaining a concentration of permanganate at 8 μmol/L, a concentration of peroxomonosulfate at 8000 μmol/L and a concentration of phosphate at 400 μmol/L, where a hydraulic retention time is 120 min; (b) carrying out routine water treatment process, which includes coagulation processing, sedimentation processing and filtration processing. After the water treatment process, the removal rate of 2,4-dichlorophenol is above 99%.
Exemplary Embodiment 29
[0085] The water treatment agent for removing contaminants through oxidation with highly active manganese (V) intermediate according to this embodiment is composed of permanganate, ethylenediaminetetraacetic acid (EDTA) as ligand and peroxomonosulfate, wherein a molar ratio of the permanganate and the ligand is 1:5 and a molar ratio of the permanganate and the peroxomonosulfate is 1:300, wherein the permanganate is potassium permanganate and/or sodium permanganate, wherein the peroxomonosulfate is MHSO5, where M is K, Na or NH4.
[0086] According to this exemplary embodiment, if the permanganate is a mixture of potassium permanganate and sodium permanganate, the ratio of different components in the mixture is not restricted.
[0087] According to this preferred embodiment of the present invention, ethylenediaminetetraacetic acid (EDTA) is used as the ligand, trivalent manganese complex is formed by reaction between the permanganate and the pollutants in the water subject to treatment which then undergoes the rapid and in situ reaction with the peroxomonosulfate to produce the highly active manganese (V) intermediate. The highly active manganese (V) intermediate produced from the in situ reaction has strong oxidizing activity which is capable of removing the organic pollutants in water at a faster rate while no toxic and harmful by-products are produced.
[0088] According to this preferred embodiment of the present invention, a water treatment process which utilizes the water treatment agent for removing contaminants through oxidation with highly active manganese (V) intermediate in which the water subject to treatment contains 20 μmol/L 2,4-dichlorophenol comprises the following steps: (a) adding the water treatment agent according to this embodiment into the water subject to treatment which contains 20 μmol/L 2,4-dichlorophenol, and maintaining a concentration of permanganate at 20 μmol/L, a concentration of peroxomonosulfate at 6000 μmol/L and a concentration of EDTA at 100 μmol/L, where a hydraulic retention time is 120 min; (b) carrying out routine water treatment process, which includes coagulation processing, sedimentation processing and filtration processing. After the water treatment process, the removal rate of 2,4-dichlorophenol is above 99%.
Exemplary Embodiment 30
[0089] The water treatment agent for removing contaminants through oxidation with highly active manganese (V) intermediate according to this embodiment is composed of permanganate, ethylenediaminetetraacetic acid (EDTA) as ligand and peroxomonosulfate, wherein a molar ratio of the permanganate and the ligand is 1:10 and a molar ratio of the permanganate and the peroxomonosulfate is 1:5, wherein the permanganate is potassium permanganate and/or sodium permanganate, wherein the peroxomonosulfate is MHSO 5 , where M is K, Na or NH 4 .
[0090] According to this exemplary embodiment, if the permanganate is a mixture of potassium permanganate and sodium permanganate, the ratio of different components in the mixture is not restricted.
[0091] According to this preferred embodiment of the present invention, a water treatment process which utilizes the water treatment agent for removing contaminants through oxidation with highly active manganese (V) intermediate in which the water subject to treatment contains 20 μmol/L 4-chlorophenol comprises the following steps: (a) adding the water treatment agent according to this embodiment into the water subject to treatment which contains 20 μmol/L 4-chlorophenol, and maintaining a concentration of permanganate at 20 μmol/L, a concentration of peroxomonosulfate at 1000 μmol/L and a concentration of EDTA at 200 μmol/L, where a hydraulic retention time is 120 min; (b) carrying out routine water treatment process, which includes coagulation processing, sedimentation processing and filtration processing. After the water treatment process, the removal rate of 4-chlorophenol is above 99%.
Exemplary Embodiment 31
[0092] The water treatment agent for removing contaminants through oxidation with highly active manganese (V) intermediate according to this embodiment is composed of permanganate, nitrilotriacetic acid (NTA) as ligand and peroxomonosulfate, wherein a molar ratio of the permanganate and the ligand is 1:2 and a molar ratio of the permanganate and the peroxomonosulfate is 1:20, wherein the permanganate is potassium permanganate and/or sodium permanganate, wherein the peroxomonosulfate is MHSO 5 , where M is K, Na or NH 4 .
[0093] According to this exemplary embodiment, if the permanganate is a mixture of potassium permanganate and sodium permanganate, the ratio of different components in the mixture is not restricted.
[0094] According to this preferred embodiment of the present invention, a water treatment process which utilizes the water treatment agent for removing contaminants through oxidation with highly active manganese (V) intermediate in which the water subject to treatment contains 10 μmol/L bisphenol A comprises the following steps: (a) adding the water treatment agent according to this embodiment into the water subject to treatment which contains 10 μmol/L bisphenol A, and maintaining a concentration of permanganate at 10 μmol/L, a concentration of peroxomonosulfate at 200 μmol/L and a concentration of EDTA at 20 μmol/L, where a hydraulic retention time is 30 min; (b) carrying out routine water treatment process, which includes coagulation processing, sedimentation processing and filtration processing. After the water treatment process, the removal rate of bisphenol A is above 98%.
Exemplary Embodiment 32
[0095] The water treatment agent for removing contaminants through oxidation with highly active manganese (V) intermediate according to this embodiment is composed of permanganate, 1-aminoethylene diphosphonic acid as ligand and peroxomonosulfate, wherein a molar ratio of the permanganate and the ligand is 1:5 and a molar ratio of the permanganate and the peroxomonosulfate is 1:50, wherein the permanganate is potassium permanganate and/or sodium permanganate, wherein the peroxomonosulfate is MHSO 5 , where M is K, Na or NH 4 .
[0096] According to this exemplary embodiment, if the permanganate is a mixture of potassium permanganate and sodium permanganate, the ratio of different components in the mixture is not restricted.
[0097] According to this preferred embodiment of the present invention, a water treatment process which utilizes the water treatment agent for removing contaminants through oxidation with highly active manganese (V) intermediate in which the water subject to treatment contains 10 μmol/L bisphenol A comprises the following steps: (a) adding the water treatment agent according to this embodiment into the water subject to treatment which contains 10 μmol/L bisphenol A, and maintaining a concentration of permanganate at 10 μmol/L, a concentration of peroxomonosulfate at 500 μmol/L and a concentration of 1-aminoethylene diphosphonic acid at 50 μmol/L, where a hydraulic retention time is 30 min; (b) carrying out routine water treatment process, which includes coagulation processing, sedimentation processing and filtration processing. After the water treatment process, the removal rate of bisphenol A is above 98%.
Exemplary Embodiment 33
[0098] The water treatment agent for removing contaminants through oxidation with highly active manganese (V) intermediate according to this embodiment is composed of permanganate, citric acid as ligand and peroxomonosulfate, wherein a molar ratio of the permanganate and the ligand is 1:20 and a molar ratio of the permanganate and the peroxomonosulfate is 1:200, wherein the permanganate is potassium permanganate and/or sodium permanganate, wherein the peroxomonosulfate is MHSO 5 , where M is K, Na or NH 4 .
[0099] According to this exemplary embodiment, if the permanganate is a mixture of potassium permanganate and sodium permanganate, the ratio of different components in the mixture is not restricted.
[0100] According to this preferred embodiment of the present invention, a water treatment process which utilizes the water treatment agent for removing contaminants through oxidation with highly active manganese (V) intermediate in which the water subject to treatment contains 10 μmol/L bisphenol A comprises the following steps: (a) adding the water treatment agent according to this embodiment into the water subject to treatment which contains 10 μmol/L bisphenol A, and maintaining a concentration of permanganate at 5 μmol/L, a concentration of peroxomonosulfate at 1000 μmol/L and a concentration of citric acid at 100 μmol/L, where a hydraulic retention time is 30 min; (b) carrying out routine water treatment process, which includes coagulation processing, sedimentation processing and filtration processing. After the water treatment process, the removal rate of bisphenol A is above 98%.
Exemplary Embodiment 34
[0101] The water treatment agent for removing contaminants through oxidation with highly active manganese (V) intermediate according to this embodiment is composed of permanganate, phosphate as ligand and peroxomonosulfate, wherein a molar ratio of the permanganate and the ligand is 1:5 and a molar ratio of the permanganate and the peroxomonosulfate is 1:20, wherein the permanganate is potassium permanganate and/or sodium permanganate, wherein the peroxomonosulfate is MHSO 5 , where M is K, Na or NH 4 .
[0102] According to this exemplary embodiment, if the permanganate is a mixture of potassium permanganate and sodium permanganate, the ratio of different components in the mixture is not restricted.
[0103] According to this preferred embodiment of the present invention, a water treatment process which utilizes the water treatment agent for removing contaminants through oxidation with highly active manganese (V) intermediate in which the water subject to treatment contains 10 μmol/L phenol comprises the following steps: (a) adding the water treatment agent according to this embodiment into the water subject to treatment which contains 10 μmol/L phenol, and maintaining a concentration of permanganate at 50 μmol/L, a concentration of peroxomonosulfate at 1000 μmol/L and a concentration of phosphate at 250 μmol/L, where a hydraulic retention time is 180 min; (b) carrying out routine water treatment process, which includes coagulation processing, sedimentation processing and filtration processing. After the water treatment process, the removal rate of phenol is above 98%
Exemplary Embodiment 35
[0104] The water treatment agent for removing contaminants through oxidation with highly active manganese (V) intermediate according to this embodiment is composed of permanganate, pyrophosphate as ligand and peroxomonosulfate, wherein a molar ratio of the permanganate and the ligand is 1:5 and a molar ratio of the permanganate and the peroxomonosulfate is 1:20, wherein the permanganate is potassium permanganate and/or sodium permanganate, wherein the peroxomonosulfate is MHSO 5 , where M is K, Na or NH 4 .
[0105] According to this exemplary embodiment, if the permanganate is a mixture of potassium permanganate and sodium permanganate, the ratio of different components in the mixture is not restricted.
[0106] According to this preferred embodiment of the present invention, a water treatment process which utilizes the water treatment agent for removing contaminants through oxidation with highly active manganese (V) intermediate in which the water subject to treatment contains 5 μmol/L phenol comprises the following steps: (a) adding the water treatment agent according to this embodiment into the water subject to treatment which contains 5 μmol/L phenol, and maintaining a concentration of permanganate at 5 μmol/L, a concentration of peroxomonosulfate at 100 μmol/L and a concentration of pyrophosphate at 25 μmol/L, where a hydraulic retention time is 30 min; (b) carrying out routine water treatment process, which includes coagulation processing, sedimentation processing and filtration processing. After the water treatment process, the removal rate of phenol is above 98%.
Exemplary Embodiment 36
[0107] The water treatment agent for removing contaminants through oxidation with highly active manganese (V) intermediate according to this embodiment is composed of manganese dioxide, ethylenediaminetetraacetic acid (EDTA) as ligand and peroxomonosulfate, wherein a molar ratio of the manganese dioxide and the ligand is 1:10 and a molar ratio of the manganese dioxide and the peroxomonosulfate is 1:10, wherein the peroxomonosulfate is MHSO 5 , where M is K, Na or NH 4 .
[0108] According to this preferred embodiment of the present invention, in the presence of ethylenediaminetetraacetic acid (EDTA) as ligand, bivalent or trivalent manganese is produced through reaction between manganese dioxide and pollutants in the water subject to treatment, and the rapid and in situ reaction between the bivalent or the trivalent manganese and peroxomonosulfate can result in the production of highly active manganese (V) intermediate. The highly active manganese (V) intermediate produced from the in situ reaction has strong oxidizing activity which is capable of removing the organic pollutants in water at a faster rate while no toxic and harmful by-products are produced.
[0109] According to this preferred embodiment of the present invention, a water treatment process which utilizes the water treatment agent for removing contaminants through oxidation with highly active manganese (V) intermediate in which the water subject to treatment contains 5 μmol/L bisphenol A comprises the following steps: (a) adding the water treatment agent according to this embodiment into the water subject to treatment which contains 5 μmol/L bisphenol A, and maintaining a concentration of manganese dioxide at 60 μmol/L, a concentration of peroxomonosulfate at 600 μmol/L and a concentration of EDTA at 60 μmol/L, where a hydraulic retention time is 180 min; (b) carrying out routine water treatment process, which includes coagulation processing, sedimentation processing and filtration processing. After the water treatment process, the removal rate of bisphenol A is above 99%.
Exemplary Embodiment 37
[0110] The water treatment agent for removing contaminants through oxidation with highly active manganese (V) intermediate according to this embodiment is composed of manganese dioxide, hydroxy ethylidene diphosphonic acid as ligand and peroxomonosulfate, wherein a molar ratio of the manganese dioxide and the ligand is 1:5 and a molar ratio of the manganese dioxide and the peroxomonosulfate is 1:20, wherein the peroxomonosulfate is NaHSO 5 .
[0111] According to this preferred embodiment of the present invention, a water treatment process which utilizes the water treatment agent for removing contaminants through oxidation with highly active manganese (V) intermediate in which the water subject to treatment contains 10 μmol/L bisphenol A comprises the following steps: (a) adding the water treatment agent according to this embodiment into the water subject to treatment which contains 10 μmol/L bisphenol A, and maintaining a concentration of manganese dioxide at 60 μmol/L, a concentration of peroxomonosulfate at 1200 μmol/L and a concentration of hydroxy ethylidene diphosphonic acid at 600 μmol/L, where a hydraulic retention time is 180 min; (b) carrying out routine water treatment process, which includes coagulation processing, sedimentation processing and filtration processing. After the water treatment process, the removal rate of bisphenol A is above 99%.
Exemplary Embodiment 38
[0112] The water treatment agent for removing contaminants through oxidation with highly active manganese (V) intermediate according to this embodiment is composed of manganese dioxide, polyphosphates as ligand and peroxomonosulfate, wherein a molar ratio of the manganese dioxide and the ligand is 1:5 and a molar ratio of the manganese dioxide and the peroxomonosulfate is 1:50, wherein the peroxomonosulfate is NaHSO 5 .
[0113] According to this preferred embodiment of the present invention, the polyphosphates is potassium tripolyphosphate.
[0114] According to this preferred embodiment of the present invention, a water treatment process which utilizes the water treatment agent for removing contaminants through oxidation with highly active manganese (V) intermediate in which the water subject to treatment contains 10 μmol/L bisphenol A comprises the following steps: (a) adding the water treatment agent according to this embodiment into the water subject to treatment which contains 10 μmol/L bisphenol A, and maintaining a concentration of manganese dioxide at 60 μmol/L, a concentration of peroxomonosulfate at 3000 μmol/L and a concentration of polyphosphates at 300 μmol/L, where a hydraulic retention time is 180 min; (b) carrying out routine water treatment process, which includes coagulation processing, sedimentation processing and filtration processing. After the water treatment process, the removal rate of bisphenol A is above 99%.
Exemplary Embodiment 39
[0115] The water treatment agent for removing contaminants through oxidation with highly active manganese (V) intermediate according to this embodiment is composed of manganese dioxide, malonic acid as ligand and peroxomonosulfate, wherein a molar ratio of the manganese dioxide and the ligand is 1:20 and a molar ratio of the manganese dioxide and the peroxomonosulfate is 1:100, wherein the peroxomonosulfate is NaHSO 5 . According to this preferred embodiment of the present invention, a water treatment process which utilizes the water treatment agent for removing contaminants through oxidation with highly active manganese (V) intermediate in which the water subject to treatment contains 10 μmol/L bisphenol A comprises the following steps: (a) adding the water treatment agent according to this embodiment into the water subject to treatment which contains 10 μmol/L bisphenol A, and maintaining a concentration of manganese dioxide at 30 μmol/L, a concentration of peroxomonosulfate at 3000 μmol/L and a concentration of malonic acid at 600 μmol/L, where a hydraulic retention time is 180 min; (b) carrying out routine water treatment process, which includes coagulation processing, sedimentation processing and filtration processing. After the water treatment process, the removal rate of bisphenol A is above 99%.
Exemplary Embodiment 40
[0116] The water treatment agent for removing contaminants through oxidation with highly active manganese (V) intermediate according to this embodiment is composed of manganese dioxide, ethylenediaminetetrapropionic acid as ligand and peroxomonosulfate, wherein a molar ratio of the manganese dioxide and the ligand is 1:5 and a molar ratio of the manganese dioxide and the peroxomonosulfate is 1:500, wherein the peroxomonosulfate is NaHSO 5 .
[0117] According to this preferred embodiment of the present invention, a water treatment process which utilizes the water treatment agent for removing contaminants through oxidation with highly active manganese (V) intermediate in which the water subject to treatment contains 10 μmol/L bisphenol A comprises the following steps: (a) adding the water treatment agent according to this embodiment into the water subject to treatment which contains 10 μmol/L bisphenol A, and maintaining a concentration of manganese dioxide at 50 μmol/L, a concentration of peroxomonosulfate at 25000 μmol/L and a concentration of ethylenediaminetetrapropionic acid at 250 μmol/L, where a hydraulic retention time is 180 min; (b) carrying out routine water treatment process, which includes coagulation processing, sedimentation processing and filtration processing. After the water treatment process, the removal rate of bisphenol A is above 99%.
Exemplary Embodiment 41
[0118] The water treatment agent for removing contaminants through oxidation with highly active manganese (V) intermediate according to this embodiment is composed of manganese dioxide, oxalic acid as ligand and peroxomonosulfate, wherein a molar ratio of the manganese dioxide and the ligand is 1:40 and a molar ratio of the manganese dioxide and the peroxomonosulfate is 1:800, wherein the peroxomonosulfate is NaHSO 5 .
[0119] According to this preferred embodiment of the present invention, a water treatment process which utilizes the water treatment agent for removing contaminants through oxidation with highly active manganese (V) intermediate in which the water subject to treatment contains 10 μmol/L bisphenol A comprises the following steps: (a) adding the water treatment agent according to this embodiment into the water subject to treatment which contains 10 μmol/L bisphenol A, and maintaining a concentration of manganese dioxide at 5 μmol/L, a concentration of peroxomonosulfate at 4000 μmol/L and a concentration of oxalic acid at 200 μmol/L, where a hydraulic retention time is 180 min; (b) carrying out routine water treatment process, which includes coagulation processing, sedimentation processing and filtration processing. After the water treatment process, the removal rate of bisphenol A is above 99%.
Exemplary Embodiment 42
[0120] The water treatment agent for removing contaminants through oxidation with highly active manganese (V) intermediate according to this embodiment is composed of manganese dioxide, citric acid as ligand and peroxomonosulfate, wherein a molar ratio of the manganese dioxide and the ligand is 1:50 and a molar ratio of the manganese dioxide and the peroxomonosulfate is 1:1000, wherein the peroxomonosulfate is NaHSO 5 .
[0121] According to this preferred embodiment of the present invention, a water treatment process which utilizes the water treatment agent for removing contaminants through oxidation with highly active manganese (V) intermediate in which the water subject to treatment contains 10 μmol/L bisphenol A comprises the following steps: (a) adding the water treatment agent according to this embodiment into the water subject to treatment which contains 10 μmol/L bisphenol A, and maintaining a concentration of manganese dioxide at 5 μmol/L, a concentration of peroxomonosulfate at 5000 μmol/L and a concentration of citric acid at 250 μmol/L, where a hydraulic retention time is 180 min; (b) carrying out routine water treatment process, which includes coagulation processing, sedimentation processing and filtration processing. After the water treatment process, the removal rate of bisphenol A is above 99%.
[0122] One skilled in the art will understand that the embodiment of the present invention as shown in the drawings and described above is exemplary only and not intended to be limiting.
[0123] It will thus be seen that the objects of the present invention have been fully and effectively accomplished. It embodiments have been shown and described for the purposes of illustrating the functional and structural principles of the present invention and is subject to change without departure from such principles. Therefore, this invention includes all modifications encompassed within the spirit and scope of the following claims. | A water treatment agent for removing contaminants through oxidation with high-activity intermediate-state pentavalent manganese consists of a manganese-containing compound, a complexing agent, and a persulfate, wherein the manganese-containing compound is bivalent manganese ions, permanganate or manganese dioxide. The molar ratio of the bivalent manganese ions, the ligand, and the persulfate is 1:1-50:1-1000. The agent removes contaminants through oxidation with high-activity intermediate-state pentavalent manganese, and has the advantages of high oxidizing ability, being capable of fast removing organic contaminants in water, and having no toxic and harmful substance produced. | 2 |
CROSS-REFERENCE
[0001] This application is a continuation-in-part of U.S. application Ser. No. 09/937,187, a U.S. national phase application of international application number PCT/US00/13292 filed May 12, 2000, which in turn gains priority from U.S. provisional application, Ser. No. 60/134,286 filed May 14, 1999, all priority applications, hereby incorporated by reference.
BACKGROUND OF THE INVENTION
[0002] The fusion of peptides to the coat proteins of amplifiable genetic particles, e.g., phage, is a widely used method for screening combinatorial libraries of peptides (Rodi and Malowski, Curr. Opin. Biotechno., 10:87-93 (1999); Wilson and Finlay, Canadian Journal of Microbiology, 44:313-329 (1998)). One common approach is to express random sequences at the N-terminus of the bacteriophage M13 coat protein pIII, resulting in library complexities of up to 10 9 different clones. Selection is achieved by performing multiple rounds of target binding (panning), elution and amplification. Each round of panning enriches the pool of clones in favor of the tightest-binding ligands. Because each phage particle contains both the displayed peptide and the DNA encoding it, the selected peptides can be readily identified by DNA sequencing. Despite its utility and convenience, in vivo biological expression limits library diversity to combinations of twenty of the naturally occurring amino acids, linked by peptide bonds.
[0003] This problem can be partially circumvented by taking advantage of the enormous potential chemical diversity of synthetic combinatorial libraries. A vast body of work has been carried out with libraries consisting of systematic variations of peptides (Geysen, et al., Proc. Natl. Acad. Sci. USA, 81:3998-4002 (1984); Houghten, et al., Nature 354:84-86 (1991), Lam, et al., Nature, 354: 82-84 (1991)), peptide analogues (Figliozzi, et al., Methods Enzymol., 267:437-447 (1996), and small molecules (Bunin, et al., Methods Enzymol., 267:448-465 (1996), and an entire industry has been built around this type of combinatorial chemistry. While libraries well in excess of 10 18 different molecules (equivalent to 1 μmol of material if one molecule of each variant is present) can be synthesized, the identification of which molecules bind to a given target from such a vast pool is problematic. Libraries are typically synthesized in spatially addressable form, e.g., grids of pins or wells each containing one compound (Geysen, supra), or tethered to macromolecular beads containing a chemical tag which specifically identifies the attached compound (Lam, et al., supra). Ligand identification thus limits the size of chemically synthesized libraries to a practical upper limit of 10 4 -10 6 different molecules. Unlike biosynthetic libraries such as phage display peptide libraries, however, chemically synthesized libraries are not limited to a small subset of potential functional diversity.
[0004] The functional diversity of phage displayed peptide libraries can be increased by specifically chemically modifying the library prior to each round of panning. Phage libraries with enzymatically phosphorylated tyrosine residues have been constructed to map protein kinase and SH2 domain recognition sequences (Dente, et al., Journal of Molecular Biology, 269:694-703 (1997); Schmitz, et al., J. Mol. Biol., 260:664-677 (1996)). Phage libraries have also been biotinylated at specific lysine residues during in vivo phage morphogenesis, but this method requires a specific 66-residue biotinylation motif (Stolz, et al., FEBS Lett., 440:213-217 (1998)). Both of these methods require defined flanking sequence, and the incorporated modification cannot be altered. Therefore neither are generally applicable to incorporation of any desired chemical functionality in the context of a randomized amino acid sequence. For example, there are no methods for specifically modifying displayed tyrosine with other chemical moieties while protecting endogenous tyrosine residues elsewhere on the phage coat. The side chains of lysine and cysteine are reactive, but small-molecule reagents are likely to target residues within the native coat protein in addition to the displayed peptide. A new type of phage library, with a unique site available for a broad range of chemical modifications, is therefore needed.
[0005] To maintain the essential amplification and selection techniques of phage display, the existing bacterial genetic machinery should be employed to incorporate the unique reactive site into the displayed peptide. A method in which a non-native residue is incorporated into a phage-displayed protein by native chemical ligation (Dwyer, et al., Chem. Biol., 7:263-274 (2000)) could in principle be used to incorporate a unique reactive site, but this method requires that the non-native residue be incorporated within a synthetic peptide sequence, which is then chemically ligated onto a phage displayed polypeptide. As a result, the residues flanking the potential modification site are not encoded on the phage genome, severing the link between displayed sequence and DNA sequence.
SUMMARY OF THE INVENTION
[0006] In accordance with the present invention, the power of in vivo biomolecular amplification with the unlimited diversity of small molecule chemistry is united in selenopeptide phage display. The naturally-occurring amino acid selenocysteine (Sec) is incorporated uniquely and specifically in the context of a polypeptide displayed on the surface of an amplifiable genetic particle (phage, polysome, cell or spore) in response to incorporation signals engineered in the encoding DNA. In addition to conferring the unique activities of the selenol group to the chemistry of the displayed peptide, Sec also provides a unique handle for specific chemical modification of the displayed peptide. In addition to increasing the palette of available residues in a random peptide library to 21 possibilities, the present invention also provides a means of tethering virtually any desired chemical functionality to the incorporated Sec. Applications include, but are not limited to, pre-modifying a random peptide library with enzyme substrate analogs or inhibitors prior to panning for higher-affinity inhibitors, as well as selection/evolution of displayed enzyme specificity by catalytic selection using a substrate tethered to the same particle via an incorporated selenocysteine. Additionally, the coupling of Sec incorporation to phage plaque formation provides a rapid nonradioactive assay for DNA sequence requirements for efficient Sec incorporation.
[0007] In one embodiment of the invention, an amplifiable genetic particle is provided that includes a surface containing a protein to which a recombinantly expressed peptide is covalently linked. The covalent linkage may be a native peptide bond. Each peptide has a selenocysteine located at a specific and unique site, and may be expressed by a DNA having a TGA codon and a part or all of a selenocysteine insertion sequence. Additionally, the selenocysteine insertion sequence may begin one or more nucleotides from the TGA codon. The displayed selenocysteine residue may be flanked on either or both sides by one or more randomized amino acid. For example, randomized amino acid residues may be flanked by a cysteine residue on one side and a selenocysteine residue on the other side. In addition, the selenocysteine is capable of chemical derivatization of the selenol group. This chemical derivation may, for example, result from a nucleophilic substitution reaction, an oxidation reaction or a metal coordination reaction.
[0008] The product of chemical derivatization may be a chemical functionality selected from the group consisting of enzyme substrates, enzyme cofactors, enzyme inhibitors, receptor ligands and cytotoxic agents. The chemical functionality may be a known ligand for a target protein. In particular instances, the target protein may be an enzyme and the ligand an enzyme inhibitor or substrate. In particular, the recombinantly expressed protein containing a selenocysteine is fused to a ligand via the selenocysteine, the fused ligand having improved binding activity compared to the non-fused ligand.
[0009] The genetic particle according to the above may be selected from a phage, a polysome, a virus, a cell or a spore. The selenocysteine insertion sequence may be obtained from the group consisting of eubacteria, eukarya and archea.
[0010] In an additional example of the embodiment of the invention, the one or more peptides may include at least one peptide that forms an enzyme substrate or is modified at the selenocysteine to form an enzyme substrate, where the amplifiable genetic particle further includes a recombinantly expressed enzyme on the surface of the amplifiable genetic particle. In this example, the reaction product of the enzyme and the enzyme substrate may be located on the surface of the amplifiable genetic particle and capable of binding to an affinity substrate. The recombinantly expressed enzyme may be selected from a library of variants of a single enzyme, wherein each variant contains one or more amino acid substitutions relative to the native enzyme and/or from an expressed cDNA.
[0011] In an embodiment of the invention, a fusion protein is provided which contains a selenocysteine-containing peptide covalently linked to a surface protein positioned on an amplifiable particle where the amplifiable genetic particle may be one of: a phage, a polysome, a virus, a cell or a spore. The selenocysteine insertion sequence may be derived from eubacteria, eukarya and archea. The selenocysteine-containing peptide in the fusion protein may be a recombinant protein wherein the selenocysteine is located at a predetermined, unique site.
[0012] The linkage between the selenocysteine-containing peptide and the surface protein may be a native peptide bond. The fusion protein described above may include a peptide, which is expressed by a DNA having a TGA codon and a part or all of a selenocysteine insertion sequence. The selenocysteine insertion sequence may be located adjacent to one or more nucleotides from the TGA codon. The selenocysteine may be flanked on either or both sides by one or more randomized amino acid. For example, the selenocysteine in the peptide may be positioned adjacent to one side of one or more randomized amino acids, the one or more randomized amino acids being flanked on a second side by a cysteine.
[0013] The fusion protein may include a selenocysteine within the peptide, which is capable of chemical derivatization of the selenol group. For example, the chemical derivatization may result from a nucleophilic substitution reaction or from an oxidation reaction or from a metal coordination reaction.
[0014] The product of chemical derivatization of the selenocysteine in the peptide may be a chemical functionality selected from the group consisting of enzyme substrates, enzyme cofactors, enzyme inhibitors, receptor ligands and cytotoxic agents.
[0015] The selenocysteine-containing peptide may further comprise an enzyme substrate or be modified at the selenocysteine to form an enzyme substrate. The enzyme substrate may form a reaction product in the presence of an enzyme and the enzyme substrate may be located on the surface of the amplifiable genetic particle. The reaction product may be capable of binding to an affinity substrate.
[0016] Where the selenocysteine-containing peptide is a recombinant protein, the recombinant protein may be selected from a library of variants of a single enzyme, such that each variant contains one or more amino acid substitutions relative to the native enzyme or is an expressed c-DNA library.
[0017] In an embodiment of the invention, a fusion protein is provided which includes a recombinantly expressed protein containing one or more selenocysteines at a predetermined site in the protein, where the recombinantly expressed protein is fused to a known ligand for a target molecule. The target molecule may be an enzyme and the ligand an enzyme inhibitor or substrate. The recombinantly expressed protein fused to the ligand desirably has improved binding activity to the target protein compared to the non-fused ligand.
[0018] In an embodiment of the invention, a method of screening for peptide-ligand fusion molecules having improved binding to a target molecule compared to non-fused ligand is provided which includes the steps of: (a) reacting chemically derivatized selenocysteine residues in a random peptide library with a ligand to form a chemically modified peptide library, the chemically modified peptide library being displayed on the surface of an amplifiable particle; (b) allowing the chemically modified peptide library to bind to the target molecule, wherein the target molecule is immobilized before or after binding to the peptide library; (c) removing unbound particles; (d) eluting bound particles; and (e) identifying peptide-ligand fusion molecules from above with improved binding to the target molecules.
[0019] In the above method, the target protein may be an enzyme and the ligand an enzyme inhibitor.
[0020] In an embodiment of the invention, a method is provided for identifying required DNA sequence elements for incorporation of selenocysteine into peptides. The method includes the steps of: (a) fusing a selenocysteine expression cassette to a surface peptide of an amplifiable genetic particle, whereby expression of the surface peptide is dependent upon incorporating a selenocysteine residue; (b) forming a library of sequence variants of the selenocysteine expression cassette; and (c) selecting for particles which are genetically amplifiable.
[0021] In another embodiment of the invention, a method is provided for discovery of structurally constrained ligands for a target molecule comprising the following steps: (a) reacting a structurally constrained peptide library displayed on the surface of an amplifiable genetic particle, comprising one or more randomized amino acid residues flanked by a cysteine residue on one side and a selenocysteine residue on the other side, with a target molecule to form bound particles; (b) removing unbound particles; (c) eluting bound particles; and (d) identifying peptide sequence displayed on the eluted bound particles.
DESCRIPTION OF THE DRAWINGS
[0022] FIG. 1 —Biosynthetic pathway for cotranslational selenocysteine incorporation. Sel C, the opal codon-specific Sec tRNA, is first charged with serine. ATP-dependent SelD catalysis transforms environmental selenite to an activated Se-phosphate species. This species is utilized by SelA to displace the serine hydroxyl with a selenol moiety, forming a Sec-charged tRNA that recognizes the UGA opal codon. In the presence of GTP, the SelB elongation factor effects Sec translation by binding both the Sec-tRNA and the mRNA SECIS.
[0023] FIG. 2 —The E. coil formate dehydrogenase (fdh) SECIS, with permissible mutations as reported in Heider, et al., EMBO J., 11:3759-3766 (1992); Klug, et al., Proc. Natl. Acad. Sci. USA 94:6676-6681 (1997); Liu, et al., Nucleic Acids Res., 26:896-902 (1998).
[0024] FIG. 3 —N-terminal protein sequencing of the fusion of the fdh SECIS with the maltose binding protein. HPLC PTH analysis is displayed in subtractive mode. The expected sequence was SARVSecHGPSV.
[0025] FIG. 3A —Cycle 3 subtracted from cycle 4.
[0026] FIG. 3B —Cycle 4 subtracted from cycle 5.
[0027] FIG. 3C —Cycle 5 subtracted from cycle 6. S=serine; S′=dehydroalanine (expected acid breakdown product of Sec).
[0028] FIG. 4 —The randomized SECIS library inserts expressed as M13 pIII fusions. N=A, G, C or U. K=G or U. Permissible mutations are based on the E. coli formate dehydrogenase (fdh) SECIS as reported in Liu, et al., supra. The position immediately downstream from the UGA codon is fully randomized in the TGAN library, and is fixed as U in the TGAT library. (SEQ ID NO:1)
[0029] FIG. 5 —Plating results showing Se-dependent and -independent growth of phage clones TGAT-13, TGAT-10 and TGAN-8 (sequences in FIGS. 9 and 10 ). Left column: no supplemental Se in plating medium. Right column: 2 μM sodium selenite added to plating medium.
[0030] FIG. 6 —Clone TGAT-6 plaque count and size as a function of supplemental sodium selenite concentration in plating medium. Visible plaques were counted without magnification, and plaque diameter was measured under 7-fold magnification. Error bars represent ±1 standard deviation. Averages were based on triplicate platings, with ten plaques measured per plate.
[0031] FIG. 7 —Immunoblots of biotinylated phage, probed with HRP-conjugated anti-biotin antibody (NEB) and visualized by chemiluminescence. Phage (10 11 pfu) were diluted in 150 mM NaCl, 50 μM glycine-HCl (pH 2.5). Iodoacetyl-LC-Biotin (I-Bt) in DMF was added at 5% v/v to the indicated final concentration, and the reactions were incubated in the dark at room temperature. MW: biotinylated molecular weight markers.
[0032] FIG. 7A —Phage samples (peptide sequences in FIG. 9 ), treated with I-Bt for 30 min.
[0033] FIG. 7B —Sec-1 samples, treated with the indicated concentration of iodoacetamide for 1 h at room temperature, followed by 50 μM I-Bt for 20 min.
[0034] FIG. 8 —Immunoblots showing specific chemical modification of phage displaying selenopeptides. Individual library clones from the TGAN library (A) or TGAT library (B) were amplified with or without 2 μM supplemental sodium selenite as indicated. Phage were modified as described in Example III. *Amplification of clone TGAT-1 in unsupplemented medium resulted in a TGA→TGG point mutation.
[0035] FIG. 9 —Selected library TGAN clones. TGAN-1 was expressed as a pMal-pIII fusion, and tryptophan incorporation was verified by N-terminal sequencing. a op: opal suppression: Sec or W, depending on Se availability. b TGAN-7 production was Se-enhanced; Se supplementation yielded larger (3-4× diameter) and more (10×) plaques. (SEQ ID NO:2 through SEQ ID NO:14).
[0036] FIG. 10 —Selected TGAT library clones. TGAT-13 carried a T→C point mutation within the opal codon. (SEQ ID NO:15 through SEQ ID NO:27).
[0037] FIG. 11 —Schematic of selenosulfide-constrained heptapeptide library displayed as an N-terminal fusion to pIII of M13. The randomized sequence is flanked by an upstream cysteine (C) residue and a downstream selenocysteine (Sec) residue, which spontaneously oxidize to yield a redox-stable selenosulfide cross-link. Selenocysteine is encoded by the opal codon UAG with a SECIS immediately downstream. Each randomized residue is encoded by NNK, where N is an equimolar mixture of G, A, U, C; and K is equimolar U and G. (SEQ ID NO:40 and SEQ ID NO:41)
[0038] FIG. 12 —Phage ELISA showing binding of the indicated linear (Ser-Ser), disulfide constrained (Cys-Cys) and selenosulfide constrained (Cys-Sec) sequences to streptavidin, in the presence and absence of 10 mM dithiothreitol (DTT). Purified phage displaying the indicated constrained or unconstrained peptide sequence were added in the indicated amounts (pfu, plaque forming units). Following washing, bound phage were detected with anti-M13 antibody conjugated to horseradish peroxidase. Following development with ABTS/H 2 O 2 in citrate buffer, plates were read in an ELISA plate reader at 405 nm.
[0039] FIG. 13 : Phage ELISA data showing affinities of modified (solid lines) and unmodified (dashed lines) phage for MBP-BirA fusion.
DETAILED DESCRIPTION OF THE INVENTION
[0040] The present invention which describes a method for biosynthetic incorporation of a unique reactive site takes advantage of the naturally occurring amino acid selenocysteine (Sec). The potential modifications of Sec derive from its unique chemical properties. The pKa of Sec is 5.2, compared to 8.1 for Cys, so that at pH 6-7, nucleophilic substitution reactions can specifically alkylate Sec. but not Cys residues (Gorlatov and Stadtman, et al., Proc. Natl. Acad. Sci. USA 95:8520-8525 (1998)). The formation of stable sulfide-selenide cross-links (Pegoraro, et al., J. Mol. Biol. 284:779-792 (198)) also permits covalent Sec modification by thiol reagents.
[0041] The term “a” as used here and in the claims is not intended to be limited to one.
[0042] Where a target molecule is immobilized, immobilization may be achieved by attachment to beads, a gel, a column, a paper or other solid commonly used in the art to immobilize a molecule.
[0043] Incorporation of selenocysteine involves harnessing the existing biosynthetic mechanism. Eubacterial Selenocysteine (Sec) incorporation, as depicted in FIG. 1 , has been well characterized and requires the constitutively expressed selA, selB, selC and selD gene products (Böck, et al., Mol. Microbiol., 5:515-520 (1991)). Sec is encoded by the TGA opal stop codon (Zinoni, et al., Proc. Natl. Acad. Sci. USA 84:3156-3160 (1987)), which is suppressed in the presence of a specific downstream hairpin structure termed the Selenocysteine Insertion Sequence (SECIS). Sec is incorporated via a unique tRNA species, the selC gene product, which is initially aminoacylated with serine by seryl-tRNA synthetase. The loaded serine is converted to selenocysteine by the selA gene product, using a selenium phosphate donor synthesized by the selD gene product. Translation by the resulting Sec-tRNA Sec is mediated by the selB product, an analog of (the Elongation Factor EF-Tu which simultaneously recognizes Sec-tRNA Sec and the SECIS. The incorporation mechanism in Eukarya and Archaea is nearly identical (Stadtman, Ann. Rev. Biochem. 65:83-100 (1996)).
[0044] The mRNA requirements for E. coli Sec incorporation, summarized in FIG. 2 , indicate that the minimal SECIS consists of a short hairpin sequence with fixed nucleotides, located exactly 11 bases downstream from the UGA stop codon. Considerable nucleotide flexibility is allowed in this intervening sequence, permitting incorporation of selenocysteine within a randomized stretch of amino acids.
[0045] The present invention comprises three components:
(a) an expression system for display of heterologous peptide and protein sequences on the surface of amplifiable genetic particles (bacteriophage, virus, polysome, cells, spores, etc.) as fusions to surface proteins; (b) a UGA opal codon at the position in the displayed polypeptide where selenocysteine is to be incorporated; and (c) a minimal SECIS at the proper distance downstream from the UGA codon to direct Sec incorporation, incorporated so as not to interrupt the reading frame of the displayed polypeptide-surface protein fusion.
[0049] It is demonstrated in the Examples herein that selenopeptide libraries displayed on the surface of bacteriophage can be generated using an adaptation of standard phage display methods. The evidence for selenocysteine incorporation is described in Sandman, et al., J. Am. Chem. Soc., 122:960-961 (2000) and Sandman and Noren, Nucleic Acids Res. 28:755-761 (2000). Specifically, all of the TGAT library clones assumed to display exclusively selenopeptides formed plaques only in the presence of supplemental selenium. N-terminal sequencing of Maltose Binding Protein fusions revealed dehydroalanine, and not Trp, in several putative Sec-inserting clones. The chemical modification of the phage samples believed to contain Sec was consistent with selenium reactivity, with nucleophilic substitution readily occurring at acidic pH, where Cys is expected to be unreactive. Finally, the occurrence of clones encoding Cys proximal to the TGA codon also implicates Sec incorporation, since sulfide-selenide bridging would stabilize the otherwise unpaired Cys.
[0050] In accordance with the presentation, the molecular diversity of displayed peptides can now include twenty-one amino acids instead of the traditional twenty, but since the twenty-first amino acid can be specifically chemically modified, any desired functionality can be appended prior to each round of panning. Small libraries of appended functionalities may be screened by modifying the peptide libraries in separate and spatially addressable reaction vessels. Enzyme inhibitors may be identified by modifying Sec with substrate or transition state analogs and panning the resulting modified peptide libraries against enzymes. By tethering a known low-affinity inhibitor to a random peptide library, flanking residues which increase the overall affinity of the inhibitor-peptide chimera can be selected by standard phage panning methods. This concept of iterative ligand assembly has recently been demonstrated with small-molecule libraries (Maly, et al., Proc. Natl. Acad. Sci. USA, 97:2419-2424 (2000)), but the present invention extends this idea to take advantage of the vastly higher-complexity libraries allowed by surface display methods. The linkage of cytotoxic agents to the Sec residue, for example, may facilitate the discovery of peptide-drug complexes that are taken up into specific cell types. Particles simultaneously displaying enzyme libraries and substrate-derivatized selenopeptides may be screened for enzymes with enhanced activity or altered specificity. The covalent linkage of substrates to displayed peptides permits the rigorous reaction and selection conditions that might otherwise disrupt the noncovalent interactions utilized in recent examples of phage-mediated enzyme evolution. (Demartis, et al., J. Mol. Biol., 286:617-633 (1999); Pedersen, et al., Proc. Natl. Acad. Sci, USA 95:10523-10528 (1998)).
[0051] The present invention also provides a useful tool for further study of the requirements for selenocysteine incorporation. By coupling plaque formation to selenocysteine incorporation it is possible to screen thousands of sequences at once, using a simple, nonradioactive visual readout that specifically indicates Sec incorporation rather than general opal suppression. Previous studies of prokaryotic SECIS requirements suggested that certain elements of the mRNA structure were essential, whereas others could be changed without affecting opal codon readthrough (Liu, et al., supra). In accordance with the methods of the present invention, it was rapidly determined that the first nucleotide downstream of TGA strongly influences opal suppression in E. coli, with purines or CTG promoting a dual-pathway approach in which Trp insertion is always possible, and Sec insertion occurs if Se is available. TGA-pyrimidine sequences, on the other hand, only permit the inefficient cotranslational Sec insertion pathway, thereby occasionally allowing opal codon mutants to dominate a culture. The apparent stabilization of unpaired Cys residues by Sec overrides these rules, so that an adjacent unpaired Cys will strongly favor the Sec insertion pathway, regardless of the downstream nucleotide. This application has important implications for heterologous expression of mammalian selenoproteins in prokaryotic systems (Arner, et al., J. Mol. Biol. 292:1003-1016 (1999)): the present invention can be used to optimize the expression level of virtually any selenoprotein.
[0052] Present embodiments of the invention are further illustrated by the following Examples. These Examples are provided to aid in the understanding of the invention and are not construed to be a limitation thereof.
[0053] The references cited above and below are herein incorporated by reference.
EXAMPLE I
Expression of Native E. Coli fdh Sequences as M13 pIII Fusion
[0054] As a control, the native E. coli formate dehydrogenase (fdh) SECIS ( FIG. 2 , amino acid sequence Ser-Ala-Arg-Val-Sec-His-Gly-Pro (SEQ ID NO:28)) was cloned into M13KE, an M13mp19 derivative designed with Acc65I and EagI sites for pentavalent N-terminal pIII expression (Zwick, et al., Analytical Biochemistry, 264:87-97 (1998)). The following oligonucleotides were synthesized by the phosphoramidite method by the Organic Synthesis Division of New England Biolabs, Inc. (Beverly, Mass.). Acc65I and EagI restriction sites are indicated in bold.
[0055] fdh SECIS control oligonucleotide:
5′-CATGTTT CGGCCG TACCGACCGATTGGTGCAGACCTGCAACC (SEQ ID NO:29) GATGGGCCGTGTCAGACACGAGCGCTAGAGTGAGAATAGAAA GGT ACC CGGGCATG-3′
[0056] Duplex extension primer (New England Biolabs, (Beverly, Mass.) product #8101):
5′-CATGCCCG GGTACC TTTCTATTCTC-3′ (SEQ ID NO:30)
[0057] The fdh SECIS control oligonucleotide was synthesized, gel-purified, and annealed to the duplex extension primer. The duplex was extended with dNTPs and Klenow fragment, digested with Acc65I and EagI, gel-purified and ligated into Acc65I/EagI digested phage cloning vector M13KE. The ligation products were electroporated into E. coli ER2537 (F′lacI q Δ(lacZ)M15 proA + B + /fhuA2 supE thiΔ(lac-proAB)Δ(hsdMS-mcrB)5 and plated with 100 μL of a late log-phase ER2537 culture in 3 mL of agarose top on LB agar plates with 210 μM IPTG and 98 μM Xgal. The agarose top contained 10 g/L tryptone (Difco, Detroit, Mich.), 5 g/L yeast extract (Difco, Detroit, Mich.), 86 mM sodium chloride, 5 mM magnesium chloride, and 7 g/L agarose (American Bioanalytical, Natick, Mass.) supplemented with 2 μM sodium selenite. The M13KE vector carries the lacZα fragment, resulting in characteristic blue plaques when plated with an α-complementing strain on X-gal medium. After a 16 h 37° C. incubation, blue plaques were selected and the individual clones were amplified in early log-phase cultures of ER2537 supplemented with 2 μM sodium selenite. Sequencing templates were prepared by ethanol precipitation of phage DNA from 4 M sodium iodide (Wilson, Biotechniques 15:414-416, 418-420, and 420 (1993)). Phage clones were stored at 4° C. in a 150 mM Tris pH 7.4, 50 mM sodium chloride, 100 μM DTT buffer with 0.02% sodium azide. Automated DNA sequencing was performed on a PE-ABD 377 or 373 instrument using Dye-Deoxy™ terminator chemistry (PE Applied Biosystems, Foster City, Calif.) with the -96 gIII sequencing primer (New England Biolabs, Inc. (Beverly, Mass.) product #1259, 5′-CCCTCATAGTTAGCGTA ACG-3′ (SEQ ID NO:31)), and yielded the expected sequence (designated Sec-1).
[0058] pMal-pIII Fusion Protein Expression.
[0059] In order to obtain sufficient quantity of material for confirmation of Sec incorporation by N-terminal protein sequencing, the pMal-pIII shuttle vector (Zwick, et al., supra) was employed to overexpress and purify the Sec-1 peptide sequence as a fusion to the N-terminus of maltose binding protein (MBP). The resulting construct contains a pIII leader sequence to direct the fusion to the periplasm, resulting in the N-terminus of the MBP fusion being identical to that of the phage-displayed fdh sequence. The digested and gel-purified fdh SECIS insert was ligated into Acc65I/EagI digested pMal-pIII protein expression vector. The ligation products were electroporated into ER2537, plated on LB with 100 μg/mL ampicillin, and analyzed by restriction mapping and automated DNA sequencing. The pMal-pIII fusion proteins were expressed in ER2537 and purified as previously described (Zwick, et al., supra). For N-terminal protein sequencing, proteins were subjected to electrophoresis and electroblotted according to the procedure of Matsudaira (Matsudaira, J. Biol. Chem., 262:10035-10038 (1987)), with modifications as previously described (Looney, et al., Gene 80:193-208 (1989); Waite-Rees, et al., J. Bacteriol. 173:5207-5219 (1991)). The membrane was stained with Coomassie blue R-250 and the protein band of approximately 46 kDa was excised and subjected to sequential Edman degradation on a PE-Biosystems (Foster City, Calif.) 494A Protein/Peptide Sequencer using standard gas-phase cycles (Waite-Rees, supra). The results ( FIG. 3 ) showed the expected Sec-1 N-terminus, SARVXHGPSV (SEQ ID NO:32), with X assumed to be Sec. The acid breakdown product of a Sec residue, generated by acid-catalyzed β-elimination, should be the same as Cys or Ser residues in that all produce dehydroalanine (S′). The DTT adduct of the dehydroalanine PTH was observed at the position corresponding to the TGA codon (cycle 5). Ser also produces this adduct, but cycles 1 and 9, and not cycle 5, also showed a parent Ser peak. No significant amount of Trp-PTH (<200 fmol) was observed in this cycle, eliminating the possibility of endogenous Trp-inserting opal suppression.
EXAMPLE II
Construction and Characterization of TGAN and TGAT Libraries
[0060] Based on the reported minimal SECIS requirements ( FIG. 2 ) (Liu, et al., supra), a library consisting of the SECIS element with four upstream and three downstream randomized codons, and a minimal mRNA SECIS (TGAN library, FIG. 4 ), was prepared using the same cloning strategy described in Example I. The TGAN library oligo sequence was as follows, with Acc65I and EagI restriction sites in bold; M=A or C; N=A, C, T or G.
5′-CATGTTT CGGCCG ATTGGTGCAGACCTGCAACCGAMNNMNNM (SEQ ID NO:33) NNTCAMNNMNNMNNMNNAGAGTGAGAATAGAAA GGTACC CGGG- 3′
[0061] After duplex extension and restriction digestion, the resulting insert was ligated into M13KE, an M13mp19 derivative designed with Acc65I and EagI sites for pentavalent N-terminal pIII expression (Zwick, et al., supra). This vector also carries the lacZa fragment, resulting in characteristic blue plaques when plated with an α-complementing strain on X-gal medium. The sequences of selected clones are shown in FIG. 9 . Although the immediate downstream nucleotide was fully randomized in the TGAN library insert, the majority (74%) of the resulting phage clones possessed a downstream purine. One-third of the displayed peptides in the TGAN library possessed an unpaired Cys residue, which corresponds to 4.8% of the total randomized amino acids. Based on random codon usage, the calculated expected frequency for Cys is 3.1%, whereas the typically observed Cys frequency using this phage display system is less than 0.5%. Because M13 proteins are exported to the periplasm, the pairing of the eight Cys residues in M13 pIII into four disulfide bonds (Holliger and Riechmann, Structure 5:265-275 (1997)) could be disrupted by a single unpaired Cys within the displayed peptide. This phenomenon would likely not be observed with a cytoplasmically-expressed peptide library.
[0062] A second library (TGAT library, FIG. 4 ) was also constructed in which the nucleotide immediately downstream from the UGA codon was fixed as U (T in the DNA) in order to prevent endogenous tryptophan-inserting opal suppression, which is enhanced by downstream purines and the trinucleotide CUG (Miller and Albertini, J. Mol. Biol. 164:59-71 (1983)). The TGAT library was constructed as described above using the library oligonucleotide 5′-5′-CATGTTTCGGCC GATTGGTGCAGACCTGCMCCGAMNNMNNMNATCAMNNMNNMNN MNNAGAGTGAGAATAGAAAGGTACCCGGG-3′ (SEQ ID NO:34), where the EagI and Acc65I sites are indicated in bold (M=A or C; N=A, C, T or G). The electroporation and plating of the library ligation products resulted in small plaques, with about ten times more plaques forming in the presence of 2 μM supplemental sodium selenite as compared to unsupplemented medium. Individual plaques were amplified for further analysis, with representative sequences shown in FIG. 10 . The growth of all of the TGA-containing clones was strictly selenium-dependent, with plaques appearing only in the presence of 1-2 μM supplemental sodium selenite. M13KE phage growth, by contrast, was selenium-independent over a range of 0-4.5 μM supplemental sodium selenite. As with the TGAN library, single Cys residues occurred in the TGAT library at a higher than normal frequency of 4.3% of all random amino acids. The TGAT library also had occasional (<10% frequency) mutations within the opal codon, such as the point mutation in clone TGAT-13 ( FIG. 10 ), which converted the TGA opal codon to the CGA Arg codon.
[0063] Selenium Dependency of Phage Growth.
[0064] To assess the selenium dependency of phage production, phage samples were plated in media with or without 2 μM supplemental sodium selenite. Individual phage clones were diluted in LB and combined with 200 μL of a late log-phase ER2537 or ER2738 culture. After a 5 min incubation at room temperature, the bacteria and phage were combined with 3 mL of agarose top, with or without supplemental 2 μM sodium selenite, and plated on LB agar plates with IPTG and Xgal. After a 16 h 37° C. incubation the plates were inspected for the presence of blue plaques. Typical results are illustrated in FIG. 5 and summarized in the third column of FIG. 9 and FIG. 10 . Selenium-independent phage clones, such as TGAT-13 and TGAN-8, produced plaques of equal count and size regardless of the media selenium concentration. In contrast, clone TGAT-10 and other Se-dependent phage only produced plaques in Se-supplemented medium. To further quantitate the strict selenium dependence of phage growth, Clone TGAT-6 (ASPTSecFKP) was plated with varying concentrations of supplemental sodium selenite in the medium. FIG. 6 shows that the number and diameter of visible Clone 6 plaques increased in a selenium-dependent fashion from 0-3.2 μM sodium selenite, with half-maximal plaque diameter at ˜0.4 μM selenite.
[0065] All of the clones with an immediate downstream purine grew in a Se-independent manner, with the exception of those containing a single Cys codon within the displayed peptide sequence, e.g., TGAN-7, FIG. 9 . All of the clones with an opal codon immediately followed by a pyrimidine grew in a Se-dependent manner, with the exception of clone TGAN-10, which had a downstream CTG codon. All of the clones with mutated opal codons, such as TGAT-13, were Se-independent, as was M13KE phage without insert.
[0066] N-terminal Sequencing.
[0067] To further analyze the displayed peptides, the pMal-pIII shuttle vector was employed (Zwick, et al., supra). This vector allows inserts from M13KE to be expressed as fusions to the N-terminus of maltose binding protein (MBP), with a pIII leader sequence to direct the fusions to the periplasm. The TGAN-1 peptide, in which the UGA codon is followed by an A, was overexpressed and purified using this system. N-terminal sequencing revealed mostly (>90%) Trp incorporation at the TGA site, as expected from endogenous Trp-inserting opal suppression favored in this sequence context (Miller and Albertini, supra). This is fully consistent with the observed selenium independence of this clone. By contrast, the results of sequencing an MBP fusion with the selenium-dependent clone TGAT-12 were comparable to data obtained with the Sec-1 E. coli fdh SECIS insert ( FIG. 3 ), consistent with Sec and not Trp insertion.
EXAMPLE III
Chemical Modification of Selenopeptide Libraries
[0068] To rule out the possibility of Cys incorporation at the TGA codon, and to demonstrate specific chemical modification of the Sec residue in a displayed peptide, the chemical reactivity of the fdh control phage clone Sec-1 (SARV-Sec-HGP) was compared to that of clone Cys-1 (SARVLCNH (SEQ ID NO:35)), which contains a single unpaired cysteine residue. Phage samples were treated with iodoacetyl-LC-biotin (I-Bt, Pierce), an electrophilic reagent which should specifically target thiol or selenol groups with the enzyme cofactor biotin. Phage (10 10 pfu) in 150 mM sodium chloride, 50 mM glycine-HCl (pH 2.5) were combined with 50 μM iodoacetyl-LC-biotin in dimethylformamide (5% v/v) and incubated in the dark at room temperature for 10 min. The reactions were quenched by the addition of SDS gel loading buffer with 42 mM DTT, and samples were promptly denatured at 100° C. for 5 min and loaded on a 10-20% SDS-polyacrylamide gel. Immunoblotting was performed according to standard procedures, and the blots were probed with HRP-conjugated anti-biotin antibody (1:1000 dilution) or a mouse monoclonal anti-pIII antibody (Bio 101; 1:500 dilution) followed by an HRP-conjugated anti-mouse antibody. The blots were developed using the Phototope® Chemiluminescence kit (New England Biolabs, Inc., Beverly, Mass.).
[0069] FIG. 7A shows the results of immunoblotting of the products. At both pH 2.5 and pH 8, the biotinylation was highly specific for the Sec residue. Biotinylation of Cys-1 was enhanced at pH 8, although the reaction remained highly selective (>10:1) for Sec. The biotinylation experiments confirm that, at acidic pH, the reactivity of a Sec residue in a pIII fusion greatly exceeds that of the eight paired Cys residues (Holliger and Riechmann, supra) in M13 pIII or of an unpaired Cys residue in the displayed peptide.
[0070] Presumably because of the stability of sulfide-selenide cross-links, the selenopeptide library contained clones with a single Cys residue at a much higher incidence than is normally seen in pIII libraries constructed in the M13KE system. To determine whether the putative sulfide-selenide bridging inhibited Sec reactivity, phage clones TGAT-2 and TGAT-3 were modified with I-Bt; immunoblotting revealed that both samples were biotinylated to a similar extent as Sec-1 ( FIG. 7A ). This result suggests that the sulfide-selenide cross-link is sufficiently reversible to allow trapping of the free selenide with an excess of electrophile.
[0071] To estimate the efficiency of chemical modification, Sec-1 phage was modified with iodoacetamide (I-Ac), and the remaining unmodified phage was then reacted with I-Bt and detected by immunoblotting ( FIG. 7B ). Treatment for 1 h with 250 μM I-Ac at pH 2.5 was sufficient to block the biotinylation reaction. Because the electrophilicities of I-Ac and I-Bt are essentially identical, this result suggests that modification with I-Bt under these conditions would go to completion. To assess the infectivity of the modified phage, the Sec-1 clone was treated for 1 h at room temperature at pH 5.2 with I-Ac or I-Bt. After quenching with two equivalents of β-mercaptoethanol to scavenge any unreacted I-X electrophile, the samples were diluted and plated, with no significant effect on the resulting plaque counts.
EXAMPLE IV
Identification of SECIS Requirements
[0072] The mRNA requirements for E. coli Sec incorporation were previously determined by cloning the E. coil formate dehydrogenase gene (fdh) with non-native SECIS variants upstream of a β-galactosidase reporter gene, and then measuring either 75 Se incorporation by SDS-PAGE or β-galactosidase expression by a calorimetric assay (Chen, et al., J. Biological Chemistry, 268:23128-23131 (1993); Heider, et al., EMBO J., 11:3759-3766 (1992); Liu, et al., supra; Zinoni, et al., Proc. Natl. Acad. Sci. USA 84:3156-3160 (1990). Although reporter gene expression is the more quantitative of the two approaches, it is a measure of TGA suppression but not necessarily Sec incorporation. Many E. coil strains possess endogenous opal suppression activity resulting in tryptophan (Trp) incorporation (Miller and Albertini, supra), suggesting that a portion of the reporter gene expression could have been independent of Sec incorporation.
[0073] The coupled phage display assay which comprises the present invention was utilized to further investigate the E. Coli SECIS requirements (Sandman and Noren, supra). The native M13 proteins do not contain Sec (Ebright, et al., Gene 114:81-83 (1992); van Wezenbeek and Schoenmakers, supra), and M13 phage infectivity requires expression of the coat protein pIII (Holliger and Riechmann, supra). The fusion of putative selenopeptides to the N-terminus of pIII therefore should couple phage plaque formation to opal suppression. Because of the relatively high level of protein synthesis required for plaque formation, it was anticipated that selenium-supplemented media would be required for selenopeptide phage display. Putative selenopeptide-pIII fusions could thus be identified based on the selenium dependence of plaque formation, and this in vivo method could be used to identify critical SECIS elements from phage libraries. The utility of in vitro combinatorial methods was previously shown when RNA aptamer libraries were screened for SelB binding (Klug, et al., supra). The SECIS U 17 bulge, noted in FIG. 2 , was found to be required for SelB binding, which in turn is necessary for Sec incorporation. Whereas the aptamer method only revealed in vitro binding events, the phage display method provides a direct readout of prokaryotic Sec incorporation requirements in vivo.
[0074] In addition to selenium dependency of phage formation, Sec incorporation can also be assessed by modifying phage samples with readily detectable reagents as described in Example III. The pKa of Sec is 5.2, compared to 8.1 for cysteine (Cys), so that at pH 6-7, nucleophilic substitution reactions can specifically alkylate a Sec residue without modifying neighboring Cys residues (Gorlatov and Stadtman, supra). Example III describes a method to assay phage for selenopeptide display by treatment with an electrophilic iodoacetamido-biotin reagent, followed by detection of biotinylated phage with an anti-biotin antibody. Because the reactivity of Sec is unique from that of any other naturally occurring amino acid side chain, chemical reactivity is a more specific indicator of Sec than opal suppression.
[0075] Effect of Media Selenite on Selenocysteine Incorporation.
[0076] To explore the effect of sequence context on opal suppression, individual phage clones were amplified in media with or without supplemental 2 μM selenite. The resulting phage was quantitated by plating diluted samples, and the phage DNA was sequenced. As a test of Sec incorporation in the displayed peptides, phage clones were treated with iodoacetyl-LC-biotin (I-Bt) as in Example III, and the level of biotinylation was assessed by immunoblotting. As controls, M13KE phage and clones displaying a single unpaired Cys (Cys-1, displayed peptide SARVLCNH (SEQ ID NO:35) or Sec (Sec-1, displayed peptide SARVSecHGP, corresponding to the E. coli fdh SECIS) were used.
[0077] Clones TGAN-12 and TGAN-8, both of which had a downstream purine, produced equivalent levels of phage in supplemented and unsupplemented media. Growth of both clones in media with selenite substantially enhanced the reactivity of the resulting phage ( FIG. 8A ). Production of TGAN-7, which had a downstream purine and a single Cys, was enhanced 50-fold by supplemental Se. Clones with a downstream pyrimidine and a single Cys in the displayed peptide, such as TGAT-7 and TGAT-2, produced 1000-fold less phage without supplemental Se. The phage produced with supplemental Se from these clones had reactivity equal to that of the control Sec-1 phage ( FIG. 8B ). Clones such as TGAT-1, which possessed a downstream pyrimidine and no Cys in the displayed peptide, either had very low phage production in the absence of supplemental Se, or produced phage with opal codon mutations. FIG. 8B shows that clone TGAT-1 was reactive when amplified with Se; the TGA→TGG mutant resulting from amplification without Se was unreactive. Occasionally, TGAT clones also developed opal codon point mutations during amplification with supplemental Se.
[0078] The expression of randomized SECIS elements as N-terminal fusions to M13 pIII couples phage production to opal suppression, providing a combinatorial approach to understanding cotranslational Sec insertion. If a sequence fails to produce phage, then it is assumed that there is no opal suppression. If phage is produced in a Se-dependent manner, the opal suppression is presumed to be Sec-inserting. Se-independent phage production can result from Trp insertion or from mutations within the opal codon.
[0079] In addition to the principal requirement for Sec incorporation, the opal codon with a downstream SECIS, the invention demonstrates that the presence of a single Cys residue within a peptide displayed on M13 pIII is an important factor in Sec insertion. The occurrence of single Cys residues in selenopeptides was over 4%, higher than both the normally observed (<0.5%) and predicted (3.1%) frequencies for similar displayed peptide libraries. Moreover, library clones containing a single Cys residue possessed opal codon mutations with <1% frequency compared to almost 10% for the entire TGAT library. These effects presumably resulted from seleno-sulfide cross-linking, which would stabilize both the Cys and Sec residues in the M13 display system, where the coat protein pIII folds in the periplasm. Because it was possible to obtain and amplify many stable library clones containing an unpaired Sec but not a Cys, it appears that single Sec residues are somewhat more stable than unpaired Cys residues.
[0080] Among sequences that did not contain a single Cys residue, the nucleotide immediately downstream was a critical factor in determining whether Sec or Trp insertion occurred. The TGA-purine clones replicated with comparable phage yield and sequence fidelity regardless of the media Se concentration, suggesting that Sec insertion was not the major pathway. Purines in the first downstream position have previously been shown to enhance Trp-inserting opal suppression by endogenous tRNA TrP (Miller and Albertini, supra). Notably, the TGA CTG sequence present in the Se-independent clone TGAN-10 has also been shown to strongly promote Trp insertion (Miller and Albertini, supra). It was recently demonstrated that a downstream SECIS element enhanced opal suppression, presumably by Trp, even in the absence of functional SelB or SelC, possibly by interfering with RF2-dependent termination or by stabilizing the message (Suppmann, et al., EMBO J., 18:2284-2293 (1999)). Although the combination of the immediate downstream purine/CTG and the mRNA SECIS appeared to drive the Trp insertion pathway, it did not prohibit Sec insertion. Amplification of the TGA-purine clones in Se-supplemented media permitted Sec insertion, with phage reactivity comparable to that of fully Se-dependent clones.
[0081] Clones with an immediate downstream pyrimidine, except for CTG (TGAN-10), appeared to utilize primarily the Sec insertion opal suppression pathway; they required supplemental Se in order to produce functional phage, which was reactive with I-Bt. No other opal suppression pathway was implicated, since amplification in unsupplemented media resulted in either very low phage production or opal codon mutations. The occasional tendency of these clones to acquire opal mutations during Se-supplemented amplification was consistent with the recent finding that E. coli Sec insertion is only about 5% efficient (Suppmann, et al., supra). A spontaneous mutation in the opal codon would result in more efficient phage production, so that mutants would rapidly dominate the log-phase bacterial culture.
[0082] It has been shown (Poole, et al., EMBO J. 14:151-158 (1995)) that the nucleotide immediately downstream of the opal codon influences translational termination efficiency in E. coli, with an overall order of U>G>A>C. It was proposed that the recoding event of Sec insertion is favorable at the UGAC in E. coli fdh because RF2 binding is unfavorable in this context. The present data demonstrates that any nucleotide in the downstream position is capable of directing Sec insertion, and indeed, UGAU and UGAC are equally proficient. This suggests that the pathway leading to Sec insertion is independent of any effect of the immediate downstream nucleotide on RF2 binding.
[0083] All of the factors discussed above contribute to the observed preference for immediate downstream purines in the TGAN library. The downstream purine, followed by a SECIS, permitted maximal utilization of the endogenous opal suppression pathway without preventing cotranslational Sec insertion. This dual-pathway strategy effectively maximizes phage production. The fixed downstream pyrimidine (TGAT) library clones strongly favor the Sec insertion pathway, presumably resulting in more homogeneous displayed peptides. The cost of this homogeneity, however, is the likelihood of selection for adventitious mutations. These issues should be considered in cloning strategies for the bacterial expression of Sec-containing peptides and proteins.
EXAMPLE V
A Selenosulfide-constrained Peptide Library
[0084] Disulfide-constrained peptide libraries have been widely used for the discovery of high-affinity ligands for a number of targets (Giebel, et al., Biochemistry, 34:15430-15435 (1995); McLafferty, et al., Gene 128:29-36 (1993); O'Neil, et al., Proteins 14:509-515 (1992)). Flanking the randomized sequence with cysteine residues results in spontaneous oxidation of the thiol groups in aqueous buffer to form a disulfide crosslink. This results in the display of each peptide in the library as a disulfide-constrained loop, improving the free energy of binding by lowering the unfavorable entropic change associated with binding a free peptide to a target. Additionally, libraries of this type have proven useful in the identification of structural epitopes for antibodies (Luzzago, et al., Gene 128:51-57 (1993), and mimotopes (McConnell, et al., Gene 151:115-118 (1994)).
[0085] A drawback of disulfide-constrained libraries is that the disulfide crosslink is not stable under mildly reducing conditions, as are required by redox-sensitive protein targets such as bacterial cytoplasmic proteins. Under conditions where these targets would be expected to be stable, e.g., 10 mM dithiothreitol (DTT), a cysteine flanked peptide library would be linear and unstructured, rather than constrained. A solution to this problem is to replace one of the cysteines with selenocysteine (Sec), resulting in a spontaneous selenosulfide (Se-S) crosslink which would be stable under mildly reducing conditions. Using the present invention as embodied in Examples I-III described herein, a Sec encoding UAG opal codon, with an appropriately spaced SECIS element, can be incorporated on one side of a randomized segment of codons. A cysteine codon (UGU or UGC) is introduced on the other side, resulting the in the randomized segment being structurally constrained by a redox-stable selenosulfide crosslink ( FIG. 11 ).
[0086] As a demonstration of this technique a known ligand-target pair was chosen in which a disulfide constraint was previously shown to enhance binding of the ligand to the target. By flanking the ligand sequence with a pair of cysteines, or cysteine and selenocysteine, it was expected that both would bind the target well under nonreducing conditions, but only the selenosulfide-constrained sequence would bind well under reducing conditions. The ligand-target pair chosen was the sequence Cys-HPQGPP-Cys, (SEQ ID NO:36) which was demonstrated to bind streptavidin with 65-fold higher affinity than the linear sequence Ser-HPQGPP-Ser (SEQ ID NO:36) (Giebel, et al., supra).
[0087] The following oligonucleotides were synthesized, purified, annealed, extended and ligated into M13KE as described in Example I (Eag I and Acc65 I sites underlined):
Ser-Ser: 5′-GATGTTT CGGCCG ATTGATGAAGCCCAGCCACGC (SEQ ID NO:37) TTGGGCCGTGGCTCGGTGGACCTTGCGGATGGCTTTC CGCAGAGTGAGAATAGAAA GGTACC CGGG-3′ Cys-Cys: 5′-CATGTTTCGGCCGATTGATGAAGCCCAGCCACGC (SEQ ID NO:38) TTGGGCCGTGGCACGGTGGACCTTGCGGATGGCATTC CGCAGAGTGAGAATAGAAA GGTACC CGGG-3′ Cys-Sec: 5′-CATGTTTCGGCCGATTGGTGCAGACCTGCAACCG (SEQ ID NO:39) ATGGGCCGTGTCACGGTGGACCTTGCGGATGGCATTC CGCAGAGTGAGAATAGAAA GGTACC CGGG-3′
[0088] All three inserts encode the same sequence HPQGPP (SEQ ID NO:36), but flanked by Ser-Ser, Cys-Cys and Cys-Sec as indicated. The Cys-Sec insert has the E. coli fdh SECIS immediately downstream of the UGA opal codon, while the other inserts have the same amino acid sequence encoded by the SECIS but a different nucleotide sequence, abolishing any selenocysteine-directing activity. To enhance selenocysteine incorporation, media contained 2 μM sodium selenite in all plating and amplification steps for the Cys-Sec construct, but not the others.
[0089] Following electroporation into E. coli ER2738, plaques were picked and amplified in 20 ml early-log cultures of ER2738 for 5 hours at 37° C. Cells were removed by centrifugation and phage recovered from the supernatant by overnight precipitation with 1/6 volume 20% polyethylene glycol 8000 in 2.5 M NaCl at 4° C. Following centrifugation and reprecipitation, phage were suspended in 100 μl Tris-buffered saline (TBS), pH 8 and titered for plaque forming units. DNA sequencing indicated that the phage were displaying the correct sequences, with the exception of the Cys-Sec phage, which carried a point mutation which resulted in the displayed sequence being Cys-HPQGPT-Sec (SEQ ID NO:42), rather than Cys-HPQGPP-Sec.
[0090] Binding to streptavidin was assayed by enzyme-linked immunosorbant assay (ELISA), using diluted phage as the primary detection and anti-M13 antibody as secondary. Polystyrene plates were coated overnight with streptavidin (Prozyme, San Leandro, Calif.) at a concentration of 100 μg/ml in 0.1 M bicarbonate buffer, pH 8.6. Plates were blocked with 1 mg/ml bovine serum albumen in TBS and washed with TBS containing 0.05% Tween-20 (TBST). Phage were diluted in TBS either containing 10 mM dithiothreitol (DTr) or not containing DTT, and applied to the blocked, streptavidin-coated wells. After a 2 h incubation at 20° C., plates were washed extensively with TBST and bound phage were detected with anti-M13 antibody conjugated to horseradish peroxidase (Amersham-Pharmacia, Piscataway, N.J.), following the instructions provided by the manufacturer.
[0091] The results ( FIG. 12 ) clearly show that binding of the Cys-Cys sequence to streptavidin is reduced by at least two orders of magnitude in the presence of 10 mM DTT. In contrast, both the linear (Ser-Ser) and the selenosulfide-constrained (Cys-Sec) sequences bind more tightly in the presence of DTT, possibly due to partial unfolding of pIII, which has 4 disulfide bonds, which may increase target accessibility of the displayed peptide. Importantly, the Cys-Sec sequence binds 2 orders of magnitude more tightly than the linear Ser-Ser sequence both in the presence and the absence of DTT, indicating the presence of the selenosulfide crosslink. The reduced binding of the Cys-Sec sequence compared to the Cys-Cys sequence in the absence of DTT is likely due to the point mutation which altered a proline in the reported sequence (Giebel, et al., supra) to a threonine. Taken together, these data demonstrate that a selenosulfide-constrained peptide is stable under conditions (10 mM DTT) where the corresponding disulfide-constrained sequence is reduced to the poorly-binding linear form. It can therefore be inferred that the selenosulfide crosslink would impart the same redox stability to a constrained peptide library as the sequences described here, allowing discovery of constrained peptide ligands even under reducing conditions.
EXAMPLE VI
Identification of Semisynthetic Enzyme Inhibitors
[0092] Target Cloning and Purification. Selenopeptide phage display is used here to discover semisynthetic enzyme inhibitors. A model system, biotin ligase (also known as biotin holoenzyme synthetase (BHS)) was selected. The E. coli BHS gene (birA) was cloned into pMAL-c2x (New England Biolabs, Inc., Beverly, Mass.) in order to overexpress the gene product as an N-terminal maltose binding protein (MBP) fusion protein. To purify the protein, E. coli ER2738 was electroporated with the fusion construct pbirA. One liter of LB supplemented with 0.2% glucose and 100 μg/ml ampicillin was inoculated 1:100 with stationary phase ER2738/pbirA and incubated with shaking at 37° C. to an OD600 of 0.5. Isopropylthio-β-D-galactoside (IPTG) was added to 0.3 mM and incubation was continued for 2.5 h. After centrifugation, the cell pellet was resuspended in 50 mL column buffer (20 mM Tris-HCl, pH 7.4, 200 mM NaCl, 1 mM EDTA) and stored at −20° C. until the next day when cells were thawed and sonicated. Cellular debris was removed by centrifugation and the crude extract applied to a column of amylose/agarose bead resin. After the loading and wash steps, MBP-BirA was eluted in column buffer containing 10 mM maltose. Fractions containing protein were identified by Bradford assay and SDS-PAGE. Combined fractions were dialyzed against 50 mM [morpholino]ethanesulfonic acid (MES), pH 5.5, to remove maltose, and then against Tris buffered saline, pH 7.4 (TBS). MBP-BirA was stored in 50% glycerol at −20° C.
[0093] Modification. The TGAT library, which has a complexity of 2.4×10 8 clones, consists of displayed peptides with randomized sequence on either side of a fixed selenocysteine (Sec) followed by the essential SECIS element for Sec incorporation. Thus, on the nucleotide level, (NNK)4TGATNK(NNK) 2 (SEQ ID NO:43) gives the displayed amino acid sequence X 4 SecX 3 , where X is a randomized position. Biotinylation of TGAT library phage was carried out in ABS buffer (20 mM sodium acetate, 150 mM NaCl, pH 5.2) with 4×1011 pfu phage and 1 mM of either N-iodoacetyl-N-biotinylhexylenediamine (Pierce, Milwauke, Wis.) or N-(biotinyl)-N′-(iodoacetyl)-ethylenediamine (Molecular Probes, Eugene, Oreg.). After 1 h at room temperature, reactions were dialyzed once against ABS, followed by several changes of TBS. Modification could be verified by Western blot using anti-biotin-HRP conjugate antibody. At pH 5.2, selenocysteine residues are specifically labeled over other nucleophilic side chains such as cysteine or serine.
[0094] Panning. Panning experiments were carried out in three rounds. In the first and third rounds amylose magnetic beads (New England Biolabs, Inc., Beverly, Mass.) were used to capture phage bound to the MBP-BirA fusion. These were replaced in the second round by amylose/agarose bead resin (used in purification). Beads were blocked for 1-2 h at 4° C. in blocking buffer (0.1 M NaHCO 3 , pH 8.6, 5 mg/mL BSA, 0.02% NaN 3 ). Beads were washed with TBS containing either 0.1% (round 1) or 0.5% (rounds 2 and 3) Tween-20 (TBST). MBP-BirA target and 2.4×1010 pfu biotinylated input phage were pre-incubated 20 min and subsequently added to blocked resin. After 15 min, resin was washed thoroughly to remove unbound phage. Phage-MBP-BirA complexes were eluted in TBST containing 10 mM maltose. The eluant was titered and then amplified the next day in a 1:100 dilution of overnight culture of ER2738/pSelABC. The infected cultures were grown on LB with 2 mM Na 2 SeO 3 and incubated at 37° C. with shaking for 4.5 h. Cells were spun down and phage precipitated from the supernatant by adding 1/6 volume of 20% (w/v) polyethylene glycol-8000, 2.5 M NaCl (PEG/NaCl). Finally, phage were biotinylated and used as input phage for the next round of panning. After the third round, ssDNA was purified from individual clones by amplification of single plaques, PEG/NaCl precipitation of phage, and NaI/EtOH precipitation of DNA. Sequencing of the library phage pIII gene between Acc65 I and Eag I sites allowed identification of selected peptides.
[0095] Phage ELISA. Three selected clones (VPKQSecCQN, VTAKSecCYP, and CLQPSecYGS) were further characterized by phage ELISA to confirm specific biotinylation dependent interactions with MBP-BirA. ssDNA from each clone was converted to replicative form phage DNA (double-stranded) by reaction with Klenow fragment and sequencing primer and then electroporated into ER2738/pSelABC. Phage were amplified from individual plaques from the plated outgrowth, precipitated with PEG/NaCl and either stored in TBS at 4° C. until use or modified with biotinylating reagent. One half the rows of a Costar microtiter plate (Corning, Corning, N.Y.) were coated with 1 mg/mL MBP-BirA in 0.1 M NaHCO 3 (pH 8.6) by overnight incubation at 4° C. After coating solution was removed, blocking buffer was added to all of the plate wells and incubated for 2 h at 4° C. Blocking buffer was rinsed away with TBST (0.5% Tween-20) and four-fold serial dilutions, starting from 1011 pfu, of both modified and unmodified phage were applied to both uncoated and coated wells. The plate was incubated with gentle shaking at room temperature for 1-2 h. Next, unbound phage were washed away with TBST, and HRP/Anti-M13 monoclonal conjugate (GE Healthcare, formerly Amersham Biosciences, Piscataway, N.J.) was added in blocking buffer. After 1 h incubation at room temperature, residual antibody was washed away with TBST, and HRP substrates, 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS) and H 2 O 2 , were added. HRP turnover product was detected using a VERSAmax microplate reader, monitoring absorbance at 405 nm.
[0096] The phage ELISA compared biotinylation-dependent binding between a nonselected peptide (Sec1), the unpanned library (TGAT), non-displaying phage (no insert) and three selected clones. Biotin increased the phage affinity for MBP-birA by five fold, consistent with biotin binding to BirA. Non-displaying phage, without selenocysteine, showed only background level signals. Peptide GLQPSecYGS appears to bind more tightly than the other phage tested. | The naturally-occurring amino acid selenocysteine (Sec) is incorporated uniquely and specifically in the context of a polypeptide displayed on the surface of an amplifiable genetic particle (phage, cell or spore) in response to incorporation signals engineered in the encoding DNA. In addition to conferring the unique activities of the selenol group to the chemistry of the displayed peptide, Sec also provides a unique handle for specific chemical modification of the displayed peptide. In addition to increasing the palette of available residues in a random peptide library to 21 possibilities, the present invention also provides a means of tethering virtually any desired chemical functionality to the incorporated Sec. | 2 |
CROSS-REFERENCES TO RELATED APPLICATIONS
[0001] This application claims the benefit of and priority to U.S. Provisional Application Ser. No. 62/077,135, filed Nov. 7, 2014 and entitled “Adjustable Protective Cover for an Input Device,” the contents of which are incorporated by reference.
BACKGROUND OF THE INVENTION
[0002] The present invention relates to cases or covers for input devices, and in particular in embodiments to cases or covers that fold to provide a stand for a tablet computer.
[0003] A variety of designs have been developed for such cases. For example, Speculative Product Design US Published Application No. 20120285859 shows a tablet cover with a friction hinge at an edge of the cover. US Published Application No. 20130313142 shows a tablet cover with an intermediate hinge on an arm of the cover. Other examples of a case that folds to form a tablet stand include InCase Designs US Published Application No. 20130075281, Speculative Product Design US Published Application No. 20130241381, and Marware US Published Application No. 20140291174.
[0004] There is a need for a case/stand that is easy for a user to manipulate, and which is sturdy enough to allow typing on a supported tablet without the tablet bouncing back and forth.
BRIEF SUMMARY OF THE INVENTION
[0005] Embodiments of the invention show a device cover that folds to provide a stand for the device (e.g., a tablet computer). A friction hinge between two sections of the cover provides sufficient friction to maintain the stand at the desired angle. In order to allow the cover, with a hinge in the middle, to be easily flattened after use, a release mechanism or detent is provided in the friction hinge.
[0006] In one embodiment, the release mechanism is a non-circular portion on the hinge axle which engages a similar non-circular surface on a hinge sleeve. In one embodiment, the non-circular portions are flat, and engage each other when the first and second top cover sections are at an angle of 150 degrees or greater, or around 170 degrees or greater.
[0007] In one embodiment, the top cover folds 180 degrees around an edge to move from covering the table display to the back of the tablet. The upper portion of the cover then folds down around the friction hinge to create a stand. The lower portion of the cover is up against the bottom surface of the tablet, where a keyboard display may appear on the tablet. There are magnets in this top cover that engage the bottom of the case to hold it firmly in place during typing or touch input.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] FIG. 1 is a diagram illustrating a cover according to an embodiment of the invention, showing it enclosing a tablet.
[0009] FIG. 2 is a diagram illustrating a cover according to an embodiment of the invention, showing it folded to act as a stand.
[0010] FIG. 3 is a diagram illustrating a top cover according to an embodiment of the invention, showing the hinges.
[0011] FIG. 4 is a diagram illustrating an exploded view of a hinge structure according to an embodiment of the invention.
[0012] FIG. 5 is a diagram illustrating a disassembled hinge according to an embodiment of the invention, showing the hinge sleeve and axle.
[0013] FIG. 6 is a diagram illustrating an assembled hinge according to an embodiment of the invention.
[0014] FIG. 7 is a diagram illustrating a partially disassembled hinge according to an embodiment of the invention, showing the flat portions of the hinge sleeve and axle.
[0015] FIG. 8 is a diagram illustrating the partially assembled hinge of FIG. 7 , showing the hinge partially rotated.
[0016] FIG. 9 is a diagram illustrating a hinge plate according to an embodiment of the invention.
[0017] FIG. 10 is a diagram illustrating a cross-section of the hinge axle according to an embodiment of the invention, showing opposite flat portions.
[0018] FIG. 11A is a diagram illustrating aspects for a sequence of opening a cover according to an embodiment of the invention and folding it into a stand position.
[0019] FIG. 11B is a diagram illustrating aspects for a sequence of opening a cover according to an embodiment of the invention and folding it into a stand position.
[0020] FIG. 11C is a diagram illustrating aspects for a sequence of opening a cover according to an embodiment of the invention and folding it into a stand position.
[0021] FIG. 11D is a diagram illustrating aspects for a sequence of opening a cover according to an embodiment of the invention and folding it into a stand position.
[0022] FIG. 11E is a diagram illustrating aspects for a sequence of opening a cover according to an embodiment of the invention and folding it into a stand position.
DETAILED DESCRIPTION OF THE INVENTION
[0023] FIG. 1 is a diagram illustrating a case according to an embodiment of the invention, showing it enclosing a tablet. The case has a top cover 10 , a bottom cover 12 and a flexible side hinge 14 . The top cover 10 has two top sections 16 and 18 joined along a hinged axis 20 . The top cover sections 16 and 18 are plastic plates covered by an outer fabric or textile. A magnet 22 , shown in phantom, holds the top cover 10 closed against an enclosed tablet. Magnets 24 on top cover section 18 , shown in phantom, provide an upward magnetic force used in the folded, stand position as illustrated in FIG. 2 . Magnets 22 and 24 are internal to the top cover, and thus shown in phantom.
[0024] FIG. 2 is a diagram illustrating the case of FIG. 1 , showing it folded to act as a stand. The top cover is shown after it has been rotated 180° around hinge 14 so that section 18 of the top cover is adjacent the underside bottom of the case. The bottom 25 of the case is covered with polyurethane and includes a resin bumper 26 around the edges supporting and enclosing a tablet 28 . Top section 16 is bent around hinge axis 20 to form a stand. Magnets 24 in section 18 are adjacent a corresponding magnetic element 30 in the case bottom 25 to provide a holding force. This holding force helps firmly hold the bottom of the tablet 28 against the stand, providing stability during a typing operation on a soft keyboard which appears at the bottom of the display of tablet 28 . The magnets also allow a user to pick-up the cover and move/reposition it, without the cover releasing from the back of the tablet.
[0025] FIG. 3 is a diagram illustrating the top cover of FIG. 1 , without the textile cover, showing the hinges. Plastic supports 32 and 34 are shown forming top cover sections 16 and 18 , respectively, without the textile covers. Two metal hinge assemblies 36 and 38 are shown, attached to the plastic supports 32 and 34 .
[0026] FIG. 4 is a diagram illustrating an exploded view of a hinge assembly of FIG. 3 . Hinge assembly 36 includes structures 40 and 42 in plastic supports 32 and 34 with depressions and holes for accepting the hinge, hinge cover, and fasteners. A hinge 44 is mounted in structures 40 and 42 . Aluminum covers 46 and 48 are mounted over hinge 44 . Screws, not shown, fasten the assembly together through the screw holes.
[0027] FIG. 5 is a diagram illustrating a disassembled hinge according to an embodiment of the invention, showing the hinge sleeve and axle. Hinge 44 includes a metal plate 50 having a sleeve 52 formed by folding an extension of the metal plate. A second metal plate 54 includes a smaller sleeve 56 . An axle 58 is inserted into the sleeves and is fastened to plate 54 using rivets 60 through holes 62 in axle 58 and holes 64 in plate 54 .
[0028] FIG. 6 is a diagram illustrating an assembled hinge according to the embodiment of FIG. 5 . FIG. 6 shows the assembled structure with plate 50 joined with plate 54 using axle 58 . Screw holes 66 are shown for fastening the structure to the plastic support shown in FIG. 4 . Also shown are positioning features 68 for engaging with similar features in the plastic supports.
[0029] FIG. 7 is a diagram illustrating a partially disassembled hinge according to an embodiment of the invention, showing the flat portions of the hinge sleeve and axle. FIG. 7 shows axle 58 having a flat area 70 along its top, which engages with a flat portion 72 in hinge sleeve 52 . When the flat areas are engaged with each other, the hinge assembly is held in a flat position. As the axle turns, and the flat portion comes in contact with a circular inside portion of sleeve 52 , there is friction which provides the friction hinge force. As the axle is turned back towards the flat portion 72 of sleeve 52 , when it gets within a small number of degrees, such as 10°, it will snap into position to be aligned with flat area 52 , releasing the friction. This provides a release mechanism or detent, and makes it easy to arrange the hinge plates, and thus the two sections of the cover, in a completely flat position.
[0030] FIG. 8 is a diagram illustrating the partially assembled hinge of FIG. 7 , showing the hinge partially rotated. In the position shown in FIG. 8 , flat portion 72 of sleeve 52 has rotated away from flat portion 70 of hinge axle 58 , thus providing a friction holding force.
[0031] FIG. 9 is a diagram illustrating the hinge plate with two opposed flat portions. FIG. 9 shows a hinge plate 80 with a sleeve 82 having a top flat portion 84 with a corresponding, opposite flat portion 86 . These two, opposite flat portions engage flat portions on the top and bottom of the axle, which reinforces the release force and the stability by having applied both the top and bottom simultaneously.
[0032] FIG. 10 is a diagram illustrating a cross-section of the hinge axle according to an embodiment of the invention, showing opposite flat portions. Axle 58 includes a top flat portion 90 and bottom flat portion 92 . These engage the corresponding flat portions 84 and 86 of the hinge sleeve shown in FIG. 9 . In between flat portions 90 and 92 , the axle is circular, such as in a position 94 , to correspondingly engage with the circular inside portions of the hinge sleeve.
[0033] FIGS. 11A-E illustrate a sequence of opening a cover according to an embodiment of the invention and folding it into a stand position. FIG. 11A shows the top cover 10 with sections 16 and 18 and a side hinge 14 as shown in FIG. 1 . FIG. 11B shows the top cover starting to be folded away from the display 27 of tablet 28 . FIG. 11C shows the top cover folded nearly 360° so that is close to the back of the tablet, on the opposite side from display 27 . As illustrated by arrow 100 , the next step is to fold top portion 16 around axis 20 .
[0034] FIG. 11D shows top cover section 16 folded down at an angle to support the tablet against section 18 of the top cover. FIG. 11E shows sections 16 and 18 at a wider angle, allowing the display 27 of the tablet to be angled farther downward, closer to a flat position.
[0035] Various other embodiments are possible within the scope of the appended claims. For example, instead of flat portions on the axle and sleeve, different non-circular shapes could be used, such as a pyramid, saw-tooth, non-circular curve, etc. The hinge axle and the hinge sleeve could have additional non-circular portions for supporting the hinge assembly in a released or detent position at angles other than a flat, 180° angle. For example, two additional flat portions could be added to allow the structure to snap into and be stable at a desired, optimum viewing angle. Alternately, one hinge assembly can have up and down opposite flat structures, while the second hinge assembly can have the flat structures at the desired angle. In another embodiment, more than two detent or release angles are possible.
[0036] The fabric covering the top cover on the outside is ideally a fabric which can stretch and extend as the two sections are bent to form the stand. Conversely, a fabric or material on the inner surface of the top cover can have properties of easily compressing when folded and then returning to its original shape when laid flat again.
[0037] In one embodiment, the axis of the top cover is located somewhere between the middle of the cover and the bottom part of the cover. Having section 16 wider than section 18 allows section 16 to bend down to the support surface and hold the tablet at a variety of angles. Section 18 is wide enough to provide support against at least most of the virtual keyboard on the tablet display.
[0038] In one embodiment, the frictional force is designed to be around 2×3.6++/−0.4 kg/m, to provide sufficient standing force to hold the position of the tablet, while being a small enough force to allow a user to unfold and fold the cover without undue effort. | Embodiments of the invention show a tablet cover that folds to provide a stand for the tablet. A friction hinge between two sections of the tablet cover provides sufficient friction to maintain the stand at the desired angle. In order to allow the cover to be easily flattened after use, a release mechanism is provided in the friction hinge. | 7 |
BACKGROUND OF THE INVENTION
1. Technical Field
This invention relates generally to gloves. More particularly, this invention relates to dipped unsupported gloves. Specifically, the invention is directed to an ambidextrous or hand specific glove with a widened cuff area to aid in donning or doffing the glove; the glove may further include a bead on the cuff to resist tearing and may be fabricated on a continuous, automated chain machine or a batch or semi-batch machine because while the cuff region on the former for the glove is elliptical in cross-section and flared, the region of the former on which the end of the glove is fabricated is circular in cross-section and thus allows the beading process to be successfully undertaken.
2. Background Information
Gloves are required to be worn in many industries to protect the hands of the workers. Particular industries require gloves which are made of nitrile, polychloroprene, or latex and which extend for a distance along a worker's wrist and forearm. Because of the length of the glove and the material from which the glove is fabricated, which tends to conform to the shape of the workman's hands, it can be quite difficult for a workman to put the glove on and/or take the glove off without damaging the glove.
SUMMARY
There is therefore a need in the industry for an improved glove which is more readily able to be put on and removed, and which is less inclined to break or become damaged during this procedure.
In one aspect, the invention may provide a glove comprising a palm region; a digit region extending outwardly from a first end of the palm region; a wrist region extending outwardly from a second end of the palm region and generally in an opposite direction to the digit region; and an end of the wrist region comprising a cuff that is disposed a distance remote from the palm region; and wherein the wrist region gradually increases in width from a first width proximate the palm region to a second width proximate the cuff.
In another aspect, the invention may provide a glove comprising:
a palm region; a digit region extending outwardly from a first end of the palm region; a wrist region extending outwardly from a second end of the palm region and generally in an opposite direction to the digit region; and a bead provided at an end of the wrist region, wherein the bead is of a greater thickness than the rest of the wrist region; and wherein the glove is a hand specific glove that is fabricated on a substantially continuous automated chain machine.
In another aspect, the invention may provide a glove comprising a palm region; a digit region extending outwardly from a first end of the palm region; a wrist region extending outwardly from a second end of the palm region and generally in an opposite direction to the digit region; an end of the wrist region comprising a cuff that is disposed a distance remote from the palm region; and wherein the wrist region gradually increases in width from a first width proximate the palm region to a second width proximate the cuff; and a bead provided on the cuff, wherein the bead is of a greater thickness than the rest of the wrist region. This glove may be an ambidextrous glove or a hand-specific glove.
In another aspect, the invention may provide a former for fabricating a glove, wherein the former comprises a base; a wrist extending outwardly from the base; a palm extending outwardly from the wrist; a digit region extending outwardly from the palm and remote from the wrist; and wherein the wrist includes a first region that is of a first cross-sectional shape and a second region that is of a second cross-sectional shape. The first region of the former is generally elliptical in cross-sectional shape and the second region of the former is generally circular in cross-sectional shape.
In another aspect, the invention may provide a method of fabricating a glove comprising providing a former that includes a palm, a thumb and four digit regions extending outwardly from the palm in a first direction, and a wrist that extends outwardly from the palm in a second direction; and wherein the wrist includes a first region that gradually increases in width from the palm outwardly in the second direction; dipping the former into a vat of liquid material; removing the former from the liquid material; drying a quantity of liquid material which remains on the former so as to form the glove; and removing the glove from the former. The method may further include providing a former where the wrist further includes a second section which extends outwardly from the first section; and wherein the second section is of a constant width and the constant width of the second section is of a size equal to a widest portion of the first section. Still further, the invention may provide that the first section is generally elliptical in cross-sectional shape and the second region is generally circular in cross-sectional shape.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
A sample embodiment of the invention is set forth in the following description, is shown in the drawings and is particularly and distinctly pointed out and set forth in the appended claims.
FIG. 1 is a front elevational view of a first embodiment of a glove in accordance with an aspect of the invention;
FIG. 2 is a front elevational view of a second embodiment of a glove in accordance with an aspect of the invention;
FIG. 3 is a front elevational view of a third embodiment of a glove in accordance with an aspect of the invention;
FIG. 4 is a front elevational view of a former for fabricating the gloves of FIGS. 1, 2, and 3 ;
FIG. 5 is a cross-section of the former taken along line 5 - 5 of FIG. 4 ;
FIG. 6 is a cross-section of the former taken along line 6 - 6 of FIG. 4 ;
FIG. 6A is a front elevational view of the glove of FIG. 2 shown on the former of FIG. 4 and with the cuff of the glove in an initial position;
FIG. 6B is a front elevational view of the glove on the former showing the bottom edge of the cuff being rolled upwardly to form the bead;
FIG. 7 is a front elevational view of a fourth embodiment of a glove in accordance with an aspect of the present invention;
FIG. 8 is a front elevational view of a former for fabricating the glove of FIG. 7 ;
FIG. 9 is a cross-section of the former taken along line 9 - 9 of FIG. 8 ;
FIG. 10 is a cross-section of the former taken along line 10 - 10 of FIG. 8 ; and
FIG. 11 is an illustrative drawing of a method of manufacturing a glove in accordance with aspects of the invention.
Similar numbers refer to similar parts throughout the drawings.
DETAILED DESCRIPTION
FIG. 1 shows a glove 10 worn on an arm 12 of a workman. Glove 10 may be fabricated from nitrile or latex or any other material which causes glove 10 to generally conform to a hand of a person wearing glove. Glove 10 includes a digit region extending out from a first end of a palm region 16 generally in a first direction. The digit region includes a thumb region 14 , an index finger region 18 , a middle finger region 20 , a ring finger region 22 , and a little finger region 24 . Glove 10 is an ambidextrous glove. This means that glove 10 may be readily worn on either of the left hand or the right hand. Because glove 10 is an ambidextrous glove, thumb region 14 , index finger region 18 , middle finger region 20 , ring finger region 22 , and little finger region 24 are all aligned along a common axis. In other words, if glove 10 is viewed from the side, all of the thumb region 14 , index finger, middle finger, ring finger, and little finger regions 18 , 20 , 22 , 24 will be located in the same plane.
A wrist and forearm region 26 (hereafter referred to as the wrist region) extends outwardly from a second end of palm region 16 and in generally the opposite direction to the digit region. Wrist region 26 terminates in an end region which will be further referred to herein as a cuff 28 . Cuff 28 is disposed a distance remote from palm region 14 . Although not illustrated herein, it will be understood that cuff 28 defines an opening into which the workman will be able to insert his or her hand. It will further be understood that wrist region 26 may be of a variety of different lengths as measured between a bottom end of palm region 16 and cuff. Thus, glove 10 may terminate closer to a workman's wrist or closer to the workman's elbow.
Wrist region 26 includes a first section that is located adjacent palm region 16 and a second section that extends outwardly from first section and is located further away from palm region 16 . The second section includes cuff 28 . Wrist region 26 gradually increases in width as one moves away from palm region 16 and toward cuff 28 . Proximate palm region 16 , wrist region 26 is of a first width “W 1 ” and wrist region 26 gradually increases to a second width “W 2 ”. Thus, wrist region 26 is narrowest proximate palm region 14 and is widest a distance remote therefrom. Wrist region 26 may include a first section which gradually increases in width to the widest width “W 2 ”, and a second section which extends outwardly from the first section and is of a constant width “W 2 ”. This increase in width makes it easier for the workman to put glove 10 on and to take glove 10 off. Width “W 1 ” is of such a size that the first section of wrist region 16 is generally in abutting contact with the wearer's wrist and first portion of the wearer's forearm. Width “W 2 ” is of such as a size that second section of wrist region 16 is spaced a distance away from the wearer's forearm 12 and is generally free of contact therewith. Consequently, a gap 27 will be created between the wearer's forearm 12 and the material of the glove 10 . It is therefore easier for the wearer to insert a finger or thumb of the other hand into that gap 27 in order to grasp the material of glove 10 in order to pull glove 10 onto their hand or to pull glove off of their hand.
FIG. 1 shows that wrist region 26 gradually increases in width from proximate palm region 14 to proximate cuff 28 . So, the width of cuff 28 is the second width “W 2 ”. FIG. 2 shows a second embodiment of the ambidextrous glove 10 where the first section of wrist region 26 gradually increases in width from the first width “W 1 ” to the second width “W 2 ”. Second section of wrist region 26 starts where wrist region is of the second width “W 2 ” and the second section terminates at cuff 28 . However, from where wrist region 26 initially reaches the second width “W 2 ” to the point where wrist region 26 terminates in cuff 28 , the second section of wrist region 26 is of a substantially constant width, namely second width “W 2 ”.
FIG. 3 illustrates a third embodiment of the ambidextrous glove 10 . In this embodiment, the second section of the wrist region 26 of glove 10 is rolled to form a bead 30 . Bead 30 extends around the entire rim of cuff 28 and comprises a rolled and therefore thickened region which serves to strengthen cuff 28 . Bead 30 is thicker than the rest of wrist section and this thicker and stronger bead 30 aids in resisting tears in cuff 28 and therefore wrist region 26 as glove 10 is pulled on or taken off.
In each of the first, second, and third embodiments of the glove 10 , at least a portion of glove 10 will conform to the hand of the wearer. The portions of the glove 10 which will tend to conform to the hand of the wearer may include the thumb region 14 , index finger region 18 , middle finger region 20 , ring finger region 22 , little finger region 24 , palm region 16 , and at least part of the first section of wrist region 26 . In these aforementioned locations, an interior surface of glove 10 will abut or be positioned adjacent the wearer's skin. The rest of glove 10 , namely the parts of first section of wrist region 26 which are of a width that is greater than the wrist or forearm 12 of the wearer, will be spaced a distance away from the wearer's skin.
FIG. 4 shows a former 32 used for fabricating glove 10 . Former 32 includes a base 34 which is secured in any one of a known manner to a batch machine, a semi-batch machine or a substantially continuous automated chain machine that is used for fabricating gloves. The batch machine, semi-batch machine and the automated chain machine are well known in the art and therefore will not be described further herein.
Former 32 includes a thumb 36 and four digits which extend outwardly from a palm 38 . The digits include an index finger 40 , a middle finger 42 , a ring finger 44 , and a little finger 46 . A wrist and forearm (hereafter wrist) 48 extend between palm 38 and the base 34 . Since former 32 is utilized for fabricating ambidextrous gloves, such as glove 10 , thumb 36 and the index, middle, ring and little fingers 40 , 42 , 44 , and 46 are all positioned so that they are aligned along a common axis. In other words, if viewed from the side, all of the thumb 36 , the index, middle, ring, and little fingers 40 , 42 , 44 , 46 will be located in the same plane.
Wrist 48 includes a first section 48 a that increases in width from a width “W 1 ” to a width “W 2 ”. The narrower width “W 1 ” is provided adjacent palm 38 and the wrist 48 increases in width to width “W 2 ” some distance from palm 38 . That distance “L” may be varied in accordance with the overall length of glove 10 to be fabricated on former 32 . So length “L” will be smaller if glove 10 will terminate proximate the workman's wrist and will be substantially longer if glove 10 is to terminate proximate the workman's elbow.
Wrist 48 further includes a second section 48 b that extends outwardly from one end of first section 48 a and is of a constant width. That constant width is of the same magnitude as the widest portion of first section 48 a . The width of second section 48 b is therefore “W 2 ”. First and second regions 48 a , 48 b are different in another way and this can best be seen in FIGS. 5 and 6 . First section 48 a is generally elliptical ( FIG. 5 ) in cross-sectional shape while second section 48 b is generally circular ( FIG. 6 ) in cross-sectional shape. This difference in cross-sectional shape makes it possible for former 32 to be engaged on a substantially continuous automated chain machine so that bead 30 may be readily and easily fabricated.
Previously known formers have wrists which are generally elliptical in shape along their entire length from the palm of the former to the base thereof. Thus, when gloves are fabricated on the previously known formers, it is difficult to generate a bead on the glove cuff because the elliptical shape causes the material of the glove to flap around and roll unevenly. This made it difficult for manufacturers using previously known formers to create a consistent product and, consequently, automated chain machines or batch machines could not be used to fabricate gloves which include a rolled cuff.
It has been recognized by the inventor that fabricating a former 32 to include a second section 48 b which is not of an elliptical cross-sectional shape but is instead of a circular cross-sectional shape, such as is illustrated in FIG. 6 , makes it possible for the former 32 to be utilized in a substantially continuous automated chain machine or a batch machine or a semi-batch machine, in order to fabricate gloves 10 , particularly gloves with a bead 30 on cuff 28 .
During fabrication of glove 10 , as illustrated in FIG. 6A , former 32 is dipped into vats of a material such as nitrile or latex so that glove 10 is ultimately formed on former. In the version of glove 10 illustrated in FIG. 6A , wrist region 26 is elongated and includes a first section 26 a that progressively widens outwardly from adjacent proximate palm region 16 to a distance remote therefrom. First section 26 a is formed on first section 48 a of former 32 . Wrist region 26 further includes a second section 26 b that is of a substantially constant width, with that width being equivalent to the widest part of first section 26 a . Second section 26 b is formed on second section 48 b of former 32 . At this point, glove 10 could be removed from former 32 and would be suitable for a workman to use as the cuff 28 and wrist region 26 are widened so that glove 10 is easy to put on and take off.
However, a bead 30 may, instead, be fabricated on second section 26 b . FIG. 6B shows how this is done. Former 32 is positioned so that spaced apart opposed rollers 50 , 52 are brought into contact with the peripheral wall of second section 48 b of wrist region 48 of former 32 . Rollers 50 , 52 are caused to rotate in opposite directions “A” and “B” relative to each other. Additionally, rollers 50 , 52 are moved in a direction “C” away from base 34 or former 32 is moved in the direction “C”. Rollers 50 , 52 are initially placed in contact with second section 48 b of former 32 and then are gradually brought into contact with second section 26 b of glove 10 . This combination of motion in addition to the contact of rollers 50 , 52 with second section 26 b causes rollers 50 , 52 to roll up a length of the material of second section 26 b , thereby gradually forming bead 30 .
FIG. 7 shows a fourth embodiment of a glove in accordance with an aspect of the invention. Glove 110 is a hand-specific glove as opposed to ambidextrous glove 10 shown in FIGS. 1 and 2 . In particular, glove 110 is shaped to be worn on a workman's left hand. A glove to be worn on the workman's right hand will be a mirror image of glove 110 . Glove 110 may be fabricated out of nitrile or latex or any other material which causes glove 10 to generally conform to a hand of a person wearing glove.
Glove 110 includes a digit region which extends outwardly generally in a first direction from a palm region 116 . The digit region includes a thumb region 114 , an index finger region 118 , a middle finger region 120 , a ring finger region 122 , and a little finger region 124 . Because glove 110 is a hand-specific glove, the index finger region 118 , middle finger region 120 , ring finger region 122 , and little finger region 124 , are all aligned along a common axis. In other words, when glove 110 is viewed from the side, four of the digits, namely the index finger, middle finger, ring finger, and little finger regions 118 , 120 , 122 , and 124 are all located in the same plane. However, unlike glove 10 , the thumb region 114 of glove 110 is offset from that common axis or, when viewed from the side, thumb region 114 can be seen to be located in a different plane from the rest of the digits.
A wrist and forearm region 126 (hereafter referred to as the wrist region) extends outwardly from a second end of palm region 116 in the opposite direction to the digit region. Wrist region 126 terminates in a cuff 128 . Although not illustrated herein, it will be understood that cuff 128 defines an opening into which the workman will be able to insert his or her hand. It will further be understood that wrist region 126 may be of a variety of different lengths as measured between a bottom end of palm region 116 and cuff 128 . Thus, glove 110 may terminate closer to a workman's wrist or closer to the workman's elbow.
Cuff 128 includes a bead 130 . Bead 130 extends around the entire rim of cuff 128 and comprises a rolled and thickened region which strengthens cuff 128 . Bead 130 is thicker than the rest of wrist region 126 . This thicker and stronger bead 130 aids in resisting tears in cuff 128 as glove 110 is pulled on or taken off. Bead 130 is fabricated in the same manner as bead 30 on glove 10 . Thus, the hand-specific glove 110 shown in FIG. 7 may include a bead and be fabricated by a substantially continuous automated chain machine, or a batch machine, or a semi-batch machine as has been described previously herein with reference to glove 10 .
In glove 110 , thumb region 136 , index finger, middle finger, ring finger, and little finger regions 140 ; 142 , 144 , 146 , palm region 138 and a first section of wrist region 148 adjacent palm region 138 may be designed to conform to the shape of the wearer's hand and wrist. Thus, these regions of glove 110 tend to be in abutting contact with the wearer's hand and wrist. Wrist region 126 may widen as one moves away from palm region 116 and toward cuff 128 . Thus, proximate palm region 116 , wrist region 126 may be of a first width “W 1 ” and proximate cuff 128 , wrist region 126 may be of a second width “W 2 ”. Width “W 2 ” is greater than width “W 1 ”. Width “W 1 ” may cause the first section of wrist region 126 to come into abutting contact with the skin on wearer's wrist. Width “W 2 ” is greater than the width of the wearer's forearm and, consequently a gap 127 is created between the skin on the wearer's forearm and the interior surface of glove 132 . This increase in width or the gap 127 makes it easier for the workman to put glove 110 on and to take glove 110 off.
FIGS. 8, 8A and 8B show a former 132 used for fabricating hand-specific glove 110 . Former 132 includes a base 134 which is secured in any one of a known manner to a batch machine, a semi-batch machine or an automated chain machine that is used for fabricating gloves. Former 132 includes a thumb 136 and four digits which extend outwardly from a palm 138 . The digits include an index finger 140 , a middle finger 142 , a ring finger 144 , and a little finger 146 . A wrist and forearm (hereafter wrist) 148 extend between palm 138 and the base 134 . Index finger 140 , middle finger 142 , ring finger 144 and little finger 146 are all aligned along a common axis or, when viewed from the side, all of these aforementioned components are positioned in the same plane. Thumb region 136 is offset from common axis or, when viewed from the side, thumb region 136 can be seen to be positioned in a different plane relative to the other digits.
Wrist 148 may include a first region 148 a that increases in width from a width “W 1 ” to a width “W 2 ”. The narrower width “W 1 ” is provided adjacent palm 138 and the wrist 48 increases in width to width “W 2 ” some distance “L” from palm 138 . That distance “L” may be varied in accordance with the overall length of glove 110 to be fabricated on former 132 . So length “L” will be smaller if glove 110 will terminate proximate the workman's wrist and will be substantially longer if glove 110 is to terminate proximate the workman's elbow.
Wrist 148 may further include a second region 148 b that extends outwardly from one end of first region 148 a of wrist 148 and is of a constant width. That constant width is of the same size as the widest portion of first region 148 a . The width of second region 148 b is therefore “W 2 ”. First and second regions 148 a , 148 b are different in another way and this can best be seen in FIGS. 9 and 10 . First region 148 a is generally elliptical in cross-section shape while second region 148 b is generally circular in cross-sectional shape. This difference in shape makes it possible for former 132 to be engaged on a substantially continuous or continuous automated chain machine so that bead 130 may be readily and easily fabricated as has been described above with reference to glove 10 . In particular, it is the second region 148 b of wrist 148 that is contacted by appropriate machinery and is rolled to form bead 130 .
Referring now to FIG. 11 , a method of fabricating a glove comprises:
providing a former 32 that includes a palm 38 , a thumb 36 and four digit regions 40 , 42 , 44 , 46 extending outwardly from palm 38 in a first direction, and a wrist 48 that extends outwardly from palm 38 in a second direction; and wherein wrist 48 includes a first region 48 that gradually increases in width from palm 38 outwardly in the second direction, i.e., the first region 48 a flares outwardly;
A. dipping former 32 into a vat 70 of liquid material 72 , such as nitrile or latex; B. removing former 32 from liquid material 72 ; C. drying a quantity of liquid material 72 a which remains on former 32 so as to form the glove 10 ; D. removing glove 10 from former 32 .
The step A. above of dipping former 32 may further include the step of engaging former 32 in a substantially continuous automated chain machine, a batch machine or a semi-batch machine. The selected one of the machines is represented in FIG. 11 by box 74 . Former 32 is then dipped into the vat 70 which forms part of the selected machine 74 .
The method may further include providing former 32 where the wrist 48 further includes a second section 48 b which extends outwardly from the first section 48 a ; and wherein second section 48 b is of a constant width and the constant width of second section 48 b is of a size equal to a widest portion of the first section 48 a.
Additionally, the step A. of dipping includes dipping former 32 into vat 70 of liquid material 72 to a depth that both of the first and second sections 48 a , 48 b of wrist 48 on of former 32 will extend into the liquid material 72 . The step of providing the former may further include providing the former where the first section 48 a is generally elliptical in cross-sectional shape; and the second section 48 b is generally circular in cross-sectional shape.
The method may further include forming a bead 30 at an end of the glove 10 . This is accomplished by passing former 32 between two opposed rollers 50 , 52 which rotate in opposite directions “A” and “B” relative to each other. Rollers 50 , 52 or former 32 are moved in a direction “C” that will cause the rollers 50 , 52 to ride along a length of second section 48 b of former 32 . This means that the rollers move from a region of the second section 48 b that is free of drying liquid material 72 a to a section that includes a quantity of drying liquid material 72 a . Rollers 50 , 52 move along the section that includes the quantity of drying liquid material 72 a to cause that drying liquid material to roll into the bead 30 which extends around a circumference of the former 32 and of glove 10 . Finally, the method includes blowing a puff of air 76 into glove 10 while on former 32 in order to remove glove 10 from former 32 .
In the foregoing description, certain terms have been used for brevity, clearness, and understanding. No unnecessary limitations are to be implied therefrom beyond the requirement of the prior art because such terms are used for descriptive purposes and are intended to be broadly construed.
Moreover, the description and illustration of the preferred embodiment of the invention are an example and the invention is not limited to the exact details shown or described. | An ambidextrous or hand specific glove with a widened cuff area to aid in donning or doffing the glove is disclosed, together with a former for fabricating the glove and a method of fabricating the same. The glove may further include a bead on the cuff to resist tearing when the glove is put on or taken off. The glove may be fabricated on a continuous, automated chain machine or a batch or semi-batch machine. While the cuff region on the former for fabricating the glove is elliptical in cross-section and is flared, the region of the former on which the end of the glove is fabricated is circular in cross-section and thus allows the beading process to be successfully undertaken. | 0 |
[0001] This application is a continuation of pending U.S. patent application Ser. No. 09/764,486, filed Jan. 9, 2001, entitled, SYSTEM AND METHOD FOR REMOTE TRAFFIC MANAGEMENT IN A COMMUNICATION NETWORK.
BACKGROUND
[0002] 1. Field of the Invention
[0003] The invention relates to network communications. More specifically, the invention relates to traffic management in a network.
[0004] 2. Background
[0005] Downstream internet traffic flows on oversubscribed copper lines at rates DS-1 and below dominate the performance attributes of internet applications. Large carriers have been deploying frame relay access switches since the early nineties. ILECs and CLECs have deployed large footprints of first generation digital subscriber line access multiplexers (DSLAMs). Likewise, Internet service providers (ISP's) and cable operators have a large embedded base of legacy routers, hubs and cable modem termination systems (CMTS). These deployments have resulted in a large embedded base of legacy equipment with very limited traffic management features. Typical queuing systems are FIFO based and often a FIFO is shared across lines allowing customers to interfere with each other. One result of this FIFO queuing is that two flows directed to the same line may not be delivered in desirable order. For example, a packet or cell of a web page download or e-mail may be delivered in advance of packet or cell of the next video frame.
[0006] Bandwidth demands are continually increasing. This ever-growing demand for bandwidth necessitates traffic management techniques. While existing “last mile” infrastructure creates a performance bottleneck for downstream traffic flows, the cost of replacing this existing legacy equipment would be very high. It is useful to add traffic management capabilities to the network without replacing the legacy equipment.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] The invention is illustrated by way of example and not by way of limitation in the figures of the accompanying drawings in which like references indicate similar elements. It should be noted that references to “an” or “one” embodiment in this disclosure are not necessarily to the same embodiment, and such references mean at least one.
[0008] FIG. 1 is a block diagram of a system of one embodiment of the invention.
[0009] FIG. 2 is a block diagram of an aggregator and remote physical ports networked thereto in one embodiment of the invention.
[0010] FIG. 3 is a generalized flow diagram of traffic management in one embodiment of the invention.
DETAILED DESCRIPTION
[0011] FIG. 1 is a block diagram of a system of one embodiment of the invention. Server nodes 102 and 103 may be any server nodes that might exist on the world wide web. Such server nodes may stream audio, stream video, serve web pages, serve e-mail, or provide other types of data across a distributed network, such as web 100 , through an aggregator 104 across a trunk line 110 through a switch 112 to a line 113 and finally to customer premise equipment (CPE) 114 . Trunk line 110 may be any broadband communication link, for example, a DS-3 or an OC-3 line. Flows from aggregator 104 through the switch 112 toward CPE 114 are regarded as downstream flows. Typically, downstream flows originate at a server node such as server node 102 . Frequently, switch 112 has very limited traffic management capabilities. Aggregator 104 includes a line card 106 having a traffic manager 108 thereon.
[0012] The traffic manager 108 implements a model of the physical line rate of the line 113 of the switch 112 . The model includes a traffic shaper which limits traffic destined to that port to that line rate. By modeling the physical bit rate of the lines of the switch 112 , the traffic manager 108 knows when the incoming traffic from such servers as 102 and 103 at the aggregator destined for a particular line of the switch 112 exceeds the line rate for that line. When it does, even instantaneously, the traffic manager 108 only sends packets or cells to the switch 112 at that line rate, queuing the excess traffic within the traffic manager 108 . Within the traffic manager 108 , sophisticated traffic management capabilities may be invoked to control the individual flows destined for line 113 . For example, video packets received from server 102 may be sent out before an e-mail received from server 103 . In addition, only low priority packets may be discarded according to some packet discard policy when queues reach a certain queue threshold.
[0013] As long as the legacy switch 112 does not receive traffic for a particular port at a bit rate greater than the port is able to carry, nothing is queued at the FIFO buffers of the legacy switch 112 . The traffic manager may insure that the legacy switch 112 only receives a new packet or cell from the aggregator when the previous packet or cell has already been sent out on the line 113 . Accordingly aggregator 104 becomes the only place where traffic management occurs. The legacy switch 112 becomes transparent to traffic management because traffic to the line 113 is already managed at the upstream aggregator 104 and the legacy switch 112 adds no queuing delay to any packets or cells. The aggregator 104 can thus be said to remotely manage the traffic of the legacy switch 112 . In one embodiment, the traffic manager is implemented on an ASIC.
[0014] FIG. 2 is a block diagram of an aggregator and remote physical ports networked thereto in one embodiment of the invention. At the network edge is a legacy switch or demultiplexer 232 which has a plurality of remote physical ports (RPPs) 236 . Each such port operates at a particular transfer rate. For example, remote ports may operate at DS-1 rates or below. A FIFO 234 associated with port 236 is provided in the event that the incoming rate on the trunk 230 exceeds the RPPs transfer rate. Subsequent data would typically be queued in the FIFO. A legacy switch or demultiplexer 232 distributes incoming transmission units from the trunk line 230 to the appropriate RPP. By way of example, the trunk line 230 may be a DS-3 connection which implies it has 28 times the capacity of a DS-1.
[0015] A remote logical port (RLP) traffic manager 108 consists of a flow manager 109 followed by a RLP model 201 . Thus, where there are L physical ports, where L is an arbitrarily large positive integer, there will be L RLP traffic managers 200 , L flow managers 205 and L RLP models 201 , resulting in a one-to-one correspondence. L is expected to be rather large, such that the aggregate bandwidth of the L RPPs is much greater than the capacity of the trunk. All flows directed to a particular remote physical port are handled by its corresponding RLP traffic manager. The RLP traffic manager 200 is for remote RPP 236 . The RPP model 201 may receive N flows 202 of packets or cells, containing such information as streamed video or audio, and, for example, M flows 204 of packets or cells, containing such information as a web page download or e-mail.
[0016] In the subsequent discussion, packets, frames or cells are referred to as transmission units. Illustratively, a transmission unit may be, for example and without limitation, a layer 3 packet which may have a variable length, a layer 2 frame with a variable length, or an asynchronous transfer mode (ATM) cell which has a fixed length. Illustratively, flows are a sequence of transmission units associated with a particular customer, a particular connection, or a particular application such as video, or a combination of such associations.
[0017] The function of the flow manager 205 is to provide better bandwidth management of traffic flows than are provided at the elegacy switch 232 . Instead of a shared FIFO queue 234 for all flows, a queue 208 is provided for each incoming flow 202 , 204 . Transmission unit discard policies 206 may be applied to the buffers of both shaped and unshaped flows 202 , 204 . An example of a discard policy may be: “if queues containing video information are at least ¼ full and queues containing e-mail information are at least ⅔ full, discard the last transmission unit containing e-mail information from its queue.” Flows containing video or audio streaming information may be advantageously shaped in a flow shaper 210 . The flow shaper 210 smoothes the flow of transmission units for reception by a CPE device like a PC. By “shaping,” it is meant that the eligibility of a transmission unit for transmission is determined by the time elapsed since the transmission of the previous transmission unit from that flow. Both shaped and unshaped flows may then scheduled for transmission. For example, a transmission unit in a queue containing video information may be scheduled for transmission ahead of a transmission unit in a queue containing e-mail information All the flows, both shaped and unshaped, are scheduled by RLP scheduler 214 . Shaped flows may be given higher priority than unshaped flows. Thus, if at any time, the sum of the flow exceeds the RPP rate, e.g. DS-1, unshaped flow will backup in the queues of the traffic manager, while shaped flows are handled on a best efforts basis. The RLP scheduler 214 presents a transmission unit of the most urgent flow to the RLP model.
[0018] In one embodiment of the invention, once the individual flows are controlled using some or all of the traffic management techniques described above, the next scheduled transmission unit of a flow is presented to the RLP model to further determine eligibility for transmission. The function of the RLP model is to determine when the transmission unit is eligible to be presented to the trunk scheduler. The RLP model includes an RLP shaper and an RLP model data structure 218 . The RLP data structure 218 is loaded with shaping parameters that correspond to the transmission rate, r, of the RPP. In one embodiment, the RLP shaper 216 assures that the transmission unit is made eligible for trunk scheduling no sooner than after an elapsed time, t, since the last transmission unit for that RPP was transmitted on the trunk. The elapsed time t=s/r, where s=the size of the previous transmission unit (in bits) and r=the rate of the RPP in bits/second. This is simply the duration it takes to transmit a transmission unit on the RPP.
[0019] The parameter r is a variable obtained by provisioning from the management plane 224 . The parameter s is stored in the database with each transmission unit sent. It may also be constant as in the case of fixed length ATM cells. The trunk scheduler also feeds back a parameter, T, which is the time at which the previous transmission unit destined for the RPP was actually transmitted on the trunk. It is also stored in the data structure 218 until the next transmission unit for that RPP is transmitted. It is within the scope and contemplation of the invention to use parameters such as the inverse of a rate to calculate eligibility time of the transmission unit. The RLP model 201 assures that the RPP will be able to transmit the previous transmission unit out on the line before the next transmission unit arrives.
[0020] Each of these RLP model parameters are associated with a RLP in the data structure 218 . The RPP may be identified from the transmission unit headers by various methods. One method is to assign a unique connection identifier to all traffic destined for a particular RPP. For example an ATM VPI or MPLS tag may identify the RPP. The individual flows then may be identified by IP addresses encapsulated within the MPLS packet or ATM cell. Or in another embodiment, the flows are identified with virtual circuit identifiers (VCIs), while the RLP is identified with a virtual path identifier (VPI). In yet another embodiment, a VCI identifies a flow for processing in the flow manager 205 , and a multitude of VCIs identify the RLP. This may be accomplished by looking up a VCI in a lookup table (LUT) (not shown) to find an associated RLP identifier. Multiple VCIs all going to the same destination RPP will have the same RLP identifier associated with them. A second lookup of the RLP identifier in a second LUT will find the shaping parameters associated with the RLP. These are but a few of the many ways to distinguish flows and RPPs from transmission unit headers.
[0021] Flow shaper 210 forms its shaping based on flow parameters from flow parameter database 212 as described. The flow parameter database 212 may be populated by a control plane 220 . Control plane 220 is basically a connection or flow manager that receives connection or flow policy information from the signaling network or from the management plane. Control plane 220 includes a connection admission control (CAC) that matches inflows with downstream bandwidth. In one embodiment of the invention, the CAC ignores the RLP structure and merely subtracts the incoming flows from the available outgoing bandwidth. This method enables the trunk 230 to achieve statistical gain. In other words it operates in a work conserving manner at least some or most of the time.
[0022] The RLP shaper 216 shapes the scheduled flow established by the RLP scheduler 214 . Shaping by the RLP shaper 216 is based on, for example, legacy port rates provided by the RLP model data structure 218 . RLP model data structure 218 may be populated by the management plane 224 as described above. Population of the RLP model database 218 may be by direct entry from a manager via user interface device 226 . Alternatively, a scripting language, such as simple network management protocol (SNMP) could be used to query port management information buffer (MIB) in the legacy switch for port information and corresponding transmission rate, sometimes implied by the type of port. For example, if the type of port is DS-1, then it implies a transmission rate of 1.544 Mb/s. Responses could then be used to automatically populate the RLP model data structure 218 .
[0023] Each RLP model indicates eligibility of its shaped flow to the trunk scheduler 228 . In one embodiment, flow is only deemed eligible if sending a transmission unit will not cause a backup in the downstream queue. This can be determined based on the port rate and the timing of a previous transmission as explained above.
[0024] The trunk scheduler 228 schedules a trunk flow from the set of eligible transmission units of all the remote logical ports. In one embodiment, the transmission units are scheduled in a work conserving way for the trunk. It is expected that relatively few RLP are subject to shaping simultaneously. The other flows can fill up the trunk to make it work-conserving. By statistically multiplexing, the trunk scheduler 228 is able to supply many more physical ports than the trunk capacity alone would permit. Both levels of shaping and scheduling may be performed using pointer manipulation within the queuing structures that receive the flows.
[0025] The above described a hierarchical dual level shaping and scheduling system permits flows to be individually shaped and scheduled such that a downstream flow at the port provides a quality of service that the ports own traffic management facilities could not guarantee. This allows legacy equipment to appear to have traffic management capability where it is not present. Accordingly, the capital cost of replacing such equipment to achieve the desired quality of service may be avoided. Remote traffic management could be provided to hundreds or even thousands of RPPs using just one traffic manager which might only be one or a couple of ASICs on an aggregator line card.
[0026] While the discussion above relates to a legacy switch, this is merely illustrative. Particularly, a frame relay switch, ATM switch, Ethernet hub, router, cable modem termination system (CMTS) or even a network of these elements, may be modeled and managed as discussed above. By way of additional example, for a network of elements having significant trunking capabilities, assuming the data bottlenecks in a last line leading out of the network, that line can be modeled as the RPP. It is also within the scope and contemplation of the invention to employ additional levels of shaping and scheduling, particularly where a downstream network is to be modeled.
[0027] FIG. 3 is a generalized flow diagram of traffic management in one embodiment of the invention. At functional block 302 a transmission unit is received from an incoming trunk and distributed to an appropriate RLP traffic manager. Block 301 corresponds to flow management within a traffic manager. At functional block 304 the transmission unit (TU) is placed in a queue associated with a particular priority or flow. At functional block 306 TUs are discarded from the queue or queues according to some discard policy. A TU is indicated to be eligible for RLP scheduling once it has satisfied some flow-shaping requirements at functional block 308 . The particular requirements may be arbitrarily established, and may include any known or subsequently developed flow-shaping techniques.
[0028] At functional block 310 the most urgent TU indicated to the RLP model based on RLP scheduling policy. The scheduling policy, like the flow-shaping requirements, may be an arbitrary scheduling policy. Box 311 corresponds to the operation within the RLP model. At functional block 312 , the eligibility of the most urgent TU is determined based on shaping the flow to match the RPP transmission rate.
[0029] Box 315 corresponds to operation at the trunk scheduler. At functional block 314 , when the TU for the RLP model is the most eligible of all the TU's from all the RLP traffic managers based on the established scheduling policy, the TU is transmitted out and the transmission time of the TU is reported back to the RLP model at functional block 316 . The trunk scheduling policy may vary in sophistication from one embodiment to the next. For example, in one embodiment the trunk scheduling may be simple, first in first out (FIFO). Nevertheless provided that more sophisticated management is used in the traffic manager, improved quality of service is provided to the RPPs. Alternatively, sophisticated scheduling policies may be implemented by the trunk scheduler in addition to any other policies applied upstream.
[0030] In the foregoing specification, the invention has been described with reference to specific embodiments thereof. It will, however, be evident that various modifications and changes can be made thereto without departing from the broader spirit and scope of the invention as set forth in the appended claims. The specification and drawings are, accordingly, to be regarded in an illustrative rather than a restrictive sense. | A traffic manager to manage flows to a plurality of remote physical ports. The traffic manager employs two tiers of shaping and scheduling driven by performance characteristics of the remote physical ports. By modeling the remote physical ports within the traffic manager, flows to the physical ports can be controlled to arrive at a rate the physical ports can handle. Any backup that would otherwise occur in the queue at the physical ports is instead queued in the traffic manager. In this manner, the intelligence of the traffic manager can be leveraged to provide improved quality of service with existing infrastructure. | 7 |
FIELD OF THE INVENTION
This invention relates to a carrier onto which are mounted explosive charges so as the punch a hole in a central string of pipes in a well-type casing of an oil or gas well from within the well, over 360° of the central string of pipes.
BACKGROUND OF THE INVENTION
In the oil and gas industry, it is necessary when abandoning a well or isolating different zones of the well to seal an annular space between a central string of pipes and a surrounding protective string of pipes. To seal the annular space, it is desired to punch a hole in an innermost pipe of a series of at least two concentric strings of pipe so as to only penetrate the innermost pipe string without damaging or penetrating any other surrounding pipe strings in the well. Further, the punched pipe must not be fractured or damaged except for a limited size hole punched in a side wall.
Since it is impossible to effect a perfectly vertical well bore, there is always some degree of offset from a perfectly vertical orientation of the well bore to produce a high and a low side. Therefore, previous to the present invention, a zero degree phase gun has been lowered into a well bore and, due to the effect of gravity, the gun lays along one side (the low side) of a central casing of the well bore. A magnetizer holds the gun against the one side of the steel central casing.
The zero degree phase gun explodes a charge against the low side of the well bore.
Cement is then fed through the central casing and passed through the opening produced by the explosive charge to fill an annular gap between a central casing and a surrounding protection casing. It is important to seal the annular gap between the central casing and only the next adjacent protective pipe string so as to seal any naturally produced gases or to isolate different zones of the well bore. If an additional string of pipe is perforated by accident, it is not possible to assure that gases are being sealed by the filling with cement of the annular gap between the innermost and the most adjacent string of pipe.
Further, with a zero degree phase gun, an electrical line must be fed down through the well casing with a magnetic decentralizer, which ensures contact of the gun with a side wall of the steel well casing. As mentioned above, this contact with the well casing will be, due to gravity, on the low side of the well casing. Cement therefore poured through the well casing which is supposed to pass through the opening produced by the explosive charge into the space between the well casing and the protective casing does not usually fill this space on the high side of the well casing, leaving pockets or "channelling" through which it is possible for natural pressure to escape to the surface.
Examples of perforating charges lowered into a pipe string are disclosed in U.S. Pat. Nos. 4,688,640 to Pritchard, Jr., 4,552,234 to Revett, 3,426,850 to McDuffie, Jr., 3,280,913 to Smith, 4,352,397 to Christopher, 4,760,883 to Dunn, 3,011,550 to Kenneday, and 3,366,188 to Hicks.
The most common method of punching holes today is to use a 1 11/16 inch outside diameter steel carrier gun with a zero degree phase and a 1 11/16 inch magnetic decentralizer which is magnetized on one side. The magnet and perforating charge must face the same direction. This tool automatically finds the low side of the well bore and always perforates the casing on this low side. This results in a poor cementing of the annular space between a central string of pipe and a surrounding protection casing.
SUMMARY OF THE INVENTION
By the present invention, the disadvantages encountered in the prior art have been overcome.
An explosive charge carrier is lowered into a well pipe casing. The carrier includes wear plates that slide along the inner diameter of the pipe and which are biased against the inner wall of the well pipe casing. A string of explosive charges having a density of up to six charges per foot are mounted between disks of the carrier which are separated by 12 inches. Spaced about the periphery of the separated disks are a maximum density of six strings of charges separated by 60° for 36 explosive charges. Alternately, four strings of charge may be spaced about the periphery of the separated disks at a spacing of 90° for 16 explosive charges.
Control of the force of perforation of the perforating charges is accomplished by varying the standoff distance of the explosive charge from the casing wall to the face of the perforating charge. This can be accomplished by varying the distance between the contact surface of the wear plate when compressed radially inward and the face of the perforating charge from the inner surface of the innermost pipe string. Since the contacting surface of the wear plate will be forced against the interior surface of the well pipe casing, the distance of standoff of the perforating charge from the inner wall of the well pipe casing can be determined prior to entry of the perforating charge carrier into a well pipe casing.
Further, by controlling the spacing between the interior of the well pipe casing and the face of the penetrating charge, it is possible, when desired, to penetrate two strings of casings of, for example, 7 5/8 inches in diameter and 9 5/8 inches in diameter without penetrating a concentric third string having a diameter of 13 3/8 inches. This is achieved by locating the explosive charge approximately one inch from the inner surface of the innermost pipe string.
It is therefore an object of the present invention to provide an explosive charge carrier having a density of four strings of explosive charges with the capacity of four perforating charges per foot spaced about the periphery of an inner wall of a well pipe casing.
It is another object of the present invention to provide an explosive charge carrier having a density of four strings of explosive charges with the capacity of four perforating charges per foot spaced about the periphery of an inner wall of a well pipe casing where the density of charges may be increased to six strings of perforating charges per foot with up to six charges each, which may be spaced about the inner wall of a well pipe casing.
It is another object of the present invention to provide an explosive charge carrier having a density of four strings of explosive charges with the capacity of four perforating charges per foot spaced about the periphery of an inner wall of a well pipe casing where the density of charges may be increased to six strings of perforating charges per foot with up to six charges each, which may be spaced about the inner wall of a well pipe casing with the perforating charges being biased towards the inner wall of the well pipe casing.
It is yet still another object of the present invention to provide an explosive charge carrier having a density of four strings of explosive charges with the capacity of four perforating charges per foot spaced about the periphery of an inner wall of a well pipe casing where the density of charges may be increased to six strings of perforating charges per foot with up to six charges each, which may be spaced about the inner wall of a well pipe casing with the perforating charges being biased towards the inner wall of the well pipe casing with the distance between the wall of the well pipe casing and the face of the perforating charge being varied to control the extent of perforation of the well pipe casing and any surrounding protection casing.
These and other objects of the invention, as well as many of the intended advantages thereof, will become more readily apparent when reference is made to the following description taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a six-way decentralized casing hole puncher.
FIG. 2 illustrates the casing hole puncher located within a well pipe casing which is surrounded by a protection casing mounted in cement.
FIG. 3 is a sectional view of the casing hole puncher.
FIG. 4 is a sectional view taken along line 4--4 of FIG. 3.
FIG. 5 is a sectional view taken along line 5--5 of FIG. 3.
FIG. 6 illustrates a wear plate.
FIG. 7 illustrates a four-way decentralized casing hole puncher.
FIG. 8 is a sectional view taken along line 8--8 of FIG. 7.
FIG. 9 is a sectional view taken along 9--9 of FIG. 8.
FIG. 10 is a plan view of a separating disk.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
In describing a preferred embodiment of the invention illustrated in the drawings, specific terminology will be resorted to for the sake of clarity. However, the invention is not intended to be limited to the specific terms so selected, and it is to be understood that each specific term includes all technical equivalents which operate in a similar manner to accomplish a similar purpose.
With reference to the drawings, in general, and to FIGS. 1 through 6, in particular, a six-way decentralized casing hole puncher embodying the teachings of the subject invention is generally designated as 20. With reference to its orientation in FIG. 1, the casing hole puncher comprises a central longitudinal shaft 22 which is threaded. In FIG. 1, the embodiment shown is illustrative of a device for punching of holes over a twelve-inch length. However, by repetition of the structure shown in FIG. 1, it is possible to have multiple lengths of explosive charges from one to forty feet in length.
At the lowermost end 24 of the shaft 22 is a nut 26, which acts as a stop for further downward movement of the casing hole puncher along the length of the shaft 22. A lower disk 28 includes two supporting arms 30 which are connected to a hub 32 which fits over the shaft 22. A nut 34 is located on the opposite side of the hub 32 from the nut 26. Similarly, above and below the disk 28 are securing nuts 36 and 38, respectively. The nuts 26, 34, 36 and 38 maintain the position of the disk 28 so that the plane of the disk extends perpendicular to the longitudinal axis of the shaft 22.
Spaced above the disk 28, by approximately twelve inches is an upper disk 38, having three arms 40 terminating in a hub 42 fitted over the shaft 22. Nuts 44 and 46 secure the hub on the shaft 22, while nuts 48 and 50 secure the disk 38 on the shaft so that the plane of the disk 38 extends perpendicular to the longitudinal axis of the shaft 22.
A nut 52, located at an upper end 54 of the shaft 22, is used in securing the shaft 22 to a raising and lowering assembly. The assembly 56, shown in FIG. 2, includes a mounting cap 58 which is secured to the upper end 54 of the shaft 22 and which abuts tightly against the nut 42. A ring 60 is secured to the cap 58. A steel cable 62 is crimped by wrapping 64 so as to secure the cable 62 to the ring 60.
Located between the disks 28 and 38 is a centrally located hex nut 64. In each of the six faces of the nut 64 is located a threaded bore for receipt of a set screw 66. Secured to the nut 64 by set screw 66 is an elongated spring member 68 having two arms 70 located on opposite sides of the nut 64. The arms 70 taper radially outwardly from the nut 64 and terminate in end portions 72 which extend parallel to the longitudinal axis of the shaft 22. The terminal portions 72 are secured to a rearward surface of a wear block 74. A forward surface of the wear block 74 acts as a wear plate 76. Due to the springiness of the arm portion between the wear block and the nut 64, the wear block is biased radially outwardly away from the shaft 22.
Extending downwardly through the six pairs of slots 78, in the disk 38, is a U-shaped biwire 80. The legs 82 of the biwire 80 pass downwardly through the slots 78 through aligned openings 84 in the wear block and continue downwardly to pass through apertures 84 which extend through opposite sides of explosive charges 86. In FIGS. 1 through 3, there are six perforating charges 86 located on each of the six biwires 80 with the six biwires spaced about the periphery of disk 38 at a separation of 60°.
The biwires after passing through the six charges 86 again pass through openings 84 of the lowermost wear block 72 and through corresponding slots 88 which are aligned with the pairs of slots 78 in the upper disk 38.
As shown in FIG. 2, the casing hole puncher is lowered through an innermost well pipe casing 90, which is concentrically located within a protection casing 92. An annular space 94 is located between the well pipe casing and protection casing 92. Surrounding the casing 92 is cement 95 for anchoring the well bore without escape of gases to the surface along the side of the well bore.
By the bias of the wear blocks mounted at the ends of the elongated spring member 68, the inner wall of the well bore casing 90 is contacted by the wear blocks 72. Depending upon the location of the openings 84 in the wear blocks, the separation distance between the face of the perforation charges 86 and the inner wall of the well bore casing can be adjusted. In the example shown in FIG. 2, the perforating charges 86 are mounted so that the face of the perforating charges is aligned so as to be in intimate contact with the inner wall of the well pipe casing.
Depending upon the amount of separation between the well pipe casing 90 and surrounding strings of pipes, typically surrounded by at least two additional strings of pipe, the number of strings of pipes which are to be punched or perforated is controlled. In FIG. 2, the location of the explosive charges in intimate contact with the pipe casing 90 provides for a punching of only the pipe casing 90 to form a defined hole without further damaging or causing fractures of the pipe casing 90. When the explosive charges 86 are backed away from the inner face of the pipe casing 90, depending upon the distance from the face of the inner surface of the pipe casing, the pipe casing will be penetrated along with adjacent strings of pipe. The holes produced in this instance will be more of a destructive force rather than a deformation force resulting from the intimate contact of the explosive charge with the inner face of the pipe casing 90.
As shown in FIG. 3, primer cord 96 is shown in dotted lines as representative of a standard mechanism for exploding the explosive charges from the surface. The primer cord 96 for each string of charges on a biwire 80 passes through the holes 98 in the upper disk 38.
Holes 98 in disk 38, as well as corresponding holes in the lower disk 28, allow well fluid to pass through the casing hole puncher to facilitate lowering of the casing hole puncher. In addition, any debris disturbed by the explosion of the explosive charges is also allowed to pass through these holes without affecting the casing hole puncher.
By the use of the casing hole puncher shown in FIGS. 1 through 3, it is possible to detonate 36 explosive charges per foot through the innermost string of a series of concentric strings without any damage to surrounding strings. The placement of the face of the perforating charge in intimate contact with the inner surface of the string 90 achieves this result.
By this method, the innermost string maintains its integrity with a hole being punched in the string without any loss of metal by the explosion. The steel string 90 is simply pushed back or deformed at the location of the charge without loss of any of the metal deformed by the charge. By this method, the casing integrity is maintained without fracture of the casing.
Cement is thereby able to be passed through the casing and into the annular space between the next adjacent string for a complete filling of the annular space about the innermost string so as to isolate one zone from another when control of the zones between the strings of casing is required or when a well bore is to be abandoned. In addition, there is no "channeling" between the strings which would allow communication between a lower zone and the surface.
All previous attempts on hole punching of the innermost string with decentralized charges located in contact with the inner wall of the innermost string have only allowed a maximum of six shots per foot at only one side of the string. By the present invention, it is possible to obtain a maximum of 36 shots per foot spaced about the circumference (360°) of the innermost string or any desired lesser number of shot density.
In FIGS. 7 through 10, a four-way decentralized casing hole puncher 100 is shown. In this embodiment, two one-foot sections 102 and 104 are shown mounted on a single shaft. In this embodiment, four charges are mounted on a single biwire 106 with four strings of charges being spaced circumferentially between an upper disk 108 and a central disk 110, and between central disk 110 and lower disk 112. Therefore, sixteen shots per foot are achieved.
In FIGS. 7 through 10, similar structure to that disclosed for FIGS. 1 through 6 has been labeled with the same reference numerals as in FIGS. 1 through 6 with a prime indication. The equivalent to hex nut 64 is a four-sided nut 114.
When the perforating charges 86 are recessed from the inner wall of the innermost string by approximately one inch, they act as a perforating charge to punch through the walls of the inner string and all surrounding strings so as to pass into the surrounding cement sheet and natural formation.
Having described the invention, many modifications thereto will become apparent to those skilled in the art to which it pertains without deviation from the spirit of the invention as defined by the scope of the appended claims. | An explosive charge carrier is provided which is lowered into a well pipe casing. The carrier includes wear plates that slide along the inner diameter of the pipe and which are biased against the inner wall of the well pipe casing. A string of explosive charges having a density of up to six charges per foot are mounted between disks of the carrier which are separated by 12 inches. Spaced about the periphery of the separated disks are a maximum density of six strings of charges separated by 60° for 36 explosive charges. Alternately, four strings of charges may be spaced about the periphery of the separated disks at a spacing of 90° for 16 explosive charges. | 4 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to deflection compensating press rolls of the type having a stationary support beam and a roll shell for rotation thereabout. The shell is supported on a plurality of hydrostatic support elements, each of which has a support shoe with a bearing surface for support of the roller casing, as well as a piston-like piece which is sunk into a bore of the support beam and is sealingly connected with the swivel-mounted support shoe.
2. Description of the Prior Art
Deflection compensating rolls of this type, which are disclosed, for example, in U.S. Pat. Nos. 3,802,044 to Spillmann et al. and 3,846,883 to Biondetti, provide sag-free support by one roll of an opposing roll, wherein the roll shell of the support roll is independent of any sagging of the support beam of said roll in which the support elements are housed.
U.S. Pat. No. 3,846,883 discloses a hydrostatic support element which has a swivel-mounted support shoe connected to a piston-like member. The piston-like member has the form of a substantially solid roller. The conditions are selected such that there is a residual compressive force remaining between the support shoe and the piston-like member pressing the two parts together. The piston-like member therein is quite heavy, contains a great deal of material, and is very costly to produce, especially since it has surfaces which must be very finely machined.
SUMMARY OF THE INVENTION
The invention relates to a deflection compensating press roll which comprises a stationary axial support beam having a central bore extending therethrough and having a plurality of generally radially extending cylinders in communicating relation with the central bore, a roll shell rotatably disposed about said support beam for rotation thereabout, and a plurality of hydrostatic support elements positioned in engaged relation between the beam and the shell to exert forces therebetween. At least one of the support elements includes piston means including a generally tubular member disposed within the radially extending cylinder for transmitting fluidic pressure to support the shell, a support shoe positioned at the free end of the piston means and having a bearing surface which faces inner surface portions of the shell, and means for connecting the support shoe to the piston means to provide forces for supporting the shell.
The hydrostatic support element of the deflection compensating roll of the present invention comprises piston means which includes a cylindrical tube having generally constant inside and outside diameters. Preferably, the tube may engage in a recess in the support shoe and may be surrounded on the outside by a seal disposed between the support shoe and the tube. This arrangement provides the advantage that both the remote and free ends of the tube are exposed to essentially like hydraulic pressure. Thus, no net axial force acts on the tube. Accordingly, the tube may therefore be connected with the support shoe by relatively simple means.
A guide ring for permitting passage of the hydraulic pressure fluid may be provided between a surface of the support shoe and the inner wall of the tube. Centering of the tube on the support shoe is thereby accomplished by simple means, whereby the seal surrounding the outside of the tube is relieved.
The tube may also be provided with a ring-shaped projection at its end sunk in the cylinder bore of the beam remote from the support shoe. The diameter of the ring-shaped projection is greater than the outside diameter of the rest of the tube. A projection of this type, the outer diameter of which may be only a few tenths of a millimeter greater than the diameter of the rest of the tube, may be produced in simple fashion by regrinding the outer surface of the tube. The projection reduces the friction between the tube and the beam, in particular if the bore becomes deformed in case of sagging of the beam. In this manner, the desirability of the thin-walled tube, already favorable in comparison with a solid, piston-like member, is even further improved. Alternatively, there may be formed inside the cylinder bore within the tube a peripheral groove, within which a sealing ring is fitted. The roll is in this way quite distinctly simplified, since simple cylindrical bores in the beam suffice for admission of pistons.
Preferably, there may be provided a connecting rod for non-rigidly connecting the tube and the support shoe. The connecting rod is arranged in the axial region of the tube and the support shoe and is provided with pins disposed perpendicular to the longitudinal direction of the rod. One of the pins is passed through the tube and the other through a bore of the shoe. In this way, connection of the tube with the support shoe is accomplished in a simplified manner. It is to be understood, however, that other types of connection means may be alternatively utilized such as, for example, a chain or cooperating stops arranged on the support shoe and on the tube. Such stops are disclosed, for example, in U.S. Pat. No. 3,846,883.
Alternatively possible is an embodiment in which an axially disposed rod is rigidly fixed in the tube. The rod leads outward from the tube, away from the support shoe, and at its free end is carried slidingly in a bore, the diameter of which is smaller than the outer diameter of the tube. This arrangement provides a support element that is suitable for long strokes, axial movements in the bore in the beam. Accordingly, the beam is weakened less than a correspondingly long cylindrical tube carried in a bore matching its outside diameter.
In all of these embodiments the support shoe may be provided at its supporting surface with hydrostatic bearing pockets which are connected by throttling channels with the interior space of the tube similar to the arrangements disclosed, for example, in U.S. Pat. Nos. 3,802,044 and 3,846,883. In the present embodiment, hydrostatic, contact-free, lubrication is provided between the support shoe and the roll shell, whether or not the roll shell is rotating.
Accordingly, as will be seen from the description which follows, my invention relates to an improved development of a roll of the type disclosed in U.S. Pat. No. 3,846,883, particularly in that it provides a support element which is substantially simpler and less costly to produce, as well as having the further advantage of being adaptable to strokes of various lengths by replacement of simple parts.
It is to be noted that the bearing surface of the support shoe of the present invention may alternatively be designed in a simpler fashion wherein a hydrodynamic bearing surface obviates the need for the hydrostatic bearing pockets.
BRIEF DESCRIPTION OF THE DRAWINGS
Preferred embodiments of the invention are described hereinbelow with reference to the drawings wherein:
FIG. 1 is an axial cross sectional view of a deflection compensating press roll having hydrostatic support elements according to the invention;
FIG. 2 is an enlarged sectional view taken along line II--II of FIG. 1 illustrating a section of a hydrostatic support element;
FIG. 3 illustrates an alternative embodiment of the hydrostatic support element of FIG. 2; and
FIG. 4 illustrates another alternative embodiment of the hydrostatic support element of FIG. 2.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
In FIG. 1 there is shown a deflection compensating press roll having stationary beam 1 which is supported in a frame 2. Spherical bearing bushings 3 secured in the frame permit deflection of the ends of the beam while a pin 4 prevents rotation of the beam.
A roll shell 5 is rotatable about the beam 1. The roll shell 5 is supported on hydrostatic support elements 6 which press the shell against an opposing roll 7. Guide disks 8 having longitudinal apertures 9 are provided within the ends of the shell 5. The guide disks have parallel guide surfaces (not shown) which are guided along plane parallel guide surfaces 10 of the beam 1. The guide disks 8, on which the roll shell 5 is rotatably supported, permit movement of the roll shell 5 in the direction of pressure of the hydrostatic support elements 6, but prevent lateral movements. A roller provided with guide disks of this type is disclosed in U.S. Pat. No. 3,885,283 to Biondetti, to which reference is expressly made in this connection, so that a more detailed description will not be necessary.
A row of cylindrical bores 12 is formed in the beam and hydrostatic support elements 6 are carried therein. The cylindrical bores 12 are connected to a central bore 11 which is connected to a known supply line (not shown) of a hydraulic pressure medium. The hydraulic medium is conducted out of the intermediate space between the beam 1 and the shell 5 in a known manner (not shown), for example, by channels in the beam 1. Sealing plates 13 and 14 prevent escape of the hydraulic medium.
FIG. 2 is an enlarged illustration of the hydrostatic support element 6 in FIG. 1. The support element 6 comprises a support shoe 20 having a bearing surface 21 which cooperates with the inner surface of the roll shell 5. In the bearing surface hydraulic bearing pockets 22 are formed in a known manner. Small tubes 23 having throttle channels 24 lead from bearing pockets 22 into the pressure chamber 25 formed by the bore 12. In addition, the support element 6 contains a tube 26, which engages in a ring-shaped recess 27 in the support shoe 20. A seal 28 is provided between the outer surface of the tube 26 and the wall of the recess 27. The seal 28 comprises an inner sealing ring, which, for example, may consist of a synthetic material to facilitate sliding, and an outer pressure ring, which, for example, may consist of a rubber-like material.
As FIG. 2 further illustrates, inside recess 27 the support shoe 20 has a projection 30 within which there is an axially oriented concentric bore 31. The upper end of a connecting rod 33 is positioned within the concentric bore 31. The connecting rod 33 has a radial bore at either end thereof. The two radial bores are oriented advantageously perpendicular to each other. A first pin 32 is disposed within the upper radial bore of connecting rod 33 and within the projection 30 to pivotally connect the support shoe 20 with the connecting rod 33. A second pin 34 is disposed within the lower radial bore of connecting rod 33. Pin 34 is further supported in bores 35 of the tube 26 to pivotally connect the tube 26 with the connecting rod 33. Spacers 36 are provided at either side of connecting rod 33. This arrangement permits pivotal motion between the support shoe and the tube 26.
As further illustrated in FIG. 2, the end of the tube 26 remote from the shoe 20 is provided with a short projection 37, which has a slightly greater diameter than the rest of the tube 26. In the bore 12 of the beam 1 a radial step 38 is formed to which a sealing ring 40 with seals 41 and 42 is joined. The sealing ring 40 is held fast in the bore 12 by a spring washer 43, but is permitted to be slightly movable in said bore 12 in the radial direction, i.e., sideways.
Since the outside diameter of the projection 37 is only slightly greater, i.e., by a few tenths of a millimeter, than the outside diameter of the remaining portion of the tube, virtually equal compressive forces act on the two ends of the tube. Hence, tube 26 floats between the beam 1 and the shoe 20, so that the rod 33 has no or only minimal forces to bear. Centering of the tube 26 in relation to the shoe 20 takes place by means of the seal 28, slight deviations having no influence.
Referring to FIG. 3, wherein like reference characters indicate like parts as above, the embodiment differs from that of FIG. 2 chiefly in that a centering ring 50, having connecting apertures 51 is provided between the tube 26 and the shoe 20 to permit passage of the hydraulic pressure fluid. In this embodiment a seal 52 including a sealing ring is disposed in a groove in the tube 26. The groove may be produced, for example, in a hardened tube, simply by grinding.
Referring to FIG. 4, like reference characters indicate like parts as above. In the embodiment of FIG. 4 support shoe 20 is used which is essentially like the support shoe of the preceding embodiments. A tube 26, carried sealingly in a bore 12, engages in the support shoe 20.
In contrast to the preceding embodiments, the bore 12 is in this case somewhat shorter. Bore 12, however, is extended coaxially by a bore 60, which in the example illustrated crosses the axial bore 11.
Projecting element 61 is rigidly fixed in the tube 26. Through element 61 a rod 63 is passed which is fixed by a pin 62. At the end of the rod 63 remote from the supporting shoe 20 a guide member 64 is fixed, which is carried slidingly in the bore 60. For balancing the pressures at both sides of the guide member, at least one slot 65 is provided.
At the end of the rod 63 found inside the supporting shoe 20 a bushing 66 with spherical outer surface is fixed. The bushing is supported slidingly in a spherical bearing bushing, which is held in a central bore 68 of the support shoe 20 by a threaded bushing 70.
The mode of operation of the support element of FIG. 4 is the same as that of the elements of FIGS. 2 and 3. The hydraulic pressure fluid supplied through the bore 11 acts on the surface of the support shoe 20 through the tube 26 and presses the support shoe 20 against the inner surface of the roll shell 5, which in turn exerts a compressive force on an opposing roll, for example, the opposing roll 7 of FIG. 1.
In the embodiment of FIG. 4 a relatively great lifting movement of the support shoe 20 and of the tube 26 is possible. The necessary axial guidance of the tube 26 in its longitudinal direction is not accomplished by a corresponding length of entry into the bore 12, but specifically with the aid of the rod 63 and the bore 60. The bore 60 may therein have a relatively small diameter, so that it weakens the beam 1 less than a bore having the diameter of the bore 12.
Although support shoes with hydrostatic bearing pockets 22 and hydrostatic lubrication between the support shoe 20 and the shell 5 have been illustrated in all embodiments, simplified embodiments, in which the hydrostatic lubrication is omitted and replaced by hydrodynamic lubrication, are alternatively conceivable. In such case the bearing pockets 22 and the throttle channels 24 may be omitted. On the other hand, the support shoes 20 must be provided with tapered surfaces 71 as indicated in FIG. 4, which permit admission of the lubricating oil found in the intermediate space between the shell 5 and the beam 1 between the bearing surface 21 and the inner surface of the shell 5, so that a dynamic lubricating film may be formed. These tapered surfaces may otherwise be provided alternatively in hydrostatic lubrication. | A deflection compensating press roll is disclosed in which a stationary axial support beam has a roll shell mounted for rotation thereabout and a plurality of hydrostatic support elements provide support along the length of the roll. The support elements include a support shoe having a bearing surface which cooperates with the inside of the roll shell and a piston joined to the support shoe which includes a cylindrical tube having generally constant inside and outside diameters. | 5 |
This application is a continuation-in-part of U.S. patent application Ser. No. 10/814,598, filed Mar. 30, 2004, now abandoned to Chaves et al., entitled OPTICAL DEVICE FOR LED-BASED LAMP, which claims the benefit under 35 U.S.C. §119(e) of both provisional Application No. 60/470,691, filed May 13, 2003, to Miñano, entitled OPTICAL DEVICE FOR LED-BASED LIGHT-BULB SUBSTITUTE, and provisional Application No. 60/520,951, filed Nov. 17, 2003, to Falicoff et al., entitled COLOR-MIXING COLLIMATOR, each of provisional Application Nos. 60/470,691 and 60/520,951 being incorporated herein by reference in their entirety; and this application is a continuation-in-part of U.S. patent application Ser. No. 10/461,557, filed Jun. 12, 2003, now U.S. Pat. No. 7,021,797 to Miñano, et al., entitled OPTICAL DEVICE FOR LED-BASED LIGHT-BULB SUBSTITUTE, which claims the benefit under 35 U.S.C. §119(e) of provisional Application No. 60/470,691, filed May 13, 2003, to Miñano, entitled OPTICAL DEVICE FOR LED-BASED LIGHT-BULB SUBSTITUTE, each of U.S. patent application Ser. No. 10/461,557 and provisional Application No. 60/470,691 being incorporated herein by reference in their entirety.
BACKGROUND OF THE INVENTION
The present invention relates to light-emitting diodes (LEDs), particularly optical means for producing various far-field light intensity distributions for LEDs.
Conventional incandescent lamps of less than 100 lumens output can be matched by the latest white LEDs, albeit at a higher price. At this low end of the lumen range, the majority of incandescent applications are battery-powered. It is desirable to have an LED suitable for direct installation in the place of a burnt-out flashlight bulb.
LED's can offer superior luminous efficacy over the conventional incandescent lamps used in battery-operated flashlights. Moreover, LEDs are far more tolerant of shock, vibration, and crush-stress. Although they currently cost more to produce than the incandescents, their lifetimes are ten thousand times longer. For the sake of efficacy flashlight bulbs are run hot so they typically last only a few hours until filament failure. Also, the prices of LEDs continue to fall, along with those of the control-electronics to handle variations in battery voltage.
Indeed, LED flashlights are commercially available already, but their optics have to be adapted to the geometry of light-emitting diodes, which only emit into a hemisphere. Conventional LED lamps are unsuitable for direct installation into conventional flashlights, both electrically and optically. LED lamps are electrically unsuitable because they are current-driven devices, whereas batteries are voltage sources. Typical variations in the voltage of fresh batteries are enough to exceed an LED's tolerable operating-voltage range. This causes such high currents that the Ohmic heating within the die exceeds the ability of thermal conduction to remove it, causing a runaway temperature-rise that destroys the die. Therefore, a current-control device must accompany the lamp.
Conventional LED lamps are optically unsuitable for direct installation into the parabolic reflectors of flashlights. This is because their bullet-lens configuration forms a narrow beam that would completely miss a nearby parabola. Using instead a hemispherically emitting non-directional dome, centered on the luminous die, gives the maximum spread commercially available, a Lambertian pattern, with a sin 2 θ dependence of encircled flux on angle θ from the lamp axis. Since θ for a typical parabolic flashlight reflector extends from 45° to 135°, an LED with a hemispheric pattern is mismatched because it's emission falls to zero at only θ=90°. This would result in a beam that was brightest on the outside and completely dark halfway in. Worse yet, even this inferior beam pattern from a hemispheric LED would require that it be held up at the parabola's focal point, several millimeters above the socket wherein a conventional incandescent bulb is installed.
Another type of battery-powered lamp utilizes cylindrical fluorescent lamps. Although LEDs do not yet offer better luminous efficacy, fluorescent lamps nonetheless are relatively fragile and require unsafely high voltages. A low-voltage, cylindrical LED-based lamp could advantageously provide the same luminous output as a fluorescent lamp.
Addressing the needs above, U.S. patent application Ser. No. 10/461,557, OPTICAL DEVICE FOR LED-BASED LIGHT-BULB SUBSTITUTE, filed Jun. 12, 2003, which is hereby incorporated by reference in its entirety, discloses such LED-based lamps with which current fluorescent and incandescent bulb flashlights can be retrofitted. It often desirable, however, for LED lamps such as those described in U.S. patent application Ser. No. 10/461,557 to have other far-field intensity distributions of interest. Also, U.S. patent application Ser. No. 10/461,557 touched on the function of color mixing, to make the different wavelengths of chips 23, 24, and 25 of FIG. 2 of U.S. patent application Ser. No. 10/461,557 have the same relative strengths throughout the light coming out of ejector section 12 . This assures that viewers will see only the intended metameric hue and not any colors of the individual chips. Previously, rectangular mixing rods have been used to transform the round focal spot of an ellipsoidal lamp into a uniformly illuminated rectangle, typically in cinema projectors. Generally, polygonal mixing rods worked best with an even number of sides, particularly four and six. With color mixing for LEDs, however, such rods are inefficient because half of an LED's Lambertian emission will escape from the base of the rod.
There is thus a need in the art for effective and optically suitable LED lamps with various far-field intensity distributions and have proper shaping of their transfer sections enabling polygonal cross-sections to be used.
SUMMARY OF THE INVENTION
The present invention advantageously addresses the needs above as well as other needs by providing an optical device for LED-based lamps with configurations for various far-field intensity distributions.
In some embodiments, an optical device for use in distributing radiant emission of a light emitter is provided. The optical device can comprise a lower transfer section, and an upper ejector section situated upon the lower transfer section. The lower transfer section is operable for placement upon the light emitter and further operable to transfer the radiant emission to said upper ejector section. The upper ejector section can be shaped such that the emission is redistributed externally into a substantial solid angle. In some preferred embodiments, the transfer section is a solid of revolution having a profile in the shape of an equiangular spiral displaced laterally from an axis of said solid of revolution so as to place a center of the equiangular spiral on an opposite side of the axis therefrom.
In some embodiments, an optical device for distributing the radiant emission of a light emitter is provided. The optical device can comprise a lower transfer section, and an upper ejector section situated upon the lower transfer section. The lower transfer section can be operable for placement upon the light emitter and operable to transfer the radiant emission to the upper ejector section. The upper ejector section can be shaped such that the emission is redistributed externally into a substantial solid angle. The ejector section can further comprise lower and connecting upper portions.
Some preferred embodiments provide an optical device for distributing radiant emissions of a light emitter. The optical device can comprise a transfer section, and an ejector section situated upon the transfer section. The transfer section is operable for placement adjacent with a light emitter and operable to transfer radiant emission from the light emitter to the ejector section. The ejector section is shaped such that the emission is redistributed externally into a substantial solid angle. In some embodiments, the ejector section has an upper surface with a profile of an equiangular spiral with a center at an upper edge of said transfer section. Some embodiments further provide for the ejector section to include a surface comprised of a radial array of V-grooves. Still further embodiments provide that a surface of said transfer section is comprised of an array of V-grooves. Further, the transfer section can be a polygonal, can be faceted and/or have other configurations.
In one embodiment, the invention can be characterized as an optical device for distributing radiant emission of a light emitter comprising a lower transfer section and an upper ejector section situated upon the lower transfer section. The lower transfer section is operable for placement upon the light emitter and operable to transfer the radiant emission to the upper ejector section. The upper ejector section is shaped such that the light within it is redistributed out an external surface of the upper ejector section into a solid angle substantially greater than a hemisphere, and approximating that of an incandescent flashlight bulb. The ejector section is positioned at the same height as the glowing filament of the light bulb it replaces. It is easier to optically move this emission point, using the transfer section, than to put the LED itself at such a height, which would make heat transfer difficult, among other problems that the present invention advantageously addresses.
In another embodiment, this invention comprises a multiplicity of such transfer sections joined end-to-end, with two LED sources at opposite ends of this line-up. These transfer sections have slightly roughened surfaces to promote diffuse emission, so that the entire device acts as a cylindrical emitter, and approximating the luminous characteristics of a fluorescent flashlight bulb.
A better understanding of the features and advantages of the present invention will be obtained by reference to the following detailed description of the invention and accompanying drawings, which set forth an illustrative embodiment in which the principles of the invention are utilized.
BRIEF DESCRIPTION OF THE DRAWINGS
The above and other aspects, features and advantages of the present invention will be more apparent from the following more particular description thereof, presented in conjunction with the following drawings wherein:
FIGS. 1 a through 38 b are cross sectional views of LED lamps having various configurations of transfer and ejector lens sections (hereafter called virtual filaments) according to the present invention, with each cross sectional view accompanied, respectively, by the individual configuration's far field pattern.
FIG. 39 is a perspective view of a linear array of V-grooves.
FIG. 40 is a diagram of the angles reflected by a linear V-groove array.
FIG. 41 is a perspective view of a radial array of V-grooves.
FIG. 42 a is a perspective view of the configuration of FIG. 37 a according to the present invention.
FIG. 42 b is a perspective view showing the vector triad on the configuration of FIG. 42 a according to the present invention.
FIG. 43 is a perspective view of the construction of a V-groove on a curved surface according to the present invention.
FIG. 44 is a perspective view of a virtual filament with a curved radial V-groove array on top according to the present invention.
FIG. 45 is a perspective view of a virtual filament with a linear V-groove array on its transfer section according to the present invention.
FIG. 46 is a perspective view of a six-sided barrel-shaped virtual filament according to the present invention.
FIGS. 47 a and 47 b is a side and perspective view, respectively, of a sixteen-sided virtual filament according to the present invention.
FIG. 47 c - e show blue (465 nanometers), green (520 nanometers) and red (620 nanometers) emission patterns, respectively, of the embodiments of FIGS. 47 a - b , at the various cylindrical azimuths.
FIGS. 48 a and 48 b is a side and perspective view, respectively, of another sixteen-sided virtual filament, with a slotted ejector section according to the present invention.
FIG. 48 c depicts a 300° emission pattern produced by the collar of FIG. 48 a.
FIGS. 49 a and 49 b is a side and perspective view, respectively, of a faceted virtual filament that mixes the disparate wavelengths of a tricolor LED according to the present invention.
FIG. 50 depicts a side view of the faceted virtual filament of FIGS. 49 a and 49 b and a rectangularly cut collimating totally internally reflecting (TIR) lens focused on its output section.
FIGS. 51-53 depicts perspective views of the faceted virtual filament and the rectangularly cut collimating TIR lens of FIG. 50 as seen from three different angles.
FIG. 54 shows a perspective view of a plurality of the faceted virtual filament and collimating TIR lenses of FIG. 50 cooperated in a row.
FIG. 55 shows a luminaire for a row shown in FIG. 54 .
FIG. 56 shows an alternative virtual filament cooperated with a TIR lens.
Corresponding reference characters indicate corresponding components throughout the several views of the drawings, especially the explicit label in FIG. 1 a of LED package 20 being implied throughout FIG. 2 a to FIG. 38 a.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The following description of the presently contemplated best mode of practicing the invention is not to be taken in a limiting sense, but is made merely for the purpose of describing the general principles of the invention. The scope of the invention should be determined with reference to the claims.
The present embodiments provide light sources with predefined far-field intensities. The present embodiments can be utilized in numerous applications. For example, in some applications, the embodiments can be utilized to replace and/or substitute for other types of light sources, such as compact light sources, incandescent light sources, fluorescent light sources and other light sources. As a further example, the present embodiments can be utilized in replacing incandescent light sources in flight lights and other devices using incandescent light sources.
The present embodiments can also be utilized with the embodiments described in co-pending U.S. Provisional Patent application No. 60/520,951, filed Nov. 17, 2003, incorporated herein by reference in its entirety. The surface faceting configuration presented herein in FIG. 49A and FIG. 49B , and in co-pending U.S. Provisional Patent Application No. 60/520,951, filed Nov. 17, 2003, can be employed in variations of all of the non-faceted embodiments shown herein in order to achieve the color mixing and other benefits thereof.
The present embodiments can further be utilized with the embodiments of and in the applications described in U.S. Provisional Patent Application No. 60/470,691, filed May 13, 2003, and U.S. patent application Ser. No. 10/461,557, filed Jun. 12, 2003, incorporated herein by reference in their entirety. For example, the present embodiments can be utilized in the light sources described in U.S. Provisional Patent Application No. 60/470,691, filed May 13, 2003, and U.S. patent application Ser. No. 10/461,557, filed Jun. 12, 2003.
FIGS. 1 a through 38 b are cross sectional views of LED lamps having various configurations of transfer and ejector lens sections (hereafter called virtual filaments) according to some present embodiments, with each cross sectional view accompanied, respectively, by the individual configuration's far field pattern.
Only FIG. 1 b has the labels that are implicit in all the output patterns of the preferred embodiments in the figures that follow: semicircular polar plot 2700 shows normalized far-field distribution 2701 on semi-circular angular scale 2702 , with off-axis angle, with zero denoting the on-axis direction, and 180° the opposite direction, totally backward. This is possible for those preferred embodiments having some sideways extension so that 180° is unimpeded by the source.
In FIG. 1 a only, the light source is designated as LED package 20 with LED chips 22 , 23 , and 24 , but the same package-outline is depicted without labels in all subsequent figures of virtual filaments. This LED package represents but one possible way for the present invention to utilize multiple light emitters. Such multiple chips can have identical or different wavelengths. For example, the different wavelengths can be red, green, and blue wavelengths that span a chromaticity gamut for human color vision, or amber, red, and infrared wavelengths for night-vision devices, or other combinations of different wavelengths.
Similarly in FIG. 1 a only, the position of the focus of ellipse segment 271 is shown by star 271 f . In all subsequent figures, the focus of the profile of the transfer section is also near the bottom point of the same curve on an opposite side of a central axis.
FIG. 1 a shows virtual filament 270 comprising compound elliptical concentrator (hereinafter CEC) transfer section 271 , and an ejector section comprising outward slanting lower cone 272 and inward slanting upper cone 273 . FIG. 1 b shows that the far-field distribution of this preferred embodiment peaks in the forward direction with a ±20° extent.
FIG. 2 a shows virtual filament 280 comprising CEC transfer section 281 , multiple stacked toroids 282 , and ejector section 283 , shaped as an equiangular spiral with origin at point 283 f . FIG. 2 b shows that the maximum far-field intensity of this preferred embodiment lies on angles from about 50° to 60° off-axis, a so-called bat-wing distribution.
FIG. 3 a shows virtual filament 290 , comprising CEC transfer section 291 , cones 292 and 293 , and equiangular spirals 294 and 295 . Predominantly horizontal equiangular spiral 294 has its center at central point 294 f . Equiangular spiral profile 295 has oppositely situated center 295 f . FIG. 3 b shows the far-field distribution of this preferred embodiment, peaking at 40° off-axis and mostly confined to the range of 10-70°, also with a secondary lobe from 150-170°.
FIG. 4 a shows virtual filament 300 comprising CEC section 301 , flat 302 , sideways equiangular spiral 303 with center at point 303 f , and top equiangular spiral 304 with center at point 304 f . FIG. 4 b shows a subtle tuning of the far-field resulting from the noticeable profile-modification, as shown in FIG. 4 a , of the preferred embodiment shown in FIG. 3 a . FIG. 4 b shows that the far-field distribution of this preferred embodiment has a primary maximum on a main lobe between 40° and 60° off-axis, and a secondary maximum on a secondary rear lobe extending between 160° and 170°, nearly backwards. The next preferred embodiment is a modification of this one.
FIG. 5 a shows virtual filament 310 with CEC transfer section 311 , planar annulus 312 , equiangular spiral 313 with center at axial point 313 f , and upper equiangular spiral 314 with center at opposite point 314 f . In addition to elements in correspondence with those of FIG. 4 a are inward slanting steep cone 315 , upward slanting shallow cone 316 , and upper flat circle 317 . The normalized far-field pattern of this preferred embodiment differs significantly from the previous, as shown in FIG. 5 b , with a fluctuating forward lobe and a half-strength rear lobe.
Delving further on the theme of minor modifications, FIG. 6 a shows virtual filament 320 comprising CEC transfer section 321 , planar annulus 322 , equiangular spiral 323 with axial position of its center as shown by star 323 f , upper equiangular spiral 324 with center at opposite point 324 f , and a new element—central upper equiangular spiral 327 , also with center at 324 f . In similarity to FIG. 5 a , virtual filament 320 also comprises inwardly slanting steep cone 325 and upward shallow cone 326 . The normalized far-field pattern of the preferred embodiment of FIG. 6 a is shown by FIG. 6 b to be mainly between 30° and 50° off axis, with a rear lobe from 120° to 170°, with reduced forward emission as compared to FIG. 5 b.
FIG. 7 a depicts a preferred embodiment that is the result of small modifications of virtual filament 320 of FIG. 6 a . FIG. 7 a is a cross-section of virtual filament 330 , comprising CEC transfer section 331 , slanting conical section 332 , horizontal equiangular spiral 333 with center at axial point 333 f , steep conic edge 335 , vertical equiangular spiral 334 with oppositely situated center 334 f , and central cone 336 . FIG. 7 b shows its far-field intensity concentrated in a forward lobe within ±20° of the axis, with a strong rearward lobe peaking at 150°.
Continuing the theme of component modifications, FIG. 8 a depicts virtual filament 340 comprising CEC transfer section 341 , planar annulus 342 , inwardly slanting steep cone 335 , downward slanting shallow cone 346 , outer edge 348 , horizontal equiangular spiral 343 with center at off-axis point 343 f , vertical equiangular spiral 344 with center at opposite point 344 f , and upper equiangular spiral 347 , also with center at opposite point 344 f . FIG. 8 b shows that its far field pattern has a collimated anti-axial beam and a broader ±30° forward beam.
FIG. 9 a depicts virtual filament 350 comprising CEC transfer section 351 , dual conical flanges 352 , and upper conic indentation 353 . FIG. 9 b shows that its far-field pattern has strong forward and rear lobs, but some side emission.
FIG. 10 a depicts virtual filament 360 comprising CEC transfer section 361 , conical flange 362 , upper equiangular spiral indentation 363 with center at proximal point 363 f , and cylindrical flange 364 . FIG. 10 b shows how the rearward emission of FIG. 9 b has been eliminated.
FIG. 11 a depicts another variation of FIG. 10 a . Virtual filament 370 comprises CEC transfer section 371 , dual conic flanges 372 , central conic indentation 373 , set into central cylinder 374 . The far field pattern of FIG. 11 b shows a forward ±30° main lobe and a small secondary lobe at 125°.
FIG. 12 a depicts a variation of component proportions in the preferred embodiment of FIG. 11 a . Virtual filament 380 comprises CEC transfer section 381 , dual conic flanges 382 , and central conic indentation 383 . The far field intensity pattern of FIG. 12 b shows the same overall forward and backward emphasis of FIG. 9 b , with differing details.
FIG. 13 a depicts virtual filament 390 comprising CEC transfer section 391 , spheric section 392 , and central conic indentation 393 . In similarity to spheric ejector section 72 of FIG. 7 of U.S. patent application Ser. No. 10/461,557, both surfaces 392 and 393 are diffusing, in that rays from within and going through them are scattered diffusely into air. FIG. 13 b shows a strong forward lobe of ±40° superimposed on a weaker emission that is nearly omnidirectional.
FIG. 14 a depicts virtual filament 400 comprising CEC transfer section 401 , steeply slanting cone 402 , outer equiangular spiral 403 with axially located center 403 f , and inner equiangular spiral 404 with center at proximal point 404 f . As shown in FIG. 14 b , its far field intensity pattern has no rearward energy, and somewhat approximates a Lambertian pattern.
In a variant of the previous figure, FIG. 15 a depicts virtual filament 410 comprising CEC transfer section 411 , cylindrical stack 412 of multiple toroidal sections 412 t , inner equiangular spiral 414 with center at proximal point 414 f , and upper curve 413 tailored to refract rays coming from 414 f and being reflected at 414 and direct them tangent to 413 . FIG. 15 b shows the resultant far-field pattern to be mostly forward, within ±30°.
FIG. 16 a depicts virtual filament 420 , comprising CEC transfer section 421 , cylinder 422 , conical indentation 423 in shallower top cone 424 . FIG. 16 b shows its far-field pattern is mostly between 10° and 20° off axis.
FIG. 17 a depicts virtual filament 430 , comprising CEC transfer section 431 , outer cone 432 , and inner conical indentation 433 . In spite of the small differences from FIG. 16 a , the far-field pattern of FIG. 17 b is considerably different from that of FIG. 16 b.
FIG. 18 a depicts virtual filament 440 , comprising CEC transfer section 441 , outer cone 442 , and inner conical indentation 443 . In spite of the small differences of this preferred embodiment from that of from FIG. 17 a , the far-field pattern of FIG. 18 b is narrower than that of FIG. 17 b.
FIG. 19 a depicts virtual filament 450 comprising CEC transfer section 451 , spline curve 452 , central equiangular spiral 453 with center at proximal point 453 f , and surrounding top conic indentation 454 . FIG. 19 b shows its far-field pattern is predominantly forward, with ±20° at the half-power point.
FIG. 20 a depicts virtual filament 460 comprising CEC transfer section 461 , spheric section 462 with radius 462 r that equals 0.38 times the height of section 461 , and central equiangular spiral 463 with center at proximal point 463 f . FIG. 20 b shows its far-field pattern to lie between 100 and 600 off axis.
FIG. 21 a depicts another similar configuration, virtual filament 470 comprising CEC transfer section 471 , spheric section 472 with radius 472 r that is 0.7 times the height of section 471 , and central equiangular spiral 473 with center at proximal point 473 f . FIG. 21 b shows that the far-field pattern has significantly narrowed from the previous one.
FIG. 22 a depicts another similar configuration, virtual filament 480 comprising CEC transfer section 481 , spheric section 482 with radius 482 r that is 0.8 times the height of section 481 , and central equiangular spiral 483 with center at proximal point 483 f . Spheric section 482 is partially covered with multiple convex toroidal lenslets 482 t . FIG. 22 b shows that the far-field pattern undergoes only minor change from the previous one, with narrowing of the central beam compared to that seen in FIG. 21 b.
FIG. 23 a depicts virtual filament 490 comprising CEC transfer section 491 , spheric section 492 with radius 492 r that is 0.62 times the height of section 491 , section 492 being fully surfaced by multiple toroidal lenslets 492 t , and central equiangular spiral 493 with center at proximal point 493 f . FIG. 23 b shows how these lenslets greatly broaden the far-field pattern over that of FIG. 22 b.
FIG. 24 a depicts virtual filament 500 comprising CEC transfer section 501 , spheric section 502 with radius 502 r that is 0.76 times the height of section 501 , section 502 being surfaced by multiple convex toroidal lenslets 502 t , and central equiangular spiral 503 with center at proximal point 503 f . FIG. 24 b shows that the far field pattern is not greatly changed from that of FIG. 23 b , by section 502 having a somewhat larger radius than that of section 492 of FIG. 23 a.
FIG. 25 a depicts virtual filament 510 comprising CEC transfer section 511 , spheric section 512 with radius 512 r that is equal to the height of section 511 , section 512 surfaced by multiple convex toroidal lenslets 512 t , and central equiangular spiral 513 with center at proximal point 513 f . FIG. 25 b shows that the far field pattern is now considerably changed from that of FIG. 24 b , due to the larger radius of section 512 than that of section 502 of FIG. 24 a.
FIG. 26 a depicts virtual filament 520 comprising CEC transfer section 521 , lower spline section 522 , central equiangular spiral 523 with center at proximal point 523 f , and outer cylindrical section 524 covered with multiple convex toroidal lenslets 524 t . FIG. 26 b shows a very broad pattern that does not vary much until 130° and is only reduced by half at 180°.
FIG. 27 a depicts virtual filament 530 comprising CEC transfer section 531 , conical section 532 , central equiangular spiral 533 with center at proximal point 533 f , and cylindrical stack 534 surfaced by multiple convex toroidal lenslets 534 t . FIG. 27 b shows that this substitution of a cone for a tailored spline causes the far-field pattern to drop in the near-axis angles, as compared to FIG. 26 b . In the following FIGURE there are no such lenslets.
FIG. 28 a depicts virtual filament 540 comprising CEC transfer section 541 , conic section 542 , central equiangular spiral 543 with center at proximal point 543 f , and outer cylinder 544 . FIG. 28 b shows that the far-field pattern of this preferred embodiment is much narrower without the lenslets 534 t of FIG. 27 a.
FIG. 29 a depicts virtual filament 550 comprising CEC transfer section 551 , shallow upward cone 552 , central equiangular spiral 553 with center at proximal point 553 f , and outer concave spline 554 . FIG. 29 b shows its far-field pattern, with substantial axial emission.
FIG. 30 a depicts virtual filament 560 comprising CEC transfer section 561 , planar annulus 562 , central equiangular spiral 563 with center at proximal point 563 f , and outer cylinder 564 . FIG. 30 b shows its far-field pattern FIG. 31 a depicts virtual filament 570 comprising CEC transfer section 571 , planar annulus 572 , central equiangular spiral 573 with center at proximal point 573 f , and outer conical edge 574 . FIG. 31 b shows that far-field emission is predominantly forward.
FIG. 32 a depicts virtual filament 580 comprising CEC transfer section 581 , planar annulus 582 , upper equiangular spiral 583 with center at proximal point 583 f , outer cylinder 584 surfaced with concave toroidal lenslets 584 t , and central upper cone 585 . FIG. 32 b shows that its far-field pattern is predominantly forward, with full intensity within ±30°.
FIG. 33 a depicts virtual filament 590 comprising equiangular-spiral transfer section 591 with center at opposite point 591 f , outward cone 592 , central indentation 593 shaped as a higher-order polynomial, and steep outer cone 594 , and surfaces 595 , 596 , and 597 forming a slot. Its far-field pattern is shown in FIG. 33 b , with a sharp cutoff at 150° off-axis and only 2:1 variation from uniform intensity at lesser angles.
FIG. 34 a depicts virtual filament 600 comprising equiangular-spiral transfer section 601 with center on opposite point 601 f , protruding cubic spline 602 , and central equiangular spiral 603 with center at proximal point 603 f . Its far field pattern is shown in FIG. 34 b , and is to be compared with those of the following two preferred embodiments, in which the cubic spline protrudes more.
FIG. 35 a depicts virtual filament 610 comprising equiangular-spiral transfer section 611 with center at opposite point 611 f , protruding cubic spline 612 , and central equiangular spiral 613 with center at proximal point 613 f . FIG. 35 b shows that its far field pattern has reduced on-axis intensity compared with FIG. 34 b.
FIG. 36 a depicts virtual filament 620 comprising equiangular-spiral transfer section 621 with center at opposite point 621 f , protruding cubic spline 622 , and central equiangular spiral 623 with center at proximal point 623 f . FIG. 36 b shows that its far field pattern has reduced on-axis intensity compared with FIG. 35 b.
FIG. 37 a depicts virtual filament 630 comprising equiangular-spiral transfer section 631 with center at opposite point 631 f , planar annulus 632 , central equiangular spiral 633 with center at proximal point 633 f , and outer cylinder 634 . FIG. 37 b shows that its far field pattern has no on-axis intensity. FIG. 37 b can be compared with FIG. 30 b , given the similarity of FIG. 37 a to FIG. 30 a.
FIG. 38 a depicts virtual filament 640 comprising equiangular-spiral transfer section 641 with center at opposite point 641 f , lower conical section 642 , upper conical section 643 , and outer spline curve 644 . FIG. 38 b shows the far-field pattern. Cone 642 is a white diffuse reflector with Lambertian scattering, so that unlike the diffuse transmissive surface 392 of FIG. 13 a , it only reflects light falling on it.
Previous embodiments have complete circular symmetry, since they are formed by a 360° cylindrical profile-sweep. Thus they have no azimuthal shape variation, only the radial variation of the profile. This is because real-world 360° output patterns do not call for azimuthal variation. There is one type of azimuthal shape variation, however, having no azimuthal intensity variations in its light output. This is the V-groove.
The geometry of a linear array of V-grooves is shown in FIG. 39 . Reflective 90° V-groove array 650 is bordered by x-z plane 651 and y-z plane 652 . Incoming ray 653 is reflected at first groove wall 650 a become bounce ray 654 , then reflected at second groove wall 650 b to become outgoing ray 655 . Incoming ray 653 has projection 653 yz on border plane 652 and projection 653 xz on border plane 651 . Bounce ray 654 has projection 654 yz on border plane 652 and projection 654 xz on border plane 651 . Outgoing ray 655 has projection 655 yz on border plane 652 and projection 655 xz on border plane 651 .
FIG. 39 also shows macrosurface normal N lying perpendicular to the plane of V-groove array 650 , which in the case of FIG. 39 is the xy plane. The directions of projected rays 653 xz and 655 xz obey the law of reflection from a planar mirror with the same surface normal. But on yz plane 652 , outgoing projection 655 yz has the opposite direction of incoming projection 653 yz , which has in-plane incidence angle ψ. Thus linear V-groove array 650 acts as a combination of retroreflector and conventional reflector. That is, when incoming ray 653 has direction vector (p,q,r), then outgoing ray 655 has direction vector (p,−q,−r). This condition, however, only holds for those rays undergoing two reflections. Of all possible input-ray directions, the fraction that is reflected twice is 1−tan(ψ).
The configuration pertinent to the present invention is when surface 650 is the interface between a transparent dielectric, such as acrylic or polycarbonate, lying above the surface (i.e. positive z) and air below it. The particular case shown in FIG. 39 is also valid for total internal reflection, which occurs whenever the incidence angle θ of a ray on the dielectric-air interface exceeds the local critical angle
θ c =arcsin(1/n) for refractive index n. Since the unitary normal vectors on the 2 sides of the grooves are (0, 0.5, 0.5) and (0,−0.5, 0.5), the condition for total internal reflection can be vectorially expressed as
( p,q,r )(0,±0.5, 0.5)<cos θ c
which can be rearranged to yield
| q |+(1 −p 2 −q 2 )<[2(1−1 /n 2 )]
FIG. 40 shows contour graph 660 with abscissa p and ordinate q. Legend 661 shows the fraction of rays that are retroreflected by total internal reflection. For p=0, the maximum q value for which there is total internal reflection for the 2 reflections is
|cos −1 q |<45°−θ c
which amounts to a vertical width of ±2.8° for acrylic (n=1.492) and ±6° for polycarbonate (n=1.585). These small angles are how much such incoming rays are not in plane 651 .
More pertinent to the present invention is radial V-groove array 670 shown in FIG. 41 . Crest-lines 671 and trough-lines 672 are the boundaries of planar triangles 673 , which meet at the crest-lines and trough-lines with 90° included angles 674 .
In FIG. 37 a , the genatrix curve of upper surface 633 has the form of an equiangular spiral. It is possible to impose a radial V-groove array on such a surface, so that crest-lines 671 of FIG. 41 would become curved downward, depressing the center point.
FIG. 42 a is a perspective view of the preferred embodiment of FIG. 37 a . Virtual filament 680 comprises equiangular-spiral transfer section 681 , equiangular-spiral top surface 683 , and cylindrical side surface 684 , the apparently polygonal shape of which is a pictorial artifact. Crest curves 683 c are shown as twelve in number, to correspond with crest-lines 671 of FIG. 41 .
FIG. 42 b is another perspective view of the same preferred embodiment, but with surfaces 683 and 684 of FIG. 42 a removed. Twelve crest-curves 683 c are shown, one shown with tangent vector t, normal vector n, and their vector product the binormal vector b=t×n. If a crest-curve were the path followed at uniform speed by a particle, then its velocity vector lies along tangent vector t and its acceleration vector is the negative the normal vector n. The latter is so that it will coincide with the surface normal of the surface. Because each crest-curve lies in a plane, binormal vector b is constant, meaning the crest-curves have zero torsion.
FIG. 43 is a perspective view of the construction of a V-groove on a curved surface according to the present invention.
In modifying surface 683 of FIG. 42 a to become like radial-groove array 670 of FIG. 41 , the curvature of the crest-lines would make the groove surfaces become non-planar. In fact, such surfaces would be the envelopes of elemental planes coming off each point on the curve at a 45° angle, as shown in FIG. 43 . Incompletely swept equiangular spiral surface 690 is identical to surface 683 of FIG. 42 a . Part of the sweep is unfinished so that crest-curve 691 can be clearly seen. Tangent to it are three elemental planar ridges 692 with 90° interior angles. Let a crest curve be specified by the parametric function P(t), where t is the path-length along said crest-curve, with normal vector n(t) and binormal vector b(t). Any point X on a 45° plane touching the crest-curve at P(t) is specified by
( X−P ( t ))·( n ( t )± b ( t ))=0 (1)
with the ‘±’ referring to there being two such 45° planes corresponding to the walls of a 90 V-groove. Varying t gives a family of such planes. In order to calculate the envelope surface to this family of planes, differentiate Equation (1) with respect to parameter t, giving
- ⅆ P ( t ) ⅆ t · ( n ( t ) ± b ( t ) ) + ( X - P ( t ) ) · ( ⅆ n ( t ) ⅆ t ± ⅆ b ( t ) ⅆ t ) = 0 ( 2 )
The orthogonal vector triad formed by the parametrically specified unit vectors t(t), n(t), and b(t) is called the Frenet frame of the curve it follows as t varies. Each of these three vectors has a definition based on various derivatives of the equation for P(t). Differentiating these definitions with respect to t gives the Frenet equations, well-known in differential geometry. A laborious combination of the Frenet equations with Equation (2), and eliminating t, finally yields
( X−P ( t ))· t ( t )=0 (3)
Equation (3) and Equation (1) must be fulfilled simultaneously for each point X of the envelope surface. Equation (3) establishes that the same vector X−P is normal to tangent vector t, while Equation (1) implies that the vector X−P is normal to n±b. Thus X−P, for a point satisfying equations (1) and (3), must be in the direction n−b, because n and b are orthogonal unit vectors so that (n−b)·(n+b)=0, i.e.,
X−P ( t )= s (− n ( t )± b ( t )) (4)
This is the parametric equation of the two envelope surfaces of the ridge. The radial parameter is t and transverse parameter is s, with one ridge for +b(t) and the other for −b(t). Curves 683 c of FIG. 42 b will be crest curves if we take s>0 for both ridges (with s=0 for the crest curves) and they will be trough curves if s<0 (with s=0 for the trough curves in this case). More pertinently,
X ( t,s )= P ( t )+ s (− n ( t )± b ( t )) (5)
is the equation of the envelope surface as a function of the crest equation P(t), and its normal and binormal vectors. The parameter s extends to the value of s that at the bottom of the groove, where it meets the corresponding point on the next ridge.
The upshot of this differential-geometry proof is that each of the planes of FIG. 43 contributes thick lines 693 to the envelope surface of the curved V-groove. Thick lines 693 of FIG. 43 in fact represent the second term in Equation (5). If successive lines 693 cross as they issue from closely neighbouring points, then the resultant envelope surface may have ripples or even caustics (which are physically unrealisable). In the present invention, any such mathematical anomalies would be too far from the crest curve to be of relevance.
FIG. 44 is a perspective view of virtual filament 700 , comprising equiangular-spiral transfer section 701 , radial V-grooves 702 , and cylindrical sidewall 703 . Only twelve V-grooves are shown, for the sake of clarity, but an actual device may have many more. The utility of such grooves is that they enable the designer to avoid the use of a coated reflector.
FIG. 45 shows virtual filament 710 , comprising transfer section 711 with longitudinal V-grooves, and ejector section 703 . As shown in FIG. 45 , V-grooves can also be used on the transfer section of the present invention, enabling a cylindrical shape to be used.
The discussion of FIG. 2 of U.S. patent application Ser. No. 10/461,557 touched on the function of color mixing, to make the different wavelengths of chips 23 , 24 , and 25 have the same relative strengths throughout the light coming out of ejector section 12 . This assures that viewers will see only the intended metameric hue and not any colors of the individual chips. Previously, rectangular mixing rods have been used to transform the round focal spot of an ellipsoidal lamp into a uniformly illuminated rectangle, typically in cinema projectors. Generally, polygonal mixing rods worked best with an even number of sides, particularly four and six. With color mixing for LEDs, however, such rods are inefficient because half of an LED's Lambertian emission will escape from the base of the rod.
The following preferred embodiments of the present invention remedy this deficit by proper shaping of its transfer section. This shaping enables polygonal cross-sections to be used in the present invention.
FIG. 46 depicts virtual filament 720 , comprising hexagonal transfer section 721 and hemispheric ejector section 722 . Within package 723 are red LED chip 723 r , green chip 723 g , and blue chip 723 b . Transfer section 721 comprises expanding bottom section 721 b , mid-section 721 m with constant cross-section, and contracting upper section 721 u . The shape of sections 721 b and 721 u acts to prevent the escape of rays that a constant cross section would allow if it extended the entire length of transfer section 721 . Similar to the grooves of FIG. 44 and FIG. 45 , a polygonal transfer section would constitute a departure from complete rotational symmetry.
FIG. 47 a is a side view of virtual filament 730 comprising sixteen-sided off-axis ellipsoid 731 , conical ejector section 732 , and mounting feet 734 . FIG. 47 b is a perspective view of the same preferred embodiment, also showing spline top surface 733 . FIG. 47 c shows the blue (465 nanometers) emission pattern of this preferred embodiment, at the various cylindrical azimuths, 0° azimuth indicated by reference numeral 735 , 45° azimuth indicated by reference numeral 736 , 90° azimuth indicated by reference numeral 737 , and 135° azimuth indicated by reference numeral 738 , and as indicated in the legend at upper right. FIG. 47 d shows the green (520 nanometers) emission pattern of this preferred embodiment, at the various cylindrical azimuths 735 - 738 and as indicated in the legend at upper right. FIG. 47E shows the red (620 nanometers) emission pattern of this preferred embodiment, at the various cylindrical azimuths 735 - 738 and as indicated in the legend at upper right.
FIG. 48 a is a side view of virtual filament 740 comprising sixteen-sided off-axis ellipsoid 741 , conical ejector section 742 , conical collar 744 , and cylindrical connector 745 . FIG. 48 b is a perspective view of the same preferred embodiment 743 . The purpose of the narrowing by collar 744 is to produce the 300° emission pattern 747 shown in FIG. 48 c.
FIG. 49 a is an exploded side view of faceted virtual filament 750 and tricolor LED package 755 being inserted into and optically coupled to the filament 750 . Beyond polygonally-shaped transfer sections are more complex departures from circular symmetry. Virtual filament 750 comprises an output section spanned by arrow 751 , transfer section 752 , and mounting feet 753 . Faceted virtual filament 750 is a single piece of plastic, such as acrylic, the surface of which is covered by planar facets 754 . The two mounting feet 753 are designed to be proximate to the outer surfaces of LED package 755 , to aid in alignment and bonding of virtual filament 750 to package 755 . In one embodiment of the invention, adhesive is applied to the inner sidewalls of feet 753 for bonding to LED package 755 . In this instance the inner sidewall of each leg 753 has a surface that is substantially parallel to the proximate edge surface of LED package 755 . Optical coupling of the bottom of virtual filament 750 to the top surface of LED package 755 can be achieved by several means, such as use of optical adhesives, non-curing and curing optical gels (such as available from Nye Optical Products of Fairhaven, Mass.) or index matching liquids (such as available from Cargille Laboratories of Cedar Grove, N.J.).
FIG. 49 b is an exploded-part perspective view showing rectangular LED package 755 as removed from virtual filament 750 . Within reflector cup 757 are red chip 758 r , green chip 758 g , and blue chip 758 b . Cup 757 is filled with transparent epoxy (not shown) up to top 756 of package 755 . Top 756 is optically bonded to the bottom of faceted virtual filament 750 . This three-chip configuration is an example of the present invention incorporating multiple light sources. The three chips shown could also be amber, red, and infrared, suitable for illuminators compatible with night-vision devices, and other combinations.
Typically the base of a mixing virtual filament is larger than the emitting surface of the RGB LED illuminating it. In one preferred embodiment the inner diameter of the sixteen-sided polygonal shaped base of the mixing optic 750 is 20% larger than the diameter of the circular exit aperture of the RGB LED 755 . In the case where the RGB LED 755 has a non-circular exit aperture, the base of the virtual filament is made sufficiently large to completely cover the exit aperture of the LED.
FIG. 50 is a side view showing TIR lens 5030 with its focus at output section 751 of faceted virtual filament 750 .
FIG. 51 is a view from below also showing faceted virtual filament 750 , LED package 755 , and TIR lens 5030 , the latter comprising facets 5031 and flat cut-out planes 5032 .
FIG. 52 shows the rectangular shape of TIR lens 5030 , positioned above faceted virtual filament 750 . Also shown is LED package 755 coupled to the bottom of virtual filament 750 . There are four mounting feet 5013 , somewhat smaller than the two shown in FIG. 49A , so as not to leak a greater amount of light from LED 755 .
FIG. 53 is a perspective view from above showing virtual filament 750 and LED package 755 . Rectangularly cut TIR lens 5030 has planar side walls 5032 and slightly indented upper surface 5033 .
FIG. 54 shows lens 5040 comprising a row of rectangular TIR lenses 5030 , and endmost virtual filament 750 .
FIG. 55 shows endmost virtual filament 750 and circuit board 5050 upon which it is mounted. Sidewalk 5055 hold row lens 5040 , flat holographic diffuser 5060 just above it, and outer cover 5070 , which is optionally a holographic diffuser. Transverse arrow 5061 shows the long axis of the elliptical pattern of holographic diffuser 5060 . Longitudinal arrow 5071 shows the long axis of the elliptical pattern of a holographic diffuser deployed on cover 5070 . These diffusers cause a distant viewer to see a narrow line of light on cover 5070 . It will have the color of the metameteric resultant of the component colors mixed by faceted virtual filament 750 .
FIG. 56 shows an alternative virtual filament configuration. Reflector cup 5061 is analogous to reflector cup 21 of FIG. 49B , in that it contains the system's light-emitting chips. Six-fold compound parabolic concentrator (CPC) section 5062 widens to hexagonal rod 5063 . This CPC section can alternatively be a combination of an equiangular and a parabolic curve, hereinafter referred to as an equiangular-spiral concentrator, to avoid leakage. At the top of rod 5063 , another parabolic (or equiangular spiral) section 5064 narrows the rod again. This widens the angular swath of light from the range of guided angles, about ±48°, to about the full ±90° of LED package 755 . Other even-polygon cross sections for the rod can also be used. Connected to rod 5063 is hemispheric lens 5065 , positioned just under rectangular TIR lens 5066 and delivering light thereinto. Sections 5062 , 5063 , 5064 and 5065 can, in some embodiments, be formed all of one piece of transparent plastic, such as acrylic or polycarbonate. Light received into section 5062 is mixed by section 5063 and emitted out section 5065 into collimating lens 5066 .
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 as set forth in the claims. | An optical device for coupling the luminous output of a light-emitting diode (LED) to a predominantly spherical pattern comprises a transfer section that receives the LED's light within it and an ejector positioned adjacent the transfer section to receive light from the transfer section and spread the light generally spherically. A base of the transfer section is optically aligned and/or coupled to the LED so that the LED's light enters the transfer section. The transfer section can comprises a compound elliptic concentrator operating via total internal reflection. The ejector section can have a variety of shapes, and can have diffusive features on its surface as well. The transfer section can in some implementations be polygonal, V-grooved, faceted and other configurations. | 5 |
FIELD OF THE INVENTION
[0001] The invention relates to a gearbox control module and to a gearbox for a vehicle.
BACKGROUND TO THE INVENTION
[0002] For the control of automatic gearboxes, use is made of electronic controllers which are either arranged in the interior of the gearbox housing (integrated control unit) or are mounted onto the gearbox housing from the outside (attachment control unit).
[0003] Attachment control units can have the advantage over integrated control units that they are subjected to lower temperatures and can thus be designed to be cheaper. It can however be a disadvantage that attachment control units take up a very large amount of structural space in the engine bay, and the outlay for leading electrical lines from the outside to the sensors and actuators situated in the interior of the gearbox is higher.
[0004] Integrated control units are generally constructed as so-called electronic control modules and may comprise an electronic circuit or an electronics component (“transmission control unit”, TCU), sensors, at least one plug connection for connecting to the vehicle wiring loom, and electrical interfaces for the activation of actuators.
SUMMARY OF THE INVENTION
[0005] It is the object of the invention to provide a gearbox control module which is easy to construct and easy to cool.
[0006] Said object is achieved by means of the subject matter of the independent claims. Further embodiments of the invention will emerge from the dependent claims and from the following description.
[0007] One aspect of the invention relates to a gearbox control module for a gearbox.
[0008] In one embodiment of the invention, the gearbox control module comprises an electronics component with an electronic circuit for controlling the gearbox, electrical connections for example for connecting the electronics component to a wiring loom (for example in the engine bay) and/or for connecting the electronics component to the gearbox (for example via lines in the interior of the gearbox) and a module carrier on which the electronics component and the electrical connections are mounted. The module carrier is designed as a cover for sealingly closing off a gearbox interior.
[0009] In other words, the module carrier can simultaneously perform the function of a cover or of an oil pan for the gearbox. It is possible in this way for one component (cover or oil pan) to be omitted, and it is ensured that an outer side of the gearbox control module is situated in the relatively cool engine bay. Since the gearbox control module can also perform the function of a cover and some of its components are arranged in the interior of the gearbox, it is possible for the gearbox control module to have a small structural space requirement in the engine bay. With the gearbox control module, the outlay in terms of assembly and the number of individual parts required can be reduced.
[0010] Here, the low cabling outlay for a control unit integrated into the gearbox can be maintained: in general, it is merely necessary for the electrical lines from the electronics component (TCU) to the vehicle wiring loom to be led out of the gearbox interior into the engine bay in a sealed manner. This may be achieved for example by means of a gearbox plug connector.
[0011] The module carrier has the function of mechanically holding and supporting all of the components of the gearbox control module. The module carrier may be produced from plastic or from a metallic substrate (for example aluminum). With the covering of the gearbox by means of the module carrier, it can be achieved that the gearbox interior is separated from the engine bay in a manner impermeable to gearbox oil. The module carrier may be of oil-impermeable design and has, for example, no bores or other cutouts that are not closed off.
[0012] In one embodiment of the invention, the module carrier comprises a module carrier plate. The cover can thus form a substantially areal lid which can be mounted on the gearbox by way of a flange of the gearbox housing. The module carrier or the module carrier plate may thus have an inner surface facing toward the gearbox interior and an outer surface facing toward the engine bay. Some of the components of the gearbox control module, which are intended to be arranged in the interior of the gearbox, may be mounted on the inner surface. By way of the outer surface, the gearbox control module can release heat into the engine bay.
[0013] In one embodiment of the invention, the gearbox control module comprises a gearbox plug connector for the connection of a wiring loom to the gearbox control module. The gearbox plug connector is integrated into the module carrier for example through an opening or cutout in the module carrier. In this way, the gearbox plug connector can be installed already during the production of the gearbox control module, without mechanical tolerance compensation.
[0014] With the integrated gearbox plug connector, it is also possible for the mechanical outlay for the connection to the vehicle wiring loom to be reduced. Tolerance compensation that is required for conventional control units for the installation of the plug connector during the installation of the gearbox control module into the gearbox housing can be dispensed with, because the plug connector can be integrated directly in the module carrier.
[0015] The gearbox plug connector normally has the function of producing an interface from the electronics component (TCU) in the gearbox interior to the vehicle wiring loom in the engine bay.
[0016] The plug connector may be installed, as a separate part, into the module carrier plate. In the case of the module carrier being formed from plastic, the plug connector may also be injection-molded directly into the module carrier.
[0017] In one embodiment of the invention, the gearbox plug connector, as a separate part, is installed sealingly into a cutout in the module carrier.
[0018] In one embodiment of the invention, the gearbox plug connector is injection-molded into the module carrier.
[0019] In one embodiment of the invention, the electronics component is arranged on an inner side of the module carrier and the electronics component is thermally connected to the module carrier. The gearbox control module can utilize the low ambient temperature of the engine bay for the cooling of the electronics of the electronics component. The electronics component (TCU) may be thermally connected to the module carrier such that power losses can be dissipated out into the relatively cool engine bay.
[0020] The cooling surface of the gearbox control module (for example the outer side of the module carrier) may be situated outside the gearbox. Via the module carrier, the heat can be released to the relatively cool engine bay environment. This can result in significantly lower outlay for the cooling of the electronics.
[0021] The electronics component (TCU) and the electrical connections thereof may be arranged in the interior of the gearbox. Accordingly, it is possible for all components to be connected to interfaces within the gearbox with low cabling outlay.
[0022] Aside from the electronics component (TCU) and the gearbox plug connector, it is possible for electrical connections, sensors and an intermediate plug connector to be integrated into the gearbox control module: said elements may be installed on the inner side of the module carrier. The electrical connection means and/or the electrical connections may also serve for the connection of the components of the gearbox control module to one another. The intermediate plug connector may be used for the connection of an electrical line from the interior of the gearbox.
[0023] In one embodiment of the invention, the module carrier is in the form of a printed circuit board or an insert-molded lead frame. In this way, the functions of the components of electrical connection means (that is to say the electrical connections) and module carrier can be integrated in one component. Said component performs the function of the cover of the gearbox. For example, in this embodiment, the gearbox plug connector is likewise integrated into said component.
[0024] In one embodiment of the invention, a motor control component for an electric motor of the gearbox is mounted on an outer side of the module carrier. If an electric motor is required for the gearbox, it may be expedient for the electronic components for the actuation thereof to be mounted on the outer side of the gearbox control module. Aside from the lower temperatures, this may have the advantage that said components do not need to be protected from gearbox oil. Since said components are normally connected in series in the electrical line, the number of lines that are led into the gearbox interior in an oil-impermeable manner does not need to change.
[0025] A further aspect of the invention relates to a gearbox for a vehicle, for example an automatic gearbox.
[0026] In one embodiment of the invention, the gearbox comprises a housing with an opening (for example for the leadthrough of electrical lines into an interior of the gearbox) and comprises a gearbox control module, such as is described above and below, which sealingly closes off the opening.
[0027] The gearbox control module can be produced by a supplier independently of the final assembly process for the gearbox. The gearbox manufacturer can install the gearbox control module into its gearbox in a simple manner. Since the opening is also closed off when the gearbox control module is installed, the assembly process is simplified.
[0028] In one embodiment of the invention, the gearbox also comprises a hydraulics control module. The gearbox may comprise hydraulic components which are actuated by the hydraulics module, which in turn can be actuated by the gearbox control module. The opening in the gearbox housing may be delimited by a flange to which the gearbox control module is connected. The hydraulics control module may be mounted on the flange between the gearbox control module and the opening. In this way, the hydraulics control module is installed in a space-saving manner in the gearbox so as to be covered by the gearbox control module.
[0029] In this way, the positioning of the gearbox control module in the gearbox can also be simplified because the gearbox control module is connected directly to the gearbox housing, and is not connected indirectly to the gearbox housing via the hydraulics control module.
[0030] Exemplary embodiments of the invention will be described in detail below with reference to the appended figures.
BRIEF DESCRIPTION OF THE FIGURES
[0031] FIG. 1 shows a detail from a gearbox according to one embodiment of the invention.
[0032] FIG. 2 shows a detail from a gearbox according to a further embodiment of the invention.
[0033] FIG. 3 shows a detail from a gearbox according to a further embodiment of the invention.
[0034] Identical or similar parts are basically denoted by the same reference signs.
DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS
[0035] FIG. 1 shows a detail of a gearbox 10 which is enclosed by a gearbox housing 12 . The gearbox housing 12 divides an interior 14 of the gearbox 12 from an engine bay 16 .
[0036] The gearbox housing 12 comprises a two-step flange 18 , in the interior of which there is installed a hydraulics control module 20 . The hydraulics control module 20 is seated on an internal shoulder of the flange 18 and is screwed to the flange 18 there. The gearbox 10 can be hydraulically actuated by means of the hydraulics control module 20 arranged in the interior of the gearbox housing 12 . Instead of hydraulic actuation, an electromechanical actuation system may also be used for the gearbox.
[0037] At an external shoulder of the flange 18 , a gearbox control module 22 is seated on the flange 18 and is screwed to the flange 18 there.
[0038] The gearbox control module 22 comprises a carrier plate into which there is integrated a gearbox plug connector 26 , and on the inner side 28 of which there is mounted an electronics component (TCU) 30 . arranged in the interior of the gearbox housing.
[0039] The gearbox plug connector 26 is led through a cutout or opening in the carrier plate 24 and is installed on the carrier plate 24 by means of a sealing ring 32 such that the opening is closed off in an oil-impermeable manner. By means of the gearbox plug connector 26 , the gearbox control module 22 can be electrically connected to a wiring loom of the vehicle in which the gearbox 10 is installed.
[0040] The electronics component 30 and an electrical connection means 34 with electrical lines 34 are mounted on the inner side 28 of the gearbox control module 22 . A sensor 36 and an intermediate plug connector may also be mounted there. The sensor 36 projects through an opening 38 in the gearbox housing 12 , through which opening electrical lines can also be led into the interior of the gearbox 10 , and which opening is surrounded by the flange 18 .
[0041] On the inner side of the gearbox control module 22 , there may also be mounted on the gearbox control module 22 an intermediate plug connector, for connecting to an electrical line in the interior of the gearbox 10 , and an actuator contact, for connecting to an actuator of the gearbox 10 .
[0042] Components, such as for example the components 20 , 30 , 34 , 36 , in the gearbox interior 14 are situated entirely or partially directly in the gearbox oil (ATF) and may be exposed to the temperatures (−40 . . . +150° C.) that prevail in the gearbox 10 . Components outside the gearbox 10 in the engine bay 16 may be exposed to temperatures of up to approximately 120° C. An outer surface 40 of the carrier plate 24 can thus serve as a cooling surface for the gearbox control module 22 . For better heat conduction, the electronics component is connected in thermally conductive fashion to the carrier plate 24 and can be cooled by the latter.
[0043] FIG. 2 shows a gearbox control module 22 in which the electrical connections 34 are integrated into the carrier plate 24 . The gearbox plug connector 26 and the electronics component 30 are cast into the carrier plate 24 .
[0044] FIG. 3 shows a gearbox control module 22 , on the outer side 40 of which there is mounted a motor control component 42 which comprises actuation components for an electric motor of the gearbox 10 . For the actuation of the motor, an input filter, and also a B6 bridge in the case of an EC motor, are required. The input filter is composed of capacitors, coils and field-effect transistors.
[0045] It is additionally pointed out that the expression “comprising” does not exclude other elements or steps, and the expressions “a” or “an” do not exclude a multiplicity. Furthermore, it is pointed out that features or steps that have been described with reference to one of the above exemplary embodiments may also be used in combination with other features or steps of other exemplary embodiments described above. Reference signs in the claims are not to be regarded as being restrictive. | A gearbox control module for a gearbox comprises an electronic component with an electronic circuit configured to control the gearbox, electrical connections and a module carrier. The electronics component and the electrical connections are mounted on the module carrier, and the module carrier is a cover configured to sealingly close off an interior of the gearbox. | 8 |
The present invention relates to a door/doorway system adapted to significantly reduce or eliminate the occurrence of sentinel events in medical facilities. Specifically, the invention is directed to a door having a particular construction that enables patient privacy but that still reduces or eliminates the physical means for a patient to hang him/herself.
BACKGROUND OF THE INVENTION
Numerous medical facilities are directed full or part time to patients at risk for committing suicide, specifically, by hanging. These suicides, referred to in the industry as sentinel events, often occur in the bathroom of the medical facility were a patient is able to have some privacy. Showerheads, curtain rods, bathroom hooks, and other bathroom hardware have all been converted to break-away devices or other tools to enable a patient to harm themselves or possibly commit suicide. A typical public bathroom may have stall partition walls. These stall partitions themselves pose a threat even if not dismantled. A further significant cause or facilitator of sentinel events is bathroom doors.
Public use bathrooms typically include bathrooms stalls. These stalls include partitions that use bars for rigidity. But even if partitions are removed and replaced with solid walls, or in any bathroom having a door, the doors themselves can be used as a platform or location for holding a belt or a piece of clothing. Inherently, every bathroom on a unit cannot be watched at the same time without enormous staff resources. Therefore, bathrooms, and specifically bathroom doors, provide an area of opportunity for a sentinel event for patients at risk for suicide. To date, the problems of sentinel events in bathrooms are typically addressed by removing all stall hardware and doors. While this reduces opportunities for sentinel events, it likewise eliminates all privacy that a patient may have.
SUMMARY
Accordingly, it is an object of the present invention to overcome the foregoing drawbacks and address the problems described above. The bathroom door described herein has been engineered so that any attempt to use it as a hanging platform will fail. Nothing can hang off the door or be wedged between the door and the doorway without sliding off or falling, because all foreseeable hanging points are removed.
In one example, a sentinel event reduction door comprises a trapezoidally-shaped panel comprising four sides. A continuous hinge is connected to the panel along substantially the full length of a first side thereof. The first side defines a substantially straight line. A second side of the panel adjacent the first side defines a substantially straight line, wherein the angle defined by the intersection of the first and second sides of the panel is an acute angle, and a third side of the panel, substantially parallel to and on the opposite angle. A third side of the panel, substantially parallel to and on the opposite side of panel from the first side, comprises a pliable material attached thereto.
In another alternative, a sentinel event reduction system comprises a door frame defining a door way, and a door hung on the door frame. The door comprises a trapezoidally-shaped panel comprising four sides. A continuous hinge is connected to the panel along substantially the full length of a first side thereof, the first side defining a substantially straight line. A top side of the panel is adjacent the first side, the top side defining a substantially straight line. The angle defined by the intersection of the first and top sides of the panel is an acute angle. The door way has a length and width that are larger than the greatest length and width defined by the door panel, and further wherein openings are defined by the top of the door and the door frame and by the bottom of the door and the door frame.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a sentinel event reduction system in which the door is shown in an open position.
FIG. 2 is a side elevation view of a sentinel event reduction system showing the door in the closed position.
DETAILED DESCRIPTION
In general terms, a sentinel event reduction system is described herein. The system includes a uniquely-engineered door that is hung in a door frame for use particularly in facilities where there are at risk patients who may hurt themselves or attempt suicide. The door is hung in any conventional door frame. The door has an angled top and a continuous hinge. Further, in at least some examples, a pliable material is attached to the opposite side of the door from the hinge side of the door. The door is dimensioned so that there are substantial openings above and below the door between the door and the door frame.
Turning now to FIGS. 1 and 2 , the sentinel event reduction system 10 is shown with a door 20 mounted onto one side of a door frame 15 . The complete doorway is defined by the door frame 15 and the floor 17 . The door 20 is trapezoidally-shaped. A first side of the door 25 is adjacent to and hanging on the door frame 15 . The first side 25 includes a continuous hinge 26 that attaches the door 20 onto the door frame 15 . This first side 25 of the door 20 is substantially straight to enable the operation of a conventional hinge along substantially the entire length of the first side.
A second or top side 30 of the door 20 is adjacent the first side 25 . An acute angle 31 is formed by the intersection of the first side 25 and top side 30 of the door 20 . The size of the acute angle 31 is, in one example, between about 45° and 65°. In one example, the acute angle is about 55°. Functionally, it is important that this acute angle 31 create such a slope on the top side 30 of the door 20 as to not allow anything to hang from it without sliding off. The door 20 is made of one or more panel components, and it may be made of any available materials such as metal, wood or plastic, or composites thereof. The functionality of the acute angle 31 may be enhanced with a door material having a low coefficient of friction such as Formica, metal or other smooth polymer material. Also, this top side 30 may be beveled or rounded (as shown in FIG. 1 ) to enhance the functionality of making it difficult to hang anything on it. The top side 30 is shown in the figures as being substantially straight. Prominent curves along the top side 30 may create flat portions or sections (at least substantially parallel with the floor) that could form a hanging point. Realistically, the top 30 of the door 20 may include some minimal curvature as long as it is sloped across the width of the door so that there is no creation of a hanging point, and the term “substantially straight line” to describe the top side includes slight curvatures.
The third side 35 of the door 20 is opposite the first side 25 . The third side 35 is generally parallel to the first side 25 to fit into a conventional, rectangular doorway. The width of the door 20 is less than the width of the doorway so that nothing may be jammed by a patient between the door frame 15 and the third side 35 to form a hanging point. In one example there is at least about a three inch gap between the door frame 15 and the third side 35 . To enhance the privacy for a patient or user, it is possible to attach a pliable material 36 along the length of the third side 35 . This pliable material 36 creates privacy along that gap between the third side 35 and the door frame 15 . However, the pliable material 36 is soft enough that a patient cannot use it as a wedge for creating a hanging point. The pliable 36 material may be a rubber gasket, as shown, or it may be brush material or anything pliable and soft.
The fourth side 38 of the door 20 is the bottom of the door and is shown as perpendicular to the first and third sides, 25 and 35 respectively, and is generally parallel to floor 17 . The fourth side 38 is shown as a straight line. This fourth side 38 may be any line that does not facilitate the opportunity for a sentinel event or otherwise formation of a hanging point. Like the tope side 30 , the fourth side 38 may be beveled or rounded to enhance the functionality of making it difficult to look anything on it.
There is no hardware shown in the sentinel event reduction system 10 other than the continuous hinge 26 and the screws 37 that attach the gasket 36 to the third side 35 . The use of a door handle presents an opportunity for creating a hanging point. If any additional hardware is desired then it must not create any opportunity for formation of a hanging point.
As shown, the doorway defined by the door frame 15 and floor 17 is a conventional rectangular shape. Alternatively, there could be a rounded top or other angled components that make up the doorway. Functionally, it is important that the doorway defined by the door frame 15 and floor 17 is wider and higher than a door as discussed herein. When door 20 is mounted in the door way, openings 40 and 45 are defined below and above the door. These openings 40 and 45 prevent a patient from stuffing a belt, sheet, clothing, shoestring, etc. above or below the door in order to create a hanging point. The top opening 45 is, in one example, at least about 12 inches in height across the entire width of the doorway. As shown, the top opening 45 has a narrowest point where the first side 25 of the door 20 is mounted onto the frame 15 . This height is at least about twelve inches, and obviously the height of the opening 45 increases when moving across the width of the door 20 . The bottom opening 40 is at least about six inches in height across its width as shown in the figures.
The door and system described herein can be part of an overall sentinel event plan that may be instituted. In order to reduce the opportunities for a sentinel event, the door described herein may be installed in place of other conventional door constructions. At the same time, rather than removing a door all together, the door described herein preserves the privacy and dignity of a patient when using a bathroom.
While the invention has been described with reference to specific embodiments thereof, it will be understood that numerous variations, modifications and additional embodiments are possible, and all such variations, modifications, and embodiments are to be regarded as being within the spirit and scope of the invention. | A sentinel event reduction door comprises a trapezoidally-shaped panel comprising four sides. A continuous hinge is connected to the panel along substantially the full length of a first side thereof. A second side of the panel is adjacent to the first side, wherein the angle defined by the intersection of the first and second sides of the panel is an acute angle. A third side of the panel, the side opposite the side of the panel from the first side, may comprise a pliable material attached thereto. | 4 |
FIELD OF THE INVENTION
[0001] The present invention relates to precipitation hardening copper alloys, and in particular, to Cu—Ni—Si—Cr system alloys suitable for use in components for various electronic devices.
BACKGROUND OF THE INVENTION
[0002] Copper alloys for electronic materials used in components for various electronic devices such as lead frames, connectors, pins, terminals, relays, and switches must satisfy both high strength and high electrical conductivity (or high thermal conductivity) as basic characteristics. Recent rapid advances of high integration and reductions in size and thickness of electronic components have accelerated requirements for higher performances of copper alloys used in components for electronic devices.
[0003] In recent years, in consideration of high strength and high electrical conductivity of copper alloys for electronic materials, the use of precipitation hardening copper alloys has increased, in place of traditional solid solution strengthened copper alloys such as phosphor bronze and brass. In the precipitation hardening copper alloys, age hardening of supersaturated solid solution after solution treatment facilitates uniform dispersion of fine precipitates and thus an increase in strength of the alloys. It also leads to a decrease in amount of solute elements in copper matrix and thus an improvement in electrical conductivity. The resulting materials have superior mechanical properties such as strength and spring properties, as well as high electrical and thermal conductivities.
[0004] Among precipitation hardening copper alloys, Cu—Ni—Si copper alloys known as Corson alloys are typical copper alloys having compatibility of relatively high electrical conductivity and strength, proper stress relaxation, and excellent bendability. Corson alloys are now being actively developed in the industry. In such copper alloys, fine particles of a NiSi intermetallic compound are precipitated in a copper matrix, thereby improving strength and electrical conductivity.
[0005] The precipitation of a NiSi intermetallic compound generally has a stoichiometric composition. For example, Japanese Unexamined Patent Application Publication No. 2001-207229 discloses that satisfactory electrical conductivity is achieved by bringing the mass ratio Ni/Si in an alloy close to the mass composition ratio of the intermetallic compound Ni 2 Si [(Ni atomic weight)×2/(Si atomic weight)×1)], i.e. a weight concentration ratio of Ni/Si in the range of 3 to 7.
[0006] Although characteristics may be improved by bringing the mass ratio Ni/Si close to the mass composition ratio of the intermetallic compound Ni 2 Si [(Ni atomic weight)×2/(Si atomic weight×1)] as mentioned in Japanese Unexamined Patent Application Publication No. 2001-207229, the presence of an excess amount of Si leads to some reductions in electrical conductivity. A possible countermeasure to increase the electrical conductivity is addition of elements that form compounds with excess Si. Cr is one of these elements, and forms Cr-containing Cu—Ni—Si system alloys.
[0007] Examples of the Cu—Ni—Si system alloys containing Cr as an alloy element are disclosed in Japanese Patent Nos. 2862942 and 3049137. Japanese Patent No. 2862942 discloses a method of heat treatment of a Corson alloy containing 1.5-4.0% by weight of Ni, 0.35-1.0% by weight of Si, optionally 0.05-1.0% by weight of at least one metal selected from the group consisting of Zr, Cr, and Sn, and the balance being Cu and incidental impurities, wherein the Corson alloy is heated (or cooled) in the temperature range of 400 to 800° C., so as to reduce the tensile thermal strain of the Corson alloy to a level not exceeding 1×10 −4 . The patent states that the method can prevent an ingot from cracking during the heat treatment.
[0008] Japanese Patent No. 3049137 discloses a high strength copper alloy containing 2-5% by weight of Ni, 0.5-1.5% by weight of Si, 0.1-2% by weight of Zn, 0.01-0.1% by weight of Mn, 0.001-0.1% by weight of Cr, 0.001-0.15% by weight of Al, 0.05-2% by weight of Co, not more than 15 ppm of S as an impurity, and the balance being Cu and incidental impurities. This copper alloy exhibits excellent bendability. This patent states that Cr is an element which reinforces grain boundaries in an ingot and leads to an improvement in hot workability. It also states that a Cr content exceeding 0.1% by weight causes oxidation of molten metal and poor casting performance. In addition, it states that the copper alloy is covered with charcoal in a cryptol furnace to be melted and cast in the atmosphere.
[0009] A compound of Cr and Si is disclosed in Japanese Unexamined Patent Application Publication No. 2005-113180. This patent refers to the hot working temperature and heat treatment temperature for age hardening of an ingot of a copper alloy having excellent etching and punching workability for electronic devices. The copper alloy contains 0.1-0.25% by weight of Cr, 0.005-0.1% by weight of Si, 0.1-0.5% by weight of Zn, 0.05-0.5% by weight of Sn, and the balance being Cu and incidental impurities, wherein the weight ratio Cr/Si is in the range of 3 to 25, particles of Cr—Si compounds having a size of 0.05 μm to 10 μm are present in a number density of 1×10 3 to 5×10 5 /mm 2 in the copper matrix while particles of Cr compounds (other than the Cr—Si compound) having a size greater than 10 μm are not present. According to this method, both etching and punching workability are preferably available.
SUMMARY OF THE INVENTION
[0010] Rapid advances of high integration and reductions in size and thickness of electronic components in recent years have also placed a requirement on Cr-containing Cu—Ni—Si system alloys to have significantly improved performance. In Japanese Unexamined Patent Application Publication No. 2001-207229, Cr is not added and the excess Ni and Si actually reduce electrical conductivity in some degree. This means the significant progress in performance is unfulfilled yet. Although Cr is added in Cu—Ni—Si system alloys in Japanese Patent Nos. 2862942 and 3049137, it is added for solid solution hardening in Japanese Patent No. 2862942 and for an improvement in hot workability in Japanese Patent No. 3049137. No description of Cr—Si compounds, which is a key component of the present invention, is found in these documents. Accordingly, these patent documents do not suggest the solution achieved by the present invention.
[0011] Although Japanese Unexamined Patent Application Publication No. 2005-113180 discloses that etching and punching workabilities are improved by controlling the number density and size of the Cr—Si compounds, consideration is focused on the conditions for the formation of the Cr—Si compounds and no consideration is paid for the formation of NiSi compounds because no Ni is added. Accordingly, Japanese Unexamined Patent Application Publication No. 2005-113180 also does not suggest the solution achieved by the present invention.
[0012] An object of the present invention is to provide a Corson alloy having significantly improved characteristics, i.e. high strength and high electrical conductivity, by enhancing the effect of Cr contained in a Cu—Ni—Si system alloy.
[0013] Through extensive research for solving the problem, the inventors have accomplished an invention as described below. In a Cu—Ni—Si system alloy, the Si content is in excess of the Ni content so that nickel silicide is surely precipitated from the contained Ni in order to improve the strength, while the excess Si is combined with the contained Cr to achieve high conductivity of the alloy. The essence of the present invention is to control the excess growth of particles of Cr—Si compounds so as to prevent a shortage of Si, which combines with Ni. In particular, the inventors have found that the control of the temperature and cooling rate of the heat treatment can enhance such effects, through investigation on the preferred composition, size, and number density of particles of the Cr—Si compounds.
[0014] The present invention includes the following Aspects:
[0015] (1) A copper alloy for electronic materials, comprising 1.0-4.5% by mass Ni, 0.50-1.2% by mass Si, 0.003-0.3% by mass Cr (wherein the weight ratio of Ni to Si satisfies the expression: 3≦Ni/Si≦5.5), and the balance being Cu and incidental impurities, wherein particles of Cr—Si compounds having a size of 0.1 μm to 5 μm are dispersed in the alloy, the dispersed particles having an atomic concentration ratio of Cr to Si of 1 to 5 and a dispersion density of no more than 1×10 6 /mm 2 .
[0016] (2) The copper alloy for electronic materials according to Aspect (1), wherein the dispersion density of the particles of the Cr—Si compounds having a size of 0.1 μm to 5 μm is higher than 1×10 4 /mm 2 .
[0017] (3) The copper alloy for electronic materials according to Aspect (1) or (2), further comprising 0.05-2.0% by mass of at least one element selected from Sn and Zn.
[0018] (4) The copper alloy for electronic materials according to any one of Aspects (1) to (3), further comprising 0.001-2.0% by mass of at least one element selected from Mg, Mn, Ag, P, As, Sb, Be, B, Ti, Zr, Al, Co and Fe.
[0019] (5) A wrought copper product comprising the copper alloy according to any one of Aspects (1) to (4).
[0020] (6) A component for electronic devices, comprising the copper alloy according to any one of Aspects (1) to (4).
[0021] The present invention can provide the Corson copper alloy having significantly improved strength and electrical conductivity suitable for electronic materials due to the positive effect of Cr, which is an element contained in the alloy.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Amounts of Ni and Si to be Added
[0022] Ni and Si form nickel silicides (e.g. Ni 2 Si) as an intermetallic compound through suitable heat treatment, resulting in high strength without a decrease in conductivity. The mass ratio of Ni to Si is preferably close to the stoichiometric ratio as described above, i.e. 3≦Ni/Si≦5.5, more preferably 3.5≦Ni/Si≦5.0.
[0023] However, even if the ratio Ni/Si is within the range, desired strength is not achieved at a Si content of less than 0.5% by mass. Furthermore, a Si content of more than 1.2% by mass is not preferred because of significantly reduced conductivity and poor hot workability due to formation of a liquid phase in a segregation region, despite enhanced strength. As a result, the preferred Si content is in the range of 0.5% to 1.2% by mass, preferably 0.5% to 0.8% by mass. The amount of Ni to be added may be determined so as to satisfy the preferable ratio described above. In view of balance with the Si content, the suitable Ni content is in the range of 2.5% to 4.5% by mass, preferably 3.2% to 4.2% by mass, more preferably 3.5% to 4.0% by mass.
Amount of Cr to be Added
[0024] In general Cu—Ni—Si system alloys, increased concentrations of Ni and Si raise the total number of precipitated particles, and thus enhance strength through precipitation strengthening. Such increased concentrations, however, are accompanied by an increased amount of solid solution that does not contribute to precipitation. This causes a reduction in conductivity at a maximum strength, regardless of an increase in the maximum strength after age precipitation. In this regard, when 0.003% to 0.3% by mass of, preferably 0.01% to 0.1% by mass of Cr is added to the Cu—Ni—Si system alloy, higher conductivity can be achieved without a reduction in strength compared to a Cu—Ni—Si system alloy having the same Ni—Si concentrations. Furthermore, a higher yield can be achieved due to improved hot workability.
[0025] Regarding the composition of particles precipitated in the Cr-containing Cu—Ni—Si system alloy, particles primarily composed of elemental Cr having a bcc structure are readily precipitated as well as particles of Cr—Si compounds. Since Cr can easily precipitate chromium silicides (e.g. Cr 3 Si) in the copper matrix through proper heat treatment, the dissolved Si component, which has not precipitated in the form such as Ni 2 Si during a combined process of solution treatment, cold rolling and aging, can be precipitated as Cr—Si compounds. This process can suppress a reduction in conductivity caused by the dissolved Si and thus achieve high conductivity without a reduction in strength.
[0026] A low concentration of Si in Cr particles leads to residual Si in the matrix, resulting in a reduction in conductivity. On the other hand, a high concentration of Si in Cr particles causes a decreased concentration of Si contributing to precipitation of particles of a NiSi compound, resulting in a reduction in strength. Furthermore, a high concentration of Si in Cr particles accelerates formation of coarse Cr—Si particles, resulting in decreases in bendability and fatigue strength. Moreover, a lower cooling rate after solution treatment and excess heating treatment for aging cause coarsening of particles of the Cr—Si compounds. This causes a decrease in Si concentration necessary for formation of a NiSi compound and thus precludes the formation of a NiSi compound contributing to strength. This is because diffusion rates in Cu of Si and Cr are higher than that of Ni, which accelerates coarsening of particles of the Cr—Si compounds. The precipitation rate of Cr—Si compounds is thus higher than that of NiSi compounds.
[0027] The composition, size and density of particles of the Cr—Si compounds can, therefore, be controlled by regulating the cooling rate after solution treatment and avoiding severer aging conditions such as higher temperature and longer time than the optimum conditions for maximum strength. Consequently, the Cr concentration should be 0.003% by mass to 0.3% by mass, and the atomic ratio of Cr to Si in Cr—Si compounds should be in the range of 1 to 5.
[0028] Since Cr is preferentially precipitated at crystal grain boundaries in the cooling process after melting and casting, it can strengthen the grain boundaries. As a result, cracking during hot working can be reduced, and thus a high yield can be achieved. Although Cr precipitated at grain boundaries after melting and casting is redissolved during the solution treatment, it forms silicides during the subsequent age precipitation process. In general Cu—Ni—Si system alloys, part of the added Si does not contribute to age precipitation and remains dissolved in the matrix, obstructing an increase in conductivity. Since the addition of Cr, which is an element to form silicides, leads to further precipitation of silicides and a reduction in dissolved Si, the conductivity can be increased without a reduction in strength, compared to conventional Cu—Ni—Si system alloys.
Size and Dispersion Density of Particles of Cr—Si Compounds
[0029] The size of particles of the Cr—Si compounds has an effect on bendability and fatigue strength. When the particles of the Cr—Si compounds have a size of greater than 5 μm or when the dispersion density of particles of the Cr—Si compounds having a size in the range of 0.1 to 5 μm exceeds 1×10 6 /mm 2 , the bendability and the fatigue strength are significantly reduced. Furthermore, since the number density has an effect on the excess and deficiency of the concentration of Si in the matrix, the presence of large particles dispersed in large quantities will become an obstacle to the desired strength. Consequently, the upper limit of the dispersion density is 1×10 6 /mm 2 , preferably 5×10 5 /mm 2 , more preferably 1×10 5 /mm 2 . In addition, it is preferred that the density be more than 1×10 4 /mm 2 , in order to achieve the significant effect of the addition of Cr.
Sn and Zn
[0030] Addition of at least one element selected from Sn and Zn in a total amount of 0.05-2.0% by mass to the Cu—Ni—Si system alloy of the present invention can improve stress relaxation and other characteristics without significant reductions in strength and conductivity. An amount of less than 0.05% by mass leads to insufficient effect of addition. On the other hand, an amount of more than 2.0% by mass causes poor production characteristics such as castability and hot workability and low conductivity of the products. It is therefore preferred that the amount of these elements should be added from 0.05% by mass to 2.0% by mass.
Other Elements to be Added
[0031] Addition of appropriate amounts of Mg, Mn, Ag, P, As, Sb, Be, B, Ti, Zr, Al, Co and Fe brings about various effects that are complementary to each other, for example, enhanced strength and conductivity, and improved production characteristics such as bendability, plating property, and hot workability of an ingot due to the formation of a fine microstructure. Accordingly, at least one element selected from these elements may be added as necessary in a total amount of 2.0% by mass or less to the Cu—Ni—Si system alloy of the present invention, to meet required properties. An amount of less than 0.001% by mass cannot achieve the desired effects. On the other hand, an amount of more than 2.0% by mass causes a significant decrease in conductivity and poor production characteristics. Accordingly, the total amount of the elements to be added is preferably 0.001 to 2.0% by mass, more preferably 0.01 to 1.0% by mass. Incidentally, elements not specified in this specification may be added in a range causing no negative effect on the characteristics of the Cu—Ni—Si system alloy of the present invention.
[0032] The method of producing alloys of the present invention is described below. The Cu—Ni—Si system alloy of the present invention can be produced by any conventional method, except for conditions of solution treatment and aging treatment for control of Ni—Si compounds and Cr—Si compounds. Although no specific explanation would be necessary for those skilled in the art who can select an optimal method depending on the composition and required properties, a typical method is described below for illustrative purposes.
[0033] First, raw materials such as electrolytic copper, Ni, Si, and Cr are melted in a melting furnace in atmosphere to obtain molten metal having a desired composition. Next, this molten metal is cast into an ingot. Through subsequent hot-rolling and repeated processes of cold-rolling and heat treatment, strips and foils having a desired thickness and properties are formed. The heat treatment includes solution treatment and aging treatment. In the solution treatment, the Ni—Si compounds and the Cr—Si compounds are dissolved into the copper matrix while the copper matrix is recrystallized at the same time, during heating at a high temperature of 700 to 1000° C. The hot rolling may combine with the solution treatment.
[0034] The important factors in the solution treatment are a heating temperature and a cooling rate. In conventional methods, the cooling rate after heating was not controlled, and water-cooling using a water tank provided at a furnace outlet or air-cooling in the atmosphere was employed. In that case, the cooling rate easily varied depending on the set heating temperature. The conventional cooling rate varied in a wide range of 1° C./s or less to 10° C./s or more. Consequently, in the conventional cooling, it was difficult to control properties of alloys, such as an alloy of the present invention.
[0035] Preferably the cooling rate is in the range of 1° C./s to 10° C./s. In aging treatment, the Ni—Si compounds and the Cr—Si compounds dissolved during the solution treatment are precipitated as fine particles by heating at a temperature in the range of 350 to 550° C. for at least 1 hour, typically for 3 to 24 hours. The strength and conductivity increases through the aging treatment. Before and/or after the aging, cold-rolling may be employed for higher strength. When the cold-rolling is performed after the aging treatment, stress relief annealing (annealing at low temperature) may be performed after the cold-rolling.
[0036] In one embodiment, the Cu—Ni—Si copper alloy of the present invention may have a 0.2% yield strength of not less than 780 MPa and a conductivity of not less than 45% IACS; may further have a 0.2% yield strength of not less than 860 MPa and a conductivity of not less than 43% IACS; or may still further have a 0.2% yield strength of not less than 890 MPa and a conductivity of not less than 40% IACS.
[0037] The Cu—Ni—Si system alloy of the present invention can be shaped into various wrought copper products such as strips, ribbons, pipes, rods and bars. Furthermore, the Cu—Ni—Si system alloy of the present invention can be used in components for electronic devices such as lead frames, connectors, pins, terminals, relays, switches and foils for secondary batteries, which require both high strength and high electrical conductivity (or thermal conductivity).
EXAMPLES
[0038] The following examples are merely illustrative for further understanding of the present invention and its advantages, and not limiting to the disclosure in any way.
[0039] The copper alloys used in Examples of the present invention are copper alloys containing various amounts of Ni, Si and Cr and further containing optional Sn, Zn, Mg, Mn, Co and Ag, as shown in Table 1. The copper alloys used in Comparative Examples are Cu—Ni—Si copper alloys having parameters out of the range of the present invention.
[0040] The copper alloys having various compositions described in Table 1 were melted in a high-frequency melting furnace at 1300° C. and each alloy was cast into an ingot having a thickness of 30 mm. Next, this ingot was heated to 1000° C., then was hot-rolled into a plate having a thickness of 10 mm, and was cooled immediately. After the plate was planed for removal of scales to a thickness of 8 mm, it was cold-rolled into a thickness of 0.2 mm. Subsequently, solution treatment was conducted in argon gas atmosphere at a temperature of 800 to 900° C. for 120 seconds, depending on the addition amount of Ni and Cr, followed by cooling down to room temperature at various cooling rates. The cooling rate was controlled by varying the flow rate of gas blowing against the sample. The cooling rate was determined by the measurement of the time required for the sample to be cooled from its attained maximum temperature to 400° C. The cooling rate of the furnace without gas blow was 5° C./s, and the lower cooling rate was set at 1° C./s in the case of cooling along with controlled heating output. After this, the plate was cold-rolled into a thickness of 0.1 mm, and was finally aged in inert atmosphere at 400 to 550° C. for 1 to 12 hours depending on the amount of added elements, thereby samples were produced.
[0041] The strength and conductivity of each alloy produced as described above were evaluated. The strength was evaluated by 0.2% yield strength (YS; MPa) measured by a tensile test in the direction of rolling. The electric conductivity (EC; % IACS) was determined from the volume electrical resistivity measured by double bridges. The bendability was evaluated by W bend test using a W-shaped mold at a ratio of the bending radius to the thickness of the sample plate of 1. The evaluation was performed through observation of the bent surface with an optical microscope. For samples where no crack was observed, Rank A was given indicating a satisfactory level in practical use. For samples any crack was observed, Rank F was given. In a fatigue test, symmetrically reversed stress load according to JIS Z 2273 was loaded to determine the fatigue strength (MPa) where the alloy was broken at 10 7 cycles.
[0042] For observation of particles of the Cr—Si compounds by FE-AES, a plate surface of the samples was electropolished. Particles having a size of not smaller than 0.1 μm were observed at many places. Adsorbed elements (C and O) on the surface layer were removed by Ar + sputtering. Auger spectra of individual particles were measured and the weight concentrations of detected elements were determined by semiquantitative analysis using sensitivity coefficients. Particles containing the detected Cr and Si were extracted as objects. The composition (Cr/Si), size, and dispersion density of particles of the Cr—Si compounds were respectively defined as the average Cr/Si ratio, the minimum inside diameter, and the average number in each observation view for the particles of the Cr—Si compounds having a size of 0.1 to 5 μm analyzed at many places by FE-AES observation. The results are shown in Tables 1 and 2.
[0000]
TABLE 1
Solution
Mg, Mn, Ag, P,
treatment
Cooling
Aging
As, Sb, Be, B,
temperature
rate
temperature
Ni
Si
Cr
Sn
Zn
Ti, Zr, Al, Co, Fe
(° C. × 120 s)
(° C./s)
(° C.)
Examples
1
2.7
0.6
0.005
800
1
450
2
2.7
0.6
0.05
800
2
450
3
2.7
0.6
0.05
800
4
450
4
2.7
0.6
0.05
800
8
450
5
2.7
0.6
0.05
800
2
400
6
2.7
0.6
0.05
800
2
500
7
2.7
0.6
0.1
800
4
450
8-1
2.7
0.6
0.05
0.1Mg
800
4
450
8-2
2.7
0.6
0.05
1.0Co
800
4
450
8-3
2.7
0.6
0.05
1.0Co, 0.1Mg
800
4
450
9
2.7
0.6
0.05
0.1Mn
800
4
450
10
2.7
0.6
0.05
0.3
800
4
450
11
2.7
0.6
0.05
0.3
0.1Ag
800
4
450
12
2.7
0.6
0.05
0.3
0.5
800
4
450
13
2.7
0.6
0.05
0.3
0.5
0.1Mg
800
4
450
14
4.0
0.9
0.005
900
2
450
15
4.0
0.9
0.05
900
3
450
16
4.0
0.9
0.05
900
6
450
17
4.0
0.9
0.05
900
9
450
18
4.0
0.9
0.05
900
3
400
19
4.0
0.9
0.05
900
3
500
20
4.0
0.9
0.1
900
6
450
21
4.0
0.9
0.17
900
7
450
22
4.0
0.9
0.05
0.2Mg
900
3
450
23
4.0
0.9
0.05
0.1Mn
900
3
450
24
4.0
0.9
0.05
0.3
900
3
450
25
4.0
0.9
0.05
0.3
0.1Ag
900
3
450
Dispersion
Composition
Aging
density of CrSi
of CrSi
time
particles
particles
Yield
Electrical
Bend-
Fatigue
(h)
(×10 5 /mm 2 )
(Cr/Si)
Strength
Conductivity
ability
Strength
Examples
1
6
0.3
4
760
48
A
275
2
6
0.5
3
765
48
A
280
3
6
0.4
3
765
48
A
280
4
6
0.2
3
765
47
A
280
5
12
0.5
3
770
47
A
280
6
2
0.5
3
770
47
A
280
7
6
1
2
770
46
A
285
8-1
6
0.5
3
785
46
A
285
8-2
6
0.5
3
790
48
A
285
8-3
6
0.5
3
800
47
A
285
9
6
0.5
3
785
46
A
285
10
6
0.5
3
785
46
A
285
11
6
0.5
3
785
46
A
285
12
6
0.5
3
785
45
A
285
13
6
0.5
3
800
45
A
285
14
4
0.7
4
860
44
A
300
15
4
1.1
3
870
43
A
300
16
4
0.8
3
870
43
A
300
17
4
0.4
3
870
43
A
300
18
10
1.1
3
870
43
A
300
19
2
1.1
3
870
43
A
300
20
4
2.2
2
870
44
A
300
21
4
5.6
2
875
43
A
300
22
4
1.1
3
890
41
A
325
23
4
1.1
3
890
41
A
325
24
4
1.1
3
890
41
A
325
25
4
1.1
3
890
41
A
325
Composition: % by mass
[0000]
TABLE 2
Solution
Mg, Mn, Ag, P,
treatment
Cooling
Aging
As, Sb, Be, B,
temperature
rate
temperature
Ni
Si
Cr
Sn
Zn
Ti, Zr, Al, Co, Fe
(° C. × 120 s)
(° C./s)
(° C.)
Comparative
1
2.7
0.6
0.05
800
0.5
450
examples
2
2.7
0.6
0.1
800
0.5
450
3
4.0
0.9
0.05
900
0.5
450
4
2.7
0.6
0.05
800
15
450
5
2.7
0.6
0.1
800
15
450
6
2.7
0.6
0.05
800
4
600
7
4.0
0.9
0.05
900
5
600
8
2.7
0.6
0.5
800
4
450
9
4.0
0.9
0.5
900
6
450
Dispersion
Composition
Aging
density of CrSi
of CrSi
time
particles
particles
Yield
Electrical
Bend-
Fatigue
(h)
(×10 5 /mm 2 )
(Cr/Si)
Strength
Conductivity
ability
Strength
Comparative
1
6
15
3
700
51
F
225
examples
2
6
20
3
720
49
F
230
3
6
25
3
820
43
F
270
4
6
0.05
20
740
43
A
240
5
6
0.1
25
750
43
A
240
6
6
20
7
680
53
F
200
7
6
25
8
780
44
F
250
8
6
14
3
710
51
F
230
9
4
18
3
810
44
F
270
Composition: % by mass
[0043] Examples 1 to 25 of the present invention show satisfactory properties, since particles of Cr—Si compounds have a dispersion density of no more than 1×10 6 and a Cr/Si ratio in the range of 1 to 5 due to a proper cooling rate. In contrast, Comparative Examples 1 to 3 show insufficient strength and poor bendability due to excess grow of particles of Cr—Si compounds caused by a slow cooling rate. Comparative Examples 4 and 5 show poor strength and conductivity due to insufficient grow of the particles and excess Si dissolved in the alloy caused by a rapid cooling rate. Comparative Examples 6 and 7 show insufficient strength and poor bendability due to excess grow of particles of Cr—Si compounds caused by a high aging temperature. Comparative Examples 8 and 9 show poor strength and poor bendability due to excess grow of particles of Cr—Si compounds caused by an excess concentration of Cr. | An object of the present invention is to provide a Corson alloy having significantly improved characteristics, i.e. high strength and high electrical conductivity, by enhancing the effect of addition of Cr to a Cu—Ni—Si system alloy. There is provided a copper alloy for electronic materials comprising 1.0-4.5% by mass Ni, 0.50-1.2% by mass Si, 0.003-0.3% by mass Cr wherein the weight ratio of Ni to Si satisfies the expression: 3≦Ni/Si≦5.5, and the balance being Cu and incidental impurities, wherein particles of Cr—Si compounds having a size of 0.1 μm to 5 μm are dispersed in the alloy and the dispersed particles having an atomic concentration ratio of Cr to Si of 1 to 5 and a dispersion density of no more than 1×10 6 /mm 2 . | 2 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This is a continuation patent application of U.S. patent application Ser. No. 11/173,207, filed Jul. 1, 2005, which claims the benefit of an earlier filing date from U.S. patent application Ser. No. 60/607,227, filed Sep. 3, 2004, the entire contents of which is incorporated herein by reference.
BACKGROUND
[0002] In the hydrocarbon exploration and recovery arts and other similar “downhole” arts, downhole tools are often “set” utilizing pressure from a pressure source such as a remote pump or a power charge. For example, a commercially available system from Baker Oil Tools, Houston, Tex. known as a “Baker E-4 pressure setting tool” with a firing head, utilizes a power charge. The power charge is ignited at an appropriate time. As the charge burns it creates expanding gas which is translated by a piston arrangement into either hydraulic fluid pressure for an inflatable or into mechanical energy to ratchet slips into place in a mechanical packer.
[0003] While the “E-4” product is quite capable of operating well, the power charge component thereof creates some difficulties with respect to transportation, importation and exportation due to varying laws regarding the transportation of “hazardous materials”. Because of these potential difficulties, it would be helpful to the industry to have a setting tool that operates similarly to the “E-4” tool but does not require the use of hazardous materials.
SUMMARY
[0004] Disclosed herein is a downhole tool actuation arrangement. The arrangement includes a housing having a chamber, at least one piston in operable communication with the chamber and at least one electrode exposed to the chamber. The electrodes are receptive to a power source.
[0005] Further disclosed is a method for actuating a downhole tool. The method includes discharging a voltage source through at least one electrode to cause a pressure wave in a fluid surrounding the at least one electrode and moving at least one piston in response to the pressure wave.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] Referring now to the drawings wherein like elements are numbered alike in the several Figures:
[0007] FIG. 1 is a schematic view of a pressure actuation component of a setting tool; and
[0008] FIG. 2 is a cross-sectional view of a focuser.
DETAILED DESCRIPTION
[0009] An actuation tool such as a setting tool having no need for a remote pressure source such as a surface hydraulic pump and reservoir or mechanical impact source, therefore runnable on wireline, and in addition not requiring a power charge, is realized by utilizing a submerged discharge electrical pressure source. Referring to FIG. 1 , one embodiment of an actuation or setting tool 10 is illustrated. A housing 12 is connected to a wireline by which the tool 10 is run and through which electrical energy is deliverable to the tool 10 . It is also to be understood that different power sources are also applicable such as seismic electric line, coil tubing with an electric feed, batteries, etc. Within housing 12 is a capacitor bank 14 . The capacitor bank 14 functions to store voltage for rapid release upon command. The stored voltage is delivered to and released through at least one electrode (if a suitable ground is available) or a pair of electrodes 16 (as illustrated) where an arc will be formed upon discharge of capacitor bank 14 . The electrodes 16 are immersed in a fluid 18 within a cavity 20 . In the illustrated embodiment a port 22 is provided for inflow of fluid from around the tool 10 . The fluid 18 in chamber 20 may be of many different chemical constitutions but commonly will be water or oil.
[0010] When triggered by a well operator, a downhole intelligent controller or even a simple switch configured to cause the discharge of the capacitor bank 14 at the appropriate time, an arc 24 forms between the two electrodes 16 . In the volume of fluid surround the arc 24 , an instantaneous vaporization (or other pressure creating modification) of the fluid takes place. The vaporization creates a pressure spike in the form of a shock wave that then propagates through the fluid 18 . When the shock wave encounters a material boundary such as housing 12 or a piston the energy of the shock wave is absorbed. Some of this energy (a device designed to focus the shockwave on the piston is disclosed hereinafter) is absorbed by the piston 26 causing the same to move in piston bore 28 . The amount of movement of the piston 26 is dependent upon the amplitude of the shockwave. Shockwave amplitude is directly proportional to the fluid 18 density and inversely proportional to the square of electric discharge duration. It should be noted that although FIG. 1 illustrates the piston 26 as an intermediary component utilized to compress a trapped fluid, piston 26 could be mechanically connected to the tool to be actuated, such arrangement foregoing the trapped fluid chamber.
[0011] In the embodiment illustrated in FIG. 1 , the piston 26 is a ratcheting piston. This arrangement is selected so that smaller amplitude shockwaves are useable by the actuation tool. The piston 26 includes ratchet teeth 30 , which engage a ratchet recess 32 . Through the ratchet arrangement, each shockwave (generated by capacitor discharge), causes an incremental movement of piston 26 , is cumulative in effect with respect to piston 26 because of the ratchet arrangement. The piston may only move in one direction; it is mechanically prevented from moving in the opposite direction. Thereby such is also cumulative with respect to a fluid 34 that is trapped in recess 32 between surface 36 of piston 26 and surface 38 of piston 40 . Fluid pressure on piston 40 (this could be one or more pistons that may be cylindrical and arranged annularly or may be annular pistons; the trapped fluid pressure is not bound to one piston) is utilized as is the power charge expansion fluid in the commercially available E-4.
[0012] In another embodiment, the ratchet teeth are not necessary as the frequency of discharge at the electrodes 16 is altered such that pressure in the fluid 18 accumulates at a rate similar to that of a power charge in the prior art E-4 device. More specifically, the discharge frequency is such that pressure generated in a discharge event is not dissipated as subsequent discharge events are occurring. The frequency of pulses is controlled to build and then maintain a substantially constant pressure. The exact time required to set a specific tool depends on a number of factors such as the complexity of the tool being set, the hydrostatic pressure in the immediate vicinity of the tool being set and the temperature of the well, especially in the vicinity of the tool being set. As the complexity of the tool increases, the setting time increases; as hydrostatic pressure increases, the setting time increases; and as temperature increases the setting (or actuation) time decreases. For example, time factors for setting tools might be about 5-10 seconds for more simple tools in easier-to-set conditions while more complex tools that might be in harder-to-set conditions could have a time factor to set of about 40-60 seconds. It is important to recognize that these are only examples and that other times to set could be applicable for certain situations or constructions. The pulse arrangement disclosed herein allows for adaptation to these variables in the field and on-the-fly. Therefore, much greater control and accuracy of the setting process is obtainable using the method and arrangement disclosed herein.
[0013] In each of the foregoing embodiments a focuser 50 (see FIG. 2 ), may be frustoconical or parabolic in configuration. The focuser 50 includes an opening 52 in a location calculated to release an incident pressure wave toward a target surface. The focuser 50 may be placed at the electrode discharge location to focus the resulting pressure wave. Such focusing is beneficial to functionality of the arrangement because where the pressure is focused on the piston, less of the pressure wave will be lost to non-functional portions of the arrangement.
[0014] It is also important to note that the arrangement as described herein allows for pressure generation to be started and stopped at will. This is beneficial in that it means a downhole tool may be partially set and then held in that position before being completed. For example, a setting sequence of a packer can be controlled; the packer can be set and allowed to stand for a period of time before being final set and released. Such control of the setting or other actuation process was not available with the prior art E-4 system. Control is advantageous in that it ensures a good set of the target tool.
[0015] The discharge may be controlled from a surface location or downhole location and may be remote or local. In one embodiment, control would be tighter through the incorporation of one or more sensors at the arrangement. Sensors might include pressure in the chamber 20 , movement in piston 26 or other of the employed pistons. In addition or substitutionally operational sensors in the tool being set to verify that it is in a particular condition may be employed.
[0016] While preferred embodiments have been shown and described, modifications and substitutions may be made thereto without departing from the spirit and scope of the invention. Accordingly, it is to be understood that the present invention has been described by way of illustrations and not limitation. | Disclosed herein is a downhole tool actuation arrangement. The arrangement includes a housing having a chamber, at least one piston in operable communication with the chamber and at least one electrode exposed to the chamber. The electrodes are receptive to a power source. Further disclosed is a method for actuating a downhole tool. The method includes discharging a voltage source through at least one electrode to cause a pressure wave in a fluid surrounding the at least one electrode and moving at least one piston in response to the pressure wave. | 4 |
This is a divisional of U.S. application Ser. No. 08/217,502 filed Mar. 24, 1994 now U.S. Pat. No. 5,554,100.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to endoscopic instrumentation, and, more particularly, to a disposable rigid arthroscope having a direction of view offset relative to the longitudinal axis of the arthroscope.
2. Description of the Prior Art
Endoscopes have long been used in surgery to view internal portions of a patient's body through a narrow incision in the body exterior or through a naturally occurring hollow viscus. Endoscopes are long, slender instruments having a shaft which is either rigid or flexible, depending upon the procedure being performed. In general, endoscopes include an objective lens positioned adjacent a distal end, and an image transmission system which may include a fiber optic bundle, relay rods or lenses, or a solid state sensor to transmit the image to the viewer. Endoscopes also are usually equipped with an illumination system, such as a fiber optic bundle, which illuminates the area being imaged. Generally, a camera adapter is provided at the proximal end of the endoscope to permit the image to be displayed on a monitor for viewing by the entire surgical team.
Most endoscopes used for medical procedures have a fixed forward viewing angle. Different areas of the body can be imaged by changing the position of the endoscope or, in the case of flexible endoscopes, by bending the distal tip. In these endoscopes, the objective lens is disposed perpendicular to the optical axis of the instrument such that the area directly in front of the instrument is viewed by the user.
Some endoscopes have a direction of view which is offset relative to the optical axis. Examples of endoscopes of this type are disclosed in U.S. Pat. Nos. 4,576,147 to Hashiguchi, 4,615,333 to Taguchi, 4,850,342 to Hashiguchi et al. and 5,184,602 to Anapliotis et al. Such endoscopes, sometimes referred to as inclined angle of view endoscopes, side viewing endoscopes or oblique angle of view endoscopes, make it possible to thoroughly examine interior body spaces, such as the lining of a body cavity, e.g., esophagus, intestinal walls and articular joint spaces, by rotating the instrument. Typically, these side viewing endoscopes incorporate an angle directing prism as part of its objective assembly to redirect the field of view relative to the optical axis. In accordance with the side viewing endoscope, the illuminating fiber optic bundle is typically orientated or bent at an appropriate angle at its light emitting distal end to direct light onto the field of view.
One type of endoscope which may incorporate inclined angle of view capability is an arthroscope. Arthroscopes are used to examine the interior structure of a body joint, for example, a knee, in order to determine the extent of damage to the joint. Arthroscopes are typically smaller in diameter than other types of endoscopes, such as laparoscopes, to enable the scope to fit into the relatively small joints of the bone, particularly the wrist and foot. Examples of arthroscopes are disclosed in U.S. Pat. Nos. 4,838,247 to Forkner, 5,188,093 to Lafferty et al. and 5,190,028 to Lafferty et al.
Known endoscopes and arthroscopes having an inclined direction of view such as the scopes disclosed in the aforementioned patents have their own particular shortcomings. For example, the construction of such endoscopes is typically costly, thereby precluding the economic feasibility that such scopes may be disposed after a single use. Furthermore, properly positioning and retaining the illuminating optical fibers in a manner such that the light emitting end portions of the fibers directly illuminate light in the perspective visual field direction often entails substantial modification to the endoscopic tube and/or the incorporation of adapters and/or attachments within the distal end of the scope,
U.S. Pat. No. 4,576,147 to Hashiguchi describer an endoscope with an inclined angle of view wherein a tip member, positioned within each of a lens carrying inner tube and an outer tube, and a saddle shaped pressing member, soldered to the tip member of the inner tube, cooperate to orientate the optical fiber end portions in the visual field direction. A disadvantage of the Hashiguchi '147 endoscope is that the additional components e.g., the tip members within each of the inner and outer tubes and the pressing member, need to be precisely manufactured in order to be incorporated within the endoscope, thus increasing the cost of the endoscope. Furthermore, such components require additional steps in the assembly of the Hashiguchi '747 endoscope, further increasing the cost of manufacture of the scope.
A further disadvantage with the construction of known endoscopes of the type having inclined angles of view concerns mounting the distal optical components within the distal end of the endoscope. For example, the endoscope described in U.S. Pat. No. 4,850,342 to Hashiguchi et al. incorporates several frame members which are fitted within the lens carrying inner tube to mount the objective prism and the objective lens components within the tube. The distal most cover glass of the Hashiguchi '342 endoscope is mounted via a housing member and a separate fastening ring which is fitted within an opening in the housing member.
Accordingly, it would be desirous to provide a disposable endoscope, particularly an arthroscope, having an inclined angle of view that can be manufactured and assembled efficiently. It would be further desirous for such arthroscope to direct illuminating light in the field of view without requiring extensive modification to the endoscopic tube member or the incorporation of high precision fitting members and adapters. It would also be advantageous for the arthroscope to incorporate features to positively mount the objective lens elements within the distal end of the scope without requiring additional lens mounting components.
SUMMARY OF THE INVENTION
Generally stated, the present invention is directed to a disposable rigid arthroscope having an inclined angle of view. The arthroscope comprises a frame member, an outer tube member extending distally from the frame member, an inner lens tube member eccentrically disposed within the outer tube member, optical means disposed within the inner lens tube member and having means for altering the field of view with respect to the optical axis and an illumination system including a plurality of optical fibers. The optical fibers of the illumination system are assembled and oriented to emit light in the general direction of the inclined field of view so as to sufficiently illuminate the surgical field. The materials of the arthroscope are advantageously selected to minimize the overall cost of the scope while providing for high level optical performance.
Further features of the invention, its nature and various advantages will be more apparent from the accompanying drawings and the following detailed description of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
Preferred embodiments of the invention are described hereinbelow with reference to the drawings wherein:
FIG. 1 is perspective view of the disposable arthroscope constructed according to the principles of the present invention;
FIG. 2 is an enlarged cross-sectional view taken along the lines 2--2 of FIG. 1 illustrating the inner lens tube of the arthroscope mounted within the outer tube;
FIG. 3A is a cross-sectional view of the distal end of the inner lens tube of the arthroscope;
FIG. 3B is a transverse cross-sectional view of the inner lens tube of the arthroscope;
FIG. 4A is a distal end view of the distal cover lens of the arthroscope;
FIG. 4B is a side plan view of the distal cover lens of the arthroscope;
FIG. 5A is a distal end view of the prism for altering the angle of view of the arthroscope;
FIG. 5B is a side plan view of the prism;
FIG. 6A is a side plan view of the distal end of the inner lens tube with an optical fiber orientating shim member positioned thereabout;
FIG. 6B is a distal end view of the inner lens tube and shim;
FIG. 7A is a side plan view of the distal end of the arthroscope with portions of the outer tube cut away illustrating the orientation of the illuminating optical fibers about the inner lens tube and the shim;
FIG. 7B is a distal end view of the arthroscope further depicting the orientation of the optical fibers;
FIG. 8A is a side plan view of an alternative optical fiber orientating shim and the distal lens of the inner tube depicting the shim prior to positioning about the lens tube;
FIG. 8B is a side plan view of the alternative shim positioned about the entire periphery of the inner lens tube;
FIG. 8C is an distal end view of the inner lens tube and alternative shim;
FIG. 9 is a side plan view in partial cross-section of the housing portion of the arthroscope illustrating the light guide connector with an illuminating coupler positioned therein;
FIG. 10 is a plan view with parts separated of the light guide connector and illuminating coupler illustrating the support member and the light transmissive element of the illuminating coupler;
FIG. 11A is a side plan view in partial cross-section of the coupler support member of the illuminating coupler of FIG. 10;
FIG. 11B is an axial view of the coupler support member of FIG. 11A;
FIG. 12 is a side plan view of the light transmissive element of the illuminating coupler of FIG. 10;
FIG. 13 is a cross sectional view of the illuminating coupler of FIG. 10 illustrating the light transmissive element mounted within the support member;
FIG. 14 is an optical schematic view of the objective lens assembly of the arthroscope of FIG. 1 illustrating ray path and image orientation;
FIG. 15 is an optical schematic view of the relay lens assembly of the arthroscope of FIG. 1 illustrating ray path and image orientation; and
FIG. 16 is an optical schematic view of the eye lens assembly of the arthroscope of FIG. 1.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to the drawings, in which like reference numerals identify similar or identical elements throughout the several views, FIG. 1 illustrates, in perspective view, an arthroscope 100 having an inclined angle of view constructed according to the principles of the present invention. Arthroscope 100 includes housing portion 200 and endoscopic portion 300 extending distally from the housing portion 200. Housing portion 200 supports eye piece assembly 220 which contains the eye lens assembly for viewing the image of the object formed by the optical system of the arthroscope, and light guide connector 240. Light guide connector 240 connects a light guide (not shown) which provides illuminating light to the illumination system of arthroscope 100. The components and function of light guide connector 240 will be discussed in greater detail below.
Referring now to FIG. 2, in conjunction with FIG. 1, endoscopic portion 300 of arthroscope 100 will be discussed in detail. Endoscopic portion 300 includes outer tube 310 and inner lens tube 320 disposed eccentrically within the outer tube 310. Outer tube 310 is preferably fabricated from a rigid material such as stainless steel or the like. Inner lens tube 320 is also preferably fabricated from stainless steel and houses the optical components of the objective and relay lens systems of the optical system. Inner lens tube 320 extends along the entire length of outer tube 310 and terminates within housing portion 200 at a position adjacent the eye lens assembly as shown in FIG. 9.
Referring again to FIGS. 1 and 2, distal end surface 312 of outer tube 310 is oblique or inclined, i.e., angularly offset relative to a plane extending generally transversely to the axis of endoscopic portion 300. In the preferred 30° arthroscope, the distal end surface 312 defines an angle of about 30° relative to the transverse plane. Similarly, distal end surface 322 of inner lens tube 320 is inclined at an angle "θ" (FIG. 3A) which measures about 30°. Although a 30° angle is preferred, the present invention is not so limited and could be within a range from 0°<θ<135°.
Referring now to FIGS. 2 and 3A-3B, distal end surface 322 of inner lens tube 320 includes a curved lip portion 324 at an upper portion of the lens tube. Lip portion 324 functions in mounting the distal optical components within inner lens tube 320 and also in positioning the optical fibers of the illumination system as will be discussed in greater detail below.
Lip portion 324 is preferably formed by initially curling the distal end surface of a cylindrical tube inwardly and thereafter cutting the distal end at the prescribed angle, i.e., 30°, to provide the oblique distal end surface 322 with the lip portion 324 on a portion of the extreme distal tip portion of the tube. Preferably, the outer surface 325 of lip portion 324 defines an angle "α" (FIG. 3A) of about 60° with respect to the longitudinal axis of inner lens tube 320 to concentrate illuminating light within the offset field of view.
Referring now to FIGS. 2, 4A-4B and 5A-5B, the novel method for positively mounting the distal lens components of the optical system 400 within inner lens tube 320 will be discussed in detail. FIGS. 4A-4B illustrate the distal most cover lens element 402 of the optical system. Cover lens 402 encapsulates the optical components within lens tube 320 as shown in FIG. 2 and has a distal face 404 which, when mounted within inner lens tube 320, is angled at 30° relative to optical axis 400a of the optical system 400. Cover lens 402 also has a lower edge 406 which defines a generally arcuate cross-section and conforms to the shape of inner lens tube opposite lip portion 324 when the top of cover lens 402 is disposed against lip portion 324. The proximal face 408 of cover lens 402 includes two projecting portions 408a, 408b, which mate to prism 410.
Prism 410 redirects the field of view relative to the optical axis "400a" (FIG. 2) of optical system 400. Prism 410 includes lower and upper arcuate surfaces 412, 414 (FIG. 5A) which generally conform to the shape of inner lens tube 320 and a recessed or notched portion 411 at its proximal end to accommodate glue or adhesives which are used in mounting the prism within lens tube 320 and to an adjacent optical component. The optical characteristics of prism 410 will be discussed in greater detail below.
During assembly, projections 408a, 408b are positioned within recess 416 of prism 410 in the manner depicted in FIG. 2. Thereafter, projections 408a, 408b are adhered to prism 410 by adhesives, cements or the like to form a one-piece assembled unit. Cover lens 402 and adhered prism 410 are then inserted into the proximal end of lens tube 320 and advanced into the lens tube until distal face 404 of cover lens 402 contacts lip portion 324 of the lens tube 320. Distal cover lens 402 and prism 410 are positively constrained within inner lens tube 320 due to the engagement of edge 406 of cover lens 402 with the lower surface of the lens tube 320 and the engagement of upper edge 409 of cover lens 402 with curved lip portion 324 of the lens tube 320. Furthermore, cover lens 402 and prism 410 are prevented from tipping proximally and/or distally due to the engagement of lower and upper surfaces 412, 414 (FIG. 5A) of prism 410 with the interior of inner lens tube 320. Similarly, cover lens 402 and prism 410 are prevented from rotating due to the constraining action of curved lip portion 324. The remaining optical components of the optical system, including the objective and relay lens assemblies, are mounted within inner tube 320 by insertion of each component in the proximal end of the inner tube and mounting these components in a conventional manner.
Referring now to FIGS. 6A-6B and 7A-7B, the novel mechanism for orientating the optical fibers of the illumination system 500 to direct illuminating light in the perspective visual field as provided by prism 410 will be discussed in detail. An optical fiber orientating shim 330 is positioned about the lower peripheral surface of inner lens tube 320. Shim 330 serves as a guide to position the end portions of each illumination fiber 510 at a desired orientation so as to direct light emitted by the optical fibers into the field of view of the arthroscope. Shim 330 includes two side portions 332 which are sloped downwardly towards the lower portion of inner lens tube 320. In the preferred 30° arthroscope, each side portion 332 defines an angle "β" (FIG. 6A) of about 30° relative to the optical axis such that the illumination fiber end portions 510, disposed on either side of lens tube 320, are oriented at a 30° angle relative to optical axis 400a (FIG. 2), and perpendicular to distal end surface 322 of the inner lens tube 320. The remaining illumination fiber end portions 510 disposed adjacent the top of the inner lens tube 320 are oriented to direct light in the field of view by the angled peripheral surface 325 of curved lip portion 324 at distal end face 322. Thus, sloped side portions 332 of shim 330 in combination with the peripheral surface 325 of curved lip portion 324 effectively position and retain the end portions of illumination fibers 510 at the desired 30° orientation in the assembled condition of arthroscope 100. As best shown in FIG. 7B, illumination fibers 510 are disposed in a crescent-shaped array about inner lens tube 320 within the space defined by outer lens tube 310, inner lens tube 320 and shim 330 when assembled within arthroscope 100. Preferably, the fibers 510 are placed onto the inner lens tube 320 about shim 330 and within the outer tube 310 prior to assembly of the optical assembly within the inner tube.
Shim 330 is preferably formed by replica molding techniques. In the preferred method, a Teflon mold (not shown) made in the shape of the shim 330 is provided. The mold has sides angled at the desired curvature of side portions 332 of shim 330. To form shim 330 directly onto inner lens tube 320, a drop of ultraviolet (UV) curing cement is placed at the bottom of the mold. Inner lens tube 320 is then oriented in the mold (related positioning fixtures may be used), causing the uncured cement to surround inner lens tube 320 in the shape of the mold. A UV light is then activated to cure the cement. Inner lens tube 320 can then be removed from the mold with shim 330 formed thereon. Replica molding techniques are desirable for forming shim 330 on inner lens tube 320 in that such techniques are capable of forming precision shim components relatively inexpensively and in large quantities. Further, such molding technique positively fixes shim 330 to inner lens tube 320, thus, eliminating an assembly step which would otherwise be necessary during manufacture of arthroscope 100.
Shim 330 also assists in positively positioning inner lens tube 320 within outer tube 310. As shown in FIGS. 2 and 7A-7B, the proximal end portion 331 of shim 330 preferably extends to the maximum inner diameter of outer tube 310 and fills the space surrounding the lower portion of inner lens tube 320. Thus, inner lens tube 320 is prevented from side to side movement within outer tube 310 and up and down movement within the outer tube by the engagement of shim 330 with the inner walls of the outer tube.
In the preferred method for positioning illumination fibers 510 of illumination system 500 about shim and within arthroscope 100, the illumination fibers 510 are placed into outer tube 310. Inner lens tube 320, already cut at an angle and having curved lip portion 324 formed thereon, is inserted into outer tube 310 with the fibers 510 disposed within the space defined between the two tubes. At this point in the procedure, the fibers extend out of both ends of outer tube 310. A collar may be placed around illumination fibers 510 at the proximal end of outer tube 310 and the collar positioned within a jig. The jig positions the collar, fibers 510 and tube 310 in the orientation they will assume in the final assembled condition of arthroscope 100. A heat curing cement is placed around the fibers at the collar and the entire device is heated to bond the fibers within and to the collar. A heat curing cement is acceptable where glass fibers are used. If desired, particularly if plastic fibers are used, a UV curing cement may be utilized.
At the distal end of outer tube 310, illumination fibers 510 are divided into a middle (top) group and two side groups. Each group is bent downwardly. The top group of fibers 510 is guided at the appropriate angle by curved lip portion 324 of inner lens tube 320. The side groups of fibers are guided by shim 330. All groups are restrained in their respective positions by a fixture. Cement (which may again be heat cured) is applied to the three groups of fibers 510 and cured.
In the preferred method, cementing of the fibers at the distal end is a two-step process. A low viscosity cement is first applied and is wicked along fibers 510 inside inner tube 320. Suitable cements for this purpose are manufactured by Epoxy Technology of Watertown, Mass., under the tradenames EPO TEK 350ND and EPO TEK 350ND-T. The first cement is baked to cure and a second, high viscosity cement is applied to fill any voids around fibers 510 at the distal end surface 322 and to act as a sealant to prevent moisture and/or bodily fluids from contacting the lenses of the optical system. A suitable high viscosity cement is Vitralit 1710 manufactured by Elosol Ltd. of Zurich, Switzerland. The second cement is baked to cure. The excess ends of fibers 510 are cut, and the fiber surfaces at the proximal and distal ends are ground and polished. If necessary, it is contemplated a sealant could be applied to the distal end of the scope. The aforementioned Vitralit 1710 is appropriate for use as a sealant for this purpose. Once inner tube 320 is fully assembled within outer tube 310, fibers 310 are compressed and retained at their appropriate angular orientation by side edges 332 of shim 330 and surface 325 of inner lens tube 320.
Referring now to FIGS. 8A-8C, an alternative embodiment of the fiber orienting shim is illustrated. In this embodiment, shim 340 extends about the entire periphery of the distal end of inner lens tube 320. Shim 340 includes side portions 342 which are sloped downwardly at an angle relative to the axis of inner lens tube 320 in a similar manner to that described in connection with the previous shim. Upper distal surface 344 of shim 340 is also sloped downwardly. Side portions 342 and sloped upper surface 344 position optical fibers 510 in a manner substantially similar to that described in connection with the shim of FIGS. 6A and 6B. In particular, the top group of fibers 510 adjacent the upper portion of outer tube 310 are guided by the angled surface of distal surface 344 of shim 340 and the side groups of fibers are positioned by side portions 342. Thus, in accordance with this embodiment of shim 340, it is not necessary to form the curved lip portion 324 of inner lens tube 320 to guide the top group of fibers. Shim 340 may be formed by conventional molding techniques or, in the alternative, by a replica molding technique. Optical fibers 510 are disposed in a similar crescent shaped array as the embodiment illustrated in FIG. 7B.
Optical fibers 510 of illumination system 500 are each preferably glass fibers having a diameter which enables the fibers to be bent and oriented about shim 330, 340. In the preferred embodiment, fibers 510 may have a diameter ranging from about 50 microns to about 90 microns.
Referring now to FIG. 9, in conjunction with FIG. 1, housing portion 200 of arthroscope 100 includes two housing half sections 210. Half sections 210 are preferably formed of a suitable plastic material such as ABS (acrylonitrile butadiene styrene), polycarbonate, polypropylene, polyethylene or the like, or, in the alternative, of a metal such as stainless steel, and are attached along a seam by suitable attachment techniques, including adhesives and/or ultrasonic welding. Eye piece assembly 220 is secured within the proximal end of housing 200 by conventional means.
Referring now to FIGS. 1, 9, and 10, the novel mechanism for coupling light into the illumination system of arthroscope 100 will be discussed in detail. By way of background, conventional light guides connected to a light source typically have a working diameter or illuminating aperture of about 5 mm to correspond to conventional endoscopes which also typically have a 5 mm diameter entrance or illuminating aperture as defined by the entrance end of the fiber optic bundle of the illumination system. However, since arthroscopes, including arthroscope 100 of the present invention, are typically smaller in diameter than conventional endoscopes, the entrance illuminating apertures of such arthroscopes are also smaller. In particular, the entrance illuminating aperture of arthroscope 100 of the present invention, as defined by the proximal entrance end 515 of fiber optic bundle 500 (See FIG. 9) ranges from about 2-2.5 mm. In order to minimize loss of light from a 5 mm light guide, an illuminating coupler 242 is provided.
Referring now to FIGS. 9-13, illuminating coupler 242 is disposed within light guide connector 240 and includes support member 244 and a light transmissive optical element 246 disposed within the support member. Support member 244 is generally cylindrically shaped and includes a generally frustoconical inner chamber 248 as defined by the tapering inner walls 250 of the support member 244. The lower portion of support member 244 includes three projections 252 which extend into chamber 248. Light transmissive element 246 is generally frustoconically shaped and includes a circumferential ledge 254 at its larger diameter portion and a peripheral recessed portion or well 247 at its lower end portion. In the assembled condition of frustoconical optical element 246 within support member 244 as shown in FIGS. 9 and 13, the frustoconical element 246 is spaced from the support member 244 by an air gap. Such spacing is provided by the engagement of projections 252 with the lower end portion of frustoconical element 246. Also, in the assembled condition, circumferential ledge 254 of frustoconical element 246 rests on the upper surface 256 of support 244 to assist in mounting the frustoconical element 246 within the support 244. The lower surface or exit side 260 of frustoconical element 246 and optical fibers 510 at proximal entrance end 515 are disposed in face-to-face relation as best shown in FIG. 9. Preferably, an epoxy glue is applied between lower surface 260 and the proximal entrance end 515 to maximize coupling efficiency between the fibers 510 and the lower surface 260. Recessed portion 247 of frustoconical element 246 accommodates any excess epoxy glue which may overflow into this area so as to ensure that a bead does not form at the lower end portion of the frustoconical element 246. The formation of an epoxy bead would degrade the light transmissive characteristics of frustoconical element 246.
Illuminating coupler 242 minimizes the loss of light when a light guide having a relatively large working diameter, typically 5 mm, is coupled to light guide connector 240 of arthroscope 100 which possesses an illumination aperture of about 2.5 mm. In particular, light entry side 258 of frustoconical element 246 has a working diameter "a" (FIG. 12) of about 5 mm. The smaller diameter exit side 260 of element 246 which is adjacent the proximal end 515 of the illumination system has a diameter "b" of about 2.5 mm. Accordingly, light expelled from a 5 mm light guide onto entry side 258 of light transmissive element 246 is directed through the frustoconical element 246 and released from the 2.5 mm diameter exit side 260 of the element onto the proximal end of the optical bundle. Due to the differences in the indices of refraction of frustoconical element 246 (nd of about 1.5) and air (nd=1.0), the air gap defined between frustoconical element 246 and support 244 minimizes leakage of light from element 246 thereby ensuring maximum transfer of illuminating light through element 246 and into illumination system 500.
Light transmissive element 246 is preferably molded of acrylic or polycarbonate. The inner walls 250 of support member 244 may be ground from a 0.25 microfinish to about a 0.45 microfinish, which produces a highly reflective surface to direct any stray light back into light transmissive element 246. The walls of light transmissive element 246 may also be cladded with a reflective aluminum coating, which would obviate the need to suspend the cone in air.
Referring now to FIGS. 14-16, the optical system of the present invention is illustrated in detail. The optical system includes an objective lens assembly (FIG. 14) for forming an image of an object, a relay lens assembly 440 (FIG. 15) for transferring the image through endoscopic portion 300 and eye lens assembly 460 (FIG. 16) for viewing the transferred image.
As shown in FIG. 14, objective lens assembly includes distal cover lens 402, prism 410, first or distal doublet 420, triplet 422 and second or proximal doublet 424. An aperture stop may be provided between prism 410 and first doublet 420 to limit the diameter of the light rays transferred through the system. Cover lens 402 is a plano concave lens. Prism 410 is preferably molded of a suitable polymeric material including styrene, polycarbonate and acrylic or, in the alternative, may be formed from an optical glass. The prism may also be formed of molded glass.
Referring to FIGS. 5A-5B and 14, prism 410 is a 30° deflection prism which changes the direction of view of arthroscope 100 from forward viewing to viewing at an oblique angle, i.e., at a 30° angle relative to the optical axis of the optical assembly. In a preferred embodiment, prism 410 is a hybrid prism, i.e., one which principally reflects light, but, also refracts the light so as to change the angle of view. In the alternative and depending on the particular applications, prism 410 may be a full reflection prism or a full refraction prism. A full refraction prism is preferably used when it is desirable to change the angle of view less than 30° relative to the optical axis. Other suitable methods for altering the angle of view, such as mirrors and fiber optics, may also be utilized.
FIG. 14 illustrates ray path and image orientation through the objective lens assembly. The geometrical characteristics of the objective assembly are defined by an object plane 425a, surfaces 425b-c of cover lens 402, surfaces 425d-g of prism 410, surfaces 425h-425j of first doublet 420, surfaces 425k-425n of triplet 422, surfaces 425o-425q of doublet 424 and exit image plane 425r, respectively. The geometrical and optical parameters of the objective assembly are recorded in Table 1 below. In the Table, surfaces A, B-C, D-G, H-J, K-N, O-Q and R correspond to object plane 425a, surfaces 425b-c of cover lens 402, surfaces 425d-g of prism 410, surfaces 425h-425j of first doublet 420, surfaces 425k-425n of triplet 422, surfaces 425o-425q of second doublet 424 and exit image plane 425r, respectively.
TABLE 1______________________________________ THICK- ABBESURFACE RADIUS NESS MEDIUM INDEX NO.______________________________________A Object (Object AIR 1.000 Plane Distance)B Plano 0.7 Styrene 1.590 30.9C 0.800 0.7 AIR 1.000D -1.100 1.0 Styrene 1.590 30.9E Plano 1.4 Styrene 1.590 30.9F Plano 1.4 Styrene 1.590 30.9G Plano 0.2 AIR 1.000H 19.763 1.0 Styrene 1.590 30.9I 1.500 1.9 Acrylic 1.492 57.4J -2.062 0.3 Air 1.000K 4.132 2.5 Acrylic 1.492 57.4L -1.500 1.0 Styrene 1.590 30.9M 4.000 1.4 Acrylic 1.492 57.4N 2.304 0.6 AIR 1.000O 2.391 2.0 Acrylic 1.492 57.4P -4.300 1.5 Styrene 1.590 30.9Q -11.500 4.8 AIR 1.000R Exit Image Plane______________________________________ *dimensions are in millimeters
Surfaces 425e, 425f of prism 410 are reflecting surfaces. Surface 425e defines an angle ranging from about 18° to about 26°, preferably about 22.5°, relative to the optical axis while surface 425f defines an angle which ranges from about 4.5° to about 10.5°, preferably about 7.5°, relative to the optical axis.
The objective lens arrangement produces an inverted image of the object at exit image plane 425r. As indicated in Table 1, the distance from the proximal lens surface 425q of second doublet 424 to exit image plane 425r is about 4.8 mm. The inverted image formed by the objective lens arrangement is subsequently transmitted by relay lens assembly 440.
Referring to FIG. 15, a relay lens module 442 of relay lens assembly 440 is illustrated in detail. Relay lens assembly 440 may include a plurality of relay lens modules, arranged in end to end fashion along the optical axis. Each module 442 is identical with regard to the optical components contained therein, and is capable of transferring an image from an image plane at the entrance side of the module to a successive image plane formed on the exit side. Lens module 442 includes two identical optical assemblies 444 arranged in symmetrical end to end relationship relative to a median plane disposed between the two assemblies. Assemblies 444 are separated by an air gap. Each assembly 444 includes a glass plano cylinder 446 having an adjacent end face and an outer end face relative to the other component in the module. Glass plano cylinder 446 ensures the transfer of a bright image between the modules. Each assembly further includes a single lens 448 bonded to the outer end face of plano cylinder 446 and a single lens 450 bonded to the adjacent end face of the cylinder. Single lens 448, 450 are each preferably a plano-convex lens. The convex surface of lens 448, 450 may be coated with a broad band anti-reflection coating to reduce reflection losses at the air-lens interface. Single lenses 448, 450 are each preferably fabricated from a polymeric material such as an acrylic, polystyrene, polycarbonate, or copolymer styrene-acrylonitrile (SAN). In a preferred embodiment, single lenses 448, 450 are each fabricated from acrylic.
FIG. 15 illustrates ray path and image orientation through lens module 442. The geometrical characteristics of module 442 are defined by an entrance image plane 445a, a front surface 445b, a first bonded surface 445c, a second bonded surface 445d, a first inner surface 445e, a second inner surface 445f, a third bonded surface 445g, a fourth bonded surface 445h, a rear surface 445i and an exit image plane 445j. The geometrical and optical parameters of the module are recorded in Table 2. In Table 2, surfaces A, B-I and J correspond to image plane 445a, surfaces 445b-445i and exit image plane 445j, respectively. Table 2 is as follows.
TABLE 2______________________________________ THICK- ABBESURFACE RADIUS NESS MEDIUM INDEX NO.______________________________________A Entrancet 2.5 AIR 1.000 Image PlaneB 7.350 1.4 Acrylic 1.492 57.4C Plano 24.0 SF2 1.648 33.9D Plano 1.5 Acrylic 1.492 57.4E -9.700 0.2 AIR 1.000F 9.700 1.5 Acrylic 1.492 57.4G Plano 24.0 SF2 1.648 33.9H Plano 1.4 Acrylic 1.492 57.4I -7.350 2.5 AIR 1.000J Exit Image Plane______________________________________ *dimensions are in millimeters
As indicated in Table 2, the distance between entrance image plane 425a and the first lens surface 445b of lens 448 is approximately 2.5 mm. Similarly, the distance between proximal lens surface 445i of lens 448 and exit image plane 445j is also 2.5 mm.
In a preferred embodiment, the relay lens assembly comprises three lens modules aligned in end to end fashion along a common axis.
It is also envisioned that other relay lens assemblies may be incorporated in the optical system of arthroscope 100. Examples of relay lens assemblies which may be adapted for use with arthroscope 100 are disclosed in U.S. Pat. Nos. 4,964,710 to Leiner and 5,188,092 to White and commonly assigned copending U.S. patent application Ser. Nos.: 08/132,007 filed Oct. 5, 1993, 08/132,009 filed Oct. 5, 1993, and 08/120,887 filed Sep. 13, 1993, the contents of each patent and pending application being incorporated herein by reference.
Referring now to FIG. 16, the eye lens assembly of optical system is illustrated in detail. Eye lens assembly 460 includes a doublet lens 462 having two polymeric lens elements 464, 466 which are bonded to each other along adjacent end surfaces. Preferably lens element 464 is a double convex lens and is fabricated from an acrylic while lens element 466 is a meniscus lens and is fabricated from a styrene. The geometrical characteristics of eye lens assembly 460 are defined by entrance image plane 465a, surfaces 465b-d and exit image plane 465. Table 3 below identifies the optical parameters of the eye lens assemblies.
TABLE 3______________________________________ THICK- ABBESURFACE RADIUS NESS MEDIUM INDEX NO.______________________________________A Image 9.1 AIR 1.000 PlaneB 13.500 1.8 Acrylic 1.492 57.5C -2.000 1.7 Styrene 1.590 30.9D -5.270 11.0 AIR 1.000E Exit Pupil______________________________________ *dimensions are in millimeters
As indicated in Table 3, the distance between the image plane 465a and the first lens surface 465b of eyelens 462 is approximately 9.1 mm.
It is also contemplated that the view finder or eyepiece assembly 220 having eye lens assembly 460 therein may be connected to a video camera adapter to enable the image to be displaced on a monitor for viewing by the surgical team. It is also possible that the eyepiece assembly 220 may be eliminated so that the optical system is connected directly to the video camera optics.
The optical system of the arthroscope of the present invention provides a clear bright image to the viewer and effectively compensates for predetermined aberrations in the system such as axial chromatic aberration, lateral chromatic aberration and astigmatism. The optical system can be manufactured sufficiently inexpensively to supply the entire arthroscope as a disposable unit. The principle optical components including the prism may be molded of plastic thus further minimizing the cost of the arthroscope. The glass plano cylinder of the relay lens system can also be manufactured cost effectively.
To the extent not already indicated, it also will be understood by those of ordinary skill in the art that any one of various specific embodiments herein described and illustrated may be further modified to incorporate features shown in other of the specific embodiments.
The invention in its broader aspects therefor is not limited to the specific embodiments herein shown and described but departures may be made therefrom within the scope of the accompanying claims without department from the principles of the invention and without sacrificing its chief advantages. | An arthroscope includes an frame member, an illumination system and a light guide connection port associated with the frame member for connecting to a light guide to transfer illumination light to the illumination system. The light guide connection port includes a support member having a tapered inner wall portion for supporting a transmissive element having a tapered portion. The support member includes a plurality of inner mounting projections extending from the tapered inner wall portion and being radially arranged and positioned to contact the outer surface of the light transmissive element to maintain the light transmissive element in spaced relation relative to the tapered inner wall portion. | 0 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to textile machines utilizing a spline coupling between a flyer and spindle arrangement, and more particularly pertains to a spline coupling which is also used as a sealing means between a flyer and spindle connection.
2. Description of the Prior Art
Those concerned with the development of spline couplings, which are positionable within a gear housing attached to a flyer and engageable with a spindle gear associated with a spindle thereby to create a driving connection therebetween, have long recognized the need for reducing the amount of lint which effectively becomes entrapped within the gear housing about the spindle gear and spline coupling gear teeth. Further, there has been a long recognized need for some means of preventing spindle gear oil from coming in contact with the base of a bobbin positioned upon the spindle whereby the oil is eventually transferred to the sliver during a spinning operation. Similarly, in that many mills wet the sliver ends when starting a roving frame, a critical problem has long confronted developers as to how to prevent drops of water from running down a bobbin and, in turn, into a spindle gear. The problems of lint accumulation in a gear housing, oil contamination of a spinning sliver and water damage to a spindle gear are substantially eliminated by the present invention.
SUMMARY OF THE INVENTION
The general purpose of the present invention is to provide a spline coupling and spindle washer combination which overcomes the above-described disadvantages. To attain this purpose, the present invention provides for the use of a spline coupling and spindle washer combination which is positionable within a gear housing attached to a flyer and which is engageable with a spindle gear associated with a spindle. In this connection, the spline coupling of the present invention has concentrically aligned with and integrally attached thereto a spindle washer which effectively serves as a seal between the spline coupling and that portion of the spindle emerging therefrom for engagement with a bobbin. Through the integral attachment of the spindle washer to the spline coupling, no inertial effect is experienced as the result of centrifugal force experienced during spindle and flyer rotation, as well as bobbin stroke, which normally would cause a spindle washer to ride upward on the spindle resulting in lint, oil and water contamination.
Accordingly, it is an object of the present invention to provide for a new and improved connection means between a spindle and flyer.
Another object of the present invention is the provision of an effective seal between a flyer and spindle arrangement.
A further object of the present invention is the provision of a new and improved spline coupling having a spindle washer integrally attached thereto.
Still another object of the present invention is to provide for the alleviation of lint collection within a gear housing wherein a spline coupling effects a connection between a flyer and spindle arrangement.
A still further object of the present invention is the prevention of oil contamination of a silver associated with a bobbin as the result of oil leakage from a spindle gear.
Yet another object of the present invention is the elimination of spindle gear damage associated with water leakage from a bobbin.
These together with other objects and advantages which will become subsequently apparent reside in the details of construction and operation as more fully hereinafter described and claimed, reference being had to the accompanying drawings forming a part hereof, wherein like numerals refer to like parts throughout.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a bobbin and spindle arrangement having a gear housing positioned therebetween to which is attached a flyer.
FIG. 2 is a partial cross-sectional view of the apparatus shown in FIG. 1 taken on the line 2--2.
FIG. 3 is a cross-sectional plan view of the apparatus shown in FIG. 2 taken along the line 3--3.
FIG. 4 is a perspective view of the spline coupling and spindle washer combination of the present invention.
FIG. 5 is a bottom plan view of a modified embodiment of the present invention which utilizes a skip tooth spline coupling.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to the drawings and, in particular, to FIG. 1 wherein there is illustrated in perspective a spindle 10 which is drivingly connected to a flyer 12 through unshown connection means positioned within a gear housing 14. A bobbin 16 is shown positioned over that portion of spindle 10 which emerges from the gear housing 14 through opening 18. The gear housing 14 includes a pair of upwardly extending tubular portions 20, 22, into which are insertable flyer arms 24, 26, respectively.
Referring next to FIG. 2, it can be seen that the spindle 10 includes a narrow portion 28 which extends through the gear housing 14 and over which is positionable the bobbin 16. In this respect, the bobbin 16 is of a tubular construction having a hollow interior and a lower base portion 30 with resilient engaging means 32 positioned on the interior of the bobbin and proximate to the bobbin base. Typically, the resilient engagement means 32 comprises a rubber ring which is fixedly attached to the interior portion of the bobbin 16 and the center of the ring is of a lesser diameter than the narrow spindle portion 28, thereby to effect a frictional engagement between the narrow spindle portion and the bobbin.
Also illustrated in FIG. 2 is the positioning of the flyer arm 24 within tubular portion 20 of gear housing 14, as well as the positioning of flyer arm 26 within tubular portion 22. Additionally, a spindle gear 34 is shown, such gear being fixedly attached to the spindle narrow portion 28 and being in engagement with the spline coupling and spindle washer combination 36 of the present invention. In this respect, the combination 36 of the present invention includes a coupling portion 38, the teeth of which engage with the teeth of the spindle gear 34 in the area designated by the numeral 40, and a concavely upwardly-sloped spindle washer portion 42 integrally attached thereto. As can be observed with reference to FIG. 2, the spindle washer portion 42 is in close engagement with the spindle narrow portion 28 so as to protectively seal the spindle gear 34 and spline coupling portion 38 from the bobbin 16. In this regard, the spindle washer portion 42, as well as the coupling portion 38, are envisioned as being constructed of a resilient material, such as plastic or the like, to thereby facilitate the positioning and sealing effect of the combination 36 within the gear housing 14.
Referring now to FIG. 3 of the drawings, it can be seen that the spindle gear 34 includes a plurality of teeth 44 which are in turn engageable with the teeth 46 associated with the spline coupling portion 38. The spindle gear 34 is concentrically aligned and fixedly attached to the narrow spindle portion 28 which is illustrated as having a hollow interior 48. The gear housing 14 includes a plurality of inwardly extending projections 50, while the spline coupling portion 38 of the present invention has a plurality of cut-outs 56 which are designed for specific alignment and engagement with the projections 50.
A better understanding of the construction of the present invention can be obtained by reference to FIG. 4 of the drawings, which is a bottom perspective view of the spline coupling and spindle washer combination 36. In this respect, the spline coupling portion 38 is illustrated with its attendant cut-outs 56, while the spindle washer portion 42 is shown protectively positioned above the spline coupling gear teeth 46. Additionally, a downwardly extending lip portion 58 is illustrated whereby the spline coupling gear teeth 46 are integrally associated with a thicker section of the spline coupling portion 38 than are the cut-outs 56.
While FIG. 4 of the drawings illustrates an embodiment of the present invention which might be referred to as a 40-tooth spline coupling and spindle washer combination, FIG. 5 illustrates a modified embodiment in which the number of spline coupling gear teeth is varied. In this illustrated arrangement, a spindle washer portion 42 is shown from a bottom plan view as being integrally attached to a skip tooth spline coupling 60. The only variation between this embodiment of the present invention from the embodiment illustrated in FIG. 4 is the number of spline coupling gear teeth 46 associated therewith. This particular embodiment is designed to shear more readily than the 40-tooth spline coupling and as such, is illustrative of the variations possible with the spline coupling and spindle washer combination of the present invention.
In use and with reference to FIG. 2 of the drawings, it can be seen that the spline coupling and spindle washer combination 36 of the present invention serves the purpose of providing a driving engagement between the flyer 12 and spindle 10, and further serves to provide a seal between the spindle gear 34 and the bobbin 16. When positioned as illustrated within the gear housing 14, water which runs down the bobbin 16 will be prevented from coming into contact with the spindle gear 34, since the spindle washer portion 42 provides an upwardly sloping surface over which the water will be directed away from the spindle gear. Similarly, lint dropping downwardly from the bobbin 16 will also be prevented from coming into engagement with the spindle gear 34 by the spindle washer portion 42 which is integral with the spline coupling portion 38. By the same token, oil and grease which is used to lubricate the spindle gear 34 will be prevented from moving upwardly towards the bobbin 16 so as to contaminate thread contained thereon due to the positioning of the spindle washer portion 42, as illustrated.
Optimum dimensional relationships for the parts of the invention are deemed readily apparent and obvious to one skilled in the art, and all equivalent relationships to those illustrated in the drawings and described in the specification are intended to be encompassed by the invention. As such, it should be understood that the foregoing disclosure relates to only preferred embodiments of the invention and that numerous modifications or alterations may be made therein without departing from the spirit and scope of the invention as set forth in the appended claims. | A spline coupling positionable within a gear housing for coupling a flyer to the spindle gear of a spindle has an integrally attached spindle washer for effecting a seal about the spline coupling and spindle gears. The spindle washer is attached to an uppermost portion of the spline coupling and serves to prevent oil, water and lint from reaching both the spindle gear and the base of a bobbin positionable over the spindle. | 3 |
BACKGROUND OF THE INVENTION
The present invention relates generally to the bonding of an interposer with a lead frame in semiconductor packaging applications. More particularly, an improved method and apparatus for maintaining contact between the interposer and lead frame during single point bonding is disclosed.
In semiconductor packaging, lead frames are commonly used to couple a die to external components. In some applications (particularly small high lead count packages), it may be desirable or necessary to use an interposer in conjunction with the lead frame. The interposer is similar to a mini printed circuit board having traces. The lead frame is ultrasonically bonded directly onto underlying traces on an interposer, and the bonding pads on the dies are electrically coupled to the other end of the trace using bonding wires. One end of each bonding wire is typically ultrasonically bonded to a die pads on the die and the opposite end is typically bonded to an associated lead.
During an ultrasonic bonding process, the quality of the bond formed between the bonding surfaces is a major concern. This concern is especially acute during lead frame-interposer integration where high power bonding is necessary. High power is required to transfer the ultrasonic energy through the thick lead to the underlying interposer trace. In high power bonding, it is difficult to maintain contact between the bonding surfaces, the lead and the interposer trace. Any deviation in the quality of the contact between the bonding surfaces directly affects the bond quality.
Referring to FIG. 1, a conventional approach to providing a lead frame clamp during lead frame-interposer integration, generally designated by reference numeral 100, will be described. The lead frame clamp 100, which is in the form of a window clamp, includes a contact section 16 having a window hole 18, two support sections 14, and a plurality of fasteners. Each fastener is in the form of a fastener hole 12 and a screw or rivet 13. During the bonding process, screws or rivets 13 are inserted into the fastener holes 12, and the fasteners are attached to and support the support sections 14 in a fixed position. The support sections 14 are attached to and support the contact section 16 in a fixed position so that the contact section 16 touches and applies pressure to an area of the lead frame that includes the lead tips. A portion of the lead tip ends are left exposed by the window hole 18 and are not covered by the contact section 16. While pressure is being applied by the contact section 16 to the lead frame and underlying interposer, the exposed lead tips are bonded to the traces on the interposer.
Unfortunately, these conventional lead frame clamps possess certain drawbacks. First, the amount of movement of a lead is higher for a lead with an axis that lies in a direction perpendicular to the bonding tool's movement than for a parallel lead. This difference in movement results in higher attenuation of the ultrasonic energy for the perpendicular lead than for the parallel lead. This difference in attenuation dictates that the optimal bonding power for the parallel leads is greater than the optimal bonding power for the perpendicular leads. However, when the bonding power is high, and ultrasonic energy is applied for a longer period than is necessary to facilitate bonding, the interposer traces are more likely to break or the bond itself may be destroyed during bonding. Second, since the perpendicular leads easily move during bonding, the resulting bond quality is adversely affected. Third, if the bonding power is high enough, the vibration resonance on previously bonded points may be high enough to destroy these bonds. These three problems illustrate the need to improve the stability of the lead frame and the interposer during the bonding process. Thus, an improved clamping mechanism would be desirable.
SUMMARY OF THE INVENTION
To achieve the foregoing and other objects and according to the purpose of the present invention, a lead frame clamping arrangement is disclosed that clamps the leads to be ultrasonically bonded at two spaced apart locations. In one preferred embodiment, the clamping arrangement includes a lead arm clamp and a lead tip clamp that are spaced such that an exposed bonding area of a selected lead is positioned between the first and second segments of the selected lead. During bonding of the selected lead to its associated trace, a bonding tool tip may be positioned over the exposed bonding area to facilitate coupling the selected lead to its associated trace in the exposed bonding area. In one embodiment of the invention, the lead tip clamp includes a spring plate. In another preferred embodiment of the invention, the lead arm clamp is in the form of a window clamp which includes a window and the spring plate is positioned within the window hole while associated leads of the lead frame are being coupled to associated bonding pads on the interposer. In another aspect of the invention, a wire bonder that utilizes the described clamp is disclosed.
In a method aspect of the invention first and second portions of a lead frame lead are clamped. A bonding tool is then positioned over a third portion of the lead (the bonding area) that is positioned between the first and the second portions of the lead. The third portion of the lead is then ultrasonically welded to an associated interposer trace while the first and second portions of the lead are securely held in place by their associated clamps. In one preferred embodiment, the clamps are arranged to hold a plurality of leads such that additional traces on the substrate are then bonded to their associated leads without releasing the lead tip clamp and without releasing the lead arm clamp.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention, together with further objects and advantages thereof, may best be understood by reference to the following description taken in conjunction with the accompanying drawings in which:
FIG. 1 is a diagrammatic perspective view of a conventional lead frame clamp.
FIG. 2 is a diagrammatic exploded perspective view of a lead frame clamp made in accordance with one embodiment of the present invention.
FIG. 3 is a diagrammatic top view of the embodiment of FIG. 2 which further shows the lead frame and interposer configuration during the bonding process in accordance with the present invention.
FIG. 4 is a cross-sectional side view of the embodiment of FIG. 3.
DETAILED DESCRIPTION OF THE INVENTION
Lead frame clamps made in accordance with one embodiment of the present invention are shown in FIGS. 2, 3, and 4. FIG. 2 shows only a lead frame clamp, while FIGS. 3 and 4 depicts a lead frame clamp, as well as the lead frame and interposer, during an ultrasonic bonding process.
As best seen in FIG. 2, the embodiment shown is particularly well adapted for use in conjunction with lead frames having radially extending leads as is common in quad flat pack (QFP) and various other packaging configurations. In this embodiment, the lead frame clamp 200 has two clamping mechanisms: a lead arm clamp member 16 and a lead tip clamp member 21. Additionally, the lead frame clamp includes fasteners 13 which are provided to secure the lead frame clamp to a support member during bonding. Preferably, the lead arm clamp 16 is in the form of a window clamp that clamps all of the radially extending leads, leaving their free standing lead tips exposed. This portion of the lead frame clamp is very similar to conventional window clamps and includes a window 18. The lead tip clamp 21 takes the form of a spring clamp that is positioned within the window 18 such that clamps the free ends of each of the leads tips that are exposed within the window 18. The spring clamp 21 is sized such that a channel or gap is formed around the spring clamp and between the spring clamp and the window clamp. The gap is sized to allow a bonding tool to fit between the spring and window clamps. The gap's size depends on many factors, such as the type of bonding tool used and the type of bonding being performed. For example, a gap size that's in the range of about 20 to 30 mils has been found to work well.
In the embodiment shown, the spring clamp 21 includes a spring plate 24 which is attached to and suspended from a holder 22. The window clamp 18 has a pair of arms 14 that extend in opposite directions from the window 18. One of the arms 14 of the window clamp 16 is attached to and supports the spring clamp, as well as the window clamp. More specifically, during the bonding process, the arms are affixed to a support member by the fasteners 13. One of the arms is attached to and supports the holder. The holder is attached to and positions the spring plate within the window 18 of the window clamp. As a result, the spring clamp supports and clamps the underlying lead frame.
The fasteners 13 may take any suitable forms that are capable of affixing the lead frame clamp 200 to a support member. By way of example, the fasteners 13 may take the form of screws or rivets. Each screw or rivet is inserted into a fastener hole 12 within each arm 14 of the window clamp and into a hole within a support member. By way of another example, the fasteners may take the form of steel balls that are held down by a spring plate. The steel balls, in turn, hold the lead frame clamp in place.
In summary, the lead frame clamp 200 configuration described above has two distinct clamping mechanisms for affixing and holding an underlying object, such as a lead frame: the window clamp 16 and the spring clamp 21. These clamping mechanisms are engaged when the lead frame clamp 200 is fastened to a support member. An application which implements these clamping mechanisms will be fully described below with reference to FIGS. 3 and 4.
In the described embodiment, the spring clamp 21 is attached via the holder 22 to one of the arms 14 of the window clamp 16. However, it should be appreciated that in other embodiments, the spring clamp and the window clamp may be two separate pieces. By way of example, the spring clamp may be attached to the same support member, to which the arms of the window clamp are attached. Additionally, the spring clamp and window clamp may take any suitable form that is capable of functioning as a clamping mechanism. By way of example, window clamp may take the shape of a single flat sheet.
During the bonding process, the spring clamp is positioned within the center of the window of the window clamp. The spring clamp is sized such that a channel or gap is formed around the spring clamp and between the spring clamp and the window clamp. The gap is sized to allow a bonding tool to fit between the spring and window clamps. The gap's size depends on many factors, such as the type of bonding tool used and the type of bonding being performed. For example, a gap size that's in the range of about 20 to 30 mils has been found to work well.
Turning next to FIGS. 3 and 4, the arrangement of the interposer, lead frame, and lead frame clamp in accordance with the present invention will be described in the context of a bonding process. The interposer 70 sits within a cavity 92 within a heat block 90 that serves at the support member for the lead frame clamp. The lead frame 50 is positioned directly over the interposer 70, and the leads of the lead frame 50 are positioned directly on the traces of the interposer 70. During the ultrasonic bonding process, the lead frame's 50 movement relative to the interposer 70 is restrained by the lead frame clamp at two contact locales. For example, the window clamp 16 contacts the inner portion of the lead tips 52, and the spring plate 24 contacts at a point on the outer portion of the lead tips 56. The distance 56 between the spring clamp's point of contact and the lead tip may be any suitable distance; for example, 40 mils works well. The portion of the leads 54 that is located between the two contact areas is left exposed. In sum, the window clamp and spring plate are positioned directly over the lead frame, and the lead frame overlaps the interposer and a portion of the heat block 94. While the lead frame is being restrained by the window clamp and spring plate, the leads are ultrasonically bonded to the traces on the interposer. This bonding occurs within the exposed 54 portion of the lead frame 50.
The method of ultrasonic bonding in accordance with the present invention and in reference to FIGS. 3 and 4 will now be described. Initially, the interposer 70 is positioned within a cavity 92 within the heat block 90. The heat block is then heated to catalyze the bonding process. The lead frame 50 is then placed upon the interposer 70 in an overlapping position. Next, the lead frame's movement relative to the interposer is restrained at two contact locales by the window clamp 16 and the spring plate 24. After the lead frame is restrained, a lead is ultrasonically bonded to an associated trace on the interposer. While the lead frame is still clamped in two places by the lead frame clamp, the remaining unbonded leads are bonded one at a time to their associated traces.
The method of packaging of a semiconductor device will now be briefly described. First, the lead frame is formed using any available conventional processes. An interposer having a plurality of traces is then formed. The method described above in regard to ultrasonic bonding is used to bond the leads of the lead frame to the traces of the interposer. After the leads are bonded to the traces of the interposer, a die with a plurality of bonding pads is affixed to the interposer. Next, the bonding pads of the die are electrically connected to the leads of the lead frame. The die, leads, and a portion of the interposer are encapsulated using conventional encapsulation materials. Conventional techniques are used to implement these steps for packaging the semiconductor device, as are well known to those of ordinary skill in the art.
Although only one embodiment of the present invention has been described, it should be understood that the present invention may be embodied in many other specific forms without departing from the spirit or scope of the invention. Particularly, the described device may be used in conjunction with a wide variety of bonding processes, in addition to the lead frame-interposer integration process used in the example. For instance, this improvement may be applicable for any bonding process where a lead is ultrasonically bonded to an underlying substrate. For example, a lead is welded to a printed circuit board. By way of another example, a lead frame is welded to a substrate which includes a ball grid array configuration as described in commonly assigned co-pending application Ser. No. 08/496,043, entitled "THERMAL BALL LEAD INTEGRATED PACKAGE" by Mostafazadeh et al., which is incorporated herein by reference in its entirety.
Additionally, the invention has been described in relation to one example of an ultrasonic bonding configuration and method. However, it should be understood that the same types of improvement would be found when using the invention in conjunction with any suitable bonding configurations and methods. For example, this invention may be used in conjunction with the lead frame-interposer integration bonding apparatus described in the applicant's co-pending application, Ser. No. 08/613,023, now U.S. Pat. No. 5,607,096, entitled "APPARATUS AND METHOD FOR ULTRASONIC BONDING LEAD FRAMES AND BONDING WIRES IN SEMICONDUCTOR PACKAGING APPLICATIONS" which is incorporated herein by reference in its entirety.
The invention has been described in conjunction with an example wherein the lead is ultrasonically welded at a single point to the trace of an interposer. It should be appreciated that the same types of improvement would be found when bonding at more than one point on the lead. Additionally, a particular window clamp and spring clamp structure and a lead frame clamp arrangement have been described. However, the actual construction and positioned of these clamps may widely vary. For example, the spring clamp and window clamp may be separate clamps that are not attached to one another. Additionally, the window clamp and the spring clamp may both be in the form of a conventional window clamp with the spring clamp placed inside the window clamp. Therefore, the present examples are to be considered as illustrative and not restrictive, and the invention is not to be limited to the details given herein, but may be modified within the scope of the appended claims. | A lead frame clamping arrangement for lead frame/interposer bonding is disclosed that clamps the leads to be bonded at two spaced apart locations with the bonding area being positioned between the clamped portions of the particular leads being bonded. During bonding of a selected lead to its associated trace, a bonding tool tip is positioned in the gap between the clamps. In a preferred embodiment of the invention, the clamping arrangement includes a lead tip clamp and a lead arm clamp. In some embodiments, the lead arm clamp takes the form of a window clamp and the lead tip clamp includes a spring plate positioned within the window such that a channel shaped gap is formed between the spring plate and the window clamp. The gap exposes the bonding regions of all of the leads to be attached to the interposer. With this arrangement, all of the leads of a radially based lead frame can be secured to the interposer without requiring the resetting of the clamp. | 7 |
This is a divisional of co-pending application Ser. No. 07/243,170, filed on Sept. 8, 1988, which is a continuation of application Ser. No. 06/895,648, filed Aug. 12, 1986, now abandoned.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention pertains to the fields of textile manufacturing, processes for shaping or treating plastic articles, textile spinning, twisting, and twining and textiles, fluid treating apparatus.
With respect to the field of textile manufacturing, the present invention is related to the areas of (a) thread finishing by diverse finishing operations; (b) thread finishing by texturing (e.g. crimping) in which there is a control means responsive to a sensed condition; (c) thread finishing utilizing diverse texturing operations; (d) thread finishing via fluid jet having orthogonally arranged flow paths; (e) thread finishing via fluid jet having opposed reasonance chambers; (f) thread finishing via fluid jet having opposed fluid passageways.
With respect to processes for shaping or treating plastic articles, the present invention is related to the areas of: (g) processes involving twining, plying or braiding or textile fabric formation; (h) processes involving the formation of continuous or indefinite length work; (i) shaping filaments by extrusions.
With respect to textile spinning, twisting and twining, the present invention is related to the areas of (j) the strand structure of multifilament yarns wherein the filaments are crimped or bulked; (k) jet interlacing or intermingling of filaments.
With respect to the field of textiles, fluid treating apparatus, the present invention is related to the area of gas, steam, or mist treatment with continuous textile feed and discharge.
2. Description of the Prior Art
Many prior art patents are related to the process of the present invention. The closest patent is believed to be U.S. Pat. No. 4,505,013. Other patents of interest include the following U.S. Pat. Nos.: 4,355,592; 4,222,223; 3,010,270; 4,343,146; 3,953,962; 3,898,719; 3,874,045; 3,874,044; 3,811,263; 3,251,181. None of these prior art patents are believed to enable the process of the present invention. The present invention enables the continuous, high speed production of a highly and uniformly entangled multifilament carpet yarn. The prior art does not provide any means for achieving a degree and uniformity of entanglement at the process speeds of the present invention.
BRIEF SUMMARY OF THE INVENTION
The present invention is directed towards a continuous, integrated, high speed process for making a multifilament carpet yarn having a very high degree of filament intermixture. The process comprises the steps of:
(a) forwarding an undrawn multifilament carpet yarn;
(b) drawing the yarn until the elongation of the filaments has been reduced to an acceptable level for end use in carpeting applications, the drawn yarn having a denier between 2000 and 4000, the drawn filaments each having a denier between 18 and 35;
(c) crimping the drawn filaments with a jet crimping means;
(d) over-feeding the yarn to an intermixing jet, the degree of over-feeding being between 1% and 10%;
(e) intermixing the drawn, textured yarn in the intermixing jet, the intermixing jet creating a degree of entanglement of the filaments whereby a standard deviation of less than 6.0 results upon conducting a Standard Yarn Streak Potential Test; and
(f) taking up the textured, interlaced yarn at a speed of at least 800 meters per minute.
The present invention is most particularly concerned with intermixing the filaments to a very high degree. "Intermixing", as used herein is to be contrasted with entangling, interlacing and texturing. Interlacing is used to slightly entangle filaments together, so that the interlaced multifilament yarn will undergo subsequent processing with reduced flaring and individual filament wrapping. Texturing is a term used to describe mechanical deformation of filaments in order to form a textured (i.e. "crimped") filament. Both texturing and interlacing can be performed in conjunction with high speed yarn processing by using fluid jets. However, neither texturing nor interlacing creates a high degree of filament entanglement. Entangling, on the other hand, is generally utilized to create a degree of filament entanglement which is equivalent in degree to the amount of filament entanglement created by the "intermixing" process of the present invention. However, entanglement processes of the prior art have been notoriously slow, because it has never (heretofore) been possible to achieve an exceedingly high degree of filament entanglement at yarn take-up speeds in excess of about 800 meters per minute. Thus, the term "intermixing", as used herein, is defined to include only processes which enable (1) a degree of entanglement which yields a standard deviation of less than 6.0 when measured by a Standard Yarn Streak Potential Test described below while (2) the take-up speed is greater than 800 meters per minute. It has been surprisingly found that such a process is possible, and to-date the only known way of carrying out such a process is to use both supersonic steam impact on the traveling yarn along with a particular fluid jet design which will efficiently and continuously entangle the filaments to a degree which renders a standard deviation of less than 6.0 upon conducting a Standard Yarn Streak Potential Test. The process provides an additional advantage of enabling a high speed method for producing a carpet yarn which has very good tip definition in comparison with prior art carpet yarns which were made at take-up speeds below 800 meters per minute
It is an object of the present invention to provide a high speed, one-step process for intermixing the filaments of a bulked continuous filament carpet yarn.
It is a further object of the present invention to enable the high speed production of a multicolored carpet yarn having a low streak potential as measured by the Standard Yarn Streak Potential Test as defined herein.
It is a further object of the present invention to improve the degree of filament entanglement for processes having take-up speeds above 800 meters per minute.
It is a further object of the present invention to enable, at speeds greater than 800 meters per minute, the production of a bulked continuous filament yarn having a woolish look and texture.
It is a further object of the present invention to eliminate the need for commercial processes to have a plying step necessary in the production of low-streak bulked continuous filament carpet yarns.
It is a further object of the present invention to produce a bulked continuous filament carpet yarn having filaments which are entangled along their entire length rather than at nodal points.
It is a further object of the present invention to combine a plurality of yarns having different coloration potentials, while creating a product which is made both at high speed and with a low streak potential.
It is a further object of the present invention to utilize steam at supersonic speeds in order to achieve intermixing of the filaments.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic of a process of the present invention.
FIG. 2 is a schematic of an alternative process of the present invention.
FIG. 3 is a schematic of yet another alternative process of the present invention.
FIG. 4A is a longitudinal cross-sectional view of a high speed jet entangling insert of the present invention.
FIG. 4B is an exploded perspective view of the jet intermixing insert and its housing and fluid supply
FIG. 4C is a perspective cut-away view of the insert installed in the housing, together with a simulation of a yarn traveling through the intermixing insert.
FIG. 5 is another alternative process of the present invention
FIG. 6A illustrates an untrafficked, carpet made without the advantages of the present invention, while FIG. 6B illustrates the carpet of FIG. 6A after trafficking.
FIG. 7A illustrates an untrafficked carpet made with the advantages of the present invention, while FIG. 7B illustrates the carpet of FIG. 7A after trafficking.
FIG. 8 depicts a carpet yarn process in which two primary yarns are co-spun.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 illustrates, in schematic form, the process of the present invention. An undrawn feed yarn (1) is taken off of a package (2), fed through a first guide (3) and makes about 3 wraps around a first godet (4). The first godet (4) is used to pretension the yarn. The yarn is then drawn between a second godet (5) and a third godet (6). The yarn makes 7 or 8 wraps around both the second godet (5) and the third godet (6). The yarn (1), now drawn, is then texturized in a texturizing tube (7). This texturizing tube is described in U.S. Pat. Nos. 3,908,248 and 3,714,686, which are hereby incorporated by reference. The now texturized yarn (1) then travels over a direction changing roll (8) and a tensioning device (9) after which the yarn contacts a fourth godet (10) and a fifth godet (12). The texturized yarn is over-fed from the fourth godet (10) to the fifth godet (12). Between these godets (10 and 12) is an intermixing jet (11). After exiting the fifth godet the yarn (1) passes over another direction changing roller (13) and onto the traverse roll (16) of a winder (14). A yarn package (18) is then built up upon a package tube not shown, the package (18) being driven by a friction roll (15). A second package tube is to be rotated into contact with the friction roll (15) after a full package (18) is built up upon tube.
FIG. 3 illustrates a schematic of a preferred process of the present invention. In this process, eight (only four packages (2) are shown) primary, feed-yarns (1), held on packages (2), are each threaded through individual guides 3. All eight of these primary feed-yarns (1) are then passed through a second guide (19) and a preinterlacer (20), and are then fed to the pretensioning godet (4). The primary yarns (1) are then drawn between the second godet (5) and the third godet (6), and the drawn yarns (1) are then texturized in the texturizing tube. After passing over direction changing rolls 8 and 9, the yarn (1) pass around the fourth godet (10). An additional yarn (25) herein termed an "accent yarn" is merged into the drawn, texturized yarns (1) on the fourth godet (10). The accent yarn is preferably also solution dyed (i.e. pigmented). The accent yarn (25) is supplied from a package (26), the accent yarn passing through two guides (27 and 28) before going onto the fourth godet (10). Upon exiting the fourth godet (10), the yarns (1 and 25) are intermixed in the entangling jet (11). The yarns are over-fed to the intermixing jet (11) by having the surface speed of the fourth godet (10) higher than the surface speed of the fifth godet (12). The yarns (1 and 25) then pass over a direction changing guides (13) and onto winder 14, and are wound to form package 18, as described above.
FIGS. 4A, 4B, and 4C show detailed view of the intermixing jet (11) which is utilized to intermix the filaments in the process of the present invention. The intermixing jet (11) is comprised of an insert housing (29) having an insert (30) which is positioned therein. The flow of steam is partially confined by O-rings 31 and 32, these O-rings forcing the steam to travel through a slit (33) in the insert (30), i.e., the O-rings 31 and 32 preventing the steam from escaping between the housing (29) and the insert (30). The insert (30) is locked into place with a setscrew (34), and steam is supplied to the housing via an opening (not shown) to which is attached a threaded connector (35). The slit (33) in the insert (30) is approximately 1.4 millimeters wide, and preferably extends approximately 180 degrees around the circumference of the insert. As a result of the shape of the slit (33), the yarn traveling through the intermixing jet (11) cannot escape continuous impingement of supersonic steam which is entering the yarn-impact chamber 36 via slit 33. The shape of the slit (33) creates an inescapable flow of steam. It is believed that this inescapable flow is largely responsible for the "continuous intermixing" (to be distinguished from "nodal entanglement") produced by the present invention. Nodal entanglement creates spaced regions of high filament entanglement between which are regions virtually free of filament entanglement. The "continuous intermixing" form of entanglement produced by the process of the present invention contrasts with nodal entanglement in that the filaments are entangled along the entire length of the yarn, there being no regions without a fairly high degree of filament entanglement.
The process of the present invention is "continuous" in time. That is, the process carries out drawing, texturizing, and intermixing all at once. In contrast, commercial prior art processes have utilized a separate and expensive plying step in order to create a carpet yarn which had a low streak potential, as measured by the test described below.
The process of the present invention is "intergrated" in that the steps of drawing, texturizing, and intermixing are carried out in a single operation rather than as separate operations which require separate yarn winding steps. Prior art commercial processes which utilizing plying to create a low streak-potential product also require an additional winding step, which increases manual handling, energy consumption, and costs.
The process of the present invention is "high speed" in that the yarn must be taken up at a speed of at least 800 meters per minute. Prior art processes which have produced a jet-entangled yarn having a streak-potential as low as that of the present invention have operated at significantly lower speeds--i.e., below 800 meters per minute and generally between 100 and 500 meters per minute. This is because the prior art has not had the means to create a high degree of continuous filament intermixing at a high speed.
"Crimping" has been defined above as mechanical deformation of filaments in order to form a texturized filament Although the crimping may be carried out in a variety of manners, it is most preferable that the process utilize the crimping tubes taught in U.S. Pat. Nos. 3,908,248 or 3,714,686.
The process illustrated in FIG. 1 can be carried out with an uncolored, dyeable feed yarn, with a dyed feed yarn, or with a precolored (pigmented) feed yarn. The high degree of intermixing (for a yarn of only a single color) provides the advantage of producing, at high speed, a yarn which will show delayed "ugly-out" when made into a cut pile carpet. "Ugly-out" is a term used to describe the loss of tip definition caused by heavy traffic on the carpet. Heavy traffic causes the filaments of each yarn to flair out, causing a "mushy" and "indistinct" look which is undesirable. It has been found that the intermixed yarn, when made by the process described herein, tolerated more traffic while exhibiting less ugly-out than carpets made from carpet yarns which had been entangled to a lesser degree.
The process of the present invention is advantageously carried out as shown in FIG. 2. The greatest assets of the present invention lie in its advantages for combining yarns which have significantly different coloration potentials. The high degree of entanglement of textured yarns produces a yarn which not only exhibits delayed ugly-out, but also has fewer streaks than prior art carpet yarns produced at similar speeds without a plying step. Streaking is always a problem with bulk continuous filament carpet yarn comprising filaments of substantially different coloration, and it has long been the practice to ply two yarns together in order to reduce the potential for streaking to result. The plying operation is an additional step and is time consuming and expensive. The process shown in FIG. 2 may utilize, for example, one white (undyed) polyamide primary feed yarn (1) which is acid dyeable, one black (pigmented) polyamide tonal primary feed yarn (21) and a fully drawn, untextured, red (pigmented) accent yarn (25). The combined yarns, once wound onto the package (18), will appear as a grey yarn (tonal yarn mixed evenly with the white feed yarns) along with a red accent yarn which stays bundled together (i.e. is not intermixed). In a carpet made from this yarn, if the white yarn was left undyed the carpet would appear to have a grey base and a red "berber" effect. The grey is created by the high degree of mixing of black and white filaments and the red "berber" effect is created by the lack of mixing of the red filaments with either the black or white filaments. The entangling jet (11) has been found to effectively intermix only the crimped filaments. The untextured filaments of the accent yarn (25) are not intermixed by the entangling device (11). Rather, these filaments remain relatively intact as a bundle. It has been theorized that it is the excessive length (i.e., potential slack) present in crimped yarns together with the fullness (i.e., low density) present in crimped yarns which allows the impact of a fluid stream to create a greater degree of filament entanglement than with uncrimped yarns.
The present invention is most useful in the manufacture of bulked continuous filament carpet yarns which, when drawn, have a denier between 2000 and 4000, the drawn filaments each having a denier between 18 and 35.
The present invention pertains to a process which intermixes drawn, textured filaments in the intermixing jet, the intermixing jet creating a degree of intermixing of the filaments whereby a standard deviation of less than 6.0 results upon conducting a Standard Yarn Streak Potential Test. The Standard Yarn Streak Potential Test is conducted as follows:
Two primary feed yarns are drawn, textured, intermixed, and wound onto a package. One of the feed-yarns is a 9100 denier (before drawing), 135 filament semi-dull bulked continuous filament white yarn. The other feed yarn is a 2625 denier (before drawing) 42 filament black bulked continuous filament feed-yarn. The resulting drawn (by a factor of 3.2×), textured, intermixed, wound product is used to make a 0.1 guage, level loop, 28 ounce/square yard carpet having a pile height of 3/16 inches. The carpet is tested by making colorimetric measurements with the Small Angle View attachment on a Macbeth 1500 colorimeter at between 65 and 100 different locations on the carpet. The Macbeth 1500 colorimeter analyzed an area of approximately 2 cm×1 cm, this area being oriented in the direction of tufting (i.e., along the length of the yarn). The values obtained were averaged to establish a standard reference point. Then another 35 to 50 additional measurements were made and compared against the standard reference point. The DL's were recorded, from which a standard deviation was calculated. The standard deviation is a quantitative measurement of the degree of color mixing obtained in the sample. It should be emphasized that the Standard Yarn Streak Potential Test requires that: (1) the yarns used are: (a) a drawn and textured 2600 denier/135 filament semi-dull white yarn, and (b) a 750 denier/42 filament black yarn; and (c) that the standard reference point and the 35 to 50 additional measurements are made on the same type of carpet as described above and that the measurements are taken in the same manner as described above.
The Standard Yarn Streak Potential Test can be carried out in order to determine whether any process which draws, texturizes, and intermixes via fluid jet will create a product having a standard deviation of less than 6.0. One must simply substitute the feed-yarns (described above) into the process, make the carpet according to the description above, and analyze the carpet as described above. It is most preferred that the degree of intermixing is high enough so that the resulting standard deviation is less than 5.0.
It has been determined that the intermixing jet utilized in the present invention should have a yarn-impact chamber (36, as shown in FIG. 4A) diameter between 3/64 inches in diameter and 3/16 inches in diameter It has also been found that the length to diameter ratio within the yarn-impact chamber (36) is most preferably 2.4. It has been found that an L/D of 2.0 does not result in sufficient intermixing and that an L/D of 2.8 results in a product having too much "stiffness" (i.e., a harsh hand). The slot (33) is most preferably about 0.044 inches wide and most preferably extends 180 degrees around the yarn-impact chamber, creating an "inescapable" jet of fluid to impact the yarn in the yarn-impact chamber. It has been found that the supersonic flow of steam causes the creation of filament loops when the steam impacts the yarn traveling through the intermixing device. These loops create a "wool like" appearance in the resulting product.
The process of the present invention may additionally comprise the step of extruding the primary yarns immediately prior to forwarding the primary yarns to the second godet (5). This creates the advantageous economic effect of elimination of the winding step used to make the packages (2, 22 and 26) shown in FIG. 2. In addition, although the accent yarn is generally thought to provide a desired coloration effect, one could utilize an antistatic yarn in order to impact an antistatic characteristic to the resulting product. The antistatic yarn (or the accent yarn, for that matter) could be a multifilament or a monofilament, and could be predrawn and pretextured or merely predrawn and untextured.
EXAMPLE 1
The process was carried out as shown in FIG. 2. A 6700 denier, 58 filament, undrawn nylon-6 white feed yarn (1) was fed from a package (2) through two guides (3 and 19), following which the feed yarn (1) came into contact with a pretensioning godet (4). As used herein, the term "godet" is meant to include both the large driven roll along with the smaller "idler" roll. When the yarn is described as being "wrapped around the godet", it is, of course, meant that the yarn is wrapped around the driven roll and the idler roll as a pair, rather than being wrapped more than 1 full circumference around any single roll.
A 726 denier 14 filament, undrawn (approximately 460% elongation to break), nylon-6, black "tonal" yarn (21) was taken from a second package (22), this yarn also passing through two guides (23 and 24) before merging into the white yarn (1) on the pretensioning godet (4). After making three wraps on the pretensioning godet, the combined feed and tonal yarns (1 and 21) made seven wraps around a second godet (5). The second godet (5) was maintained at a temperature of approximately 50° C. The surface speed of the second godet (5) was 372 meters per minute. The yarns (1 and 21) then made seven wraps around a third godet (6) having a surface speed of 1200 meters per minute and a temperature of 160° C. Of course, the yarns (1 and 21) were drawn approximately 3.2× between the godet (5) and the third godet (6). Upon contacting the third godet (6), an antistatic yarn (40), supplied from a yarn package (41) was merged into contact with the now drawn yarns (1 and 21). The antistatic yarn (40), the feed yarn (1), and the tonal yarn (21) were then texturized in a texturizing tube (42) similar to those described in U.S. Pat. Nos. 3,908,248 and 3,714,686. The texturizing tube was supplied with hot air (450° C.) at a pressure of 85 psi (source of hot air not shown). After texturing, the combined feed yarn (1), tonal yarn (21), and antistatic yarn (40) were passed partially around a direction changing roll (8) and then around a tensioning device (9), and finally around a fourth godet (10). The surface speed of the fourth godet was 905 meters per minute. A 220 denier, 14 filament, nylon-6, red "accent" yarn (25), supplied from a package (26), was then merged into contact with the already combined and texturized yarns 1, 21 and 40. After making 5 wraps around the fourth godet (10), the now combined yarns (1, 21, 40 and 25) were passed through an intermixing jet (11). The intermixing jet had a 180 degree slit which was 0.044 inches wide, this slit being supplied with saturated steam (177° C.) at 120 psig. The intermixing jet had a yarn-impact chamber which had a length of 0.3 inches and a diameter of 0.125 inches, and the intermixing jet was proportioned as shown in FIG. 3A. The impact of the steam on the traveling yarns created a high degree of filament entanglement between the feed yarn (1) and the tonal yarn (21) and also created filament loops which protruded from the highly entangled filaments at random intervals. The accent yarn was tied into the remaining filaments, but was not intimately mixed thereinto. The now intermixed yarns (43) then made 5 wraps around a fifth godet (12). The surface speed of the fifth godet (12) was 860 meters per minute The intermixed yarns (43) then passed around a direction changing roll (13) and were then wound to form a package (18) on a Rieter winder, Model JT/A, (14), at a speed of 864 meters per minute. The fourth and fifth godet pairs (10 and 12) were not heated, i.e. they were kept at room temperature. The yarn tension at specific points (A-G, as shown in FIG. 1) in the process was as follows:
______________________________________Designated TensionPoint in Process (Total, in Grams)______________________________________(a) 6000(b) 80(c) 10(d) 40(e) 10(f) 100(g) 140______________________________________
The resulting product was a yarn having textured, very evenly mixed white and black filaments together with a bundle of untextured, unmixed red filaments. When made into a carpet, the yarn appeared, from a distance, to be heather grey with flecks (i.e. points) of red randomly dispersed to give a berber effect. The white feed-yarn (1) could then be dyed in any of a wide variety of colors, as desired.
EXAMPLE 2
The process was carried out as shown in FIG. 1. An 1800 denier, 99 filament, undrawn, nylon-6 white feed-yarn (1) was fed from a package (2) through a guide (3) and onto a pretensioning godet (4), where the yarn was wrapped around the godet three times. The undrawn yarn had a elongation to break of approximately 460%. The yarn (1) was then wrapped seven times around a second godet (5), this second godet (5) being maintained at a temperature of 50° C. The second godet pair had a surface speed of 372 meters per minute. The yarn was then drawn between the second godet (5) and a third godet (6), which the yarn was wrapped around a total of seven times. The third godet (6) had a surface speed of 1200 meters per minute and was maintained at a temperature of 160° C. Upon exiting the third godet (6), the now drawn yarn (1) entered a texturing tube as described in Example 1. The texturizing tube was supplied with hot air (450° C.) at a pressure of 85 psi. After texturizing, the now drawn and texturized feed yarn (1) was passed partially around a direction changing roll (8) and then around a tensioning device (9), and finally around a fourth godet (10). The fourth godet (10) was not heated (i.e. was at room temperature) and was maintained at a surface speed of 880 meters per minute. After making 5 wraps around the fourth godet (10), the yarn (1) next passed through an intermixing jet (11). The intermixing jet had a 180 degree slit which was 0.044 inches wide, this slit being supplied with saturated steam (177° C.) at 120 psig. The intermixing jet (11) had a yarn-impact chamber which had a length of 0.3 inches and a diameter of 0.125 inches, and the intermixing jet was proportioned as shown in FIG. 3A. The impact of the steam on the traveling multifilament yarn created a high degree of filament entanglement and also created filament loops which protruded from the highly entangled filaments at random intervals. The yarn (1) then made 5 wraps around a fifth godet (12). The surface speed of the fifth godet (12) was 860 meters per minute. The yarn (1) then passed around a direction changing roll (13) and was then wound to form a package (18) on a Rieter Winder, Model JT/A, (14), at a speed of 875 meters per minute. The fourth and fifth godet pairs (10 and 12) were not heated, but instead were kept at room temperature. The yarn tension at specific points (A-G, as shown in FIG. 3) in the process was as follows:
______________________________________Designated Point Tensionin Process (Total, in Grams)______________________________________(a) 3000(b) 80(c) 10(d) 40(e) 10(f) 100(g) 140______________________________________
EXAMPLE 3
The process was carried out according to the schematic illustrated in FIG. 3. Eight 1089 denier, 14 filament undrawn precolored nylon-6 feed yarns (1) were feed from eight packages (2). Only four of the eight packages are shown in FIG. 3. Four of the eight yarns were brown, two yarns were beige, one yarn was orange, and one yarn was white. Each of the yarns (1) was first threaded through an individual guide (3), following which all eight yarns (1) were together threaded through a group guide (19). The feed yarns (1) were then directed through a preinterlacer (20). The preinterlacer (20) was supplied with compressed air at approximately room temperature and at a pressure of 150 psig. The preinterlacer (20) had a circular yarn throughout passageway 0.1875 inches in diameter and 0.30 inches long. The preinterlacer had three jet orifices, each of which intersected the axis of the yarn throughput orifice at an angle of 90 degrees. The axes of the three jet orifices were in a single plane and were positioned equidistantly from one another so that there was no net directional effect on the yarns being preinterlaced. Each jet orifice had a diameter of 0.0625 inches. After passing through the preinterlacer (20), the feed yarns (1) came into contact with a first (pretensioning) godet (4). After making three wraps around the first godet (4), the combined feed yarns (1) made seven wraps around a second godet (5). The second godet had a surface speed of 372 meters per minute and was heated to a temperature of 50° C. From here, the yarns (1) made ten wraps around a third godet (6), the third godet (6) having a surface speed of 1200 meters per minute and a temperature of 160° C. The yarns (1) were drawn 3.23× between the second godet (5) and the third godet (6). The yarns (1) were texturized in a texturing tube (7) similar to those described in U.S. Pat. No. 3,908,248 and 3,714,686. The texturizing tube was supplied with hot air (450° C.) at a pressure of 85 psi. After texturizing, the feed yarns (1) were passed partially around a direction changing roll (8) and then around a tensioning device (9), and finally made 5 wraps around a fourth godet (10). An antistatic yarn (25), supplied from a package (26), was merged with the feed yarns (1) on the fourth godet (10). The fourth godet was unheated, and had a surface speed of 905 meters per minute. The combined yarns (1, and 25) then passed through an intermixing device (11) and then made 5 wraps around a fifth godet (12) which had a surface speed of 860 meters per minute and was also unheated. From here the combined yarns (1, and 25) passed over a direction changing roll (13) and finally were taken up on a Rieter Winder, Model JT/A, (14), at a speed of 868 meters per minute. A yarn package (18) was formed by the winder (14). The yarn tension at specific points (A-G, as shown in FIG. 3) in the process was as follows:
______________________________________Designated Point Tensionin Process (Total, in Grams)______________________________________A 5000B 80C 10D 40E 10F 100G 140______________________________________
In the process described above, the intermixing jet was substantially as shown in FIGS. 3A, 3B, and 3C. The jet (11) had an 180 degree slit which was 0.044 inches wide, this slit being supplied with saturated steam (at 177° C.) at 120 psig. The jet (11) had a yarn-impact chamber which had a length of 0.3 inches and a diameter of 0.125 inches, and the intermixing jet was proportioned as shown in FIG. 3A. The product exhibited a very high degree of entanglement of the filaments, and filament loops also protruded from the resulting product
EXAMPLE 4
This example is intended to show how the Standard Yarn Streak Potential Test may be applied to a process in order to determine the standard deviation which the process is capable of producing. A process (carried out as shown in FIG. 5) was subjected to the Standard Yarn Streak Potential Test in order to determine whether the resulting standard deviation was less than 6.0.
Two primary feed yarns (1 and 21) were drawn, textured, intermixed, and wound onto a package. The first feed yarn (1) was a 9100 denier (before drawing), 135 filament semidull (0.3 percent TiO 2 ), continuous filament, white polycaprolactam yarn. The second feed yarn (21) was a 2625 denier (before drawing), 42 filament, black continuous filament polycaprolactam feed yarn. These yarns were drawn, textured, intermixed, and taken up under the conditions described in Example 2. Thus, Example 4 is, in effect, a description for subjecting the process of Example 2 to the Standard Yarn Streak Potential Test. The resulting product was used to make a 0.1 gauge, level loop, 28 ounce per square yard carpet having a pile height of 3/16 inches. The carpet was tested by making colorimetric measurements with the Small Angle View attachment on a Macbeth 1500 colorimeter. Measurements take by the colorimeter represented the percent of light reflected upon subjecting a portion of the carpet to a given amount of light. Measurements were taken at 50 different locations on the carpet. The Macbeth 1500 colorimeter measured an area of approximately 2 centimeters by 1 centimeter, this area being oriented in the direction of tufting (i.e. along the length of the yarn). The values obtained were averaged in order to establish a standard reference point. After calculation of the standard reference point, another 75 measurements were made, each being compared with the standard reference point. The DL's were recorded (the DL's were based on the CIELAB color order system), and a standard deviation of 5.34 was calculated.
EXAMPLE 5
This example is intended to show how the Standard Yarn Streak Potential Test may be applied to a process similar to that discussed in Example 4. The process was carried out as shown in FIG. 5 and as described above in the process description related to FIG. 5. However, in place of the intermixing device (11), a conventional interlacer was utilized. The interlacer used was exactly the same as the preinterlacer (20) utilized in FIG. 3. However, in this Example, the interlacer (2)) of FIG. 3 was used in place of the intermixing device (11) of FIG. 5. The interlacer (20) was made and operated at the same specifications described in Example 3. Again, two primary feed yarns were drawn and textured exactly as in Example 4. The feed yarns were identical to those used in Example 4. The interlacer was supplied with compressed air at 150 psig. The resulting product was used to make a carpet of the same specifications as described in Example 4. Colorimetric measurements were taken exactly as described in Example 4. A standard deviation of 9.27 resulted.
A comparison of Examples 4 and 5 illustrates the need for the use of a device which is capable of intermixing the filaments rather than interlacing the filaments. A visual examination of the carpet produced in Example 4 revealed that the carpet produced via Example 4 exhibited a "solid heather" appearance. In contrast, a visual examination of the carpet produced via Example 5 revealed that the carpet produced via Example 5 exhibited a "random stria" appearance. It has been conceived that any carpet exhibiting a standard deviation of less than 6.0 (as measured by the test) will also exhibit a "solid heather" appearance, while any carpet exhibiting a standard deviation of greater than 9.0 (again, as measured by the test) will also exhibit a "random stria" appearance. The low streaking present in the solid heather carpets is considered to be highly desirable, and has been achieved in the past using both relatively low speed processes and plying processes.
FIGS. 6A and 6B illustrate the effect of traffic on a carpet made using prior art technology. The carpet is new in FIG. 6A, while FIG. 6B illustrates the same carpet after 133,000 "traffics". FIG. 7A and 7B illustrate a carpet which is identical to the carpet of FIGS. 6A and 6B, except that the carpet shown in FIGS. 7A and 7B utilized an intermixing step in the yarn production process. FIG. 7A represents this carpet when new and FIG. 7B represents this carpet after 133,000 "traffics". A comparison of FIG. 6B with FIG. 7B illustrates the dramatic difference in tip definition after heavy trafficking. Obviously, the carpet made with the intermixed yarn (FIG. 7B) was far more durable in terms of tip definition (i.e. "ugly-out") than the carpet illustrated in FIG. 6B, which was made using a prior art interlaced yarn which had 10-12 nodes per meter.
FIG. 8 depicts a process in the manner of FIG. 5, except the carpet yarns are co-spun in a single process. Primary feed yarn 101 is spun from a conventional spinning device 102. A second feed yarn 103 of different characteristics is spun from spinning device 104. The two yarns are converged through eyelet guides 3 and 19 prior to being contacted by pretensioning godet 4. The combined yarns are then drawn between godets 5 and 6, textured in device 42, intermixed in jet 11 and wound into a package 15.
The carpets shown in FIGS. 6A and 6B are velvet plush (cut loop) carpets having a pile height of 3/8 inches, and 48 oz./square yard of face yarn. The yarns used in both carpets consisted of: (a) an 1800 denier nylon-6 bulked continuous filament space dyed yarn, which was plied with (b) two ends of 2000 denier, stock dyed, nylon-6 spun yarn. The spun yarns were each made from 8 inch burgundy colored staple. Each of the spun yarns had 31/2 twists per inch, and the plying process inserted 11/2 twists per inch into the final yarn. The space dyed yarn was dyed black and brown. In the carpet shown in FIG. 5A, the 1800 denier space dyed yarn was interlaced so that it contained 10-12 nodes per meter, while in the carpet shown in FIG. 7A, the 1800 denier space dyed yarn was intermixed so that it had virtually continuous filament entanglement.
FIGS. 5A, 5B, 7A and 7B illustrate the fact that the process of the present invention is capable of making a yarn at high speed which has improved tip definition over prior art carpets which are made at high speed with entanglement via interlacing. Improved tip definition is an improvement for any carpet, i.e. both solid an multicolored carpets. The reason for using multicolored yarns in FIGS. 5A and 7A was simply for purposes of making the improved tip definition more conspicuous. | A continuous, high speed (greater than 800 meters per minute) process and apparatus enable the production of a multifilament carpet yarn having a degree of filament intermixture high enough so that a standard deviation of less than 6.0 results upon conducting a Standard Yarn Streak Potential Test, as described herein. The apparatus and process allow the production of a multicolored carpet yarn which exhibits a reduced tendency to streak and an increased retention of tip definition. | 3 |
This application is a continuation of application Ser. No. 125,511, filed Nov. 25, 1987, now abandoned.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a polyimide resin known as a heat-resistant resin and, more particularly, to a novel copolyimide possessing excellent thermal dimensional stability and mechanical properties.
2. Description of the Prior Art
Polyimides are well known as polymers having excellent heat resistance. These polymers also have good resistance to chemicals, as well as having good electrical and mechanical characteristics. A typical polyimide is a polymer prepared by means of condensation polymerization, using 4,4'-diaminodiphenyl ether and pyromellitic dianhydride, and which is commercially available in quantity. This polymer is used as an electrical material requiring heat resistance, such as a flexible printed circuit board. Although the polymer has good mechanical characteristics such as high tensile properties, its thermal dimensional stability is poor (linear thermal expansion coefficient: 3×10 -5 ° C. -1 ), which leads to problems such as warping and curling of flexible printed circuit boards. A flexible printed circuit board comprises a polyimide film and a metal laminated thereon. Since the linear thermal expansion coefficient of the metal is less than that of the polyimide film, warping and curling occur due to changes in temperature during the fabrication and subsequent use of the flexible printed circuit boards.
Another problem caused by poor thermal dimensional stability of polyimide is warping or curling of a magnetic recording material. A recent high-density magnetic recording material is fabricated by depositing a metal on a base film. Since metal deposition is performed at a high temperature, a heat-resistant polymer such as a polyimide should preferably be used as the base film. However, since the linear thermal expansion coefficient of the polyimide film is greater than that of the metal, undesirable warping and curling inevitably occur.
Since polyimides have good heat resistance, they receive a great thermal influence. Consequently, demand has arisen for the fabrication of a polyimide which possesses excellent thermal dimensional stability. With the advent of electronics, in particular, demand for such has only become stronger.
Examples of a polyimide having excellent thermal dimensional stability are disclosed in Japanese Patent Disclosure (Kokai) Nos. 61-158025, 61-181828, 61-241335, and 61-264028. In the polyimides disclosed in Japanese Patent Disclosure (Kokai) Nos. 61-158025 and 61-264028, biphenyltetracarboxylic dianhydride and pyromellitic dianhydride (the latter is used if necessary) are used as tetracarboxylic dianhydrides, and paraphenylene diamine and 4,4'-diaminodiphenyl ether (the latter is used if necessary) are used as diamines. These materials are polycondensed to obtain the above polyimides. The polyimide disclosed in Japanese Patent Disclosure (Kokai) No. 61-181828 is prepared by using a specific heterocyclic diamine (e.g., 2,5-diaminopyridine) as diamine and polycondensing it with an aromatic tetracarboxylic dianhydride. The polyimide disclosed in Japanese Patent Disclosure (Kokai) No. 61-241325 is prepared by using 9,9-bis(4-aminophenyl)anthracene and paraphenylene diamine as diamines and polycondensing them with biphenyltetracarboxylic dianhydride as a tetracarboxylic dianhydride. These polyimides are prepared by using expensive compound materials such as biphenyltetracarboxylic dianhydride, heterocyclic diamine, or 9,9-bis(4-aminophenyl)anthracene.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a polyimide which has excellent thermal dimensional stability, and which can be fabricated by using conventional inexpensive materials.
It is another object of the present invention to provide a polyimide having excellent thermal dimensional stability and mechanical properties.
It is still another object of the present invention to provide a polyimide which has excellent mechanical properties and is free from warping or curling when a film composed of this polyimide is bonded to a metal.
According to the present invention there is provided a copolyimide characterized in that the copolyimide contains units represented by formulas (I) and (II) ##STR2## (wherein R 0 represents an aromatic tetracarboxylic residue) and is prepared by use of a method characterized by including the steps of:
(a) synthesizing an amic acid prepolymer of acid anhydride group terminals or amino group terminals, by causing an aromatic tetracarboxylic dianhydride to react with a diamine containing 4,4'-diaminophenyl ether and/or paraphenylene diamine at a non-equimolar ratio;
(b) synthesizing polyamic acid having units represented by formula (III) and (IV); ##STR3## by using the amic acid prepolymer as part or all of the diamine or the acid dianhydride; and
(c) dehydrating the polyamic acid to synthesize the polyimide.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
An example of a copolyimide of the present invention is one prepared by means of a method which employs the step (a) of synthesizing an amic acid prepolymer of amino group terminals by using a diamine in a molar ratio of more than 1 with respect to an aromatic tetracarboxylic dianhydride. For example, 10 to 90 mol% of aromatic diamine (A with respect to the total diamine is caused to react with 40 to 99 mol% of an aromatic tetracarboxylic dianhydride, with respect to the aromatic diamine (A) in an organic solvent, to obtain the amic acid prepolymer of the amino group terminals. 90 to 10 mol% of aromatic diamine (B) with respect to the total diamine is added to the amic acid prepolymer solution, and the aromatic tetracarboxylic dianhydride is added thereto in such an amount that the total diamine is equimolar with the total aromatic tetracarboxylic dianhydride, whereby copolyamic acid is obtained.
The copolyamic acid solution is casted or coated to form a copolyamic acid film. The film is then dried, and the copolyamic acid is thermally or chemically dehydrated to close the ring (i.e., conversion into an imide). In this way, a copolyimide excellent in dimensional stability and mechanical properties is obtained.
Both 4,4'-diaminodiphenyl ether and paraphenylene diamine are used as indispensable amine components. Diamine (A) or diamine (B) can be 4,4'-diaminodiphenyl ether or paraphenylene diamine, or a mixture thereof. Although it is preferable to use 4,4'-diaminodiphenyl ether and paraphenylene diamine for the diamine component, other amines may be used together with these indispensable amines. When other such amines are used, it is desirable to use 4,4'-diaminodiphenyl ether and paraphenylene diamine in an amount such that the content of momomer units represented by formulas (I) and (II) falls within the range of 50 wt% or more, preferably 80 wt% or more, and more preferably 90 wt% or more in the polyimide molecules.
Another example of a copolyimide of the present invention is one prepared by means of a method which employs the step (a) of synthesizing an amic acid prepolymer of acid anhydride group terminals by using an aromatic tetracarboxylic dianhydride in a molar ratio of more than 1 with respect to a diamine. For example, an aromatic tetracarboxylic dianhydride is caused to react with aromatic diamine (A) in an organic polar solvent at a mole ratio greater than 1, thereby to obtain an amic acid prepolymer having an acid anhydride group at its terminals. Subsequently, aromatic diamine (B) is added to this solution, in an amount such that the total diamine is equimolar with the aromatic tetracarboxylic dianhydride, and reacted to prepare copolyamic acid. Following the same procedures as described above, the copolyamic acid film is produced. The film is then dried, and the copolyamic acid is thermally or chemically dehydrated to close the ring (i.e., conversion into an imide). In this way, a copolyimide excellent in dimensional stability, and mechanical properties is produced. Both 4,4'-diaminodiphenyl ether and paraphenylene diamine are used as indispensable amine components. Diamine (A) or diamine (B) can be 4,4'-diaminodiphenyl ether or paraphenylene diamine, or a mixture thereof. Although it is preferable to use 4,4'y-diaminodiphenyl ether and paraphenylene diamine for diamine component, other amines may be used together with these in dispensable amines. When such other amines are used, it is desirable to use 4,4'-diaminodiphenyl ether and paraphenylene diamine in an amount such that the content of momoner units represented by formulas (I) and (II) falls within the range of 50 wt% or more, preferably 80 wt% or more of such amines, and more preferably 90 wt% or more in the polyimide molecules.
In the polyimide of the present invention, the repetition unit based on paraphenylene diamine represented by formula (I) and the repetition unit based on 4,4'-diaminophenyl ether represented by formula (II) are regularly and uniformly distributed in the molecular chain. As a result, a polyimide excellent in thermal dimensional stability and mechanical properties can be obtained. The polyimide of the present invention is excellent in thermal dimensional stability and mechanical properties as compared with a copolyimide prepared by random polymerization, using paraphenylene diamine and 4,4'-diaminodiphenyl ether as diamines, or a mixture of a homopolymer of a polyimide prepared by using paraphenylene diamine as a diamine and a homopolymer of a polyimide prepared by using 4,4'-diaminodiphenyl ether. The polyimide of the present invention has an elongation of 20% or more for a linear thermal expansion coefficient of 2.5 ×10 -5/ ° C. or less (at 50° C. to 300preferably 40% or more for 2.0 ×10 -5/ ° C. or less, and more preferably 50% or more for 1.5 ×10 -5/ ° C. Further the polyimide of the present invention has an appropriate modulus.
Polyamic acid and a polyimide which are prepared in the case of the present invention are polymers having the following repetition units. ##STR4## (wherein each of R 1 and R 2 independently represents a diamine residue selected from 4,4'-diaminodiphenyl ether and paraphenylene diamine, R 0 represents a tetracarboxylic residue, and each of m and n independently represents a positive integer). The values of m and n are preferably constant throughout the molecular chain. In particular, when an amic acid prepolymer of the acid anhydride group terminals is used, n or m can be set to be 1 throughout the entire molecular chain. The resultant polyimide is excellent particularly with regard to its mechanical properties. The molecular weight of a copolyimide of the present invention is not limited to a specific value. In favor of physical properties, however, the number average molecular weight preferably falls within the range of 50,000 or more, more preferably 80,000 or more, in particular 100,000 or more, and most preferably 120,000 or more.
Indispensable aromatic diamine components used in the present invention are 4,4'-diaminodiphenyl ether and paraphenylene diamine.
The molar ratio of 4,4'-diaminodiphenyl ether to paraphenylene diamine falls within the range of 1/9 to 9/1, preferably 1/7 to 7/1, and more preferably 1/4 to 4/1.
Examples of the aromatic tetracarboxylic dianhydride are pyromellitic dianhydride, 3,3',4,4'-biphenyltetracarboxylic dianhydride, 3,3',4,4'-benzophenone tetracarboxylic dianhydride, naphthalene-1,2,5,6-dianhydride. These aromatic tetracarboxylic dianhydride components can be used singly or as a mixture. Among these tetracarboxylic dianhydride, pyromellitic dianhydride is preferred.
It is desirable to use pyromellitic dianhydride in an amount such that the content of pyromellitic dianhydride in the total tetracarboxylic dianhydride is 50 wt% or more, preferably 70 wt% or more, and especially 90 wt% or more. In addition to the abovementioned diamine component diamine compounds represented by the following formula:
H.sub.2 N-R-NH.sub.2
(wherein R is an organic group having a valency of 2) Examples of these diamines are 4,4'-bis(4-aminophenoxy) biphenyl, 4,4'-diaminodiphenylsulfone, 3,3'-diaminodiphenylsulfone, bis[4-(4-aminophenoxy)phenyl]sulfone, bis[4-(3-aminophenoxy)phenyl]sulfone, bis[4-(2-aminophenoxy)phenyl]sulfone, 1,4-bis(4-amin benzene, 1,3-bis(4-aminophenoxy)benzene, 1,3-bis(3-aminophenoxy)benzene, 1,4-bis(4-aminophenyl) benzene, bis[(4-aminophenoxy)phenyl]ether, 4,4'-diaminodiphenyl methane, bis(3-ethyl-4-aminophenyl) methane, bis(3-methyl-4-aminophenyl)methane, bis(3-chloro-4-aminophenyl)methane, 3,3'-dimethoxy-4,4'-diaminodiphenyl, 3,3'-dimethyl-4,4'-diaminobiphenyl, 3,3'-dichloro-4,4'-diaminobiphenyl, 2,2',5,5'-tetrachloro-4,4'-diaminobiphenyl, 3,3'-dicarboxy-4,4'-diaminobiphenyl, 3,3'-dihydroxy-4,4'-diaminobiphenyl, 4,4'-diaminodiphenylsulfide, 3,3'-diaminodiphenyl ether, 3,4'-diaminodiphenyl ether, 4,4'-diaminobiphenyl, 4,4'-diaminooctafluorobiphenyl, 2,4-diaminotoluene, methaphenylene diamine, 2,2-bis[4-(4-aminophenxy)phenyl]propane, 2,2-bis[4-(4-aminophenoxy)phenyl]hexafluoropropane, 2,2-bis(4-aminophenyl)propane, 2,2-bis(aminophenyl)hexafluoropropane, 2,2-bis(3-hydroxy-4-aminophenyl)propane 2,2-bis(3-hydroxy-4-aminophenyl) hexafluoropropane, 9,9-bis(4-aminophenyl)-10-hydro-anthoracene, and orthotolidinesulfone. In addition, some multivalent amine compounds such as 3,3',4,4'-biphenyltetraamine, and 3,3',4,4'-tetraaminodiphenyl ether can also be used.
According to the present invention, a method of adding monomers for polymerization is most important. When the amic acid prepolymer of amino group terminals is used as an intermediate, the amount of diamine (A) used in step (a) containing 4,4'-diaminodiphenyl ether and/or paraphenylene diamine falls within the range of 10 to 90 mol%, preferably 15 to 85 mol%, and more preferably 20 to 80 mol% with respect to the total amount of diamine component. 40 to 99 mol% of the aromatic tetracarboxylic dianhydride with respect to the amount of diamine (A) is caused to react therewith, to obtain an amic acid prepolymer of amino group terminals. To the amic acid prepolymer solution of the amino group terminals, 90 to 10 mol%, preferably 85 to 15 mol%, and more preferably 80 to 20 mol% of diamine (B) used in the step (b) with respect to the total diamine amount and the aromatic tetracarboxylic dianhydride in a equimolar amount to the total amount of diamine are added and reacted therewith, to prepare copolyamic acid. When the amic acid prepolymer of acid anhydride group terminals is used as an intermediate, 50 to 90 mol%, preferably 50 to 87.5 mol%, and more preferably 50 to 80 mol% of diamine (A) used in step (a) containing 4,4'-diaminodiphenyl ether and/or paraphenylene diamine, with respect to the amount of the acid anhydride used in the step (a), are added to the aromatic tetracarboxylic acid dianhydride, to prepare an amic acid prepolymer of acid anhydride group terminals. Diamine (B) used in step (b) is added at an equimolar ratio to the acid anhydride in the prepolymer solution, so as to obtain copolyamic acid.
Examples of intermediates such as amic acid prepolymers of the amino group terminals and the acid anhydride group terminals are compounds represented as follows: ##STR5## (wherein R 0 is as defined above.) The intermediate may be polyamic acid having a low molecular weight having the amino or acid anhydride group terminals. The number average molecular weight of the amic acid intermediate is less than copolyamic acid as the final product, and is preferably 20,000 or less, and more preferably 10,000 or less.
Examples of the organic solvent used in the reaction for producing copolyamic acid are a sulfoxide solvent (e.g., dimethylsulfoxide or diethylsulfoxide), a formamide solvent (e.g., N,N-dimethylformamide or N,N-diethylformamide), an acetamide solvent (e.g., N,N-dimethylacetamide or N,N-diethylacetamide), a pyrrolidone solvent (e.g., N-methyl-2-pyrrolidone or N-vinyl-2-pyrrolidone), a phenol solvent (e.g., phenol, o-, m- or p-cresol, xylenol, halogenated phenol, or catechol), and an another organic polar solvent (e.g., hexamethylphosphorammide or Y-butyrolactone). These organic solvents are used singly or as a mixture. In addition, an aromatic hydrocarbon such as xylene or toluene may be added to the solvent. 5 to 40 wt%, preferably 5 to 30 wt%, and more preferably 5 to 25 wt% o the copolyamic acid are dissolved in the solvent when handling is also taken into consideration.
The reaction temperature falls within the range of 0 to 100° C., preferably 5 to 80° C., and more preferably 5 to 50° C.
When the amic acid prepolymer of the acid anhydride group terminal is used as an intermediate, the reaction temperature is preferably 30° C or less and more preferably 10° C or less. The reaction time falls within the range of 10 hours or less, preferably 5 hours or less, and more preferably 3 hours or less.
A polyimide can be derived from the resultant copolyamic acid, by use of one of the following two methods:
(i) Thermal dehydration and closing the ring (conversion into an imide)
(ii) Chemical dehydration and closing the ring (conversion into an imide).
According to method (i), a copolyamic acid solution is casted and dried on a support body such as a support plate, a heating drum, or an endless belt, thereby to obtain a self-supporting film. This film is gradually heated to a temperature of about 200 to 500° C, and preferably 300 to 500° C, to obtain a polyimide film.
According to method (ii), a dehydrate such as acetic anhydride and a tertiary amine such as pyridine, pycoline, or quinoline are added to a copolyamic acid solution. Thereafter, a polyimide film is formed following the same procedures as in method (i). When the self-supporting film is to be heated, it may be held on the support body or peeled off therefrom. In the latter case, if the edge of the film is fixed and the film is heated, a copolymer having a low linear thermal expansion coefficient can be obtained. When the method whereby the copolyamic acid is thermally converted into a polyimide is compared with that whereby the copolyamic acid is chemically converted, the chemical method is superior to the thermal method, from the viewpoints of mechanical properties and the linear thermal expansion coefficient.
The copolyimide of the present invention has good thermal dimensional stability as well as good mechanical properties. More specifically, the linear thermal expansion coefficient is 2.5×10 -5 or less, and an elongation is 20% or more.
In addition to its thermal dimensional stability and mechanical properties, the copolyimide of the present invention has a proper modulus. As a result, the copolyimide film can be used effectively as a film-like flexible printed circuit board, a magnetic recording material (especially perpendicular magnetic recording material) such as a magnetic type and a magnetic disk, and as a passivation film for ICs, LSIs, solar cells, and the like.
EXAMPLE 1
10.31 g of 4,4-diaminodiphenyl ether (to hereinafter be referred to as ODA) were charged in a 500-ml four neck flask, and 145.00 g of N,N-dimethylacetamide were added thereto to dissolve the ODA. Meanwhile, 16.90 g of pyromellitic dianhydride (to hereinafter be referred to as PMDA) were added to a 50-ml eggplant type flask and were added in solid form to the ODA solution. The PMDA attached to the inner wall surface of the 50-ml eggplant type flask was dissolved in 10.00 g of N,N-dimethylacetamide, this solution was poured into the reaction system (i.e., the four-neck flask), and the mixture was stirred for one hour, to thereby obtain an amic acid prepolymer of acid anhydride group terminals. 2.79 g of paraphenylene diamine (to hereinafter be referred to as a P-PDA) were charged in a 50-ml Erlenmeyer flask, and 15.00 g of N,N-dimethyleacetamide were added to dissolve the P-PDA. The resultant solution was added to the reaction system (i.e., the four-neck flask), whereby a copolyamic acid solution was obtained. In the above reactions, the reaction temperature was 5 to 10° C, with dry nitrogen gas being used to treat the PMDA was gas and to fill the reaction system.
The polyamic acid solution was casted and coated on a glass plate, was dried at about 100° C for about 60 minutes, after which the resultant polyamic acid film was peeled off the glass plate. Thereafter, the film was fixed in a frame and dried at about 100° C. for 30 minutes, at about 200° C for about 60 minutes, and at about 300° C, again for about 60 minutes. The film was dehydrated and subjected to ring closing, resulting in a polyimide film having a thickness of 15 to 25 μm.
The linear thermal expansion coefficient, the elongation break, and the modulus of the film are summarized in Table 1. Note that the linear thermal expansion coefficient was obtained at 200° C.
EXAMPLE 2
A copolyimide film was obtained following the same procedures as in Example 1, except that 8.07 g of the ODA, 17.58 g of the PMDA, and 4.35 g of the P-PDA were used. The properties of this film are summarized in Table 1.
EXAMPLE 3
4.35 g of P-PDA were charged in a 500-ml four neck flask, and 110.00 g of N,N-dimethylacetamide were added to dissolve the P-PDA. 17.58 g of the PMDA were charged in a 50-ml eggplant type flask and was added in solid form to the P-PDA. The PMDA attached to the inner wall surface of the 50-ml eggplant type flask was dissolved in 10.00 g of N,N-dimethylacetamide, and this solution was poured into the reaction system (i.e., the four neck flask). The resultant mixture was stirred for one hour, to obtain a amic acid prepolymer of acid anhydride group terminals. Meanwhile, 8.07 g of the ODA were charged in a 100-ml Erlenmeyer flask, and 50.00 g of N,N-dimethylacetamide were added thereto to dissolve the ODA. The resultant solution was added to the reaction system (i.e., the four-neck flask), whereby a copolyamic acid solution was obtained. In the above reactions, the reaction temperature was 5 to 10° C, with dry nitrogen gas being used to treat the PDMA and to fill the reaction system. A copolyimide film was obtained following the same procedures as in Example 1. The properties of this film are summarized in Table 1.
EXAMPLE 4
A copolyimide film was obtained following the same procedures as in Example 1, except that 12.02 g of the ODA, 16.36 g of the PMDA, and 1.62 g of the P-PDA were used. The properties of this film are summarized in Table 1.
EXAMPLE 5
A copolyimide film was obtained following the same procedures as in Example 3, except that 6.06 g of the P-PDA, 18.33 g of the PMDA, and 5.61 g of the ODA were used. The properties of this film are summarized in Table 1.
EXAMPLE 6
33.88 g of acetic anhydride and 5.32 g of pyridine were added to the polyamic acid solution obtained by use of the method of Example 2.
The polyamic acid solution composition was casted and coated on a glass plate, and dried at about 100° C. for approximately 10 minutes. The resultant self-supporting film was peeled off the plate and was fixed to a support frame. The film was then heated at about 200° C. for approximately 10 minutes, and at about 300° C. for approximately 20 minutes, resulting in a polyimide film having a thickness of 15 to 25 μm. The properties of this film are summarized in Table 1.
EXAMPLE 7
2.43 g of P-PDA were charged in a 500-ml four-neck flask, and 135.00 g of N,N-dimethyl acetamide were added thereto to dissolve the P-PDA. Meanwhile, 3.92 g of the PMDA were charged in a 100-ml eggplant type flask and added in solid form to the P-PDA solution. The resultant solution was stirred for one hour, to obtain an amic acid prepolymer of amino group terminals. 18.03 g of the ODA were charged in a 50-ml eggplant flask and were added in solid form to the amino group terminal amic acid prepolymer solution, and the solution was sufficiently stirred until the solid ODA was completely dissolved 20.62 g of the additional PMDA were charged in a 100-ml eggplant flask and were added in solid form to the reaction system (i.e., the four-neck flask). Subsequently, the solution was stirred for one hour, whereby a copolyamic acid solution was obtained. The reaction temperature was 5 to 10° C. In the reactions described above, dry nitrogen gas was used to treat the PMDA and to fill the reaction system.
A copolyimide film was prepared from the copolyamic acid solution, following the same procedures as in Example 1. The properties of this film are summarized in Table 1.
EXAMPLE 3
15.47 g of the ODA were charged in a 500-ml four-neck flask, and 255.00 g of N,N-dimethylacetamide were added thereto to dissolve the ODA. Meanwhile, 16.01 g of the PMDA were charged in a 100-ml eggplant flask and were added in solid form to the ODA solution. The solution was stirred for one hour, to obtain an amic acid prepolymer of amino group terminals. 4.19 g of the P-PDA were charged in a 50-ml eggplant flask and were added in solid form to the amino group terminal amic acid prepolymer solution. The solution was sufficiently stirred until the solid P-PDA was completely dissolved. 9.34 g of the additional PMDA were charged in a 100-ml eggplant flask and were added in solid form to the reaction system (i.e., the four-neck flask). The solution was stirred for one hour, whereby a copolyamic acid solution was obtained. The reaction temperature was kept at 5 to 10° C. In the above reactions, dry nitrogen gas was used to treat the PMDA and to fill the reaction system.
47.39 g of acetic anhydride and 9.17 g of pyridine were added to the resultant copolyamic acid solution, and the mixture thoroughly stirred. Following the same procedures as in Example 1, a copolyimide film was prepared from the copolyamic acid solution. The properties of this film are summarized in Table 1.
EXAMPLE 9
12.11 g of the ODA were charged in a 500-ml four-neck flask, and 255.00 g of N,N-dimethylacetamide were added to dissolve the ODA. Meanwhile, 11.88 g of the PMDA were charged in a 100-ml eggplant flask and were added in solid form to the ODA solution. The resultant solution was kept stirred for one hour, to obtain an amic acid prepolymer of amino group terminals. 6.53 g of the P-PDA were charged in a 50-ml eggplant type flask and were added in solid form to the amino group terminal amic acid prepolymer solution, and the resultant solution was sufficiently stirred until the added P-PDA was completely dissolved. 14.49 g of the additional PMDA were charged in a 100-ml eggplant type flask and were added in solid form to the reaction system (i.e., the four-neck flask). The resultant solution was kept stirred for one hour, whereby a copolyamic acid solution was obtained. The reaction temperature was kept at 5 to 10° C. In the above reactions, dry nitrogen gas was used to treat the PMDA and to fill the reaction system.
The resultant copolyamic acid mixture solution was flowed and coated on a glass plate, and dried at about 100° C. for 60 minutes. The copolyamic acid film was then peeled off the glass plate and fixed to a support frame. Thereafter, the film was heated at about 150° C. for approximately 30 minutes, and at about 300° C for 60 minutes, to perform dehydration and ring closing, whereby a copolyimide film having a thickness of 15 to 25 μm was obtained. The properties of this film are summarized in Table 1.
EXAMPLE 10
6.53 g of the P-PDA were charged in a 500-ml four-neck flask, and 255.00 g of N,N-dimethylacetamide were added to dissolve the P-PDA. Meanwhile, 11.86 g of the PMDA were charged in a 100-ml eggplant type flask and were added in solid form to the P-PDA solution. The resultant solution was kept stirred for one hour, to obtain an amic acid prepolymer of amino group terminals. 12.11 g of the ODA were charged in a 50-ml eggplant type flask and were added in solid form to the amino group terminal amic acid prepolymer solution, and the resultant solution was sufficiently stirred until the added ODA was completely dissolved. 14.51 g of the additional PMDA were charged in a 100-ml eggplant type flask and were added in solid form to the reaction system (i.e., the four-neck flask). The resultant solution was kept stirred for one hour, whereby a copolyamic acid solution was obtained. The reaction temperature was kept at 5 to 10° C. In the above reactions, dry nitrogen gas was used to treat the PMDA and to fill the reaction system.
The resultant copolyamic acid mixture solution was casted and coated on a glass plate, and dried at about 100° C. for 60 minutes. The copolyamic acid film was then peeled off the glass plate and fixed to a support frame. Thereafter the film was heated at about 150° C. for approximately 10 minutes, at about 200° C. for approximately 60 minutes, and at about 300° C. for 60 minutes, to perform dehydration and ring closing, whereby a copolyimide film having a thickness of 15 to 25 μm was obtained. The properties of this film are summarized in Table 1.
EXAMPLE 11
8.42 g of the ODA were charged in a 500-ml four-neck flask, and 255.00 g of N,N-dimethylacetamide were added thereto to dissolve the ODA. Meanwhile, 4.59 g of the PMDA were charged in a 100-ml eggplant type flask and were added in solid form to the ODA solution. The resultant solution was kept stirred for one hour, to obtain an amic acid prepolymer of amino group terminals. 9.09 g of P-PDA were charged in a 50-ml eggplant type flask and were added in solid form to the amino group terminal amic acid prepolymer solution, and the solution was sufficiently stirred until the added P-PDA was completely dissolved. 22.91 g of the additional PMDA were charged in a 100-ml eggplant type flask and were added to the above solution, and the resultant solution was kept stirred for one hour, whereby a copolyamic acid solution was obtained. The reaction temperature was kept at 5 to 10° C, and dry nitrogen gas was used to treat the PMDA and to fill the reaction system.
Following the same procedures as in Example 1, a copolyimide film wa prepared from the resultant copolyamic acid solution. The properties of this film are summarized in Table 1.
EXAMPLE 12
6.45 g of the ODA were charged in a 500-ml four-neck flask, and 255.00 g of N,N-dimethylacetamide were added thereto to dissolve the ODA. Meanwhile, 6.32 g of the PMDA were charged in a 100-ml eggplant type flask and were added in solid form to the ODA solution. The resultant solution was kept stirred for one hour, to obtain an amic acid prepolymer of amino group terminals. 10.44 g of P-PDA were charged in a 50-ml eggplant type flask and were added in solid form to the amino group terminal amic acid prepolymer solution, and the solution was sufficiently stirred until the added P-PDA was completely dissolved. 21.79 of the additional PMDA were charged in a 100-ml eggplant type flask and were added in solid form to the above reaction system (the four-neck flask), and the resultant solution was kept stirred for one hour, whereby a copolyamic acid solution was obtained. The reaction temperature was kept at 5 to 10° C, and dry nitrogen gas was used to treat the PDMA and to fill the reaction system.
Following the same procedures as in Example 1, a copolyimide film was prepared from the resultant copolyamic acid solution. The properties of this film are summarized in Table 1.
COMPARATIVE EXAMPLE 1
21.54 g of the ODA were charged in a 500-ml four-neck flask, and 245.00 g of N,N-dimethylacetamide were added thereto to dissolve the ODA. Meanwhile, 23.46 g of the PMDA were charged in a 100-ml eggplant type flask and were added in solid form to the ODA solution. The PMDA attached to the inner wall surface of this 100-ml eggplant type flask was dissolved in 10.00 g of N,N-dimethylacetamide, and this solution was poured into the reaction system (i.e., the four neck flask). The resultant solution was kept stirred for one hour, whereby a polyamic acid solution was obtained. The reaction temperature was kept at 5 to 10° C, and dry nitrogen gas was used to treat the PDMA and to fill the reaction system.
Following the same procedures as in Example 1, a polyimide film was prepared from the resultant polyamic acid solution. The properties of this film are summarized in Table 1.
COMPARATIVE EXAMPLE 2
4.35 g of the P-PDA and 8.07 g of the ODA were charged in a 500-ml four-neck flask, and 160.00 g of N,N-dimethylacetamide were added thereto to dissolve the P-PDA and the ODA. 17.58 g of the PMDA were reacted following the same procedures as in Comparative Example 1, whereby a copolyamic acid solution was produced by random copolymerization. The PMDA attached to the inner wall surface was dissolved in 10.00 g of N,N-dimethylacetamide, and the resultant solution was poured into the reaction system (i.e, the four neck flask).
Following the same procedures as in Comparative Example 1, a copolyimide film was prepared from the polyamic acid solution. The properties of this film are summarized in Table 1.
COMPARATIVE EXAMPLE 3
6.96 g of the P-PDA and 4.30 g of the ODA were charged in a 500-ml four-neck flask and 160.00 g of N,N-dimethylacetamide were added thereto to dissolve the P-PDA and the ODA. 18.73 g of the PMDA were caused to react with what following the same procedures as in Comparative Example 1, whereby a copolyamic acid solution was obtained by random copolymerization. The PMDA attached to the inner wall surface was dissolved in 10.00 g of N,N-dimethylacetamide, and the resultant solution was poured into the reaction system (i.e, the four neck flask).
Following the same procedures as in Comparative Example 1, a copolyimide film was prepared from the polyamic acid solution. The properties of this film are summarized in Table 1.
COMPARATIVE EXAMPLE 4
21.54 g of the ODA were charged in a 500-ml four-neck flask, and 2245.00 g of N,N-dimethylacetamide were added thereto to dissolve the ODA. Meanwhile, 23.46 g of the PMDA were charged in a 100-ml eggplant type flask and were added in the solid form to the ODA solution. The PMDA attached to the inner wall surface of this 100-ml eggplant type flask wa dissolved in 10.00 g of N,N-dimethylacetamide and the resultant solution was poured into the reaction system (i.e., the four neck flask). The solution was kept stirred for one hour, whereby polyamic acid solution (I) was obtained.
14.91 g of the P-PDA were charged in an another 500-ml four-neck flask, and 245.00 g of N,N-dimethylacetamide were added thereto to dissolve the P-PDA. 30.09 g of the PMDA were reacted following the same procedures as described above, whereby polyamic acid solution (II) was obtained. In all the above reactions, the reaction temperature was kept at 5 to 10° C, and dry nitrogen gas wa used to treat the PMDA and to fill the reaction system.
112.35 g of polyamic acid solution (I) were poured into an another 500-ml four-neck flask, and 87.65 g of polyamic acid solution (II) were added thereto and mixed. The mixture was kept stirred at 5 to 10° C. for about 10 minutes in the presence of dry nitrogen gas.
Following the same procedures as in Example 1, a polyimide film was prepared from the polyamic acid mixture solution. The properties of this film are summarized in Table 1.
TABLE 1__________________________________________________________________________ Amic Acid Prepolymer Diamine:A- Linear cid an- Expansion ODA:p-PDA hydride Coefficient Elongation (Molar Terminal (Molar (cm/cm/°C.) break ModulusExample Ratio) Group Diamine Ratio) (× 10.sup.-5) (%) kg/mm.sup.2__________________________________________________________________________Example 1 67:33 Acid Anhy- ODA 67:100 0.89 57.0 450 dride GroupExample 2 50:50 ↑ ODA 50:100 0.30 48.0 590Example 3 50:50 ↑ P-PDA 50:100 0.30 48.0 580Example 4 80:20 ↑ ODA 80:100 0.97 72.0 410Example 5 33:67 ↑ P-PDA 33:100 0.00 35.5 860Example 6 50:50 ↑ ODA 50:100 0.28 55.0 620Example 7 80:20 Amino P-PDA 100:80 1.87 68.8 380 GroupExample 8 67:33 ↑ ODA 100:95 0.37 40.5 410Example 9 50:50 ↑ ODA 100:90 0.60 50.0 570Example 10 50:50 ↑ P-PDA 100:90 0.11 33.8 560Example 11 33:67 ↑ ODA 100:50 -0.62 30.4 830Example 12 25:75 ↑ ODA 100:90 -2.55 21.1 950Comparative 100:0 -- -- -- 3.5 85.7 360Example 1Comparative 50:50 -- -- -- 0.9 20.0 550Example 2Comparative 25:75 -- -- -- 0.20 18.0 950Example 3Comparative 50:50 -- -- -- 0.69 14.7 520Example 4__________________________________________________________________________ | The present invention provides a copolyimide characterized in that the copolyimide contains units represented by formulas (I) and (II) ##STR1## (wherein R 0 represents an aromatic tetracarboxylic residue). The polyimide has excellent thermal dimensional stability, and can be fabricated by using conventional inexpensive materials. | 2 |
BACKGROUND
Recently increasing research efforts have been devoted to converting syn-gas (CO/CO 2 /H 2 ) to methanol and isobutanol mixtures for use as raw materials in methyltertiarybutylether synthesis (MTBE). Prior art catalysts consisted of modified methanol synthesis catalysts, such as mixtures of manganese, chromium, and (zinc) oxide promoted with alkali (Mn(Zn)O/Cr 2 O 3 /alkali) operated at high temperatures, and alkali promoted copper and zinc oxide (Cu/ZnO/alkali) operated at low temperatures. Keim et al., Catalysis Letters, 3, 59, 1989, describe a palladium supported on a coprecipitated manganese, zinc, zirconium, lithium oxide (ZrO 2 --ZnO--MnO--Li 2 O--Pd) catalyst which is highly active and selective for a one step synthesis of isobutanol. What is needed in the art is a catalyst capable of selectively producing methanol and isobutanol mixtures from syn-gas at lower temperatures (e.g. 290°-360° C. vs. 400° C.) and pressures (50 atm vs. 100-250 atm).
SUMMARY OF THE INVENTION
Applicants have discovered new catalysts based on coprecipitated mixtures or solid solutions of alkaline earth oxides and rare earth oxides, such as mixtures or solid solutions of magnesium oxide and cerium oxide, Mg 5 CeO x , or magnesium oxide and yttrium oxide, Mg 5 YO x , which catalyze aldol condensation reactions leading to the selective formation of branched C 4 alcohols. Applicants' catalysts may also contain a Group IB metallic component and further an alkali dopant. Preferably Cu in concentrations of 5 to 30 wt % inclusive, and K in concentrations of 0.5 to 3 wt % inclusive will be used. Applicants' catalysts afford the advantage of being run at pressures lower than those required by Keim catalysts and are more active and selective to methanol and isobutanol.
The present invention is directed to catalyst compositions comprising a coprecipitated mixture or a solid solution of a rare earth oxide and a Group IIA oxide.
The catalyst composition may further comprise a Group IB metal and may still further comprise an alkali dopant.
The invention is also directed to the use of the catalysts in a syn-gas conversion reaction.
DETAILED DESCRIPTION OF THE INVENTION
The catalysts of the present invention are prepared by coprecipitation of rare earth oxides and alkaline earth oxides at controlled pH. Preferably the Group IB metal will also be coprecipitated. For example copper oxide can be coprecipitated and then reduced to Cu prior to catalyst use. During the preparation of the instant catalysts, the pH will be controlled between 9-11. The catalysts are easily prepared by techniques known to those skilled in the art. The catalyst components are solutions of soluble salts, e.g. Ce(NO 3 ) 3 .6H 2 O and Mg(NO 3 ).6H 2 O or any other soluble salts. The solution containing the soluble salt is then mixed with a basic solution e.g. KOH to cause precipitation. This mixing of the soluble salt solution and base is performed at a pH of between 9-11. A coprecipitated solid is thus obtained. The Group IIA component may be present as a carbonate, hydroxide, or mixture of the two at this stage in the catalyst preparation depending on whether a hydroxide or carbonate solution was used as the basic solution, and whether any CO 2 was absorbed from the atmosphere. The catalysts are then calcined at about 350°-1000° C. to convert the Group IIA and rare earth salts into their respective oxides. The calcination temperature will depend on the particular rare earth and Group IIA salts and is readily determined by one skilled in the art. Preferably the additional Group IB metal which may also form part of the present catalyst will be simultaneously contained in the soluble salt solution and coprecipitated. When the molar ratio of rare earth oxide to Group IIA oxide is greater than about 50-80%, a solid solution forms wherein the Group IIA oxide is substituted into the rare earth oxide. For example, an atomic ratio of 5 IIA /1 rare earth would yield a coprecipitated mixture and 0.5 IIA /1 rare earth a solid solution. These can be easily distinguished by verifying the presence of two or one phases in the x-ray diffractogram.
Any soluble salts of the rare earths and Group IIA elements can be used to form the solutions of soluble salts for coprecipitation. For example, nitrates, acetates, halides etc. can be used, or any other salts known to those skilled in the art to form the desired product.
The catalysts of the present invention will typically comprise from about 10 to about 70 wt % of the Group IIA oxide, preferably 10 to about 30 wt %. Such Group IIA oxide can be selected from any of the Group IIA oxides of Mg, Ca, Sr, Ba, and mixtures thereof. Preferably magnesium oxide will be used.
The rare earth oxide will be present in an amount ranging from about 40 to about 90 wt %, preferably about 70 to about 90 wt %. The rare earth oxides are the oxides of the elements of the periodic table having atomic numbers 57 to 71 inclusive. Also included is yttrium, having an atomic number of 39, which behaves similar to rare earths in many applications. Preferably ceria or yttria will be used. Mixtures of the rare earth oxides may also be used.
When the catalyst composition of the present invention further comprises a metal, the metal will be selected from the Group IB elements and mixtures thereof. Preferably Cu will be used. The amount of metal will range from about 5 to 30 wt %, preferably about 5 to about 20 wt %, most preferably less than 10 wt %. Preferably, the metal will be Cu.
When the catalyst composition further comprises an alkali dopant, such dopant will be selected from the elements of Group IA of the periodic table (Kirk-Othmer, Encyclopedia of Chemical Technology, 2nd ed., 1965, pg 94), Li, Na, and K. Preferably potassium will be used. The alkali dopant will be present in an amount ranging from about 0.5 to about 3 wt %, preferably about 0.5 to about 1.5 wt %, and most preferably less than 1 wt %. As used herein, alkali dopant means a Group IA alkaline element added to the catalyst.
The catalysts of the present invention are particularly useful for converting synthesis gas to oxygenates, especially methanol and isobutanol. Isobutanol is a key intermediate reactant for the synthesis of methyltertiarybutylether (MTBE). MTBE has become increasingly important for use in low emissions gasoline.
The catalysts of the present invention convert synthesis gas (syn-gas), which comprises carbon monoxide, carbon dioxide and hydrogen, into oxygenates. Predominantly methanol and isobutanol are formed, while some other linear alcohols, branched alcohols, dimethylether, and esters are also formed as by-products.
A typical conversion of syn-gas is conducted at temperatures ranging from about 260° to about 420° C., pressures of 50 to about 250 atm, and GHSV 1000 to 5000 CC(STP)/g cat. hr. The H 2 :CO molar ratio ranges from about 2 to about 0.5, preferably an H 2 :CO ratio of 1 will be used. The present invention catalyst is advantageous because it can also selectively produce isobutanol and methanol at lower pressures of 20-50 atmospheres in addition to pressures of 50 to about 250 atmospheres. The present invention catalyst will preferably be run at pressures of 20-50 atmospheres with other conditions being those of a typical syn-gas conversion reaction.
The syn-gas conversion to alcohols can be represented by the reactions
2nH.sub.2 +nCO→C.sub.n H.sub.2n+1 OH+(n-1)H.sub.2 O
(n+1)H.sub.2 +(2n-1)CO→C.sub.n H.sub.2n+1 OH+(n-1)CO.sub.2
specifically, isobutanol production is represented by the reactions
8H.sub.2 +4CO→C.sub.4 H.sub.9 OH+3H.sub.2 O
5H.sub.2 +7CO→C.sub.4 H.sub.9 OH+3CO.sub.2
The catalysts of the present invention can be used for selectively producing methanol and isobutanol mixtures from syn-gas at lower temperatures and pressures (e.g. 290° C.-360° C. vs 400° C. and 20-250 atms vs. 100-250 atm, respectively). The higher temperature and pressures are what is typically required for prior art catalysts.
The following examples are illustrative of the invention but not limiting.
EXAMPLE 1
Several catalysts were prepared, including Keim type catalyst for comparison with the catalysts of the instant invention. The supported catalysts are designated by a slash, e.g., Cu/M.sub.α M.sub.β 'O x designates a supported copper catalyst where Cu is in wt % and α and β are gm atom quantities. Coprecipitated catalysts are designated without a slash, e.g., Cu z M.sub.α M.sub.β βO x where z, α, and β are gm atom quantities. Note that the rare earth and Group IIA oxides designated by M" and M are always coprecipitated and the slash or absence thereof indicates whether the alkali dopant or Group IB metal is supported or the Group IB is coprecipitated. x is easily calculated by one skilled in the art by multiplying the valence of each cation by the number of gm atoms and dividing by (the valence of oxygen=2), e.g. Cu. 5 Mg 5 CeO x with Cu +2 , Mg +2 , Ce +4 , x=(1+10+4)/2=7.5.
7% Cu/CeO 2 (7% copper supported on ceria)
41 gm of Ce(NO 3 ) 3 .6H 2 O was dissolved in 200 cc H 2 O. 35 cc of 14.8 molar NH 4 OH was dissolved in 200 cc of H 2 O and added to the cerium nitrate solution until the pH reached 9.5. The precipitate is filtered, washed with water and dried at 100° C. overnight. The material is then calcined at 500° C. overnight to convert to CeO 2 . 2.7 gms of Cu(NO 3 ) 2 .H 2 O was dissolved in 3 cc of H 2 O and impregnated onto 10 grams of the CeO 2 , which was then dried overnight at 110° C. and calcined at 450° C. for four hours.
Cu. 5 Mg 5 CeO x (coprecipitated copper, magnesium oxide, and ceria)
A one liter aqueous solution (A) containing 197.4 gm of Mg(NO 3 ) 2 .6H 2 O, 66.9 gm of Ce(NO 3 ) 3 .6H 2 O and 18.4 gm of Cu(NO 3 ) 2 .3H 2 O was prepared. A second one liter aqueous solution (B) containing 120.8 gm of KOH and 10.8 gm of K 2 CO 3 was also prepared. The two solutions were added to 400 cc of water kept at 65°-70° C. contained in a 4 liter beaker. 15 cc/min of solution A was added by a pump into the 4 liter beaker. The simultaneous addition of solution (B) was controlled so that the pH of the well stirred mixture was maintained at 9. After solution (A) was exhausted, the resulting precipitate was filtered, washed with hot water and dried at 80° C. overnight. The catalyst was then calcined at 450° C. for four hours.
0.9% K/Cu. 5 Mg 5 CeO x (potassium supported on coprecipitated copper, magnesium oxide, and ceria)
9.91 grams of the calcined catalyst above was taken. 0.16 gm of K 2 CO 3 was dissolved in 8 cc of water and impregnated by incipient wetness. The catalyst was then calcined at 450° C. for four hours.
0.25% Pd/ZrZnMnO x (Keim type)
A one liter aqueous solution (A) containing 202.4 gm of ZrO(NO 3 ) 2 .4H 2 O, 198.4 gm of Zn(NO 3 ) 2 .6H 2 O and 238.6 gm of a 50% aqueous solution of manganese nitrate was prepared. A second one liter aqueous solution (B) containing 168.0 gm of lithium hydroxide was also prepared. The two solutions were added to 400 cc of water kept at 65°-70° C. contained in a 4 liter beaker. 15 cc/min of solution (A) was added by a pump into the 4 liter beaker. The simultaneous addition of solution (B) was controlled so that the pH of the well stirred mixture was maintained at 11. After solution (A) was exhausted, the resulting precipitate was filtered, washed with hot water and dried at 120° C. overnight.
100 gm of the washed and 120° C. dried precipitate preparation above was taken. 5 cc of a palladium solution (0.05 gm Pd/cc) was added to 20 cc of water and impregnated to the point of incipient wetness, dried at 110° C., and then calcined at 330° C. for 3 hours. All catalysts were reduced in 100% H 2 for four hours at 260° C. before use.
7% Cu/Mg 5 YO x copper supported on magnesium oxide, and yttria
A one liter aqueous solution (A) containing 106.9 gm of Mg(NO 3 ) 2 .6H 2 O, and 31.8 gm of Y(NO 3 ) 3 .6H 2 O was prepared. A second one liter aqueous solution (B) containing 60.8 gm of KOH and 5.8 gm of K 2 CO 3 was also prepared. The two solutions were added to 600 cc of water kept at 65°-70° C. contained in a 4 liter beaker. 15 cc/min of solution A was added by pump into the 4 liter beaker. The simultaneous addition of solution (B) was controlled so that the pH of the well stirred mixture was maintained at 9. After solution (A) was exhausted, the resulting precipitate was filtered, washed with hot water and dried at 80° C. overnight. The catalyst was then calcined at 450° C. for four hours.
2.7 gm of Cu(NO 3 ) 2 .3H 2 O was dissolved in 3 cc of H 2 O and impregnated onto 10 gm of the Mg 5 YO x by incipient wetness, and then dried at 110° C. and calcined at 450° C. for 4 hours.
Cu. 45 YCeMgO x coprecipitated copper, yttria, ceria, and magnesium oxide
A one liter aqueous solution (A) containing 37.2 gm of Mg(NO 3 ) 2 .6H 2 O, 15.7 gm of Cu(NO 3 ) 2 .3H 2 O, 63.0 gm of Ce(NO 3 ) 3 .6H 2 O, and 55.5 gm of Y(NO 3 ) 3 .6H 2 O was prepared. A second one liter aqueous solution (B) containing 72.4 gm of KOH and 20.0 gm of K 2 CO 3 was also prepared. The two solutions were added to 600 cc of water kept at 65°-70° C. contained in a 4 liter beaker. 15 cc/min of solution (A) was added by a pump into the 4 liter beaker. The simultaneous addition of solution (B) was controlled so that the pH of the well stirred mixture was maintained at 9. After solution (A) was exhausted, the resulting precipitate was filtered, washed with hot water and dried at 80° C. overnight. The catalyst was then calcined at 450° C. for four hours.
Cu. 45 NdCeMgO x coprecipitated copper, neodymium oxide, ceria and magnesium oxide
A one liter aqueous solution (A) containing 37.2 gm of Mg(NO 3 ) 2 .6H 2 O, 15.7 gm of Cu(NO 3 ) 2 .3H 2 O, 63.90 gm of Ce(NO 3 ) 3 .6H 2 O, and 60.9 gm of Nd(NO 3 ) 3 .5H 2 O was prepared. A second one liter aqueous solution (B) containing 72.4 gm of KOH and 20.0 gm of K 2 CO 3 was also prepared. The two solutions were added to 600 cc of water kept at 65°-70° C. contained in a 4 liter beaker. 15 cc/min of solution (A) was added by a pump into the 4 liter beaker. The simultaneous addition of solution (B) was controlled so that the pH of the well stirred mixture was maintained at 9. After solution (A) was exhausted, the resulting precipitate was filtered, washed with hot water and dried at 80° C. overnight. The catalyst was then calcined at 450° C. for four hours.
Catalyst Reaction Testing
Three grams of catalyst sized to 30/60 mesh was mixed with a quantity of quartz chips (30-60 mesh) diluent such that the total catalyst volume equals 18 cc. This charge was loaded into a fixed bed reactor of 0.37" inner diameter. All catalysts were reduced under 100% H 2 by raising the reactor temperature at 0.5 deg/min to 260° C. and holding at that temperature for 4 hours. The reactor was then depressurized and the 1:1H 2 /CO feed was introduced at 245° C. at atmospheric pressure. The pressure was raised to 50 atmospheres, the space velocity and temperatures adjusted to the values indicated in the examples, and the products monitored by on-line gas chromatography. The data indicated in the tables was measured 70-110 hours into the run.
Table 1 shows high CH 3 OH and isobutanol productivity for catalysts of the present invention.
TABLE 1__________________________________________________________________________ 0.9% K/ 7% Cu/Mg.sub.5 YO.sub.x Cu.sub..5 Mg.sub.5 CeO.sub.x Cu.sub..5 Mg.sub.5 CeO.sub.x Cu.sub..5 Mg.sub.5 CeO.sub.x Cu.sub..45 YCeMgO.sub.x Cu.sub..45 NdCeMgO.s ub.x (320° C.) (290° C.) (320° C.) (320° C.) (290° C.) (290° C.) Sel Prod Sel Prod Sel Prod Sel Prod Sel Prod Sel ProdPRODUCT (% C) (g/kg/h) (% C) (g/kg/h) (% C) (g/kg/h) (% C) (g/kg/h) (% C) (g/kg/h) (% (g/kg/h)__________________________________________________________________________Methanol 42.53 60.76 70.72 147.55 48.41 63.98 57.19 66.82 83.15 128.80 82.57 144.52Ethanol 2.83 2.90 1.48 2.22 0.81 0.77 1.87 1.45 1.09 1.21 0.51 0.641-Propanol 2.59 2.32 2.02 2.63 1.24 1.02 2.64 1.84 1.32 1.28 0.65 0.711-Butanol 0.38 0.32 0.17 0.21 0.10 0.07 0.28 0.17 0.15 0.13 0.10 0.11Isobutanol 5.26 4.35 8.22 9.92 9.25 7.07 10.44 7.16 5.92 5.30 8.16 8.261-Pentanol 0.22 0.17 0.20 0.23 0.45 0.33 0.68 0.31 0.19 0.16 0.28 0.272m-1-butanol 0.08 0.54 0.98 1.12 0.58 0.42 1.17 0.71 0.60 0.51 0.76 0.74Hexanol 0.19 0.26 0.09 0.10 0.26 0.18 0.19 0.11 0.10 0.08 0.06 0.06DME 1.31 0.41 3.35 5.02 2.97 2.82 1.16 1.04 0.40 0.45 1.64 2.07Methane 18.62 13.30 8.38 8.7 20.06 13.19 11.52 6.78 3.26 2.52 3.70 3.24Higher-Hyd 23.68 -- 4.16 -- 15.49 -- 12.79 -- 3.10 -- 2.71 --CO.sub.2 (% C) 32.17 -- 22.53 -- 40.43 -- 31.04 15.41 -- 17.08 --Alc/Hyd (% C) 1.31 6.73 1.73 2.94 14.55 14.58CO Conv (%) 19.9 25.5 21.02 15.5 17.6 20.6GHSV (cc/ 1832 1832 1832 1832 1832 1832g cat.h)__________________________________________________________________________ (H.sub.2 : CO = 1 P = 50 atm) Selectivities in % C CO.sub.2 Free basis
EXAMPLE 2
A comparison between 0.9% K/Cu. 5 Mg 5 CeO x and 0.25% Pd/ZrZnMnO x Keim's-type catalyst was performed at 290° C., 320° C., and 360° C. and is tabulated in Table 2 below. The catalysts compared are the same catalysts as described in Example 1 (for which data is presented in Table 1, exclusive of the Keim catalyst).
TABLE 2__________________________________________________________________________Comparison Between 0.9% K/Cu.sub..5 Mg.sub.5 CeO.sub.xAnd 0.25% Pd/ZrZnMnO.sub.x Keim's-type Catalyst Productivity (g/kg cat/h) 0.9% K/Cu.sub.5 Mg.sub.5 CeO.sub.x 0.25% Pd/ZrZnMnO.sub.xProduct (290° C.) (320° C.) (360° C.) (290° C.) (320° C.) (360° C.)__________________________________________________________________________Methanol 144.5 66.8 30.7 21.2 40.2 20.5Isobutanol 5.7 7.2 7.5 0.3 1.1 3.5Total Alcohols 154.9 79.6 39.2 21.7 41.7 27.0Alcohols/Hydroc 11.14 2.94 0.66 6.06 3.32 0.71CO Conv (%) 19.9 15.5 19.0 2.8 6.9 10.8__________________________________________________________________________ Selectivities in % C; CO.sub.2free basis H2/CO = 1; P = 50 atm; GHSV = 1832 cc(STP)/[(g cat) · h
This example shows that K-promoted coprecipitated copper, magnesium and cerium oxides provide higher productivity and better selectivity to isobutanol than Keim's catalysts when compared at low pressure (50 atmospheres and varying temperatures (290°-360° C.)) conditions.
EXAMPLE 3
The Cu. 5 Mg 5 CeO x catalyst of Example 1 was tested at five different temperatures and the results are tabulated in Table 3. Increasing temperatures increases the isobutanol formation rate while methanol yield decreases due to thermodynamic equilibrium constraints. Thus, the isobutanol to methanol ratio increases at higher temperatures. However, the production of CO 2 , methane, and higher hydrocarbons also increase at higher temperatures.
TABLE 3______________________________________Catalyst: Cu.sub..5 Mg.sub.5 CeO.sub.xSelectivities in % C (CO.sub.2 -free basis)P = 50 atm; GHSV = 1832 cc/g cat · h; H.sub.2 :CO = 1Temp(°C.) CH.sub.3 OH Isobutanol LALC CH4 C.sub.2 (+)______________________________________260 89.0 2.6 3.2 2.6 0.01275 81.7 5.0 3.9 4.6 0.9290 70.6 8.2 4.1 8.4 4.1320 50.2 9.6 3.0 18 14360 23.6 9.8 2.3 26 31______________________________________ C.sub.2 (+): All hydrocarbons except methane LALC: C.sub.2 to C.sub.6 linear alcohols
EXAMPLE 4
The 0.9% K/Cu. 5 Mg 5 CeO x catalyst of Example 1 was tested at several different space velocities.
Table 4 shows the effect of contact time. Long contact times favored isobutanol and branched alcohols production (terminal products) while decreasing methanol slightly (primary product); linear alcohols (ethanol, propanol, and butanol) did not change appreciably (intermediate products). Hence, selectivities can be somewhat controlled by the temperature and space velocity of the reaction.
TABLE 4______________________________________Catalyst: 0.9% K/Cu.sub..5 Mg.sub.5 CeO.sub.xAlcohol Fraction, Selectivities in % CT = 290° C.; P = 50 atm; H.sub.2 :CO = 1GHSV Iso- Eth- Pro- Bu- 2 ml(cc/g · h) CH.sub.3 OH butanol anol panol tanol Butanol______________________________________1850 89.0 5.8 1.7 2.2 0.1 0.7920 85.8 8.5 1.6 2.3 0.2 1.0460 81.7 12.1 1.5 2.3 0.2 1.3______________________________________
EXAMPLE 5
Effect of the Support in Cu-containing catalysts
Three catalysts were prepared, as detailed in Example 1, to determine the effect of the support in Cu-containing catalysts.
Catalyst A: 7% Cu/CeO 2
Catalyst B: Cu. 5 Mg 5 CeO x
Catalyst C: 0.9% K/Cu. 5 Mg 5 CeO x
TABLE 5______________________________________Oxygenate fraction. Selectivities (in % C) 290° C. 320° C.Oxygenates A B C A B C______________________________________Methanol 84.38 79.05 87.3 69.2 74.2 74.6Ethanol 7.24 1.66 1.71 7.40 1.23 2.40Propanol 3.23 2.25 2.13 6.14 1.90 3.39Butanol 0.50 0.19 0.11 0.86 0.15 0.35Isobutanol 2.30 9.19 5.69 10.24 14.17 13.402-m-1-butanol 0.40 1.08 0.73 1.94 0.90 1.51Others 1.95 6.64 2.33 4.19 7.47 3.18Total alcohols 99.2 164.6 162.2 75.01 76.01 77.92productivityIsobutanol 1.50 9.92 5.68 5.14 7.07 7.16productivityBranched/Linear 1.50 2.56 1.73 0.85 3.69 2.18alcohols ratioCO conv (%) 12.8 25.5 20.4 16.4 21.02 15.5Alc/Hyd (% C) 8.5 6.03 15.2 2.61 1.63 2.94______________________________________ Productivities, in g/kg cat/h P = 50 atm; H.sub.2 /CO = 1: T = 320° C.; GHSV = 1832 cc(STP)/[(g cat) · h
Example 5 illustrates the effect of the support on Cu-containing catalysts. At 290° C., Cu supported on CeO 2 produced a low selectivity to isobutanol and the major products in the oxygenate fraction other than methanol were ethanol and propanol. At 320° C. the selectivity to isobutanol increased to 10.2% but the production of linear alcohols was still significant giving a branched/linear alcohols ratio of 0.85. When copper oxide was coprecipitated with magnesia and ceria and then reduced, as in Cu. 5 Mg 5 CeO x , the activity, selectivity, and productivity to isobutanol increased dramatically. Compared with the 7% Cu/CeO 2 catalyst at 290° C., CO conversion increased from 12.8 to 25.5%, isobutanol selectivity from 2.3 to 9.19% and isobutanol productivity from 1.50 to 9.92 g/kg cat/h. At 320° C., Cu. 5 Mg 5 CeO x remained more active and selective to isobutanol than 7% Cu/CeO 2 . The gain in isobutanol productivity was accompanied by a simultaneous diminution of the formation of linear alcohols and, as a consequence, the branched/linear alcohols ratio increased from 0.85 (Catalyst A) to 3.69 (Catalyst B). Adding K to Catalyst B produced a less active catalyst; however, the presence of an alkali dopant diminished the formation of hydrocarbons and dimethylether. For example, the alcohol/hydrocarbon ratio increased from 1.63 (Catalyst B) to 2.94 (Catalyst C) at 320° C. Finally, at 320° C. the 0.9% K/Cu. 5 Mg 5 CeO x catalyst gives similar isobutanol yield compared to the undoped catalyst and higher selectivity to alcohol formation. | Applicants have discovered new catalysts based on coprecipitated mixtures or solid solutions of alkaline earth oxides and rare earth oxides, such as mixtures or solid solutions of magnesium oxide and cerium oxide, Mg 5 CeO x , or magnesium oxide and yttrium oxide, Mg 5 YO x , which catalyze aldol condensation reactions leading to the selective formation of branched C 4 alcohols. Applicants' catalysts may also contain a Group IB metallic component and further an alkali dopant. Preferably Cu in concentrations at or lower than 30 wt % and K in concentrations at or lower than 3 wt % will be used. Applicants' catalysts afford the advantage of being run at pressures lower than those required by prior art catalysts and are more active and selective to methanol and isobutanol. | 8 |
The present invention relates to the construction and arrangement of a selectively controlled valve assembly through which fluent matter such as corrosive fluids and solid waste slurries is conducted.
BACKGROUND OF THE INVENTION
Diverter valves through which corrosive fluent materials are conducted have been traditionally constructed with components made of cast bronze or other expensive corrosion resistant metal alloys, and also incorporate components made of fiber-reinforced thermoplastics such as Teflon to provide sealing surfaces. Such valves have nevertheless exhibited numerous operational problems such as poor fire performance due to melting of valve seats, as well as scaling and galvanic corrosion, and melting of protective coatings due to thermal conductivity of a metallic valve housing. It is therefore an important object of the present invention to provide a diverter valve assembly of the foregoing type which is capable of more effectively handling corrosive fluids and solid waste slurries while safely reacting to conduit shock loads typically experienced in marine vessel installations.
SUMMARY OF THE INVENTION
In accordance with the present invention, a ball shaped flow controlling element of a diverter valve assembly is angularly displaced about the axis of a valve actuating shaft extending through a closure end plate into a metallic valve housing within which a tube is positioned to enclose the ball shaped element and cavities on opposite sides thereof. Such cavities are minimized in size by being occupied with thermoplastic fillers. One axial end portion of the tube is sealed by O-rings to the housing and by a gasket to the end plate through which the valve actuating shaft extends into one of the cavities for torsional coupling to the ball element. The other axial end portion of the tube and the housing are also sealed by an O-ring and gasket on the other closure end plate to prevent leakage during flow of various fluent materials through the ball element, including seawater, sewage and oily waste fluids. The foregoing components of the valve assembly exposed to fluent material within the housing are made of corrosion resistant material such as a thermosetting resin composite that is fiber reinforced so as to withstand shock loading.
Inserts having flange portions seated within openings in the housing, threadedly project by an adjusted amount through the tube into seated engagement with the ball element. Spring-like pressure so exerted on the ball element is adjustable during threaded installation of the inserts so as to optimize sealing and operational torque applied to the ball element through the valve actuating shaft for angular displacement thereof between flow blocking and flow directing positions. At least one of the inserts may be of a flow blocking plug type for certain installations while the other inserts are provided with flow through port passages. O-ring seals carried by the inserts engage the housing and the ball element to prevent leakage.
BRIEF DESCRIPTION OF THE DRAWINGS
A more complete appreciation of the invention and many of its attendant advantages will be readily appreciated as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawing wherein:
FIG. 1 is a perspective view of a valve assembly constructed in accordance with one embodiment of the present invention;
FIG. 2 is a front elevational view of the valve assembly shown in FIG. 1;
FIG. 3 is a side section view taken substantially through a plane indicated by section line 3--3 in FIG. 2;
FIG. 4 is a partial section view taken substantially through a plane indicated by section line 4--4 in FIG. 3;
FIG. 5 is an enlarged partial section view taken substantially through a plane indicated by section line 5--5 in FIG. 3;
FIG. 6 is a section view taken substantially through a plane indicated by section line 6--6 in FIG. 3;
FIG. 7 is a perspective view of the ball valve element associated with the valve assembly illustrated in FIGS. 1-6;
FIG. 8 is a section view of the ball valve element taken substantially through a plane indicated by section line 8--8 in FIG. 7; and
FIGS. 8A and 8B are section views similar to that of FIG. 8, respectively illustrating different embodiments of a ball valve element capable of being utilized in the valve assembly of FIGS. 1-8 in place of the ball valve element shown in FIGS. 7 and 8.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
Referring now to the drawing in detail, FIGS. 1 and 2 illustrate a diverter valve assembly generally referred to by reference numeral 10, constructed in accordance with one embodiment of the present invention. The valve assembly 10 embodies a generally cubic shaped framework housing 12 having four generally square-faced side walls 14 interconnected at right angles to each other by bevel corner sections 16. Such side walls 14 extend between top and bottom rectangular closure end plates 18 and 20 secured to the housing end walls by a plurality of screw fasteners 22. A valve actuating stem or shaft 24 extends into the housing 12 through the top end plate 18 and a circular gland plate element 26 secured to the housing by a pair of screws fasteners 28. The end plates 18 and 20 are respectively spaced from direct contact with the top and bottom ends of the side walls 14 by face gaskets 30 and 32 to seal the interior of the housing 12.
The foregoing described framework housing 12 is typically made of cast bronze or copper-alloy metal. The side walls 14 of such housing 12 are furthermore provided with drilled holes 34 for attachment thereto of flow conduits or pipes having flanges with fasteners that mate with the holes 34. The valve actuating shaft 24 extending from the top end of the housing 12 has a shear-pin hole 36 formed therein so that it may be attached to a suitable handle through which valve displacing motion about an axis 38 may be imparted thereto.
With continued reference to FIG. 1, each of the four side walls 14 of the framework housing 12 is provided with a circular opening 40 adapted to receive one of two types of inserts 42 and 44. Such inserts as well as the top and bottom end plates 18 and 20 are made of a fiber-reinforced, thermosetting resin composite material. The insert 42 is of a solid plug type while the insert 44 has a full-through bore to form a flow port passage. By selection of the type of insert utilized for each side wall 14, the valve assembly 10 may be configured for different multi-port valve operations in response to angular displacement of the valve actuating shaft 24, including 2-way or 3-way operation, or 4-way operation in which case no solid plug type insert 42 is utilized.
Referring now to FIGS. 3, 4, 5 and 8 in particular, a multi-port type of flow controlling component in the form of a ball shaped element 46 made of a fiber-reinforced thermosetting resin composite material is shown positioned within the housing 12 for angular displacement by the valve actuating shaft 24 about its rotational axis 38. The ball element 46 has a cross-sectionally square recess 48 formed therein for reception of a torsion transmitting coupling 50 extending axially from a flange portion 52 at the lower end of the valve actuating shaft 24 within the housing 12. The ball element 46 is furthermore disposed in spaced relation to both the top and bottom end plates 18 and 20 within a thick-walled cylindrical tube 54 also made of fiber-reinforced thermosetting resin composite material. Such tube 54 extends in coaxial spaced relation to the stem 24 to enclose the ball valve element 46 between the end plates 18 and 20. Such ball element 46 is provided with a pair of parallel spaced planar faces 56, at right angles to another pair of parallel spaced planar faces 58 and 60. As more clearly seen in FIGS. 7 and 8, a flow passage 62 extends completely through the ball element 46 between the parallel spaced valve faces 56 in communication with a flow passage 64 at right angles thereto extending from the valve face 60. In the embodiment illustrated in FIGS. 1-8, no flow passage extends from the valve face 58 so as to block flow through those side walls 14 within which the inserts 42 are positioned.
As shown in FIGS. 2 and 3, the face gasket 30 underlies the top end plate 18, secured to the upper ends of the side walls 14 by the fasteners 22. Such gasket 30 is in surrounding relation to a central axially projecting portion 66 of the top end plate 18 to form an annular receiving formation for the end walls 14 and tube 54 in contact with the face gasket 30. Also, there is an O-ring seal 68 embedded in the projecting portion 66 of the top end plate 18 spaced from the ball element 46 to seal a cavity occupied by a filler 70 made of a thermoplastic such as Teflon. The filler 70 has an opening through which projection 50 extends from flanger 52 on the lower end of shaft 24 on which a thrust washer 72 is received to seat the flange 52 within an annular recess in the projecting portion 66 of the top end plate 18. The valve actuating shaft 24 is also protectively enclosed within the axial bore formed in the top end plate 18 in close spaced relation to the thrust washer 72, by a Teflon padding gland 74 in axial abutment with an axially extending portion of the gland plate 26 made of a corrosion resistant metal. A cavity is also enclosed at the lower end of the valve assembly occupied by a thermoplastic filler 78 between the ball element 46 and a central axially projecting portion 67 of the bottom end plate 20 forming an annular space on the end plate receiving the end walls 14 and the tube 54 seated on an annular gasket 32. An O-ring seal 80 is embedded in the projecting portion 67 of the bottom end plate 20 for engagement with the tube 54 to seal the cavity occupied by the filler 78.
The tube 54 is formed with four internally threaded openings 82 intermediate its opposite axial ends in respective alignment with the openings 40 in the side walls 14 of the housing so as to threadedly receive the inserts 42 and 44 therein by an adjusted amount during assembly and/or installation. Such inserts embed annular O-ring seals 84 on flange portions 45 for contact with the side walls 14 within the openings 40 therein as shown in FIGS. 3 and 5 so as to prevent leakage from the tube 54. Each valve seat 88 on the ball element 46 embeds an O-ring seal 86 on its back face in contact with an inert 42 or 44, which spring loads the seat 88 against the ball element 46 so as to aid in providing a positive seal therewith.
The foregoing described arrangement for the valve assembly 10 features certain interrelationships between the tube 54 and end plates 18 and 20 which improve valve performance through ball element 46 with enhanced maintenance free operation despite the corrosion and erosion effects of fluids and fluent materials being handled. In addition to accommodating the described ball element 46, wherein a T-bore arrangement of flow passages 62 and 64 opening at three of the four valve faces 56 and 60 as shown in FIG. 8 may be selectively aligned with port openings 40 in the housing side walls 44 through port passages 90 in the inserts 44 as shown in FIG. 5 by angular valve displacement about axis 38, FIGS. 8A and 8B illustrate by way of example other forms of ball type elements 46' and 46" which may be accommodated within the diverter valve assembly 10 as replacements for the ball element 46 hereinbefore described. As shown in FIG. 8A, a ball element 46' has an internal L-bore flow passage 92 extending between openings formed in only two of the planar valve faces 56' and 60' at right angles to each other. As shown in FIG. 8B, a single straight-bore flow passage 62' is formed in the ball element 46" extending between openings formed on only two of the planar valve faces 56" parallel to each other.
Obviously, other modifications and variations of the present invention may be possible in light of the foregoing 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. | The metallic housing of a diverter valve assembly has a plurality of thredly positioned inserts therein through which different port passage paths are established with a multi-ported ball valve element angularly displaceable inside the housing while sealingly enclosed within a tube through which the inserts project into adjusted seating engagement with the ball valve element. | 5 |
BACKGROUND OF INVENTION
This invention relates to improvements in a composite wood beam assembly which is used as a joist to support, for example, building roof structures and the like. An example of such a composite wood beam is disclosed in my U.S. Pat. No. 4,501,102 issued Feb. 26, 1985. In that patent, the described beam is formed of wood chords connected together by wood web members and metal web members which provide a strong, durable, beam assembly useful as a joist.
Beams useful as joists have been made of assemblies of wood parts, that is, wood chords and webs. The capability of such wood beam assemblies to support loads, such as directly applied roof loads, tensile and compressive loads, shear stresses and the like, are generally known and can be calculated by those skilled in the art. The maximum load and stress carrying ability of a beam is generally related to the size of the beam, that is, its length and its cross-sectional size, as well as the particular material of which the beam is fabricated. As a general rule, larger loads require larger cross-section beams or more beams of lesser cross-sectional sizes.
The beam of this invention incorporates changes in several of the beam elements which coacting together, substantially increase the load carrying capacity of the beam without increasing the cross-sectional size of the beam or necessitating increasing the quality of the wood used in its construction. One such change is directed towards the wire staples which have been utilized in the past for fastening the wood members together. Such staples have been made of relatively stiff wire that is bent into U shapes. Typically the staples have been connected together into rows or strips which are inserted within conventional stapling guns for application of the staples. Such staples have been used either in place of or along with nails.
Such staples, as well as the commonly used nails, have a tendency to loosen relative to the wood within which they are embedded, particularly due to the expansion, contraction and bending which normally takes place in wood structures. Thus, while stapling is a fast and economical way of making mechanically fastened joints or connections between wood members, a relatively large number of staples are needed to meet particular strength requirements and even then, loosening of the staples can occur over a period of time.
The typical long, U-shaped staples have legs that are considerably longer than their bases or bights. Thus, there is a tendency for the long, relatively wire staple legs to wander off their driven courses during the staple gun insertion which results in their breaking through the sides or edges of the wood members. The exposure of some of the staples through the surfaces of the wood members occurs frequently. The staple of this present invention obviates this problem.
Further, the wood members which are used for beams are typically made of uniform cross-section lumber. Therefore, they are generally of uniform strength along their lengths. Consequently, in order to handle any localized larger forces or loads at specific areas in a joist as compared to areas handling local forces, the wood members must be of a sufficient size throughout their lengths to handle the larger anticipated loads. For example, if a particular anticipated load requires a 2×6 inch beam because of heavy shear stresses at opposite ends of the joist, then the entire beam must be made of that particular size even though other areas of the joist do not require that large a size. Thus, this invention relates to a means for locally increasing the end shear stress bearing capacity of a particular size beam so as to permit the use of smaller cross-sectional size beams or less beams for a particular building construction.
SUMMARY OF INVENTION
The invention herein relates to a composite wood beam assembly made of a pair of horizontal, spaced apart, wood chords joined together by a wood web extending the length of the beam. Wire staples are used to fasten the chords to the web. These staples are formed with beveled free ends that are shaped so as to cause the legs to bend and cross the axis of the staple during insertion into the wood so as to better lock within the wood and prevent staple leg breakouts through the faces of the wood. Moreover, such staples are arranged at predetermined angles to substantially increase the strength of the joints formed by them.
The invention further contemplates utilizing conventional sizes of lumber for the wood chords and webs, but substantially increasing the load carrying capacity of the particular size wood members. First, this includes pre-stressing the lower chords under compression during manufacture of the beam assembly. Second, plates are fastened upon the opposite faces of the web at the opposite ends of the web so as to locally increase the web shear stress capacity, i.e., at the highest shear stress localities.
The use of the wire staples whose legs cross the staple axis and each other as they are inserted into the wood, the compressive pre-stressing of the lower chords, and the provision of the web end plate's thickness in the area or field of highest shear stress, coacting together, substantially increase the strength and load carrying capacity of any particular size beam. This makes it possible to use smaller size beams to handle loads which are beyond those previously contemplated or alternatively, to use less beams than previously required for a particular load.
An object of this invention is to substantially increase the load carrying capacity of any particular cross-sectional size wood beam assembly, without any substantial increase in the cost of the finished beam. This is accomplished: (a) by forming the ends of the legs of the wire staples so that they tend to cross the staple axis during longitudinal penetration into the wood, (b) by compressively pre-stressing the lower chord during the time that the beam chord and web members are assembled together using both adhesive and staples, (c) and by adding plates at the high shear stress fields at the opposite ends of the beam. The improved beam assembly is used in the same way as conventional beams are used in construction. Thus, the essential object of this invention is to substantially increase the strength of a particular beam, without materially affecting its cost or its manner of use.
These and other objects and advantages will become apparent upon reading the following description of which the attached drawings form a part.
DESCRIPTION OF DRAWINGS
FIG. 1 is an elevational view of a composite I-beam assembly, with the staple fasteners schematically shown in dotted lines.
FIG. 2 is an end elevational view of the beam.
FIG. 3 is a perspective, fragmentary view of one end of the wood I-beam.
FIG. 4 is a fragmentary plan view of the end of the beam shown in FIG. 3.
FIG. 5 is a cross-sectional, enlarged, view of a fragment of the beam, taken in the direction of arrows 5--5 of FIG. 4, showing the staples.
FIG. 6 is a cross-sectional view taken in the direction of arrows 6--6 of FIG. 5, to illustrate the position of a staple relative to the upper chord and web.
FIG. 7 is an enlarged perspective view of a single staple.
FIG. 8 is a perspective view of a staple with its legs bent into the cross-axis position resulting from the longitudinal insertion of the staple into the wood.
FIG. 9 is an enlarged, fragmentary, elevational view of the lower end of one of the legs of a staple.
FIG. 10 is an enlarged, fragmentary perspective view of the lower ends of a staple, and
FIG. 11 is a bottom view of the staple leg ends shown in FIG. 10.
FIG. 12 is a schematic view showing the pre-stressing of the lower chord during assembly of the beam.
FIG. 13 is a schematic diagram showing the nature of the shear stress upon a loaded beam.
FIG. 14 is an end view of the beam with an adjacent shear stress force diagram.
FIG. 15 is a perspective view of a row or strip of staples for use in a typical stapling gun.
DETAILED DESCRIPTION
As illustrated in FIGS. 1-3, the composite wood beam assembly 10 is formed of an upper chord 11, a lower chord 12 and a web 13. By way of example, the chords may be formed of 2×4's or other standard size wood strips. In the drawings, the upper and lower chords are illustrated as being formed of 2×4's laid on their sides while the web is formed of a 2×4, or a 2×6, 2×8, 2×10, or 2×12 arranged upright.
The staples 15 (see FIG. 7) are formed of stiff wire bent into U-shapes to provide long legs 16 that are at least several times longer than the base or bight 17 of each staple. The free ends of each of the legs are cut into a face bevel 19 and a small edge chamfer 20, as illustrated in FIG. 9. The angle a of the bevel 19 is preferably in the range of between about 10-14 degrees relative to the axis 21 of the staple. Likewise, the angle b of the smaller chamfer 20 is also preferably in about that same range relative to the bevel, although it may be varied somewhat. The beveled surfaces are also angled slightly, in opposite directions, at roughly the same angles mentioned, relative to the flat plane of the staple. This opposite angling can be seen in exaggerated schematic form in FIG. 10.
The staples may be formed in a group or row 24 (see FIG. 15) similar to conventional staple rows which are used in conventional staple guns. While the staples may vary in size, an example of one suitable size staple is about 31/2 inch long legs, with about a 9/16 inch bight, and formed of stiff steel wire of about 0.080 inches diameter.
When the staples are applied into the wood members for fastening the chords to the web, they are angled relative to the transverse direction of the chords. That is, preferably they are angled at about 30 degrees relative to the transverse direction of the chords (See FIG. 4). In addition, the staples are also angled relative to the vertical, as illustrated by the dotted lines at the opposite ends of the beam in FIG. 1. As shown by the dotted lines, the staples in the upper chord are angled downwardly towards the central axis 25 of the beam, whereas the staples in the lower chord are angled upwardly towards the central axis 25. Preferably, the angularity is roughly around 45 degrees.
As each staple is inserted into the wood by the staple gun, the legs of the staple tend to move towards and then to cross the central axis of the staple. Also, they spread slightly apart relative to each other. This movement is due to the shape of the free ends of the legs. The cross of the legs relative to the staple axis is schematically illustrated in FIGS. 5 and 6. Such crossing of the legs prevents the legs spreading outwardly and breaking out through the side walls of the web or the chords. In addition, the movement of the legs provides a good interlock between the staple legs and the fibers of the wood members. The resulting connection formed by the staple fasteners is considerably stronger and resistant to staple loosening than a conventional stapled joint.
A suitable adhesive 28 (see FIGS. 5 and 6) is applied at the joints formed by the face to face contact of the chords with the opposite edges of the web. The assembly of the wood members, which is schematically illustrated in FIG. 12, includes applying the adhesive or suitable glue upon the opposite edges of the web and, if necessary, the contiguous faces of the chords. The wood parts are placed upon a suitable support table 30 which has compression devices 31. The devices may be in the form of hydraulic or pneumatic cylinders with compression pistons 32, that move sideways towards each other to bear against the opposite ends of the lower chord 12. While the glue is still wet and not yet cured, the lower chord is compressed a pre-determined amount while the web and upper chord are loosely arranged upon it.
Next, the chords are fastened to the web by applying the staples using a conventional stapling gun. To facilitate stapling the lower chord to the web, access openings 33 are formed in the table for the stapling gun. Consequently, when the compression device 31 is released, the beam lower chord remains pre-stressed due to the adhesive and the holding action of the staples.
Because the lower chord is pre-stressed under compression, when the beam is positioned as a joist or header to support loads, the lower chord is placed in tension while the upper chord is placed in compression. The tension forces or stresses of the lower chord are reduced by the amount of the pre-stress compression applied during the assembly. Hence, the lower chord, and therefore, the beam, can handle a much greater tension stress along its lower portion than a conventional beam or joist. Restated, the pre-stressing of the lower chord provides a lower induced tensile stress for any particular load applied to the joist. This increases the maximum tensile stress capacity of a beam, and makes it possible to use the beam to handle a larger load than would otherwise be possible.
Sheer stress plates are applied upon the opposite faces of the web at the opposite ends of the beam, as illustrated in FIGS. 1 and 13. These plates 35 may be formed of plywood that is secured to the web by means of nails, staples or adhesive or combinations of these. Alternatively, a stiff metal plate may be used, as for example a steel, sheet metal plate with struck-out teeth for embedding into the wood. Such metal plates are commonly used as nailing plates to form joints on wood trusses. These plates 35 reinforce the ends of the web in a manner somewhat similar to thickening the ends of the web in the area or field of maximum shear stress. The horizontal lengths of such plates will depend upon the design load of the beam. For example, the plates may be 24 inches long for a 2×10 inch web.
FIG. 13 schematically illustrates a shear stress diagram superimposed upon the beam. The shear stress, designated as S s varies from maximum at the outer ends of the beam to zero in the horizontal plane at the intersection of the beam's horizontal axis 36 and vertical central axis 25. In this diagram, the uniformly applied load is illustrated by the dotted line 37 with the superimposed arrows 38.
The shear stress also varies in the horizontal direction, as indicated in FIG. 14 which schematically shows that the shear stress, in the horizontal direction, varies from a maximum at the horizontal center line to zero at the upper and lower extreme edges or faces of the beam. This is demonstrated by the shear stress diagram 39 in FIG. 14. The shear stress diagrams in FIGS. 13 and 14, taken together, indicate that the maximum shear stress areas or fields are close to the opposite ends of the beam.
It would be economically impractical to make a beam with a web that has a varying thickness or varying strength at its opposite ends in order to handle such increased shear stress. Consequently, the beam shear stress handling capability is determined by the cross-sectional area and strength of the areas at the ends of the web. The shear stress plates 35 secured to the opposite faces of the web are an economically practical way to increase the thickness of the web only in the shear-field or area needed to increase the allowable shear stress handling requirements of a particular size beam. With the shear stress plates, a specific cross-sectional size beam has a considerably greater shear stress handling ability for very little increase in cost. The use of the plates, combined with pre-stressing the the lower chord, permits a beam assembly to handle considerably greater forces. That, along with the considerably greater locking of the parts together by means of the cross-axis staples, produces a substantially improved beam at only a slight cost increase. With this beam, either less beams can be used for a particular load requirement or smaller cross-sectional size beams can be used to meet a particular load requirement. This reduces the overall cost of construction. | An I-beam or joist is formed of a pair of horizontal, parallel wood chords connected together by a wood web. The lower chord is pre-stressed by holding it in compression during assembly of the chords and web. The chords are fastened to the web by U-shaped wire staples whose legs have bevels formed on their free ends which cause the legs to move towards each other and to cross the central axis of their respective staple as they longitudinally penetrate thewood during insertion through a chord and into the wood web. Further, plates are fastened upon the opposite faces of the web at the opposite ends of the web, thereby increasing the web thickness at the opposite ends of the beam to substantially increase the allowable shear stress limits of the beam. | 4 |
This is a continuation of application Ser. No. 08/878,340 filed on Jun. 18, 1997, now abandoned.
BACKGROUND OF THE INVENTION
In construction of a multi-story building, it is necessary to work on the building from the exterior. This is especially true when covering the exterior with a brick veneer constructed from the ground up. It also typically is required to affix window frames, awnings and gutters. It is not uncommon to erect a scaffolding which is the length of the building. Indeed, it is not uncommon to put scaffolding around a building which completely encircles the building. If the building has a rectangular shape of 50 feet by 100 feet and stands 50 feet tall (not uncommon for a four story building), the aggregate length of the scaffolding will represent 300 linear feet on the surface standing 50 feet tall. Personnel often are required to climb up the scaffolding. Sometimes, they can climb on the interior. Often, however, they must climb on the exterior of the scaffolding. This is dangerous to personnel who may slip and fall off the scaffolding. When they fall from the outside face of the scaffolding, they typically will fall onto construction equipment, stacked raw materials and many other things. The injuries from the fall are compounded by the irregular surface area. Moreover, when such a fall occurs, it typically happens when the workman is climbing up the side of the scaffolding and topples over backwards onto his back. The present disclosure is a safety device which protects against this kind of fall. This is true, for buildings, and also tall petrochemical plants.
In protecting the workman climbing on the outside face of scaffolding, the present disclosure sets forth a safety device which is rigged on the scaffolding. It is customary for the scaffolding to be erected from level to level. For instance, the scaffolding is erected to a height enabling construction on the second floor. Then, it is extended up to the third floor as the work proceeds up the building. As it is extended to match the height of the building, or at least approximately so, the additions to the scaffolding enable the workmen to climb up the side. The present disclosure sets forth an overhead device supported on the scaffolding and is directed to an overhead device which supports the workman. Moreover, it is a protective system which enables the workmen to climb up and down the exterior of the scaffolding. While climbing occurs, the workmen are tethered to this apparatus and are protected against falling.
It is such a matter of chance that the fall can be insignificant in many instances and yet can create bodily injury, even death in other instances, from the same height. It is not uncommon for workmen to fall 15 or 20 feet and walk away with no injury. Just as tragically, the same height fall can be fatal to some workmen. It is that irregular risk, wholly unpredictable, that accents the danger and harm that might arise with a fall. When downward movement increases as would occur at the start of a fall, the tether connected to the workmen arrests the fall and holds the workmen. This involves an overhead davit which extends out over the top edge of the scaffolding to extend a cable of sufficient length to reach down to the workmen. The cable is grabbed by the workmen and then latched to a connective ring on a body harness worn by the workmen. The body harness includes appropriate straps so that all the weight of the workmen hangs on the tether line extending from above. Accordingly, as the workmen travel up or down on the exterior of the scaffolding and should fall, the fall is arrested and injury is prevented.
The present disclosure is directed in particular to a demountable davit. It is desirable to mount it at a particular height above on the top edge of scaffolding. Eventually, however, the scaffolding will be extended upwardly by another row of scaffolding members, thereby raising the height. The device of the present invention is detached and remounted. It is moved to the new upper level. As it is moved, it enables workmen on the exterior of the scaffolding to be protected at all times and at greater heights. Again, it is not uncommon to erect the scaffolding as much as 100 feet; even at that height, the workmen can be protected. As one would further understand, as the height of the scaffolding becomes greater, the chance of merely walking away from the fall becomes quite small above about 20 or 30 feet. Indeed, fatal injuries have occurred even at lower heights but they are substantially guaranteed at heights above about 30 or 35 feet. The present apparatus is summarized as comprising an overhead davit which extends outwardly. It has a mounting mechanism which attaches to an upright member of the scaffolding. It is attached by multiple clamps. At the distal end of the davit, there is a reinforced eyelet which supports a retractable tether line equipped to latch on falling. The tether line connects with a harness worn by the workmen. The body harness supports the weight of the workmen.
BRIEF DESCRIPTION OF THE DRAWINGS
So that the manner in which the above recited features, advantages and objects of the present invention are attained and can be understood in detail, more particular description of the invention, briefly summarized above, may be had by reference to embodiments thereof which are illustrated in the appended drawings.
FIG. 1 is a side view of the davit mounted safety system of the present disclosure installed on a multi-story scaffolding system and illustrates the laterally extending overhead davit in conjunction with a full body hardness worn by a user;
FIG. 2 is an enlarged detailed view of the davit which extends outwardly and above the scaffolding; and
FIGS. 3, 4 and 5 show different types of clamp mechanisms for attaching the davit on the scaffolding.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Attention is first directed to FIG. 1 of the drawings where the numeral 10 identifies the present invention which is attached to a scaffolding system. To put the device 10 in context, the description will digress momentarily to the construction site so that the context will be more readily understood. The context begins at the ground 12 which is marginally located around the face of a building 14 . The building 14 can be any height, and for purposes of illustration, it will be discussed in the context of a brick veneer building which incorporates a partially completely brick veneer 16 which extends upwardly to the illustrated height, assumed to be the height of the third floor. The scaffolding at different levels will support temporarily installed horizontal planking 18 such as a set of 2×8's which are shown. These provide temporary decking for the brick layers. Other craftsmen will typically use this also. It is temporary in the sense that it is laid for the moment on the scaffolding to be described. It is placed at this location temporarily and will ultimately be moved to a higher location as the course of bricks raises the brick veneer. The brick veneer 16 is continued until some limitation is encountered. Then, the planking 18 will be disassembled and raised to a greater height in the scaffolding. This is continued indefinitely until the scaffolding extends to the top most height required for building construction. At that juncture, the building is then finished, the planking 18 is removed, and the scaffolding is disassembled. Again, FIG. 1 shows a building but the system can be installed adjacent to a silo, tank, distillation column and the like.
The scaffolding is indicated generally by the numeral 20 . It incorporates a set of vertical legs 22 which terminate at appropriately mounted feet 24 resting on the ground. The feet 24 level the scaffolding so it is erected vertically and parallel to the building 14 . The legs 22 are installed at two rows, one row being right next to the building and the second row is located in parallel fashion but spaced out from the building and is the outer leg. The legs 22 are symmetrically constructed as illustrated in FIG. 1 . Diagonal braces 26 are incorporated. The diagonals in particular serve the function of maintaining the parallel stability of the legs 22 . Periodically, the parallel frame members are additionally reinforced by a horizontal scaffolding member 28 . The horizontal member connects with appropriate connectors in the legs so that the scaffolding can be assembled repetitively to achieve the required height. The horizontal bar 28 serves as a floor support for the planking 18 which is shown further up the scaffolding. Other aspects of the scaffolding need not be illustrated. It is, however, noted that the scaffolding is installed so that it is self-supporting and stabilized. If the scaffolding is erected along a single wall, caution must be exercised to stabilize the scaffolding by attaching the scaffolding to a number of guy wires to assure that it does not wobble. Where the scaffolding is arranged along two, three or four sides of a building, stability is enhanced by connecting the scaffolding on the multiple side walls of the building so that the scaffolding is a continuous member extending around the corner, so to speak. This helps stabilize the scaffolding against toppling.
Assume for purposes of illustration that the scaffolding shown in FIG. 1 extends 40 feet high and the planking 18 is located at a height of 35 feet. The vertical legs 22 are shown as a continuous line but it will be appreciated that they are ordinarily assembled out of individual shorter joints which are threaded to mating couplings. Details of this sort have been omitted from the drawings because they are believed to be well known and understood in the art.
The outer leg 22 is used to support the davit structure. This is better shown on reference to FIG. 2 of the drawings. There, the leg 22 is shown at the left side and is the vertical anchor member. Anchoring is accomplished through the use of at least a pair of protruding horizontal clamps 30 . At least two and sometimes three clamps can be attached to hold the vertical curving davit. FIG. 2 therefore illustrates the upstanding tubular davit which includes the vertical portion 32 and the curved portion 34 . The distal end 36 defines the termination of the davit. This is located where it hangs out over the edge of the scaffolding by approximately 8 to 30 inches. The curved portion extends upwardly at an angle between about 20 and 40°, the preferred angle being an angle of about 30°. The davit is formed of a bent pipe having a nominal diameter of at least about two inches to about three inches. The davit under the bent portion 34 is protected by a gusset plate 38 which is cut to match the contour of the curving pipe 34 and is welded in the curvature. At the distal end, a triangular support gusset 40 is incorporated. A fastener eyelet 42 is formed in it.
FIGS. 3, 4 and 5 show alternate forms of the clamp. Going specifically to the clamp 30 shown in FIG. 3, it incorporates symmetrical halves and is constructed with a davit clamp opening 44 . At the other end, an opening 46 is formed so that the pipe leg 22 can be snugly clamped. Two or sometimes three heavy gauge bolts 48 are used to pull the two halves together so that the clamp mechanism holds firmly to both of the clamped members. The fit should be snug so that the clamp does not slide after fastening.
FIGS. 3, 4 and 5 show different constructions of clamps. FIG. 4 is illustrated to clamp around a rectangular or box leg. FIG. 5 differs in that it shows a leg formed of six sided tubing. In some instances, the clamp will be required to fasten to a H-beam. While the variety of leg shapes for the scaffolding can be accommodated, it is desirable primarily that the opening 46 snugly grip and hold against the scaffolding leg.
The several clamps shown in FIGS. 3, 4 and 5 also illustrate variations in scale which can be implemented. As an example, the openings 44 and 46 can be the same diameter but they can differ in size. Likewise, two or three fasteners can be used. The clamps are preferably constructed with sufficient thickness that they do not bend of flex, and they are further constructed to assure certain clamping at the openings 44 and 46 . Those inside surfaces can be made rough; for example, at the time of fabrication, the openings 44 and 46 can be knurled on the inside to assure a firm grip.
Two or three of the clamps are attached to hold the davit in place. The davit is rotated so that it extends at right angles to the scaffolding 20 . This locates the distal end 36 at an extended location outwardly of the scaffolding. In terms of fabrication, the gusset 38 is contoured to the curvature and has a thickness so that it assures relative stiffness. The welded member 40 is best installed with more than simply a weld along the bottom side of the curving davit pipe 34 . Preferably, the end of the pipe is split so that the member 40 is inserted into the split. It is then welded on the inside of the pipe at the distal end 36 as well as forming left and right beads on the exterior of the pipe 36 . This assures an enhanced connection between the two components.
Attention is now directed to the tether system in FIG. 1 which includes a fall arrester. One such device is provided by the Aros firm and is known as a retractable life line. The model is the G-Series. Continuous tension of a specified amount permits cable to be spooled in or out. The fall arrester 50 includes an upper connective link 52 which is preferably a ring or hook fastening through the eyelet 42 previously mentioned and illustrated in FIG. 2 . The fall arrester 50 encloses a retractable steel cable. Cable lengths ranging from about 20 to about 120 feet are spooled in the equipment. The cable 54 extends downwardly to a fastening ring 56 . Briefly, the device permits the cable to be pulled in or out at a constant but safe velocity. If the cable is pulled downwardly at an increasing velocity, an inertial disk pad braking system is operated to retard cable extension, and arrest downward movement. The system can be adjusted so that the length of the fall is quite short. To avoid jerking the workmen violently, it is desirable that the fall arrester 50 slow down and retard the fall of a workman. To this end, if a workman starts falling, the deceleration leading to absolute stoppage occurs in an adjustable distance and it is preferably about 2 to 4 feet. This assures that the workman is caught quickly and not bounced around, hanging next to the exterior of the scaffolding 20 . The workman is connected with the hook 56 by means of a body harness 60 . The body harness 60 includes a belt 62 and leg straps 64 which loop around and under both legs. It is illustrated from the back in FIG. 1 and incorporates upwardly extending suspenders 66 which terminate at a D-ring 70 . The D-ring connected to the harness holds the entire weight of the person. The D-ring 70 transfers the weight of the workmen to the fall arrester 50 .
The device is used in the following manner. The davit is installed at the raised elevation shown in FIG. 1 of the drawings with the fall arrester 50 suspended from the outer end. The hook 56 is engaged and is pulled downwardly, thereby extending the cable 54 . If need be, a convenient hook 72 is located on one of the legs near the bottom to simply locate and tie off the cable 54 at a convenient height near the ground. For use, the workmen puts on the full body harness 60 . The hook 56 is engaged with the D-ring 70 . While the hook is shown in schematic form, it will be appreciated that it is a closed hook which latches onto the D-ring and holds without risk of accidental disengagement. At this point, the workmen is then able to start climbing up the exterior of the scaffolding 20 . As the workman climbs, the fall arrester spools in the cable 54 . It is stored on a drum or reel which is integral to the fall arrester. As a generalization, the cable is spooled in or out at a controlled minimal velocity. Whether going up or down the scaffolding, the fall arrester cable is maintained taut. The brake in the device is adjusted so that this rate of movement is permitted.
Assume that the workman accidentally falls from the scaffolding at a dangerous height. Immediately, the cable 54 , initially taut, is pulled more rapidly from the fall arrester 50 . When it reaches the set velocity, the inertial brake is applied to the drum and the drum is stopped. The fall of the workman will be just two or three feet before the weight of the workman is held fully by the tethered cable 54 . It is not uncommon that the workman will bounce and swing to and fro. Even if the workman is rotated, the swinging to and fro of the workman on the tethered cable accompanied by rotation will typically spin the workman around so that the workman is able to reach over and grab the leg 22 of the scaffolding, and pull himself back to safety. Once back safely climbing the scaffolding, the workman can then climb upwardly for just a moment, thereby releasing the inertial brake. This will then enable the workman to finish climbing to the top or bottom of the scaffolding as desired.
The scaffolding might thereafter be extended to greater heights. To raise the scaffolding to a greater elevation, scaffolding erection simply continues upwardly as desired. Once the height of the scaffolding is enhanced, typically adding another story in height, the safety apparatus 10 of the present disclosure is momentarily dismounted. This can be done safely by a workman who is located inside the scaffolding and standing on the planking 18 . If desired, the planking can be moved up to another level also. In a safe manner, the clamps 30 are disengaged and the outwardly extending safety davit is then raised to the next height. This requires reinstallation of the two clamps.
If the scaffolding system around the building is quite long, safety davits of the sort shown above are located at several locations. This makes the use of the safety equipment much more convenient for workmen. Typically, two or three different harnesses 60 may be required in the area. If desired, the hook 72 can be used for a convenient hook for the safety harness 60 as well as the cable 54 pulled down from the fall arrester 50 .
While the foregoing is directed to the preferred embodiment, the scope is determined by the claims which follow. | The present disclosure sets forth a safety device for scaffolding so that workmen can climb up or down on the exterior of the scaffolding in safety. The apparatus includes an outwardly extending curving davit having an elevated and radially outwardly extending end supporting, at an eyelet, a fall arrester. The fall arrester is anchored with a hook and an eyelet and has an elongate cable of adequate length extending down to a hook connecting with a D-ring on a body harness for a user. If the user falls, the fall arrester sets a brake preventing the cable from extending, thereby interrupting the fall of the workman. | 4 |
This application is a continuation of application Ser. No. 07/009,595, filed on Jan. 29, 1987, now abandoned, which is a continuation of application Ser. No. 06/719,454, filed Apr. 3, 1985, now abandoned.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a temperature detector for measuring high temperatures, especially suitable for use in a pressurized gas atmosphere of a high temperature about 2000° C., for example, in pressurized sintering furnaces and hot isostatic presses (hereinafter referred to simply as "HIP" for brevity), and more particularly to a thermocouple temperature detector with an improved construction for supporting thermocouple wires.
2. Description of the Prior Art
Recently, large investments are made in the research and development of non-oxide ceramics such as silicon nitride (Si 3 N 4 ) and silicon carbide (SiC) which are looked upon as a high-strength material suitable for application to high-efficiency gas turbines and Diesel engines. In the manufacturing processes of Si 3 N 4 , for example, it has been considered to use a pressurized sintering furnace which holds an N 2 atmosphere of 1800°-2100° C. under pressure of 10-100 kgf/cm 2 , or a HIP apparatus which holds an N 2 atmosphere of 1700°-1800° C. under pressure of 1000-2000 kgf/cm 2 .
With regard to the means for measuring temperatures in such pressurized sintering furnaces and HIP apparatus, it is desirable to employ an optical temperature detector in view of the operation in a high temperature range which in some cases exceeds 1700° C. However, in the case of an optical temperature detector, it is necessary to lead the radiant light from a furnace directly to a sensor portion of the detector. For instance, in a HIP apparatus as shown in FIG. 7, openings 28 and 29 have to be formed through a pressure container 20 with upper and lower lids 21 and 22 and through a heat shielding wall 24 which is located between the inner wall surface of the pressure container and a processing chamber 23 including a support member 25 and a heater 26.
The provision of such opening 28, however, impairs the strength of the pressure container 20, while the opening 29 induces circulation therethrough of the pressurizing gas medium, exposing the inner wall surfaces of the container to a high temperature and as a result inviting large heat losses. The application of the optical temperature detector is therefore substantially difficult, and presently can be found in pressurized sintering furnaces of up to about 10 kgf/cm 2 G.
As a temperature detector for pressurized sintering furnaces and HIP apparatus operating at a pressure level higher than 10 kgf/cm 2 G, there are no suitable temperature detectors on the market except W-Re base thermocouples (e.g., W-Re 5/26 thermocouple, a product of HOSKINS of the United States, 0.5 mm in wire diameter). Accordingly, in the case of a HIP apparatus, attempts have been made to embed, in the heat shielding wall of the pressure container, a commercially available thermocouple which is inserted in an insulating tube and retained at the upper end of thereof, the thermocouple and insulating tube being received in a protective sheath which is closed at the fore end thereof.
However, the conventional method in which the insulating tube and thermocouple are contacted with each other in broad high temperature areas has a problem that is practically difficult to avoid shunt errors due to drops of electric insulation of the tube.
Further, the above-mentioned commercially available thermocouples normally have a small wire diameter of about 0.5 mm, so that, if applied to a HIP apparatus having a diameter of 200 mm and a length of 500 mm and a temperature range up to 2000° C., breakage of the fine thermocouple wire is very likely to occur due to coarsening of crystal grains. Consequently, it is often the case that a thermocouple has a very short service life, enduring only one operation or so. This naturally hinders industrilization of the HIP apparatus of 2000° C. class.
SUMMARY OF THE INVENTION
With the foregoing situations in view, the present invention has as its object the provision of a temperature detector which can improve the accuracy of temperature measurement by a thermocouple and at the same time elongate the service life of W-Re thermocouples, while enhancing the efficiency of the temperature measuring means for furnaces operating under high temperature and high pressure conditions and removing the problems which bar its application to industrial processes.
According to one aspect of the invention, the foregoing objective is achieved by the provision of a temperature detector suitable for use in a high temperature and high pressure furnace, including thermocouple wires received in a tubular protective sheath for protection against the furnace atmosphere, characterized in that the temperature detector comprises: a pair of rod members of a large diameter serving as thermocouple pair for the positive and negative sides thereof; a protective sheath having a rod suspending holder portion in an upper portion thereof for supporting the rod members therein in a vertically suspended state and arranged to hold the rod members out of contact with each other except a temperature measuring point and to contact the protective sheath with the rod members only in a region other than a high temperature region of the furnace.
According to another aspect of the invention, there is also provided a temperature detector for use in a high temperature and pressure furnace, including thermocouple wires received in a tubular protective sheath for protection against the furnace atmosphere, characterized in that the temperature detector comprises: an insulating tube having a rod suspending holder portion in an upper portion thereof for supporting the rod members therein in a vertically suspended state and provided with rod receptacle holes having a greater diameter than the rod members at least in a high temperature region of the furnace to form a clearance between the thermocouple rod members and rod receptacle holes and to suspend the rod members concentrically in the rod receptacle holes substantially in contact-free state.
The above-mentioned thermocouple is mainly made of a W and/or W-Re base material, and the rod members constituting its major components have greater diameter and rigidity as compared with conventional counterparts which are normally about 0.5 mm in diameter, more specifically, the rod members on the positive and negative sides have a diameter larger than 3 mm.
These rod members are provided with screw portions at the opposite ends thereof, which are either threadedly engaged with a rod fastening button or joined by shrink fit or other mechanical means or welded together to constitute a thermocouple pair.
Although the rod fastening button may be made of either a material which constitutes the rod member of the positive or negative side in consideration of the machining operation and strength, it is preferred to be of the material of the negative side which has higher ductility. However, needless to say, it is possible to assemble the thermocouple by the use of a material other than those of the positive and negative rod members, or by the use of a material which is intermediate between the positive and negative rod members in composition.
It is also preferable to use tightening nuts to strengthen the threaded engagement of the rod members with the fastening button. In such a case, the nuts on the positive and negative sides are suitably formed of the materials of the positive and negative rod members, respectively, to prevent loosening due to a difference in thermal expansion coefficient and to produce the thermo-electromotive force stably.
The thermocouple with the above-described construction according to the invention has a large diameter rods which are barely susceptible to breakage caused by coarsening of crystal grains, but they are less flexible as compared with the conventional thermocouple wires. Therefore, if the rod members which are joined at one ends are fixed by insulating members at the other ends or at suitable intermediate portions of the rod members, deformation similar to bimetal may occur due to the difference in thermal expansion coefficient between the two rod members, damaging the rod members by thermal stress in a worse case. For example, a W5% Re alloy has a thermal expansion coefficient of about 5×10 -5 /°C. and a W26% Re alloy has a thermal expansion coefficient of about 8×10 -5 /°C., so that, in the case of 1 m long rod members, the difference of elongation resulting from their thermal expansion amounts to about 6 mm at 2000° C. In order to preclude this problem arising from the difference in thermal expansion between the two rod members, it is desirable to leave the remote ends of the rod members in free state to absorb the rod elongations by thermal expansion.
For this purpose, in a case where the insulating tube is omitted, the thermocouple is supported in the protective sheath by a rod holder portion provided in an upper portion of the protective sheath, the holder portion suspending the thermocouple vertically in the protective sheath without contacting the rod members at least in a high temperature region and in such a manner as to keep the two rod members out of contact with each other at any portion except a temperature measuring point.
In a case where an insulating tube is used, the thermocouple of the above-described construction is inserted in an insulating tube with a couple of receptacle holes to receive the positive and negative rod members, respectively, in such a manner that the rod members are suspended vertically from the upper end of the insulating tube. Although the insulating tube may be constituted by a single elongated tubular body, it is preferred to employ a plural number of short tubes to permit adjustment of the tube length, stacking the short tubes one after another in a suitable length.
In the latter case, it is necessary to stack the short tube sections in concentric relation with each other, and to this end, the insulating tube is preferably provided with a couple of through holes in addition to the above-mentioned rod receptacle holes, inserting aligning rods in the through holes over the entire axial lengths thereof to align them in concentric relation over the entire length in the axial direction. In consideration of its durability at 2000° C., the centering rod is preferably made of a W and/or W-Re material similar to the rod members of the thermocouple.
Furthermore, in addition to the concentric alignment of the rod receptacle holes, the through holes may be used for checking characteristics of electromotive force of the thermocouple, by inserting thereinto the wire of a commercially available thermocouple with approved characteristics, for example, a thermocouple produced by HOSKINS of the United States.
The material of the protective sheath which accommodates the thermocouple is preferred to be BN from the standpoints of durability at 2000° C., machinability and cost. Further, a Mo- or W-base metallic material with a high melting point is peferred from the standpoints of securing an atmosphere for the thermocouple wires, namely, preventing deteriorations of the thermocouple which would result from reaction of a thermocouple with the impurities which creep into the furnace gas from the wall of the protective sheath, or from reaction of a thermocouple with the impurity contents which evaporate from the protective sheath at high temperatures, or for producing the shielding effects against electric noises. For example, where a metallic material of high melting point is used, it is possible to restrict its use only to a high temperature range at a level of about 2000° C., using a metallic material of low melting point such as inconel and stainless steel in a temperature range below 1000° C.
In a case where the insulating tube is employed, it is preferably formed of BN from the standpoints of the durability at the level of 2000° C., machinability and cost as mentioneded above. However, it is also possible to use Al 2 O 3 in a region beneath the thermocouple unit, that is to say, in a region where the temperature is below 1800° C.
On the other hand, in order to secure appropriate properties as a thermocouple, it is necessary to hold same in suspended state without permitting the positive and negative rod members to contact with each other except the temperature measuring point as mentioned hereinbefore. Since the rod members have a diameter larger than 3 mm and sufficient rigidity, this requirement can be easily fulfilled simply by controlling their verticality in the suspending holders. Similarly, the contact of the rod members with the protective sheath or the insulating tube except the suspending holders can be easily avoided.
Namely, in a construction which omits the insulating tube, although the positive and negative rod members are easily kept off contact with each other and with the protective sheath by maintaining their verticality in the suspender holders, it is preferred to provide a more stable construction including a spacer for maintaining a distance between the two rod members at a position beneath the suspender holders. More preferably, the spacer is provided in a low temperature region below the upper end portion of a work support block which serves as a heat insulator on the bottom side of the processing chamber on the HIP apparatus, thereby keeping the rigid thermocouple rod members out of contact with other components in high temperature regions of the processing chamber except the rod suspending holders to preclude shunt errors caused by drops in electric insulation of the spacer at high temperatures. The same applies to the construction which incorporates the insulating tube or tubes, in which the same effect can be obtained by forming the rod receptacle holes of at least one insulating tube in the same diameter as the thermocouple rod members.
Thus, in a case where the insulating tube is not used, the temperature detector is constituted by a protective sheath unit having the rod members of the thermocouple vertically disposed therein in suspended state, and an upper unit closed at one end and mounted on top of the sheath unit for protection of the atmosphere, and the whole body of the detector is located vertically within a furnace chamber. With such a construction, for supporting the rod members of the thermocouple in suspended state in the protective sheath, the upper portion of the protective sheath is formed in a suitable shape, or a rod suspending holder portion of a suitable shape, for example, an inwardly protruding annular projection or projections may be provided on the inner side of the protective sheath in abutting engagement with the rod fastening button.
However, in such a case it is difficult for the thermocouple suspending portion to avoid contact with the thermocouple, so that substances constituting the thermocouple and the protective sheath may invite drops in the thermo-electromotive force by interfusion as a result of the contact, coupled with a demerit that replacement of a used thermocouple becomes difficult due to seizure in a long metallic protective sheath.
As a measure for overcoming these problems, it is preferable to insert a suitable material, taking into consideration its reactivity with the thermocouple suspending portion. Above all, this insert portion can be minimized by adoption of a suitable construction, so that it is possible to select a material of suitable properties, ignoring its machinability and cost. For example, it is possible to employ BeO and ThO 2 which are excellent in electric insulation but problematic for toxicity or radiation, or to employ costly HfO 2 , Y 2 O 3 or the like. Depending upon temperature, there may also be employed Al 2 O 3 or ZrO 2 . A material of this sort may be formed into a shape of a ring or button and mounted on the rod holder portion or on the lower side of the rod fastening button, or alternatively it may be coated on the rod holder portion or on the lower side of the rod fastening button by a suitable coating means such as vacuum vapour deposition, spattering, PVD, CVD, spraying process or the like.
Further, when removing a used thermocouple from a protective sheath after a service, there is possibilities of the component parts of the sheath sticking together without becoming loose. Therefore, it is desirable to employ a construction which permits to insert the thermocouple into the protective sheath from beneath and suspend same by hooking on an upper portion of the sheath.
Where the above-described thermocouple unit employs a long metallic protective tube, it is also desirable to ground the sheath for the purpose of avoiding electric noises on the thermocouple.
Needless to say, the insertion or coating of a heterogeneous material is also applicable to a construction using an insulating tube.
The above and other objects, features and advantages of the invention will become apparent from the following description and the appended claims, taken in conjunction with the accompanying drawings which show by way of preferred embodiments of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
In the accompanying drawings:
FIG. 1(a) is a schematic longitudinal section of a thermocouple unit according to the invention, part of the thermocouple unit being cut away for the convenience of illustration;
FIG. 1(b) is a transverse section taken on line A--A of FIG. 1(a);
FIGS. 2 to 4 are fragmentary longitudinal sections of further embodiments of the invention;
FIG. 5(a) is a fragmentary longitudinal section of another embodiment of the invention;
FIG. 5(b) is a schematic transverse section taken on line A--A of FIG. 5(a);
FIG. 6 is a schematic vertical section of a HIP apparatus incorporating the thermocouple temperature detector according to the invention;
FIG. 7 is a view similar to FIG. 6 but showing a conventional temperature measuring method;
FIG. 8(a) is a schematic longitudinal section of a modified thermocouple unit construction according to the invention;
FIG. 8(b) is a schematic transverse section of the thermocouple unit of FIG. 8(a);
FIG. 9 is a fragmentary longitudinal section, showing thermocouple rod members fitted in rod receptacle holes of an insulating tube;
FIG. 10(a) and 10(b) are a top view and a fragmentary section of the insulating tube taken on line Y--Y of FIG. 10(a);
FIGS. 11(a) and 11(b) and FIGS. 12(a) and 12(b) are top views and fragmentary sections, showing examples of means for concentrically aligning rod receptacle holes of the insulating tube;
FIG. 13 is a schematic longitudinal section, showing another modification of the thermocouple unit according to the invention;
FIG. 14(a) is a schematic section of a HIP apparatus incorporating the thermocouple unit of FIG. 8; and
FIG. 14(b) is a fragmentary section, showing upper and lower parts of the thermocouple unit;
DESCRIPTION OF PREFERRED EMBODIMENTS
Hereafter, the invention is described more particularly by way of preferred embodiments shown in the drawings.
Referring first to FIG. 1, there is shown an example of the thermocouple unit which constitutes a major part of the high temperature detector according to the invention, in which indicated at T is a thermocouple unit, at 1 is a thermocouple of a threaded construction, at 2 is a rod member on the positive side of the thermocouple, and at 3 is similarly a rod member on the negative side of the thermocouple. These rod members 2 and 3 are provided with tapped portions at their upper and lower ends, and have the upper tapped portions threaded into a rod fastening button 4 and fastened to the latter by fastening nuts 5 and 6. The two rod members 2 and 3 in the button 4 are vertically suspended from a holder portion 13 which is provided in an upper portion of a protective sheath 12 which receives the rod members, while a spacer 14 of an insulating material which serves up to maintain a distance stably between the two rod members 2 and 3 is located in a lower portion of a low temperature region where the spacer can ensure sufficient insulation, thereby forming the afore-mentioned thermocouple 1. Nuts 7 and 8 of the same material and shape as the nuts 5 and 6 are tightly threaded on the lower tapped portions at the lower ends of the rod members which are projected downward through the spacer 14, the nuts having lead wires 9 and 10 attached thereto to facilitate connection to a temperature recorder which is not shown.
An upper protective sheath 11 which is closed at its upper end is capped on the main protective sheath 12 which is arranged in the above-described manner, thereby to shielding off the atmosphere.
With regard to the materials for the rod members 2 and 3 in the above-described thermocouple construction, the rod member 2 of the positive side is formed of a W or W-Re base material such as W-3%Re or W-5%Re. On the other hand, the rod member 3 of the negative side is formed of a material corresponding to the material of the positive rod member 2, for example, of W-26%Re for a positive rod member of W or W-5%Re or of W25%Re for a positive rod member of W-3%Re in normal cases. The rod diameter is preferred to be greater than 3 mm for securing sufficient rigidity of the rods and facilitating the operation of screw tapping, especially, the female screw tapping, and in consideration of the expected length of service life when applied to industrial equipments.
The afore-mentioned fastening button 4 into which the rod members are threaded is provided with female screw portions in two spaced positions as shown particularly in FIG. 1(b), and normally made of a material same as the positive or negative rod member or a material intermediate between the positive and negative rod materials in composition. Of the nuts 5 to 8, those on the positive side are made of the same material as the positive rod member 2 and those on the negative side are formed of the same material as the negative rod member 3.
The lead wires 9 and 10 which facilitate the connection of the large-diameter rod members 2 and 3 are made of, for example, 0.5 mm compensating lead wires for W-Re produced by HOSKINS of the United States.
Illustrated in FIGS. 2 to 5 are further embodiments of the invention, which are same as the foregoing embodiment in basic construction and in which like component parts are designated by like reference numerals.
The embodiment of FIG. 2 employs a protective sheath consisting of an upper portion with a rod suspending holder 13 and a lower section 12b without such a rod holder portion, for the purpose of facilitating the machining operation of the rod suspending holder 13 to be provided in the upper portion of the protective sheath.
In the embodiment of FIG. 3, an upper spacer ring 14' of a material different from the protective sheath is inserted between the rod suspending holder 13 and the fastening button 4 to prevent deteriorations in thermo-electromotive force due to interfusion of metals which might be caused by contact of the rod members with the rod suspending holder in a case where the latter is made of a metal, or to prevent seizure of a used thermocouple in other metallic components which makes replacement of the thermocouple difficult.
Referring to FIG. 4, there is illustrated an embodiment in which a button-shaped upper spacer 14' is mounted on the side of the thermocouple to produce the effects similar to the spacer 14' of FIG. 3. A spacer of a heterogeneous material may be either inserted as a separate part as shown in FIGS. 3 and 4, or deposited on the upper or lateral side of the rod suspending holder 13 or on the lower or lateral side of the rod fastening button 4 by a coating process even in the case of the thermocouple construction shown in FIG. 1.
Illustrated in FIG. 5 is a further embodiment in which the rod suspending holder 13 and fastening button 4 are formed in the shapes of FIG. 5(b) in plane view, suspending the thermocouple on the holder 13 by turning the rod fastening button 4 through 90° after inserting the thermocouple into the protective sheath from beneath. This rod holder construction is applicable to the embodiments of FIGS. 3 and 4 to facilitate replacements of used thermocouples even in a case where disassembling of the protective sheath becomes difficult after service at high temperatures, and thus to reduce the running cost.
FIG. 6 shows an example of application of the thermocouple temperature detector, namely, a HIP apparatus having the thermocouple mounted in a high temperature and pressure furnace of a HIP apparatus by a support member 27 at a position on the inner side of a heat insulating wall 24. In this particular example, the support member 27 is made of a metallic material, and may be electrically short-circuited to the lower lid of the high pressure container to utilize the electric shielding effect of the protective sheath, thereby to provide a stable temperature detector which is free of the influence of electronic noises which are produced upon turning on a power switch.
Referring now to FIGS. 8(a) and 8(b), there is shown a further embodiment which is same as the first embodiment of FIG. 1 except that the rod members 2 and 3 joined by the coupling button 4 at the upper ends are received and suspended in rod receptacle holes 33 and 33' of an insulating tube 31 which is constituted by a number of concentrically stacked, short tubular sections and accommodated in a protective sheath 12.
The rod receptacle holes 33 and 33' of the insulating tube 31 are formed in a diameter appreciably larger than the rod members 2 and 3 of the thermocouple, and it is important in this case that the rod receptacle holes 33 and 33' of the respective tubular sections are stacked in the axial direction in concentric alignment with each other as shown in FIG. 9.
As a material for the insulating tube 31, there may be employed BN for use at a level of 2000° C. and Al 2 O 3 for use at a level lower than 1800° C.
Illustrated in FIGS. 10 to 12 are modified constructions including means for concentrically aligning the tubular sections of the insulating tube 31. In the modification of FIG. 10, the tubular sections of the insulating tube 31 are provided with a pair of through holes 34 and 35 in alignment in the axial direction in addition to the rod receptacle holes 33 and 33', and aligning rods of a W and/or W-Re material similar to the rod members of the thermocouple are inserted in these through holes along the entire length thereof. On the other hand, in the modification of FIGS. 11 and 12, the insulating tube 31 is provided with means which is capable of testing by an approved commercially available thermocouple, in addition to the concentric alignment of the rod receptacle holes 33 and 33'. Namely, the insulating tube is provided with holes 37 and 38 for receiving the wires of an approved thermocouple, with a sunken portion 39 on the uppermost end face of the tubular sections across the wire holes 37 and 38 to receive the fore end of the approved thermocouple T'.
FIG. 13 shows a further modification of the thermocouple temperature detector of the invention, wherein a spacer 16 of a material different from the insulating tube 31 and having a couple of holes is interposed between the uppermost end of the insulating tube 31 and the fastening botton 4 to improve the accuracy of measurement by preventing drops in thermo-electromotive force due to contact between the thermocouple and the insulating tube during use over a long period of time.
Similarly to the foregoing embodiments, the thermocouple unit with the above-described modified construction is located, for example, in a high temperature and pressure container of a HIP apparatus by a support member on the inner side of a heater 26 which is mounted inward of a heat insulating wall 24.
In this instance, the rod members 2 and 3 are supported in suspended state within the rod receptacle holes 33 and 33' of the insulating tube 31, leaving a gap space around the rod members 2 and 3 as they are smaller in diameter than the rod receptacle holes 33 and 33'. In the case of the thermocouple shown in FIG. 8, the rod members 2 and 3 are disposed almost clear of the insulating tube, contacting the latter only at an upper point B. (See the upper tubular section of FIG. 14(b).)
Namely, the rod receptacle holes 33 and 33' in at least one tubular section 31a which is located in a region below the upper end A of the work support block 25, which also serves as heat insulation on the lower side of the furnace chamber 23, are formed in a diameter substantially same as that of the rod members 2 and 3 (see the lower tubular section of FIG. 14(b)). Therefore, even if they are in contact with each other at that tubular section, the rigid rod members 2 and 3 are contacted with the insulating tube 31 or its tubular sections 31a only at the point B of FIG. 8 in high temperature regions, thus precluding shunt errors which would be caused by drops in electric insulating characteristics of the insulating material.
In a case employing a combination of a thermocouple of W-Re and an insulating tube of BN, the tubular section 31a with the narrower rod receptacle holes 33a and 33a' is preferred to be located in a temperature region lower than 1600° C. in consideration of the electric insulation resistivity of the insulating tube of BN which drops at temperatures higher than 1600° C.
However, since the object of the present invention can be achieved as mentioned hereinbefore in spite of the contact of the thermocouple rod members with the insulating tube at the point B of FIG. 8, it is preferred to avoid the contact even when the rod receptacle holes at the point B of the uppermost insulating section are formed in a smaller diameter, for the purpose of preventing shunt errors. The intended effects can be obtained in a sufficient degree unless the contact takes place in a region other than the uppermost portion.
Following are the results of tests on the thermocouple temperature detector according to the present invention.
TEST EXAMPLE 1
For thermocouple wires, there were expeimentally produced W-5%Re and W-26%Re rod members of 3 mm in diameter and 800 mm in length, with screws of M3×0.5 at the opposite ends thereof. There were also obtained fastening buttons of W-26%Re, nuts of W-5%Re and W-26%Re from the same lots as components for assembling the thermocouple rod members.
On the other hand, the protective sheaths for holding and suspending thermocouple rod members in a shielded state were produced from tungusten. Each thermocouple unit was assembled by suspending a thermocouple in a protective sheath and fitting an insulating spacer in a lower portion of the protective sheath in such a manner as to maintain a distance between the thermocouple rod members. Accordingly, the contact between the rod members of the thermocouple and the protective sheath was limited to the suspending holder portion. The resulting thermocouple unit was mounted on a HIP apparatus and subjected to a repeated endurance test of Ar 1000 kgf/cm 2 ×2000° C.×1 hr. For the purpose of comparison, W-Re5/26 thermocouples with wire diameters of 0.5 mm and 1.0 mm (products of HOSKINS) were inserted into insulating tubes according to the usual procedure, suspending each thermocouple from an upper portion of the insulating tube. These insulating tubes each with a thermocouple therein were fitted in protective sheaths which were closed at the respective fore ends, to obtain thermocouple units for use as test samples in a similar endurance test. According to the test results, the thermocouples of 0.5 mm and 1.0 mm wire diameters proved to have short service life lengths corresponding to only one cycle and 2-3 cycles of operation, respectively, in contrast to the thermocouple unit samples according to the invention which could endure at least 23 cycles of operation with an accuracy guarantee of ±1.0%.
TEST EXAMPLE 2
Spacers of BeO, ThO 2 , HfO 2 and Y 2 O 3 were inserted respectively into the thermocouples of the above-described construction for endurance test.
As a result of a repeated endurance test of Ar 1000 kgf/cm 2 ×2000° C.×1 hr, any one of the above-mentioned combinations proved to have a service life of at least a length corresponding to 25 cycles of operation with a accuracy guarangee of ±1%, and the thermocouples could be easily extracted after use.
As clear from the foregoing description, the present invention is directed to a thermocouple temperature detector suitable for use in a high temperature and pressure furnace, the temperature detector employing a thermocouple consisting of a pair of rod members of a diameter larger than ordinary thermocouple wires and a protective sheath having a holder portion adapted to support the rod members in suspended state in the protective sheath without contacting the rod members at least in high temperature regions. Alternatively, the rod members are inserted in an insulating tube with rod receptacle holes of a larger diameter to support the rod members in suspended state almost without contacting them. As the thermocouple wires consist of rod members of a large diameter, it becomes possible to improve the service life of the thermocouple to a considerable degree, elongating the length of service life up to the wire breakage due to coarsening of crystal grains and increasing the resistivity to contamination with impurity components of the atmosphere gas. Consequently, the present invention has a conspicuous effect in reducing the frequency of thermocouple replacements to get the maximum performance of each thermocouple unit under high temperature and pressure condition, and facilitating the industrial processes utilizing a furnace of high temperature and pressure like HIP apparatus. Since the thermocouple temperature detector construction of the invention limits the contact between the thermocouple rod members and the insulating tube to an extremely small area at the upper end of the insulating tube or completely dispenses with the insulating tube, the shunt errors which would be caused by drops in electric insulation property of the insulating tube can be prevented to ensure practical temperature measurement of high accuracy.
In addition, the rod members of the thermocouple which are suspended from a holder portion at the upper end of the insulating tube or protective sheath have the respective lower portions in free state almost or completely free of contact with the insulating tube, so that the elongations of the respective rod members by thermal expansion can be absorbed by the lower portions, without inviting damages as caused to conventional thermocouples of this sort as a result of thermal expansion.
Although BN protective sheaths are suitable particularly for use in an N 2 gas atmosphere, metallic protective sheaths are preferable from the standpoints of improvement of strength, retention of a clean atmosphere in the sheath and prevention of electric noises on the thermocouple.
Further, the insertion or coating of a heterogeneous material on the rod suspending portion prevents deteriorations of the performance quality of the thermocouple caused by diffusion of substances as a result of contact between the thermocouple and the suspending portion, or prevents seizure of the thermocouple which would make its replacement difficult. | A temperature detector for use in a high temperature and high pressure furnace, including thermocouple wires received in a tubular protective sheath for protection against the furnace atmosphere, and characterized by the provision of a pair of rod members of a large diameter serving as a thermocouple pair for the positive and negative sides thereof, a protective sheath having a rod suspending holder portion in an upper portion thereof for supporting the thermocouple rod members therein in a vertically suspended state and arranged to hold the rod members out of contact with each other except at a temperature measuring point and to contact the rod members with the protective sheath only in a region other than a high temperature region of the furnace. | 1 |
This application claims the benefit of U.S. Provisional Application No. 60/591,938 entitled ELECTROLUMINESCENT BRAIDED PET LEASH, filed Jul. 28, 2004.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to pet leashes; and more particularly, to an electroluminescene wire illuminated pet leash especially suited for use during dusk or nighttime hours to enhance the safety of pets and their owners while walking in dimly lit environments where rapidly moving vehicles are encountered.
2. Description of the Prior Art
Walking a pet during dusk or nighttime hours can be hazardous in neighborhoods where automobiles are encountered. Illuminating characteristics of the automobile headlamps, generally afford an illumination range of approximately 25 to 50 feet. This illumination range can be significantly reduced by mist or fog, or bends in the road. Despite improvements to vehicle headlights, pets and their owners are oftentimes not recognized by automobile drives until the distance between the automobile and the pet is small.
Several approaches devised by prior art workers attempt to provide solutions for this hazardous common activity. These approaches include 1) use of pet collars that are illuminated or reflective; 2) use of leashes which are illuminated or reflective; or 3) a combination of both features. None of these solutions suggest indicating the whereabouts of a pet owner, a leash and a pet attached to the leash via a flexible, spirally wound electroluminescent illuminator.
Various types of reflectively illuminated dog collars and leashes are known in the art. These reflectively illuminated dog collars and leashes are not equipped with batteries, light bulbs or other lighting elements; but depend instead on light from an external source to trigger reflective illumination. Rapidly moving vehicles, such as bikes, scooters, joggers and the like, encountered by pets and their owners while walking in dimly lit environments such as bike paths, country roads, parking garages and the like, are not always equipped with light emitting equipment. Within these environments, the advantages of power-illuminated dog collars and leashes over those of the reflective variety are readily apparent.
U.S. Pat. No. 3,871,336 to Bergman discloses a reflective dog collar which is not illuminated but which utilizes a highly reflective material in the form of dots of different colors that are encapsulated in plastic. U.S. Pat. No. 3,999,521 to Puiello discloses a reflective safety harness for quadruped animals. The safety harness includes a pair of identical sheet elements with a light reflective surface mounted on opposite sides of the animal. U.S. Pat. No. 4,167,156 to Kupperman et al. discloses a reflective animal leather leash with a transparent polyvinyl chloride strip having a light reflective prism design on one surface. U.S. Pat. No. 4,384,548 to Cohn discloses a safety device for animals via a pet collar. The pet collar utilizes “retro-reflective” threads with glass reflective elements in a flexible webbing to form a pet leash. U.S. Pat. No. 4,407,233 to Bozzaco discloses a safety collar for pets that has highly reflective flexible elements large enough in length to extend beyond the outer surface of the pet's hair. U.S. Pat. No. 6,070,556 to Edwards discloses an illuminating dog safety system that comprises a pet collar having a reflective strip that extends the majority of the collar's length. The safety system further comprises a harness adapted to be worn around an animal's torso and having upper and lower reflective straps.
Various types of illuminated dog collars are known in the art. Some of these heretofore devised and utilized illuminated dog collars employ bulb or other power sources for illumination. Representative dog collars of this variety are discussed below.
U.S. Pat. No. 4,173,201 to Chao, et al. discloses an illuminated collar for pets and the like. The disclosed collar is adapted to be worn by a dog, cat, or other domesticated animal. The collar includes a row of small electric lamps studded around the collar in a manner inducing visibility in darkness or subdued daylight. The circuitry includes a replaceable dry cell battery and a manually operated switch which is mounted on the collar. The disclosed collar is not illuminated by way of an electroluminescent wire illuminated device, but instead utilizes a bulb device.
U.S. Pat. No. 4,513,692 to Kuhnsman et al. discloses an illuminated pet leash comprising a non-opaque tube that contains one or more bundles of optical fibers. A light bulb is connected adjacent to the leash handle to shine light into the tube and illuminate the optical fibers therein. The pet leash is not illuminated by an electroluminescent wire device, but instead is illuminated by a fiber-optic illumination device. Specifically, the fiber-optic illumination device functions to redirect light from a bulb power source and not from an electroluminescent wire.
U.S. Pat. No. 4,895,110 to Lo Cascio (hereinafter, the '110 patent) discloses a pet collar that includes a light source and a power source attached to a strap. A closure device for the collar acts as a switch, such that power is provided to the light source to illuminate the collar when the ends of the collar are connected by the closure device. The light source utilized by the '110 patent is not that derived from an electroluminescent wire illuminated device.
U.S. Pat. No. 4,887,552 to Hayden discloses an electrically lighted pet leash that is composed of a transparent, flexible tube containing a string of small electric light bulbs mounted in parallel between two insulated wires. The leash is looped at one end to form a choker collar and at a second end to form a handle. The string of lights extends throughout the leash to illuminate both the collar and the handle. A small rechargeable battery is mounted adjacent to the handle for operating the lights. The patented device does not utilize an electroluminescent wire illuminated device, but rather utilizes a small bulb lighted device for illumination.
U.S. Pat. No. 5,046,456 to Heyman et al. discloses an illuminated pet collar in which multiple lights are mounted within a flexible, light-permeable tube that extends about the perimeter of the collar. A housing mounted on one end of the tube contains a circuit and a battery for operating the lights. This multiple light device does not use an electroluminescent wire illuminator in the pet leash.
U.S. Pat. Nos. 5,074,251 and 5,140,946 to Pennock et al. discloses an illuminated pet collar. The illuminable pet collar includes a housing for a battery power source and an elongated, flexible, pliable, transparent plastic display tube having a plurality of miniature lights spaced apart and operably connected therewithin along substantially the entire length of the display tube. The housing includes a stem or extension tube extending from each end thereof that is sized to be snugly inserted into each end of the display tube. Electrical connection between the battery and the outer surface of one stem communicates electrical power to the lights, which are parallel-wired within the display tube. The source of illumination does not involve an electroluminescent wire and instead the patent utilizes a miniature light illumination device.
U.S. Pat. No. 5,243,457 to Spencer discloses material with enhanced visibility characteristics. This flexible visibility enhancing material is provided combining the advantages of a light reflective component and a luminescent component. The material includes a first layer of prismatic light reflective plastic material having an underlying surface formed with a plurality of minute prism-like formations projecting therefrom at regular spaced intervals and an overlying substantially smooth light transmissive surface. Bonded, as by heat sealing, to the first layer is a second layer of plastic luminescent material contiguously and integrally attached to the underlying surface of the prism-like formations, and generally coextensive therewith. The visibility enhancing material simultaneously radiates luminescent light from the second layer, through the underlying surface of prism-like formations, and further through the smooth light transmissive surface. Light is reflected from the prism-like formations through the smooth light transmissive surface. In one embodiment, a leash for controlling and restraining a pet animal includes a flexible elongate member comprised of the visibility enhanced material. In another embodiment, the second layer is replaced with a layer of luminescent material, which can be selectively energized to become luminous. Since the transparent reflective material is a molded plastic of prismatic construction it is rigid with the electroluminescence light source positioned underneath the rigid transparent material. The disclosed device is inflexible and is not readily capable of being twisted and flexed. Furthermore, any twisting and bending action would result in separation of the reflective element from the luminescent element.
U.S. Pat. No. 5,237,448 to Spencer et al. discloses visibility enhancing material that combines the advantages of a light reflective component and a luminescent component. The material includes a first layer of prismatic light-reflective plastic material having an underlying surface formed with a plurality of minute prism-like formations that project therefrom at regular spaced intervals and an overlying substantially smooth light transmissive surface. A second layer of plastic luminescent material is contiguously and integrally attached to the underlying surface of prism-like formations and generally coextensive therewith. The visibility enhancing material simultaneously radiates luminescent light from the second layer through the underlying surface of the prism-like formations and through the smooth light transmissive surface. Light is reflected from the prism-like formations through the smooth light transmissive surface. In one embodiment, a leash for controlling and restraining a pet animal includes a flexible elongate member comprised of the visibility enhanced material. Since the transparent reflective material is a molded plastic of prismatic construction it is rigid with an electroluminescence light source positioned underneath the rigid transparent material. The leash device disclosed in the patent does not have flexible properties and therefore is not readily capable of being twisted and flexed. Further any twisting and bending action will undesirably cause the reflective element to separate from the luminescent element.
U.S. Pat. No. 5,370,082 to Wade (hereinafter, the '082 patent) discloses an animal collar that includes the utilization of illuminating devices. These illuminating devices include light emitting diodes, liquid quartz strips, or electric lamps. A plurality of solar cells are provided on the outside of the collar and function to recharge the power supply connected to the illuminating devices. The '082 patent does not utilize an electroluminescent wire illumination device, but rather utilizes light emitting diodes, liquid quartz strips, or electric lamps for illumination. U.S. Pat. No. 5,429,075 to Passarella et al. discloses a pet leash and flashlight combination. This flash light integrated pet leash is not an electroluminescent wire illuminated pet leash.
U.S. Pat. No. 5,523,927 to Gokey discloses an illuminated animal collar. The illuminated collar comprises: a collar for placement on an animal; at least one light emitting diode placed on the outer exterior of the collar to be visible when the collar is worn; a motion sensitive switch designed to respond to the motion of the animal an on/off switch to selectively turn on or off battery power to the circuit; a battery; a timing circuit; and a low battery power detection circuit. The light emitting diodes, motion sensitive switch, on/off switch, battery, timing circuit and low battery detection circuit are connected together. An intermittent flashing of the light emitting diodes will thus be established for constant movement. The low battery detection circuit sounds an audible alarm to warn the user of a low battery. The disclosed illuminated collar is illuminated by means of a diode and is not illuminated by way of an electroluminescent wire illuminated device. Furthermore, the patent does not disclose an illuminated pet leash.
U.S. Pat. No. 5,535,106 issued to Tangen discloses a lighted animal collar that includes a plurality of separate light emitting assemblies or housings at spaced intervals along the collar. Each of the assemblies includes a light emitting diode, battery source, reflectors and a translucent cover. This lighting assembly illuminated collar does not suggest an illuminated pet leash and collar. Moreover, the collar is not illuminated by way of an electroluminescent wire illuminated device.
U.S. Pat. No. 5,558,044 to Nasser, Jr. et al. discloses illumination of a leash handle by way of a flashlight. The flashlight is attached to the top portion of the handle, in a forward-facing direction, such that the light beam from the flashlight can be pointed in any desired direction by the hand holding the leash. The illumination device does not use an electroluminescent wire to illuminate the leash, but rather utilizes a flashlight device. The flashlight acts to illuminate the leash handle by localizing the light beam in the direction the leash is pointed.
U.S. Pat. No. 5,630,382 to Barbera et al. (hereinafter, the '382 patent) discloses an illuminated pet harness having straps with internal cavities that contain fiber optic cores. A plurality of lenses are provided on a top layer of the straps for projecting light when the fiber optic core is illuminated by a light bulb. The '382 patent's illumination device employs fiber optic illumination rather than illumination via an electroluminescent wire device. Furthermore, the invention discloses the illumination of a harness and does not further disclose the illumination of a pet leash.
U.S. Pat. No. 5,762,029 to DuBois et al. discloses a combined retractable leash and flashlight which is an apparatus having a retractable leash and an integral light. The apparatus has a housing section with a handle and a light connected to the top front. A rechargeable battery is removably connected to the housing in the handle. The retractable leash section is pivotally mounted to the housing section. A leash is connected to the reel for extension and retraction relative to the housing section. The retractable leash flashlight combination device does not use an electroluminescent wire for illumination.
U.S. Pat. No. 5,850,807 to Keeler discloses an illuminated pet leash for allowing a pet owner to easily and remotely locate the pet leash. The device includes an elongated non-opaque tube having a bundle of optical fibers longitudinally disposed therein and being illuminated by a remote transponder operable in locating the pet leash. This is not an illuminated leash for walking a dog in a darkened environment. This is a remotely activated pet leash finer and does not use an electroluminescent wire for illuminating a pet leash while a pet is being walked during night-time hours.
U.S. Pat. No. 5,967,095 to Greves (hereinafter, the '095 patent) discloses an illuminated pet leash provided with an elongated strap at one end that is adapted for connection to a collar, and a second end adaptable for forming a handle. A relatively flat and flexible light source is provided along one side of the strap for illuminating the leash. The light source is operated by a power source attached to the strap. The light source is a flat strip of electroluminescene type and may be either permanently or releasably attached to the strap. In another embodiment, the elongated leash strap has two light sources extend along both of its sides. In yet another embodiment, the elongated strap is round in cross-section, and the light source spirals around the circumference of the strap for the extent of the leash. In another embodiment, the illuminated pet leash includes an elongated strap having at least one side, and first and second ends. One end of the strap is attached to a handle having a grip portion and a housing portion with first and second sides. A pair of light sources are positioned on the sides of the housing, and are electrically connected to a power source to illuminate the handle. The pair of light sources are either attached directly to the handle, or to a cover that is attached to the handle. The light sources on the handle or cover are formed in a variety of patterns such as circular, spiral or zig-zag formation. The electroluminescent devices used in the '095 patent disclosure are flat and are generally inflexible in nature, as opposed to an electroluminescent wire which is not disclosed.
U.S. Pat. No. 6,170,968 to Caswell discloses a motion activated rotatable illuminator. The disclosed illuminator has all of its electrical components mounted within a housing that is secured to the rotatable object. Those components include a light source, an electrical power source, a first switch activated by intermittent motion of the housing and a second switch activated by centrifugal forces caused by rotation of the rotatable object. The illuminator components also include a timer which has a timing cycle and which is operably connected relative to the first switch and the second switch such that activation of either the first switch or the second switch initiates that timing cycle of the timer and enables the flow of electricity from the power source to the light source during the timing cycle. The light source can include an electro luminescent strip or light emitting diodes. As noted the illuminator can be mounted on a rotatable object, or can be used by wearing on a person, pet or other device to provide a warning or locator light. The electroluminescent device used is a strip, not an electroluminescent wire and therefore is not very flexible or twistable.
U.S. Pat. No. 6,289,849 to Macedo et al. discloses a device to removably attach a flashlight to a retractable dog leash. The device includes a flexible elongated base member having a top and a bottom side. An elastic member attached to the top side of the elongate member creates an aperture there between for removably inserting a flashlight. Two straps are attached to the bottom of the based member for detachably connecting the elongated base member to a handle of the retractable leash. This flashlight attached pet leash does not use an electroluminescent wire illumination in the pet leash.
U.S. Pat. No. 6,557,498 to Smierciak et al. discloses a night safety pet illumination marker. In this disclosure, a pet collar forms a linearly elongated substrate spine upon which are mounted a series of illumination elements comprising light emitting diodes around the perimeter of collar powered by battery power. A light sensor switch is in series between a power source and the illumination elements breaks the electrical circuit upon sensing of sufficient ambient light levels. The illumination elements may be flashed with a timing circuit. The light emitting diodes may be placed along length of leash controlled by an on/off/automatic switch with light sensor. The patent does not disclose a pet leash, but discloses a diode illuminated collar. Furthermore, the disclosed illuminated collar does not use an electroluminescent wire illumination device, but instead utilizes a diode illumination device.
Numerous patents disclose different types of retroreflectors. However, only those reflective devices that have a flexible nature, and therefore suited for pet leashes, are discussed below.
U.S. Pat. No. 4,763,985 to Bingham discloses a launderable retroreflective appliqué that comprises a layer of transparent microspheres, a specular reflective layer optically connected to each microsphere, and a binder layer into which the microspheres are partially embedded. Resins disclosed as being suitable for use as binder layers include polyurethane, polyesters, polyvinyl acetate, polyvinyl chloride, acrylics, or combinations thereof. The specular reflective layers are composed of two succeeding layers of dielectric material. The layers have varying refractive indices and are composed of a variety of binary metal compounds including oxides, sulfides, and fluorides.
U.S. Pat. No. 4,957,335 to Kuney discloses microsphere-based retroreflective articles having high retroreflective brightness at narrow divergence or observation angles, i.e., up to 0.5 degrees. The article made by selection of microspheres having defined combinations of average diameter and average refractive index. This patent teaches (column 4, lines 18-23) that variation in the size of the microspheres will increase the observation angle or divergence angle of the resultant retroreflective article.
U.S. Pat. No. 5,117,304 to Huang et al. discloses a retroreflective article. The retroreflecive article has corner cubes and flexibility. The article can be applied over irregular surfaces by using an optically clear, aliphatic polyurethane polymer. The aliphatic polymer has a plurality of hard chain segments of the formula —C(O)N(H)—C 6 H 10 —N(H)C(O)—.
U.S. Pat. No. 5,200,262 to Li discloses a launderable retroreflective appliqué. The appliqué employs a reflector that comprises elemental aluminum or elemental silver on the backside of the microspheres. The appliqué comprises a monolayer of metal-coated microspheres partially embedded in and partially protruding from a binder layer that comprises a flexible polymer having hydrogen functionalities and one or more isocyanate-functional silane coupling agents. The disclosed flexible polymers include urethane-based polymers such as isocyanate-cured polymers or one or two component polyurethanes and polyols.
U.S. Pat. No. 5,283,101 to Li discloses a launderable retroreflective appliqué which comprises a binder layer formed from an electron-beam curable polymer and typically one or more crosslinkers and silane coupling agents. Electron-beam curable polymers include chlorosulfonated polyethylenes, ethylene copolymers comprising at least about 70 weight percent of polyethylene such as ethylene/vinyl acetate, ethylene/acrylate, and ethylene/acrylic acid, and poly(ethylene-co-propylene-co-diene) polymers. Glass microspheres are embedded in the cured binder layer, and a specular reflective metal layer is disposed on the embedded portions thereof. This appliqué is inverted and light comes through the binder layer.
U.S. Pat. No. 5,777,790 to Nakajima discloses a microsphere-based retroreflective article. The retroreflective article comprises a monolayer of microspheres partially embedded in, and protruding from, a binder layer and specular reflector underlying the microspheres, wherein the monolayer of microspheres comprises a mixture of a first class of microspheres having a first refractive index and a second class of microspheres having a second refractive index wherein the second refractive index is higher than the first refractive index. As a result, the sheeting exhibits superior observation angle angularity.
U.S. Pat. No. 5,962,108 to Nestegard et al. discloses a retroreflective polymer coated flexible fabric material and method of manufacturing the same. The retroreflective polymeric coated flexible fabric material has a retroreflective layer and a polymeric compatibilizing layer welded to a polymeric coated outer surface of a flexible fabric material. The compatibilizing layer provides an intermediate layer between the retroreflective layer and the flexible fabric material, creating suitable bond strength between dissimilar polymers. Flexible fabric materials are polyester, nylon or cotton. The fabric is coated with highly plasticized polyvinyl chloride (PVC) or ethylene acrylic acid copolymer (EAA) that are flexible, durable, and resistent to abrasion. The retroreflective prismatic elements layer include acrylic polymers such as poly(methylmethacrylate); polycarbonates; cellulosics; polyesters such as poly(butyleneterephthalate); poly(ethyleneterephthalate); fluoropolymers; polyamides; polyetherketones; poly(etherimide); polyolefins; poly(styrene); poly(styrene) co-polymers; polysulfone; urethanes, including aliphatic and aromatic polyurethanes; and mixtures of the above polymers such as a poly(ester) and poly(carbonate) blend, and a fluoropolymer and acrylic polymer blend. The compatibilizing layer that is suitable for bonding between a retroreflective layer and a flexible fabric material include polyurethane, ethylene methyl acrylate copolymer, ethylene N-butyl acrylate copolymer, ethylene ethyl acrylate copolymer, ethylene vinyl acetate copolymer, polymerically plasticized PVC, and polyurethane primed ethylene acrylic acid copolymer. This is a reflective fabric, not a pet leash.
U.S. Pat. No. 5,485,355 to Voskoboinik et al. discloses electroluminescent light sources. A cable-like electroluminescent light source comprises at least two electrodes mutually disposed in such a way as to create between them an electric field when a voltage is applied to them; at least one type of pulverulent electroluminophor dispersed in a dielectric binder and disposed in such proximity to the electrodes as to be effectively excited by the electric fields when created and to emit light of a specific color, and a transparent polymer sheath encasing the electrodes and the electroluminophor.
U.S. Pat. No. 6,400,093 to Baumberg et al. discloses a flexible electro-luminescent light source with active protection from moisture. The substantially flexible, electro-luminescent light source comprises an electrode assembly, dielectric and electro-luminescent layers, with one outer, substantially flexible layer formed of insulating transparent material. The light source is provided with a heating element, and a power supply unit coupled to the electrodes' assembly and to the heating element. The power supply unit selectively operates the electrodes' assembly and the heating element, such as to heat the vicinity of the electrodes' assembly thereby maintaining desired temperature conditions in the vicinity of the light source and thereinside.
Notwithstanding the efforts of prior art workers to construct pet leashes and pet collars that are illuminated by incident light, there remains a need in the art for a flexible pet leash that provides a significant quantum of reliable bright illumination at night-time hours to provide safety when a pet is being walked. A flexible illuminated pet leash, having a robust construction that withstands tensile and torsion forces attending leash usage, has long been needed in the art. Also needed is a flexible, electroluminescent wire illuminated pet leash capable of maintaining high luminosity when subjected to surface abrasion from frictional forces created by contact of the leash with objects having rough exteriors, such as the ground, flooring, posts, trees and the like.
SUMMARY OF THE INVENTION
The present invention provides a flexible pet leash that has an electroluminescent wire, is powered by a portable power supply, and emits a significant quantum of light. The electroluminescent wire is commercially available in several diameters and typically has a diameter of 3.2 mm or 5 mm. The electroluminescent wire is protected from moisture by two coaxial polymeric sleeves. The electroluminescent wire is extremely flexible and can be easily bent to a diameter greater than 5 times the diameter of the wire. The maximum twisting angle is typically 30 degrees per yard of the electroluminescent wire. As a result of this flexure and bending capability, the electroluminescent wire can be spirally wound on the outer perimeter of a flexible braided leash, which may be reflective for added visibility.
The electroluminescent wire illuminated pet leash has a flexible central cylindrical core rope of braided nylon or polypropylene fibers capable of sustaining tensile and torsional forces developed by substantial leash loads. Optionally, in a second embodiment, this braided rope may have cylindrically braided reflective sleeve produced by braiding three or more narrow width reflective strips as disclosed in my copending provisional application bearing, filed of even date herewith, the disclosure of which is incorporated in its entirety by reference thereto. The electroluminescent wire is looped, and preferably spirally wound, around the flexible braided central rope core or in a second embodiment around the cylindrically braided reflective sleeve that covers the flexible cylindrical central core rope to form a continuous lighting wire. One end of the wire is stripped to expose the two copper leads and is soldered to corresponding terminals in the portable power supply that is attached near the handle of the leash. The soldered ends are completely sealed by shrink tubing to prevent moisture damage to the electrophosphoric dielectric within the electroluminescent wire. The power supplied may be operated continuously or turned on and off by a timing circuit to create a blinking effect at a selected blinking rate of the electroluminescent illumination. The electroluminescent wire that is spirally wound may be attached in several places to the flexible braided central rope core, or to the cylindrical braided reflective sleeve, using a polymeric glue or clamp. This attachment prevents the unraveling of the spirally wound electroluminescent wire when the leash is twisted or bent. The electroluminescent wire may be spirally wound around only the central portion of the leash, or may also include spiral winding around the handle. Alternatively the wire can be spirally wound or looped around the handle and a pet collar. The attachment of the pet leash to the pet may comprise a choke collar, electroluminescent wire illuminated choke collar, or a simple clasp connecting to a pet collar that is not illuminated. The electroluminescent wire may be incorporated in a transparent flexible polymeric tube with the end of polymeric tube furthest from the power supply being sealed so as to protect the electroluminescent wire from moisture. This additional transparent polymeric tube provides improved abrasion resistance to the leash and limits damage caused by dragging the leash on the ground while walking a pet.
Optionally a second set of electroluminescent wires may be connected to the power supply and wrapped around the handle of the leash, thereby illuminating the pet owner's hand. In a similar manner, the electroluminescent wire may encircle the portion of the leash that encircles the pet collar illuminating the pet's neck. This illumination method has significant safety advantages, since an oncoming driver during night time hours can easily locate the pet owner, the pet and the leash. The power supply may illuminate the electroluminescent wire surrounding the pet leash and that surrounding the pet owner's hand at different blinking rates for easy identification.
The use of a cylindrically braided reflective sleeve surrounding flexible braided central rope core provides additional illumination of the pet owner, the pet leash, and the collar of the pet. The reflective portion of the cylindrically braided reflective sleeve has bonded retroreflective elements, such as a corner cube retroreflectors or a microsphere retroreflectors, placed over a reflective sheet causing the incident light to be reflected right back to the source. This provides additional light indication in addition to that provided by the electroluminescent wire. While the electroluminescent wire provides illumination at all times when the wire is energized by the battery power, the cylindrically braided reflective sleeve reflects light only when a light, such as a car headlamp, is present. The resultant reflection is only in the direction of the incident headlamp light, while the light emitting electroluminescent wire emanates light in all directions. Advantageously, in all directions other than the direction of incident headlamp light, only the illuminating light produced by the electroluminescent wire is observed.
BRIEF DESCRIPTION OF THE DRAWING
The invention will be more fully understood and further advantages will become apparent when reference is had to the following detailed description of the preferred embodiments of the invention and the accompanying drawing, in which:
FIG. 1 is a diagram of a wound electroluminescent wire illuminating pet leash showing a leash with a battery powered electroluminescent wire wound around a reflective cylindrical braided sleeve which, in turn, surrounds a central core, and thereby forms an illuminated leash handle, illuminated pet leash central section, and illuminated choke collar section; and
FIG. 2 is a magnified sectional of the wound electroluminescent wire illuminating pet leash of FIG. 1 , illustrating the reflective cylindrical braided sleeve of narrow width strips surrounding the central core.
DETAILED DESCRIPTION OF THE INVENTION
The present invention provides a spirally wound electroluminescent wire illuminated pet leash that is flexible, twistable and especially suited for use during dusk or nighttime hours while walking with a pet. Advantageously, leashes constructed in accordance with the invention improve the safety of the pet as well as the pet's owner when walking in dimly lit environments where approaching vehicles are encountered. An integrally formed handle is located on the proximal end of the leash with a power supply attached thereto for driving the illumination of the electroluminescent wire. The power supply may provide continuous voltage to produce continuous illumination or an interrupted timed voltage to produce blinking illumination. The blinking rate may be optionally adjustable by the user.
Unlike other electroluminescent strips, which cannot be readily bent or twisted without destroying the device, the electroluminescent wire of the subject invention can be bent to a diameter greater than 5 times the wire diameter or tolerate a twist of 30 degrees per yard of the electroluminescent wire. Typical diameter of the electroluminescent wire is 3.2 mm or 5 mm, thus accommodating sharp bends. These flexibility features permit the electroluminescent wire to be successfully spirally wound around a flexible central cylindrical rope core of braided nylon or polypropylene fibers. This spiral winding has the advantage that if the flexible central rope braid core is twisted or flexed, the spiral winding accommodates this movement without excessively stressing the electroluminescent wire. The electroluminescent wire may be attached to the flexible central cylindrical rope core at separated locations using polymeric glue or clamps to prevent the unraveling of the spirally wound electroluminescent wire. The electroluminescent wire may be wound around the handle and the pet collar to illuminate the hand holding the leash and the neck of the pet. The electroluminescent wire may be wound around the handle, the central pet leash section, and the pet collar to illuminate the hand holding the leash, the center section of the leash, and the neck of the pet, respectively. The portion of the electroluminescent wire wound around the handle may be powered by the same or a second power source allowing it to blink at a different rate than that of the main pet leash providing a higher level of detectability. In a similar manner, the pet collar may be powered to blink at a different rate.
The flexible central cylindrical braided core rope may optionally be provided with a cylindrically braided reflective sleeve. The cylindrically braided reflective sleeve is created by using a cylindrical braiding process with a shallow braid angle to surround substantially the entire exterior surface of the central cylindrical braided core rope using three or more narrow width reflective strips. The narrow width reflective strips are fabricated from narrow width strips that are braided with nylon or polypropylene fibers to which a reflective flexible sheet with bonded retroreflectors is thermally fused using polyvinyl chloride or polyvinyl acetate glue. The retroreflectors may be corner cube reflectors or microsphere reflectors placed over a reflective sheet. The electroluminescent wire is spirally wound around the cylindrically braided reflective sleeve. The electroluminescent wire may be attached to the cylindrically braided reflective sleeve at separated locations using polymeric glue or clamps to prevent the unraveling of the spirally wound electroluminescent wire. The electroluminescent wire may be also wound around the handle and the pet collar to illuminate the hand holding the leash and the neck of the pet. The portion of the electroluminescent wire wound around the handle may be powered by the same or a second power source allowing it to blink at a different rate than that of the main pet leash providing a higher level of detectability. In a similar manner, the pet collar may be powered to blink at a different rate. This cylindrically braided reflective sleeve underneath the electroluminescent wire reflects any incoming light back to its source over a large range of incidence angles. This feature provides an additional margin of safety to the pet owner and the pet while walking the pet during nighttime hours as compared to that provided by electroluminescent wire illumination solely.
The electroluminescent wire is made from a copper wire, which is surrounded by an electophosphoric dielectric material, such as doped zinc sulfide, and a second set of electrodes are placed on the outer surface of the dielectric. Since the dielectric medium is susceptible to moisture damage, two layers of polymeric coaxial tubes are provided to encase the electroluminescent wire. The wire is sold in long continuous lengths by LyTec and is manufactured by ELAM Electroluminescent Industries Ltd. (Jerusalem, Ill.). A required length of the electroluminescent wire is cut and one end of the wire is stripped to expose the central copper wire and the copper wire surrounding the dielectric. These two wires are attached to corresponding two terminals in the power supply. After the connection is made, the end of the electroluminescence wire is sealed by shrinkable tubing or other means to prevent moisture damage and/or short circuit. The portable power supply accepts batteries of various sizes and converts the DC battery voltage to a AC voltage and transforms it to a AC voltage in the range of 100 to 120. The frequency of the AC voltage can be in the range of 60 Hz to 6 kiloHz. The current levels delivered by the power supply is typically small, less than 100 milliamps, thereby minimizing or eliminating any shock hazard. The voltage requirement to drive an electroluminescent wire is based on the given wire length and wire diameter. Generally, longer wire lengths require a higher voltage. Increasing the frequency of the AC voltage increases the brightness level of light delivered by the eletroluminescent wire. Higher frequency also changes the color of illumination produced by the electroluminescent wire. The brightness achievable by the electroluminescent wire is typically in the range of 32,000 to 45,000 candles per square meter and the illumination is distributed uniformly along the external surface of the wire. The electroluminescent wire typically has a lifetime of 25000 hours of continuous use. The electroluminescent wire is available in a variety of colors and wires of different colors can be soldered together in series providing a multicolored pet leash illumination.
The electroluminescent wire may be additionally protected by encapsulating the wire in a transparent polymeric tube with the end that is furthest from the power supply being permanently sealed. This protects the end of the electroluminescent wire from moisture damage. The transparent polymeric tube also provides abrasion resistance and protects the electroluminescent wire when the illuminated pet leash is dragged on the ground during pet walking.
The power supply may be optionally protected from rain by providing soft buttons and plastic film enclosure of the control buttons. The control button include such indicators as an on/off button, a blinking/steady light button, and blinking rate controls.
FIG. 1 is a diagram of the illuminating pet leash at 10 showing the handle section 11 , the central pet leash section 12 , and the choke collar section 13 . A cylindrically braided sleeve, shown at 25 , created from braided narrow width reflective strips, covers each of these sections ( 11 , 12 , and 13 ), providing substantially the entire surface of the leash with omnidirectional reflectivity. The reflective portion of the braided narrow width reflective strip is shown at 18 and the woven portion of the narrow width strip is shown at 19 . The leash completely reflects incident light in the same direction as the light was emanated. Due to the cylindrical shape of the cylindrically braided reflective sleeve 25 some portion of the sleeve is always at normal orientation to the incoming light beam, that is, the direction at which the reflection from the retroreflective elements is the maximized. Retroreflective elements reflect light over a large range of acceptance angles, but the reflection is at a lower intensity. This cylindrical construction effectively reflects the incoming camera flash light as shown in the diagram of FIG. 1 by the extremely bright appearance of the retroreflectors bonded to the flexible polymer comprising the braided narrow width reflective strip and making up the reflective portion 18 in the leash.
An electroluminescent wire is spirally wound around the cylindrically braided sleeve as shown at 15 . In this figure, the handle is also spirally wound with elctroluminescent wire as shown at 16 . A portable power supply box 14 is attached to the handle to provide AC power to the electroluminescent wire. The power supply carries batteries and the control functions indicated as 17 , that may include: control A for turning the electroluminescent wire on or off; control B to turn the blinking function on/off; and control C, a blink rate control. These controls may be repeated as a separate set (not shown) to control the electroluminescent wire spirally wound around the handle. The distal end is shown as a choke collar (optionally the collar may be a non-choke collar) that also has the electroluminescent wire spirally wound around the cylindrically braided sleeve and the leash passes through a mechanical hardware metallic ring 20 of the collar.
FIG. 2 is a magnified sectional view of the wound electroluminescent wire illuminating pet leash of FIG. 1 , illustrating the reflective cylindrical braided sleeve of narrow width strips surrounding the central core, shown generally at 30 . The cylindrical reflective braided sleeve 25 surrounds the central core, shown at 31 . The cylindrical reflective braided sleeve 25 is created from braided narrow width reflective strips and covers each of the leash sections ( 11 , 12 , and 13 of FIG. 1 ), providing substantially the entire surface of the leash with omnidirectional reflectivity. The reflective portion of the braided narrow width reflective strip is shown at 18 and the woven portion of the narrow width strip is shown at 19 . The electroluminescent wire 15 is spirally wound around the cylindrically braided sleeve 25 .
The key features of the illuminated pet leash include, in combination, the features set forth below:
1. a spirally wound electroluminescence wire illuminated pet leash comprised of a flexible central cylindrical rope core of braided nylon or polypropylene fibers capable of sustaining tensile forces developed by pet leash loads; 2. the pet leash having an integrally formed handle and provisions for a choke collar or clasp connection to a conventional (or non-choke) pet collar; 3. an electroluminescent wire spirally wound around the braided central cylindrical rope core illuminating the leash when connected to power supply; 4. the spirally wound electroluminescent wire optionally attached to the central cylindrical rope core at separate locations using a polymeric glue or clamps to prevent unraveling of the electroluminescent wire when the pet leash is twisted; 5. the braided central cylindrical rope core optionally covered substantially with a cylindrically braided reflective sleeve formed by cylindrically braiding narrow width reflective strips of knitted, woven or braided nylon or polypropylene strips which have thermally bonded flexible retrorefletors sheets attached thereto; 6. the spirally wound electroluminescent wire is optionally attached to the cylindrically braided reflective sleeve at separate locations using a polymeric glue or clamps to prevent unraveling of the electroluminescent wire when pet leash is twisted; 7. an electroluminescent wire spirally wound around the cylindrically braided reflective sleeve illuminating the leash to provide omnidirectional illumination when connected to an active power supply; 8. the handle permanently attached to a AC power supply providing voltage for continuous or controlled rate of blinking of electroluminescent wire; 9. the electroluminescent wire being protected from moisture by a transparent polymeric tube with closed distal end that is further from the power supply; 10. the pet leash handle having a spirally wound electroluminescent wire and illuminating continuously or blinking at a rate that is the same or different from that of the main pet leash; 11. the pet choke collar having a spirally wound with electroluminescent wire and illuminating continuously or blinking at a rate that is the same or different from that of the main pet leash; 12. the flexible retroreflector sheet prepared by bonding corner cube geometry retroreflectors to a flexible polymeric sheet using a transparent binder; 13. the flexible retroreflector sheet prepared by bonding microsphere geometry retroreflectors to a metallized reflective flexible polymeric sheet using a transparent binder; 14. the cylindrical reflective braid sleeve covered pet leash substantially reflecting incident light back in the same direction as the incident light, providing a clear indication of the pet leash handle, pet leash central portion and the pet leash collar surrounding the neck, in addition to the illumination provided by the electroluminescent wire; 15. the spirally wound electroluminescence wire illuminated pet leash providing an increased margin of safety for the pet owner and the pet while walking in dimly lit environments, such as parking garages, or inclement weather conditions, where rapidly moving vehicles are encountered.
Having thus described the invention in rather full detail, it will be understood that such detail need not be strictly adhered to, but that additional changes and modifications may suggest themselves to one skilled in the art, all falling within the scope of the invention as defined by the subjoined claims. | A nylon or polypropylene cylindrical central braided rope core is wound with an electroluminescent wire to form a pet leash. The electroluminescent wire is powered by a portable power supply attached to the handle of the pet leash causing illumination of the electroluminescent wire continuously or intermittently at a selected blink rate. Alternatively, the wound electroluminescent wire surrounds a cylindrical braided reflective sleeve that covers the central braided rope. The cylindrical braided reflective sleeve reflects incident light back to its source while the electroluminescent illumination is provided. Reflection and illumination of light are omnidirectional. The braided construction of the central core and reflective sleeve, together with the configuration of the electroluminescent wire, resist tensile, twist and torsional forces, enabling reliable emission of omnidirectional illumination and reflectivity. In combination, the omnidirectional illumination and reflectivity, strength and flexibility provide a higher margin of safety for pets and their owners while walking in dimly lit environments where vehicles are encountered. | 3 |
BACKGROUND OF THE INVENTION
The present invention relates to the rotor spinning of textile yarns and, more particularly, to rotor spinning machines of the type having a plurality of simultaneously operated spinning stations each equipped with a driven spinning rotor, a driven sliver opening roller, and a driven drawing-in roller for feeding sliver to the opening roller, all of which are installed in a housing of the spinning station having an openable lid or cover to provide access to the functional parts.
Conventionally, sliver is fed to the opening rollers at the spinning stations of rotor spinning machines via drawing-in rollers at each station, each drawing-in roller being connected via a worm gear to a common drive shaft extending along the entire spinning machine. Driving of the drawing-in rollers in this manner is known from published, non-examined German Patent Application DE-OS 27 21 386. If the yarn or sliver breaks, and during piecing up operations, the drawing-in roller is disconnected from the drive shaft by actuation of a coupling. Driving all the drawing-in rollers along one side of the spinning machine with a common drive shaft, and the provision of a coupling for each drawing-in roller, requires a considerable engineering expense and does not allow for individualized feeding of the slivers to be adjustably adapted to particular circumstances at the spinning stations.
SUMMARY OF THE INVENTION
It is therefore an object of this invention to provide a structurally simplified embodiment for driving the operational components of a spinning station in a rotor spinning machine. In accordance with the present invention, this objective is attained by connecting each drawing-in roller at each spinning station to its own individual drive which is supported by the cover of the housing of its respective spinning station. Typically, the housing cover at a conventional rotor spinning station is supported in hinged fashion at the front of the spinning station. Thus, this manner of installation to the cover of the spinning station makes the drawing-in roller and its drive directly accessible for maintenance work when the spinning station housing is opened.
Individual drives advantageously economize on couplings and step-up gears. Gears and especially couplings are subject to wear, which can result in loosened connections and slippage causing inaccurate sliver feeding. This has an especially disadvantageous effect when a yarn is being spliced or otherwise pieced up, if the quantity of sliver fed in is uneven. Specifically, any looseness or slippage in the mechanically meshing components of a conventional drive can affect the mechanical coupling between a splicing or piecing-up carriage and the drawing-in roller during a yarn piecing operation and, in turn, cause inaccurate sliver feeding.
According to a further feature of the invention, the individual drive of each drawing-in roller is a stepping motor. Advantageously, stepping motors can be started from any position without slippage. As a general rule, the stepping motor is connected to a control unit, which by digital signal processing of appropriate sensors present at each spinning station is also capable of performing digital control of sliver feeding. This makes it possible to perform individualized feeding of each sliver that is adapted to the particular situation prevailing at the spinning stations.
In accordance with a further aspect of the invention, each opening roller is similarly connected by its drive shaft to the drive shaft of an individual drive, which is also supported by the cover of the housing of its respective spinning station. Under this drive concept, the conventional rigid drive of all the opening rollers on one side of a spinning machine may be replaced by the option of individual drives which, in turn, may be adapted to the particular operating situation at a spinning station.
Under a further feature of the invention, the individual drive of each opening roller is a driven motor, e.g., an electric motor of the type having an outer driven rotor, the opening roller being in the form of a ring of card clothing on the outer circumference of the rotor. Electric motors of this outer rotor type are capable of installation in the component to be driven, making an especially compact design possible which is particularly advantageous in the present invention. The individualized driving of each drawing-in and opening roller of each spinning station is especially advantageous if the spinning rotor is also provided with its own individual drive. With a suitable electronic control, each spinning station then is largely autonomous so that the spinning stations can be assigned different tasks.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic cross-section through a spinning station of a rotor spinning machine in accordance with a preferred embodiment of the present invention;
FIG. 2 is an end view of the spinning station of FIG. 1 with an end panel of the housing cover removed;
FIG. 3 is a cross-section through the housing cover of the spinning station of FIG. 1 taken along line III--III thereof;
FIG. 4 is a schematic cross-section similar to FIG. 1 of another rotor spinning station according to another embodiment of the present invention equipped with an individual drive for the opening roller;
FIG. 5 is another schematic cross-section similar to FIGS. 1 and 4 of another rotor spinning station according to another embodiment of the present invention in which the individual drive of the opening roller is embodied as an electric motor of the type having an outer rotationally driven rotor; and
FIG. 6 is a cross-section through the housing cover of the spinning station of FIG. 5, taken along line III--III thereof.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to the accompanying drawings and initially to FIG. 1, one representative spinning station 1 of a multi-station rotor spinning machine is shown schematically in section with only those features and characteristics contributing to an understanding of the present invention being shown and described.
The functional components of the spinning station 1 are enclosed within a housing 2, which is closed at its front by a cover or lid 3 which is pivotably supported in a hinge 4 on the underside of the housing 2. The main operational components of the spinning station are a spinning rotor 5, whose shaft 6 is supported rotatably for drive purposes on paired support disk bearings, of which only two bearing disks 8a and 8b have been shown as representative. The rotor shaft 6 is supported axially via a ball-type thrust bearing 9. A drive belt 10 engages the shaft 6 of the rotor 5 between the two bearing disks 8a and 8b and extends lengthwise along the entire spinning machine to drive all of the rotors of the spinning stations at one side of the machine. The arrangement of this type of twin-disk bearing for spinning rotors is already known from the prior art, such as the aforementioned DE-OS 27 21 386, and therefore need not be described in further detail herein. The manner of structural support of the rotor and its drive, which have been described earlier, are not essential to the invention. The present invention achieves its advantages equally well with directly supported rotors and especially when there is an individual drive of the rotor.
The rotor 5 rotates in a chamber 11, which communicates via a conduit 12 with a source of negative pressure (not shown), as symbolized by the arrow 13. With the aid of the negative pressure, the fibers for spinning a yarn are aspirated into the interior circumferential groove 14 of the rotor.
In the present exemplary embodiment, the functional elements required for drawing-in of a sliver, opening of the sliver into individualized fibers, feeding the separated fibers to the rotor for spinning into a yarn, and drawing off the spun yarn from the rotor are accommodated in the cover 3 of the housing 2, as shown schematically in the sectional view of FIG. 1. Specifically, a toothed opening roller 15 is rotatably supported with its drive shaft 16 in contact with a belt 17 extending longitudinally through the length of the machine as the common drive mechanism for the opening roller of each spinning station. Located below the opening roller 15 is a debris collector 18, which carries the debris 19, such as slubs, dust, foreign particles and husk residues, combed out of the sliver away to a central collecting point inside the machine by means of negative pressure, represented by the arrow 20, through a conduit 21. Located above the opening roller 15 is a fiber guide conduit 22, through which the opened fibers 23 are directed into the rotor groove 14, where they are spun into a yarn 24. The yarn 24 is removed from the housing 2 of the spinning station 1 via a yarn draw-off navel 25 through a yarn doff tube 26. Drawing off of the yarn 24 is accomplished in the direction of the arrow 28 via a pair of draw-off rollers 27. Downstream of the pair of draw-off rollers, the yarn is delivered to a winding apparatus (not shown) to form a cross-wound bobbin.
Not visible in FIG. 1 is the drawing-in roller, which is disposed adjacent the opening roller 15 and therefore is hidden by it in the view of FIG. 1. FIG. 2 therefore shows an end view of the spinning station of FIG. 1 to illustrate the primary spinning components, with the front panel 29 of the cover 3 broken away as indicated by the sectioned edge. A tubular sliver condenser 30 is mounted to the cover 3 adjacent the drawing-in roller 32 for delivering the sliver 31 through the condenser 30 to the drawing-in roller 32. The drawing-in roller 32 is driven to rotate in the direction of the arrow 33 and a sliver feed table 35 is pivotably mounted adjacent the periphery of the drawing-in roller 32 and biased thereagainst by a spring device 34. The sliver is compressed between the feed table 35 and the drawing-in roller 32 and delivered to the opening roller 15, which is driven to rotate in the direction of the arrow 36. The fibers are combed out of the sliver and thusly separated from one another. These separated fibers 23 are then fed through the fiber guide conduit 22 and into the circumferential groove 14 of the rotor 5, where they are spun into a yarn 24, as already described. The rotor 5 is driven to rotate in the direction of the arrow 37. The yarn 24 is drawn off through the yarn doff tube 26, as described.
The preferred drive mechanism for the drawing-in roller 32 is a stepping motor 39 located coaxially with the drawing-in roller and connected directly to the shaft thereof. Accordingly, as viewed in FIG. 2, the motor drive to the drawing-in roller 32 is hidden by the drawing-in roller 32 itself, but can be seen in the sectional view of FIG. 3 taken through the cover 3 along the lines III--III of FIG. 1.
As will thus be understood, the disposition of the described operational components of the spinning station 1 with the cover 3 makes them readily accessible when the cover 3 is pivoted open about the hinge 4 in the direction of the arrow 38, as can be seen in FIG. 1.
FIG. 3 shows that the individual stepping drive motor 39 is disposed in axial alignment with and behind the drawing-in roller 32. The stepping motor 39 is connected to a control unit (not shown) via electrical leads 40. The drive shaft 41 of the drawing-in roller 32 is connected directly to the drive shaft 42 of the stepping drive motor 39, via a rigid coupling 43, e.g., a flange connection as shown, which serves to make it easier to replace one of the two functional elements. Alternatively, the motor could be affixed directly on the drive shaft of the drawing-in roller.
In the alternative embodiment of FIG. 4, an individual drive motor 50 for the opening roller 15 is also provided instead of the common drive belt 17 shown in FIG. 1. In this case, the drive shaft 48 of the opening roller 15 is connected directly to the drive shaft 49 of the motor 50 via a rigid connection 51, for instance a flange connection. The motor 50 is mounted to a wall portion 52 affixed to the cover 3 and is connected to a control unit (not shown) via an electrical lead 53.
In the further embodiment of FIG. 5, the individual drive for the opening roller 15 is an electrical motor 45 of the type having a stationary central drive unit and a driven exterior rotor coaxially about the stationary drive unit, rather than an output drive shaft per se.
An annular covering of card clothing 15a is attached to the driven rotor of the motor 45 to serve as the opening roller for the sliver 31. The stationary drive unit of the motor 45 is therefore located inside the card clothing 15a and is secured to a wall portion 47a of the cover 3 by fasteners, such as screws 47. The motor 45 is connected to a control unit (not shown) via an electrical lead 46.
FIG. 6 is a sectional view of the spinning station of FIG. 5 with the cover 3 broken away along line III--III as in FIG. 3. As will be seen, in comparison to the embodiment of FIG. 3, the elimination of the drive shaft 16 of the opening roller resulting from use of the rotor-type driven motor 45 provides an advantageously compact design.
The mounting of the described operational components in the cover 3 is accomplished by a modular connection system. That is, each of the condenser 30, the drawing-in roller 32, its drive motor 39, the opening roller 15 with its drive shaft 16 or with the possible individual drive motors 45,50, and the fiber guide conduit 22 are installed in the cover via plug-type or screw connections (not shown) in appropriate manners enabling them to be detached and removed individually, thereby providing easy accessibility and maintenance.
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 embodiments, adaptations, variations, modifications and equivalent arrangements, the present invention being limited only by the claims appended hereto and the equivalents thereof. | In a rotor spinning machine, each spinning station's drawing-in roller is connected directly to its own individual drive supported by the cover of the spinning station housing, which provides a simplified and conveniently accessible alternative to the conventional worm gear driving of the drawing-in rollers of the machine's plural spinning stations from a common drive shaft. | 3 |
FIELD OF THE INVENTION
This invention relates to a covered drinking cup of the type often used by infants and children as a training cup because it safeguards against spills and provides liquid flow through a nipple-like spout. More specifically, this invention relates to covered drinking cups that provide a leak-proof flow of the liquid and venting of the head space as liquid is withdrawn.
BACKGROUND OF THE INVENTION
In the past nursing bottles and cups for dispensing milk and other liquids to infants and children have often been in the form of vented covered containers. For instance, U.S. Pat. No. 2,372,281 to Jordan, which issued on Mar. 27, 1945, has a cover that provides a nipple on one side having flow-regulating means and a vent on the other side also having flow-regulating means. By adjusting the two flow-regulating means, the user can comfortably draw liquid from the nipple. As the liquid is withdrawn, air moves in through the vent to replace the withdrawn liquid and prevent negative pressure build-up which in the extreme can stop liquid flow.
Another covered drinking cup is disclosed in U.S. Pat. No. 2,608,841 to Rice which issued on Sep. 2, 1952. As the venting means, the Rice cup provides a manually adjustable valve which controls the ease with which air is admitted into the cup for venting. It thereby regulates the flow of liquid.
With respect to the admission of air into nursing bottles and the like, check valves have often been used and are disclosed in the U.S. Pat. Nos. 4,401,224 to Alonso which issued on Aug. 30, 1983; 4,545,491 to Bisgaard, et al. which issued on Oct. 8, 1985; 4,723,668 to Cheng which issued on Feb. 9, 1988; and 4,828,126 to Vincinguerra which issued on May 6, 1989.
Other vent means are disclosed in U.S. Pat. No. 4,865,207 to Joyner, et al. which issued on Sept. 12, 1989 in which a fabric hydrophobic filter passes air into the nurser.
U.S. Pat. No. 4,135,513 to Arisland, which issued on Jan. 23, 1979, discloses a drinking nozzle for a nursing bottle which incorporates air venting means, opening a valve when the pressure within the container is substantially less than atmospheric pressure to thereby vent the head space.
U.S. Pat. No. 5,079,013 to Belanger, which issued on Jan. 7, 1992, discloses a dripless liquid feeding/training container in which the cover is provided with two spring-biased check valves. One check valve is a spring biased ball check that permits inward air flow for venting and the other check valve is a spring-biased outlet valve that opens by the sucking action of the infant and springs closed when the sucking action relents. The container is described as “dripless”.
One of the shortcomings of some of the prior art is that the valves involved have metal parts. Further, the number of the parts involved makes such containers difficult to manufacture, assemble and clean. There is, hence, a need for a less complicated structure that eliminates the metal parts, and is readily washable. It is to such a need that the present invention is directed. In a preferred embodiment, the control element has additional means to retainer it in place in the cup even during impact.
SUMMARY OF THE INVENTION
The present invention is a control element for a drinking cup, and the drinking cup in which the cover has a drinking spout at one side and a vent at the other. Tubular elements extend down from under the spout and the vent. The flow control element of elastomeric material is provided having a pair of spaced cavities on one side, each cavity having a floor at the bottom thereof. In assembly, the cavities receive in frictional engagement the lower ends of the tubular elements. This engagement supports the flow control element with the floor of each cavity in sealed relation with respect to its tubular element. Each floor has a passage that is normally closed but opens on the occurrence of a pressure differential on opposite sides of the floor.
In a preferred embodiment, the control element includes a pair of shoulders that assist in maintaining the control element in place even during impact.
BRIEF DESCRIPTION OF THE DRAWINGS
Further objects and features of the present invention will be apparent to those skilled in the art from a study of the following specification and the accompanying drawings, all of which disclose a non-limiting embodiment of the invention. In the drawings:
FIG. 1 is a perspective view of an assembled drinking cup that embodies the invention;
FIG. 2 is an enlarged perspective view of a first embodiment of the flow control element of the invention;
FIG. 3 is a top plan view of the flow control element of FIG. 2;
FIG. 2 is an enlarged fragmentary sectional view taken on the line 4 — 4 of FIG. 1;
FIG. 5 is an enlarged perspective view of a second embodiment of the flow control element of the invention; and
FIG. 6 is an enlarged fragmentary sectional view taken on the line 4 — 4 of FIG. 1 of the flow control element of the second embodiment of FIG. 5 .
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to the drawings and, in particular, FIG. 1, a drinking cup that embodies the invention is generally represented by reference numeral 10 . The drinking cup 10 comprises a cup-shaped container 12 having a cover 14 that may be screwed on to the top of the container by cooperant threads shown in FIG. 4 . The cover 14 comprises a top wall 16 and a depending downward or side wall 18 formed with interior threads that engage exterior threads about the mouth of the container 12 as described.
Just inside the downward wall 18 , the cover 14 may be provided with a short annular wall 20 . Also, an O-ring (not shown) may be disposed in between the annular wall 20 and the side wall 18 of the cover 14 . The O-ring may be compressed to form a liquid sealing joint between the cover 14 and the container 12 .
One side of the top wall 16 is provided with a drinking spout 22 which has dispensing openings 24 at its distal end. Formed unnaturally with the cover 14 and extending downward from the spout 22 inside the cover is an element 26 . In the embodiment shown in FIG. 1, the spout 22 and element 26 are tubular elements, however these elements can be any geometric shape. It is important that the spout 22 and element 26 communicate into liquid tight engagement. Therefore, the spout 22 and element 26 preferably have holes therethrough of the same shape.
At the opposite side of the top wall 16 , the cover 14 is provided with a vent 28 . Formed unnaturally with the cover 14 is a downward element 30 which communicates with the vent 28 . In a preferred embodiment, element 30 is tubular in shape, however it can also be any shape. It is also preferable, that the since the vent 28 and element 30 have air tight communication between each other, that they have holes therethrough of the same shape.
Both elements 26 and 30 terminate downwardly at the same level in downwardly facing openings. In the preferred embodiment, both elements 26 and 30 are tubular or cylindrical. Since element 26 communicates with the spout 22 , while the element 30 communicates with the vent 28 , the diameter of element 26 is preferably larger than the diameter of element 30 . However, it is understood that the diameter of the holes of each element 26 , 30 can be any size and shape depending on the size and shape of the spout 22 and vent 28 , respectively.
As shown in FIG. 2, there is provided a flow control element 40 . It is preferably a single piece of elastomeric material, such as, for example, thermoplastic elastomer, silicone, or a soft rubber. The elastomeric material is resilient and flexible and does not have any separate parts, such as balls and springs. The control element 40 has a pair of spaced cavities 42 , 44 formed in one side. The pair of spaced cavities 42 , 44 are formed near opposite ends 41 of the control element 40 . The cavities 42 , 44 can have any shape, however they should have a shape that complements the shapes of elements 26 , 30 , respectively. Therefore, in a preferred embodiment, cavities 42 , 44 should have a tubular or circular shape. Each cavity 42 , 44 has a one or any number more of ribs 50 , 52 , respectively. In the preferred embodiment, each cavity 42 , 44 has two ribs. These ribs 50 , 52 act to seal the cavity 42 , 44 to the respective element 26 , 30 .
Also, cavity 42 complements element 26 that communicates with spout 22 , and cavity 44 complements element 30 that communicates with vent 28 . Accordingly, in the preferred embodiment, the cavities 42 , 44 are cylindrical. Furthermore, the diameter of cavity 42 is greater than the diameter of cavity 44 due to the difference in the diameters of the spout 22 and the vent 28 . For example, in an embodiment in which the elements 26 , 30 are cylindrical and with conventional, different diameters, cavity 42 has a rib diameter about 0.57 inches and a flat (the area between ribs) diameter about 0.63 inches, whereas cavity 44 has a rib diameter about 0.50 inches and a flat diameter about 0.55 inches.
In the preferred embodiment, the spout 22 is closer to side wall 18 than vent 28 . Accordingly, as shown in FIG. 4, the cavity 42 is closed to edge 41 than cavity 44 is to respective edge 41 . It should be understood, however, that if the relationship of the spout 22 and vent 28 to side wall 18 varies so does the relationship of the cavities 42 , 44 to edge 41 . Accordingly, cavities 42 , 44 can be equidistant from respective edges 41 , or cavity 44 can be closer than cavity 42 to respective edge 41 .
The control element 40 is formed with floors 46 , 48 at the bottom of each cavity 42 , 44 , respectively. As stated above, extending inward from the sides of each cavity 42 , 44 are, in a preferred embodiment, a pair of spaced horizontal inward circumferential ribs 50 , 52 , respectively. In particular, cavity 44 has a pair of ribs 50 , and cavity 44 has a pair of ribs 52 . As also stated above, each cavity may have any number of ribs. The ribs 50 , 52 secure the control element 40 onto elements 26 , 30 , respectively, by frictional engaging the exterior walls of the elements. It is preferred that the lowermost one of the pair of ribs 50 in cavity 46 not contact floor 46 , and likewise the lowermost one of the pair of ribs 52 in cavity 44 not contact floor 48 . By this feature, the least amount of tension is placed on the control element 40 during use. By minimizing this tension, the sealing characteristics of the slit is optimized.
Referring to FIGS. 3 and 4, the floors 46 , 48 are formed with slits 54 , 56 , respectively. The slits 54 , 56 can have many forms, two of which are “Y”- or “X”-shaped slits for the passage of fluid. Preferably, one slit 54 , 56 in each floor 46 , 48 , respectively, is sufficient to facilitate the passage of liquid in element 26 and the passage of air in element 30 . However, multiple slits in each floor may be designed to provide the same function.
In the assembly shown in FIG. 4, the two cavities 42 , 44 are aligned with the two, preferably tubular, elements 26 , 30 and the control element 40 is raised. The elastomeric nature of the control element 40 is sufficient to flex as the control element is effected. The control element 40 is then shoved “home” on each element 26 , 30 so that the lower ends of the elements abut against the floors 46 , 48 , respectively and effect therewith a snug contact that amounts to a seal, especially in view of ribs 50 , 52 frictional contact on elements 26 , 30 , respectively. Slight imprecision in the dimensions of the cavities 42 , 44 or of the control element 40 can be tolerated due to the soft resilient nature of the control element and, perhaps, the ribs 50 , 52 .
After the container 12 is filled with liquid, the cover 14 is screwed onto the container. As the infant tilts the container and sucks liquid through the openings 24 , the slits 54 yield and part in the center of the slits. When the sucking pressure relents, the resilience of the cavity 42 causes the slit 54 to close once more so that were the cup 10 to be tipped over or to fall on the floor, no appreciable liquid would pass out the openings 24 .
As the liquid is removed as by sucking on spout 22 , a negative pressure builds up in the head space above the liquid. To avoid this pressure—pressure differential across the floor 48 —becoming too great, the slits 56 yield, the centers moving downward to permit passage of atmosphere through the opening 28 and through the slits. When the pressure differential is substantially returned to zero, the resilience of the control element 40 causes the slits to close so that should an upset occur, no liquid could escape outwardly therefrom through vent opening 28 , and a leak through that route is avoided.
Referring to the second embodiment of FIGS. 5 and 6, the same elements recited above will bear the same reference numeral except with a prime. As shown in FIG. 5, the control element 40 ′ includes a pair of shoulders 62 , 64 adjacent the opposite ends or edges 41 ′ of the control element, and extending in a direction opposite the opening of each cavity 42 ′, 44 ′. Each shoulder 62 , 64 has a surface configuration analogous to that of the ends 41 ′.
As shown in FIG. 6, in the most preferred embodiment, each shoulder 62 , 64 has a portion 66 that may be either straight or chamfered and an inwardly chamfered or angled portion 67 . The chamfered portion 67 is adapted to mate with the inside surface of the side walls 18 ′ of the container in order to prevent the control element from disengaging elements 26 ′ and 30 ′. In a preferred embodiment, the chamfered portion 67 may be at angle of about seventy-seven degrees with the vertical, straight portion.
In the most preferred embodiment shown in FIG. 6, each shoulder 62 , 64 has a vertical extant of the valve and shoulder about 0.54 inches. The vertical extant of each shoulder 62 , 64 is affected by its distance from edge 41 , which as stated above is dictated by the position of spout 22 ′ and vent 28 ′ from the side wall 18 ′ of the container.
It is understood that the shoulders 62 , 64 can consist solely of a straight portion, an outwardly angled, an inwardly angled portion or any combination of same depending on the angle of the walls of the container 12 . In addition, the shoulders 62 , 64 can have any shape. The sole criteria is that is mates with the inside of the side walls 18 ′ of the container to help prevent the control element 40 from disengaging the elements 26 ′, 30 ′. The pressure for the control element 40 ′ to dislodge particularly occurs when the control element 40 ′ is forced away from the spout and vent of the cover upon impact.
In either embodiments, after use, the cup 10 of the invention may be readily disassembled. Referring to FIG. 1, the cover 14 may be removed and the control element 40 simply withdrawn off the elements 26 , 30 . All of the components are readily washable.
It will be seen that the invention provides a training cup of three simple parts which is inexpensively and readily made and assembled and works effectively to avoid spills and drips.
The invention described here may take a number of forms. It is not limited to the embodiment disclosed but is of a scope defined by the following claim language which may be broadened by an extension of the right of exclude others from making, using or selling the invention as is appropriate under the doctrine of equivalents. | A drinking cup has a cover which is formed with a drinking spout at one side and a vent at the other. Elements extend down from under the spout and the vent. A flow control element is provided and made of elastomeric material having a pair of spaced cavities on one side, each cavity having a floor at the bottom thereof. The cavities receive in frictional engagement respectively the lower ends of the elements. This engagement supports the flow control element with the floor of each cavity in sealed relation to its element. Each floor has a passage which is normally closed but opens on the occurrence of a pressure differential on opposite sides of the floor. | 0 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to electromagnetic actuators for a control valve of a fuel injector for internal combustion engines.
2. Background Art
Co-pending U.S. patent application Ser. No. 10/197,317, filed Jul. 16, 2002, entitled “Electromagnetic Actuator and Stator Design in a Fuel Injector Assembly” now U.S. Pat. No. 6,565,020, discloses an injector assembly for an internal combustion engine wherein a plunger body, a valve body and nozzle assembly are arranged in a linear, stacked relationship. The valve body encloses a magnetic core. The magnetic core is surrounded by windings that are energized to create a magnetic circuit, which creates a magnetic force that draws an armature connected to a control valve towards the magnetic core to close the control valve. The magnetic core has a generally E-shaped cross section having a central inner portion and outer portions. The magnetic circuit comprises the central portion of the magnetic core, the armature, and the outer portions of the magnetic core.
The co-pending patent application and U.S. Pat. No. 6,565,020 are owned by the assignee of the present invention.
The separate magnetic core components of the design of the co-pending patent application are assembled with the valve body prior to assembling the control valve and valve actuator. It would simplify manufacture of the fuel injector if the magnetic core could be made integral with the valve body. Such a core design also would be more economical to manufacture than a magnetic core with separate components.
SUMMARY OF THE INVENTION
The electromagnetic actuator of the invention is adapted for use with a control valve module described in the co-pending application identified above.
The actuator of the invention comprises a modular valve body having an opening therein and a coaxial bore extending at least partially through the valve body. A control valve, having an armature attached thereto, is inserted into the bore in the valve body. A magnetic core, encircled by windings, is inserted into the opening in the valve body. A valve spring biases the armature away from the magnetic core, and a retainer ring holds the windings and the magnetic core in the opening in the modular valve body. The windings, when energized, produce a magnetic circuit that includes the modular valve body, magnetic core, armature, and retainer ring to attract the armature towards the magnetic core.
The valve body of the actuator of the invention comprises an integral part of the magnetic circuit, unlike the magnetic core of generally E-shaped cross-section in the design disclosed in the co-pending application. The invention simplifies the manufacturing and assembly process and reduces the cost of the fuel injector. If the inner portion of the core is formed by laminated windings, the magnetic performance of the actuator is enhanced.
In accordance with one embodiment of the invention, both the inner and outer magnetic core portions are made as a part of the valve body, which eliminates the need for a separate inner core portion. The core windings are held in place by a retainer ring. In accordance with another embodiment of the invention, the retainer ring can be eliminated if the armature is sized to overlie the core windings. Thus, the windings can serve the secondary function of a retainer. Such a design would be useful if the resulting increased mass of the armature is not detrimental to the effective performance of the injector.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a cross-sectional view showing the overall assembly of an injector that incorporates the electromagnetic actuator of the invention;
FIG. 2 is an enlarged partial cross-sectional view showing the stator design and electrical connector of the invention;
FIG. 3 is a cross-sectional view of one embodiment of the valve body having an integral magnetic core;
FIG. 4 is a cross-sectional view of another embodiment of the valve body having an integral magnetic core wherein a retainer ring for the windings is eliminated; and
FIG. 5 is a perspective view of a round laminated core.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to the drawings, an injector assembly, including the actuator of the present invention, includes a relatively small pump body 64 . A central pumping cylinder 66 in body 64 receives plunger 68 . A cam follower assembly 70 includes a follower sleeve 72 and a spring shoulder element 74 . The follower assembly 70 is connected to the outer end of plunger 68 . The cylinder 66 and plunger 68 define a high-pressure cavity 78 . The plunger is urged normally to an outward position by plunger spring 80 , which engages the shoulder element 74 at the outer end of the plunger. The inner end of the spring is seated on a spring seat 81 of the pump body 64 .
The cam follower assembly 70 is engageable with a surface 71 of an actuator assembly shown at 73 , which is driven by engine camshaft 75 in known fashion. The stroking of the piston creates pumping pressure in chamber 78 , which is distributed through an internal passage 82 formed in the lower end of the pump body 64 . This passage communicates with the high-pressure passage 84 formed in valve body 86 . The opposite end of the passage 84 communicates with high-pressure passage 88 in a spring cage 106 for needle valve spring 92 .
The spring 92 engages a spring seat 94 , which is in contact with the end 96 of a needle valve 98 received in a nozzle element 100 . The needle valve 98 has a large diameter portion and a smaller diameter portion, which define a differential area 103 in communication with high-pressure fuel in passage 88 . The end of the needle valve 98 is tapered, as shown at 102 , the tapered end registering with a nozzle orifice 104 through which fuel is injected into the combustion chamber of the engine with which the injector is used.
When the plunger 68 is stroked, pressure is developed in passage 88 , which acts on the differential area of the needle valve and retracts the needle valve against the opposing force of needle valve spring 92 , thereby allowing high-pressure fuel to be injected through the nozzle orifice. Spring 92 , located in the spring cage 106 , is situated in engagement with the end of the pocket in the spring cage occupied by spring 92 . A spacer 110 , located at the lower end of the spring cage 106 , positions the spring cage with respect to the nozzle element 100 . A locator pin can be used, as shown in FIG. 1, to provide correct angular disposition of the spacer 110 with respect to the spring cage 106 .
A control valve 112 is located in a cylindrical valve chamber 114 . A high-pressure groove 116 surrounding the valve 112 is in communication with high-pressure passage 84 . When the valve is positioned as shown in FIG. 2, the valve 112 will block communication between high-pressure passage 84 and low-pressure passage or spill bore 118 , which extends to low-pressure port 120 in the nozzle nut 122 .
The nozzle nut 122 extends over the valve module 86 . It is threadably connected at 124 to the lower end of the pump body 64 .
The connection between passage 84 and groove 116 can be formed by a cross-passage drilled through the valve body 86 . One end of the cross-passage is blocked by a pin or plug 126 .
The end of control valve 112 engages a control valve spring 128 located in valve body 86 . This spring tends to open the valve and to establish communication between high-pressure passage 84 and low-pressure passage 118 , thereby decreasing the pressure acting on the nozzle valve element.
Valve 112 carries an armature 132 , which is drawn toward stator 130 when the windings of the stator are energized, thereby shifting the valve 112 to a closed position and allowing the plunger 68 to develop a pressure pulse that actuates the nozzle valve element.
The stator 130 is located in a cylindrical opening 134 in the valve body 86 . The valve 112 extends through the central opening and valve chamber 114 in the stator assembly. The windings of the stator assembly extend to an electrical terminal 136 , which in turn is connected to an electrical connector assembly 138 secured to the pump body 64 . This establishes an electrical connection between a wiring harness for an engine controller (not shown) and the stator windings.
A low-pressure passage 140 is formed in the pump body 64 . This communicates with a low-pressure region 142 at the stator assembly and with a low-pressure region 144 , which surrounds the valve body 86 . Fluid that leaks past the plunger 68 during the pumping stroke is drained back through the low-pressure passage 140 to the low-pressure return port 120 .
The interface of the upper end of the spring cage 106 and the lower end of the valve body 86 is shown at 146 . The mating surfaces at the interface 146 are precisely machined to provide flatness that will establish high-pressure fluid communication between passage 88 and passage 84 . The pressure in spring cage 106 , however, is at the same pressure that exists in port 120 . This is due to the balance pressure port 148 , seen in FIGS. 2, 3 and 4 , whereby the chamber for spring 128 communicates with the low-pressure region surrounding the valve body 86 .
The interface between the upper end of the valve body 86 and the lower end of the pump body 64 is shown in FIG. 2 . The upper surface of the valve body 86 and the lower surface of the pump body 64 are precisely machined to establish high-pressure fluid distribution from passage 82 to passage 84 . The seal established by the mating precision machined surfaces at each end of the valve module 86 eliminates the need for providing fluid seals, such as O-rings.
The assembly of the pump body 64 , the valve module 86 , the spring cage 106 and the nozzle element 100 are held in stacked, assembled relationship as the nozzle nut 122 is tightened at the threaded connection 124 , seen in FIG. 1 . The module, the spring cage and the nozzle element can be disassembled readily merely by disengaging the threaded connection at 124 , which facilitates servicing and replacement of the elements of the assembly.
The valve body contains a cut-out portion or opening 152 into which is fitted a bobbin 154 containing a plurality of windings 133 . The windings 133 are electrically connected to the conductor 136 , which in turn is electrically connected to connector assembly 138 , as mentioned above. This provides electrical communication of the windings with the engine control system (not shown) for controlling the operation of the fuel injector. A magnetic inner core portion 137 is also inserted into the cut-out portion 152 . A retainer 135 is inserted into the cut-out portion 152 to retain the bobbin 154 .
In the design of the co-pending patent application identified above, the magnetic circuit comprises a magnetic core of generally E-shaped cross-section. The valve body is not included as part of the magnetic circuit. However, in this invention, the valve body 86 is part of the magnetic circuit M, as shown in FIGS. 2, 3 and 4 . This design is advantageous because it eliminates separate magnetic core components and allows, as in the case of the design of FIG. 2, a larger diameter wire and more turns to be designed into a same-size valve body compared to a conventional E-section core.
The valve spring 128 normally biases the control valve 112 to an open valve position. To close the control valve 112 , the engine controller energizes the windings 133 , which produces a magnetic flux circuit that flows through the magnetic core portion 137 , the valve body 86 , the retainer 135 , and the armature 132 . The magnetic circuit M creates a magnetic force that draws the armature 132 towards the stator 130 .
In another embodiment illustrated in FIG. 3, the magnetic core portion 137 is an integral part of valve module 86 thereby further reducing the number of components. The bobbin 154 containing the windings 133 is inserted into opening 134 in valve body 86 . In this case, the magnetic circuit M includes the valve module 86 , the retainer 135 , and the armature 132 . This eliminates the need for a separate magnetic core.
In yet another embodiment illustrated in FIG. 4, the separate retainer ring shown in the previous figures has been eliminated. A press fit maintains the bobbin 154 in place in the control valve body 86 . The modified armature 132 can be used with a separate magnetic core portion 137 (as shown in FIG. 2) or with an integral magnetic core (as shown in FIG. 3) producing magnetic circuits M that travel through the valve body 86 , magnetic core portion 137 , and armature 132 or the valve body 86 and armature 132 , respectively.
FIG. 5 illustrates another example of a magnetic core that can be used with the present invention. The magnetic core portion 137 shown in FIG. 5 comprises a laminated, wound, flat strip, preferably of high magnetic saturation metal. The laminated core minimizes the formation of eddy currents that are detrimental to the performance of the fuel injector. The eddy currents slow down the demagnetization process. Natural oxides that form on the metal strip reduce the formation of eddy currents by electrically isolating the rolled strip windings. Further eddy current reduction can be obtained by coating the strip with a nonconductive coating prior to rolling the metal strip.
Unlike the injector design of the co-pending patent application identified above, the magnetic core of each of the embodiments of the present invention does not have an outer circuit to conduct the magnetic flux. The valve body provides the outer path for the magnetic flux flow. The core diameter can be slightly increased to compensate for the reduction in the pole face area. In the case of the design of FIG. 3, the retainer ring shown at 135 completes the magnetic circuit between the armature and the valve body. Unlike the design of the co-pending patent application, the valve body and the core of the design of FIGS. 3 and 4 are not separate components since the valve body is part of the magnetic circuit. This eliminates parts from the overall assembly and simplifies assembly procedure while reducing cost further. Integration of the outer core portions with the valve body makes it possible to increase the volume of the magnetic wire windings. As previously mentioned, the design of the invention has the further advantage of enabling the designer to use larger diameter wire and more turns with the available module size. Since magnetic forces are proportional to the product of the amperage and the number of turns in an unsaturated state, the design of the present invention provides a higher force with lower resistance.
In the embodiment of the invention shown in FIGS. 1 and 2, the valve body, which is magnetized, is made from a high strength material, typically a high carbon steel, that provides fatigue resistance to high stress resulting from high injection pressure. High injection pressure is required for diesel fuel injection. The core portion 137 of FIG. 2 is made of magnetized material of high coercivity and high permeability and is retained in place against the adjacent surface of the valve body 86 by mechanical and magnetic forces. When the windings 133 are not energized, the residual magnetism of the valve body due to the high coercivity of the valve body retains the core in contact with the valve body. This complements the retention forces of the retainer ring and the bobbin, the latter being press-fitted in opening 134 .
When the coils are energized, the air gap at 131 between the core and the valve body, seen in FIG. 2, is smaller than the air gap 139 between the armature and the core. Because of the larger air gap at 139 , the magnetic forces will pull the armature toward the core. The force on core portion 137 at air gap 139 always will be less than the force at air gap 131 between the core and the valve body. Thus, a contact force between the core portion 137 and the valve body always will retain the core portion 137 securely in place when the magnetic circuit is either energized or non-energized.
The core and the bobbin can be encapsulated with a polymer, if that is desired, to form a more permanent assembly. This configuration may be desirable in some instances when high forces due to pressure or vibration tend to cause the magnetic core to move.
In the embodiment of FIG. 2, the magnetic circuit is completed as the magnetic flux travels through the valve body, through the retaining ring and through the armature. The armature and the retaining ring are soft magnetic alloys, which maximizes the magnetic performance. The magnetic force that closes the control valve is created at the air gap 139 between the armature and the core. A second air gap exists between the inner surface of the retaining ring and the outer surface of the armature. This air gap is designed with a minimum clearance so as to minimize the energy losses as the magnetic flux traverses the air gap. This is true also of the air gap between the retainer ring 135 and armature of FIG. 3 .
The retaining ring 135 has a dual function of conducting magnetic flux and retaining the bobbin. This is desirable because more volume within the space limitations of the design is then made available for the magnetic windings rather than having an additional part to accomplish the retention function. Furthermore, in the case of the designs of FIGS. 1, 2 and 3 , the mass of the armature is reduced because of the presence of the retaining ring 135 . This improves the dynamic behavior of the design since the reduced mass makes it possible to improve the valve response to commands issued by the engine control system. In those instances, when the reciprocating mass of the armature is less important and the reduction of the number of components of the design is more critical, the armature 132 may be made as indicated in FIG. 4 . This concept can be used also, of course, in the case of the embodiments of the invention illustrated in FIGS. 1 and 2.
Although embodiments of the invention have been disclosed, it will be apparent to persons skilled in the art that modifications may be made without departing from the scope of the invention. All such modifications and equivalents thereof are intended to be covered by the following claims. | An electromagnetic actuator for a fluid pressure control valve in a fuel injector for an internal combustion engine is disclosed. The actuator comprises a valve body having an opening therein and a bore extending at least partially therethrough. A control valve having an armature attached thereto is inserted into the bore in the valve body. A magnetic core, encircled by windings, is located in the opening in the valve body. A valve spring biases the armature away from the magnetic core. The windings, when energized, produce a magnetic circuit that includes the valve body, magnetic core, armature, and retainer ring to attract the armature towards the magnetic core. | 5 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the invention
[0002] The present invention relates to a dish washer, particularly, to a dish washer having a sterilizing apparatus to sterilize the bacteria on the dishes.
[0003] 2. Description of the related Art
[0004] In general, a dish washer is a home appliance that the food remnants on the dishes are washed by wash liquid which is spouted out of an injection nozzle with a high pressure.
[0005] Particularly, a dish washer includes a tub forming a washing chamber and a sump installed under the tub for storing washing liquid. The washing liquid is pushed to an injection nozzle by a washing pump installed in the sump, and then injected at a high pressure through an injection aperture formed in an end of an injection nozzle. The injected washing liquid removes dirt such as remaining food from dishes by colliding with the dishes, the removed dirt drops to a bottom of the tub.
[0006] The dish washer further includes a sterilizing apparatus for sterilizing the dishes. The sterilizing apparatus is installed on the aspect part or the rear part of the tub. The ultraviolet rays are used as a means for sterilizing the dishes.
[0007] However, if a sterilizing apparatus is installed on the aspect part or the rear part of the tub, it is onerous for users, because users have to go into the tub or disassemble the tub when a sterilizing apparatus gets out of order.
SUMMARY OF THE INVENTION
[0008] The present invention is proposed to solve the above-mentioned problems. Therefore, an object of the present invention is to provide a dish washer that the sterilizing power toward the inner part of a tub and the dishes is improved as installing the sterilizing apparatus on the inner part of a dish washer.
[0009] Another object of the present invention is to provide a dish washer which as a sterilizing apparatus is installed on a door, the users can replace and repair easily.
[0010] A dish washer according to the present invention comprises: a tub for holding dishes and opened an one end thereof; a door for selectively sealing the opened end of the tub, and have a depressed part with a little of depth on an inner side; a sterilizing apparatus which is installed on the door, wherein the sterilizing apparatus includes an ultraviolet rays generating section which occurs the ultraviolet rays, a reflection member which is installed on the depressed part, and reflects the ultraviolet rays which is occurred on an ultraviolet rays generating section into the inner side of the tub, and a cover member which prevents the influx of the washing liquid into an ultraviolet rays generating section.
[0011] A dish washer according to another aspect of the present invention comprises: a tub forming a sterilizing space that the dishes are sterilized; a door for selectively sealing the sterilizing space; a sterilizing apparatus provided on the inner side of the door; and a power supply section which supplies a power to the sterilizing apparatus, wherein the sterilizing apparatus includes an ultraviolet rays generating section which emits the ultraviolet rays into the sterilizing space, a reflection member which is formed on the inner side of the door as depressed with a little of depth, reflects the ultraviolet rays occurred on an ultraviolet rays generating section toward the sterilizing space, and a cover member united on the inner side of the door.
[0012] A dish washer according to another aspect of the present invention comprises: a sterilizing apparatus including an ultraviolet rays generating section, a supporting section which supports an ultraviolet generating section, a reflection member which reflects the ultraviolet rays occurred on the ultraviolet rays generating section, and a cover member which covers an ultraviolet rays generating section; a door that a place that the reflection member is placed is formed as depressed with a little of depth and the cover member is joined; and a tub which is able to be open by a door.
[0013] According to the present invention, it is effective that the sterilizing power of the inner part of a tub and dishes is increased as a sterilizing apparatus is placed on a door of a dish washer.
[0014] Further, according to the installing of a sterilizing apparatus on a door and be capable of being stuck or being separated of a cover member, an ultra violet rays generating section is able to be fixed or replaced easily according to a user's necessity or on the breaking down.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this application, illustrate embodiment(s) of the invention and together with the description serve to explain the principle of the invention. In the drawings:
[0016] FIG. 1 is a perspective view roughly showing a dish washer having a sterilizing apparatus according to the present invention.
[0017] FIG. 2 is a cross-sectional view roughly showing a dish washer having a sterilizing apparatus.
[0018] FIG. 3 is a magnified view of the part A of FIG. 2 .
DETAILED DESCRIPTION OF THE INVENTION
[0019] Reference will now be made in detail to the preferred embodiments that are concrete of the present invention, examples of which are illustrated in the accompanying drawings.
[0020] FIG. 1 is a perspective view roughly showing a dish washer having a sterilizing apparatus according to the present invention, and FIG. 2 is a cross-sectional view roughly showing a dish washer having a sterilizing apparatus.
[0021] Referring to FIG. 1 and 2 , a dish washer 100 having a sterilizing apparatus according to the present invention comprises a case 101 forming the external shape, a tub 110 forming a washing chamber as placed on the inner side of the case 101 , a door 111 opening and closing the washing chamber as formed on the front surface of the tub 110 , and a sump 170 storing the washing liquid as formed on the low center part of the tub 110 .
[0022] The dish washer 100 further comprises a washing pump 180 which is connected with the sump 170 , and pumping the washing liquid which is stored on the sump 170 with a high pressure, and a washing motor 190 which is installed on the washing pump 180 , and operating the washing pump 180 .
[0023] The dish washer 100 further comprises a water guide 140 to be a flowing course for the washing liquid which is pumped on the washing pump 180 , a lower part nozzle 160 united with the upper side of the sump 170 , spouts the washing liquid out toward the upper part as formed on the low side of the washing chamber, an upper part nozzle 150 placed on the center part of the washing chamber as united perpendicular direction on the water guide 140 , a top nozzle 155 provided on the end of a side of the water guide 140 , and spouts the washing liquid downward perpendicularly.
[0024] The dish washer 100 further comprises a upper part rack 120 which is installed on the high side of the upper part nozzle 150 to make the dishes washed by the upper part nozzle 150 , a lower part rack 130 which is installed on the high side of the lower part nozzle 160 to make the dishes washed by the lower part nozzle 160 .
[0025] Particularly, the upper rack 120 is supported by the rail 108 which is placed on the inner side of the tub 110 , and accomplishes the back and forth movement.
[0026] The door 111 is united with the tub 110 on the end part of the low side of the door 111 by a hinge(not shown), and is able to rotate toward the up and down directions with the hinge as centering by a user's operation. A detergent case 114 that a certain amount of the detergent is input little by little is formed on the inside of the door 111 , and a rinse case 116 which make the rinse supplied during the rinsing is formed on a side of the detergent case 114 .
[0027] A sterilizing apparatus 200 which sterilizes the bacteria remained on the dishes after finishing the washing stroke is formed on an inner side of the door 111 .
[0028] A exhaust fan 118 is formed on a prescribed state of the door 111 , so the inner part air of the tub 110 is exhausted compulsorily to the outside by the exhaust fan 118 .
[0029] Hereinafter, the operations of the dish washer 100 according to the present invention will be explained.
[0030] First, a user opens the door 111 of the dish washer 100 , pulls the upper part rack 120 and the lower part rack 130 toward outside of the washing chamber. And, puts the dishes on the racks 120 , 130 . Next, closes the door 111 and approves the power, then the dish washer 100 is operated.
[0031] When the washing stroke is progressed as the power of the dish washer 100 is approved, the washing liquid is flew into the sump 170 , and the washing motor 190 is operated after finishing the washing liquid flowing step. And, as an impeller(not shown) which is placed on the inner part of the washing pump 170 connected with the washing motor 190 is rotated, the washing liquid is pumped into the lower part nozzle 160 and the water guide 140 .
[0032] Also, the liquid which is pumped into the water guide 140 is finally flew into the top nozzle 155 and the upper part nozzle 150 , and spouted out toward the inner part of a washing chamber. And, passed through the process that the dishes accommodated on the racks 120 , 130 are washed by the jetted washing liquid.
[0033] In the above-mentioned, as the top nozzle 155 spouts the washing liquid downward perpendicularly and the upper part nozzle 150 spouts the washing liquid upward perpendicularly, the dishes accommodated on the upper rack 120 are washed.
[0034] As the lower part nozzle 160 spouts the washing liquid upward perpendicularly, the dishes accommodated on the lower rack 130 are washed. And, composed that the upper parts of the dishes accommodated on the lower rack 130 are washed at the same time, as a spouting outlet is formed on the lower part of the upper part nozzle 150 , and the washing liquid is spouted toward the both sides of up and down.
[0035] After the washing process is finished, the foreign elements are leached out from the foul washing liquid stored on the sump 170 through a filter(not shown). The washing liquid that the foreign elements are leached out is discharged out of the dish washer 100 through a draining pump(not shown).
[0036] After the washing liquid is discharged out of the dish washer 100 , the clean washing liquid is flew into the sump 170 from the outside, and spouted out through the spouting nozzles 150 , 160 as the same with the afore-mentioned washing process. And, the dishes are passed through the rinsing process by the spouted clean liquid.
[0037] After the rinsing process is finished, as passed through the drying process, the washing process is completed. At this time, after finishing the drying process and the washing process, the sterilizing apparatus is operated for sterilizing the bacteria which isn't sterilized as passed through the rinsing process during the custody of the dishes.
[0038] Hereinafter, the structure of the sterilizing apparatus 200 will be explained in detail.
[0039] FIG. 3 is a magnified view of the part A of FIG. 2 .
[0040] Referring to FIG. 3 , it is distinctive that the sterilizing apparatus 200 according to the present invention is installed on the door 111 as the afore-mentioned.
[0041] Particularly, the sterilizing apparatus 200 comprises a ultraviolet rays generating section 210 which emits the ultraviolet rays into the inner part of the tub 110 , so the sterilizing of the dishes, etc. is progressed, a cover member 220 which prevents the inflow of the washing liquid into the ultraviolet rays generating section 210 during the washing stroke.
[0042] In the above-mentioned, for the ultraviolet rays generating section 210 , an ultraviolet rays lamp which occurs the ultraviolet rays or at least one of the LED(Light-Emitting Diode) can be used.
[0043] The ultraviolet rays generating section 210 applied the power as connected with a power supply section 260 by the electric wires placed on the inner side of the door 111 .
[0044] The cover member 220 can be possessed as capable of taking out and sticking on the door 111 by an adhesion member 270 to make the ultraviolet rays generating section 210 replaced easily.
[0045] Desirably, the cover member 220 is formed as a texture that the ultraviolet rays occurred on the ultraviolet rays generating section 210 can be transmitted easily. The cover member 220 can be formed as a quartz glass texture to improve the permeability of the emitted light.
[0046] A scattering prevention section 260 can be formed as united on the inner side of the cover member 220 to prevent the scattering of the broken pieces in case that the cover member 220 is broken as being shocked. Stainless steel, iron, fiber can be used for the scattering prevention section 260 , and desirably, the scattering prevention section 260 is formed as a mashed form.
[0047] A reflection member 230 is provided on the rear of the ultraviolet rays generating section 210 to improve the luminescence efficiency of the ultraviolet rays generating section 210 .
[0048] That is, the reflection member 230 improves the sterilizing capacity as reflecting the ultraviolet rays which is occurred on the ultraviolet rays generating section 210 into the inner side of the tub 110 . At this part, the reflection member 230 is formed as bended toward the door 111 to increase the reflecting efficiency, and according to this, a depressed part 112 as a form opposed with the reflection member 230 is formed on the inner side of the door 111 .
[0049] A fixation section 240 is placed to fix the ultraviolet rays generating section 210 on the sterilizing apparatus 200 . The fixation section 240 can be formed as covering the both sides of the ultraviolet rays lamp in case that the ultraviolet rays lamp is used as the ultraviolet rays generating section 210 .
[0050] Therefore, the damage and injury are prevented when the door is opened or closed, as the shaking of the ultraviolet rays generating section 210 is prevented as being fixed by the fixation section 240 .
[0051] At this part, the fixation section 240 can be formed separately with the reflection member 230 or the fixation section 240 and the refection member 230 can be formed a single body.
[0052] A sealer 224 which prevents the flowing of the washing liquid into the ultraviolet rays generating section 210 is placed on the contacting part of the cover 220 and the door 111 .
[0053] As giving the explanations about the operations of the sterilizing apparatus according to the above-mentioned constitution: the dish washing is started as the power is supplied to the dish washer 100 , and passed through the rinsing process after the washing operation is finished. At this time, the sterilizing operation for the dishes is progressed by the hot temperature washing liquid on the rinsing process. And, the dry process is passed through if the rinsing process is finished, then the washing stroke is completed.
[0054] At this time, the sterilizing apparatus 200 is operated to sterilize the bacteria which isn't sterilized during the rinsing process for the second time after the dry process or the washing stroke is completed.
[0055] Particularly, after the power is approved to the ultraviolet rays generating section 210 from the power supply section 260 , the ultraviolet rays generating section 210 emits the ultraviolet rays into the inner part of the tub 110 . At this time, a prescribed amount of the ultraviolet rays which is emitted on the ultraviolet ray generating section 210 improves the sterilizing efficiency as reflected into the inner part of the tub 110 by the reflection section 230 .
[0056] On the other hand, in order to replace the ultraviolet rays generating section 210 according to a user's necessity or the obstacles, separate the cover member 220 from the door 111 for the first. And, as install the cover member 220 again after that on the door 111 after replacing the ultraviolet rays generating section 210 , the replacement of the ultraviolet rays generating section 210 is completed.
[0057] As above-explained, it is advantageous that the ultraviolet rays generating section 210 is replaced easily as the sterilizing apparatus 200 is installed on the door 111 and the cover member 220 is formed as capable of attaching and separating on the door 111 . | A dish washer according to the present invention comprises: a tub for holding dishes and opened an one end thereof; a door for selectively sealing the opened end of the tub, and have a depressed part with a little of depth on an inner side; and a sterilizing apparatus which is installed on the door; wherein the sterilizing apparatus includes an ultraviolet rays generating section which occurs the ultraviolet rays, a reflection member which is installed on the depressed part, and reflects the ultraviolet rays which is occurred on an ultraviolet rays generating section into the inner side of the tub, and a cover member which prevents the influx of the washing liquid into an ultraviolet rays generating section. | 0 |
This is a divisional of U.S. patent application Ser. No. 08/481,755, filed on Jun. 7, 1995, which has issued as U.S. Pat. No. 5,650,071.
The present invention relates to a new and improved dialysis system and technique for automatically priming and recirculating fluid through a dialyzer and a disposable blood tubing set which connects a patient to a dialysis machine.
BACKGROUND OF THE INVENTION
A dialysis system is used as a substitute for the natural kidney functions of a human body. The dialysis system cleans the blood of the natural accumulation of bodily wastes by separating the wastes from the blood outside or extracorporeally of the body. The separated wastes are discharged and the cleansed blood is returned to the body.
The dialysis system consists of a dialysis machine, a dialyzer, a disposable blood tubing set and a supply of chemicals for producing a dialysate solution used within the dialyzer. The dialyzer is used with the dialysis machine to separate the wastes from the blood. The dialyzer includes a porous membrane located within a closed housing which effectively separates the housing into a blood compartment and a dialysate or filtrate compartment. The blood removed from the patient flows through the disposable blood tubing set and the blood side of the dialyzer. The dialysate solution prepared from the chemicals is passed through the dialysate side of the dialyzer. The wastes from the blood pass through the membrane by osmosis, ionic transfer or fluid transport into the dialysate and, depending upon the type of dialysis treatment, desirable components from the dialysate may pass in the opposite direction through the membrane and into the blood. The transfer of the wastes into the dialysate cleanses the blood while allowing the desired components from the dialysate to enter the bloodstream.
The transfer of blood between the patient and the dialyzer occurs within a disposable blood tubing set. The blood tubing set and the dialyzer represent a closed extracorporeal path through which the patient's blood travels. The blood tubing set includes an arterial line connected to an arterial reservoir for drawing blood from a patient, a venous line connected to a venous reservoir for returning blood to the patient, and a number of other lines for connecting a pump and the dialyzer between the arterial and venous reservoirs. Before the blood tubing set and the dialyzer can be used in a dialysis treatment, both must be primed with a sterile saline solution to remove air from the extracorporeal circuit. Once primed, the saline solution is recirculated through the blood tubing set and the dialyzer to produce a stabilized flow and remove additional trapped air from within the extracorporeal circuit. The priming and recirculating process also serves to clean the dialyzer and flush the dialyzer membrane of any debris or chemicals remaining from a prior use.
If a patient reuses the same dialyzer for subsequent dialysis treatments, that dialyzer must be cleaned with a disinfectant or sterilant solution. However, the sterilant itself must be cleaned from the dialyzer prior to each dialysis treatment. Such a cleaning procedure effectively takes place when the dialyzer undergoes the priming and recirculating process discussed above. During priming, the dialyzer is flushed with saline solution which removes a majority of the sterilant. Additionally, during recirculation of the saline solution, the dialysis machine can be commanded to remove or "pull" a predetermined flow of saline directly from the dialyzer. This predetermined flow corresponds to "pulling off" a predetermined amount of fluid (or weight) from a patient during dialysis, and is commonly referred to as "ultrafiltration." Removing saline by ultrafiltration during recirculation of the saline solution thus allows the remaining sterilant within the dialyzer to be removed as it mixes with the saline. The saline that is removed by ultrafiltration is replenished from a saline source connected to the extracorporeal circuit so that no additional air is added to the extracorporeal circuit during recirculation.
Current dialysis machines require that the priming and recirculation steps be undertaken separately, and further require an operator to alter the configuration of the blood tubing set and the saline source upon the conclusion of the priming step and before the start of the recirculation step. For example, a typical priming sequence on a conventional dialysis machine requires that the operator connect the outlet of the dialysis machine (i.e., the venous line) to a saline source and then operate the dialysis machine in reverse to fill the extracorporeal circuit with saline. Initially, the priming solution passes through the dialyzer and, in light of the reverse flow, exits the extracorporeal circuit through the dialysis machine's input line (i.e., the arterial line) which the operator connects to a waste basin or drain to dispose of the priming solution. The initial priming solution is discarded because it may contain relatively large quantities of sterilant flushed from the dialyzer when the dialyzer is sterilized and reused following a previous dialysis treatment.
Once the blood tubing set and dialyzer have been primed, the operator must disconnect the venous and arterial lines of the blood tubing set from the saline source and waste basin, respectively, and then connect the venous and arterial lines together (i.e., short circuiting the patient). The operator then switches the dialysis machine from its reverse operation and operates the machine normally to recirculate the saline solution through the extracorporeal circuit. The operator must further connect the saline source to a different portion of the circuit so that additional saline may be supplied to replace the saline removed by ultrafiltration during recirculation.
Thus, the processes of priming and recirculating conventional dialysis machines requires significant attention from a trained operator. The operator must configure the machine at several points during the process. Of the two separate procedures, recirculating the saline requires more time than initially priming the circuit with saline. Thus, if the operator is distracted after beginning the priming procedure and is unable to immediately return to the machine to reconfigure the blood tubing set and begin the recirculation procedure, a significant delay may be experienced in preparing the machine for the next patient. The potential for delay is significantly increased in a hospital or clinical setting where an operator or nurse must set up a number of different dialysis machines over the course of a day and where there is a greater possibility of distraction.
Additionally, while a skilled nurse or technician would be unlikely to make a mistake during the set up of a dialysis machine, the often hectic atmosphere of a hospital or clinic increases the chances of an error in machine set-up. For example, an operator may become distracted while the dialysis machine is recirculating and pulling saline from the dialyzer. If the saline source (e.g., a typical saline bag) were to run dry while the operator was distracted, the machine would continue to pull saline through the dialyzer and would tend to empty the extracorporeal circuit of saline, thereby allowing air to enter the circuit. Once a significant amount of air is introduced into the circuit, the priming and recirculation process must be started over at the cost of machine down-time and a new bag of sterile saline solution. Furthermore, although hospitals and dialysis clinics typically establish specific parameters for the set up and use of dialysis machines, these specific parameters may not be adhered to by an operator when setting up a particular dialysis machine. For example, inconsistent priming or recirculation procedures (such as too little saline during priming or running the machine for too short a time during recirculation) may be followed when the operator is distracted during the course of setting up the dialysis machine or when a hospital or clinic hires a new operator that is unfamiliar with the established set-up parameters.
These and other considerations have contributed to the evolution of the present invention which is summarized below.
SUMMARY OF THE INVENTION
One of the significant aspects of the present invention pertains to a new method of priming and recirculating sterile fluid through an extracorporeal circuit of a dialysis machine without requiring that a dialysis machine operator modify the configuration of the dialysis machine between the separate steps of priming and recirculating. Another significant aspect of the present invention relates to freeing a dialysis machine operator to attend other duties while the dialysis machine automatically primes and recirculates sterile fluid through the extracorporeal circuit prior to connecting the dialysis machine to a patient. A further significant aspect of the present invention relates to providing a method of priming and recirculating a dialysis machine which consistently follows specific priming and recirculation parameters established by a hospital or clinic, and which is not subject to human error after the priming and recirculating process has been initiated. A further significant aspect of the present invention relates to conserving the sterile solution used to prime the extracorporeal circuit and which is recirculated through the circuit after the circuit has been initially primed.
In accordance with these and other aspects, the present invention may be generally summarized as a method of setting up a dialysis machine having a blood pump, a dialyzer, and a blood tubing set which includes an arterial line for drawing blood from a patient, an arterial reservoir for storing the blood received from the patient, a venous reservoir for storing the blood pumped from the arterial reservoir through the dialyzer, and a venous line for returning the blood from the venous reservoir to the patient. The dialysis machine incorporating the present invention further includes a connector adapted to connect the arterial line and the venous line to a waste line leading to a waste drain, and a waste valve positioned along the waste line between the connector and the waste drain. The connector is preferably one element of the disposable blood tubing set.
The waste valve may be selectively opened and closed to drain fluid from either the arterial line or the venous line (when the waste valve is opened) and to transfer fluid between the arterial and venous lines through the connector (when the waste valve is closed). By selectively operating the blood pump and the waste valve, in addition to clamps attached to both the arterial and the venous lines, the dialysis machine can automatically complete both the priming and the recirculation procedure without the assistance of the dialysis machine operator. The operator is required to connect a source of sterile fluid (e.g., a saline bag) to the blood tubing set, and connect the arterial and venous lines to the waste line via the connector, before commanding the dialysis machine to begin the priming and recirculating process.
The process of priming and recirculating fluid through the extracorporeal circuit preferably includes the following steps: closing an arterial clamp on the arterial line to prevent fluid from filling the arterial line; filling the arterial reservoir with a sterile solution; opening the arterial clamp and the waste valve to fill the arterial line with sterile solution from the arterial reservoir and to allow some amount of the sterile solution within the arterial line to drain through the connector and down the waste drain past the open waste valve; closing the arterial clamp to preserve the sterile solution within the arterial line; opening a venous clamp on the venous line and running the pump in a forward direction to draw sterile solution from the arterial reservoir through the dialyzer and the venous reservoir and to allow the sterile solution to drain through the venous line and the connector and down the waste drain past the open waste valve; closing the waste valve, opening the arterial clamp and running the pump backwards to circulate the sterile solution backwards through the dialyzer and the blood tubing set to remove air from the dialyzer; and running the pump forward to recirculate the sterile solution through the dialyzer and the blood tubing set.
Additional steps may be added to the basic sequence of steps noted above. For example, fluid may be drawn directly from the dialyzer while the sterile solution is being recirculated through the dialyzer and the blood tubing set.
The above steps are preferably controlled automatically by the dialysis machine, although one or more of the initial steps may be performed manually by the dialysis machine operator while still remaining within the scope of the present invention. The substantially automatic control of the priming and recirculating process both frees the dialysis machine operator to attend to other responsibilities and reduces the potential for errors by the operator. Additionally, the automatic nature of the set-up process provides a consistently prepared dialysis machine and typically utilizes less sterile saline solution than manual priming and recirculation procedures.
A more complete appreciation of the present invention and its scope may be obtained from the accompanying drawings, which are briefly summarized below, from the following detailed descriptions of presently preferred embodiments of the invention, and from the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a dialysis machine which incorporates the present invention.
FIG. 2 is a generalized view illustrating a dialyzer, an extracorporeal blood flow path from a patient through the dialyzer, and a dialysate flow path through the dialyzer, as are present during treatment of a patient with the dialysis machine shown in FIG. 1.
FIGS. 3-7 generally illustrate a dialyzer connected to a blood tubing set which together define the extracorporeal flow path shown in FIG. 2, each of FIGS. 3-7 showing a different stage within a priming and recirculating process which prepares the dialysis machine shown in FIG. 1 for use with a patient.
FIG. 8 is a generalized section view of a connector of the present invention connecting an arterial line and a venous line to a waste port on the dialysis machine shown in FIG. 1.
DETAILED DESCRIPTION
An example of a dialysis machine with which the present invention may be advantageously employed is shown at 30 in FIG. 1. The dialysis machine 30 includes an enclosure 32 to which are attached, or within which are housed, those functional devices and components of the dialysis machine 30 which are generally illustrated in FIG. 2. The enclosure 30 also includes a conventional input/output ("I/O") device for controlling the machine 30, such as a touch-screen monitor 33 as shown in FIG. 1.
The dialysis machine 30 includes at least one blood pump 34 which controls the flow of blood from a patient 36. An arterial line or tubing 38 is connected through an arterial clamp 40 to a blood handling cartridge 42. The blood handling cartridge 42 is normally retained behind a door 44 (FIG. 1) of the machine 30 when used, thus the blood handling cartridge 42 is not shown in FIG. 1. The blood pump 34 also is located behind the door 44 adjacent to the cartridge 42. The blood pump 34 in dialysis machines is typically a peristaltic pump.
Blood from the patient 36 flows through an extracorporeal circuit when the arterial clamp 40 is open and the blood pump 34 draws blood from the patient 36. The blood passes through the arterial line 38 and into an arterial reservoir 46 of the cartridge 42. The blood pump 34 draws blood from the arterial reservoir 46 through a pump header 48 which is squeezed or pinched by a rotating rotor 49 against a stationary raceway 50, in the typical manner of peristaltic pumps. The blood within the pump header 48 which is rotationally in front of the rotor 49 is propelled through the pump header 48 and into a manifold 51 of the cartridge 42. A tubing 52 conducts the blood from the manifold 51 of the cartridge 42 into a blood inlet 53 of a conventional dialyzer 54. A micro-porous membrane or other type of dialysis medium 56 divides the interior of the dialyzer 54 into a blood chamber 58 and a dialysate chamber 60.
As the patient's blood passes through the dialyzer 54, the waste products within the blood pass through the medium 56 where they mix with the dialysate in the chamber 60. The cleansed blood then exits the dialyzer 54 through a blood outlet 61 and is then transferred through a tubing 62 to an inlet 63 of a venous reservoir 64 of the cartridge 42. Any air which might have been unintentionally introduced into the blood is collected and removed while the blood is in the venous reservoir 64.
Blood exits the venous reservoir 64 through an outlet 65 and is removed from the cartridge 42 through a venous tubing or line 66. Although not shown in FIG. 2, a venous blood pump similar to the arterial blood pump 34 may be located along the venous line 66 to assist in returning the blood to the patient 36. If employed, the venous blood pump is positioned behind a second door 68 as shown in FIG. 1.
After leaving the venous reservoir 64, the blood flows through the venous line 66 to an air detector 70. The air detector 70 derives signals related to the quantity of air, if any, remaining in the venous line 66. If an excessive or dangerous amount of air is present, a venous line clamp 72 will immediately close and the blood pump 34 will stop to terminate the flow of blood through the venous line 66 before the detected air reaches the patient 36.
The enclosure 32 of the dialysis machine 30 also encloses the various elements of a dialysate flow path, shown in abbreviated form in FIG. 2. The elements of the dialysate flow path include a number of different valves (most of which are not shown) and a dialysate pump 74 which draws dialysate from a container or from an internal supply 76 of dialysate which the dialysis machine 30 has prepared from appropriate chemicals and a supply of purified water.
The dialysate pump 74 draws the dialysate from the supply 76 and delivers the dialysate through a dialysate supply tubing or line 78 to an inlet 79 of the dialysate chamber 60 of the dialyzer 54. The dialysate flows past the medium 56 where it absorbs the waste products from the blood in the blood chamber 58. Any beneficial components within the dialysate which are desired to be transferred to the blood pass through the medium 56 and enter the blood in the blood chamber 58.
Dialysate containing the waste products exits the dialysate chamber 60 through an outlet 81 and is removed from the dialyzer 54 through a dialysate waste tubing or line 82 by operation of a drain pump 84. The drain pump 84 may be operated at a lesser volumetric pumping rate compared to the volumetric pumping rate of the dialysate pump 74 when it is desired to transfer components from the dialysate into the blood by fluid transport within the dialyzer 54. The drain pump 84 is operated at a greater volumetric pumping rate compared to the volumetric pumping rate of the dialysate pump 74 when it is desired to remove fluid components from the blood by fluid transport. Both of these flow control techniques are known as ultrafiltration and are well known dialysis treatments.
The dialysate removed from the dialyzer 54 is delivered through the waste tubing 82 to a waste drain 86. The waste drain 86 may be a separate container which receives the used dialysate and accumulated waste products, or it may simply be a drain to a public sewer. The various valves and pumps which control the dialysate flow path are referred to generally as the dialysate hydraulics.
Because the blood in the extracorporeal flow path is prone to clot, it is typical to inject an anticoagulant such as heparin into the extracorporeal flow path. The typical approach to injecting the anticoagulant is to slowly deliver it from a syringe 89. A plunger 90 of the syringe is slowly and controllably displaced into the syringe 89 by a linear driver mechanism (not shown), which is typically referred to as the anticoagulant pump. Anticoagulant from the syringe 89 is introduced into the manifold 51 of the cartridge 42 through a tubing 92 connected to the syringe as shown in FIG. 2. The anticoagulant pump is controlled to deliver the desired amount of anticoagulant during the dialysis treatment by the degree to which the anticoagulant pump moves the plunger 90 into the syringe 89 over a given time period.
Tubings 94 and 96 are respectively connected to the arterial reservoir 46 and venous reservoir 64 of the cartridge 42 as shown in FIG. 2. Clamps or caps (not shown) are connected to the ends of the tubings 94 and 96 to selectively vent accumulated air from the reservoirs 46 and 64. A saline tubing 98 is also connected to the arterial reservoir 46 so that saline may be directly administered to the patient during treatment in case of low blood pressure. A pole 100 for supporting a conventional saline bag is attached to a side of the enclosure 32, as shown in FIG. 1. Additionally, medicines or other additives may be introduced into the blood through the access tubing 94 during treatment.
The reservoirs 46 and 64 and the manifold 51 of the blood handling cartridge 42, together with the tubes 38, 48, 52, 62 and 66, are collectively referred to as a blood tubing set ("BTS"). The BTS is disposable and is typically discarded after each dialysis treatment. Similarly, the dialyzer 54 is termed a disposable product, although it is not uncommon for a dialyzer to be reused with a single patient. A dialyzer will typically be reused by a patient who regularly visits the same clinic for dialysis treatments. Following each treatment, the dialyzer is cleaned with a sterilant and is then stored until the patient's next visit to the clinic. The dialyzer must then be thoroughly cleaned before use to ensure that the sterilant is not transferred to the patient's bloodstream during the next dialysis treatment.
Before each treatment, the disposable BTS and the dialyzer 54 (regardless of whether the dialyzer is new or "used") must be attached to a dialysis machine 30 and prepared for a patient's use by an operator. While the disposable BTS is sterile and thus does not need to be cleaned, the BTS and the dialyzer 54 must be primed with a sterile saline solution to remove the air from the extracorporeal circuit. In addition to flushing the dialyzer 54 with saline solution during priming, the saline solution must be recirculated through the dialyzer for a predetermined period of time to ensure that substantially all of the sterilant or other chemical debris within the dialyzer has been removed. This recirculation process also establishes a stable flow within the extracorporeal circuit and ensures that any remaining air within the circuit has been removed before the patient is connected to the machine 30. Once the priming and recirculating process is completed and the circuit is filled with saline, the arterial line 38 is attached to the patient and the patient's blood is drawn through the circuit. The venous line 66 is connected to the waste drain 86 to dispose of the used saline solution and, at the point the patient's blood has displaced all the saline within the circuit, the venous line is connected to the patient, as shown in FIG. 2.
The automatic nature of the present invention allows a dialysis machine operator to attach the BTS and the dialyzer 54 to the dialysis machine 30 and make a small number of other connections to the BTS prior to commanding the machine 30 to perform both the priming and the recirculation procedures discussed above. Upon the conclusion of the recirculation procedure, the machine 30 will place itself in a steady state mode and provide an indication that it is ready for connection to a patient.
The present invention utilizes the known elements of the dialysis machine and the BTS mentioned above, together with two new components to achieve its automatic functionality. First, as shown in FIG. 3, the BTS includes a Y- or T-shaped connector 102 (FIG. 8) which is adapted to commonly connect the ends of the arterial line 38 and the venous line 66 to a waste line 104 which, in turn, is connected to the waste basin or drain 86. The waste line 104 is considered to be separate from the waste tubing 82 (FIG. 2) leading from the outlet 81 of the dialyzer 54, although one skilled in the art could utilize a single waste tubing for both purposes. Secondly, a waste valve 106 is used to selectively open and close the waste line 104. When the valve 106 is open, fluid within the Y-shaped connector 102 is directed to the waste drain 86. However, the valve 106 may be closed to effectively connect the arterial line 38 to the venous line 66 through the Y connector 102 when the arterial and venous clamps 40 and 72 are open.
In an alternative preferred embodiment (FIG. 8), the waste valve 106 may be internal to the dialysis machine 30 so that an external waste handling port 107 may be used to connect the connector 102 to the waste drain 86. Details of such a waste handling port for use on a dialysis machine may be found in U.S. Pat. No. 5,041,215, entitled Dialysis Unit Priming and assigned to the assignee hereof, the disclosure of which is incorporated herein by this reference. When the waste handling port 107 is utilized, as shown in FIG. 8, a male portion 112 of the Y-shaped connector 102 is inserted directly within the port 107. The waste line 104 is connected to a bottom end of the port 107 and passes through the waste valve 106 (not shown in FIG. 8) which is internal to the dialysis machine enclosure 32. The port 107 preferably defines a relatively large gap 114 between the male portion 112 of the connector 102 and the waste line 104 to provide a sterile "air barrier" between the Y-shaped connector 102 and fluid within the waste line 104. The remaining two ends 116 and 118 of the Y-shaped connector 102 preferably include male Luer connectors for connection to the arterial and venous lines 38 and 66, respectively.
Although the Y-shaped connector 102 is preferably pre-attached to the arterial and venous lines 38 and 66 as shown in FIG. 8 (and may be pre-attached to the waste line 104 when the external waste valve 106 is used as shown in FIGS. 3-7), the Y-shaped connector may be packaged separately for attachment to blood tubing sets which do not include a Y-shaped connector. Additionally, while the waste port 107 and the internal waste valve 106 are preferably used as shown in FIG. 8, the waste valve 106 is illustrated with the waste drain 86 on the exterior of the dialysis machine in FIGS. 3-7 for the sake of clarity in describing the remainder of the invention.
Before the start of the priming process, the operator must attach the BTS (including the Y-shaped connector 102 and the attached waste line 104) and the dialyzer 54 to the dialysis machine 30 as shown in FIG. 1. The pump header 48 (FIG. 2) is placed about the pump rotor 49 and the tubings 52 and 62 are connected to the dialyzer 54, as shown in FIG. 3. Next, the operator must pass the lines 38 and 66 through their respective clamps 40 and 72, and connect the waste line 104 through the waste valve 106 to the waste drain 86.
After connecting the various lines as shown in FIG. 3 and ensuring that the clamps 40 and 72 are closed, the operator must hang a bag 108 of sterilized saline from the pole 100 (FIG. 1) and, after spiking the bag, connect a line 110 from the bag 108 to the saline tubing 98 on the arterial reservoir 46. The operator then opens the cap on the tubing 94 leading from the arterial reservoir 46, thus allowing saline from the bag 108 to gravity fill the arterial reservoir 46 as air within the reservoir 46 escapes through the tubing 94. Once the arterial reservoir 46 is mostly filled with saline (FIG. 3), the operator closes the cap on the tubing 94. The dialysis machine 30 is now set for priming and recirculation, and the operator's sole remaining task is to select the automatic prime and recirculate function from the touch screen 33 (FIG. 1).
Once commanded to begin, the dialysis machine initiates the priming procedure, as shown in FIG. 4, by opening the arterial clamp 40 and the waste valve 106, thereby allowing the saline within the arterial reservoir 46 to flush the air out of the arterial line 38 before it is disposed of down the waste drain 86. The saline within the arterial reservoir 46 is replenished from saline within the bag 108, and the machine 30 closes the arterial clamp 40 after a predetermined time period to preserve the sterile saline solution within the bag 108. However, the predetermined time is sufficient to clear the air from the arterial line 38.
The machine 30 immediately initiates the next step in the automatic priming process, as shown in FIG. 5, by closing the arterial clamp 40 and opening the venous clamp 72. The machine then commands the pump rotor 49 to turn in a forward direction to fill the remainder of the extracorporeal circuit (the BTS and the dialyzer 54) with saline from the bag 108. The saline passes through the pump header 48, the manifold 51, the tubing 52, the dialyzer 54 and the tubing 62 before entering the venous reservoir 64. The saline then drains from the outlet 65 (FIG. 2) of the venous reservoir and through the venous line 66 (past the open venous clamp 72) and the Y-shaped connector 102 to the waste drain 86. During this step, additional saline is drawn from the bag 108 to maintain saline level within the arterial reservoir 46.
Priming the circuit in this manner serves to either flush a new dialyzer 54 (as is typically recommended by dialyzer manufacturers) or to cleanse a majority of the sterilant from a reused dialyzer. Additionally, a majority of the air within the BTS and the dialyzer 54 is expelled with the saline (and any sterilant flushed from the dialyzer) down the waste drain 86. However, some air will remain trapped within the dialyzer 54, and this trapped air typically floats to the top of the blood chamber 58 adjacent the inlet 53.
The next step in the automatic priming sequence, shown in FIG. 6, is to close the waste valve 106, open the arterial clamp 40, and run the blood pump rotor 49 backwards to push the saline solution backwards through the extracorporeal circuit. The fluid is pushed out of the arterial reservoir 46, through the Y-shaped connector 102, into the venous reservoir 64 and backward through the dialyzer 54 so that a portion of the air within the venous reservoir 64, together with the air trapped at the top of the dialyzer 54, is pushed out the inlet 53 and into the manifold 51. The entrained air bubbles are then forced by the pump 34 into the arterial reservoir 46 where they collect at the top of the reservoir. As more air bubbles are forced into the arterial reservoir 46, the increased air volume at the top of the reservoir reduces the level of saline in the arterial reservoir 46 while simultaneously preventing additional saline from entering the reservoir 46 through the saline tubing 98, as shown in FIG. 6A.
Once the air has been forced out of the BTS and the dialyzer 54, and the fluid levels in the reservoirs 64 and 46 have been adjusted, the machine 30 automatically switches from the priming procedure to the recirculation procedure without the need to reconfigure any of the connections of the dialyzer, the saline bag or the BTS. The recirculation procedure, as shown in FIG. 7, entails closing the waste valve 106, opening the arterial and venous clamps 40 and 72, and running the blood pump 34 forward while the machine 30 commands the hydraulics responsible for the dialysate flow path to pull a predetermined level of fluid from the dialyzer 54 across the medium 56.
In essence, the recirculation process mimics the normal dialysis process while short circuiting the patient 36 by connecting the arterial and venous lines 38 and 66, respectively, through the Y-shaped connector 102. By commanding the dialysate hydraulics to pull a certain amount of fluid from the blood chamber 58 of the dialyzer 54, the machine 30 is essentially conducting ultrafiltration. However, the liquid pulled through the medium 56 comprises only the saline solution and any sterilant still remaining within the dialyzer 54 following the priming procedure. The recirculation process thus helps to ensure that a reused dialyzer is properly cleansed before it is connected to a patient.
To prevent air from filling the extracorporeal circuit as saline is pulled from the dialyzer during recirculation, additional saline is gravity fed from the bag 108 into the arterial reservoir 46. The recirculation process also helps to collect any air remaining within either the dialyzer 54 or the BTS and deposit the air at the tops of both the venous and the arterial reservoirs 64 and 46. The air collected within these reservoirs can then be vented at the conclusion of the recirculation process by opening the clamps (not shown) on the tubes 96 and 94, respectively.
After a predetermined time during which the touch screen monitor 33 (FIG. 1) may provide a count-down timer to display the time remaining for recirculation, the machine 30 notifies the operator via an audible signal (in conjunction with an indication on the touch screen monitor 33) that the recirculation process has been completed. Simultaneously, the machine commands the dialysate hydraulics to stop pulling fluid through the dialyzer medium 56 and simply allows the pump to continue recirculating the saline through the extracorporeal circuit. By halting the "ultrafiltration" process, the machine 30 conserves the saline that must be drawn from the bag 108 to replenish the fluid pulled from the dialyzer.
Although no additional fluid is pulled from the extracorporeal circuit, the machine continues to recirculate the saline within the circuit until the patient is ready to be connected to the machine. In addition to maintaining an established flow, the continued recirculation helps to dilute any potential pockets of sterilant remaining within the dialyzer.
The operator thus knows when the machine 30 has finished both the priming and the recirculation procedures. The operator further knows that if the patient is delayed, the machine will continue its beneficial recirculation function while not wasting any saline once the machine has halted the ultrafiltration process. The clinic can thus set its parameters, including the predetermined times and fluid volumes used for each step of the priming and recirculating process, so that a sufficient level of saline remains within the bag 108 for use during the dialysis treatment. As noted above, the saline bag 108 is left attached to the saline tube 98 of the arterial reservoir 46 during patient treatment. Although the saline line 110 will normally be clamped during the dialysis treatment, the line 110 may be opened in case the patient experiences low blood pressure and requires an influx of fluid.
Once the priming and recirculation procedures are completed, the operator needs only to clamp the lines 94 and 110 and disconnect the arterial line 38 from the Y-shaped connector 102. A leashed cap 120 on the Y-shaped connector is placed over the end 116 to prevent saline within the BTS from spilling out of the Y-shaped connector 102 once the arterial line 38 is disconnected. The arterial line 38 is then attached to the patient 36, as shown in FIG. 2. As the patient's blood displaces the saline solution within the extracorporeal circuit, the venous line 66 remains connected to the waste drain 86 through the Y-shaped connector 102 to dispose of the recirculated saline. Once the patient's blood reaches the end of the venous line 66, the venous line is disconnected from the end 118 of the Y-shaped connector 102 and attached to the patient as shown in FIG. 2. The disposable Y-shaped connector 102 may then be discarded. The dialysis treatment thus progresses in a normal fashion from this point.
As noted above, the different steps of the automatic priming and recirculating process, as shown in FIGS. 4-7, require that the various clamps be opened and closed at specific predetermined times and that the pump rotor 49 be run in various directions and at various speeds for predetermined durations. A microprocessor (not shown) within the enclosure 32 is programmed to operate the clamps and pumps as described above to perform both the priming and the recirculation procedures. Thus, the different hospitals and clinics using the dialysis machine 30 need only program the microprocessor with the different predetermined times and durations (and their corresponding fluid volumes) according to a specific set of parameters previously established by the hospital or clinic. As an example only, and not by way of limitation, during the step in the automatic priming process shown in FIG. 4, the machine 30 may be programmed to open the arterial clamp 40 for 7 seconds to flush the arterial line 38 with the saline stored in the arterial reservoir 46. The clinic may have previously determined through testing that the 7 second period is sufficient to completely flush the air out of the arterial line 38, and that leaving the clamp 40 open for a longer period would only serve to waste the sterile saline solution. Similarly, the clinic will typically establish a parameter for the amount of time the blood pump 34 is to run in the recirculation step shown in FIG. 7 before the dialysate hydraulics are commanded to stop pulling fluid through the dialyzer medium (e.g., 20 minutes). Alternatively, the lengths of the different steps may be varied with different types of dialyzers. These predetermined times (and the corresponding predetermined volume of saline used) will have been established by the clinic to both ensure that a sufficient amount of time and saline solution is allowed to achieve the desired effect, and to prevent both time and saline solution from being wasted by extending the step for an excessive period of time.
Additionally, variations on a particular step may be programmed into the machine 30 to account for changing variables. For instance, as mentioned above, the step of priming the venous side of the circuit, including the dialyzer 54 (FIG. 5), can be altered when a new dialyzer is used. Dialyzer manufacturers typically require that a new dialyzer be flushed with saline for a longer period than a dialyzer which is being reused. Thus, when the machine 30 is informed that a new dialyzer is being used, it can prolong the step shown in FIG. 5 to meet the manufacturer's requirements. Similarly, if a plate dialyzer is utilized in place of the more typical hollow fiber dialyzers illustrated in FIGS. 1-7, the dialyzer manufacturer typically suggests that the dialyzer be subjected to a high pressure flow during priming to expand the plates within the dialyzer (similar to blowing up a balloon). If the machine 30 is informed that a plate dialyzer is being used, it may alter the above-described step of resetting the fluid level in the venous reservoir 64 by closing the venous clamp 72 for a longer period of time and allowing the pressure within the dialyzer to rise to a greater level before popping open the venous clamp 72.
Thus, the significant contribution of the present invention is that a clinic or hospital may be certain that their established parameters for setting up a dialysis machine are being precisely followed with no possibility of human error or distraction. Also, the machine 30 may be programmed for different contingencies, such as using different types of dialyzers. However, the greatest benefit of the present invention is that it allows busy nurses or dialysis operators the freedom to direct their attention elsewhere while the dialysis machine automatically cycles through the various steps of the priming and the recirculation procedures. The operator no longer has to revisit a dialysis machine and change the configuration of the blood tubing set over the course of the machine set-up. Rather, the operator is only required to make a limited number of connections before starting the procedure and then, after informing the machine of all the potential variable parameters (i.e., the type of dialyzer used), command the machine to start the procedure. The operator can then turn his or her attention to other patients or other machines requiring set up, comfortable in the knowledge that the dialysis machine will complete the priming and recirculation procedures according to the preestablished parameters and then notify the operator when it is ready to be connected to a patient. In clinical settings where large numbers of machines must be set up, the present invention can save a great deal of operator time, while simultaneously ensuring that each machine is being set up in a manner consistent with the clinic's established parameters. The labor savings associated with the present invention, together with the savings realized from using an optimum amount of saline during the priming and recirculation procedures, translates to a notable monetary savings to hospitals and dialysis clinics.
The technique of the present invention relates both to the novel method of priming and recirculating a dialysis machine and the unique apparatus which enables the machine to carry out the new method. This apparatus includes the waste valve 106 (not previously used on dialysis machines) and the Y-shaped connector 102 (not previously included with conventional blood tubing sets). Additionally, while a preferred embodiment of the present invention is illustrated with a double-needle dialysis treatment (i.e., using a single pump 34 to draw and return blood to the patient at two separate locations as shown in FIG. 2), one skilled in the art could apply the same technique to a dialysis machine which utilizes two separate blood pumps to both draw and return blood from a single location on the patient (i.e., "single-needle, double-pump" machines). As noted above, provision is made for the inclusion of a second blood pump (not shown) on the face of the enclosure 32 behind the door 68 (FIG. 1). Furthermore, while the presently preferred embodiment of the invention requires the dialysis operator to initially fill the arterial reservoir by unclamping and then clamping the air tubing 94 (FIG. 3), one skilled in the art would be able to automate this step in the priming and recirculating process similar to the remaining steps shown in FIGS. 4-7.
The present invention could be utilized with existing dialysis machines once they have been fitted with the waste valve 106 (and appropriate microprocessor software for controlling the blood pump and the valves), in addition to the arterial clamp 40 if the machine does not already include an arterial clamp (as is common with some single pump dialysis machines). Additionally, conventional blood tubing sets must be modified to include the Y-shaped connector 102. Thus, the present invention may be utilized with both new and existing dialysis machines which include the above-described apparatus.
A presently preferred embodiment of the present invention and many of its improvements have been described with a degree of particularity. This description is a preferred example of implementing the invention, and is not necessarily intended to limit the scope of the invention. The scope of the invention is defined by the following claims. | A technique for automatically priming and recirculating sterile fluid through an extracorporeal circuit of a dialysis machine having a blood pump, a dialyzer, and a blood tubing set including an arterial line for drawing blood from a patient and a venous line for returning the blood to the patient. The dialysis machine selectively opens and closes clamps on the arterial and venous lines and further operates a waste valve for selectively opening and closing a waste line leading to a waste drain. A connector attaches both the arterial and venous lines to the waste line downstream of the arterial and venous clamps and upstream of the waste valve. The dialysis machine automatically operating the blood pump, the clamps and the waste valve to flush the dialyzer and the blood tubing set with the sterile fluid and direct the used fluid down the waste drain. The dialysis machine then operating the blood pump and the clamps to again fill the dialyzer and the blood tubing set with additional sterile fluid and recirculate the sterile fluid through the extracorporeal circuit without the assistance of a dialysis machine operator. The dialysis machine further providing the operator with an indication when the recirculation process is complete. The connector being either one component of the disposable blood tubing set or a permanent component fixed to the dialysis machine. | 0 |
FIELD OF THE INVENTION
This invention relates to a method of establishing dedicated logical connections, also termed "frame relay channels", between a newly added port or physical interface in a data communications network and those already so connected in the network.
BACKGROUND OF THE INVENTION
Companies, such as banks, insurance companies, etc., generate masses of information which in the course of business they must frequently transmit, in the form of electronic digital data, from one office location to another, often at great distance (e.g., New York to London). The cost of transmitting such data becomes very high unless the data is efficiently multiplexed and then transmitted in a cost effective way over a high speed communication link (e.g., a leased "T-1" telephone line operating at 1.544 megabits per second).
Ascom Timeplex, Inc., manufactures and sells to a world-wide market digital data transmission equipment under the tradename "Synchrony". This equipment takes advantage of the latest in digital data technology. Synchrony data transport equipment (hereinafter referred to as "ST") multiplexes or packages a customer's digital data at one location and transmits the data at high speed in a cost-effective way to any location the customer desires to communicate with by taking best advantage of existing communications links, such as "T-1" lines, satellite links, etc.
A customer, who is already using a Synchrony network for data transmission, often has its own telephone PBXs (private branch exchanges) at various office locations. It is highly desirable from the standpoint of cost savings that telephone calls also be routed from PBX to PBX via the Synchrony network rather than over a commercial telephone network (e.g., AT&T).
The capability of routing telephone calls through a Synchrony network is provided by a unit within an "ST" node termed a "D-channel Server Module" (DSM) associated with a port, termed a PBX port to which a respective PBX is connected. Each PBX is served exclusively by one PBX port. The PBX communicates with the PBX port in order to place calls through the ST network to another PBX, and in order to receive such calls.
The PBX is physically attached to an "ST" node's Input/Output port ("I/O port") by means of a cable. The "I/O port" is programmed to provide communications between the PBX and the PBX port. The I/O port may or may not be in the same ST node as the PBX port.
When a new PBX port and PBX are added to the network of PBX ports and PBXs it is necessary, in order that the newly added PBX be able to communicate directly with already interconnected PBXs, to establish a permanently dedicated logical connection termed a "frame relay channel" (FRC) between the new PBX port and each of the existing PBX ports. In other words, there must be a permanent FRC from the new PBX port to every other PBX port supporting the various PBXs. This arrangement of frame relay channels (FRCs) is termed a "full mesh". Where there are only two PBX ports only one FRC is required; for four PBX ports, six FRCs are needed; where there are ten PBX ports, there are needed forty-five FRCs, and twenty PBX ports need 190 FRCs, and so on in an ever expanding progression.
In the absence of the invention, when a new PBX port (supporting a new PBX) is added to an existing Synchrony network, the necessary FRCs have to be established manually one at a time. This is not much of a burden when only a few PBX ports are involved. But the task of establishing FRCs becomes time consuming and tedious with larger numbers of PBX ports (e.g., ten, or twenty, or more). Moreover, considerable care is required not to miss establishing a required FRC, or to needlessly duplicate already existing FRCs.
It is desirable to have a method which greatly facilitates in time and effort the establishing of all of the needed FRCs between all of the existing PBX ports and a newly added PBX port without omission and without duplication.
SUMMARY OF THE INVENTION
In accordance with the invention there is provided a method of adding a new private branch exchange interface (PBX port) to a data communication network having a number of existing interfaces (PBX ports).
The network comprises a plurality of nodes each of which comprises a data transport for sending and receiving customer data at high speed to each of the other nodes. The nodes are interconnected with each other by high speed data links (e.g., T-1 lines). The network is administered by a network management system computer having a database. Each node may have contained in it one or more of the existing PBX ports (each connected to its associated PBX). The method of adding a new PBX port comprises the steps of: manually determining with the aid of the computer database a suitable address for the new PBX port; manually determining with the aid of the computer database a correct address of an arbitrarily selected one of the existing PBX ports; instructing the computer to search the database for all other addresses of existing PBX ports to which the existing selected PBX port is connected and to compile a list of such other addresses; and instructing the computer to establish a set of direct dedicated channels ("frame relay channels") for communication between the address of the new PBX port and each one of the addresses of the existing PBX ports, such that PBXs connected to the respective existing ports are able to communicate directly with the new PBX via the data network and its nodes.
In accordance with another aspect of the invention there is provided a method of adding a private branch exchange (PBX) and associated new interface PBX port to a data communications network having a plurality of PBXs already connected at respective existing interface PBX ports of the network and able to communicate directly from PBX to PBX via the network. The method comprises steps of determining from a computer database of the network a suitable address within the network of PBX ports for the new PBX port being added; determining from the database a correct address of any one of the existing PBX ports already connected to the network; compiling from the database all additional addresses of existing PBX ports connected to the existing one PBX port; forming new address-pairs of the new PBX port and each one of the existing PBX ports; and establishing for each new address-pair a direct dedicated communication channel such that the new and existing PBXs connected at respective PBX ports of the network can communicate via the network directly with each other.
Viewed from another aspect, the present invention is directed to a method of adding a new private branch exchange interface (PBX port) to a data communication network having a number of existing PBX ports. The network comprises a plurality of nodes each of which includes a data transport for sending and receiving customer data at high speed to each of the other nodes. The nodes are interconnected with each other by high speed data links. The network is administered by a network management system computer having a database. The existing PBX ports are connected to respective ones of the nodes. The method comprises the steps of: manually determining with the aid of the computer database a suitable address for the new PBX port; manually determining with the aid of the computer database a correct address of a selected, arbitrary one of the existing PBX ports; instructing the computer to search the database for all other addresses of existing PBX ports to which the selected one PBX port is connected and to compile a list of such other addresses; and instructing the computer to establish a respective direct dedicated channel for communication between the address of the new PBX port and each one of the addresses of the existing PBX ports such that PBXs connected to the respective PBX ports are able to communicate directly with any of the new and existing PBXs via the data network and its nodes.
Viewed from still another aspect, the present invention is directed to a method of adding a new private branch exchange interface (PBX port) to a data communications network having a number of existing PBX ports. The network has a plurality of nodes each of which comprises a data transport for sending and receiving customer data at high speed to each of the other nodes. The nodes are interconnected with each other by high speed data links. The network is administered by a network management system computer having a database. Each of the PBX ports is connected to a respective one of the nodes. Each of the PBX ports has a respective multi-part address including an address of a node in which it is contained. The method comprises the steps of: manually determining with the aid of the system computer a suitable multi-part address for the new PBX port and storing the new address in memory; manually determining with the aid of the system computer a correct multi-part address for a selected, arbitrary one of the existing PBX ports and storing the selected one PBX port address in memory; instructing the system computer to search the database and to compile existing addresses of all other PBX ports which are coupled via the network to the existing selected PBX port; and instructing the system computer to establish a set of dedicated frame relay channels for communication between the address of the new PBX port and the addresses of each one of existing PBX ports, such that a PBX connected to any PBX port can communicate via the network of nodes to any PBX connected to any of the other PBX ports.
A better understanding of the invention will best be gained from the following description given in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic block diagram showing a data transmission network of interconnected "ST" (Synchrony transport) nodes and a network management computer system (ST-NMS) useful in the method of the invention;
FIG. 2 is a schematic block diagram of a portion of the network of FIG. 1 showing existing DSM (D-channel server module) PBX ports associated with an "ST" unit (not shown) and showing separate PBXs connected to the respective ports;
FIG. 3 is a schematic block diagram of the PBX ports of FIG. 2 indicating how a new or additional PBX port and its associated DSM and PBX are interconnected into the network of FIG. 1;
FIG. 4 is a schematic illustration of an image produced on a monitor screen of the ST-NMS of FIG. 1 illustrating steps in the method provided by the present invention; and
FIG. 5 is a schematic illustration of another image produced on a monitor screen of the ST-NMS in accordance with the present invention.
DETAILED DESCRIPTION
Referring now to FIG. 1, there is shown a schematic block diagram of a data transmission network 10. The network 10 comprises a number of nodes 12 of Synchrony Transport equipment (ST) shown within a respective solid-line box 16, interconnecting data paths 18, and a network management system (ST-NMS) 20. There may be more or fewer nodes 12 in the network 10 than the five shown here. Each node 12 with its respective ST 16 is connected to one or more of the others via one of the respective data transmission paths 18 which can be a "T-1" telephone line, satellite link, etc. Each ST 16 may contain one or more PBX ports (not shown in FIG. 1 but shown in FIG. 2) to which can be connected user equipment such as a PBX. Each ST 16 multiplexes data fed into it from its ports and transmits the data at high speed at best efficiency to another ST 16 via a respective data path 18, or the data may be passed through a series of ST 16 units, and their respective data paths 18, before reaching the destination ST 16. A receiving ST 16 demultiplexes the data received and applies it to a selected port or ports. The network management system 20 comprises a computer 21 (having a keyboard), a monitor 22, and a mouse 23.
Referring now to FIG. 2, there is schematically illustrated a network (mesh) 24 representing a portion of the network 10 (nodes 12 not being shown here). In the network 24 are illustratively shown three D-channel server module (PBX) ports 26 designated "A", "B" and "C". Each PBX port 26 has connected to it a respective PBX 28, designated here PBX "A", PBX "B" and PBX "C". Each of the PBX ports 26 is connected to each of the others via respective ones of frame relay channels (FRCs) 30 to be described in greater detail hereinafter. It is to be understood that though a ST 16 at a node 12 is not shown here, the PBX ports 26 are distributed among one or more such ST 16 units, which in turn are interconnected via the high speed paths 18 (see FIG. 1).
Referring now to FIG. 3, there is shown a network (mesh) 34 otherwise identical to the network 24 (FIG. 2) but having an additional PBX port 36, designated "D", an additional PBX 38, designated PBX "D", and as indicated by dotted lines, additional frame relay channels (FRCs) 40 which must be established to connect the new PBX port 36 to each of the existing PBX ports 26. In essence, a new PBX port 36 and a new PBX 38 have been added to the combination shown in FIG. 2. It is to be understood that there may be a larger number of existing PBX ports 26 (e.g., ten, or twenty, or more) than the three shown here by way of example. How the FRC channels 40 (and 30) are established in accordance with a method the present invention will now be described.
Referring now to FIG. 4, there is shown a schematic illustration of an image 50 as same would appear on the monitor 22 of the network management system computer 21 of FIG. 1. Information provided by the computer 21 in the image 50 (as stored in a database memory of the computer 21) is sequentially shown under a heading "new mesh member" in respective boxes 51-54 of FIG. 4, and under a heading "existing mesh member" in respective boxes 55-58 of FIG. 4. This information, as will be explained, represents the "addresses" or locations of Synchrony nodes (e.g., nodes 12 of FIG. 1) and respective DSMS and their ports (e.g., PBX ports 26 and 36 of FIG. 3).
As seen in the box 51 of the image 50, there are listed by way of example "ST" nodes numbered "5", "6", "20", "30", and "400". Initially the boxes 52 through 58 are empty and blank. None of the "ST" nodes within the box 51 is as yet highlighted. The image 50 FIG. 4 also shows PBX CREATE FRAME RELAY CHANNEL, RESET, CANCEL, and HELP within respective separate rectangular boxes.
A human operator of the computer 21 knows from a systems plan or map of the Synchrony network 10 (FIG. 1) and the network 34 (FIG. 3) that the ST node associated with the new PBX port 36 (designated "D") is number 400. Accordingly, the operator instructs the computer 21 via the mouse 23 to select or "highlight" the node 400 (as shown by the shaded area 60 in the box 51). After doing this the computer 21 then shows in the next box 52 that ST node 400 has only a single "shelf" numbered "1" available.
This shelf 1 represents a first (and only) shelf location in this example within an equipment rack of the ST node 400. The operator accordingly selects shelf 1 which the computer then highlights as a shaded area 62 in the box 52. Next, as is shown in the box 53, the computer monitor image 50 shows two DSM modules numbered "8" and "11" to be available. In this example the operator selects DSM "11" which is accordingly highlighted by a shaded area 63. Finally, as is shown in the box 54, the computer 21 shows that there is only one port numbered "65" available. Accordingly, the operator selects this port 65 as indicated by a shaded area 64.
Still referring to FIG. 4, the image 50 shows under the heading "existing mesh number" in a box 55 the same ST node numbers as shown in the box 51. ST node numbered 400 has now been designated as part of the "address" of the newly added PBX port 36 as was explained previously. Accordingly, it is now necessary for the operator to determine an address for an existing PBX port 26, either "A", "B" or "C" (FIG. 3). The operator determines from the network system map that, by way of example, an "ST" node numbered "5" appears to be associated with the existing PBX port 26, designated PBX port "A" (see FIG. 3). The operator therefore selects ST node numbered 5 in the box 55. The computer 21 thereupon highlights this node, as indicated by a shaded area 65, and then shows in the next box 56 a shelf "1". Since this is the only choice available, the operator selects shelf 1 which is then highlighted, as indicated by a shaded area 66. Then, in the next box 57, the computer 21 lists two available DSMS, numbers "12" and "15". By way of example, the operator selects DSM number 12 which is thereupon highlighted, as indicated by a shaded area 67.
Had the selection of DSM 12 been an impermissible choice, the number "12" DSM would not have been offered in the box 57. However, the choice of DSM 12 is correct and in the next box 58 there is shown availability of a port numbered "65". Since this is the only choice, the operator selects it as indicated by the shaded area 68. An "OK" button 69 (shown at the bottom left of the screen 50) becomes operative, and the user now selects it by means of the mouse 23.
It will be understood from the above description that considerable skill and knowledge is required on the part of the operator in selecting an address for the new PBX port 36 (port "D") and in determining a correct address for an existing PBX port 26 (e.g., port "A"). This process also partly involves trial and error by the operator in assembling permissible segments of the addresses. Accordingly, a fair amount of time and care is involved just in determining one address-pair.
After having correctly determined the addresses of the address-pair: "new PBX port "D"-existing PBX port A", the selection of the "OK" button 69 by the operator then instructs the computer 21 to search the database for all address-pairs in which the address of the existing PBX port 26 just identified (in this example, PBX port "A" of FIG. 3) appears. In this search (following the example given) the computer will identify the two address-pairs of: PBX port "A"-PBX port "B"; and PBX port "A"-PBX port "C" of FIG. 3 (but not the address-pair: PBX port "B"-PBX port "C"). Once the search is completed (in a second or so) the full set of existing PBX ports is identified. Now that new PBX port "D" and existing PBX ports "A", "B", and "C" are identified, the computer 21 concludes that three new FRCs are required.
Because a PBX port is involved in several FRCs (a separate FRC to each of the other PBX ports), there is an additional level of addressing, called a Data Link Connection Identifier (DLCI), which uniquely identifies an FRC within a PBX port, much as an apartment number uniquely identifies a residence within an apartment house. Therefore, the computer will now search its database to find available DLCIs, analogous to empty apartments. It identifies, in this example, three available DLCIs for PBX Port "D", one for PBX Port "A", one for PBX Port "B", and one for PBX Port "C". Thus, three new address-pairs are formed; D-A, D-B, and D-C, with no omissions. In our example, the D-A address pair happens to use DLCI #3 on PBX Port "D", and DLCI #3 on PBX Port "A".
Next, it is desirable to eliminate any duplicate FRC, in case PBX Port "D" was not completely new. Therefore, the computer 21 searches its database again, this time looking for any existing FRC which would be the same as any of the new address-pairs, considering only the PBX ports involved, and ignoring the specific DLCIs. Finding any such FRCs causes the computer 21 to drop the corresponding new address-pair. In our example, PBX Port "D" is completely new, so all three address-pairs are retained.
Thus all of the address-pairs required for the new FRC channels 40 (FIG. 3) are accurately and easily obtained, without omission and without duplication. This greatly simplifies the adding of a new PBX port (i.e., PBX port D) to the network 34, especially where a sizable number (e.g., ten, or twenty, or more) of PBX ports are involved.
Next, the computer 21 forms tentative FRCs in its own memory, one for each valid address-pair from the preceding processing. The computer thereafter removes the image 50 from the monitor 22, and displays an image 70, as is described below.
Referring now to FIG. 5, there is shown a schematic illustration of a subsequent image 70 as it appears on the monitor 22 of the computer 21 of FIG. 1. The image 70 is provided by the computer 21 subsequent to the image 50 and after a first address-pair: new PBX port "D"-existing PBX port "A" has been established. The image 70 in an upper horizontal row indicated at 72 shows the respective addresses of the DLCIs on PBX port "A" and PBX port "D" as "End Point ID: 5.1.12.65.3" and "End Point ID: 400.1.11.65.3", as previously identified.
The image 70 in a lower horizontal row indicated at 74 states "THIS CHANNEL IS COUPLED TO 2 BACKGROUND CHANNELS". This of course refers to the other two address-pairs: new PBX port "D"-PBX port "B", and new PBX port "D"-PBX port "C". The image 70 provides the operator with two sets of configuration options titled "FRAME RELAY CONFIGURATION" one of which is indicated at 76, and the other at 78. The image 70 of FIG. 5 also shows CONFIGURE PBX FRAME RELAY CHANNEL, CREATE TEMPLATE, SELECT & APPLY TEMPLATE, RETRIEVE, CANCEL, AND HELP within separate rectangular boxes.
The operator selects from among the various options listed the characteristics of a frame relay channel (FRC) to be established between the address-pair shown in the row 72, namely: existing PBX port "A"--new PBX port "D". After selection is complete, the operator so signals the computer 21, by selecting either a "Program" button 79 or a "Program and Connect" button 80, whereupon a respective FRC, with selected characteristics, is established between the address-pairs listed in the row 72 of the image 70, as well as the two address-pairs indicated in the row 74.
In this way the respective FRCs 40 illustrated in FIG. 3 are permanently established in the ST network 10 and stored in the computer database for use whenever called. The newly added PBX 38, designated PBX "D" (see FIG. 3) is now able to communicate directly with each and every existing PBX 28 over the partial Synchrony network 34 and the complete Synchrony network 10 (FIG. 1) of which the network 34 is a part.
The above description is to be understood as given in illustration and not in limitation of the invention. Various changes or modifications in the method of the invention as set forth may occur to those skilled in the art, and these may be made without departing from the spirit and scope of the invention as defined by the accompanying claims. | There is provided a method of adding a new private branch exchange interface (PBX port) to a data communication network having a number of existing PBX ports, each coupled to respective ones of data transport nodes for sending and receiving via high speed data links (e.g., T-1 lines) customer data to each of the other nodes. A network management system computer having a database is coupled to the network. The method of adding a new PBX port includes the steps of: determining with the aid of the computer database a suitable address for the new PBX port; determining with the aid of the computer database a correct address of a selected one of the existing PBX ports; searching the database for all other addresses of existing PBX ports to which the selected one PBX port is connected and compiling a list of such other addresses; and establishing a direct dedicated channel ("frame relay channel") for communication between the address of the new PBX port and each one of the addresses of the existing PBX ports such that PBXs connected to the respective PBX ports are able to communicate directly with any of the new and existing PBXs via the data network and its nodes. | 7 |
BACKGROUND OF THE INVENTION
This invention relates to sewing machines and, more particularly, to an arrangement for incorporation in an electronically controlled sewing machine to prevent improper sewing when a buttonhole pattern is selected and the buttonhole paddle switch and buttonhole presser foot are not properly located.
The application of electronics technology to sewing machines has resulted in a simplification in the machine-operator interface. For example, the sewing of a buttonhole pattern has been greatly simplified. The sewing of a buttonhole pattern is fully disclosed in U.S. Pat. No. 4,159,688, which issued on July 3, 1979, to Stephen A. Garron and Charles R. Odermann, the disclosure of which is hereby incorporated by reference. Simplification of the sewing of a buttonhole pattern is achieved by the electronic control of the sewing machine responding to signals generated by a buttonhole paddle switch cooperating with a buttonhole presser foot which includes a button size gauging arrangement. However, in order for the proper sewing of a buttonhole pattern, the paddle switch must be properly positioned by the operator at the start of sewing, the paddle switch being selectively movable between a retracted non-operative position and an extended operative position. If the paddle switch is not in its extended position and if the buttonhole presser foot is not moved to an initial starting position, the appropriate signals will not be generated by the paddle switch and the bottonhole will be improperly formed.
It is therefore an object of the present invention to provide an arrangement which alerts the operator that the paddle switch and presser foot are not properly positioned at the start of sewing of a buttonhole pattern.
Unfortunately, there may be times where the operator initiates the sewing of a buttonhole pattern and ignores the alarm signal for a number of stitches. The operator would then have to remove the work fabric from the sewing machine and carefully remove the stitches.
It is therefore another object of this invention to provide an arrangement which prevents stitches from being formed after selection of a buttonhole pattern unless the buttonhole paddle switch and the buttonhole presser foot are properly positioned.
SUMMARY OF THE INVENTION
The foregoing and additional objects are attained in accordance with the principles of this invention by providing an arrangement in an electronically controlled sewing machine for rendering inoperative at least one of the stitch forming instrumentalities of the sewing machine in response to the buttonhole paddle switch not being in its operative position when a buttonhole pattern is selected.
In accordance with an aspect of this invention, in addition to rendering inoperative the stitch forming instrumentality, an alarm is activated to alert the sewing machine operator of an improper operating condition.
In accordance with another aspect of this invention, when the stitch forming instrumentality is rendered inoperative, the electronic control is prevented from sequencing.
BRIEF DESCRIPTION OF THE DRAWINGS
The foregoing will be more readily apparent upon reading the following description in conjunction with the drawings wherein:
FIG. 1 is a perspective view of a portion of a sewing machine in which an arrangement constructed in accordance with the principles of this invention may be incorporated; and
FIG. 2 is a block schematic diagram of illustrative circuitry constructed in accordance with the principles of this invention.
DETAILED DESCRIPTION
Referring to the drawings, wherein like elements in different figures thereof have the same reference character applied thereto, FIG. 1 illustrates in phantom lines a sewing machine casing 10 including a bed 12 and a bracket arm 14 overhanging the bed 12. The illustrated sewing machine 10 is of the electronically controlled type wherein a pattern selected by the operator is automatically sewn. For an understanding of the manner in which automatic pattern sewing may be accomplished, the reader is referred to U.S. Pat. No. 3,872,808, issued to John W. Wurst on Mar. 25, 1975, the disclosure of which is hereby incorporated by reference.
The subject invention is concerned with the sewing of a buttonhole pattern. When a buttonhole pattern is to be sewn, a buttonhole presser foot 16 is installed on the presser bar 18. The buttonhole presser foot 16 is of the type described in U.S. Pat. No. 3,877,403, which issued to Stanley J. Ketterer on Apr. 15, 1975. The buttonhole presser foot 16 includes a button size gauging arrangement. Accordingly, the buttonhole presser foot 16 includes a fixed rear stop member 20 and an adjustable front stop member 22, the distance therebetween defining the length of the buttonhole pattern being sewn, as determined by the size of button inserted between an anchor element 24 and a buttonhole gauging element 26. The sewing machine further includes a switch mechanism including a lever arm 28 terminating in a paddle 30 at its lower end. The other end of the lever arm 28 is received by openings in a pair of spaced lugs 32 formed at one end of a lever 34. The lever arm 28 may therefore be selectively raised and lowered by an operator, between a retracted non-operative position and an extended operative position, the operator extending and lowering the lever arm 28 so that the paddle 30 is between the stops 20 and 22 during the formation of a buttonhole pattern.
The lever 34 is pivoted at 36 and at the end opposite the lugs 32 has a pin 38 mounted thereon for cooperation with an electrical switch member 40. The switch member 40 includes a first fixed contact 42 connected to a wire 44, a second fixed contact 46 connected to a wire 48, a first moveable contact 50 and a second moveable contact 52, the first and second moveable contacts 50 and 52 being connected to a wire 54. The pin 38 mounted on the lever 34 is between the moveable contacts 50 and 52. When the buttonhole presser foot 16 is positioned for needle penetrations at a first end of a buttonhole pattern, the paddle 30 is in contact with the stop 20 and is pushed forward so that the lever 34 pivots about the pivot point 36 and causes the pin 38 to push the moveable contact 50 against the fixed contact 42. At the other end of the buttonhole pattern, the buttonhole presser foot 16 is moved rearward so that the stop 22 moves the paddle 30 back which causes the lever 34 to pivot about the pivot point 36, causing the pin 38 to push the moveable contact 52 against the fixed contact 46.
At the start of sewing a buttonhole pattern, it is important that the paddle 30 extend downwardly as far as possible and that the presser foot 16 be positioned so that the stop 20 pushes the paddle 30 to move the moveable contact 50 against the fixed contact 42. Unless this initial action is taken, a defective buttonhole pattern will be sewn. The arrangement according to this invention prevents this from happening.
The sewing machine 10 also includes what is commonly referred to as a skip stitch mechanism. Such a mechanism is described in U.S. Pat. No. 3,847,100, which issued to Stephen Garron on Nov. 12, 1974, the disclosure of which is hereby incorporated by reference. As is well known in the art, the sewing machine 10 includes a needle 60 carried for endwise reciprocation by a needle bar 62 mounted for lateral jogging movement in a gate 64. The connections between the sewing machine arm shaft (not shown) and the needle bar 62 for imparting needle reciprocation include a separable connection indicated generally at 66 which is referred to in the art as a skip stitch mechanism. The skip stitch mechanism 66 is operatively connected to a needle bar release solenoid 68. When the solenoid 68 is energized momentarily, it will influence interruption of needle bar reciprocation to prevent the formation of stitches. The present invention utilizes this skip stitch mechanism to prevent a buttonhole pattern from being improperly sewn.
Referring now to FIG. 2, shown therein is a portion of the total circuitry which is responsive to operator selection of a pattern for controlling the operation of the sewing machine 10 to form stitches in a selected pattern in accordance with information stored in a memory, and also for preventing the sewing of a buttonhole pattern until the initial operating conditions of the buttonhole presser foot 16 and the paddle 30 are satisfied. The circuitry shown in FIG. 2 operates in accordance with the circuitry disclosed in the above-referenced Wurst U.S. Pat. No. 3,872,808, and includes a pattern selection circuit 101 which responds to operator selection of a desired pattern from a plurality of selectable patterns and includes operator actuable elements (not shown) disposed on the sewing machine 10. In response to operator actuation of one of those elements, the pattern selection circuit 101 provides an appropriate pattern selector code word on the leads 103 to the pattern address ROM 105. The pattern address ROM 105 provides over the leads 107 to the address counter 109 a code word representing the selected pattern. This code word on the leads 107 determines the starting point of the address counter 109 which has a count input line 111 upon which are provided pulses from an arm shaft pulse generator (not shown) over the line 113. The address counter 109 has output leads 115 which are connected to the inputs of a pattern ROM 117. The pattern ROM 117 has output lines 119 upon which are provided a digital code word for the bight actuator system 121. Additionally, the pattern ROM 117 has output lines 123 upon which are provided a digital code word for the feed actuator system 125. The bight actuator system 121 and the feed actuator system 125 are similar in construction and are adapted to convert a digital code word from the pattern ROM 117 into a mechanical position which locates the sewing machine needle in a conventional stitch forming instrumentality and provides a specific work feed for each needle penetration, as described in the above-referenced U.S. Pat. No. 3,872,808.
Whenever a new pattern is selected, or a pattern is reselected, a pattern select pulse is applied to the lead 131 from the pattern selection circuit 101. Also, the pattern address ROM 105 provides output signals for energizing pattern indicator lights, illustratively light emitting diodes, which are disposed on the sewing machine 10 in proximity to graphical indicia so that an operator is informed as to which pattern has been selected. Accordingly, when a buttonhole pattern is selected, a high signal is applied to the lead 133 to energize the light emitting diode 135. Thus, whenever a buttonhole pattern is selected or reselected, the AND gate 137 emits a pulse on its output line 139 to set the bistable element, or flip flop, 141. Normally, the flip flop 141 is in its reset state with a high output on the lead 143 and a low output on the lead 145. In this condition, neither the alarm 147 nor the needle bar release solenoid 68 are activated. The high signal on the lead 143 passes through the OR gate 149 to enable the AND gate 151 to pass timing pulses from the lead 113 to the count input line 111 of the address counter 109. These pulses are also applied to the reset input 153 of the flip flop 141 to keep the flip flop 141 in its reset state.
As was previously mentioned, when the buttonhole pattern is selected or reselected, a pulse is applied to the lead 139 which sets the flip flop 141, causing the lead 145 to go high. The high signal on the lead 145 is amplified by the driver 155 to energize the needle bar release solenoid 68 so as to unlatch the needle bar 62 and prevent the formation of stitches. Additionally, the high signal on the lead 145, after a suitable delay as determined by the delay element 157, activates the alarm 147 to alert the operator in the event that the paddle 30 and presser foot 16 are not properly positioned. With the flip flop 141 in its set state, there is a low signal on the lead 143, removing the high signal through the OR gate 149 to the AND gate 151. In this condition, the only way that the AND gate 151 can pass the armshaft timing pulses on the lead 113 is for the paddle 30 and the buttonhole presser foot 16 to be properly positioned. In that case, the movable contact 50 touches the fixed contact 42 so that a ground is applied to the lead 44, which ground is inverted by the inverter 159 to provide a high signal on the lead 161. The high signal on the lead 161 passes through the OR gate 149 to enable the AND gate 151 to pass armshaft timing pulses therethrough when the sewing machine is operated. The first armshaft timing pulse will reset the flip flop 141, which results in a permanent enabling signal on the lead 143. With the flip flop 141 being reset, the high signal will be removed from the lead 145, de-energizing the needle bar release solenoid 68. If this condition occurs before the time delay period of the delay element 157, the alarm 147 will not have been activated.
If the buttonhole pattern had been selected while the paddle 30 and buttonhole presser foot 16 had not been properly positioned, the flip flop 141 would have remained in its set state, maintaining the needle bar release solenoid energized and causing the alarm 147 to be activated. Therefore, even if the sewing machine were to be operated, the armshaft timing pulses on the lead 113 would not pass through the AND gate 151 and the address counter 109 would not be incremented. When the operator responds to the fact that stitches are not being formed and/or that an alarm had been activated, the operator then properly positions the paddle 30 and the buttonhole presser foot 16. When the machine is subsequently run, the next armshaft timing pulse on the lead 113 resets the flip flop 141, de-energizing the needle bar release solenoid 68, deactivating the alarm 147, and passing armshaft timing pulses to the count input line 113 of the address counter 109, resulting in the sewing of a buttonhole pattern.
Accordingly, there has been disclosed an improved arrangement for preventing the sewing of a buttonhole pattern if the sewing machine is not properly set up. It is understood that the above-described arrangement is merely illustrative of the application of the principles of this invention, and it is only intended that this invention be limited by the scope of the appended claims. | An electronically controlled multiple pattern sewing machine is provided with an arrangement which senses when the buttonhole paddle and buttonhole presser foot are not properly positioned at the time a buttonhole pattern is selected to be sewn. Under these circumstances, an alarm is activated and stitches are not formed even though the operator may attempt to sew. | 3 |
This application claims the benefit of European Application No. 16170274.1 filed on May 19, 2016, the disclosure of which is expressly incorporated herein by reference.
BACKGROUND
The invention is concerned with the issue of how to produce n-pentanal by hydroformylation from feedstock mixtures comprising a small proportion of n-butene and a large proportion of n-butane. Specifically, solutions for further optimizing established processes for hydroformylation of such low-butene mixtures in terms of material utilization are sought.
The substance groups discussed in this connection are essentially alkenes (olefins), alkanes (paraffins), aldehydes and alcohols. These terms are used here in accordance with the terminology customary in chemistry.
In organic chemistry, substance groups are generally classified and named by the number of carbon atoms therein. The substance class of interest is preceded by the prefix C n , where n is the number of respective carbon atoms present in the substance. When reference is made to C 4 alkenes for example, this is understood to mean the four isomeric olefins having four carbon atoms, namely isobutene, 1-butene, cis-2-butene and trans-2-butene.
The saturated alkanes have barely any reactivity and are therefore used predominantly as fuel or aerosol propellant.
Meanwhile, it is possible to use the more reactive alkenes to form hydrocarbons having a greater number of carbon atoms which open up a broad spectrum of application and hence achieve higher sale prices than the starting materials having a smaller number of carbon atoms. This is how industrial organic chemistry adds value.
An economically important substance class which is produced from lower alkenes for this reason is that of the aldehydes. The aldehyde having three carbon atoms is called propanal. Two C 4 -aldehydes exist, namely n-butanal and isobutanal.
The aldehydes having five carbon atoms include the isomeric substances n-pentanal (also known as valeraldehyde), isopentanal (isovaleraldehyde), (S)-2-methylbutyraldehyde, (R)-2-methylbutyraldehyde and tert-pentanal. Valeraldehyde, used as a vulcanization accelerator, is of economic importance. Valeraldehyde may also be converted by aldol condensation and subsequent hydrogenation into 2-propylheptanol, an alcohol which is in turn a starting material for further syntheses toward PVC plasticizers, detergents and lubricants. Details may be found in U.S. Pat. No. 8,581,008.
n-Pentanal is produced by hydroformylation of n-butene.
n-Butene is an umbrella term for the three linear C 4 -olefins 1-butene, cis-2-butene and trans-2-butene. A mixture comprising these three isomeric substances is normally at issue; the precise composition depends on the thermodynamic state.
Hydroformylation (the oxo process) is generally understood to mean the conversion of unsaturated compounds such as in particular olefins with synthesis gas (hydrogen and carbon monoxide) into aldehydes having a number of carbon atoms one higher than the number of carbon atoms in the starting compounds. C 5 aldehydes are accordingly produced by hydroformylating butene.
A comprehensive account of the current state of the art of hydroformylation may be found in:
Armin Börner, Robert Franke: Hydroformylation. Fundamentals, Processes and Applications in Organic Synthesis. Volumes 1 and 2. Wiley-VCH, Weinheim, Germany 2016.
An established process for producing n-pentanal is disclosed in U.S. Pat. No. 9,272,973. The inventors proceed from this closest prior art.
In the hydroformylation for producing valeraldehyde practiced there an input mixture containing 35% 2-butenes and only 1% 1-butene is used. The remainder is butane which is inert toward the hydroformylation. The mixture extremely low in 1-butene is hydroformylated in the presence of a homogeneous catalyst system comprising a particular symmetrical biphosphite ligand which is stabilized by addition of an amine. Isononyl benzoate is mentioned as a solvent. With this catalyst system, butene conversions of 60% to 75% are achieved.
To enhance material efficiency WO2015/086634A1 proposes removing the unconverted alkenes from the reaction mixture using a membrane and converting them in a second hydroformylation stage with the aid of SILP technology. The inert alkanes are likewise discharged from the process with the membrane and thus do not cause any further disruption in the hydroformylation. This measure allows for very good material utilization, i.e. conversion into aldehydes, of the butenes present in the feedstock mixture. However, the butanes present in the feedstock mixture remain unutilized.
One option for better chemical utilization of alkanes than incinerating them is to dehydrogenate them. Dehydrogenation allows alkanes to be converted into more reactive and thus chemically versatile alkenes. Naturally, this requires energy. Since alkanes are relatively cheap raw materials a cost-effective dehydrogenation, especially performed in energy-efficient fashion, achieves significant added value. There is therefore a considerable range of commercially available technologies for dehydrogenation of alkanes, more particularly the C 3 -alkane propane, on offer. A comprehensive market analysis may be found in:
Victor Wan, Marianna Asaro: Propane Dehydrogenation Process Technologies, October 2015. Obtainable from IHS CHEMICAL, Process Economics Program RP267A.
Since propane dehydrogenation is operated in the sphere of naphtha crackers these processes are all configured and optimized for a petrochemical-scale throughput. Thus the capacity of a propane dehydrogenation according to the UHDE STAR® process is approximately 500 000 t/a of propylene (see PEP-Report cited above, pages 2-11). These are scales which differ very markedly from those of industrially operated hydroformylation; thus the capacity of a large oxo plant is only 100 000 t/a (Börner/Franke, Introduction). It thus hardly makes economic sense to dehydrogenate propane with the aid of a costly large-scale plant and then to hydroformylate a small portion of the recovered propene unless the excess propene is used for instance for production of polypropylene.
It is apparently for this reason that literature reports of a combination of a dehydrogenation with a subsequent hydroformylation are conspicuous in their rarity:
In the field of C 3 -chemistry, U.S. Pat. No. 6,914,162B2 describes a combination of a propane dehydrogenation with subsequent hydroformylation of the obtained propene. The dehydrogenation is arranged before the hydroformylation in the upstream direction. In this connection “upstream” means further up the added-value chain. A similar process which also operates with n-butane as the feedstock is outlined in US2006/0122436A1.
WO2015/132068A1 likewise describes the dehydrogenation of C 3 to C 5 alkanes with downstream (i.e. in the direction of added value) hydroformylation. However, the latter is carried out in the presence of a heterogeneous catalyst system which is why this process differs markedly from the presently industrially operated, homogeneously catalyzed oxo processes in terms of apparatus.
Another reason why the dehydrogenation and the hydroformylation are not combined in practice is that the dehydrogenation affords not only the desired alkenes but also very many other hydrocarbons which are a great hindrance in the hydroformylation. One example thereof is 1,3-butadiene for instance which acts as an inhibitor in the hydroformylation. Such contaminants must first be removed from the alkenes at great inconvenience (i.e. cost) before said alkenes may be hydroformylated.
The intermediate removal of substances formed in the dehydrogenation and undesired in the hydroformylation is addressed in U.S. Pat. No. 8,889,935. However this process is used primarily to produce the linear C 4 -olefin 1-butene by dehydrogenation of n-butane. It is proposed in this connection that the 2-butene generated as a byproduct in the dehydrogenation of n-butane be converted into n-pentanal by hydroformylation. Contaminants formed in the dehydrogenation such as 1,3-butadiene are derivatized/selectively hydrogenated before hydroformylation.
U.S. Pat. No. 5,998,685 discloses a process where feedstock mixtures comprising n-butane and isobutane are dehydrogenated and the thus obtained alkenes are initially oligomerized and the obtained olefin oligomers are finally hydroformylated. Since the catalysts employed in the oligomerization are likewise very sensitive to byproducts generated in the butane dehydrogenation a costly and complex purification is interposed.
In terms of the prior art it can be said that due to the differences in throughput rates and the inevitably formed contaminants the alkane dehydrogenation with subsequent hydroformylation has acquired no practical significance.
However, the reverse combination, where the hydroformylation is arranged in front of the dehydrogenation in the upstream direction, is hardly found in the patent literature either:
Thus MY140652A discloses a process for producing oxo alcohols where the alkanes not converted in the hydroformylation are removed from the hydroformylation mixture and subjected to a dehydrogenation. The thus obtained alkenes are mixed with the fresh feedstock and also isomerized before hydroformylation. The feedstock originates from a Fischer-Tropsch process and essentially comprises alkanes and alkenes having 8 to 10 carbon atoms.
In this process the alkanes are removed by distillation from alkenes not converted in the hydroformylation at great cost and complexity before dehydrogenation. This is because the presence of alkenes in the dehydrogenation is undesirable since due to their up to four-fold higher reactivity compared to alkanes they form many oxidation products such as CO and CO 2 which ultimately leads to rapid coking of the catalysts: cf. R. Nielsen: Process Economics Program Report 35F On-Purpose Butadiene Production II. December 2014, page 39 available from ihs.com/chemical. For the same reason providers of commercial dehydrogenation processes advise against introducing alkenes into the dehydrogenation.
The practical problem of contaminants requiring complex and costly removal is thus also present when a dehydrogenation is arranged downstream of a hydroformylation. In addition, even a world-scale oxo plant would scarcely be capable of keeping a dehydrogenation plant on a customary scale operating at anything approaching full capacity.
In conclusion it may be noted that the combination of dehydrogenation and hydroformylation or of hydroformylation and dehydrogenation is not industrially operated since the industrial scales do not coincide and because the specifications of the products and reactants of the respective processes are incompatible and thus necessitate a costly intermediate removal.
SUMMARY
Against this background, the present invention has for its object the development of a process for producing n-pentanal from feedstock mixtures comprising a small proportion of n-butene and a large proportion of n-butane in such a way that the material utilization of the feedstock mixture is enhanced. The process shall be capable of economic operation on an industrial scale. In particular an existing oxo plant shall be honed to achieve better raw material utilization.
This object is achieved by a combination of a hydroformylation and a dehydrogenation, wherein said combination has the special feature that the dehydrogenation is arranged after the hydroformylation in the downstream direction and is thus markedly smaller than conventional dehydrogenations provided upstream. A skillful product removal effectively removes contaminants formed in the process.
BRIEF DESCRIPTION OF THE DRAWINGS
Reference will now be made to the accompanying drawings wherein like reference characters designate the same or similar parts throughout the several views, and wherein:
FIG. 1 is a process flow diagram of the basic concept;
FIG. 2 is a process flow diagram of FIG. 1 additionally showing removal of secondary product; and
FIG. 3 is a process flow diagram of FIG. 1 additionally showing hydrogenation before dehydrogenation.
DETAILED DESCRIPTION
Specifically, the invention provides a process for producing n-pentanal comprising the steps of:
a) providing a feedstock mixture having the following composition which sums to 100 wt %:
n-butane: 70 wt % to 90 wt %; n-butene: 10 wt % to 30 wt %; 1-butene: 0 wt % to 3 wt %; isobutene: 0 wt % to 3 wt %; isobutane: 0 wt % to 3 wt %; 1,3-butadiene: 0 wt % to 1 wt %; other substances: 0 wt % to 1 wt %;
b) mixing the feedstock mixture with a recyclate to obtain a feed; c) treating the feed with carbon monoxide and hydrogen in the presence of a first catalyst system to convert at least a portion of the n-butene present in the feed into aldehydes by hydroformylation to obtain a hydroformylation mixture; d) recovering a primary product fraction from the hydroformylation mixture, wherein the primary product fraction has the following composition which sums to 100 wt %:
n-pentanal: 90 wt % to 98.5 wt %; 2-methylbutanal: 0 wt % to 5 wt %; 3-methylbutanal: 0 wt % to 3 wt %; other substances: 0 wt % to 2 wt %;
e) recovering a subsidiary fraction from the hydroformylation mixture, wherein the subsidiary fraction has the following composition which sums to 100 wt %:
n-butane: 80 wt % to 92 wt %; n-butene: 8 wt % to 20 wt %; other substances: 0 wt % to 1 wt %;
f) subjecting the subsidiary fraction to a dehydrogenation in the presence of a second catalyst system to obtain a dehydrogenation mixture having the following composition which sums to 100 wt %:
n-butene: 50 wt % to 60 wt %; n-butane: 40 wt % to 50 wt %; methane: 0 wt % to 4 wt %; ethene: 0 wt % to 3 wt %; propene: 0 wt % to 2 wt %; 1,3-butadiene: 0 wt % to 3 wt %; other substances: 0 wt % to 1 wt %;
g) subjecting the dehydrogenation mixture to a selective hydrogenation in the presence of a third catalyst system to obtain a hydrogenation mixture having the following composition which sums to 100 wt %:
n-butene: 50 wt % to 60 wt %; n-butane: 40 wt % to 50 wt %; 1,3-butadiene: 0 ppm by weight to 500 ppm by weight; other substances: 0 wt % to 5 wt %;
h) direct use of the hydrogenation mixture as recyclate
or purification of the hydrogenation mixture to obtain the recyclate.
The invention is based on the realization that it is possible at unexpectedly low cost and complexity to recover the n-butane not convertible in the hydroformylation as a subsidiary fraction, to dehydrogenate it, and to recycle the thus obtained butenes back into the hydroformylation to convert them into the desired aldehydes there. The carbon atoms present in the feedstock mixture are thus utilized very efficiently. It is surprising that the byproducts generated in not insignificant amounts in the dehydrogenation (these generally make up about 8 wt % of the effluent from the dehydrogenation) can be removed with separating means which are in any case present and this is why the additional cost and complexity for contaminant removal is low. This is because the hydroformylation is sensitive only to a few byproducts formed in a downstream dehydrogenation and, in addition to the n-pentanol, can even form further products of value from some of them. This has the result that the process is economic notwithstanding that the dehydrogenation results in increased energy requirements. Since the dehydrogenation is comparatively small its energy requirements may be covered at least partly by excess energy from other processes. More about that later.
As mentioned previously dehydrogenation is energy intensive. The efficiency of this process is thus strongly dependent on the catalyst system employed. The second catalyst system employed for the dehydrogenation is preferably a solid comprising platinum, tin and aluminum oxide. Further catalytically active materials such as zinc and/or calcium for example may also be present. The Al 2 O 3 is in particular modified with Zn and/or Ca. Such catalysts are often described as Pt/Zn systems and are disclosed in U.S. Pat. No. 4,152,365, U.S. Pat. No. 4,926,005 and U.S. Pat. No. 5,151,401. The dehydrogenation may be effected in the presence thereof in the gas phase at a pressure of 0.8*10 5 Pa to 1.2*10 5 Pa and a temperature of 450° C. to 700° C. The dehydrogenation is thus heterogeneously catalyzed which makes a complex and costly removal of the second catalyst system from the dehydrogenation mixture unnecessary. The dehydrogenation is preferably carried out at a relatively low temperature between 450° C. and 530° C., which saves energy. The thus achieved product spectrum is appropriate for the purpose required here. Even in this comparatively cold dehydrogenation the pressures should be between 0.8*10 5 Pa to 1.2*10 5 Pa.
Since the catalyst is deactivated over time due to coke deposits it needs to be regenerated or replaced regularly. This is made easier by the fact that at least two reactors, each heated and each filled with the second catalyst system, are provided for the dehydrogenation and the reactors are chargeable with subsidiary fraction individually or simultaneously in parallel and/or serially as desired. In this way it is always possible to shut down one reactor and deinstall/regenerate the dehydrogenation catalyst present therein while the other reactor continues to run. The process may accordingly be run continuously. Regeneration is effected by washing with (preferably hot) air or water vapor to burn off the coke. Regeneration is preferably effected in situ, i.e. without deinstallation from the reactor.
A particularly preferred development of the invention provides that the dehydrogenation is operated in an electrically heated reactor. Electrical heating is to be understood as comprehending both ohmic resistance heating and an inductively heated reactor.
An electrically heated dehydrogenation is unusual because such reactors are typically heated with fuel gas. Electrical heating is possible because the dehydrogenation employed here is comparatively small. Electrical heating has the decisive advantage that it may be operated with excess electrical energy as may be generated from renewable energy sources. The dehydrogenation may thus be deliberately operated when a great deal of electricity is generated from wind or solar power due to the prevailing weather conditions but is not in demand in the grid. In this way the plant may provide deliberate negative control capacity.
The selective hydrogenation serves to render harmless contaminants formed in the dehydrogenation, for example polyunsaturated hydrocarbons such as 1,3-butadiene. The valuable alkenes must not be hydrogenated. The selective hydrogenation is effected in the liquid phase at a pressure of 18*10 5 Pa to 22*10 5 Pa and at a temperature of 40° C. to 80° C. The catalyst employed is a fixed bed catalyst which comprises 0.1 to 2% by mass of palladium and a support material (activated carbon or aluminum oxide). The selective hydrogenation is effected in the presence of 0.05 to 10 ppm by mass of carbon monoxide based on the mass of the dehydrogenation mixture. The carbon monoxide serves as a moderator and may originate from the dehydrogenation itself. In this way the alkenes are preserved in the selective hydrogenation.
In contrast to the dehydrogenation the selective hydrogenation is effected in the liquid phase. The dehydrogenation mixture must therefore be liquefied before selective hydrogenation. The liquefaction is effected by compression and cooling. The heat recovered during cooling may be used for preheating the subsidiary fraction before dehydrogenation. This saves energy. It is thermodynamically advantageous to implement the cooling as an intercooling arranged between the compression stages.
Alternatively to the Pt/Sn systems the dehydrogenation may also employ a solid comprising aluminum oxide and chromium oxide. Such so-called chromia/alumina catalysts are disclosed in U.S. Pat. No. 3,665,049 and U.S. Pat. No. 3,778,388. The dehydrogenation is then effected in the gas phase at a pressure of 0.8*10 5 Pa to 1.2*10 5 Pa and a temperature of 600° C. to 700° C. The remarks made about the Pt/Sn system apply correspondingly to the chromia/alumina catalysts.
A further catalyst system suitable for the dehydrogenation comprises aluminum oxide and magnesiochromite. One example is disclosed in Finocchio et al. Catalysis Today 28 (1996) 381-389. With this catalyst the dehydrogenation is effected in the gas phase at a pressure of 0.8*10 5 Pa to 1.2*10 5 Pa and a temperature of 600° C. to 700° C.
As well as the recited heterogeneous systems the dehydrogenation may also be catalyzed homogeneously. This has the advantage that the dehydrogenation can be effected in the liquid phase which enhances process intensity and renders the liquefaction before selective hydrogenation unnecessary. The second catalyst system is then an organometallic compound dissolved in the dehydrogenation reaction mixture.
The organometallic compound may comprise iridium as the central atom to which at least one pincer ligand is complexed. The dehydrogenation would then be effected at a temperature of 100° C. to 250° C. and at a pressure of 800*10 5 Pa to 1200*10 5 Pa. Such a process is described in WO2014192020A2.
The organometallic compound may alternatively be [Rh(PMe3)2(CO)Cl]2. This is a photocatalyst which allows dehydrogenation under the action of UV radiation. This is particularly sustainable since sunlight may be used as the energy source:
Chowdhury, A. D., Weding, N., Julis, J., Franke, R., Jackstell, R. and Beller, M. (2014), Towards a Practical Development of Light-Driven Acceptorless Alkane Dehydrogenation. Angew. Chem. Int. Ed., 53: 6477-6481. doi:10.1002/anie.201402287
According to the invention the dehydrogenation is in principle effected without addition of an oxidant such as oxygen. It is not, therefore, an oxidative dehydrogenation (ODH).
Nevertheless, it may be advantageous to add a small amount of oxygen into the dehydrogenation as this allows coke deposits to be removed from the catalyst during normal operation. The heat thus formed is to the benefit of the endothermic dehydrogenation.
In this connection a “small amount of oxygen” is to be understood as meaning an oxygen amount from 1.4 wt % to 14 wt % based on the mass of n-butane present in the subsidiary fraction. This oxygen addition is markedly lower than in a conventional ODH.
In a preferred embodiment of the invention the hydrogenation mixture is mixed with the feedstock mixture as a recyclate without purification. This saves on capital expenditure but presupposes that the selective hydrogenation neutralizes all byproducts of the dehydrogenation that are disruptive toward the hydroformylation.
Ideally, the hydroformylation mixture is exclusively separated into the primary product fraction and the subsidiary fraction. This is possible when, with the exception of the n-butene, no components having a lower boiling point than n-butene are generated in the dehydrogenation.
However, in practice the dehydrogenation will form C 1 - to C 3 -hydrocarbons, for instance methane, ethene and propene. This requires a fractionation of the hydroformylation mixture into a low boiler fraction, the subsidiary fraction and the primary product fraction. The C 1 - to C 3 -hydrocarbons will then be found in the low boiler fraction.
Such a setup lends itself to fractionating the hydroformylation mixture into the low boiler fraction, the subsidiary fraction, the primary product fraction and into a secondary product fraction, wherein the secondary product fraction has the following composition which sums to 100 wt %:
propanal: 50 wt % to 70 wt %; n-butanal: 30 wt % to 50 wt %; other substances: 0 wt % to 10 wt %.
This is because the ethene and propene formed in the dehydrogenation is converted into the corresponding C 3 -/C 4 -aldehydes in the hydroformylation. In addition to the n-pentanal these aldehydes represent further products of value which are recovered as secondary product fraction.
The inherently undesired byproducts of the dehydrogenation (ethene, propene) may thus be utilized profitably. The effectiveness of common hydroformylation of a plurality of substrates is demonstrated in WO2015/132068A1 with further references.
A bonus effect of the formation of C 3 -/C 4 -aldehydes is that these bind in an azeotrope and thus discharge from the process any water of reaction formed. A separate water removal is thus rendered unnecessary.
Since in the process according to the invention the dehydrogenation is arranged after the hydroformylation in the downstream direction (i.e. in the direction of the added-value chain) a markedly lower production capacity than a commercially available dehydrogenation is sufficient. For arrangement behind an oxo plant on a current industry-standard scale it is sufficient for the apparatus of the dehydrogenation to be configured for continuous processing of a mass flow of the subsidiary fraction of less than 4 kg/s. This size corresponds in continuous operation (8000 h per year) to a plant capacity of 120 kt/a, approximately a fifth of the size that is customary today. A commercially available dehydrogenation plant cannot thus be used since it would be oversized and uneconomic.
Should the butene unconverted in the hydroformylation bring about excessive coking of the second catalyst system employed in the dehydrogenation, the butane/butene mixture could be hydrogenated before dehydrogenation. In this case the subsidiary fraction would be recovered by distillation with subsequent hydrogenation.
A particular advantage of the process described here is that it can be erected not only on greenfield sites but that it is also possible to add an appropriately small dehydrogenation to an existing oxo plant for C 4 -hydroformylation to enhance the material efficiency of the plant at low capital cost.
The present invention thus also provides for the use of a plant for dehydrogenation of alkanes comprising at least a heated reactor filled with a second catalyst system for retrofitting an existing plant for producing n-pentanal from feedstock mixtures comprising n-butene and n-butane by hydroformylation where the plant for dehydrogenation is arranged downstream of the plant for hydroformylation, said plant for dehydrogenation is fed with a subsidiary fraction from the hydroformylation and the effluent from the dehydrogenation is recycled into the hydroformylation with or without purification.
The process according to the invention shall now be elucidated with reference to process flow diagrams. In simple terms:
FIG. 1 : shows a process flow diagram of the basic concept;
FIG. 2 : is as FIG. 1 , additionally showing removal of secondary product;
FIG. 3 : is as FIG. 1 , additionally showing hydrogenation before dehydrogenation.
The basic concept of the process according to the invention is depicted in FIG. 1 . A feedstock mixture 1 obtained from outside the process and comprising predominantly n-butane and a residual amount of n-butene is mixed with a recyclate 2 to afford a feed 3 . The recyclate originates from the process itself, more about that later.
Feed 3 is run into hydroformylation 4 and there reacted together with synthesis gas 5 (a mixture of carbon monoxide and hydrogen) in customary fashion. Withdrawn from the hydroformylation 4 is a hydroformylation mixture 6 which comprises the desired n-pentanal (formed from the reaction of n-butene with synthesis gas), further byproducts, unconverted n-butene and, especially, unconverted n-butane. The necessary separation of the homogeneous first catalyst system used in the hydroformylation 4 is not depicted here.
In a separation sequence comprising three distillation columns 7 , 8 , 9 the hydroformylation mixture is fractionated by distillation. To this end the hydroformylation mixture 6 is run into the first column 7 and separated into tops product 10 and bottoms product 11 . The bottoms product 11 from the first column 7 is used to feed the second column 8 . Obtained at the bottom of the second column is a primary product fraction 12 which comprises the purified n-pentanal.
The tops product 13 from the second column 8 is mixed with the tops product 10 from the first column 7 and run into the third column 9 . At the top thereof a low boiler fraction 14 is withdrawn and at the bottom a subsidiary fraction 15 .
The subsidiary fraction essentially comprises the non-hydroformylatable n-butane and a significant proportion of n-butene not converted in the hydroformylation 4 .
In order to make the carbon atoms present in the subsidiary fraction 15 usable for the process, the subsidiary fraction 15 is initially preheated in a first heat exchanger 16 and then catalytically dehydrogenated in a dehydrogenation 17 . The dehydrogenation 17 is effected in the gas phase in the presence of a heterogeneous second catalyst system, optionally with addition of small amounts of oxygen 18 .
The dehydrogenation requires thermal energy which is preferably electrically generated. It will be appreciated that traditional heating with fuel gas is also possible.
In the course of the dehydrogenation the n-butane present in the subsidiary fraction 15 is converted into n-butene. Further substances are formed, such as 1,3-butadiene, methane, ethene, propene for instance. The dehydrogenation mixture 19 comprising these substances is withdrawn from the dehydrogenation in gaseous form and then compressed in a first compressor stage 20 . The heat from the compressor thus generated is removed by a second heat exchanger 21 and the dehydrogenation mixture 19 is thus intercooled. The heat generated in the intercooling is utilized for preheating the subsidiary fraction 15 before entry into the dehydrogenation 17 . To this end the first heat exchanger 16 and the second heat exchanger 21 are interconnected via a circuit 22 which contains a heat transfer medium. The ultimate liquefaction of the dehydrogenation mixture 19 is effected in a second compressor stage 23 .
The now liquid dehydrogenation mixture is now subjected to a selective hydrogenation 24 in the presence of a heterogeneous third catalyst system with addition of hydrogen 25 and carbon monoxide 26 as moderator. The selective hydrogenation 24 hydrogenates and thus neutralizes undesired polyunsaturated compounds such as 1,3-butadiene. The alkenes, by contrast, are preserved.
The hydrogenation mixture 27 withdrawn from the selective hydrogenation 24 is mixed as recyclate 2 with the feedstock mixture 1 and thus ultimately made available to the process again.
The hydrogenation mixture 27 may optionally also be purified and then mixed as recyclate 2 with the feedstock mixture 1 . However, this is not preferred and therefore not depicted.
The inventive dehydrogenation and recycling of the recyclate 2 has the effect that the butanes present in the subsidiary fraction 15 reenter the hydroformylation in the form, thanks to the dehydrogenation, of butenes and can there be converted into the primary product n-pentanal. The material efficiency of the process is thus enhanced compared to hydroformylation without dehydrogenation.
As previously mentioned the dehydrogenation 17 produces not only n-butene but also ethene and propene—both hydroformylatable substrates. Provided that the rate of formation of ethene and propene is high enough a fourth column 28 may be provided in the separation sequence, as depicted in FIG. 2 . The fourth column 28 is fed with the tops product 13 from the second column 8 . A secondary product fraction 29 comprising propanal and n-butanal, both formed from ethene and propene in the hydroformylation 4 , may then be withdrawn from the bottom of the fourth column 28 . The tops product 30 from the fourth column 28 is mixed with the tops product 10 from the first column 7 and run into the third column 9 .
A further alternative embodiment is shown in FIG. 3 . Here, the subsidiary fraction 15 is obtained when the bottoms product from the third column 9 is hydrogenated with hydrogen 25 in a hydrogenation 31 . This measure is necessary when the content of high-reactivity substances in the bottoms product from the third column 9 would be too high to run said product directly into the dehydrogenation 17 . However, such a procedure is not preferred.
LIST OF REFERENCE SYMBOLS
1 Feedstock mixture
2 Recyclate
3 Feed
4 Hydroformylation
5 Synthesis gas
6 Hydroformylation mixture
7 First column
8 Second column
9 Third column
10 Tops product from first column
11 Bottoms product from first column
12 Primary product fraction
13 Tops product from second column
14 Low boiler fraction
15 Subsidiary fraction
16 First heat exchanger
17 Dehydrogenation
18 Oxygen
19 Dehydrogenation mixture
20 First compressor stage
21 Second heat exchanger
22 Circuit
23 Second compressor stage
24 Selective hydrogenation
25 Hydrogen
26 Carbon monoxide
27 Hydrogenation mixture
28 Fourth column
29 Secondary product fraction
30 Tops product from fourth column
31 Hydrogenation | The invention is concerned with the issue of how to produce n-pentanal by hydroformylation from feedstock mixtures comprising a small proportion of n-butene and a large proportion of n-butane. Specifically, solutions for further optimizing established processes for hydroformylation of such low-butene mixtures in terms of material utilization are sought. The present invention has for its object to enhance the material utilization of the feedstock mixture in the production of n-pentanal from feedstock mixtures having a small proportion of n-butene and a large proportion of n-butane. The process shall be capable of economic operation on an industrial scale. In particular an existing oxo plant shall be honed to achieve better raw material utilization. This object is achieved by a combination of a hydroformylation and a dehydrogenation, wherein said combination has the special feature that the dehydrogenation is arranged after the hydroformylation in the downstream direction and is thus markedly smaller than conventional dehydrogenations provided upstream. A skillful product removal effectively removes contaminants formed in the process. | 2 |
BACKGROUND OF THE DISCLOSURE
The present invention relates to a numerical control unit, and in particular to a numerically controlled machine tool which enables more efficient positioning of an interchangeable tool at a tool changing position.
FIG. 8, which is a block diagram of positioning apparatus for achieving a tool changing position in a known numerical control unit, shows a machining program 1, a reader 2 for reading a machining program 1, a key input device 3 for entering a machining program from its keyboard, a machining program editor 4 for writing the machining program in accordance with data entered from the keyboard, a machining program file 5 for storing the machining program written by the machining program reader 2 or the machining program editor 4, a one-block reader 6 for extracting and reading one block from the machining program, a command analyzer 7 for interpreting the command in the block and performing processing such as an operation in accordance with that command, a move command generator 8 for defining the travel of each control axis in accordance with the results of the command analyzer 7, a drive controller 9 for converting a move command into an electrical signal, and a servo motor 10 for driving each control axis. A current position storing device 11 accumulates a current position updated and managed by the move command generating device 8. A key input device 12 enters data such as a tool length. A tool data memory 13 accumulates data such as tool length. A key input device 14 teaches a tool changing position. A tool changing position defining device 15 defines the tool changing position in accordance with the tool data stored in the tool data memory 13 and a teaching command provided by the key input device 14, and a tool changing position memory 16 accumulates the defined tool changing position.
FIG. 9 illustrates relationships among a workpiece, a machine tool and a tool, including a chuck 87 of the machine tool for gripping a workpiece 86, and a tool rest 85 of the machine tool, movable in Z-axis and X-axis directions, and rotatable for making a tool change. First to fourth tools 81-84 are installed in tool rest 85 and are assigned respective tool numbers T00. "A" indicates a reference point, and "B" a current position at the time of teaching, as contained in the current position memory 11 and located a distance AX T from the reference point A. "C" indicates a tool changing position stored in the tool changing position memory 16 and located a vertical distance TC away from the reference point A.
Operation will now be described with reference to FIGS. 8 and 9. Lengths TL1 to TL4 of the tools 81 to 84 mounted on the tool rest 85 are registered beforehand in the tool data memory 13 from the key input device 12 in correspondence with the tool numbers. After selecting any tool, the tool is positioned manually to a tool changing position where the tool does not interfere with the workpiece 86, the machine chuck 87 and the like, using a jogging function or the like intrinsic to the machine tool. Then, the numerical control unit is taught the tool changing position using the key input device 14. The tool changing position defining device 15 extracts the length TL N of the tool 81 currently selected, and also the maximum tool length TL MAX among those of the registered tools from the tool data memory 13. The defining device 15 then extracts the teaching-time current position B from the current position storing device 11, obtains the tool changing position C according to the expression TC=AX T -(TL MAX -TL N ), and stores the result into the tool changing position memory 16.
When automatic operation is to be performed, one program block is fetched by the one-block reader 6 from the machining program stored in the machining program file 5. The command analyzer 7 interprets the one block, extracts the coordinates of the tool changing position C from the tool changing position memory 16 if a tool positioning command (e.g., G24, G25, G26, G27) exists in that one block, or generates the positioning command for the tool changing position C.
The move command generator 8 obtains the amount of travel in accordance with the current position in the current position memory 11 and the target end-point position, i.e., tool changing position C, and gives it to the drive controller 9 as a move command. The drive controller 9 converts the position command into an electrical signal to drive the servo motor 10, and runs the servo motor 10 until the target end-point position, i.e., tool changing position C, is reached, to complete positioning to the tool changing position C.
In the known numerical control unit configured as described above, the tool changing position C is a fixed position defined in accordance with the longest tool 84 and the teaching-time workpiece state. This may cause the tool changing position C to be located further away from the workpiece 86 than required, which results in a disadvantage of longer overall machining time. It is desirable to reduce the machining time by making the tool changing position C variable to provide the optimum tool changing position.
FIG. 4 shows machining in which point E indicates a non-interfering tool changing position before machining (the workpiece is indicated by a continuous line), which is defined by the conventional numerical control unit, and point D indicates a non-interfering optimum tool changing position after some machining has been performed (the workpiece is indicated by a broken line). Thus, the tool need not move as far to be in a safe tool changing position. It would be desirable to be able to change the tool at a closer tool changing position, to save time.
SUMMARY OF THE INVENTION
Accordingly, it is an object of the present invention to overcome the disadvantages in the conventional devices by providing a numerical control unit which ensures ease of positioning to the optimum tool changing position every time positioning is performed.
A numerical control unit according to a first embodiment of the invention is equipped with a tool changing position storing mode processor which stops the execution of a machining program when a positioning command for tool changing is given by the machining program during execution of the program in a tool changing position storing (teaching) mode.
A numerical control unit according to a second embodiment of the invention is equipped with a tool changing position memory and a tool changing position editor. The tool changing position editor adds tool changing position data, stored in the tool changing position memory, to a machining program.
A numerical control unit according to a third embodiment of the invention is equipped with a tool changing position memory and a tool changing position storing processor. The tool changing position storing processor stores tool changing position data, in a machining program, at predetermined addresses of the tool changing position memory when a tool changing position setting command is given by the machining program.
The numerical control unit according to the first embodiment of the invention allows the optimum tool changing position to be re-defined by the tool changing position storing mode processor which stops execution of the machining program in a teaching mode.
The numerical control units according to the second and third embodiments prevent the defined tool changing position data from being lost, by means of a tool changing position editor which adds the tool changing position data, stored in the tool changing position memory, into the machining program, and by means of a tool changing position storing processor which takes the tool changing position data from the machining program and enters it in the tool changing position storing device, respectively.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram of a first embodiment of the present invention.
FIG. 2 is a flowchart illustrating the operation of a tool changing position storing mode processor according to the first embodiment of the invention.
FIG. 3 is a flowchart showing the operation of an ordinary operation mode processor according to the first embodiment of the invention.
FIG. 4 illustrates how the optimum tool changing position is defined according to a first embodiment of the invention.
FIG. 5 is a block diagram of the second and third embodiments of the invention.
FIG. 6 is a flowchart illustrating the operation of a tool changing position editor according to the second and third embodiments of the invention.
FIG. 7 is a flowchart showing the operation of a tool changing position storing processor according to the second and third embodiments of the invention.
FIG. 8 is a block diagram of a known numerical control unit.
FIG. 9 illustrates a conventional tool changing position storing procedure.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
A first embodiment of the present invention will now be described with reference to FIGS. 1 to 4. In FIG. 1, numerals identical to those in the block diagram of FIG. 8 identify identical parts, and therefore will not be further described. The numerical control unit includes an operation mode determining element 17a in the command analyzing device 7, a tool changing position storing mode processor 17b in the command analyzer 7, an ordinary operation mode processor 17c, an improved tool changing position defining device 15, and a memory 16a for storing multiple tool changing positions corresponding to the positioning commands for the tool changing positions.
Operation of this embodiment now will be described. Before machining is initialized, the lengths TL1 to TL4 of the tools 81 to 84 installed in the tool rest 85 are registered, via the key input device 12, into the tool data storing memory 13 in correspondence with the tool numbers.
Meanwhile, a machining program 1, including positioning commands (e.g., G24, G25, G26, G27) for, e.g., the tool changing positions, is written into the machining program file 5 from the machining program reader 2, or from the key input device 3 by the machining program editor 4.
Before starting the first machining operation, tool offset data, machining programs, etc., are written as described above, and a tool changing position storing mode is selected.
The tool changing position storing mode is selected from the key input device 3, or by a switch, etc. (not shown). When automatic operation is to be performed, one block of the machining program is read by the one-block reader 6 in either the tool changing position storing mode or the ordinary operation mode. Since the tool changing position storing mode has been selected for the first run, the mode determining element 17a of the command analyzer 7 determines the operation mode as the tool changing position storing mode, and causes the tool changing position storing mode processor 17b to be operated. As shown in the flowchart in FIG. 2, this processing determines whether the command provided is a positioning command for tool changing (step 1). When it is, the processor stops processing the block without any operation, like a program stop, using the M00 command, and assumes a state which allows processing of the block to be resumed at the next start (step 2). When the command is not such a positioning command, processing is performed corresponding to the command in the same manner as in the conventional system (step 3). The operation of the move command generator 8 and downstream elements is identical to that in the conventional system, and the servo motor 10 is driven according to the command.
When processing is stopped when the positioning command for the tool changing position is encountered in the tool changing position storing mode, the machine operator moves the tool rest 85 manually to the optimum tool changing position, using the jogging function or the like intrinsic to the unit, and teaches the numerical control unit the optimum tool changing position from the key input device 14.
The details of this operation will now will be described with reference to FIG. 4. Assuming that the workpiece 86, configured as indicated by the continuous line before machining, has so far been cut into a shape indicated by the broken line, the position of the tool rest 85 where the tool does not interfere with the workpiece 86, the machine chuck 87, etc., before machining is at position E. Since the workpiece 86 has been cut into the shape indicated by the broken line, the operator moves the tool rest 85 manually to position D as the non-interfering optimum tool changing position and teaches the numerical control unit the optimum tool changing position from the keyboard This allows position D of the tool rest 85 to be registered as the tool changing position after the progress of machining, in addition to position E which could only be used before machining.
When the optimum tool changing position signal is provided from the keyboard, the tool changing position defining device 15a extracts the current position from the current position memory 11 and stores it in the multiple-tool changing position memory 16a. This operation is repeated until no positioning commands for tool changing positions remain in the machining program, and the tool changing position data is stored into the multiple-tool changing position memory 16a in order of storage.
To continue the same machining as described above, the operation mode is set to the ordinary operation mode. At this time, the mode determining circuit 17a determines the operation mode as the ordinary operation mode and causes the ordinary operation mode processor 17c of the command analyzer 7 to be operated. As shown in the flowchart in FIG. 3, this processing determines whether the command given is a positioning command for the tool changing position (step 11). When it is, the next tool changing position, stored as described previously, is read from the multiple-tool changing position memory 16a (step 12). Positioning command data which defines the corresponding position as an end point is output (step 13). The reference pointer then is incremented by one to read the next tool changing position when the positioning command for the next tool changing position is provided (step 14).
Upon reaching the position of an end code (generally 0), the reference pointer returns to the first position. When the command provided is not a positioning command, operations, etc., corresponding to the command are performed in the same manner as in the conventional system (step 15).
In this first embodiment of the invention, a block stop, effected without any operation on the positioning command for the tool changing position in the tool changing position storing mode, may be made after positioning has been effected for a specific or a preceding tool changing position. In this case, the machine comes to a stop without putting the tool into contact with the workpiece so that cutter marks are not made on the workpiece.
When there is only one multiple-tool changing position memory 16a as in this embodiment, the same multiple-tool changing position memory 16a must be used for both first machining and second (or subsequent) machining operations which have different tool changing positions. Hence, the optimum tool changing positions for the first machining operation stored in the memory 16a as described above will be cleared by the tool changing positions for the second machining operation.
In this case, the tool changing positions must be redefined for the first machining operation if the first machining operation is performed again after the second machining operation. This manner of operation causes difficulty and inconvenience This problem can be solved by providing a multiple-tool changing position memory 16a for each machining program and managing the memories 16a and programs in correspondence with each other. However, this increases the necessary memory capacity, and it is very troublesome to manage the memories 16a and the machining programs in correspondence with each other.
These disadvantages can be overcome according to further embodiments of the invention by defining the tool changing position not from the key input device 14, but from the machining program. The second and third embodiments illustrated in FIGS. 5 to 7 are designed to achieve this end.
Referring to FIG. 5, a key input device 21 controls commands for editing the tool changing position of the multiple-tool changing position memory 16a in the machining program as a tool changing position setting command. Editor 22 generates the tool changing position according to the command given from the keyboard. A command determining area 17d of the command analyzer 7 differentiates between the tool changing position setting command and said other commands, and a processor 17e of the command analyzer 7 stores the tool changing position according to the tool changing position setting command. The other parts are identical to those of the first embodiment, and will not be described.
The operation of the second embodiment now will be described. When a second machining operation, having different tool changing positions from the first machining operation, is to be performed after the first machining operation, a command to start editing the tool changing position setting commands is output from the key input device 21. The machining program for the first machining operation is at this time stored in the machining program file 5. The aforementioned command causes the tool changing position editor 22 to be operated. As shown in a flowchart in FIG. 6, this processing extracts the coordinates of a tool changing position from the multiple-tool changing position memory 16a, converts it into the form of a machining program block in ISO code (or EIA code) in accordance with the setting command format, and adds it to the beginning of the machining program. The processing is complete when all coordinates registered in the multiple-tool changing position memory 16a have been converted.
In this embodiment, "G11" is specified as a tool changing position setting command code, the number of the tool changing position is specified by a value following L, and the coordinate values of the X and Z axes for the tool change point are specified by values following X and Z, respectively.
Specifically, as shown in FIG. 6, the L number is set to an initial value and the reference pointer of the multiple-tool changing position memory 16a is set at the beginning (step 21). The L number is then converted into ISO code (or EIA code) and stored into the L number position of the character string "G11L X Z . . . EB" (step 22). One tool changing coordinate then is fetched, converted into ISO (or EIA) code, and stored in the X position of the character string (step 23). The other tool changing coordinate then is fetched, converted into ISO (or EIA) code, and stored in the Z position of the character string (step 24). The entire data of the character string, which resides in a buffer, thus having stored the L number and the X and Z Coordinate values, is added to the beginning of the machining program (step 25).
The operation of steps 22 to 25 is repeated until the end code is read from the multiple-tool changing position memory 16a (step 26), and the addition of the tool changing positions to the machining program is made in order of reading the tool changing positions. When the end code is read from the tool changing position memory 16a (step 26), the transfer of the tool changing positions from the multiple-tool changing position memory 16a to the machining program is completed.
During a run, the one-block reader 6 reads the machining program on a block-by-block basis from the machining program file 5, and when the "G11" command is recognized by the command determining area 17d, the tool changing position storing processor 17e is operated. As shown in the flowchart in FIG. 7, this processing is performed in the reverse manner from the operation performed by the tool changing position editor 22. That is, when the "G11" command stored at the beginning of the machining program is recognized, the storage pointer of the multiple-tool changing position memory 16a is set in accordance with the number of the tool changing position known from the value following L (step 31). The value following X then is converted into binary form and is stored in the corresponding pointer-indicated place in the multiple-tool changing position memory 16a (step 32). The value following Z then is converted into binary form and is stored in the corresponding pointer-indicated place in the multiple-tool changing position memory 16a (step 33). The operation of steps 31 to 33 is repeated until there are no "G11" commands stored at the beginning of the machining program. The tool changing position storing processor 17e operates as described above.
When the command provided is not a tool changing position setting command, the ordinary operation mode processor 17c of the command analyzer 7 is operated. After the tool changing positions thus have been stored from the machining program in the multiple-tool changing position memory 16a, providing the position command for the tool changing position causes the tool changing positions to be read from the multiple-tool changing position memory 16a in order and the positioning command data defining the corresponding position as an end point to be output, as in the first embodiment.
The second embodiment of the invention, further improving the first embodiment, may be applicable not only to the first embodiment but also to conventional systems or the like described with reference to FIGS. 8 and 9, so long as a first machining operation is to be performed a second time after a second machining operation which has different tool changing positions. In this manner, the tool changing positions of the first machining operation need not be redefined each time.
The second embodiment of the invention as described above re-stores the tool changing positions from the machining program into the multiple-tool changing position memory 16a during the next run of the program. However, this embodiment may have its command format changed to allow the tool changing positions to be commanded directly from the machining program, without re-storing them into the multiple-tool changing position memory 16a being necessary.
While the third embodiment has been described as an adjunct executed after the second embodiment (i.e., after tool changing positions stored in the memory have been encoded and stored in the machining program), such need not be the case. The third embodiment allows one to write beforehand a machining program including encoded tool changing positions, thus allowing the required tool changing positions to be specified directly from the machining program without use of the second embodiment.
It will be apparent that the invention, as described above, achieves a numerical control unit which during a teaching mode stops operation every time a positioning command for the tool changing position is given, so that the operator can teach the optimum tool changing position, allowing the positioning distance to be reduced by a simple operation and the machining time to be minimized.
The invention further allows the contents of the tool changing position memory to be added to the machining program as tool changing position setting commands. Also, the tool changing positions may be set in the tool changing position memory from the machining program, so that tool changing positions corresponding to various machining programs can be used repeatedly without being redefined, thereby reducing the length of time required to prepare for machining.
While the invention has been described in detail above with reference to preferred embodiments, various modifications within the scope and spirit of the invention will be apparent to people of working skill in this technological field. Thus, the invention should be considered as limited only by the scope of the appended claims. | A "safe" position for a tool changing operation in a numerically controlled machine tool is determined based on specific tool size and machining location. In one embodiment, tool change positions are taught in a teaching operation, and are stored for future reference. During machining, as each tool changing position is encountered, a pointer has advanced to the next such position so that, upon execution of the next tool changing command, the unit moves to the appropriate location. According to other embodiments, the machining program itself is made to store the tool changing positions. This data may be added to the program by an editor on the basis of the information found in the memory, or the data may be added in the initial creation of the program. The data on tool changing positions is then decoded from the machining program when the program is read or executed. | 8 |
TECHNICAL FIELD
The present invention relates to systems and methods for a unique form of competition or contests in the sport of fishing and hunting.
BACKGROUND OF THE INVENTION
A sport is an organized, competitive, entertaining, and skillful activity requiring commitment, strategy, and fair play, in which a winner can be defined by objective means. Generally speaking, a sport is a game based in physical athleticism.
Sports and sporting competitions are governed by a set of rules or customs. Physical events such as scoring goals or crossing a line first often define the result of a sporting competition. However, the degree of skill and performance in some sports, such as diving, dressage and figure skating, is judged according to well-defined criteria.
There are artifacts and structures that suggest that the Chinese engaged in sporting activities as early as 2000 BC. Traces of the earliest sports activities, such as hunting, archery and rowing race, can be seen from some bronze ware of the late Neolithic Age as well as from other articles. For example, artifacts such as a lacquered wooden comb of the Qin Dynasty (221-206 BC) feature an ancient Chinese sports activity called “jiaodi.” Of early origin, it is a game similar to wrestling of modern times. The ancient “jiaodi” was performed by athletes wearing ox horns and wrestling with each other imitating wild oxen. Various sports activities can be found in historic expressions such as mural paintings, stone paintings, brick paintings, pottery figurines and poems.
Monuments to the Pharaohs indicate that a number of sports, including swimming and fishing, were well-developed and regulated several thousands of years ago in ancient Egypt. Other Egyptian sports included javelin throwing, high jump, and wrestling. Ancient Persian sports such as the traditional Iranian martial art of Zourkhaneh had a close connection to the warfare skills. Among other sports that originate in ancient Persia are polo and jousting.
A wide range of sports were already established by the time of Ancient Greece and the military culture and the development of sports in Greece influenced one another considerably. Sports became such a prominent part of their culture that the Greeks created the Olympic Games, which in ancient times were held every four years in a small village in the Peloponnesus called Olympia.
Sports have been increasingly organized and regulated from the time of the ancient Olympics up to the present century. Industrialization has brought increased leisure time to the citizens of developed and developing countries, leading to more time for citizens to attend and follow spectator sports, greater participation in athletic activities, and increased accessibility. These trends continued with the advent of mass media and global communication. Professionalism became prevalent, further adding to the increase in sport's popularity, as sports fans began following the exploits of professional athletes through radio, television, and the internet—all while enjoying the exercise and competition associated with amateur participation in sports.
Records are kept and updated for most sports at the highest levels, while failures and accomplishments are widely publicized in sport news. While conduct may vary, sports participants are expected to display good sportsmanship, and observe standards of conduct such as being respectful of opponents and officials, and congratulating the winner when losing.
Modern fishing contests or tournaments are common recreational competitions on lakes, bays, rivers and larger saltwater bodies, generally focusing on the number of fish of a specific species caught or the weight (combined or otherwise) of the fish caught, during a specific time period on a single body of water.
As well as being a form of recreation for the participants, much sport is played in front of an audience. Most professional sport is played in a theatre of some kind; be it a stadium, arena, golf course, race track, or the open road, with provision for the (often paying) public. Large television or radio audiences are also commonly attracted, with rival broadcasters bidding large amounts of money for the rights to show certain fixtures.
The football World Cup attracts a global television audience of hundreds of millions; the 2006 final alone attracted an estimated worldwide audience of well over 700 million. The Cricket World Cup is another sporting event which attracts a global audience. The 2007 Cricket World Cup attracted about 2.3 Billion viewers all over the world. In the United States, the championship game of the NFL, the Super Bowl, has become one of the most watched television broadcasts of the year. Super Bowl Sunday is a de facto national holiday in America; the viewership being so great that in 2007 advertising space was reported as being sold at $2.6 m for a 30 second slot.
SUMMARY OF THE INVENTION
There are a number of advantages of the proposed and preferred system and method for conducting an endurance competition or contest (e.g. hunting or fishing competition) with event-based intermediate stages. Specifically, the present invention conducts the sporting competition by keeping track of, monitoring, and regulating an endurance sporting competition through its various intermediate event-based stages. The sporting competition will require the participants to demonstrate a multitude of skills, along with a certain amount of the “luck of the catch” at the various intermediate stages. The participant has to complete a task or tasks at each stage in the competition prior to proceeding to the next stage, and ultimately, to finish the race. The present invention conducts, monitors, and regulates the sporting-event that takes place over an extended geographic area, during an extended time period, with intermediate event-based stages occurring before arriving at the finish line.
In comparison to existing sporting competitions that only test the abilities of the contestants to perform a certain activity (e.g., catch as many largemouth bass as possible) in a single environment (e.g., a single lake) in a predetermined period of time (e.g., four hour period), the proposed competition is much broader in scope and its requirements. In a fishing competition, the proposed contest system may vary both the type and the size of fish sought as well as the location over which the fish must be caught. In addition, the time period may be extended or shortened, so that the contestant must catch the fish in a certain time period (e.g., 24 hours) or all of the fish in a combined time period (e.g., 7 days) or be disqualified or disadvantaged in some manner.
Awards and/or prizes may be awarded for First, Second, Third, or any other place that completes the tasks and makes it to the finish. Consequently, the proposed contest system requires competing participants to not only display superior skill and “luck of the catch,” but to also engage in a test of endurance—testing physical stamina and the durability of their equipment.
The proposed contest system is an event-driven event with an endurance component. In one embodiment, the system would combine a fishing tournament and a first-to-the-finish line race. Existing fishing competitions are very similar to one another, with minor differences in the specific fish targeted, the location of the contest, the methodology for scoring the recorded catches, and the methodology for ranking and awarding winners of the contest. The proposed contest system would support a more challenging, complex and interesting competition to the contestants as well as to the spectators. Because of its unique and variable aspects, a unique system is needed to account, monitor and support the competition.
The proposed invention is a system and/or method that conducts a sporting competition that does not focus on the quantity of scoring (e.g. recorded catches in fishing competition) during a predetermined time period, but rather on a race to a finish line over an extended distance (without or without planned stops) where each intermediate stage requires completing particular tasks to qualify for progressing to the next stage of the race. The outcome of the contest may be decided, primarily, on who finishes the predetermined course in the shortest amount of time or on accumulated point totals that are tallied by the system. To finish, a contestant, or team of contestants, must have accomplished a task or set of tasks at each intermediate stage (e.g. recorded the required catches) for each of the designated segments along the course route of the contest. In that way, the present invention will conduct an endurance race that is more akin to marathon foot race with intermediate event-based stages, as opposed to a modern fishing competition.
BRIEF DESCRIPTION OF THE DRAWINGS
The novel features believed characteristic of the invention are set forth in the appended claims. The invention itself, however, as well as preferred modes of use, further objectives, and advantages thereof, will be best understood by reference to the following detailed description of illustrative embodiments when read in conjunction with the accompanying drawings, wherein:
FIG. 1 is a system configuration illustrating the components and system interconnections for input information in the present invention,
FIG. 2 is a system configuration illustrating the components and system interconnections for output information in the present invention,
FIGS. 3 a and 3 b are system configurations illustrating the components and system interconnections for event monitoring and display information in the present invention, including the monitoring equipment used at various stages in the competition,
FIG. 4 is a flow-chart showing the steps involved with conducting the endurance sporting event with intermediate event-based steps,
FIG. 5 is a flow-chart showing the monitoring of various activities that occur in the endurance sporting competition,
FIG. 6 is a flow chart illustrating the process that competing fishermen would follow in competing in the contest on an example Saltwater contest course, such as that shown in FIG. 2 .
FIG. 7 is a flow chart illustrating the timeline of an example contest held along the Texas Coastal bay systems, running from Sabine Pass on the far east edge of the Texas coast, down to Port Isabel on the southern tip of the Texas coast.
FIG. 8 is a map providing an example of a course from start to finish through the bay systems along the Texas Coast, indicating the starting point, each of seven exemplary stage areas 302 , 305 , 307 , 309 , 311 , 313 , and 315 , each of seven stage area recording stations 303 , 306 , 308 , 310 , 312 , 314 , and 316 , if the example contest used recording stations to record qualifying catches, and finishing point 316 of the contest.
FIG. 9 is a map providing an example of a course from start to finish through a River (riparian) Freshwater Contest Course, in this illustration, the example of a contest held on the Mississippi River, from Minneapolis-St. Paul to New Orleans.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
In FIG. 1 , the information input components and system interconnection 10 a are shown with the computer-based system 11 being coupled to an input-output device 12 via connection 13 , workstation WS 1 15 via connection 14 , workstation WS 2 17 via connection 16 , workstation WS 3 19 via connection 18 , and a memory database 21 via connection 20 . Information input into the system 11 can be captured and received by the parts of the system 10 a shown in FIG. 1 . The computer-based system 11 has a central processing unit, memory, and ports for supporting input/output connections. The computer-based system 11 is coupled to an interface 22 via connection 23 , and the interface is coupled to a gateway 25 via connection 24 and a telephone switch 26 via a connection 27 . The telephone switch 26 is coupled to the gateway 25 via connection 56 . The gateway 25 is coupled to the Internet 31 via connection 30 , and the telephone switch 26 is coupled to a telephone network 34 via connection 29 .
A mobile unit 48 associated with a participant in the competition or that participant's vehicle is coupled by a radio signal 49 to a radio access network antenna 42 . The mobile unit 48 can transmit information from the participant includes event-based information, completion of tasks, photo documentation of task completion, location information or other information about the progress of the participant in the competition. The format of these transmissions can be electronic mail, text messages, instant messaging, or uploading of information onto the computer system 11 , social network site or applications program devoted to the participant or the sporting competition. The mobile unit 48 is coupled to the participant vehicle 51 via connection 50 , and a GPS (global positioning satellite) unit 53 . The GPS unit 53 obtains positioning satellite signals from several geosynchronous satellite(s) 54 in order to calculate positioning and location information. This positioning and location information is transmitted to the system 11 via radio transmission 55 or through the radio transmission 49 through the mobile unit 48 .
The progress of the competition can be monitored by the monitor input unit 46 , which can be coupled to the computer system 11 via the connection 43 and 28 . Alternatively, the information input into the monitor input unit 46 can be transmitted to the computer system via the telephone network using connection 43 , 36 and 37 , or the Internet 31 connection via connection 43 , 36 and 32 . Also, the information input into the monitor input unit 46 can be transmitted to the computer system 11 via a radio transmission 47 through the radio access network 42 and 40 , and through the telephone network 34 or the Internet network 31 . The information input into the monitor can be input by a participant, an observer, or a judge associate with the competition.
The progress of the competition can be visually recorded or provided in real-time by video unit 44 , which can be coupled to the computer system via connection 28 . Alternatively, the information input into the monitor input unit 46 can be transmitted to the computer system via the telephone network using connection 43 , 36 and 37 , or the Internet 31 connection via connection 43 , 36 and 32 . Also, the information input into the monitor input unit 46 can be transmitted to the computer system 11 via a radio transmission 47 through the radio access network 42 and 40 , and through the telephone network 34 or the Internet network 31 . The information input into the monitor can be input by a participant, an observer, or a judge associate with the competition.
The radio access network includes radio access network antenna 42 coupled to a substation switch SS 40 via connection 41 . The substation switch SS 40 is coupled to the gateway GW 39 via connection 38 . The substation switch SS is coupled to a telephone network 34 via connection 35 or the Internet 31 via connection 37 and 33 . The gateway is coupled to the Internet 31 via connection 32 .
In FIG. 2 , the system components and interconnections 10 b associated with information output are shown with system 11 being coupled to an input-output device 12 via connection 13 , workstation WS 1 15 via connection 14 , workstation WS 2 17 via connection 16 , workstation WS 3 19 via connection 18 , and a memory database 21 via connection 20 . Information input into the system 11 can be captured and received by the parts of the system 10 a shown in FIG. 1 . The computer-based system 11 has a central processing unit, memory, and ports for supporting input/output connections. The computer-based system 11 is coupled to an interface 22 via connection 23 , and the interface is coupled to a gateway 25 via connection 24 and a telephone switch 26 via a connection 27 . The information output from the computer system regarding the progress of the participants in the competition can be transmitted and displayed by the parts of the system 10 b shown in FIG. 2 . Moreover, all this information may be transferred to a television or cable provider server for broadcasting the competition in real-time, on a tape-delayed basis, or in an on-demand basis.
The computer-based system 11 is coupled to the gateway 25 via connection 28 and the broadcast interface station 78 b via connection 78 a . The broadcast interface station 78 b is coupled to the gateway 25 via connection 56 . The broadcast interface station 78 b is coupled to a television/video network system 58 via connection 57 . The television/video network system 58 is coupled to the Internet 59 a via connection 59 .
The television/video network 58 is coupled to various broadcast or display units via connection 72 . These display units include, for example, a television 76 , video display 73 , high definition television/video display TD 75 , and real-time pay-per-view displays 74 . These monitors and displays will receive and display video and television video and sound coverage of the competition in real-time or as previously recorded. The previously recorded video and sound presentations will be maintained and deposited for future use on the computer-based system 11 working in conjunction with database memory 21 .
The Internet 59 a is coupled to web-based and mobile Internet Protocol (IP) access components via connection 60 . The mobile IP and web-based components coupled to connection 60 include remotely-coupled devices such as a computer 61 , a smart monitor screen display 62 , or a smart mobile phone device SC 63 . The connection 60 may also link the Internet 59 a to a gateway 64 , which is coupled to a radio access network substitution SS 66 .
The network substation SS 66 is coupled to a remote access network antenna 68 via connection 67 . The antenna 68 is coupled via wireless radio electronic connection 69 to one or more mobile units 70 a , 70 b , and/or 70 c . These display and computer devices may also be coupled to the computer-based system 11 through a telephone system such as that shown at 34 in FIG. 1 .
All of these mobile units 70 a , 70 b , 70 c and remotely coupled computers 61 and 63 and monitors are capable of display web pages maintained and updated by the computer system 11 regarding the progress of the competition, real-time video of the present or past competitions, stored video coverage of the competition, participants in the present or past competitions, re-plays of video presentations or television shows based on the present or past competition, statistics/standing of past and present competitions, profiles of the participants, interviews and news reports regarding the competition or its participants, and links to related websites or sponsors' websites. The website information displayed on these devices will be prepared, maintained, and deposited in the computer-based system 11 working in cooperation with the database memory 21 and workstations WS 1 15 , WS 2 17 , and WS 3 19 .
In FIG. 3 a , the monitoring system components and interconnections are shown. The computer-based system 11 is coupled to database memory 21 via connection 21 , to an input-output unit 132 via connection 13 , and to workstations WS 1 15 , WS 2 17 , and WS 3 19 via connections 14 , 16 and 18 , respectively. The computer-based system 11 is also coupled to a display 84 that can display information retrieved from computer-based system 11 via connection 82 . The computer-based system 11 is also coupled to a monitor work station 77 via connection 77 for remote access to the computer-based system 11 . The interface 22 is also coupled to a gateway 25 network via connection 24 and a telephone network switch 26 via connection 27 .
The competition and progress of the participants can be monitored by the monitor workstation 77 , the video and television cameras VF 1 86 , VF 2 87 , VF 3 88 , VF n 89 and mobile units MV 1 48 a , MV 2 48 b , and MV 3 48 c . The video and television cameras 86 - 89 can record actual footage of the competition participants for real-time play-back through the computer-based system 11 to spectators and observers using the output devices disclosed and described in FIG. 2 . The spectators can select which video or television footage to watch by selecting the particular video feed component VF 1 , VF 2 , VF 3 , to VF n to receive footage. The footage can be real-time or deposited in the computer-based system 11 and its database memory 21 for viewing at a later time.
The video and television feed cameras VF 1 86 , VF 2 87 , VF 3 88 , and VF n 89 are coupled to the interface 22 via connection 88 . These devices may also be connected to the telephone switch 34 via connections 90 and 91 or the internet 31 via connection 90 . The mobile units MV 1 48 a , MV 2 48 b , and MV 3 48 c are coupled to the computer-based system 11 through a radio access network 40 , which is coupled to the mobile units 48 a to 48 c via connection 49 . The radio access network 40 is coupled to the telephone network 34 through connection 35 , and is coupled to a gateway 39 via connection 39 a . The radio access network 40 is also coupled to the computer-based system 11 via connections 35 , 83 and 82 .
The gateway is coupled to the Internet 31 via connection 32 , and the Internet is coupled to the gateway 25 via connection 30 and the computer-based system 11 via connections 81 and 82 . The telephone network 34 is coupled to the telephone switch 26 via connection 29 . These interfaces and interconnections all provide communication support for coupling the monitoring devices MON 77 , MV 1 to MV n ( 48 a to 48 c ) and video and television feed cameras VF 1 86 to VF n 89 .
In FIG. 3 b , various monitoring equipment is shown at various stages in the competition. For instance, the Start Stage 2000 is shown next to Intermediate Stage 2050 , the Intermediate Stage 2 2075 , then Intermediate Stage 3 2100 , and the Finish Stage 2150 . For the Start Stage 2000 , there is an input monitor workstation shown at 2005 that is coupled to the computer-based system 11 and the video/television feed cameras VF 1 2010 to VF n 2015 that provide video and sound feeds to the computer-based system 11 . A large display 2020 for spectators is also located at the Start Stage, which is also coupled to the computer-based system 11 . The coupling of these monitor and display components to the computer-based system 11 comports with the interconnections described in FIGS. 1 , 2 and 3 a.
At Intermediate Stage 1 2050 , the participant PA 1 2058 is monitored by video feed camera VF 1 2051 , which provides feed video to the computer-based system 11 . At Intermediate Stage 1 2050 , the participant PA 2 2057 is monitored by video feed camera VF 2 2052 , which provides feed video to the computer-based system 11 . At Intermediate Stage 1 2050 , the participant PA 3 2056 is monitored by video feed camera VF 3 2053 , which provides feed video to the computer-based system 11 . At Intermediate Stage 1 2050 , the participant PA n 2055 is monitored by video feed camera VF n 2054 , which provides feed video to the computer-based system 11 . A monitor workstation M 2005 a is also located at the Intermediate Stage 1, and provides information and input regarding the progress of the contestants in the competition at Stage 1 2050 to the computer-based system 11 . These components are coupled to the computer-based system 11 in the designated in FIGS. 1 , 2 and 3 a.
At Intermediate Stage 2 2075 , the participant PA 1 2080 is monitored by video feed camera VF 1 2076 , which provides feed video to the computer-based system 11 . At Intermediate Stage 2 2075 , the participant PA 2 2081 is monitored by video feed camera VF 2 2077 , which provides feed video to the computer-based system 11 . At Intermediate Stage 2 2075 , the participant PA 3 2082 is monitored by video feed camera VF 3 2078 , which provides feed video to the computer-based system 11 . At Intermediate Stage 2 2075 , the participant PA n 2083 is monitored by video feed camera VF n 2079 , which provides feed video to the computer-based system 11 . A monitor workstation M 2005 b is also located at the Intermediate Stage 2, and provides information and input regarding the progress of the contestants in the competition at Stage 2 2075 to the computer-based system 11 . These components are coupled to the computer-based system 11 in the designated in FIGS. 1 , 2 and 3 a.
At Intermediate Stage 3 2100 , the participant PA 1 2101 is monitored by video feed camera VF 1 2105 , which provides feed video to the computer-based system 11 . At Intermediate Stage 3 2100 , the participant PA 2 2102 is monitored by video feed camera VF 2 2106 , which provides feed video to the computer-based system 11 . At Intermediate Stage 3 2100 , the participant PA 3 2103 is monitored by video feed camera VF 3 2107 , which provides feed video to the computer-based system 11 . At Intermediate Stage 3 2100 , the participant PA n 2104 is monitored by video feed camera VF n 2108 , which provides feed video to the computer-based system 11 . A monitor workstation M 2005 c is also located at the Intermediate Stage 3, and provides information and input regarding the progress of the contestants in the competition at Stage 3 2100 to the computer-based system 11 . These components are coupled to the computer-based system 11 in the designated in FIGS. 1 , 2 and 3 a.
For the Finish Stage 2150 , there is an input monitor workstation shown at MON 2151 that is coupled to the computer-based system 11 and the video/television feed cameras VF 1 2152 to VF n 2153 that provide video and sound feeds to the computer-based system 11 . A large display 2154 for spectators is also located at the Start Stage, which is also coupled to the computer-based system 11 . The coupling of these monitor and display components to the computer-based system 11 comports with the interconnections described in FIGS. 1 , 2 and 3 a.
In FIG. 4 , the processing program steps conducted by the computer-based system 11 are shown starting at the Start Step 1000 . From Step 1000 , the process flow proceeds to Step 1002 by Step progression 1001 . The Step 1002 records that the participant is entering the next Intermediate Stage. After step 1002 , the program proceeds to inquiry 1004 at step progression 1003 .
Moreover, the participant may have a flag pole on its vehicle or other indicator of tasks completed, which should remain unchanged until the next task is completed. At inquiry 1004 , the program will inquire if the participant has completed any required tasks or events. If the answer is “no” to that inquiry, the program proceeds via step progression 1004 a to inquiry 1018 . At inquiry step 1018 , the program inquires if the participant has used all of his or her allocated time to complete that particular Intermediate Stage, if there is a time limit assigned by the competition. If not and the participant still has an allocated time period to complete the Intermediate Stage, then the progress will proceed back to step progression 1003 and then inquiry 1004 , wherein the question regarding completion of tasks will be asked again. All websites and listing of standings will remain unchanged while a task has been uncompleted, and the to-be completed tasks can be designated as uncompleted by those words or another indicia (e.g. stop sign, red dot, etc.).
If the allocated time period 1018 is expired the step progression 1019 is taken to step 1020 . At that step 1020 , there is a decision made based on the rules specified for the sporting competition whether the participant is eliminated from the competition or given some point deduction (or other disadvantage) so that the participant can continue to participate in the competition.
If the rules dictate elimination of the participant, the program will proceed on progression step 1022 to the stop participation box 1023 . An information signal may be broadcast to the participant subject to elimination, as well as other participants that the fat that the subject participant is eliminated. Website listings and standings will be revised to show the eliminated status with some indicia like a “skull or cross bones” or “giant black X,” and the participant's vehicle may be required to fly a certain flag or show a light configuration that indicates elimination (e.g. pirate's flag, or four red lights, etc.).
If the rules dictate that the participant is not eliminated from the competition, the system may send a message to the participant notifying them to proceed to the next Intermediate Stage with a “green light” indicator message, but that progression to the next Intermediate Stage was not based on completion of tasks. Instead the computer-based system 11 will notify the participant to proceed to the next Intermediate Stage, but will deduct points or provide some other disadvantage to the participant because he or she did not complete the tasks in the allocated time. Website listings and standings will be revised to show the disadvantaged or penalty status of the participant with some type of negative indicia, and the participant may have to display a negative indicia on their vehicle (e.g. red flag, red light) to show their failure to complete a stage in the allocated time. After (or simultaneous therewith during step 1021 ) recording the penalty, the participant will proceed to the next Intermediate Stage where the computer-based system 11 will record his or her arrival at the next Intermediate Stage at step 1002 .
If at step 1004 , the program will record any event or task completion by progressing through step 1005 to the record step 1006 . The program operating at computer-based system 11 will be notified of task completion by the participant or observers, perhaps with photographic proof of completion. Once recorded, all websites standings and listings will be updated with an indicator that the specified task has been completed. The completion of the task may be broadcast to the other participants in the contest, and the participants participating in the contest will be notified that the task completion has been continued by the computer-based system 11 being a text message or some indicia message like a green light. The participant may also be allowed to show an indicia of task completion on his vehicle, such as fly a certain flag representative of the task or illustrating a certain light to represent task completion.
Once the task is recorded and notifications are transmitted, the progress operating on the computer-based system 11 will inquire at step 1008 whether all tasks required for the Intermediate Stage are completed. If not, the program will proceed on step progression 1016 to step progression 1004 a to test the time allocation. If all tasks have been completed, the program will proceed on step progression 1009 to an inquiry of whether the final stage has been completed. If not, the program progression will proceed on step progression 1011 to step 1002 where the participant will be given a “go” indicator to proceed to the next stage, and the system will record the participants' arrival at the next stage. If so, the program will proceed on step progression 1012 to step 1013 where the participant will be given a “go” indicator to proceed to the finish line and the system will record the participants' arrival time at the finish line.
As with the other steps in the program, the messages to the participants may be given by text message or other indicia regarding the proceed step. Also, the participant may be allowed to display an indicia of stage contest completion by flying flag or flags or illuminating certain lights on their vehicle. All website standings and listings will be updated to display event status of the participant, and the stage or contest completion may be broadcast to all participants or any interested spectators of the competition.
In FIG. 5 , the different activities conducted at each phase of the competition are shown. This flow chart at FIG. 5 starts at the Start Step 1050 , proceeds along the step progression to step 1052 , where the system will monitor the start at step 1053 , record video streams at step 1056 and receive information at the computer-based system 11 at step 1057 . Steps 1053 are coupled to the other steps and the stage step 1052 by connections 1060 , 1055 and 1054 , respectively. Step 1056 is coupled to the other steps and the stage step 1052 by connections 1060 , 1061 and 1059 , respectively. Step 1057 is coupled to other steps and the stage step 1052 by connections 1061 , 1055 and step 1058 , respectively.
Step 1052 will proceed to stage step 1071 via step progression 1070 , where the system will monitor the start at step 1053 , record video streams at step 1056 and receive information at the computer-based system 11 at step 1057 . Steps 1053 are coupled to the other steps and the stage step 1052 by connections 1060 , 1055 and 1054 , respectively. Step 1056 is coupled to the other steps and the stage step 1052 by connections 1060 , 1061 and 1059 , respectively. Step 1057 is coupled to other steps and the stage step 1052 by connections 1061 , 1055 and step 1058 , respectively.
Step 1052 will proceed to stage step 1071 via step progression 1070 , where the system will monitor the start at step 1053 , record video streams at step 1056 and receive information at the computer-based system 11 at step 1057 . Steps 1053 are coupled to the other steps and the stage step 1052 by connections 1060 , 1055 and 1054 , respectively. Step 1056 is coupled to the other steps and the stage step 1052 by connections 1060 , 1061 and 1059 , respectively. Step 1057 is coupled to other steps and the stage step 1052 by connections 1061 , 1055 and step 1058 , respectively.
Step 1052 will proceed to stage step 1071 via step progression 1070 , where the system will monitor the start at step 1053 , record video streams at step 1056 and receive information at the computer-based system 11 at step 1057 . Steps 1053 are coupled to the other steps and the stage step 1052 by connections 1060 , 1055 and 1054 , respectively. Step 1056 is coupled to the other steps and the stage step 1052 by connections 1060 , 1061 and 1059 , respectively. Step 1057 is coupled to other steps and the stage step 1052 by connections 1061 , 1055 and step 1058 , respectively.
As an overview, the systems and methods support and conduct the proposed contest from a starting position a Starting Point. The starting point may be at the same location, at the same exact time, or staggered in some fashion (e.g., (i) at different locations, at the same time; (ii) at the same location, at different times; (iii) at different locations, at different times). Each contestant (or team of contestants) are expected to catch at least one fish of one or more varieties or sizes of fish. Alternatively, in the case of a team of contestants, each member of the team may be required to catch a fish from a designated species or from a group of multiple designated species.
All contestants are expected, then, to record their catch(es) as qualifying catch(es), before moving from the first stage area to the second stage area. In each succeeding stage area, the contestant may be required to record their qualifying catch(es) in that stage area before moving to the next stage area in the contest course. Once they have recorded qualifying catches in all of the stage areas, the contestant, or team, may then proceed to the finishing point. The first contestant to reach the finishing point with qualifying catches in all stage areas, wins the contest places for the contestants, who finish the contest with qualifying catches in all stage areas, will be based on the order in which they arrive at the finishing point after completing their qualifying catches in all of the stage areas.
The invention as described herein is intended to operate in a variety of geographic settings and configurations as to the type of fishing (freshwater river, freshwater lake, saltwater bay, saltwater offshore), or Hunting (game, bird), the mode of transportation allowed (e.g., powered watercraft, unpowered watercraft, bicycle, motorcycle, automobile, foot) and the species or groups of species of fish (or other animal) targeted in the contest. Some key components or features include the elements of time, with or without breaks, as in a race, as well as endurance, over a pre-defined distance or pre-defined amount of time.
The invention is designed to offer variations in the configurations of particular contests. For example, a fishing contest could require contestants to complete a predefined course along either a saltwater coastline, or a freshwater river, or a series of unconnected lakes within a predetermined period of time. In each of the fishing variations, contestants could be required to catch specific species or combinations of specific species of fish either during their completion of the entire defined course, or before progressing from one predetermined section of the course to the next section of the course.
A hunting version of the invention could require contestants to complete a predefined course laid out over a geographic area comprising a single mass of land, or a course over several non-contiguous geographic areas, within a predetermined period of time. In each of the hunting variations, contestants could be required to shoot or photograph specific species of game or birds during their completion of the course, or before progressing from one predetermined section of the course to the next section, or before moving from one non-contiguous geographic area to the next.
FIG. 6 is a flow chart showing the basic structure, method and system design of a preferred contest. In this illustration, a time line 100 is shown, starting with contest start 101 and ending with contest finish 123 . Along time line 100 , there are Seven (7) stage areas, each of which are denoted by a triangle pointed downward at locations 103 , 106 , 109 , 112 , 115 , 118 , and 1212 . Of course, in alternate embodiments, the number of stage areas, along with the locations, may vary. Stage areas generally refer to the location that the specific event must occur. For instance, a contestant may be expected to catch a small mouth bass in the certain location of a river. Additional requirements may be added as well.
For instance, the small mouth bass must be caught with an artificial lure, in shallow water, from a boat. Or, the contestant may be required to catch a combination of fish, for instance a smallmouth bass, a largemouth bass, and a walleye in each stage area before moving to the next. Or, the contestant may be required to catch one smallmouth bass with an artificial lure and one small mouth bass with live bait before moving from one stage area to the next stage area. Other variations could require the contestants to begin the contest with NO BAIT, requiring them to catch their own minnows, shad or other live bait while completing the overall contest course.
Referring again to FIG. 6 , upon starting the contest, at contest start 101 , contestant(s) enter first stage area (stage area 1), at 102 . Of course, the contest start, at 101 , may physically start at first stage area (stage area 1). Contestant(s) are then expected to catch the required species of fish, at 103 , and record the catch(es), at 104 , in first stage area (stage area 1) before moving to the next stage area, namely second stage area (stage area 2).
After having completed the fishing and recording requirements of the previous stage area, namely first stage area (stage area 1), contestant(s) are able to enter second stage area (stage area 2), at 105 . There, at second stage area (stage area 2), contestant(s) must catch the required species of fish, at 106 , and record the catch(es), at 107 , in second stage area (stage area 2) before moving to the next stage area, namely third stage area (stage area 3).
After having completed the fishing and recording requirements of the previous stage area, namely second stage area (stage area 2), contestant(s) are able to enter third stage area (stage area 3), at 108 . There, contestant(s) are expected to catch the required species of fish, at 109 , and record the catch(es), at 110 , in third stage area (stage area 3) before moving to the next stage area, fourth stage area (stage area 4).
After having completed the fishing and recording requirements of the previous stage area, namely third stage area (stage area 3), contestants are able to enter fourth stage area (stage area 4), at 111 . There, contestant(s) are expected to catch the required species of fish, at 112 , and record the catch(es), at 113 , in fourth stage area (stage area 4), before moving to the next stage area, namely fifth stage area (stage area 5).
After having completed the fishing and recording requirements of the previous stage area, the contestants are able to enter fifth stage area (stage area 5), at 114 . There contestant(s) are expected to catch the required species of fish, at 115 , and record the catch(es), at 116 , at fifth stage area (stage area 5) before moving to the next stage area, namely sixth stage area (stage area 6).
After having completed the fishing and recording requirements of the previous stage area, the contestant(s) are able to enter sixth stage area (stage area 6), at 117 . There, contestant(s) are expected to catch the required species of fish, at 118 , and record the catch(es), at 119 , in sixth stage area (stage area 6) before moving to the next stage area, namely seventh stage area (stage area 7).
After having completed the fishing and recording requirements of the previous stage area, namely sixth stage area (stage area 6), contestant(s)s are able to enter seventh stage area (stage area 7), at 120 , which in the illustration shown in FIG. 1 is the final stage area. There, contestant(s) are expected catch the required species of fish, at 121 , and record the catch(es), at 122 , in seventh stage area (stage area 7), before finishing the contest, at 123 .
FIG. 7 is a flow chart that shows a detailed timeline of a possible contest, with four contestants or teams of contestants competing with one another. While the geographic location of the disclosed competition may change, FIG. 8 depicts a high level map of the Texas coastline on the Gulf of Mexico, indicating the Starting Point, each of seven exemplary stage areas, each of seven (7) stage area recording stations, if the example contest used recording stations to record qualifying catches, and the finishing point of the contest.
Potential paths of contestants are shown along path 304 , from Sabine Pass in the East to Port Isabel in the Southwest. As shown in FIG. 8 , the Texas coastline is broken into a number of stage areas, the precise boundaries of which, of course, can be modified. Again, for the exemplary purposes only, the first stage area 302 (Sabine Pass), second stage area 305 (Galveston), third stage area 307 (Matagorda), fourth stage area 309 (San Antonio Bay), fifth stage area 311 (Aransas), sixth stage area 213 (Upper Laguna), and seven stage area 315 (Lower Laguna). Path 304 starts at contest starting point 301 and concludes at finish point 316 . Circles 303 , 306 , 308 , 310 , 312 , 314 , and 316 designate, within each of the stage areas 302 , 305 , 307 , 309 , 311 , 313 , and 315 , stage area recording stations or qualifying stations for stage areas 302 , 305 , 307 , 309 , 311 , 313 , and 315 , respectively.
In particular, to be more specific geographically as a way to further understand the disclosed contest and related systems and methods, referring to FIG. 7 , contest starting point 301 is in the Sabine area on the border between Texas and Louisiana (northeast edge of the Texas Gulf Coast). First stage area 302 , referred to as “Sabine Pass and Lake” in FIG. 6 , includes Sabine Lake and Sabine Pass. First recording station 303 at first stage area 302 (in FIG. 8 ) is located in a marina or waterfront facility at Sabine Pass. Competing contestants of fishermen will move between stage areas via the IntraCoastal Canal or path 304 . Second stage area 305 , referred to as “Galveston Bay Complex” in FIG. 7 , includes East Galveston Bay, Trinity Bay, Galveston Bay, West Galveston Bay, and Christmas Bay. Recording station 306 for second stage area 305 is located at San Luis Pass, between West Galveston Bay and Christmas Bay.
Third stage area 307 , referred to as “East and West Matagorda Bays” in FIG. 7 , includes East Matagorda Bay, West Matagorda Bay, and Lavaca Bay. Third Recording station 308 for third staging area 307 is located on the water in Port O'Connor, Tex. Fourth stage Area 309 , referred to as “San Antonio Bay” FIG. 7 , includes Espiritu Santo Bay, San Antonio Bay, and Mesquite Bay. Fourth recording station 310 for stage area 309 is located on the water at Seadrift, Tex. Fifth stage area 311 , referred to as “Aransas Bay-Copano Bay-Redfish Bay” in FIG. 7 , includes Aransas Bay, Copano Bay, Redfish Bay, and Corpus Christi Bay.
Fifth recording station 312 for fifth stage area 311 is located at the JFK Causeway between Corpus Christi Bay and Upper Laguna Madre. Sixth stage area 313 , referred to as “Upper Laguna Madre,” includes the Upper Laguna Madre, Baffin Bay, and Alazan Bay. The sixth recording station 314 for stage area 313 is located on the water on the Upper Laguna Madre. And, the seventh stage area 315 , referred to as “Lower Laguna Madre” includes the Upper Laguna Madre, and Arroyo Colo. The seventh recording station 316 for Seventh stage area 315 is located on the water in Port Isabel, Tex.
To further understand a disclosed contest, an example of such a contest is shown in FIG. 7 . Referring to FIG. 7 , timeline 200 , is shown in hours, extending from left to right. Teams of contestants 1-4 are represented by various geometric shapes 202 , 242 , 247 , and 249 . Each team 202 , 242 , 247 , and 249 enter stage area 1, at time 203 . Referring to FIG. 8 , stage area 1 (in FIG. 7 ) corresponds to first stage area 302 , which is the Sabine Pass or “Sabine Pass and Lake,” as shown in FIG. 7 . As a point of information, the Sabine Pass is the coastal line between the States of Texas and Louisiana. Similarly, the finish line is Port Isabel, near stage area 7, which is labeled “Lower Laguna Madre” in FIG. 7 , is near the border between State of Texas and Mexico.
In the example shown in FIG. 7 , teams 202 , 242 , 247 , and 249 reach the finish line, at different times, 241 , 246 , 251 , and 254 , respectively. In order to complete this course, contestants might be required to catch fish in each of seven major bay areas that lie between the start and end points. For example, as depicted in FIG. 8 and discussed above, the Texas coastline with the Gulf of Mexico, between the State of Louisiana and Mexico can be divided up into seven staging areas: (i) Sabine Pass and Lake; first stage area 302 ; (ii) Galveston Bay Complex; second stage area 305 ; (iii) East and West Matagorda Bays, third stage area 307 ; (iv) San Antonio Bay, fourth stage area 309 ; (v) Aransas Bay-Copano Bay-Redfish Bay, fifth stage area 311 ; (vi) Upper Laguna Madre, sixth stage area 313 ; and (vii) Lower Laguna Madre, seventh stage 315 .
As devised and shown in FIGS. 7 and 8 , a team of contestants may be required to catch one fish from a set group of fish species from each of these seven designated areas or stage areas. And, once a team of contestants has recorded the required catch in the first area, the team may proceed to the second area. When the team of contestants records the required catch in the second stage area, the team of contestants may proceed to the third, and so on. The designated species required to be caught along the way could also include a requirement that the team of contestants must catch at least one fish from each of the designated species, before completing the contest.
For example, in the above Texas coastline example shown in FIGS. 7 and 8 , competing teams could be required to catch fish from the three primary in-shore gamefish species from this area, such as Southern Flounder (flounder), Red Drum (redfish), and Spotted Seatrout (speckled trout). Next, a team could move forward from the first area by catching, for example, a flounder in first stage area. Thereafter, a team may be expected to catch a redfish in second stage area, after which a team could move on to third stage area and so on. If, by the time a team reaches the final stage area, namely seventh stage area, and, if a team had caught fish from just two of the three required species, a team would have to catch the remaining species before they could finish. In other words, if by the time the team reached Port Isabel, the last stage area, seventh stage area, if the team had caught redfish and trout, but no flounder, the only species they could catch in the last area to qualify to finish would be a flounder.
In this specific example of a contest shown in FIG. 7 , the proposed contest has a timeline 200 estimated to require forty-eight (48) hours for competing first to fourth teams 202 , 242 , 247 , and 249 , to finish. Though the rules may be modified, the general rule assumptions for this hypothetical contest are shown in box 203 are as shown: In particular, teams consist of two Fishermen. Transportation between stage areas is by motorized boat, no trailering is allowed. There are seven stage areas. Each team must catch one of three species in each stage area. Each team must catch at least one of the three species before finishing. Each team member must catch at least one of the three before finishing at certain stage. A team records only one species per stage area. Designated fish species are as follows: Southern Flounder (flounder), Red Drum (redfish), and Spotted Seatrout (trout).
In addition, qualifying species flags 255 (or some other indicia indicating the requirement has been met) are given to teams and team members when they record the first fish caught in each required species. To qualify to finish in the example contest described in FIG. 7 , each team must record one redfish, one trout, and one flounder in any of the seven stage areas and receive a species qualifying flags for each species. Each team member must also qualify to finish by recording one redfish, one trout, and one flounder in any of the seven stage areas and receive an individual qualifying flag for each species.
Exemplary Results of First Team 202
In the example of a potential contest, the results of which are shown in FIG. 7 , first team 202 enters first stage area 302 (in FIG. 8 ), at 203 , in the first hour of the contest. In first stage area 302 (in FIG. 8 ), team member 1 B catches a flounder, at 204 , in the first hour; first team member 1 A catches a flounder within the second hour, at 205 . First team 202 records the flounder as its team qualifying catch for first stage area 302 , at time 206 . Some sort of acknowledgement, such as qualifying flags 207 , are given to first team 202 , for first team member 1 A, for flounder, and, for second team member 1 B, for Redfish, at some sort of a qualifying station for first stage area 302 .
First team 202 , then, enters second stage area 305 (in FIG. 8 ), at time 208 , in the sixth hour. First team member 1 A catches a redfish in the seventh hour, at time 209 . First team member 1 B catches nothing in second stage area 305 (in FIG. 8 ), at time 210 . Therefore, first team 202 records a Redfish as its qualifying catch for second stage area, at time 211 and is awarded an individual qualifying flag for flounder/redfish. First team 202 now has team flags for flounder and redfish. First team member 1 A has individual qualifying flags for flounder and redfish, and first team member 1 B has a qualifying flag for redfish, at time 212 .
Thereafter, first team 202 enters stage area 307 (in FIG. 8 ), after 11½ hours, at time 213 . First team member 1 A catches a redfish in the thirteenth hour, at time 214 . First team member IB catches a redfish in the fifteenth hour, at time 215 . First team 202 records redfish as its qualifying catch in third stage area 307 (in FIG. 8 ), at time 216 . As a result, first team 202 , first team member 1 A, and first team member 1 B qualifying flag counts are unchanged in third stage area 307 (in FIG. 8 ), at time 217 .
First team 202 enters stage area 309 , after 18 hours, at time 218 . First team member 1 A catches a redfish in the twenty-first hour, at time 219 . Team member IB catches a trout in the twenty-third hour, at time 220 . First team 202 records the trout as their qualifying catch for fourth stage area 309 (in FIG. 8 ), at time 221 . First team 202 receives a qualifying flag for trout, first team member 1 B receives a qualifying flag for trout, first team member 1 A's qualifying flag count remains unchanged, at time 223 .
First team 202 enters fifth stage area 311 (in FIG. 8 ), after 25 hours, at time 224 . Team member IB catches a redfish in the twenty-seventh hour, at time 225 . Team member 1 A catches a trout in the thirty-first hour, at time 226 . First team 202 records the trout as its qualifying catch for fifth stage area 311 (in FIG. 8 ), at time 227 . Team member 1 A now has all 3 qualifying species, at 228 . Team member IB's qualifying flag count remains unchanged, at 229 .
First team 202 enters sixth stage area 313 (in FIG. 8 ), after 33 hours, at 230 . Team member IA catches a trout in the 34th hour, at time 231 . Team member 1 B catches nothing in sixth stage area 313 (in FIG. 8 ), at time 232 . First team 202 records the trout as their qualifying catch for sixth stage area 313 , at time 233 . First team 202 's qualifying flag counts remain unchanged, at 323 .
First team 202 enters seventh stage area 315 (in FIG. 8 ), which is the final area, after 39 hours, at 235 . Team member 1 A catches a trout in the forty-first hour, at time 236 . Team member 1 B catches a Flounder in the 44th hour [ 237 ]. Team member 1 B now has all 3 qualifying species, at 238 . First team 202 record's team member 1 B's flounder at the finishing point recording station, at time 239 . First team 202 , team member 1 A, team member 1 B now has all required qualifying flags, at 240 . First team 202 finishes the contest in 45 hours, at time 241 .
Exemplary Results of Second Team 242
Second team 242 enters first stage area 302 (in FIG. 8 ) at the same time first team 202 does. Second team 242 has similar experiences in first stage area 302 through seventh stage area 315 (in FIG. 8 ) as First team 202 . Second team 242 records qualifying catches of all three (3) required species for the second team by third stage area 3, at time 243 . Second Team member 2 A records qualifying catches of all three (3) required species by fifth stage area 311 (in FIG. 8 ), at time 244 , and team member 2 B records qualifying catches of all three (3) required species by sixth stage area 313 , at time 245 . Second team 242 finishes the contest in 47 hours, at time 246 .
Exemplary Results of Third Team 247
Third team 247 enters first stage area 302 (in FIG. 8 ) at the same time as first team 202 and second team 242 . Third team 247 also has similar experiences to those of first team 202 and second team 242 . Species qualifying catch requirements are met by Third team 247 , at time 248 and third team member 3 B, at time 249 , by fourth stage area 309 . Team member 3 A finally meets three qualifying species catches requirement, at time 250 , while fishing in seventh stage area 315 . Third team 247 finishes in 44 hours, at time 251 .
Exemplary Results of Second Team 249
Fourth team 249 enters first stage area 302 (in FIG. 8 ) at the same time as first team 202 , second team 242 , and third team 247 . Fourth team 249 falls behind the other teams and does not enter the Seventh stage area 315 , until the 46th hour, at time 253 . Fourth team 249 finishes well after the 48th hour, at time 252 .
Scoring Options
A variation of the rules would allow contestants to fish in teams, in which each team of 2, 3, or more fishermen would compete against other teams. This variation could either be structured so that each contestant team must catch one of the designated species before moving from one area to the next (anyone of the members could catch the one fish needed); or, every member of the contestant team could be required to catch one the designated species before moving to the next area (2 team members, 2 fish out of the designated species must be caught). Alternatively, if just one fish per team is required, the rules could require that each member must record catching at least one fish of each designated species somewhere along the course before finishing. In the example shown in FIG. 7 and discussed above, if there are two members and the team has caught a flounder in first stage area 302 (in FIG. 8 ), a trout in stage area 305 (in FIG. 8 ), a redfish in third stage areas 307 (in FIG. 8 ), fourth stage area 309 (in FIG. 8 ), and fifth stage area 311 (in FIG. 8 ), a trout in sixth stage area 313 (in FIG. 8 ), but team member A has not recorded a flounder, the team's required catch for seventh stage area 316 (in FIG. 8 ) would be a flounder, caught by team member A.
Alternate Ways of Recording the Event (“the Catch”)
There is a multitude of ways that one can record a catch. For instance, fish caught can be released, consistent with “Catch and Release” policies, once the catch has been documented (e.g., photographed, witnessed, measured, weighed, etc.). The photograph is then submitted to contest officials, who use the photographed measurement to determine the relative size of the recorded catches, and then rank the submitted catches from all competing fishermen.
Alternatively, competing fishermen to bring the fish they have caught to a central recording station, where the fish are weighed or otherwise measured and recorded. To record a fish in these circumstances, the fisherman must present the fish alive. It is then released by officials of the fishing contest, or in some cases under the supervision of wildlife biologists or representative of local, state, or even federal game and fish authorities.
As another modification, in non-catch and release version of the preferred embodiments of the fishing contests, the competing fishermen are required to bring the fish they have caught during the contest to a central location where the fish are measured and weighed. In this version, no attention is paid to the condition of the fish (e.g., alive or dead), as long as they meet legal requirements for presiding fish and wildlife authority in whose jurisdiction the contest is conducted. Competing fishermen either keep their fish after having them recorded, or turn them into the contest officials, who in turn either donate them to relief kitchens, cook and serve them to contest participants, or simply dispose of them.
There are further modifications or alternative formulations of the preferred embodiment. One such alternative is to establish multiple recording stations along the contest route. These recording stations would be manned throughout the contest, or until the last of the registered competing fishermen or teams had recorded their required catch for that recording station's area. In the Texas Coast example above, recording stations are preferably established at easily accessible locations (ideally in Marinas or other similar water-side facilities) in the Sabine Pass area, in the Galveston area, in the Matagorda area, on San Antonio Bay, in the Aransas Bay area, in the Upper Laguna Madre area and at the finish position in the Port Isabel area.
These recoding stations at these locations would record the weight and species of each fish submitted and then would take possession of the fish and insure that the fish were released alive. The fish would have to be alive and in survivable condition in order to be submitted and therefore recorded for qualification to move on to the next stage area. Upon having a catch recorded at a stage area's recording station, the contestant would be issued a certified flag marker for that stage area or given some other indicia of having completed the stage. A flag has the advantage of being a visible reminder to the contestant as well as communicate the success or status of the completion of each task to the other contestants. For instance, each stage area could have a different color flag mark and/or a different shape or have other indicia showing the relative place, etc. Once the flag marker was issued, the contestant, or team, would be able to proceed to the next stage area on the contest route.
An additional alternative is to employ a number of “chase vessels” to follow the competing fishermen. The “chase vessels” may be equipped with video cameras for the purpose of recording the fishing action of various competing fishermen, or teams. Each contestant, or team, would be issues a GPS tracking device so that their exact location could be recorded at all times. Each contestant, or team, would also be required to have a radio and cell phone with them, and to use these communication devices to report each catch they wish to record.
Once a catch is reported, one of the chase vessels would proceed to the GPS coordinates of the reporting fisherman, or team. When the chase vessel reaches the location of the reporting fisherman, a contest official on the chase vessel would weigh, and or measure the catch, verify that it is in a survival condition, record the catch photographically and/or video graphically, and supervise the release of the recorded fish. The contest official would then issue the contestant, or team, a certified flag marker for the stage area where the catch was recorded. With this certified flag marker, the Contestant, or team, would then proceed to the next stage area on the contest Route.
In the example of the Texas Coast contest discussed above in reference to FIGS. 7 and 8 , competing fishermen, or teams, would have to possess all seven certified flag markers to finish in contention for the contest.
Scoring Methods
The outcome of the contest could be determined in two types of scoring methods.
One scoring method, referred to as a first scoring method, would simply rank the finishing contestants or teams of contestants in the order in which they successfully completed the contest, with the first to finish determined as the winner, the second to finish as second place and so on.
A second scoring method, referred to as a second scoring method, would increase the strategic complexity of the contest by using a scoring system in which points were awarded to the contestants or teams of contestants completing the contest, with several different embodiments: As a modification to this scoring method, the scoring system would award points on a sliding scale: The contestant or team of contestants who finished the contest first would get 40 points out of 100; the contestant or team of contestants who finished the contest second would get 15 points out of 100; and the contestant or team of contestants who finished the contest third would get 5 points out of 100. The remaining 40 points would be divided and awarded to the teams based on the si and/or number of fish caught.
If the contest were to designate 3 species the contestant or team of contestants who caught the largest of each species would get 10 points and the contestant or team of contestants who caught the largest number of fish would get 10 points. In this way, the contestant or team of contestants who did not finish the contest first could still accumulate the largest number of points overall and prevail in the contest. For example, if first team 202 finishes first and is awarded 40 points, and Second team 242 finishes second and is awarded 15 points, and third team 247 finishes third and is awarded 5 points, and second team 242 also has the largest fish in both Species A and Species B, and has caught the largest number of fish overall, Second team 242 will receive an additional 30 points for a total of 45 points.
If Third team 247 has the largest fish in Species C, then First team 202 , who finished first, does not receive any additional points. The Scoring results would then show: First team 202 , 40 points; Team 2 , 45 points, Third team 247 , 10 points. Second team 242 would be the overall winner. The strategic complexity of this scoring method would reward contestants or teams of contestants who were able to more successfully apply their fishing skills (and luck) while also successfully completing the contest course in at least the top three positions. In this case, a contestant or team of contestants who found the opportunity to record more or larger fish might make the strategic decision to slow their pace in order to capitalize on the catch opportunities. The modification would require that more than one fish per contestant, or per member of a team of contestants, could be recorded in each stage area, with the largest of the selected species of fish being used as the Qualifying Catch.
A potential modification to this second scoring method could be used where a contest designated only one species of fish, the system would still award a sliding scale of points to the order of contestants or teams of contestants who finish in the first three positions. But, the system would then award the remaining points to the largest single fish and the largest number of fish recorded by all finishers.
For example, first to finish would get 40 points out of 100; second would get 15 points out of 100; third would get 5 points out of 100. Then, the contestant or team of contestants who caught the largest overall fish would get 30 points; and the largest overall number of fish would get 10 points. If first team 202 finishes first and gets 40 points, but Second team 242 finishes second and also catches the largest fish, and third team 247 finishes third for 5 points, and has the largest number of fish, the scoring results would be: First team 202 , 40 points; team 2 , 45 points; third team 247 , 15 points. Second team 242 wins. If first team 202 finished third with the most fish, but also had the largest single fish, the result would be: First team 202 , 40 points; team 2 , 15 points; third team 247 , 45 points. Third team 247 wins.
These modifications have the advantage of making it possible for contestants, or teams of contestants, who do not finish in the top three positions, to be awarded at least as many points as the first to finish (however, in the case of a tie between the first finisher and another contestant, the first finisher would be declared contest winner).
FIG. 9 is a map providing an example of a course from start to finish on The Mississippi River, indicating the Starting Point, each of 15 Example stage areas, each of 15 stage area recording stations, if the example contest used recording stations to record Qualifying Catches, and the Finishing Point of the contest. In this example, the contest starting point 401 is in the Minneapolis-St. Paul, Minn. area.
First stage area 402 is in the Minneapolis-St. Paul area and runs from the starting point 401 in the Minneapolis-St. Paul area to a recording station 403 at Bay City, Wis., which is approximately 100 miles downriver from the starting point 401 .
Second stage area 404 is in the La Crosse area and runs from the recording station 403 to a recording station 405 at La Crosse, Wis., which is approximately 1500 miles downriver from the first stage area 402 .
Third stage area 406 , Dubuque, runs from the recording station 405 to a recording station 407 at Dubuque, Iowa [ 407 ], approximately 180 miles downriver from second stage area 404 .
Fourth stage area 408 , Quad Cities, runs from just below Dubuque, Iowa to the recording station 409 for fourth stage area at Rock Island, Ill., approximately 150 miles downriver from third stage area.
Fifth stage area 410 , Fort Madison, runs from just below Rock Island, Ill. to the recording station 411 for fifth stage area 410 at Fort Madison, Iowa, approximately 150 miles downriver from fourth stage area.
Sixth stage area 412 , Hannibal, runs from just below Fort Madison, Iowa to the recording station 413 , at Hannibal, Mo., approximately 140 miles downriver from fifth stage area 410 .
Seventh stage area 414 , St, Louis, runs from just below Hannibal Mo. to the recording station 415 for seventh stage area 414 , at St. Louis, Mo., approximately 180 miles from sixth stage area 412 .
Eighth stage area 416 , Cape Girardeau, runs from just below St, Louis to the recording station 417 for eighth stage area 416 at Cape Girardeau, Mo., approximately 170 miles downriver from seventh stage area 414 .
Ninth stage area 418 , Caruthersville, runs from just below Cape Girardeau, Mo. to the recording station 419 for ninth stage area 418 at Caruthersville, Mo., approximately 150 miles downriver from eight stage area 416 .
Tenth stage area 420 , Memphis, runs from just below Caruthersville, Mo. to the recording station 421 for tenth stage area 420 at Memphis Tenn., approximately 130 miles downriver from ninth stage area 418 .
Eleventh stage area 422 , Rosedale, runs from just below Memphis, Tenn. to the recording station 423 for eleventh stage area 422 at Rosedale, Miss., approximately 180 miles downriver from tenth stage area.
Twelfth stage area 424 , Vicksburg, runs from just below Rosedale, Miss. to the recording station 425 for twelfth stage area at Vicksburg, Miss., approximately 180 miles downriver from eleventh stage area 422 .
Thirteenth stage area 426 , Natchez, runs from just below Vicksburg, Miss. to the recording station 427 for thirteenth stage area at Natchez, Miss., approximately 100 miles downriver from twelfth stage area 424 .
Fourteenth stage area 428 , Baton Rouge, runs from just below Natchez, Miss. to the recording station 429 for stage area 14 at Baton Rouge, La., approximately 120 miles downriver from thirteenth stage area 426 .
Fifteenth stage area 430 , New Orleans, the Finish Line stage area, runs from just below Baton Rouge, La. to the recording station 431 for fifteenth stage area 430 at the Finishing Point 431 in New Orleans, La., approximately 150 miles downriver from fourteenth stage area 14 .
Additional Embodiments
Another variation on this invention is the possibility of applying it in other fields of outdoor sporting competition. One example would be a similar contest in the field of hunting. For example, a contest covering a predetermined geographic course, similar to those geographic courses used in the fishing competition examples, could involve hunting for a variety of species, including dove, turkey, ducks, geese, feral hogs, predators, deer, sheep, elk. Just as with the fishing example, the hunting version could involve multiple species in a single contest. It could also involve a limited time period in which contestants were required to complete the geographic course.
An example contest could be one in which contestant hunters would be required to hunt ducks along the entire Texas Coastline and to shoot one of a group of subspecies of duck, for example, Gadwall, Widgeon, Mallard, and Pintail in each stage area before moving to the next stage area. As with the fishing example, they could also be required to shoot at least one of each species before completing the contest. Note it is also possible to string together hunting seasons, such as a hunter would be expected to hunt ducks in a duck season, in Texas, and a deer, in deer season, in Colorado. While the invention has been particularly shown and described with respect to preferred embodiments, it will be readily understood that minor changes in the details of the invention may be made without departing from the spirit of the invention. | The present invention conducts, monitors, and regulates the sporting-event that takes place over an extended geographic area, during an extended time period, with intermediate event-based stages occurring before arriving at the finish line. The sporting competition will require the participants to demonstrate a multitude of skills with each participant having to complete a task or tasks at each intermediate stage in the competition prior to proceeding to the next stage, and ultimately, to finish the race. To finish, a contestant, or team of contestants, must have accomplished a task or set of tasks at each intermediate stage for each of the designated segments along the course route of the contest. In that way, the present invention will conduct an endurance race that is more akin to marathon foot race with intermediate event-based stages, as opposed to a modern fishing competition. | 6 |
FIELD
[0001] The present disclosure relates generally to a lock assembly and more particularly to a lock assembly for a vehicle having a tailgate or other removable closure.
BACKGROUND
[0002] This section provides background information related to the present disclosure and is not necessarily prior art.
[0003] Many motor vehicles come equipped with tailgate assemblies. For example, pickup trucks often include a tailgate assembly that controls access to a bed portion of the pickup truck. In some implementations, tailgate assemblies are removably supported by the bed portion of the pickup truck. In this regard, the full functionality of the truck bed can be utilized by opening the tailgate assembly and/or removing the tailgate assembly from the pickup truck. The removability of tailgate assemblies can also make them vulnerable to car thieves. For this reason, locking systems have been developed to prevent inadvertent and other unwanted removal of the tailgate assembly from the vehicle. In this regard, some vehicles may utilize a handle locking system that prevents the tailgate assembly from opening and, thus, prevents the tailgate assembly from being removed from the vehicle. Other vehicles may utilize a projection locking system that prevents the tailgate assembly from being removed, regardless of whether the tailgate is open or closed.
[0004] Current handle locking systems are susceptible to being easily overridden and, as such, allow unauthorized individuals to remove the tailgate assembly from the vehicle. Current projection locking systems provide an added degree of security as compared to handle locking systems but do not allow authorized users to easily remove the tailgate assembly.
SUMMARY
[0005] This section provides a general summary of the disclosure, and is not a comprehensive disclosure of its full scope or all of its features
[0006] A system for securing a tailgate to a vehicle body is provided and includes a housing secured to one of the tailgate and the vehicle body, the housing including a passageway. A projection is secured to the other of the tailgate and the vehicle body and is rotatably received by the housing in an attached state to rotatably attach the tailgate to the vehicle body and is separated from the housing in a detached state to permit removal of the tailgate from the vehicle body. The system also includes a locking mechanism operable in a locked state to block the passageway and prevent movement of the projection from the attached state to the detached state and an unlocked state opening the passageway to permit movement of the projection from the attached state to the detached state.
[0007] In some configurations, the system includes a controller in communication with the locking mechanism. The controller may move the locking mechanism between the locked state and the unlocked state. A driver may be in communication with the controller and may move the locking mechanism between the locked state and the unlocked state. The driver may be a solenoid or a reversing motor.
[0008] An authorization system may authenticate a valid user. The controller may prevent movement of the locking mechanism from the locked state to the unlocked state until the authorization system identifies a valid user. The authorization system may identify a valid user based on input from at least one of a key fob, a phone, or a switch.
[0009] In some implementations, the system includes an actuation member operable to transmit a wake-up signal to the authorization system. The controller may be operable in a dormant state until the actuation member transmits the wake-up signal to the authorization system. In some implementations, the controller may be operable to transition to a dormant state after a predetermined amount of time. The predetermined amount of time may be between 20 seconds and 120 seconds after transmission of the wake-up signal. In some implementations, the predetermined amount of time is measured by one of a timer and a capacitive charging device.
[0010] In some configurations, the locking mechanism includes a lock member blocking the passageway when the locking mechanism is in the locked state and spaced apart from at least a portion of the opening when the locking mechanism is in the unlocked state. The lock member may be slidably supported by the housing for movement along an arcuate path between the unlocked state and the locked state.
[0011] The projection may be rotatable about an axis when in the attached state to permit rotation of the tailgate relative to the vehicle body. The lock member may be rotatable about the axis between the locked state and the unlocked state.
[0012] According to another aspect, a method for securing a tailgate to a vehicle body is provided. The method may include securing a housing having a passageway to one of the tailgate and the vehicle body. The method may also include securing a projection to the other of the tailgate and the vehicle body. The projection may be rotatably received by the housing in an attached state to rotatably attach the tailgate to the vehicle body and may be separated from the housing in a detached state to permit removal of the tailgate from the vehicle body. The method may further include positioning a locking mechanism in one of a locked state blocking the passageway and preventing movement of the projection from the attached state to the detached state and an unlocked state opening the passageway and permitting movement of the projection from the attached state to the detached state.
[0013] In some implementations, the method includes providing a controller in communication with the locking mechanism. The controller may move the locking mechanism between the locked state and the unlocked state.
[0014] In some implementations, the method includes providing a driver in communication with the controller. The driver may move the locking mechanism between the locked state and the unlocked state. In some implementations, providing the driver may include providing a solenoid or a reversing motor.
[0015] In some implementations, activation of the controller may occur through communication (e.g., wired or wireless) between the locking device and an onboard transmitting device. For example, the activation of the controller may occur by activating the locking device after vehicle authentication protocols identify a valid user.
[0016] The method may additionally include providing an authorization system operable to authenticate a valid user. The method may include preventing movement of the locking mechanism from the locked state to the unlocked state via the controller until the authorization method identifies a valid user. In some implementations, identifying a valid user by the authorization system is based on input from at least one of a key fob, a phone, or a switch.
[0017] In some implementations, positioning the locking mechanism in the locked state includes blocking the passageway with a lock member. Positioning the locking mechanism in the unlocked state may include spacing the lock member from at least a portion of the opening.
[0018] In some implementations, the method includes slidably supporting the lock member by the housing for movement along an arcuate path between the unlocked state and the locked state. The method may include permitting rotation of the projection about an axis when in the attached state to permit rotation of the tailgate relative to the vehicle body. The lock member may be rotatable about the axis between the locked state and the unlocked state.
[0019] Further areas of applicability will become apparent from the description provided herein. The description and specific examples in this summary are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure.
DRAWINGS
[0020] The drawings described herein are for illustrative purposes only of selected configurations and not all possible implementations, and are not intended to limit the scope of the present disclosure.
[0021] FIG. 1A is a perspective view of a vehicle having a tailgate and a tailgate lock assembly in accordance with the principles of the present disclosure, the tailgate shown in a latched state;
[0022] FIG. 1B is a perspective view of the vehicle of FIG. 1A , the vehicle shown in an unlatched state;
[0023] FIG. 2 is an exploded view of the tailgate lock assembly of FIG. 1A , including a projection in accordance with the principles of the present disclosure;
[0024] FIG. 3A is a cross-sectional view of the tailgate lock assembly of FIG. 1A in a locked position;
[0025] FIG. 3B is a cross-sectional view of the tailgate lock assembly of FIG. 1A in an unlocked position;
[0026] FIG. 4A is a perspective view of a tailgate coupled to a vehicle using a tailgate lock assembly in accordance with the principles of the present disclosure; and
[0027] FIG. 4B is a perspective view of a tailgate removed from a vehicle using a tailgate lock assembly in accordance with the principles of the present disclosure.
[0028] Corresponding reference numerals indicate corresponding parts throughout the drawings.
DETAILED DESCRIPTION
[0029] Example configurations will now be described more fully with reference to the accompanying drawings. Example configurations are provided so that this disclosure will be thorough, and will fully convey the scope of the disclosure to those of ordinary skill in the art. Specific details are set forth such as examples of specific components, devices, and methods, to provide a thorough understanding of configurations of the present disclosure. It will be apparent to those of ordinary skill in the art that specific details need not be employed, that example configurations may be embodied in many different forms, and that the specific details and the example configurations should not be construed to limit the scope of the disclosure.
[0030] The terminology used herein is for the purpose of describing particular exemplary configurations only and is not intended to be limiting. As used herein, the singular articles “a,” “an,” and “the” may be intended to include the plural forms as well, unless the context clearly indicates otherwise. The terms “comprises,” “comprising,” “including,” and “having,” are inclusive and therefore specify the presence of features, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, steps, operations, elements, components, and/or groups thereof. The method steps, processes, and operations described herein are not to be construed as necessarily requiring their performance in the particular order discussed or illustrated, unless specifically identified as an order of performance. Additional or alternative steps may be employed.
[0031] When an element or layer is referred to as being “on,” “engaged to,” “connected to,” “attached to,” or “coupled to” another element or layer, it may be directly on, engaged, connected, attached, or coupled to the other element or layer, or intervening elements or layers may be present. In contrast, when an element is referred to as being “directly on,” “directly engaged to,” “directly connected to,” “directly attached to,” or “directly coupled to” another element or layer, there may be no intervening elements or layers present. Other words used to describe the relationship between elements should be interpreted in a like fashion (e.g., “between” versus “directly between,” “adjacent” versus “directly adjacent,” etc.). As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items.
[0032] The terms first, second, third, etc. may be used herein to describe various elements, components, regions, layers and/or sections. These elements, components, regions, layers and/or sections should not be limited by these terms. These terms may be only used to distinguish one element, component, region, layer or section from another region, layer or section. Terms such as “first,” “second,” and other numerical terms do not imply a sequence or order unless clearly indicated by the context. Thus, a first element, component, region, layer or section discussed below could be termed a second element, component, region, layer or section without departing from the teachings of the example configurations.
[0033] With reference to FIGS. 1A and 1B , a vehicle 10 is provided. The vehicle 10 may be any known variety of vehicle, such as a car, a truck, or a van, for example. The vehicle 10 may include a closure 12 and a body assembly 14 . The closure 12 may be movably coupled to the body assembly 14 to allow a user to access, and/or to prevent the user from accessing, a portion of the vehicle 10 . In some configurations, the closure 12 may include a tailgate assembly movably coupled to, and/or supported by, the body assembly 14 . In this regard, the closure 12 may be referred to herein as the tailgate assembly 12 . Accordingly, the tailgate assembly 12 may allow the user to access, and/or restrict the user from accessing, a bed portion 16 of the vehicle 10 .
[0034] With reference to FIGS. 1A-2 , the tailgate assembly 12 may include a pair of tailgate frame members 20 , a latch assembly 22 , and one or more lock assemblies 24 . The tailgate assembly 12 may be coupled to the body assembly 14 for rotation about an axis A 1 . For example, the tailgate frame 20 may be rotatably supported by the lock assemblies 24 relative to the body assembly 14 such that the tailgate assembly 12 rotates between a closed position ( FIG. 1A ) and an open position ( FIG. 1B ). In this regard, opposed ends of the tailgate assembly 12 may each include a tailgate frame member 20 and a lock assembly 24 . The latch assembly 22 may secure the tailgate assembly 12 relative to the body assembly 14 in order to prevent the tailgate assembly 12 from rotating about the axis A 1 from the closed position to the open position. In this regard, as illustrated in FIG. 1A , an authorization and/or authentication system 23 may include an activation device 25 and a control module 26 in communication with the latch assembly 22 and/or the lock assemblies 24 to control a state (e.g., LOCK/UNLOCK) of the latch assembly 22 and the lock assemblies 24 . For example, upon authentication of a valid user and/or a valid activation device 25 , the control module 26 may transmit (e.g., wired or wireless communication) (i) a LOCK/UNLOCK signal 27 a to the latch assembly 22 to prevent and/or allow a user to rotate the tailgate assembly 12 from the closed position ( FIG. 1A ) to the open position ( FIG. 1B and FIG. 4A ) and (ii) a LOCK/UNLOCK signal 27 b to the lock assembly 24 to prevent and/or allow a user to proceed with unlocking the lock assemblies 24 and thereafter remove the tailgate assembly 12 from the vehicle 10 ( FIG. 4B ).
[0035] As illustrated in FIG. 2 , the tailgate frame 20 may include a base 28 and an arm 30 extending from the base 28 such that the frame 20 defines a generally L-shaped construct. The arm 30 may include an aperture 32 . In some configurations the aperture 32 may be disposed proximate the base 28 and may include an elongate shape to receive a portion of the lock assembly 24 . In this regard, the axis A 1 may extend through the aperture(s) 32 .
[0036] A first portion of the lock assemblies 24 may be coupled to the tailgate frame 20 and a second portion of the lock assemblies 24 may be coupled to the body assembly 14 such that the axis A 1 extends through the first and second portions of the lock assemblies 24 . In particular, each lock assembly 24 may include a coupling member or projection 34 disposed within one of the apertures 32 .
[0037] With reference to at least FIG. 2 , the projection 34 may include an outer surface 38 extending from a proximal end 40 to a distal end 42 . The outer surface 38 may include, and/or otherwise be defined at least in part by, a first lateral wall 46 , a second lateral wall (not shown), an upper wall 50 , and a lower wall 52 . The first lateral wall 46 may be opposite the second lateral wall. The lower wall 52 may extend from the first lateral wall 46 to the second lateral wall. The upper wall 50 may be opposite the lower wall 52 and extend from the first lateral wall 46 to the second lateral wall.
[0038] The first lateral wall 46 and the second lateral wall may each include a generally planar construct. In some configurations, the first lateral wall 46 may be parallel to the second lateral wall. The upper and lower walls 50 , 52 may include a generally convex construct such that the projection 34 defines a generally stadium-shaped configuration extending from the proximal end 40 to the distal end 42 .
[0039] With reference to FIGS. 1-3B , the body assembly 14 may include a body 60 , a coupling assembly 62 , and a locking mechanism 64 . The coupling assembly 62 may be coupled directly or indirectly to the body 60 . In an assembled configuration, the projection 34 of the tailgate assembly 12 rotates relative to at least a portion of the coupling assembly 62 , in order to allow the tailgate assembly 12 to rotate between the open position and the closed position. In this regard, while the tailgate assembly 12 and body assembly 14 are shown and described herein as including the locking mechanism 64 and the coupling assembly 62 , respectively, it will be appreciated that the tailgate assembly 12 may include the coupling assembly 62 and/or the locking mechanism 64 , and the body assembly 14 may include the lock assembly 24 , within the scope of the present disclosure (e.g., FIGS. 4A and 4B ).
[0040] The coupling assembly 62 may include a base plate 70 , a support housing 72 , a support plate 74 , a housing or coupling member 76 , and a carriage 78 . The base plate 70 may be coupled to and/or supported by the body 60 and may include one or more mounting features 82 (e.g., apertures) and a housing-receiving feature 84 (e.g., aperture). The mounting features 82 may be sized and shaped to receive a fastener (not shown), such as a bolt, screw, or rivet, for example, to couple the base plate 70 to the body 60 .
[0041] The support housing 72 may include a generally hollow cylinder 88 , a mounting flange 90 , and one or more mounting features 92 (e.g., clips). The cylinder 88 may include a generally cylindrical inner surface 94 , a generally cylindrical outer surface 96 , and one or more engagement features 98 . The engagement feature(s) 98 (e.g., longitudinally extending ribs) may extend radially outward from the outer surface 96 . The mounting flange 90 may extend radially outward from the outer surface 96 . The one or more mounting features 92 (e.g., clips) may extend axially from the mounting flange 90 , away from the cylinder 88 . As illustrated in at least FIGS. 3A and 3B , in the assembled configuration, the mounting features 100 may be disposed within the housing-receiving feature 84 to secure the support housing 72 to the base plate 70 .
[0042] The support plate 74 may include one or more mounting features 104 (e.g., apertures) and a support housing-receiving feature 106 (e.g., an aperture). In the assembled configuration, the mounting feature(s) 104 may be aligned with the mounting feature(s) 82 of the base plate 70 , such that each fastener (not shown) extends through a mounting feature 104 of the support plate 74 and a mounting feature 82 of the base plate 70 , respectively, in order to secure the support plate 74 to the base plate 70 and to secure the base plate 70 to the body 60 . The housing-receiving feature 106 may receive the support housing 72 in order to secure the support housing 72 to the support plate 74 . In this regard, the support housing 72 may be disposed within the housing-receiving feature 106 such that the engagement feature(s) 98 engage the support plate 74 in a press-fit configuration.
[0043] As illustrated in FIG. 2 , the coupling member 76 may include a base portion 108 and a support portion 110 . The base portion 108 may include a support-housing receiving feature 112 (e.g., an aperture). With reference to FIGS. 3A and 3B , in the assembled configuration, the support housing-receiving feature 112 may receive the support housing 72 in order to secure the support housing 72 to the coupling member 76 . In this regard, the support housing 72 may be disposed within the support housing-receiving feature 112 such that the engagement feature(s) 98 engage the coupling member 76 in a press-fit configuration.
[0044] The support portion 110 may extend from the base portion 108 of the coupling member 76 and may define a generally hollow cylindrical construct. In this regard, the support portion 110 may include a cylindrical inner surface 116 and a slot 118 . The inner surface 116 may surround the support-housing receiving feature 112 . The slot 118 may extend through the support portion 110 . As will be explained in more detail below, in the assembled configuration, the slot 118 may allow a user to assemble the tailgate assembly 12 to, and/or remove the tailgate assembly 12 from, the body assembly 14 .
[0045] With reference to FIG. 2 , the carriage 78 may include a proximal end 122 , a distal end 124 opposite the proximal end 122 , a peripheral surface 125 , and a projection-receiving feature 126 (e.g., a slot). As illustrated in FIGS. 3A and 3B , in the assembled configuration, the carriage 78 may be disposed within the coupling member 76 for rotation about the axis A 1 . The peripheral surface 125 may extend from and between the proximal and distal ends 122 , 124 .
[0046] The projection-receiving feature 126 may be formed in one or more of the proximal end 122 and the peripheral surface 125 . In this regard, the projection-receiving feature 126 may include an opening 128 formed in the distal end 124 of the carriage 78 and an opening 130 formed in the peripheral surface 125 of the carriage 78 . In some configurations, the opening 128 and/or the opening 130 may be generally U-shaped such that the opening 128 communicates with and/or opens into the opening 130 . The distal end 124 of the carriage 78 may include an aperture 132 . The aperture 132 may open into and/or communicate with the projection-receiving feature 126 , including the opening 128 formed in the proximal end 122 of the carriage 78 . A size and shape of the projection-receiving feature 126 may correspond to a size and shape of the projection 34 such that the projection 34 can be received by the openings 128 , 130 in order to assemble the projection 34 within, and remove the projection 34 from, the projection-receiving feature 126 .
[0047] As illustrated in FIGS. 3A and 3B , in the assembled configuration, the carriage 78 may be disposed within the coupling member 76 such that the axis A 1 extends through the proximal and distal ends 122 , 124 . In this regard, in some configurations, the axis A 1 may extend through the aperture 132 and the opening 128 . As will be explained in more detail below, the carriage 78 , including the projection-receiving feature 126 and the aperture 132 , may cooperate with the locking mechanism 64 to allow the tailgate assembly 12 to be removed from, and/or to prevent the tailgate 18 from being removed from, the body assembly 14 .
[0048] With reference to FIG. 2 , the locking mechanism 64 may include a housing 136 , a power source 137 , a driver 138 , a drivetrain 140 , a lock member 142 , and an activation member 143 . The housing 136 may include a first portion 144 and a second portion 146 .
[0049] The first portion 144 of the housing 136 may include a cavity 148 and a track 150 . In some implementations, the track 150 includes a first guide surface 152 and a second guide surface 154 . The first guide surface 152 may extend in a direction substantially parallel to the second guide surface 154 , such that the first and second guide surfaces 152 , 154 define a channel 156 therebetween. In some configurations, the first and second guide surfaces 152 , 154 may arcuately extend from a proximal end 158 of the track 150 to a distal end 160 of the track 150 . In this regard, the first guide surface 152 may define a convex construct extending from the proximal end 158 to the distal end 160 , and the second guide surface 154 may define a concave construct extending from the proximal end 158 to the distal end 160 . The proximal and distal ends 158 , 160 may define an opening 161 extending therebetween. The distal end 160 may include an aperture 162 in communication with the channel 156 .
[0050] The second portion 146 of the housing 136 may include a cavity 164 and a track 166 . In some implementations, the track 166 includes a first guide surface 168 and a second guide surface (not shown). The first guide surface 168 may extend in a direction substantially parallel to the second guide surface, such that the first guide surface 168 and the second guide surface define a channel 172 therebetween. In some configurations, the first guide surface 168 and the second guide surface may arcuately extend from a proximal end 174 of the track 166 to a distal end 176 of the track 166 . In this regard, the first guide surface 168 may define a convex construct extending from the proximal end 174 to the distal end 176 , and the second guide surface may define a concave construct extending from the proximal end 174 to the distal end 176 . The proximal and distal ends 174 , 176 may define an opening 178 extending therebetween.
[0051] The power source 137 may be disposed within the housing 136 to provide power to the driver 138 . In this regard, the power source 137 may include a battery. It will be appreciated, however, that the locking mechanism 64 and the driver 138 may receive power from another source, such as the battery (not shown) of the vehicle 10 . As will be explained in more detail below, the driver 138 may include any device and/or assembly that can selectively move the lock member 142 along the arcuate track 150 (e.g., about the axis A 1 ). For example, the driver 138 may include a motor, a solenoid, a pneumatic actuator, or other device that can apply a force on the lock member 142 in a direction substantially tangential to the arcuate track 150 .
[0052] The drivetrain 140 may include one or more drive members 180 - 1 , 180 - 2 , . . . 180 - n and a coupling member 182 . In some implementations, the drive members 180 - 1 , 180 - 2 , . . . 180 - n include five gears intermeshed with one another, such that a rotation of a first drive member 180 - 1 causes a rotation of a fifth drive member 180 - 5 . In this regard, the driver 138 may rotate the first drive member 180 - 1 , which may, in turn, rotate the other drive members 180 - n. At least one of the drive members 180 - n may include a coupler 184 . For example, as illustrated in FIG. 2 , in some implementations, a fifth drive member 180 - 5 may include the coupler 184 . The coupler 184 may be disposed at a center of the drive member 180 - n. In this regard, the coupler 184 may be substantially aligned with an axis of rotation of the drive member 180 - n. The coupler 184 may include one of a recess (e.g., an aperture or hub) and an axle. In some implementations, the coupler 184 includes an aperture 184 having an X-shape. While the drivetrain 140 is generally shown and described herein as including five drive members 180 - 1 , 180 - 2 , . . . 180 - n, the drivetrain 140 may include more or less than five drive members 180 - 1 , 180 - 2 , . . . 180 - n within the scope of the present disclosure.
[0053] The coupling member 182 may extend from a proximal end 186 to a distal end 188 . The proximal end 186 may include a first coupler 190 , and the distal end 188 may include a second coupler 192 . The first coupler 190 may include one of a recess (e.g., an aperture or hub) and an axle. As illustrated in FIG. 2 , in some implementations, the first coupler 190 includes a substantially X-shaped axle. The second coupler 192 may include one of a recess (e.g., an aperture or hub) and an axle. As illustrated in FIG. 2 , in some implementations, the second coupler 192 includes an axle (e.g., a cylindrical pin).
[0054] The lock member 142 may include a lock portion 194 and a coupling portion 196 . The lock portion 194 may include a first guide surface 198 and a second guide surface 200 . The first guide surface 198 may extend in a direction substantially parallel to the second guide surface 200 . In some configurations, the first and second guide surfaces 198 , 200 may arcuately extend from a proximal end 202 of the lock portion 194 to a distal end 204 of the lock portion 194 . In this regard, the first guide surface 198 may define a concave construct extending from the proximal end 202 to the distal end 204 , and the second guide surface 200 may define a convex construct extending from the proximal end 202 to the distal end 204 .
[0055] The coupling portion 196 may extend radially outward from the lock portion 194 . In this regard, in some implementations, the coupling portion 196 includes a proximal end 206 supported by the lock portion 194 , and a distal end 208 radially offset from the lock portion 194 . The coupling portion 196 may include a coupler 210 . The coupler 210 may include one of a recess (e.g., an aperture or hub) and an axle. As illustrated in FIG. 2 , in some implementations, the coupler 210 includes an elongated aperture or slot.
[0056] In an assembled configuration, the first portion 144 of the housing 136 may be coupled to the second portion 146 of the housing 136 , such that the cavity 148 and track 150 of the first portion 144 are aligned with the cavity 164 and track 166 of the second portion. The driver 138 , drivetrain 140 , and lock member 142 may be supported by at least one of the first portion 144 and second portion 146 of the housing 136 . For example, the driver 138 and drivetrain 140 may be disposed within at least one of the cavity 148 of the first portion 144 and the cavity 164 of the second portion 146 . Each of the drive members 180 - 1 , 180 - 2 , . . . 180 - n may include a first rotation feature 212 - 1 , 212 - 2 , . . . 212 - n (e.g., a hub or an axle), and at least one of the first and second portions 144 , 146 of the housing 136 may include a second rotation feature 214 - 1 , 214 - 2 , . . . 214 - n (e.g., a hub or an axle) rotatably coupled to a corresponding one of the first rotation features 212 - 1 , 212 - 2 , . . . 212 - n. As illustrated in FIG. 2 , the first drive member 180 - 1 may be coupled to the driver for rotation therewith. The coupling member 182 may be supported by one of the drive members 180 - 1 , 180 - 2 , . . . 180 - n and the lock member 142 . For example, in some implementations, the coupling member 182 is supported by the fifth drive member 180 - 5 for rotation therewith. In this regard, the first coupler 190 of the coupling member 182 may be coupled to the coupler 184 of the fifth drive member 180 - 5 . The second coupler 192 may be coupled to the coupler 210 of the lock member 142 . For example, the second coupler 192 (e.g., a pin, as previously described) may be translatably and rotatably disposed within the coupler 210 (e.g., an aperture, as previously described).
[0057] The lock member 142 may be supported by at least one of the track 150 of the first portion 144 and the track 166 of the second portion 146 . For example, the lock member 142 may be disposed within the channel 156 of the track 150 and/or the channel 172 of the track 166 . In some implementations, the first guide surface 198 of the lock member 142 may be adjacent to, and/or slidably engage, the first guide surface 152 of the track 150 and/or the first guide surface 168 of the track 166 , and the second guide surface 200 of the lock member 142 may be adjacent to, and/or slidably engage, the second guide surface 154 of the track 150 and/or the second guide surface of the track 166 . In this regard, as will be explained in more detail below, the lock member 142 may be disposed within, and/or extend through, the aperture 162 of the first portion 144 of the housing 136 such that during operation of the locking mechanism 64 , the lock member 142 translates and/or rotates relative to the housing 136 between a locked state ( FIG. 3A ) and an unlocked state ( FIG. 3B ). In the locked state, the lock member 142 may be disposed within the openings 161 and/or 178 defined by the first portion 144 and/or second portion 146 , respectively, of the housing 136 . In this regard, the lock member 142 may move along an arcuate path or axis A 2 between the locked state and the unlocked state. As illustrated in FIGS. 3A and 3B , the axis A 2 may be defined by at least one of the lock member 142 and/or the tracks 150 , 166 , and may be concentrically disposed about the axis A 1 .
[0058] The activation member 143 may include a button, switch, or other suitable device for communicating with the driver 138 . As illustrated in FIG. 2 , the activation member 138 may be disposed on an outer surface of the second portion 146 of the housing 136 . As will be explained in more detail below, the activation member 143 may include a button that, when pressed, transmits an activation or wake-up signal to a portion of the authentication system 23 . For example, the activation member 143 may transmit a wake-up signal to the controller 26 .
[0059] With continued reference to FIGS. 3A-3B , operation of the tailgate assembly 12 will now be described. In a first state, the tailgate assembly 12 may be coupled to the body assembly 14 in a closed position ( FIG. 1A ) or an open position ( FIG. 1B ), and the locking mechanism 64 may be supported by, and/or coupled to, one of the tailgate assembly 12 and the body assembly 14 , such that the openings 161 and/or 178 are aligned with the slot 118 of the coupling member 76 and the opening 130 of the carriage 78 . The lock member 142 may extend from the aperture 162 to cover, or otherwise block, at least a portion of the slot 118 , the opening 130 , and/or the openings 161 , 178 to secure the projection 34 within the projection-receiving feature 126 of the carriage 78 ( FIG. 3A ). Accordingly, the lock member 142 may prevent movement of the tailgate assembly 12 relative to the body assembly 14 in a direction generally perpendicular to the axis A 1 , while still allowing rotational movement of the tailgate assembly 12 relative to the body assembly 14 about the axis A 1 .
[0060] In order to unlock the tailgate assembly 12 relative to the body assembly 14 (e.g., in order to remove the tailgate assembly 12 from the body assembly 14 ), the user may wake-up the authentication system 23 (e.g., the controller 26 ) and/or the locking mechanism 64 (e.g., the driver 138 ) by pressing the activation member 143 . For example, the activation member 143 may transmit a wake-up signal to the controller 26 through a wired or wireless communication protocol, such that the controller 26 transitions from a dormant or sleep state to an active or awake state. Within a predetermined period of time T 1 , the user may use the authentication system 23 to actuate the driver 138 . The predetermined period of time T 1 may be between 20 seconds and 120 seconds, as determined or otherwise measured by a timer (not shown) and/or a capacitive charger (not shown) disposed within the vehicle 10 . In some implementations, the predetermined period of T 1 may be equal to 60 seconds. In this regard, the user may actuate the driver 138 using the activation device 25 (e.g., a mechanical activation device, such as a key, for example, or an electronic activation device, such as a key FOB, a phone, or a switch, for example). In one configuration, a user may utilize a key FOB to transmit a signal to the control module 26 . Upon authenticating the activation device 25 , the control module 26 may transmit an UNLOCK signal 27 b to the lock assembly 24 and actuate the driver 138 in order to allow a user to remove the tailgate assembly 12 from the vehicle 10 . If the user does not use the authentication system 23 to actuate the driver 138 within the predetermined period of time T 1 , the authentication system 23 (e.g., the controller 26 ) and/or the locking mechanism 64 (e.g., the driver 138 ) may transition to the dormant state.
[0061] Actuating the driver 138 causes the first drive member 180 - 1 and various other drive members 180 - 2 , 180 - 3 , 180 - 4 , 180 - 5 to rotate relative to the housing 136 . As the drive members 180 - 1 , 180 - 2 , 180 - 3 , 180 - 4 , 180 - 5 rotate, the coupling member 182 likewise rotates, thereby causing the second coupler 192 to translate and rotate within and relative to the coupler 210 from the distal end 208 of the coupler 210 to the proximal end 206 of the coupler 210 . Translation and/or rotation of the second coupler 192 within the coupler 210 causes the lock member 142 to move along the axis A 2 relative to the housing 136 and into an unlocked position ( FIG. 3B ) such that the slot 118 of the coupling member 76 and the opening 130 of the carriage 78 are not covered by the lock member 142 . In this regard, in the unlocked position, the lock member 142 may be disposed within the channels 156 , 176 of the housing 136 .
[0062] Once the slot 118 of the coupling member 76 and the opening 130 of the carriage 78 are not covered and/or blocked by the lock member 142 , the user may move the projection 34 and, thus, the tailgate assembly 12 in a direction generally perpendicular to the axis A 1 . For example, with reference to FIG. 4B , the user may lift and remove the tailgate assembly 12 relative to the body assembly 14 such that the projection 34 (i) exits the projection-receiving feature 126 of the carriage 78 through the opening 130 and (ii) exits the coupling member 76 through the slot 118 . If the user does not remove the tailgate assembly 12 from the body assembly 14 within a predetermined amount of time T 2 (e.g., more than the predetermined amount of time T 1 and less than eight hours), the driver 138 may move the lock member 142 from the unlocked position ( FIG. 3B ) to the locked position ( FIG. 3A ), in the manner described above.
[0063] The foregoing description has been provided for purposes of illustration and description. It is not intended to be exhaustive or to limit the disclosure. Individual elements or features of a particular configuration are generally not limited to that particular configuration, but, where applicable, are interchangeable and can be used in a selected configuration, even if not specifically shown or described. The same may also be varied in many ways. Such variations are not to be regarded as a departure from the disclosure, and all such modifications are intended to be included within the scope of the disclosure. | A system for securing a tailgate to a vehicle body includes a housing secured to one of the tailgate and the vehicle body, the housing including a passageway. A projection is secured to the other of the tailgate and the vehicle body and is rotatably received by the housing in an attached state to rotatably attach the tailgate to the vehicle body and is separated from the housing in a detached state to permit removal of the tailgate from the vehicle body. The system also includes a locking mechanism operable in a locked state to block the passageway and prevent movement of the projection from the attached state to the detached state and an unlocked state opening the passageway to permit movement of the projection from the attached state to the detached state. | 4 |
TECHNICAL FIELD
The present invention relates to a yarn feeding apparatus for a knitting machine and, more particularly, to a yarn feeding apparatus which, in response to abnormal tension on the yarn, allows a yarn loop wound on a storage drum to be unwound, and then halts operation of the machine, whereby the yarn will not break, and thus yarn feeding can be readily resumed.
BACKGROUND ART
In general, a knitting machine includes a number of yarn feeding apparatuses corresponding to the number of bobbins in order to feed each yarn as it is unwound from each bobbin to knitting needles within the interior of the knitting machine. An example of such a yarn feeding apparatus is disclosed in Korean Patent Publication No. 86-1053. Such apparatus has a storage drum equipped with a driving wheel driven by an endless tape. A number of conical surfaces are provided coaxially with each other at the upper and lower portions of a holder. Winding and unwinding is simultaneously executed to wind each yarn a predetermined number of turns around a storage drum.
In such an apparatus, the yarn arranged on the storage drum smoothly feeds yarn to the interior of the knitting machine. However, since an operator winds the yarn one-by-one on the storage drum to form each yarn loop, not only is the work cumbersome, but it also causes feeding tension differences in each yarn where the number of turns of yarn formed on each storage drum are different from each other.
In presently known and used yarn feeding apparatus, when abnormal tension is imparted to the yarn which is being unwound from the bobbin due to any defect in the bobbin itself, there is no mechanism capable of absorbing the increased tension. Therefore, the yarn will often break easily.
Further, when it is desired to change over from a positive type feeding to a free feeding to accommodate a switch in textile structure, generally, either a driving belt wound on the driving wheel is manually removed, or a locking device mounted on each driving wheel is handled one-by-one to allow the storage drum to be freely rotated. However, since these changeover processes are cumbersome and difficult to automate, there has been a problem that productivity is reduced.
SUMMARY OF THE INVENTION
Therefore, the present invention provides a yarn feeding apparatus for a knitting machine in which a rotary cap driven by a motor is provided on an upper part of a storage drum. The structure is such that, when an abnormal tension is imparted to the yarn fed thereto, the yarn loop wound on the storage drum unwinds, and, simultaneously, the driving of the machine is stopped, so that the yarn feeding can be executed without breaking or disconnecting the yarn.
The present invention also provides a yarn feeding apparatus for a knitting machine in which an idle pulley is provided adjacent to the bottom of a driving wheel. A shifting mechanism for shifting a driving belt to either the driving wheel or the idle pulley is provided at one side. The shifting mechanism serves to change the yarn feeding condition between positive feeding or free feeding under motor control.
According to one embodiment of the present invention, a hollow shaft is fixed at the central portion of the base of a hollow holder The holder is equipped with a clamper at a side of the holder. A driving wheel equipped integrally with a storage drum above it is rotatably mounted via a bearing to the hollow shaft. A cylindrical mounting member is attached to the top end of the hollow shaft to support a motor in the interior of the mounting member, whereby it is located at the inside of the storage drum. A hollow threaded tube formed with female threads on the internal circumferential surface is fixed on the upper surface of the motor, and a coupling member having a rectangular section is fixed to the rotary shaft of the motor. A movable threaded tube formed with male thread on the external circumferential surface thereof and having a rectangular groove to be coupled with the coupling member fixed to the rotary shaft of the motor is engaged with the hollow threaded tube. A rotary cap having a semispherical surface at an upper end portion is fixed to the top end of the movable threaded tube. A protrusion having a yarn-inducing hole is provided on a side of the semispherical surface of the rotary cap, and another yarn-inducing hole is provided at the bottom end portion of the rotary cap directly below the protrusion, whereby it is made such that the yarn to be passed through the first and second yarn-inducing holes is made to be wound on the storage drum in response to the rotation of the rotary cap. A push button switch is provided at the neck portion of the hollow holder. The rotary cap is moved to its upper position according to the rotation of the motor, the switch button is pressed by the protrusion of the rotary cap, and in response thereto, the apparatus stops rotation of the rotary cap and simultaneously causes the driving wheel and the storage drum to rotate by applying driving force to the driving belt and thereby the feeding of yarn is executed. By rotating the cap until it moves from its lower position to the upper position, the protrusion will press the button portion of the push button switch. The rotary cap has, at this time, wound yarn onto the drum in an amount determined by the turning number of the rotary cap between the lower and upper positions. The driving of the knitting machine is started when the rotary cap is stopped due to the switch. Thereafter, the amount of yarn wound on the storage drum is maintained as yarn feeding continues as the knitting machine pulls on the yarn. When an abnormal tension is imparted to the yarn being supplied in this state, e.g., due to phenomena occurring at the bobbin, the protrusion of the rotary cap is released from the push button switch due to the tensional force, and then the storage drum and the rotary cap are simultaneously rotated, and thereby the yarn loop formed on the storage drum becomes unwound, whereby the feeding of yarn to the machine continues to be executed. Simultaneously with this, since the pressed state of the button portion of the push button switch becomes released, the operation of the knitting machine is stopped, whereby breaking of the yarn can be prevented by stopping the knitting machine before all of the yarn wound on the drum is used up.
A preferred embodiment of the present invention as above is for constant feeding of yarn, but according to another embodiment of the present invention, the yarn can be freely fed upon knitting of tissue, such as a jacquard tissue, only by adding simple components. That is, the feeding apparatus is adapted such that the bottom end portion of the hollow shaft is extended, and an idle pulley is provided between the driving wheel and base portion of the holder. A driving belt shifting pulley to be shifted by a motor capable of rotating in normal and reverse directions is provided at an appropriate position. For constant feeding of yarn, the driving belt is made to be wound on the driving wheel, and for free feeding of yarn, the driving belt shifting pulley is made to be dropped down by the rotation of a motor, whereby the driving belt is made to be wound on the idle pulley, so that the storage drum can be freely rotated according to the pulling force of the knitting machine itself.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side view of a yarn feeding apparatus according to a preferred embodiment of the present invention adapted for use with a knitting machine;
FIG. 2 is a longitudinal cross-sectional view of FIG. 1;
FIG. 3 is a longitudinal cross-sectional view of a yarn feeding apparatus according to a preferred embodiment of the present invention showing a state where yarn is being fed during operation of the knitting machine; and
FIGS. 4 and 5 are schematic explanatory diagrams of a yarn feeding apparatus according to another embodiment of the present invention, in which FIG. 4 is a side view showing the apparatus during feeding of the yarn, and FIG. 5 is a side view showing the apparatus during free feeding of the yarn.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Hereinafter, the preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings In the drawings, i.e., FIGS. 1-3, a yarn feeding apparatus has a clamper 12 for fixing a hollow holder 10 to a supporting ring 11 of a knitting machine. The clamper is provided at a vertical position at one side of the yarn feeding apparatus. The apparatus also has a hollow shaft 14 which is fixed at its bottom end to a central side of a base 13 by a nut 17 acting through washers 15 and 16. A driving wheel 20, having upper and lower flanges 20a and 20b, is rotatably mounted to the hollow shaft 14 at the top side of base 13 via a bearing 18. A storage drum 22 has conical surfaces 22a and 22b and is provided with a number of pins 21 ("spinning pins") at predetermined intervals on the external surface thereof to assist in supporting yarn on the drum. The drum 22 is formed integrally with the driving wheel 20.
A mounting member 19 of cylindrical shape is attached to the top end portion of hollow shaft 14, and a motor 23 is inserted and fixed within the interior of the mounting member so as to be located within the interior of the storage drum 22. A hollow threaded tube 23, having a female thread portion on its internal circumferential surface, is fixed on the top surface of the motor 23, and a coupling member 25 having rectangular section is attached to a rotary shaft 23a of the motor. A movable threaded tube 26, formed with a male thread portion on its external circumferential surface and having a rectangular groove 26b to be coupled with said coupling member 25 at the internal circumferential surface of the tube 26, is coupled at its external surface with the hollow threaded tube 24.
A rotary cap 27, having a semispherical-shaped surface at its top end, is fixed to the top end of the movable threaded tube 26 such that the rotary cap 27 almost surrounds the storage drum 22 when the movable threaded tube 26 is completely threaded onto the hollow tube 24. A protective cap 28, having a slightly larger diameter than the hollow threaded tube 24 and having a length about equal to that of the movable threaded tube 26, is fixed to the inner side of the rotary cap 27 in order to prevent any extraneous substances, such as dust, from entering the threaded portion of the movable threaded tube 26. Stops 24a and 29a are respectively formed at a top end portion of the hollow threaded tube 24 and at a washer 29 fixed to the front end side of the movable threaded tube 26 in order to limit the lower movement of the cap 27. A protrusion 30, having a third yarn-inducing hole 30a, is provided at a side of the semispherical surface of the rotary cap 27, and a fourth yarn-inducing hole 31 is provided at the bottom end of the rotary cap 27 substantially vertically below protrusion 30.
A push button switch 33 protrudes inward from a neck portion of hollow holder 10. A knob 32 is also provided at the neck portion of the hollow holder 10 to adjust how much button 33 protrudes. When the button of the switch 33 is contacted and depressed by the protrusion 30 of the rotary cap 27, rotation of the rotary cap is stopped. Simultaneously, the driving of the knitting machine is started, and then the driving wheel 20 and the storage drum 22 are rotated according to the driving force of the driving belt 34, so that the yarn is fed. A yarn stopper 35 is provided at the front end portion of the hollow holder 10, and first and second yarn-inducing holes 36 and 37 located on the rotational center of the rotary cap 27 are arranged at upper and lower sides of the yarn stopper 35, and a yarn-running sensor 39 and a yarn-stopping sensor 40 are respectively provided at the neck portion and the vertical portion of the hollow holder 10. A fifth yarn-inducing hole 41 receives the end of the yarn which has passed through the first, second, third, and fourth yarn-inducing holes 36, 37, 30a, and 31 and which has been wound on the storage drum 22. This end of the yarn passes through hole 41 to the interior of the knitting machine.
A signal lamp 42 is provided so that when a yarn becomes disconnected or its feeding stops, the lamp indicates such disconnection or stoppage. A terminal jack 43 is provided electrically connecting push button switch 33, yarn-running sensor 39, yarn-stopping sensor 40, and motor 23 to a central control unit provided in the main body of the knitting machine.
In the above embodiment, the upper and lower conical surfaces 22a and 22b of the storage drum 22 are shown as formed on the storage drum itself, but they also may be formed by bending the upper and lower end portions of the pins 21 so as to have an appropriate slant angle. It is also possible to eliminate the pins 21 by integrally forming a concave and convex portion on the surface of the storage drum 22 of the same shape as the pins 21, respectively.
The motor 23 for rotating cap 27 is a DC motor capable of normal and reverse rotation and preferably is one that can be driven selectively by electric power of 6V, 9V, 12V, or 24V, according to the kind of yarn to be fed. The stops 24a and 29a formed on the fixed washer 29 of the movable threaded tube 26 and the top end portion of the hollow threaded tube 24, respectively, are desirable to be formed so that the fourth yarn-inducing hole 31 of the rotary cap 27 is located at a closest position to the fifth yarn-inducing hole 41 on the holder 10 when the rotary cap 27 is located at the lower position, that is, when the stops 24a and 29a contact each other.
The operational condition and effect of the yarn feeding apparatus according to a preferred embodiment of the present invention having the construction as above will be described in detail hereinafter.
When the knitting machine is in a stopped state, the rotary cap 27 is located at a lower position, as shown in FIGS. 1 and 2. At this time, the yarn from the bobbin is connected to the interior of the knitting machine through the first and second yarn-inducing holes 36 and 37 of the holder 10, the third and fourth yarn-inducing holes 31a and 31 provided at the protrusion 30 and the lower peripheral portion of the rotary cap 27, and the fifth yarn-inducing hole 41 of the holder 10. In this state, when electric power supply is fed from the central control unit of the knitting machine to the motor 23 to rotate the motor 23, the movable threaded tube 26 and the rotary cap 27 are rotated and move upward, and thereby wind the yarn onto the storage drum 22, thus forming yarn loops corresponding to the number of turns of the cap 27. The motor 23 is stopped at the moment that the rotary cap 27 has executed a predetermined number of rotations, i.e., when the protrusion 30 formed on the semispherical surface contacts the button portion of the push button switch 33 mounted on the neck portion of the holder 10, and thereby the protrusion 30 of the rotary cap 27 presses the push button switch 33. In response, the central control unit of the knitting machine drives the knitting machine. The driving force of the knitting machine is transmitted to the driving wheel 20 through the driving belt 34, whereby the driving wheel 20 and the storage drum 22 are simultaneously rotated. This causes the yarn to be constantly fed into the interior of the knitting machine. At this moment, since the driving wheel 20 and the storage drum 22 are rotated while the rotary cap 27 is stopped, the yarn being wound from the storage drum 22 is simultaneously replaced with yarn being wound onto the drum, due to the rotation of the drum.
For the number of turns of such yarn wound on the drum, i.e., the yarn to be wound on the storage drum 22, adjustment is possible according to the desired requirements. That is, the upper limit of movement of the rotary cap 27 can be appropriately selected by adjusting the amount of protrusion of the push button switch 33 by using knob 32. Generally, even though the desired total length of the yarn wound around the storage drum 22 may vary, depending upon the kind or strength of the yarn, it will usually be sufficient if the total length is approximately 1.5 m. If the circumference of the storage drum 22 is approximately 15 cm, to obtain the 1.5 m of yarn on the drum, the cap must rotate ten times. Therefore, the button portion of the push button switch 33 and the protrusion 30 of the cap 27 are made to contact at an upper position corresponding to about 10 turns from the lower position of the cap 27.
As described above, as the yarn is being fed to the knitting machine, if a tension of more than a predetermined amount is imparted to the feeding yarn due to a defect at the bobbin, the protrusion 30 of the rotary cap 27 is pulled away from the push button switch 33 by the yarn pulling force of the knitting machine itself, due to the loss of slack in the yarn from the bobbin. The rotary cap 27 will thus rotate together with the storage drum 22. In this state, substantially no new yarn will be wound on the storage drum 22, so the amount of yarn wound on the drum will be reducing as the knitting machine uses it up. As can be seen, even though the yarn feeding to the storage drum 22 has stopped, the yarn feeding to the interior of the knitting machine is not instantly stopped. As noted above, simultaneously with the reduction in yarn on the drum, the rotary cap 27 rotates in reverse direction (relative to the above description of initial winding of yarn onto the drum), so the cap 27 moves to the lower position. Accordingly protrusion 30 comes free from the push button switch 33. Therefore, the switch 33 returns to the OFF state, whereby the driving of the knitting machine is stopped by the central processing unit. The abnormal tension being imparted to the feeding yarn is usually due to phenomena that cause the yarn wound on the bobbin to instantaneously stop unwinding. As noted above, if this tension is sufficient, the cap 27 will be pulled and will rotate to move downward, thus causing the knitting machine to stop. To restart the machine, motor 23 is pulsed toward the upper position. Therefore, an electric current of 6V, 9V, 12V, or 24V is fed again from 2 to 3 times for about 1.5 seconds each time (under the control of the central control unit). Thus, after 4-5 seconds elapses from stoppage of the knitting machine, i.e., after two to three pulses, if the tension imparted to the yarn was due to a simple defect of the bobbin, the yarn will not break and will be quickly loosened by the pulsing, and will re-feed so that cap 27 moves upward again to contact the protrusion 30 and switch 33, thereby automatically resuming an operating condition of the knitting machine. However, when the abnormal tension persists, even after stoppage of the knitting machine, and after the above pulsing, a signal lamp 42 is lit, and at the same time, a signal tone is sounded to thereby prompt an operator to manually check the feeding condition of the yarn.
In the above description, the driving voltage fed to the motor 23 is selectively determined, depending upon the kind and strength of the yarn. For a yarn which is weak in strength, such as cotton yarn, a weak voltage of about 6V is fed. For a yarn which is relatively strong, such as polyethylene yarn, a strong voltage of about 12V or 24V is used.
According to a preferred embodiment of the present invention as above, automation is possible for the operation of forming the yarn loop on the storage drum by rotating the rotary cap by utilizing a motor. Therefore, no one-by-one manual operation is required. Further, when an abnormal tension is imparted to a feeding yarn, the rotary cap and the storage drum are made to be simultaneously rotated, and thereby the yarn wound on the storage drum unwinds to alleviate the tension. If the tension remains, the knitting machine will automatically be stopped in response to downward movement of the cap. Thereafter, if there is still abnormal tension, the motor will be pulsed to eliminate it. If the tension still remains, the feeder indicates this. Therefore, poor knitting is minimized or avoided by minimizing or avoiding breakage of the yarn.
Hereinafter another embodiment of the present invention will be described in detail with reference to FIGS. 4 and 5. In the drawings, for the simplicity of expression, diagrams of such parts having the same construction as in the first embodiment of the present invention are omitted, and components which are the same as in the first embodiment are represented by the same reference numerals.
As shown in FIGS. 4 and 5, an idle pulley 43 is provided via a bearing (not shown) coaxially with the driving wheel 20 at the extended end portion of hollow shaft 14, and a reduction motor 50, capable of normal and reverse rotation and having a screw shaft 51, is mounted at one side thereof. A U-shaped support frame 52 is coupled to screw shaft 51, and a shifting wheel 54 guided by a guide shaft 53 is mounted to the interior of a support frame 52. Annular flanges 54a and 54b are provided respectively to the wheel 54 so that the driving belt 34 will not be removed therefrom when shifting the driving belt to either the driving wheel or the idle pulley 43 by the rotation of the reduction motor 50. The driving wheel 20 and the idle pulley 43 are not equipped with any flanges at their adjacent portions so that the shifting of the driving belt 34 is smooth.
This embodiment is applicable when free feeding of the yarn is required in order to change the fiber tissue. For example, if a constant feeding of the yarn is required, such as for plain tissue, the driving belt 34 is wound on the driving wheel 20, as shown in FIG. 4, and when free feeding of the yarn is required, such as for jacquard tissue, the shifting wheel 54 is made to drop down by driving the reduction motor 50, so that the driving belt 34 is removed from the driving wheel and is wound on the idle pulley 43. Therefore, the storage drum 22 is free, thereby enabling free yarn feeding in response to the pulling force of the knitting machine itself.
In this embodiment, not only is the shifting of the constant feeding and free feeding of the yarn simple and convenient but also it helps further automate the knitting machine. | Yarn feeding apparatus for a knitting machine in which a rotary cap driven by a motor is provided at the top of a storage drum. Optionally, an idle pulley may also be provided adjacent the lower portion of a driving wheel and a mechanism for shifting the driving belt alternately between the driving wheel or idle pulley, so that the driving of the machine is stopped in case of abnormal tension imparted to a feeding yarn. Shifting to either constant feeding or free feeding of yarn is possible to be executed automatically. Automation is possible for work for forming the yarn loop on the storage drum without requiring manual operation one-by-one by an operator. Therefore, it helps avoid poor knitting quality and thus avoids cutting off the yarn. It serves to automate the knitting machine so that constant feeding and free feeding of yarn are simply and conveniently executed. | 3 |
FIELD OF THE INVENTION
This invention relates to lithography systems for exposing large substrates at high imaging resolution and high exposure throughputs, and specifically relates to a scan-and-repeat patterning system that employs a unitary mask-substrate stage and enables projection imaging of a substrate with capability to control the image magnification to compensate for changes of substrate dimensions occurring as a result of previous process steps.
BACKGROUND OF THE INVENTION
One of the co-inventors of this application has previously disclosed several large-area patterning systems (U.S. Pat. Nos. 4,924,257; 5,285,236 and 5,291,240). In these previous inventions, this co-inventor, K. Jain, has disclosed projection imaging apparatus for manufacturing a variety of products, including integrated circuits on silicon wafers, flat-panel displays on glass substrates, and multi-chip modules and printed circuit boards on laminate substrates. In a co-pending application (Ser. No. 08/506,232), co-inventor Jain has also described a high-throughput projection imaging system for patterning large, flexible, roll-fed substrates. Some of the projection imaging systems described in the cited patents and patent application have an image magnification of unity (i.e., feature sizes at the mask are equal to corresponding feature sizes at the substrate) whereas others are reduction imaging systems in which each mask feature size is a multiple of the corresponding substrate feature size. The 1:1 magnification systems described in the above patents and patent application also incorporate a single scanning stage on which both the mask and the substrate are rigidly mounted. The reduction systems of prior art employ two independent stages--one for holding and scanning the mask and the other for holding and scanning the substrate.
Whereas the single-stage scan-and-repeat systems have the advantages of elegance of system design and lower system cost, a disadvantage is their inability to provide any image magnification control capability, which stems from the fact that the mask and substrate are rigidly mounted on a single stage. On the other hand, a scanning reduction system employing independent mask and substrate stages can provide magnification adjustment capability, but is significantly more costly due to higher system complexity which results from the requirement of synchronizing the scanning motions (at different velocities due to the non-unity image magnification) of two mechanically independent stages.
In numerous applications of large-area patterning systems, the preferred image magnification is 1:1, which makes several of the projection systems described in the cited patents very attractive. However, in some applications, the size of the substrate may change slightly due to various thermal and/or chemical processing steps. To compensate for scale changes of the substrate, the magnification of the imaging system must vary slightly from unit magnification (typically by a fraction of a percentage) so that a layer already patterned on the substrate will have, after processing, proper image registration with the subsequent layer.
Thus, it becomes highly desirable to develop an apparatus that can exploit the design and cost benefits of 1:1 large-area, scan-and-repeat projection imaging, and at the same time, can enable fine adjustment of the image magnification for optimum lithographic performance.
SUMMARY OF THE INVENTION
For lithographic patterning of large-area substrates at high throughput, it is desirable to use a large-format scanning exposure system with unit magnification. In such a system, it is further desirable to have the capability to control the image magnification to compensate for changes of substrate dimensions occurring as a result of previous process steps. The object of this invention is to provide fine adjustment to unit magnification in a large-area, scan-and-repeat projection imaging apparatus.
Another object of the invention is to combine optical correction with mechanical correction to compensate for small dimensional changes of the substrate. The optical system will provide symmetric or anamorphic magnification control, and the scanning stage will employ an auxiliary-stage-on-primary-stage mechanism to provide a dynamic fine differential motion of the substrate relative to the mask during scanning. The combination of optical and mechanical correction will allow for changes in magnification without degradation of the image during scanning.
An advantage of the invention is that it permits subsequent imaging of a previously imaged substrate section by the same imaging apparatus, even though the substrate size parameters may have been changed slightly during the previous processing.
Another advantage of the invention is that it reduces the tolerances on substrate dimensions since the substrates do not need to be an exact dimensional match to each other nor to the mask.
Still another advantage of the invention is that it permits anamorphic variation of magnification, to allow for differing scale changes in the directions parallel and perpendicular to the scanning direction.
Other objects, features and advantages of the invention will be apparent to those skilled in the art from the following description of the invention and the attached drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a semi-schematic illustration in elevation view of a portion of the new patterning system employing a unitary mask-substrate stage, showing projection imaging of a region on a mask, illuminated from below, onto a corresponding substrate region.
FIG. 2 is a perspective view of the patterning system of FIG. 1.
FIG. 3 describes the seamless scan-and-repeat technique, where successive scans of a hexagonal illumination pattern are suitably overlapped to provide a uniform exposure dose over the entire patterning area.
FIG. 4 is a perspective drawing showing two adjacent, overlapping scans of the hexagonal illumination region on a panel-size segment of a continuous, roll-fed, flexible substrate.
FIG. 5 shows how an image of a feature within the non-overlapping portion of the illumination region is properly registered with an image of the same feature a short time later during scanning when the mask and substrate are scanned at the same speed and the magnification is precisely unity.
FIG. 6 shows how the two images described in FIG. 5 will fail to register if the mask and substrate are scanned at the same speed and the magnification deviates slightly from unity.
FIG. 7 shows how an image of a feature within the overlapping portion of the illumination region is properly registered with an image of the same feature produced during an adjacent scan when the mask and substrate are scanned at the same speed and the magnification is precisely unity.
FIG. 8 shows how the two images described in FIG. 7 will fail to register if the mask and substrate are scanned at the same speed and the magnification deviates slightly from unity.
FIG. 9 illustrates an embodiment of the patterning system with an auxiliary stage mounted to the primary mask-substrate stage using a linear motor for moving the substrate relative to the mask in one direction.
FIG. 10 illustrates an embodiment of the patterning system with an auxiliary stage mounted to the primary mask-substrate stage using a lead screw motor for moving the substrate relative to the mask in one direction.
FIG. 11 is a perspective view showing a set of platens mounted to the primary mask-substrate stage for feeding a continuous, flexible substrate onto the primary stage and moving the substrate relative to the mask in one direction.
FIG. 12 is a perspective view showing a set of edge rollers mounted to the primary mask-substrate stage for feeding a continuous, flexible substrate onto the primary stage and moving the substrate relative to the mask in one direction without contacting the substrate within the patterning area.
FIG. 13 illustrates an embodiment of a multi-element projection lens with zooming elements for symmetric and anamorphic magnification control in a small range around unit magnification.
FIG. 14 illustrates a mechanism for varying the magnification symmetrically in the embodiment shown in FIG. 13 by a linear translation of two weak spherical central elements.
FIG. 15 illustrates a mechanism for varying the magnification in one direction only in the embodiment shown in FIG. 13 by a linear translation of a weak cylindrical central element.
DETAILED DESCRIPTION OF THE EMBODIMENTS
FIG. 1 presents a simplified schematic of a portion of the new patterning system. A partial perspective is presented in FIG. 2. Substrate 16 is mounted in a substrate holder 17, which is rigidly held on a scanning stage 18. (In an embodiment of the invention for patterning roll-fed substrates, reference character 16 represents one panel-segment of a continuous substrate roll and is held in direct contact with the stage 18 without use of a substrate holder 17; this will be described in detail later.) On the stage 18 is also affixed a mask holder 21 in which is mounted a mask 20. The mask 20 contains the pattern to be produced on the substrate 16. The mask pattern is imaged by a projection lens 22 onto the substrate 16. The optical imaging path also contains a fold mirror 24 and an image reversing unit 26. The projection lens 22 is a refractive lens system, and the reversing unit 26 ensures that the orientation of the image on the substrate is the same as that of the pattern on the mask. The mask 20 is illuminated from below, through an opening 13 in the stage 18, by an illumination system 28. Illumination system 28 typically comprises a light source and additional optical units and components for beam shaping, uniformizing and turning; some of these components have been described in previous patents and are not shown here. The output of the illumination system 28 is delivered to the mask 20 after further processing by lens 30 and mirror 34, leading to uniform illumination of a hexagonal region on the mask.
The seamless scanning exposure mechanism has been described in detail in the previous patents cited above, and is summarized here with the illustration of FIG. 3. The single planar stage 18 (FIG. 1) causes the mask 20 and the substrate 16 to scan in unison along the x-axis (i.e., perpendicular to the plane of the paper) across their respective illuminated regions to traverse the length of one panel. The stage then moves along the y-axis by an effective scan width (shown as w, 52, in FIG. 3). Now the substrate and mask are again scanned along x as before, after which they are laterally moved along y, and the process is repeated until the entire panel is exposed. In FIG. 3, the hexagons 36 and 38 represent the illuminated regions on the substrate for scan 1 (50) and scan 2 (54). The y-movement after each x-scan is given by w=1.5 l h , where l h is the hexagon side-length. In scan 1, the region swept by the rectangular portion b-g-h-c of hexagon 36 is not overlapped by any portion of scan 2. However, the region swept by the triangular segment a-b-c of hexagon 36 in scan 1 is re-swept in scan 2 by the triangular segment d-e-f of hexagon 38. When the doses from these triangular segments are integrated, the cumulative exposure dose anywhere in the overlapping region is the same as in the non-overlapping regions, producing a seamless, uniform exposure over the whole substrate.
When the substrate is made of a flexible material and is fed from a roll, we have, instead of a discrete substrate 16 held in a holder 17 mounted on the stage 18, a panel-size segment 16 of the roll material 10, with the segment 16 being affixed to the stage by vacuum, and the illumination and scanning being as before. This is illustrated in FIG. 4, and has been previously described in the above-cited co-pending application by co-inventor Jain.
In another embodiment, the substrate 16 may comprise multiple segments, each corresponding to a mask with the same dimensions as one substrate segment.
The description above has illustrated how the patterning system concept using hexagonal seamless scanning enables the designer to deliver the desired resolution over very large substrate areas efficiently. Note that in the schematic illustrations of FIGS. 1, 2 and 4, since the mask and the substrate are held on a single scanning stage, the magnification of the projection subsystem must be precisely unity. If the magnification is not exactly 1:1, the image (produced on the substrate by the lens) of a given illuminated region on the mask will not overlap correctly with the image that will be produced when the illuminated region on the mask moves slightly as the stage scans. This is illustrated in FIGS. 5 and 6. Consider a segment 80 on the substrate which is imaged when the full illuminated region on the substrate is region 83. As the stage scans, let region 85 represent the illuminated region on the substrate a short time later. If the magnification of the projection system is precisely unity, the segment 80, when it is a part of region 85, will fall exactly at the same location as when it was a part of region 83. FIG. 6 shows what happens when there is a small departure from a magnification of 1:1. Here, 81 represents the location of the square segment (a slight magnification of 80) when it is a part of region 84 (a slight magnification of 83), and 82 represent the square segment when it is a part of region 86 (a slight magnification of 85). As depicted in FIG. 6, the two square segments fail to overlap exactly, resulting in blurring of the image and thus, loss of resolution. In a similar manner, when adjacent scans are partially overlapped according to FIG. 3, the same non-registration problem will occur in the overlap region between the scans, as illustrated in FIGS. 7 and 8.
Note that, as mentioned before, the situation in which an image magnification slightly different from unity exists, may not necessarily be from an error in the projection system but, rather, a desirable feature that will be attractive to have in order to accommodate any minute size variation the substrate may have undergone in a thermal or chemical processing step prior to the patterning exposure. Better still, the ideal system will provide independent control of the magnification values along the x-axis and the y-axis. Typically, the desired magnification adjustment is significantly smaller than 1%.
In order to provide correspondence between the size parameters of a mask feature and a substrate feature despite small discrepancies of mask-substrate congruence caused by previous processing, an embodiment of the invention provides that the substrate be equipped with means 41 and 43 to find and monitor registration marks 42 and 44 on substrate 16 as shown in FIG. 4. The control means 40 for the projection imaging system works with the means 41 and 43 to monitor the registration marks 42 and 44, to provide dynamic control of the optical magnification adjustment means and the auxiliary stage subsystem.
The objective of this invention is to make it possible for a scanning projection system employing a unitary stage to provide magnification adjustment control and, simultaneously, prevent the image non-registration shown in FIGS. 6 and 8. We now describe how the invention accomplishes this objective.
In the first embodiment, we describe how magnification control can be provided along the x-axis, i.e., the direction of the scan. Let the scanning velocity of the stage in the x-direction during exposure be ν x . Since the mask is held rigidly on the stage, the mask also moves with a velocity ν m =ν x . In the prior art cited above, the substrate is also held rigidly on the stage and therefore, its scanning velocity ν s is the same as that of the mask, i.e., ν s =ν x . Normally, the magnification, M, of the projection lens is assumed to be unity (M=1), and therefore, it is acceptable to have the scanning velocities of the substrate and the mask be equal, i.e., ν s =ν m .
However, if M departs from unity, as represented by M=1+δ, where δ<0.01, then the substrate and mask velocities being the same would cause image blurring as described in the paragraphs above and illustrated in FIGS. 5-8. The solution provided in the present invention is to enable a velocity differential between the mask and the substrate in the same proportion as the image magnification ratio. If the magnification is M=1+δ, we provide capability for the substrate holder to move on the stage by a small amount at a low velocity such that its effective velocity relative to the projection lens may be given by,
ν.sub.s =(1+δ)ν.sub.m.
In essence, we provide means for the substrate holder 17 to move with respect to the stage 18 at a velocity δν m , which adds to the stage velocity ν m , giving a net substrate velocity of (1+δ)ν m , which enables the substrate to compensate for the image shift caused by the magnification deviation of δ, and thus prevents the image blurring.
Mechanical Velocity and Scan Width Control
We now describe several ways of providing the above incremental velocity adjustment to the substrate. FIG. 9 depicts an embodiment in which the substrate holder 17 is situated in a slide 19 with a rail 11 in which the substrate holder is able to slide along the x-direction. The slide 19 is built into the stage 18. The drive for the slide 19 can be a linear motor, e.g., 15, or it can be some suitable mechanical means, as described later. Note that the total travel range for the substrate holder needed within the slide 19 is extremely small. For example, assuming a representative substrate size of 300×300 mm, a 1% magnification adjustment would require a maximum travel of 300×0.01=3 mm for the substrate holder. Similarly, the velocity at which the substrate holder needs to move within the slide is also very low. For example, assuming a typical mask scanning velocity of ν m =250 mm/sec, a deviation of 1% in the magnification would require that the substrate holder 17 move within the slide 19 at a speed of δν m =250×0.01=2.5 mm/sec. We remark that the direction of the movement of the substrate holder within the slide will alternate between the +x and -x directions as the scanning direction of the stage 18 alternates between the +x and -x directions. In practice, to determine δ, the substrate size is measured after each process step and compared to the mask size. Knowing δ, the slide motor 15 is then programmed to move the substrate holder 17 at a velocity of δν m .
An embodiment employing a different drive means is shown in FIG. 10. Here, the incremental motion of the substrate holder 17 in the slide 19 is provided by a lead screw 14 which is driven by a motor 12. We emphasize that in the embodiments of both FIGS. 9 and 10, the control signals that drive the motors 15 or 12 are provided by a central system control unit that ensures proper movements of all stages and operation of the illumination source.
In the descriptions of FIG. 9 and 10, we have realized magnification control along the x-axis by providing motion capability for the substrate. Alternatively, and in an identical fashion, the motion capability can be implemented for the mask instead of for the substrate, with similar effective result. In fact, making the mask movable in a slide may be somewhat preferable to making the substrate movable; this is so because the overall patterning system may include a high-speed, automated substrate loader which may require the substrate side of the stage 18 to frequently move in and out of the loader, which may make it desirable to make the substrate side of the stage light-weight and comprising few or no moving parts.
When the patterning system is designed for exposing flexible substrates, the adjustment of x-magnification is provided as shown in FIG. 11. Here, the flexible substrate 10 is held against the top surface of the stage 18 by platens 48 and 49. The platens are made with a suitable rubber-like surface that provide adequate friction so that by turning the platens, the substrate 10 can be moved along x. The platens are driven by motors 60 and 61. By providing appropriate control signals to these motors, the substrate can be moved at the required velocity in the x-direction to realize the desired net substrate velocity, and thereby the desired magnification. The platens shown in FIG. 11 make contact with the substrate along their entire length. As an alternative, when such contact is undesirable, the platens can be replaced with edge rollers (62-65), as shown in FIG. 12. At least one pair of the edge rollers in FIG. 12 are motor-driven, similar to platen motors 60 and 61.
If the substrate comprises multiple segments that are patterned using a single mask with the dimensions of one segment, the technique for providing magnification control is identical to that using a single substrate, except that the stage system must be capable of also moving the mask to a suitable location for patterning a selected segment of the substrate.
We also point out that whenever a magnification adjustment is made in the y-direction, the effective scan width w (FIG. 3) at the substrate must be adjusted accordingly so as to provide the proper partial overlap between adjacent scans as described earlier in this disclosure and as illustrated in FIG. 3. Because the effective scan width at the substrate will be different from the effective scan width at the mask when the magnification perpendicular to the scan direction deviates from unity, a relative movement between mask and substrate perpendicular to the scan direction must be performed as well. This is accomplished as described below.
To provide differential motion of the mask relative to the substrate both parallel to the scan direction (during scanning) and perpendicular to the scan direction (when stepping between scans) we use two auxiliary stages mounted to the primary stage to move either the mask or substrate. In the preferred embodiment, we use an auxiliary stage to give a relative motion between mask and substrate in one direction at the mask and an auxiliary stage to give a relative motion between mask and substrate in the orthogonal direction at the substrate. This method would be particularly useful if the relative motion in one direction is produced using platens or edge rollers for moving a roll-fed substrate. The complexity of the stage for adjusting the step width may be lower than the complexity of the auxiliary stage for adjusting the relative velocity during scanning since the movement is not made while imaging.
Optical Magnification Control
We next describe optical means to provide adjustment and control of the image magnification. One technique is to adjust the separation between certain elements or groups of elements in the projection lens assembly. By free adjustments of the spacings of the individual lens elements, the magnification of the projection lens assembly can be varied as desired in a small range around its nominal value of unity.
FIG. 13 illustrates an example of how the magnification control may be accomplished. A projection lens assembly 22 is made up several lens elements; the embodiment shown in FIG. 13 has six elements 71, 72, 74, 76, 78, and 79 with spherical, rotationally symmetric surfaces, and two elements 73 and 77 with cylindrical surfaces. The aperture stop 75 is located at the center of the lens, and the lens is roughly symmetric about the aperture stop 75. In FIG. 13, the local x- and y-axes for the projection lens correspond to the x- and y-axes of the illuminated region on the substrate 16 shown in FIG. 1 such that a change in the x- and y-magnification of the projection lens will produce a corresponding change in x- and y-magnification of the image at the substrate. In this example, the lens has been designed nominally for imaging at unit magnification with resolution of 10 μm using a 308 nm xenon chloride excimer laser source. Other parameters include a 50 mm field of view, a numerical aperture of 0.0154, and a total track length from object to image plane of roughly one meter.
Most of the power and aberration correction is produced by the outer lens elements 71, 72, 78, and 79, which are symmetric about the aperture stop 75. To vary the magnification symmetrically, two central lens elements 74 and 76 may be moved relative to the rest of the lens assembly. The magnification adjustment will be equal in the x- and y-directions since the effect of adjusting the positions of lens elements 74 and 76 is axially symmetrical around the optical axis of the lens assembly. In this embodiment, these elements are weakly positive (long positive focal lengths) and may be moved in unison to provide a variation of magnification (identical in x- and y-directions) over the range of -0.990 to -1.010 (±1%) without significant degradation of imagery (negative magnification indicates that the lens inverts the image). The magnification change is linear over this range as a function of the displacement of the components along the optical axis.
Since lens elements 74 and 76 are moved in unison over the entire range of magnification, they may be mounted into a common fixture. In FIG. 13, the lens elements 74 and 76 and the aperture stop 75 are mounted in a common barrel 93 which may be moved by a single drive motor 91 over Zoom Range A. Since Zoom Range A is small, it may be acceptable to move the aperture stop along with lens elements 74 and 76. Alternatively, barrel 93 may be designed with slots to allow the aperture stop 75 to be held at a fixed position with respect to the main lens barrel 22 by spokes that will not inhibit the motion of the inner barrel 93.
FIG. 14 shows the variation in the axial position (Zoom Range A) of elements 74 and 76 for a range of magnification of +1%. At unit magnification, these elements are symmetric about the aperture stop.
To vary the magnification in the x-direction only (or alternatively, in the y-direction), two cylindrical elements 73 and 77 are used, as shown in FIG. 13, and dement 77 is moved relative to the rest of the lens assembly by drive motor 92. Element 73 is cylindrical such that it has no curvature in the y-direction and is very weakly negative in the x-direction. Inner element 77 is cylindrical such that it has no curvature in the y-direction and is very weakly positive in the x-direction. The focal length of dement 73 is approximately equal and opposite in sign to that of dement 77. Here, a magnification variation over the range of ±0.5% may be achieved. The magnification varies linearly as a function of the axial displacement of dement 77. FIG. 15 shows the movements of dement 77 (over Zoom Range B) that give a magnification variation of ±0.5%.
The symmetric magnification variation resulting from movement of elements 74 and 76 may be added to the variation of magnification in the x-direction produced by moving element 77. Thus, this example will provide anamorphic magnification variation with a range of magnification variation in the y-direction of up to ±1% and additional variation in the x-direction of up to ±0.5%, without degrading the performance of the lens.
The lens in this example was designed to show the feasibility of providing anamorphic magnification variation with a high-resolution lithographic lens. For a given application, the specifications of the lens, including resolution, numerical aperture, optimal wavelength, total track, and required range of magnification would depend upon the requirements of the particular application.
There are many possible arrangements of the projection lens that would allow for the required anamorphic magnification variation. The goal of the optimum design is to minimize the number of elements and complexity of the required motion control. Other variations of the above embodiment are possible. For example, the cylindrical elements for magnification control in one direction only may be placed inside the elements moved for symmetric magnification control with similar results. The same results may also be obtained by moving element 73 rather than 77 for magnification control in only one direction. Motion of both elements 73 and 77 relative to the rest of the lens may be used to provide the magnification control, which may be beneficial if the required magnification range is very large or the range of travel needs to be reduced. Motion of both cylindrical elements will generally be more complex than motion of one element only.
Another possible design choice would have two cylindrical elements for magnification control in the x-direction and two cylindrical elements for magnification control in the y-direction, which would allow for completely independent control of magnification in the two dimensions.
The example illustrated in FIGS. 13-15 keeps the overall length of the projection lens and the object and image distances constant as some of the individual lens elements are zoomed. If keeping the overall length of the projection lens is not a constraint, then motion of the outer elements relative to the center of the lens may also be used; this may have the benefit of reducing the number of elements required or increasing the range of magnification control.
If the specific design requires that the zooming lens elements be moved independently, separate drive motors for each lens element may be used. Another common method is to support the moving lens elements in cells on guide rods; the cells are then driven by balls or cam follower pins running in slots in a cylindrical cam.
Dynamic control of the optical magnification adjustment means is provided by the control means 40 for the projection imaging system. When the substrate 16 is equipped with registration marks 42 and 44, the control means 40 works with monitoring means 41 and 43 to monitor the registration marks so as to provide corresponding size parameters of a mask feature and substrate feature, even when there are small discrepancies of mask-substrate congruence caused by previous processing.
With the combination of mechanical control of the scan velocity and step width (FIGS. 9-12) and optical control of the image magnification (FIGS. 13-15), the required variations in magnification can be provided while allowing the mask and substrate to be scanned together on a common stage. Furthermore, any required values of magnification adjustment can be provided independently along the x- and y-directions to compensate for different scale changes of the substrate as a result of various process steps. | In numerous applications of large-area patterning systems, the preferred image magnification is unity. However, in some applications, the size of the substrate may change slightly due to various thermal and/or chemical processing steps. To compensate for scale changes of the substrate, the magnification of the imaging system must vary slightly from unit magnification (typically by a fraction of a percentage) so that a layer already patterned on the substrate will have, after processing, proper image registration with the subsequent layer.
This disclosure describes a lithography system for exposing large substrates at high imaging resolution and high exposure throughput, and specifically relates to a scan-and-repeat patterning system that employs a unitary mask-substrate stage and enables projection imaging of a substrate with capability to control the image magnification to compensate for changes of substrate dimensions occurring as a result of previous process steps.
A combination of optical and mechanical compensation is used to provide the necessary magnification control, including anamorphic magnification variation in which the fine adjustment is of different magnitudes in x and y dimensions. The optical control is provided by a projection lens with anamorphic magnification adjustment capability. The mechanical compensation is performed by providing a differential relative velocity between the mask and substrate during scanning. | 6 |
This application is a continuation of International Patent Application No. PCT/US99/02566, filed May 2, 1999, which claims priority to U.S. Provisional Application No. 60/073,749, filed Feb. 5, 1998, which are hereby incorporated herein by reference.
FIELD OF INVENTION
The present device relates to the field of medical devices for fluid sampling. More specifically, the present invention relates to such medical devices having a retractable needle, so that the device is rendered safe after use. In particular, the present invention relates to a device for drawing blood from a patient, wherein after use the needle retracts so that the contaminated needle is enclosed thereby preventing inadvertent contact with the contaminated needle.
BACKGROUND
The present invention relates to a type of medical device that is used to take a sample of arterial blood. An arterial blood collection is done commonly in emergency room settings, as well as hospitals to test for various conditions, such as blood oxygen levels and pH. The standard devices currently used are coated with heparin to prevent blood clotting and the fit between the plunger piston and the barrel is loose enough to allow the arterial blood pressure to move the piston as the device fills with arterial blood. These requirements complicate the reaction of the needle.
SUMMARY OF THE INVENTION
In light of the foregoing, the present invention provides an apparatus and method for collecting fluid samples from a patient. The device comprises a housing, a plunger slidably displaceable within the housing and a needle having a sharpened tip for piercing a patient. The needle is operable to pierce the skin of a patient. Fluid from the patient collects in a fluid chamber within the housing. After the sample is collected, the needle is retracted into the housing so that the sharpened tip is enclosed. After the needle is retracted a pair of seals prevent the sample from leaking from the fluid chamber. In addition, the seals preferably operate to prevent air from entering the fluid chamber after the needle is retracted. The fluid can then be expelled from the fluid chamber by displacing the plunger within the housing.
DESCRIPTION OF THE DRAWINGS
The foregoing summary as well as the following detailed description of the preferred embodiment can be best understood when read in connection with the following drawings in which:
FIG. 1 is a top view of a fluid sampling medical device having a retractable needle;
FIG. 2 is a side view of the fluid sampling medical device shown in FIG. 1 ;
FIG. 3 a is a side view of the device shown in FIG. 1 , illustrating the device prior to use;
FIG. 3 b is a side view of the device shown in FIG. 3 a , illustrating the device after a quantity of fluid has been withdrawn;
FIG. 3 c is a side view of the device shown in FIG. 3 a , illustrating the device with the needle in a retracted position;
FIG. 3 d is a side view of the device shown in FIG. 3 a , illustrating the device after the fluid sample has been expelled;
FIG. 4 is a side view of a second embodiment of a fluid sampling medical device having a retractable needle;
FIG. 5 a is a side view of the device shown in FIG. 4 , illustrating the device prior to use;
FIG. 5 b is a side view of the device shown in FIG. 5 a , illustrating the device after a quantity of fluid has been withdrawn;
FIG. 5 c is a side view of the device shown in FIG. 5 a , illustrating the device with the needle in a retracted position;
FIG. 5 d is a side view of the device shown in FIG. 5 a , illustrating the device after the fluid sample has been expelled;
FIG. 6 is a side view of third embodiment of a fluid sampling medical device having a retractable needle;
FIG. 7 a is a side view of the device shown in FIG. 6 , illustrating the device prior to use;
FIG. 7 b is a side view of the device shown in FIG. 7 a , illustrating the device after a quantity of fluid has been withdrawn;
FIG. 7 c is a side view of the device shown in FIG. 7 a , illustrating the device with the piston separated from the plunger;
FIG. 7 d is a side view of the device shown in FIG. 7 a , illustrating the device with the needle in a retracted position;
FIG. 8 is a side view a fourth embodiment of a fluid sampling medical device having a retractable needle;
FIG. 9 is an enlarged fragmentary sectional view of the device shown in FIG. 8 ;
FIG. 10 is a cross-sectional view of the device shown in FIG. 9 , taken along the line 10 — 10 ;
FIG. 11 is a side view of the device shown in FIG. 8 , illustrating the device with the needle in a retracted position;
FIG. 12 a is an exploded side view of a combination syringe and removable needle assembly;
FIG. 12 b is a side view of the device shown in FIG. 12 a , illustrating the needle assembly attached to the syringe;
FIG. 12 c is a side view of the device shown in FIG. 12 a , illustrating the needle in a retracted position;
FIG. 13 a is a side view of a second embodiment of removable needle assembly; and
FIG. 13 b is a side view of the needle assembly shown in FIG. 13 a , illustrating the needle in a retracted position.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to the drawings and to FIGS. 1–3 d specifically, a fluid sampling device is designated generally 10 . The device 10 comprises a barrel 20 and a needle 40 projecting forwardly from the forward end of the barrel. A plunger 30 is slidably displaceable within the barrel 20 . Fluid is sampled through the needle. For instance, the device may be used to withdraw a quantity of fluid from a patient. The needle 40 pierces the skin of a patient, and blood from the patient flows into the barrel 20 . After a sufficient amount of blood has been withdrawn, the needle 40 is retracted into the barrel 20 so that the needle is enclosed, preventing inadvertent contact with the contaminated sharpened point of the needle.
Referring now to FIGS. 1 and 2 , the barrel 20 is an elongated generally cylindrical hollow housing. The forward end of the barrel 20 forms a reduced diameter nose piece 22 . The nose piece 22 is generally closed, having an aperture for receiving the needle 40 .
The plunger 30 has a hollow forward stem 31 . An elastomeric piston 32 is attached to the forward end of the plunger stem 31 . The piston 32 forms a fluid-tight seal with the interior wall of the barrel 20 . The stem is integrally formed with the rearward portion of the plunger, which is an elongated hollow cylindrical portion, which forms a needle chamber 34 for receiving the needle after the needle is retracted. The rearward end of the needle chamber is closed to prevent the needle from being displaced rearwardly of the needle chamber. An actuator 36 is formed at the forward end of the needle chamber 34 . The actuator is generally wedge-shpaed and is formed to matingly cooperate with a needle retainer 50 that releasably retains the needle.
The needle 40 includes a side port 42 formed in the side wall of the needle. In addition, the rearward end of the needle is plugged. The needle is disposed so that the side port 42 is located forward of the piston. A variable volume is formed in the barrel between the piston 32 and the forward end of the barrel 20 . Accordingly, fluid flowing through the needle is discharged through the side port 42 into the fluid chamber between the piston 32 and the nose 22 .
The needle 40 is operable between a projecting position in which the sharpened tip of the needle projects forwardly from the nose 22 of the barrel 20 , and a retracted position in which the needle is enclosed within the barrel. A spring 60 circumscribes the needle 40 , biasing the needle rearwardly toward the retracted position. The needle retainer 50 releasably retains the needle 40 in the projecting position against the bias of the spring 60 . When the actuator 36 engages the needle retainer 50 , the needle retainer releases the needle 40 , allowing the spring to propel the needle rearwardly into the needle chamber 34 .
The needle retainer 50 is rigidly connected to the barrel 20 so that the needle retainer is fixed axially relative to the barrel. The interior wall of the barrel 20 includes a recess that forms a seat 25 for receiving the needle retainer 50 . As shown in FIG. 1 , the needle retainer 50 comprises a pair of connecting tabs 58 that form a snap fit or friction fit with the seat 25 in the wall of the barrel. The connecting tabs 58 project through a pair of slots 38 in the side walls of the plunger 30 . The slots allow the plunger to be displaced axially relative to the needle retainer.
The needle retainer 50 includes at least one finger or latch 52 for releasably retaining the needle. In the present instance, the fingers 52 are bonded to the needle by UV curable epoxy. Alternatively, a block can be attached to the needle and the finger can abut the block to retain the needle against rearward axial displacement.
The forward end of the fingers form a tapered actuation surface 56 that cooperates with the tapered actuator 36 on the plunger. When the plunger is displaced rearwardly, the actuator 36 engages the tapered actuation surface 56 of the needle retainer, wedging the fingers apart. In this way, the fingers are displaced radially outwardly out of engagement with the needle. The spring then propels the needle rearwardly into the needle chamber 34 .
The needle retainer 50 further includes a spring housing 54 projecting forwardly from the fingers 52 . The forward end of the spring housing 54 form a bearing surface against which the forward end of the spring 60 bears. The rearward end of the spring is bonded to the needle. Alternatively, if a block is attached to the needle, the rearward end of the spring may bear against the block.
As shown in FIGS. 1 and 2 , in the projecting position, the forward end of the needle projects from the forward end of the barrel 20 . The needle also projects through the piston 32 and into the needle retainer 50 . The piston 32 includes a pierceable septum that forms a fluid-tight seal with the exterior surface of the needle to prevent fluid from leaking from the barrel into the plunger 30 . In addition, in the projecting position, the needle pierces a nose seal 24 disposed within the nose 22 of the barrel. The nose seal forms a fluid-tight seal with the exterior surface of the needle to prevent fluid from leaking from the barrel through the nose 22 .
The device can be designed to operate in two different manners. In the first manner, the plunger is withdrawn to form a fluid chamber of a particular volume. The needle is then inserted into a patient and blood flows through the needle and into the barrel, filling the fluid chamber. When designed to be used in this manner, a hydrophobic vent is included to prevent the device from becoming airlocked, which would impede the flow of blood into the fluid chamber. The vent is air permeable, but is not permeable to blood The vent allows air from the fluid chamber to be discharged from the fluid chamber as the blood enters the fluid chamber, but prevents blood from leaking from the fluid chamber.
Alternatively, the device 10 can be configured to operate so that the blood pressure displaces the plunger rearwardly as blood enters the fluid chamber. During such use, the plunger is displaced forwardly so that the piston is disposed at the forward end of the barrel, engaging the forward wall of the barrel. The needle is then inserted into the patient and blood flows into the barrel, displacing the piston 32 rearwardly as blood enters the barrel. When designed to be used in such a manner, the device does not need a vent for venting air from the fluid chamber. In addition, the piston or the barrel wall is lubricated to reduce the friction between the piston and the barrel to facilitate displacing the plunger.
Referring now to FIGS. 3 a – 3 d , the device operates as follows. In FIG. 3 a , the device is shown prior to use. The needle 40 is inserted into a patient's blood vessel, and blood flows into the fluid chamber in the barrel as shown in FIG. 3 b . Referring to FIG. 3 c , the plunger is then displaced axially rearwardly so that the actuator 36 engages the needle retainer 50 displacing the fingers 52 radially outwardly to release the needle. The spring 60 then propels the needle rearwardly into the needle chamber so that the needle is enclosed with in the barrel. After the needle retracts, the septum of the piston that was pierced by the needle reseals to prevent blood from leaking into the plunger. In addition, the nose seal 24 reseals to prevent blood from leaking through the nose 22 . In this way, the sample is sealed within the fluid chamber against contact with the air. Referring now to FIG. 3 d , after the needle is retracted, the sample can discharged from the syringe so that the sample can be tested. The sample is discharged by displacing the plunger forwardly. Displacing the piston forwardly creates sufficient fluid pressure to expel the fluid through the hole in the nose seal membrane that was formed by the needle.
Referring now to FIGS. 4–5 d , a second embodiment 110 of a fluid sampling device is shown. The device 110 includes a barrel 120 and a retractable needle 140 projecting forwardly from the barrel. A plunger 130 is slidably displaceable within the barrel. After a fluid sample is collected in the device, the needle is retracted into the barrel so that the needle is enclosed to prevent inadvertent contact with the contaminated needle. After the needle is retracted, the fluid is sealed within a fluid chamber in the barrel. The fluid sample can then be discharged so that the sample can be tested.
The plunger 130 includes a tapered hollow stem 132 . An elastomeric piston 132 is removably attached to the forward end of the stem. The piston forms a fluid-tight seal with the interior of the barrel. Preferably, a hydrophobic plug 136 extends through the piston, providing a vent for gases in the fluid chamber between the piston and the forward end of the barrel. An inwardly projecting annular flange or stop ring 125 limits the rearward axial displacement of the piston. After the piston engages the ring stop 125 , continued rearward displacement of the plunger detaches the piston from the plunger.
The plunger stem projects forwardly from the rearward portion of the plunger, which is an elongated generally cylindrical hollow portion, forming a needle chamber 134 . The stem 132 is also hollow, forming a forward chamber 137 for receiving the rearward end of the needle when the needle 140 is disposed in the retracted position. The forward end of the forward chamber is smaller in diameter than a block 146 attached to the rearward end of the needle. In this way, upon rearward displacement of the plunger, the interior wall of the forward chamber 137 engages the block 146 on the needle urging the needle rearward. This in turn displaces the needle out of engagement with a needle retainer 150 so that continued rearward displacement of the plunger retracts the needle rearwardly.
The forward end of the barrel 120 forms a reduced diameter nose 122 . The needle projects forwardly from the nose 122 in the projecting position. In this position, the needle passes through an opening in the forward end of the piston. The forward opening in the piston is smaller in diameter than the needle, so that the piston forms a fluid-tight seal around the exterior of the needle.
A needle retainer 150 releasably retains the needle in the projecting position. In the present instance, the needle retainer comprises a pair of receptacles 152 that cooperate with and engage a spherical detent 144 fixed to the needle.
The device 120 operates as follows. Referring to FIG. 5 a , the device 110 is shown prior to use. The plunger 130 is displaced rearwardly to provide a fluid chamber for receiving the fluid sample. The needle is then inserted into the artery of the patient. Blood flows through the needle into the fluid chamber through a side port in the needle to collect the sample, as shown in FIG. 5 b . Referring to FIG. 5 c , after the sample is collected, the plunger is displaced rearwardly to detach the piston from the plunger. The plunger is further displaced rearwardly to retract the needle into the barrel. Referring to FIG. 5 d , the sample can then be expelled by driving the plunger forward to re-engage the piston and then drive the piston forwardly.
Referring now to FIGS. 6–7 d , a third embodiment of a fluid sampling medical device 210 is illustrated. The device includes a barrel 220 and a retractable needle 240 projecting from the forward end of the barrel. A plunger 230 is slidably displaceable within the barrel. After a fluid sample is collected from the patient, the needle retracts into the barrel to enclose the contaminated needle.
The barrel is generally cylindrical and hollow. The plunger 230 includes an elastomeric piston 234 that forms a fluid-tight seal with the interior wall of the barrel. The plunger 230 is hollow, having a forward chamber 239 housing the spring before the needle is retracted, and a rearward needle chamber 237 for receiving the needle after the needle is retracted.
A spring 260 circumscribing the needle biases the needle rearwardly towards the retracted position. The spring is disposed about the needle 240 between a fixed spring block 228 and a needle block 244 connected to the rearward end of the needle. The spring block 228 is fixedly attached to the barrel 220 . Accordingly, slots 233 are formed in the side of the plunger 230 to provide clearance for the spring block 228 when the plunger is displaced within the barrel.
A needle retainer 250 releasably retains the needle in the projecting position against the bias of the spring 260 . In the present instance, the needle retainer is epoxy that bonds the needle to the nose 222 .
Referring to FIGS. 7 a – 7 d , the device operates as follows. In FIG. 7 a , the device is illustrated prior to use. The plunger 230 is withdrawn to provide a fluid chamber between the piston 234 and a resealable seal 224 that is disposed in the nose of the barrel and provides a fluid-tight seal with the exterior of the needle 240 . Referring to FIG. 7 b , the needle 240 is inserted into a patient's artery, and blood flows through a side port 242 in the needle 240 and into the fluid chamber. Once the sample is collected the needle is withdrawn from the patient. Referring to FIG. 7 c , the plunger 230 is then displaced rearwardly. The rearward displacement brings the piston 234 into engagement with an annular flange projecting inwardly from the interior wall of the barrel. Continued rearward displacement of the plunger detaches the piston 234 from the stem 232 of the plunger. In addition, the rearward displacement brings an annular flange 238 into engagement with the needle block 244 . Referring to FIG. 7 d , further rearward displacement of the plunger breaks the bond between the nose 222 and the needle, releasing the needle from the needle retainer 250 . The spring then propels the needle rearwardly into the needle chamber. The nose seal 224 reseals to prevent the sample from leaking through the nose 222 of the barrel. In addition, the forward end of the piston 234 reseals to prevent the sample from leaking into the plunger. In this way, the nose seal 224 and the piston 234 seal the sample within the fluid chamber to prevent the sample from contacting the air. After the needle is retracted, the sample can be expelled from the barrel into equipment for testing the sample by driving the plunger forwardly.
Referring now to FIGS. 8–11 , a fourth embodiment of a fluid sampling device 310 is shown. The device includes a barrel 320 , a retractable needle 340 and a plunger 330 slidably displaceable within the barrel. This third embodiment allows the operator to actuate retraction of the needle regardless of the axial position of the plunger.
The barrel 320 is generally cylindrical. The forward end of the barrel is generally closed, forming a reduced diameter opening. A female Luer-type fitting 322 projects from the forward end of the barrel 320 . An elastomeric seal threadedly engages the Luer fitting 322 . The seal 324 includes a pierceable membrane through which the needle 340 projects. The membrane forms a fluid-tight seal with the exterior of the needle 340 .
The plunger 330 includes a piston 332 that forms a fluid-tight seal with the interior wall of the barrel. In addition, the piston 332 includes a pierceable membrane through which the needle projects. The piston membrane forms a fluid-tight seal with the exterior of the needle. In addition, the piston includes a hydrophobic plug 336 that allows gas to vent from the fluid chamber between the piston and the nose seal 324 . Referring to FIGS. 10 and 11 , the plunger 330 is a generally U-shaped channel, having a needle chamber 334 for receiving the retracted needle 340 . A longitudinal, axially elongated rib 335 projects upwardly into the needle chamber 334 .
Referring now to FIGS. 8–10 , a manually operable needle retainer 350 releasably retains the needle in the projecting position against the bias of the spring 360 biasing the needle rearwardly toward the retracted position. The needle retainer 350 comprises an actuating lever 354 and a latch that engages a block 344 attached to the needle. As shown in FIG. 9 , the latch 354 engages the needle block 344 to releasably retain the needle. By operating the actuator lever 352 , the latch 357 pivots radially outwardly out of engagement with the needle block 344 . The spring 360 then propels the needle rearwardly toward the retracted position.
The latch 357 is biased into engagement with the needle block 344 . In the present instance, a spring finger 359 biases the latch into engagement with the needle block. The spring finger 359 is integral with the latch and projects rearwardly from the latch. The spring finger 359 resiliently flexes and engages the interior wall of the barrel 320 . When the actuating lever 354 is operated, the latch displaces radially outwardly, thereby resiliently deforming the spring finger 359 .
Referring to FIG. 10 , the needle retainer 350 is attached to the barrel 320 by mounting brackets 352 . The mounting brackets 352 engage a slot 326 formed in the top of the barrel. The mounting brackets 352 fix the needle retainer relative to the plunger 330 . A transverse spring block 351 is connected to the needle retainer assembly. The spring block forms a forward bearing surface for the spring 360 . The actuating lever 354 is attached to the spring block 351 by a flexible web or living hinge 355 . The web 355 forms a pivot point for the actuating lever 354 .
The device operates as follows. The plunger 330 is withdrawn to provide a fluid chamber for receiving a blood sample from a patient. The needle 340 is inserted into a patient's artery. Blood flow through a side port 342 in the needle and into the fluid chamber. Once a sufficient amount of blood is withdrawn, the needle is withdrawn from the patient. The actuating lever is depressed to pivot the latch 357 thereby releasing the needle from the needle retainer 350 . The spring 360 then propels the needle rearwardly into the needle chamber. After the needle is retracted, the nose seal 324 reseals to prevent from blood from leaking from the fluid chamber. The fluid sample can then be expelled from the device into separate device to test the sample. The sample is expelled by driving the plunger forwardly within the barrel.
Referring now to FIGS. 12 a – 12 c , a device for collecting a fluid sample such as blood is designated generally 410 . The device 410 comprises a syringe 420 and a removably connectable needle assembly 430 . The needle assembly 430 comprises a retractable insertion needle 460 for piercing a patient's skin. When the needle assembly 430 is connected to the syringe 420 , the insertion needle 460 is in fluid communication with the interior of the syringe. After the fluid sample is collected in the syringe 420 , the insertion needle 460 can be retracted into the housing of the needle assembly 430 to prevent inadvertent contact with the contaminated insertion needle. The needle assembly 430 can also be removed from the syringe 420 after the fluid sample is collected. The fluid sample can then be transferred to where the sample is to be tested. The sample can then be expelled from the syringe 420 and tested.
The syringe 420 is similar to a typical syringe, having a barrel 422 , a plunger 424 with a piston 425 slidably displaceable within the barrel and a Luer-type fitting 428 on the nose of the barrel. The piston 425 forms a fluid-tight seal with the interior wall of the barrel 422 , and driving the plunger forward expels fluid from the syringe 420 .
The needle assembly 430 is adapted to connect to the Luer fitting 428 of the syringe so that the needle assembly can be utilized with standard syringes that are already in widespread use throughout the medical field. Accordingly, the housing 440 of the needle assembly 430 includes an opening at the rearward end, forming a socket 442 for engaging the Luer fitting 428 of the syringe. A seal 445 having a pierceable resealable membrane is disposed within the socket 442 . The seal 445 is externally threaded having threads that cooperate with the Luer fitting 428 .
The needle assembly 430 comprises two needles a forward insertion needle 460 that projects forwardly from the front end of the housing 440 , and a fixed needle 450 disposed within the housing 440 . The fixed needle 450 projects into the socket 442 , piercing the Luer seal 445 . The fixed needle 450 is attached to a fixed needle tube 452 that is fixedly attached to the housing 440 . The rearward end of the fixed needle tube is generally closed, having a reduced diameter through which the fixed needle 450 projects. The fixed needle is fixedly connected to the fixed needle tube 452 to form a fluid-tight connection between the exterior surface of the fixed needle and the generally closed rearward end of the fixed needle tube.
The insertion needle 460 is fixedly connected to a telescoping needle tube 462 that telescopingly engages the interior of the fixed needle tube 452 . A needle seal 456 disposed within the forward end of the fixed needle tube 452 provides a fluid-tight seal between the fixed needle tube and the telescoping needle tube. The insertion needle projects forwardly from the forward end of the telescoping needle tube 462 . An annular flange 464 projects outwardly from the telescoping needle tube 462 . A spring 480 circumscribing the telescoping needle tube 462 is disposed between the flange 464 and the interior of the forward end of the housing. The spring 480 bears against the flange 464 biasing the telescoping needle tube 462 and the attached insertion needle 460 rearwardly.
A needle retainer 470 releasably retains the insertion needle 460 against the bias of the spring 480 . The needle retainer 470 comprises an actuator button 472 and a latch 474 . The latch 474 has an aperture through which the telescoping needle tube 462 projects. In the latched position, the latch 474 is disposed so that the rim of the aperture engages the flange 464 to retain the telescoping needle tube against the bias of the spring. Depressing the actuator button 472 displaces the latch 474 downwardly so that the latch aperture is aligned with the annular flange 464 . The spring 480 then propels the telescoping needle tube rearwardly into the fixed needle tube, so that the insertion needle is enclosed within the housing 440 .
Accordingly, the device 410 operates as follows. The plunger 424 is disposed so that the piston 425 is located at the forward end of the syringe barrel 422 . The needle assembly 430 is connected to the front end of the syringe 420 . The rear fixed needle 450 projects through the Luer seal 445 and into the barrel. The insertion needle 460 is then inserted into a patient's artery and blood flows from the patient into the interior of the syringe. The pressure of the blood flow drives the piston and plunger 424 rearwardly as the blood enters the syringe 420 . After a sufficient amount of blood is collected, the insertion needle is withdrawn from the patient. The actuator button 472 is depressed to actuate retraction of the insertion needle. The insertion needle then retracts into the housing. The needle assembly 430 is then detached from the syringe 420 . The Luer seal 445 remains on the Luer-fitting 428 of the syringe, sealing the forward end of the syringe to prevent fluid from leaking out of the nose of the syringe 420 . The piston 425 forms a fluid-tight seal with the barrel to prevent fluid from leaking out of the rearward end of the syringe. The sealed fluid sample can then be transported to an area for testing the sample and then expelled from the syringe by driving the plunger forwardly within the barrel.
Referring now to FIGS. 13 a and 13 b a second embodiment of a needle assembly that is operable in connection with a syringe is designated generally 510 . The needle assembly includes a housing 520 and a retractable needle 540 projecting forwardly from the housing. The rearward end of the housing forms a socket 522 for connecting the needle assembly to a syringe similar to the manner described above in connection with the device designated 410 and illustrated in FIGS. 12 a – 12 c . However, in the present instance, the socket 522 is configured as a female tapered Luer-type fitting to cooperate with a male Luer-type fitting on a syringe.
The needle assembly 510 includes a generally cylindrical nose piece 530 attached to the forward end of the housing 520 . A nose seal 532 forms a fluid-tight seal with the exterior of the needle 540 . A generally cylindrical needle tube 545 is disposed within the housing 520 and projects into the rearward end of the nose piece 545 . The forward end wall of the socket 522 has a reduced diameter opening so that the needle tube 545 is in fluid communication with the socket. An annular detent 542 projects inwardly into the needle tube adjacent the forward end of the needle tube 545 . An elastomeric valve 550 seals the forward end of the needle tube 545 . The valve 550 has an external circumferential groove 552 . The annular detent 542 engages the circumferential groove to releasably retain the valve 550 .
The rearward end of the needle 540 projects into the valve 550 . The forward end of the needle 540 projects forwardly from the nose piece. A spring 560 attached to the needle biases the spring rearwardly to a retracted position within the housing 520 . A needle retainer 570 releasably retains the needle in the projecting position against the bias of the spring.
The needle retainer 570 is configured similarly to the needle retainer described above in connection with the previous device 410 . The retainer 570 comprises a button actuator 572 and a latch 574 . The latch has an aperture. In the latched position, the rim of the latch aperture engages the end of the spring 560 . When the actuator button 572 is depressed, the latch is displaced downwardly, aligning the latch aperture with the spring, thereby allowing the spring to propel the needle rearwardly as shown in FIG. 13 b.
Accordingly, the device operates as follows. The needle assembly 510 is attached to a syringe. The needle is then inserted into a patient's artery. Blood flows through the needle 540 , and through the valve 550 into the needle tube 545 . From the needle tube the blood flows into the syringe, where the sample collects. After a sufficient amount of blood is removed, the needle 540 is removed from the patient. The actuator button 572 is depressed to release the needle 540 . The spring 560 propels the needle rearwardly. The needle is driven further within the valve, sealing the rearward end of the needle. In addition, the spring biases the valve against the opening into the socket to seal the socket opening. The needle assembly thereby operates as a seal, sealing the forward end of the syringe. The needle assembly can be detached if desired. The syringe can then be sealed with a cap and transported to an area where the sample is to be tested. The sample can then be expelled from the syringe by driving the plunger forward.
While particular embodiments of the invention have been illustrated and described above, it is not intended to limit the invention to such disclosure. It will be recognized that changes and modifications may be made within the scope of the following claims. | A method for withdrawing a fluid sample from a patient is disclosed comprising the steps of: a) providing a sampling device ( 10 ) having a housing ( 20 ) and a needle ( 40 ) having a sharpened tip for piercing the skin of the patient; b) withdrawing fluid from the patient into the housing; c) retracting the needle so that the sharpened tip of the needle is enclosed within the housing; and d) expelling the fluid from the housing after the needle is retracted. | 0 |
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims the benefit of U.S. Provisional Application No. 60/190,803 filed Mar. 21, 2000.
FIELD OF THE INVENTION
[0002] This invention relates to wireless communication networks and more specifically to CDMA wireless systems subject to co-channel interference.
BACKGROUND OF THE INVENTION
[0003] Code Division Multiple Access (CDMA) networks are widely deployed throughout the world. The current implementations of CDMA typically follow the IS-95 industry standards and are referred to as IS-95 wireless systems. With the advent of enhancements to CDMA technology such as third generation CDMA, CDMA2000 and W-CDMA, the deployment of CDMA is expected to increase dramatically.
[0004] A typical CDMA system 100 is shown in FIG. 1 . It is divided into a plurality of cells 121 . Each cell contains a fixed base station 103 . Each base station 103 is connected to a centralized switch or mobile switching center 109 that provides switching capabilities and acts as a gateway to wired networks such as the public switched telephone network (PSTN), the Internet, and other public and private data communications networks. As is known, the base station 103 includes a transmitter 105 and a receiver 107 for communicating with the mobile customers or users.
[0005] On the customer side, users connect to the wireless network through wireless mobile nodes 101 that can act as transmitters and receivers. The mobile nodes 101 communicate with the base stations 103 over wireless communications links. The link from a base station transmitter 105 to a mobile node receiver is the forward link 115 (or downlink). The link from the mobile node transmitter to a base station receiver 107 is referred to as the reverse link 113 (or uplink).
[0006] One advantage of CDMA over other wireless access systems is that all users share the same spectrum at the same time. However, the fact that multiple users occupy the same bandwidth limits performance and capacity. Because the conventional matched filter receiver 107 does an imperfect job of removing signals from these users, each user in a CDMA system degrades the performance of every other user; this effect is called multiple access interference or MAI. An increase in interference between users can lower the ability of a wireless provider to reuse frequencies, resulting in a reduction of system capacity. Because of the tremendous demand for wireless voice and data services and increased competition between service providers, CDMA network providers cannot afford such a reduction in system capacity. Therefore, wireless providers are continually striving to maximize system capacity, which in turn, requires limiting interference.
[0007] In CDMA wireless systems, power control is used to control the level of MAI at the base station. By adjusting every user's power so that all user transmissions arrive at the base station at approximately the same level, the base station receiver for each user sees the same amount of MAI, and the link quality is roughly the same for each user. If power control was not implemented, then a single user close to the base station could prevent the conventional CDMA receiver for other users from receiving a usable signal, resulting in the so-called near-far problem.
[0008] Power control works reasonably well for currently deployed CDMA wireless systems although limitations in the speed of power control are a constant engineering concern and limit capacity and link quality. However, there are frequently situations where it is desirable to deploy auxiliary receivers that are not the target of mobile station power control. Auxiliary receivers can be used to monitor the health of a CDMA wireless system or assist in geolocation. These auxiliary receivers may even be used by law enforcement and military operators for non-cooperative monitoring of a CDMA system for drug-interdiction, counter-terrorism and international intelligence gathering. In these cases, the auxiliary receiver must contend with a wide range of received power levels. Often the auxiliary receiver may need to receive a signal from a mobile station whose received power level is far below (30 dB or more) below the strongest arriving signal.
[0009] A need therefore exists for enabling a user in a CDMA system to receive user signals in the presence of interference from other users when the power level of all co-channel signals is not adjusted to be substantially the same.
SUMMARY OF THE INVENTION
[0010] In accordance with an aspect of our invention, we combine concepts from space-time adaptive processing (STAP), interference cancellation, and multi-user detection (MUD) in multiple embodiments that are able to extract low-level CDMA signals in dense multi-user environments. The performance of these embodiments depends on the accuracy of the signal reconstruction and cancellation. This is particularly crucial if there is a wide range in received power (e.g., from lack of power control). For example, if there is an interfering signal that is 30 dB stronger than the signal we wish to receive and this signal is cancelled with 90% accuracy (meaning that 90% of the interfering signal power is canceled), then the residual portion is still 20 dB above the desired signal. Thus, in addition to symbol detection accuracy, channel estimation accuracy becomes very important in reducing the cancellation residuals.
[0011] Our invention utilizes adaptive temporal reconstruction filter (ATRF) techniques for reconstructing the signal interference. This novel approach permits very accurate channel estimation and signal cancellation. Through our novel use of ATRF, individual multipath components do not need to be tracked and separately estimated. The ATRF recreates the multipath channel structure with accurate amplitude and phase estimates for each component. The use of cost estimation techniques within the ATRF further minimizes cancellation residuals. In addition, cancellation timing errors are mitigated because the filter weights do not need to be exactly centered around the main multipath peak in order to solve for them accurately.
[0012] There has been extensive work on combined successive interference cancellation and multi-user detection systems. Much of this work is focused on simple channel estimation techniques, such as averaging the outputs of the conventional detector's correlators in order to estimate the amplitude and phase of signals to cancel. The reasons for this are that this approach is simple to describe, simulate and implement and the focus is most often on applications where power control is available to the receiver. Thus, small inaccuracies in cancellation do not significantly affect the performance. Also, there are only a limited number of multipath components which are strong enough to be worth tracking and canceling.
[0013] There has also been some work on channel estimation for MUD with the more theoretical motivation of determining the limits of estimation accuracy. These works have often focused on complex maximum likelihood approaches. Because our invention applies successive interference cancellation to complex, non-discrete multipath channels encountered in the real world, our invention takes transmit filtering into account and compensates for timing errors. Our approach minimizes residuals and estimates all multipath components without the need to track them individually.
[0014] Through the addition of STAP, the receiver is able to spatially separate the signals using array (smart antenna) receiver technology. This allows the STAP receiver to place spatial beam pattern nulls on strong interferers. In addition, the STAP receiver combines multipath energy, including both the resolvable multipath that is captured by the rake receiver, as well as unresolved multipath that the rake receiver cannot effectively exploit. We combine these techniques with MUD approaches, where the receiver jointly operates on the received waveform to extract signals for all users simultaneously. By carefully estimating higher level signals and canceling them from the array data for the STAP receivers for lower-level signals, the combined STAP-MUD approach is much more effective than either approach implemented individually.
[0015] In multi-user detection (MUD), code, timing and possibly channel information associated with multiple users are jointly used to better detect each individual user. Thus, at the outputs of a conventional MUD detector, each user sees less multiple access interference and enjoys improved performance. One form of multi-user detection known as interference cancellation estimates, reconstructs and subtracts interfering signals out of the received signal. Unlike the traditional CDMA detectors, interference cancellation MUD utilizes information about other users when detecting a single user. One aspect of our invention is the novel combination of these interference cancellation MUD techniques and adaptive minimum cost channel estimation in the reconstruction of signals. This combination improves performance of signal reconstruction including symbol detection accuracy and channel estimation fidelity.
[0016] Using this combination, we have demonstrated that the STAP-MUD receiver can operate independently of power control, extracting waveforms that are over 35 dB below the strongest arriving CDMA signals.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] FIG. 1 is a network diagram illustrating a typical wireless CDMA network.
[0018] FIG. 2 is a network diagram of an illustrative embodiment of a SIC-MCCE combination system in accordance with our invention.
[0019] FIG. 3 depicts an illustrative conventional detector for the combination of FIG. 2 .
[0020] FIG. 4 depicts an illustrative respread processor for the combination of FIG. 2 .
[0021] FIG. 5 depicts an illustrative adaptive temporal filter (ATRF) for the combination of FIG. 2 .
[0022] FIG. 6 is a flow diagram illustrating a method of operation for the SIC-MCCE combination system of FIG. 2 .
[0023] FIG. 7 is a network diagram of an illustrative embodiment of a SIC-JMCCE combination system in accordance with our invention.
[0024] FIG. 8 is a network diagram of an illustrative embodiment of a SIC-MF-MCCE combination system in accordance with our invention.
[0025] FIG. 8 a is a flow diagram illustrating a method of operation for the SIC-MF-MCCE combination system of FIG. 8 .
[0026] FIG. 9 is a network diagram of an illustrative embodiment of a PIC-MCCE combination system in accordance with our invention.
[0027] FIG. 10 is a flow diagram illustrating a method of operation for the PIC-MCCE combination of FIG. 9 .
[0028] FIG. 11 a is a partial network diagram of an illustrative embodiment of a PIC-JMCCE combination system comprising an ATRF in each parallel processor in accordance with our invention.
[0029] FIG. 11 b is a partial network diagram of an illustrative embodiment of a PIC-JMCCE combination system comprising a single ATRF processor in accordance with our invention.
[0030] FIG. 12 is a network diagram of an illustrative embodiment of a STAP receiver in accordance with our invention.
[0031] FIG. 13 is a network diagram of an illustrative embodiment of a stage in a STAP/VSIC-MCCE combination system in accordance with our invention.
[0032] FIG. 14 is a network diagram of an illustrative embodiment of a J-STAPSIC combination system in accordance with our invention.
[0033] FIG. 15 depicts an illustrative J-STAPSIC stage for the combination of FIG. 14 .
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0000] I. Interference Cancellation MUD Combined with Adaptive Temporal Channel Estimation
[0034] Interference cancellation can take the form of either successive interference cancellation or parallel interference cancellation. FIG. 2 depicts one illustrative embodiment of our invention comprising a system 200 combining successive interference cancellation (SIC) and adaptive minimum cost channel estimation (MCCE) for enabling a CDMA receiver to receive signals at different power levels in the presence of interference from other users. We shall refer to this combination as the SIC-MCCE system. The SIC-MCCE system 200 can be implemented as a component within an auxiliary CDMA receiver or within a CDMA base station receiver system.
[0035] The illustrative system of FIG. 2 comprises a control processor 202 and a plurality of processors 204 combining successive interference cancellation (SIC) multi-user detection and adaptive temporal reconstruction filters (ATRF). The plurality of SIC-ATRF processors 204 are arranged in successive stages. At each stage, the next user is decisioned, respread, temporally reconstructed, and subtracted out by the SIC-ATRF processor associated with that stage. The output of the SIC-ATRF processor in the first stage, a cleaned received signal, is used as the input to the SIC-ATRF processor in the second stage and the output of the processor in the second stage is used as input to the processor in the next stage. This arrangement is continued for each stage. The number of stages used by the SIC-MCCE system is determined based on the total number of users for the system.
[0036] Each SIC-ATRF processor 204 includes a conventional detector 206 , a respread processor 208 , an adaptive temporal reconstruction filter (ATRF) 210 , and a complex mathematical processor 212 . The conventional detector 210 is connected to the respread processor 208 and the mathematical operations processor 212 of the SIC-ATRF processor in the previous stage. For the SIC-ATRF processor 204 in the first stage, the conventional detector 210 is connected to an external entity providing a processed version of the received signal r(t) and to the respread processor 208 . The respread processor 208 is in turn connected to the ATRF 210 , which is connected to the mathematical operations processor 212 . The output of the mathematical operations processor 212 is connected to the conventional detector 208 of the SIC-ATRF processor of the next stage and the mathematical operations processor 212 of the next stage. For the SIC-ATRF processor 204 in the first stage, the mathematical operations processor 212 is connected to the external entity providing a processed version of the received signal r(t) instead of the mathematical operations processor 212 of a previous stage.
[0037] The exact format of the conventional detector and respread processor will differ based on the modulation, coding, and spreading schemes of the particular CDMA system utilized in the wireless receiver system. Although the conventional detector and respread processor can be designed based on third generation CDMA, CDMA2000, or W-CDMA technology, FIGS. 3 and 4 are block diagrams of the conventional detector 206 and respread processor 208 of the embodiment of FIG. 2 according to an illustrative IS-95 implementation. In this implementation, the conventional detector can be an IS-95 conventional detector or an IS-95 rake conventional detector.
[0038] The IS-95 conventional detector 206 , shown in FIG. 3 , is a fundamental component of standard IS-95 receivers. The IS-95 conventional detector 206 comprises three parts: a short code despreader 31 , a long code despreader 32 , and a 64-ary matched filter bank 33 . The short code despreader 31 separately multiplies the received signal by the real and imaginary components of the IS-95 short code, denoted by p i (t) and p q (t). The delays of these components are adjusted to match the offset in time of the intended received signal. Next, the resulting despread signals are recombined, using time delays as illustrated in FIG. 3 , and multiplied by a local copy of the long code, p l (t) corresponding to the desired user in the long code despreader 32 . The long code is also offset according to the expected delay of the arriving signal. The resulting signal is used as input to a 64-ary matched filter bank 33 . The 64-ary matched filter bank 33 contains copies of each of the 64 possible Walsh symbols that could be transmitted during a symbol period. The 64 outputs of the matched filter bank contain the squares of the absolute values of the inner products between the signal at the matched filter bank input and each of these 64 potential symbols. This process may be equally accomplished using a Walsh-Hadamard transform. When the IS-95 conventional detector is used alone, the matched filter bank output with the largest value determines the receiver's estimate of the transmitted symbol during a particular symbol period.
[0039] The IS-95 conventional rake detector, a standard technique employed in practice, embodies several instantiations of the IS-95 conventional detector. Each detector uses the same long and short code, however a different delay is applied to each constituent IS-95 conventional detection. The delays correspond to different multipath components, so that a different IS-95 conventional detector tracks each significant multipath component. The outputs from the 64-ary matched filter banks of each of the IS-95 conventional detectors are combined in the IS-95 rake conventional detector using a non-coherent combining technique. Several non-coherent combining techniques are available; however, a simple example is the equal-gain combiner, in which the power from the corresponding ports from each of the 64 matched filter bank outputs in the constituent IS-95 conventional detectors are added, resulting in 64 new variables. These variables are compared, and the one with the largest power is selected as the receiver's estimate of the transmitted symbol from a 64-ary alphabet.
[0040] The respread processor 208 , shown in FIG. 4 , is used as a fundamental component of IS-95 receivers employing interference cancellation. The respread processor 208 uses as inputs the symbol decisions obtained from either the IS-95 conventional detector, the IS-95 conventional rake detector, or the IS-95 STAP detector, or other similar sources. The respread processor creates a symbol from the 64-ary alphabet corresponding to the selected symbol. Next the symbol is spread using the IS-95 long code, p l (t), then the result is spread using the complex short code using the offset quadrature method specified in the IS-95 standard. The respread processor then matches the resulting signal to the signal received from the antenna using minimum mean square error techniques.
[0041] FIG. 5 is a block diagram of the ATRF 210 of the embodiment of FIG. 2 . The ATRF 210 comprises tap weights 62 , a tap delay line 61 , and a mathematical summing circuit 63 . In addition, the ATRF has an MCCE weight update processor 64 . This processor may be located within the ATRF or as a separate entity between the mathematical operations processor 212 and the ATRF 210 as shown in FIG. 6 . The tap weights contain the amplitude, phase, and multipath structure of the received signal for the kth user. The length of the ATRF should be at least as long as the transmit filter (e.g., for IS-95 the transmit filter is 12 chips in duration), and ideally should be long enough to accommodate the delay spread of the signal (to recreate all multipath components).
[0042] FIG. 6 shows a flow diagram of the operation of the system 200 of our invention. After initial processing such as downconversion to baseband is performed on the received signal by an external entity, the control processor 202 orders the user signals according to a pre-defined methodology (step 605 ). The user signals are then assigned to a stage based on the ordering. For example, the signal for user A is assigned to the first stage; the signal for user B is assigned to the second stage; and the signal for user k is assigned to the k th stage.
[0043] An illustrative methodology ranks signals in descending order of received powers. An advantage of this methodology is that by canceling the strongest users first, the remaining users receive the largest benefit from MAI reduction. In alternative methodology, the control processor identifies signals above a certain threshold without performing a hard ranking of each signal.
[0044] Based on the ordering, the control processor 202 communicates a separate user code to the conventional detector 206 in each stage of the system (step 610 ). For example, the first stage receives the user code associated with user A. In the first stage of the system 200 , the conventional detector 206 despreads the received signal and estimates the symbol transmitted for the identified user, Ŵ l (t) (step 620 ). The technique used in the IS-95 conventional detector and IS-95 rake conventional detector is discussed above.
[0045] In step 630 , the symbol estimate generated by the conventional detector 206 is mixed with the user codes in the respread processor 208 to generate a scaled estimate of the transmitted signal for the user. Using the scaled estimate as input, the ATRF 210 estimates the channel for the user, (i.e., the multipath components and their associated amplitudes and phases) and reconstructs the signal interference associated with the user signal (step 640 ). The reconstructed signal for the user is then cancelled from the total received signal r(t) in the mathematical operations processor 212 (step 650 ). The output of the mathematical operations processor 212 is then input to the SIC-ATRF processor 203 in the next stage of SIC-MCCE system 200 . The output is also fed back to the MCCE weight update processor 64 . Steps 620 through 650 are successively repeated for each of the k stages.
[0046] A more detailed description of the basic SIC-MCCE channel estimation and reconstruction performed in the ATRF 210 is described below. In a preferred embodiment, the adaptive technique used for channel estimation is based on minimum cost estimation techniques.
[0047] In basic SIC-MCCE channel estimation (step 640 in FIG. 6 ), the MCCE weight update processor 64 determines the adaptive filter tap weights 62 that minimize a pre-determined cost function between the received signal and the output of the adaptive filter. In an illustrative mode of operation, the MCCE weight update processor functions as follows. The output of the jth stage is given by:
r ( j ) ( l T s ) = r ( l T s ) - ∑ k = 0 j - 1 ∑ n = 0 N - 1 w k , n s ^ k ( ( k - n ) T s )
this is expressed in vector form as:
r l (j) =r l −w H B l H
where r l is the vector of received signals at time index I, and samples of the reconstructed waveform are contained in the vector:
ŝ k,n [ŝ k ( nT s ) ŝ k (( n+ 1) T s ) . . . ŝ k (( n+Q− 1)T s )]
S ^ k , l = [ s ^ k , l s ^ k , l - 1 ⋮ s ^ k , l - N + 1 ] B l H = [ S ^ 0 , l ⋮ S ^ j - 1 , l ]
[0048] Different weight vectors can be obtained by using minimizing different cost functions, each of which represents the quality of the performance of the SIC stage in some manner. One implementation of the minimum cost channel estimate solution is the minimum mean square error solution. The minimum mean square error solution for the weight vector w is the solution that minimizes the following cost function:
J ( w )=| r l (j) | 2 =|r l −w H B l H | 2
which simultaneously minimizes both the residual at the output of the j th stage of the SIC receiver and the difference between the ATRF filter output and the received data r l . The solution to this problem is obtained using standard techniques, where we obtain:
w =( B l H B l ) B l H r l H
[0049] Since this solution minimizes the mean square error between the ATRF filter output and the received data at this input to the stage, this is called the minimum mean square error (MMSE) solution. In an alternate illustrative embodiment of our invention, the channel is estimated jointly over multiple users. We will refer to this combination of a jointly optimized ATRF and SIC multi-user detection as the SIC-JMCCE system. An illustrative multi-stage SIC-JMCCE system is shown in FIG. 7 . The SIC-JMCCE system 700 comprises a similar structure as the SIC-MCCE system. However, in the SIC-JMCCE system 700 , the outputs of the respread processors 208 for all previous stages are communicated as inputs to the ATRF filter 710 of the current stage. For example, the SIC-ATRF processor in the third stage of a SIC-JMCCE system uses the output of the first stage respread processor and the second stage respread processor as inputs to the third stage ATRF.
[0050] The mode of operation in accordance with the SIC-JMCCE system is as described above for the SIC-MCCE system, FIG. 6 . However, the channel estimation step 640 is modified to estimate the channel over multiple users. During channel estimation, the tap weights 62 of the current stage ATRF 710 are determined by jointly minimizing the cost function between the received signal and the sum of the outputs of the ATRFs 710 of previously completed stages. The ATRF 710 for each stage jointly estimates and reconstructs all of the currently detected signals including those detected in previous stages of SIC-JMCCE. Thus, the symbols of a single user are detected in each stage (step 620 ), but the temporal signal structures of all previous detected users are re-estimated and cancelled at each stage. At step 650 , the output of the current stage ATRF 710 consisting of all the currently detected signals is subtracted from the received signal in the mathematical operations processor 212 .
[0051] The above approaches to channel estimation in accordance with our invention reconstruct the temporal structure of the signals. However, these approaches do not take into account the frequency content of the signals. In another illustrative embodiment, the ATRF is extended to take into account Doppler spread. We refer to this combination of SIC multi-user detection and multiple frequency adaptive reconstruction as a SIC-MF-MCCE system. The MF-MCCE ATRF can be implemented either in an independent or joint arrangement. An independent MF-MCCE ATRF is shown in FIG. 8 . In this arrangement, a frequency shift processor 814 is connected between the respread processor 208 and the ATRF 810 in each stage of the system.
[0052] The mode of operation in accordance with the independent SIC-MF-MCCE system is shown in FIG. 8 a . In this mode, steps 605 through 630 are identical to those described for the SIC-MCCE and SIC-JMCCE systems. However, an additional step (step 835 ) is added to shift the frequency of the signal output from the respread processor to take into account Doppler spread and un-compensated frequency tracking errors. The output of the frequency shift processor 814 is then used as input to the MCCE weight update processor 64 . At step 840 , the ATRF 810 estimates the channel using either the basic or joint technique previously discussed. The following is a more detailed description of the operation of the MF-MCCE ATRF in accordance with a preferred embodiment of our invention. ŝ k,p,n represents a row vector containing Q samples of the reconstructed signal for user k, from time nT s to (n+Q−1)T s , and frequency shifted by (p−P/2)/(QT s ) Hz:
s ^ k , p , n = [ s ^ k ( nT s ) ⅇ j 2 π ( p - P 2 ) ( n ) / Q s ^ ( ( n + 1 ) T s ) ⅇ j 2 π ( p - P 2 ) ( n + 1 ) / Q … s ^ ( ( n + Q - 1 ) T s ) ⅇ j 2 π ( p - P 2 ) ( n + Q - 1 ) / Q ]
r l represents a row vector containing the Q samples of the received signal, r(nT s ) through r((n+Q−1)T s ). Then at stage j, the cleaned signal is:
r l (j) =r l −w H B l
where
B l = [ A 0 , l ⋮ A j - 1 , l ] , A k , j = [ S ^ k , 0 , l ⋮ S ^ k , P - 1 , l ] , S ^ k , p , l = [ s ^ k , p , l + N / 2 s ^ k , p , l + N / 2 - 1 ⋮ s ^ k , p , l + N / 2 + 1 ]
Using these equations, the MF-MCCE ATRF 810 determines the filter tap weight vector that minimizes the cost function set for the ATRF. For example, where a minimum mean square error cost function is used, the ATRF 810 determines the weight vector according to the following equations.
J ( w )=∥ r l −w H B l ∥ 2
which gives:
w =( B l B l H ) −1 B l r l H
The MF-MCCE ATRF 810 applies this weight vector to the delayed and frequency shifted version of the signal received from the previous stage (or the antenna input if this is the first stage).
[0054] The SIC detection approach is particularly attractive where there is a wide range in received powers (e.g., due to lack of power control). The SIC approach exploits the power distribution by canceling based on signal strength ordering. For applications where signals are received at about the same power (e.g., through power control), the PIC approach is often preferable.
[0055] The combination of interference cancellation and ATRF channel estimation can also be extended to parallel interference cancellation techniques. FIG. 9 depicts one stage of a system 900 combining parallel interference cancellation (PIC) and adaptive minimum cost channel estimation (MCCE) according to a further specific illustrative embodiment of our invention. We shall refer to this system as a PIC-MCCE system. In the PIC-MCCE system 900 , rather than detecting one additional user at each stage of the detector as in the SIC-MCCE system 200 , every user is detected anew at each stage.
[0056] The PIC-MCCE system 900 includes a plurality of parallel processors 905 . The number of processors can vary but is typically determined by the number of users associated with the system. Each processor is comprised of a conventional detector 206 , a respread processor 208 and an ATRF 910 . The conventional detector 206 in each parallel processor 905 is connected to a respread processor 208 and to a single external entity that communicates the received signal r(t) as input to the conventional detector. The ATRF 910 in each parallel processor 905 is connected between a respread processor 208 and a series 913 of mathematical operations processors 212 . Alternatively, a partial summer circuit could be substituted for the series of mathematical operations processors. The series of mathematical operations processors 913 (or alternatively the partial summer circuit) is connected to the ATRF 210 in every parallel processor 905 and to the external entity providing the received signal.
[0057] The conventional detector 206 and the respread processor 208 are identical to the conventional detector 206 and respread processor 208 used in the SIC-MCCE embodiment. In addition, a control processor 902 could optionally be included to provide ordering of the signals prior to processing by the PIC-MCCE system.
[0058] FIG. 10 shows a flow diagram of the operation of each processor 905 of the embodiment of FIG. 9 . After initial processing such as downconversion to baseband is performed on the received signal by an external entity, the received signal is sent in parallel to each of the processors 905 in the first stage of the PIC-MCCE system. The conventional detector 206 in each processor 905 determines the initial symbol decision estimate for the user assigned to that processor (step 1010 ). In each processor 905 , the initial symbol estimate is communicated to the respread processor 208 . The respread processor 208 generates a scaled estimate of the transmitted signal waveform for the user (step 1020 ). After respreading, each user is temporally reconstructed in the ATRF 910 (step 1030 ).
[0059] The outputs from the ATRF 910 in each processor are sent in parallel to the series of mathematical operations processors 913 (or alternatively to the partial summer). The mathematical operations processors 212 sum up all signals but one for each output, thus, forming an estimate of the interference for each user (step 1040 ). This interference estimate is then subtracted out of the received signal (step 1050 ). This process can be repeated for multiple PIC stages until the signal converges. At each stage, different numbers of users are successfully detected. Typically, as the number of stages increases, the number of users successfully detected increases, although oscillatory conditions can also occur. We define convergence as occurring at the stage after which no substantial increase is obtained in the number of successfully detected stages. The number of repetitions can be fixed or under dynamic control. Due to the computational complexity of repeating the PIC-MCCE stages, a preferred implementation defines the optimal number of repetitions.
[0060] A first approach to channel estimation in the PIC structure is the same as described above for basic SIC-MCCE channel estimation. A joint MCCE channel estimation approach, described above for the SIC-JMCCE system, can also be applied to the parallel structure. We refer to this system as PIC-JMCCE.
[0061] A partial PIC-JMCCE system is shown in FIG. 11A according to an illustrative embodiment of our invention. In this embodiment, each processor 905 of the PIC-JMCCE system has an individual ATRF 911 . In a system with k users, each ATRF 911 receives k input signals, one from each of the respread processors 208 in the other parallel processors 905 . Each ATRF 911 processes the signals as described above for step 544 of SIC-JMCCE processing.
[0062] An alternative embodiment of the PIC-JMCCE system is shown in FIG. 11B , having a single ATRF 912 . In this embodiment, each processor 905 has a conventional detector 206 and a respread processor 208 . The output of the respread processor 208 in every parallel processor 905 is communicated as input to the single ATRF 912 . In the PIC-JMCCE receiver, since the channels are estimated simultaneously for all successfully detected signals, only a single ATRF module is needed at each state, however, this ATRF module produces channel estimates for all signals. After reconstruction, the ATRF outputs the signal interference associated with each user to the series of mathematical operations processors 913 .
[0063] A third approach to channel estimation, PIC-MF-MCCE, extends the ATRF to account for Doppler spread. This approach is identical to the approach described above for SIC-MF-MCCE. In the PIC-MF-MCCE arrangement, a frequency shift processor 814 is connected between the respread processor 208 and the ATRF 810 in each parallel processor 905 of the system.
[0064] The above embodiment assumes that all signals are used in the PIC-MCCE system at each stage. This condition can be relaxed to include groups of signals at each stage. For example, a control processor could be used to order the received signals in groups of similar power and successively detect groups of users in parallel. Similarly, the PIC-JMCCE system need not include all previously detected signals at each stage, but possibly, some subset of them.
[0000] II. Application of STAP to Systems Without a Pilot Reference Signal
[0065] Through the use of space time adaptive processing (STAP), a receiver is able to spatially separate user signals using array (smart antenna) receiver technology. This feature allows a STAP receiver to place spatial beam pattern nulls on strong interferers. In addition, the STAP receiver combines multipath energy, including both the resolvable multipath that is captured by a rake receiver, as well as unresolved multipath that the rake receiver cannot effectively exploit.
[0066] A single user space time adaptive processing (STAP) receiver is depicted in FIG. 12 in accordance with an illustrative embodiment of our invention. The STAP receiver 1200 includes a plurality of filters 1250 , one per antenna, in a parallel arrangement, a mathematical summation processor 1270 for combining the outputs of all the filters prior to detection, a conventional detector 206 , a respread processor 208 , mathematical operations processor 212 , and an MCCE weight update processor 64 . The receiver in FIG. 12 also can include implementations with a one time tap per antenna (spatial adaptive signal processing) or with a single antenna element and multiple time taps (single element adaptive rake receiver). Each filter 1250 contains a tap delay line 1252 , a series of STAP weights 1254 , and a summation processor 1256 . In a traditional STAP receiver, the STAP weights in the filter 1250 can be trained using a known pilot signal. However, a key complication in applying STAP to the IS-95 reverse link is that there is no pilot present in the received signal. Our invention provides innovative processes for blind adaptation where no pilot signal exists to train the filter weight.
[0067] An illustrative embodiment of our invention comprises a space time adaptive processing (STAP) processor, means for hypothesizing possible symbols transmitted during a symbol period, a respread processor, means for weight computation wherein the hypothesized symbol and the vector input symbol are used to form a set of STAP weights which filter the input data spatially and temporally, a matched filter bank, means for determining a metric to measure the quality of the matched filter bank, and means for comparing generated metrics. The STAP processor includes a plurality of filters, each comprising a set of STAP weights, and a plurality of mathematical summation circuits. In addition, each filter may also include a tapped delay line. In a preferred IS-95 implementation, the matched filter bank is a bank of 64 matched filters that correspond to the 64 possible Walsh symbols.
[0068] When a user signal is received by the antenna array, the user signal from each antenna in the array is first downconverted to baseband in a processor (not shown) and sampled. Downconversion and sampling are performed by an external processor. After the resulting signal r 1 (t), r 2 (t), . . . r M (t) is received, a metric is determined associated with a hypothesized symbol value. The metric used may also be referred to as the sharpness factor. The step of determining a metric is repeated for each of the possible 64 Walsh symbols. The resulting 64 metrics are compared in the comparison means to determine the best estimate for the transmitted signal. This estimate is the output of the blind adaptive STAP detector.
[0069] A more detailed description of the metric determination step is described below. After the input signal vector is received, the hypothesizing means hypothesizes which symbol was transmitted. The hypothesized symbol is communicated to the respread processor and spread to create a replica of the transmitted waveform. The replica of the transmitted waveform and the input signal vector are input to the weight computation means. The weight computation means uses these inputs to determine the appropriate STAP weights for the STAP filters. After the determination is made, these STAP weights are communicated to the filters and applied to each signal vector component, r 1 (t), r 2 (t), . . . r M (t). Before application of the STAP weights, a tapped delay line may be applied to each component of the input signal vector. After application of the STAP weights, the weighted signals from every antenna are combined in a mathematical summation circuit. The output of the summation circuit is despread and input into the matched filter bank. The matched filter bank generates a metric associated with the hypothesized symbol.
[0070] In an alternate embodiment, the STAP processor may despread the delayed signals from each antenna element and then apply the STAP weights. After the STAP weights are applied, the results are summed and used as input to the matched filter bank.
[0071] For example in IS-95, the sharpness factor is computed by taking the ratio of the peak output (i.e., for the most likely transmitted symbol) to the sum of the outputs for all the other 63 hypothesized Walsh symbols. The sharpness factor can also be based on the distance between the peak output and the average of all other outputs. In either case the STAP solution with the largest sharpness factor is chosen to determine the correctly hypothesized symbol. This embodiment can be extended across multiple symbols where we hypothesize all combinations of multiple symbols.
[0072] In an alternative embodiment, the STAP filter weights are determined based on a combination of “known” symbols and hypothesized symbols. The known symbols may be obtained by feeding back previously detected symbols, or from a priori known pilot reference symbols. Utilizing the known symbols allows extension of the length of the training sequence without requiring additional hypothesized symbols. It also anchors the hypothesized STAP solutions to a partially known training sequence, which makes it more likely that the correctly hypothesized solution will stand out. The above embodiments can be repeated for each symbol. These procedures can also be utilized to detect initial symbol(s), and then utilize an update procedure to compute the STAP weights for the remaining symbols. In other words, the STAP weights of the previous symbol can be used to detect the current symbol which can then in turn be used to update the STAP tap weights for the next symbol.
[0000] III. Combined STAP and MUD
[0073] The STAP receiver shown in FIG. 12 is limited in several ways. First, it can only effectively null M−1 high level signals (including temporally resolvable multipath components) where M is the number of antennas used. Therefore, it is only effective at extracting the M strongest signal components. Another embodiment of our invention combines MUD and temporal interference cancellation techniques and thus, removes much of the interfering signals before applying the STAP receiver. This approach frees up STAP degrees of freedom to operate on the remaining interference more effectively.
[0074] FIG. 13 depicts a single stage of a system 1300 combining STAP, interference cancellation MUD, and minimum cost channel estimation (MCCE) according to a specific illustrative embodiment of our invention. The illustrative embodiment of our invention shown in FIG. 13 applies SIC (e.g., SIC-MCCE or SIC-JMCCE) to each antenna element separately. We shall refer to this system as the STAP/VSIC system where the V refers to the vector nature of the cancellation process. The multi-stage STAP/VSIC receivers resemble the multi-stage SIC receivers of FIGS. 2, 4 , and 5 , except that the received signal and cleaned received signals are now vectors of size M.
[0075] A single stage of the STAP/VSIC system includes a STAP processor 1200 , a plurality of ATRFs 1210 , and a plurality of mathematical operations processors 212 . The STAP processor can be a standard STAP processor or a blind adaptive STAP processor. In an illustrative embodiment of our invention, the STAP processor includes a plurality of filters 1250 , a mathematical operations processor, and a conventional detector. In an alternate embodiment, the STAP processor may include a respread processor and may also include a MCCE weight update processor.
[0076] When a user signal is received by the antenna array, the user signal from each antenna in the array is first downconverted to baseband in a processor (not shown) and sampled. For each antenna, the resulting signal, r 1 (t), r 2 (t), . . . r M (t), is communicated to the STAP processor 1200 . After processing by the STAP filters, conventional detector, and respread processor as described in the embodiments above, the output of the respread processor, a vector estimate of the transmitted signal for the user, is communicated to the ATRFs 1210 , one per antenna. Each ATRF 1210 then estimates the channel associated with the signal and reconstructs the signal interference. The methods used for channel estimation in the STAP/VSIC system can be either basic MCCE, JMCCE, or MF-MCCE techniques. Each reconstructed signal is then cancelled from the total received input for that antenna in a mathematical processor 212 . The output of the plurality of mathematical processors, one per antenna, is then used as the vector input to the next STAP/VSIC stage.
[0077] The STAP/VSIC system approach can also be extended to vectorized parallel interference cancellation. We shall refer to this system as the STAPNPIC system. In these embodiments, the system would take the form of the PIC detector shown in FIG. 9 with the conventional detector replaced by the one of the above described embodiments of a STAP processor.
[0078] Another embodiment of our invention combines STAP with interference cancellation techniques. In this embodiment, the system jointly solves for the ATRF tap weights and STAP tap weights. For example, the system minimizes the error associated with the cost function between the transmitted symbol replica and the sum of the STAP filter outputs and ATRF filter outputs. FIG. 14 depicts one illustrative embodiment of our invention. We shall refer to this system as the J-STAPSIC system.
[0079] The illustrative system of FIG. 14 comprises a plurality of J-STAPSIC processors arranged in successive stages 1404 . The input to the J-STAPSIC system 1400 is a vector of size M where M is equivalent to one received signal stream for each antenna element). Each stage utilizes the symbols of all previously detected users, and detects one additional user's symbols. The number of stages, K, is equivalent to the total number of users associated with the system.
[0080] An illustrative embodiment of a k th J-STAPSIC stage 1404 is shown in FIG. 15 . Each J-STAPSIC stage comprises a plurality of STAP filters 1252 , one per antenna, in a parallel arrangement, a plurality of respread processors, one per previous stage, in a parallel arrangement for receiving the symbol estimates from the previous J-STAPSIC stages, a plurality of ATRF filters 1410 , one per previous stage, a mathematical summation circuit 1414 for summing the outputs of the plurality of STAP filters, a mathematical summation circuit 1414 for summing the outputs of the plurality of ATRF filters, a mathematical operations processor 212 for adding the outputs of the mathematical summation circuits 1414 , a conventional detector 206 , and a respread processor 208 .
[0081] In the k th stage, the plurality of STAP filters 1252 receive a cleaned vector received signal, r 1 (t), r 2 (t), . . . r M (t) from the previous stage and the plurality of parallel respread processors receive a vector comprising symbol estimates determined in the previous stage. In each parallel respread processor, the symbol estimates are spread. The mathematical summation circuit 1414 sums the outputs from the plurality of the STAP filters and another mathematical summation circuit sums the outputs from the plurality of ATRF filters. The outputs of these summation circuits are then combined in a mathematical operations circuit 212 . Using the output of the mathematical operations circuit 212 , the conventional detector despreads the input and estimates the symbol transmitted. The symbol estimate is then spread by the respread processor. The output of the respread processor is combined with the output of the conventional detector and is used as input to an MCCE weight update processor. The MCCE weight update processor then updates in parallel the tap weights of the plurality of STAP and ATRF filters.
[0082] Although the invention has been shown and described with respect to exemplary embodiments thereof, it should be understood by those skilled in the art that various changes, omissions and additions may be therein and thereto, without departing from the spirit and the scope of the invention. | Methods and systems in a wireless receiver for enabling the reception of input signals at varied power levels in the presence of co-channel interference utilizing combinations of space-time adaptive processing (STAP), interference cancellation multi-user detection (MUD), and combined STAP/MUD techniques. In MUD, code, timing, and possibly channel information of multiple users are jointly used to better detect each individual user. The novel combination of adaptive signal reconstruction techniques with interference cancellation MUD techniques provides accurate temporal cancellation of interference with minimal interference residuals. Additional methods and systems extend adaptive signal reconstruction techniques to take Doppler spread into account. STAP techniques permit a wireless receiver to exploit multiple antenna elements to form beams in the direction of the desired signal and nulls in the direction of the interfering signals. The combined STAP-MUD methods and systems increase the probability of successful user detection by taking advantage of the benefits of each reception method. An additional method and system utilizes STAP techniques in the case where no pilot signal is available. This method compares the outputs of various hypothesized STAP solutions. | 7 |
This invention concerns miniature table clocks of the type in which the case exhibits rounded forms and is arranged so as to be able to occupy two positions of stable equilibrium, a first in which the dial is hidden and a second in which the dial is visible, the clock then being supported on the back cover of the case.
BACKGROUND OF THE INVENTION
A miniature clock of this type is described in the German Utility Model 1.833.188. The case of this clock includes a front glass and a back cover in the form of a hemispheric cap, provided with a flat portion forming a support surface and which defines a first position of stable equilibrium. This clock further includes a ballast mass proximate said surface.
It is likewise possible to have the clock rest in a second position of stable equilibrium supported on its glass. These two positions are defined by planar surfaces. The clock thus obtained shows great stability. Thus, to unbalance it it is necessary to apply a force such that the resultant defined by this force and the weight of the clock is located on a straight line coming out of the support surface.
A purpose of this invention is on the contrary to provide a clock readily movable about its second equilibrium position.
Furthermore, in view of its hemispherical form, the clock as described hereinabove exhibits a squat and heavy aspect.
A further purpose of this invention is to provide an article having a lighter form.
SUMMARY OF THE INVENTION
These purposes are attained in a miniature table clock including a case provided with a front glass and a back cover in the form of a cap, an arrangement for displaying the time of day covered by the glass and positioning means defining two positions of stable equilibrium, a first position in which the case rests on its front face and a second position in which the case rests on the back cover, said back cover including a first zone defined by a first convex surface a portion of which serves to bear the clock in its second equilibrium position and a second zone defined by a second convex surface surrounding the first zone, the mean radius of curvature of the first surface being less than the mean radius of curvature of the second surface.
An embodiment of the miniature clock in accordance with the invention is schematically shown by way of example in the annexed drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an elevational view looking at the dial;
FIG. 2 is a profile view with cut away portions;
FIG. 3 is a perspective view.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The miniature clock as shown includes a case 10 with a glass 12, a bezel 14 and back cover 16. At the interior of the case are to be found display means including a dial 18 and hands 20 as well as a movement driving the hands 20. This movement is energized by a battery 22. It includes an alarm function controlled by a gravitational switch schematically shown at 24.
Glass 12, slightly convex, is fixed to the bezel 14. Both of these are of circular form. The outer contour of the profile of the bezel 14 is approximately in the form of a quarter of a circle. The edge of such bezel 14 abuts against the edge of the back cover 16. This latter is in the form of a cap, that is to say exhibits a curved and convex surface. The form of this back cover will be defined more precisely hereinafter. The case 10 thus defined has thus rounded forms which give it an agreeable aspect as much in its appearance as in its feel.
A cross-section perpendicular to the dial via the axis 12 o 'clock to 6 o 'clock corresponds to the profile view of FIG. 2, the back cover 16 exhibiting a first arc of circle 26, the center 01 of which is in front of the dial 18 below the axis passing through its center. This arc 26 is connected to the edge of the back cover 16 by a second arc of a circle 28 of small radius centered to the right of the edge of the back cover 16 in order to assure matching with the bezel 14.
In view of the position of the center 01 it is apparent that the upper half of the back cover 16 of the case 10 is thinner than the lower half. The difference in thickness between these two portions of the back cover 16 contributes to the elegance of the clock in a substantial measure.
FIG. 2 shows that the other end of arc 26 matches with a third arc of a circle 30 of smaller radius. The center 02 of arc 30 is located within the back cover 16. This arc 30 forms part of a protruding zone of the back cover 16 which will be described in detail hereinafter. The other extremity of arc 30 matches with a rectilinear segment 32, itself matching with the edge of the back cover 16 by means of an arc of a circle 34 corresponding to arc 28. By matching between these arcs and the described segment it must here be understood that one passes from one of these elements to the neighbouring element with a common tangent, i.e. without a sharp edge.
In other terms, the back cover 16 takes the form of a cap made up of a juxtaposition of portions of ellipsoids, cone and torus, these portions together defining a continuously curved surface. From this it results that neighbouring portions are substantially tangent to one another.
More precisely, the zone neighbouring segment 32 is defined by a portion of a cone generated by the segment 32 turning about the axis of the hands. The edge of the back cover 16 shown on FIG. 2 by arcs 28 and 34 assumes the form of a section of a torus of which the generating axis is common with that of the hands. The other portions of the back cover 16 are defined by a warped surface which may be broken down into a plurality of ellipsoidal portions. All of the portions are arranged in a manner so that they are substantially tangent to one another.
Furthermore, the protruding zone of which arc 30 forms a portion is defined by a part of a sphere the radius of which is subtantially less than the average radius of the neighbouring zone. The dimensional relationship between these radii is typically equal to 1/3.
Thus, the back cover 16 of case 10 is formed by a continuous surface without sharp edges. It exhibits in the center portion of its width and in the lower half a first zone defined by a first convex surface on which the clock is supported in its second equilibrium position and a second zone defined by a second convex surface and surrounding the first zone. The average radius of curvature of the first surface is less than the average radius of curvature of the second surface. Furthermore, the second surface includes, in the portion taken between the first zone and the lower edge of the case, a flattened surface defined by the conical portion and proximate a protruding zone
In all the sections under consideration, the profile of the back cover 16 of the case is naturally closer to the dial 18 than in the section passing through the axis 12 o'clock -6 o'clock of this latter. It follows that the surface of the back cover 16 is entirely situated at the interior of a semi-spherical surface centered in the plane of the edge of the back cover 16 at the intersection with the axis of the hands and having a diameter equal to that of the edge of the back cover, i.e. equal to the diameter of the case itself. The back cover 16 thus has a relatively flat form which gives it its elegance.
A first position of stable equilibrium of the clock as described is that in which the glass 12 or bezel 14 rests on a flat support (work table, desk, night table, etc.). In this position dial 18 is evidently hidden.
In the second position of stable equilibrium shown on FIG. 3, dial 18 is inclined. It is located approximately in a plane perpendicular to the axis of vision of a person seated at the table on which the clock may rest.
To assure the stability of this second equilibrium position, the clock is provided with a counterweight 36 housed in the lower portion of case 10, more precisely at the front and above the portion of case 10 including the flattened surface and engaged in the bezel 14, this latter being hollowed out.
Counterweight 36 thus forms ballast for the clock. This ballast is completed by the battery 22 which is the heaviest component of the clock and which is placed behind the dial and just above the counterweight 36. This latter and battery 22 ballast the clock in a manner such that its center of gravity G is located below point 02. More precisely, the mass and position of the counterweight 36 are chosen in a manner such that the straight line passing through points 02 and G makes an angle of approximately 30° with a surface tangent to the glass.
This angle defines the inclination of the dial in the second equilibrium position of the clock.
Furthermore, the distance between point 02 and point G determines the frequency at which the clock will oscillate when one displaces it from its second point of equilibrium. The frequency is higher in proportion to the increase in this distance.
One may further note that the straight line passing through points 02 and G cut the arc 30 at its end neighbouring segment 32. From this it is evident that the support point of the clock in its second position of stable equilibrium is located in the neighbourhood of the periphery of the protruding zone close to its lower portion. It is thus close to the flattened surface proximate the protruding zone.
Regardless of the point on the back cover 16 of case 10 on which the clock is posed on its plane support, it will tilt until it arrives in its second position of stable equilibrium as described. If the clock should be accidentally pushed from this position of equilibrium, it will thus return thereto.
On the other hand, if, from this second equilibrium position, one exerts pressure from back to front on the clock in the direction of the first position of stable equilibrium, it will be soon supported on the flattened surface of the back cover 16 of its case 10, then will rock immediately pivoted on arc 34. From this instant the center of gravity G of the clock is raised up substantially. A large resistance will thus operate against displacement in the direction as considered and this resistance increases with the amplitude of the displacement. It is only from the instant when the center of gravity passes beyond the vertical from the instantaneous support point of the clock that the latter tends to follow its displacement in the direction of the first position of stable equilibrium.
In view of the conditions as described attending this latter displacement, an accidental push causing the clock to pass from its second stable equilibrium position to its first is most improbable.
A zone of very slightly convex form in place of the flattened surface as described would have a similar effect.
A clock of this type has been constructed. Here by way of example are to be found its basic characteristics.
The edge of the back cover defines a circle of 70 mm diameter. The total thickness of the clock is equal to 30 mm. Arcs 28 and 34 of the edge of the back cover and the arcs of the bezel have a radius of 6 mm. The radius of arc 30 associated with the protruding portion is equal to 20 mm. The center 02 is located 11 mm below the axis of the hands and 10 mm behind the front surface of the clock. Finally, the radius of arc 26 is equal to 59.44 mm while center 01 is located 11 mm below the axis of the hands and at 29.44 mm from the front surface of the clock.
The back cover 16 and bezel 14 are formed by injecting a plastic material known under the name of ABS (acryl butadiene styrene). The counterweight 36 is of lead. It has a mass of 37 grams. Furthermore, the period of oscillation of the clock about its second equilibrium position is on the order of one second.
The clock as described is particularly interesting when it is provided with an audible alarm arrangement which may be manually adjusted and stops automatically in the first position of stable equilibrium, thereby to be usable for alarm.
To this effect, switch 24 is arranged so as to be turned off when the clock occupies the first equilibrium position and turned on when the clock is in its second equilibrium position.
Such switch 24 may advantageously be of the mercury type.
When the alarm is set off, the sleeper still half-conscious who extends his arm to shut off the noise or in order to remove the source or operate an imaginary stop button, will not cause the clock to rock into its first position of stable equilibrium. The alarm will thus not stop. It will continue to manifest itself until the sleeper finally woken up and perfectly conscious, deliberately picks up the clock and places the bezel on the night table.
In this arrangement, the clock constitutes an alarm clock which even a hardened sleeper cannot stop unconsciously and thus pursue his sleep.
The clock as described hereinabove is provided with a back cover 16 which has a continuous curved surface.
In a variant (not shown), it will be possible to provide facets on th back cover in a manner such that the clock would be given a jerky motion when, removed from its second equilibrium position, it returns thereto. Such facets must be very small. Furthermore, it is necessary that the envelope of the back cover thus defined exhibits in the zone neighbouring the point of contact in the second equilibrium position an average radius of curvature less than the radius of curvature of the portion of the back cover surrounding this zone. In order for such solution to be pleasing, it is desirable that the sagitta between the envelope and the facets be constant. In this manner the surface of the facets becomes smaller as the radius of curvature becomes smaller.
In the clock as described and shown, the glass, bezel, back cover and dial have a circular form. It is also possible to obtain these pieces in elliptic or oval forms in respecting nevertheless the conditions as defined hereinabove in order to assure the mobility of the clock about its second equilibrium position. | A miniature table clock is provided with a case having rounded contours. The back (16) of such case exhibits a protruding zone and a flattened surface proximate said zone at the mid portion of its lower half. The clock has two positions of stable equilibrium; a first in which the dial (18) is parallel to the clock support plane and facing thereto and a second in which the clock, appropriately ballasted, rests at a point of the protruding zone adjacent the flattened surface. | 6 |
[0001] This invention was made with Government support under contract No. DE-AC04-94AL85000 awarded by the U.S. Department of Energy to Sandia Corporation. The Government has certain rights in the invention.
FIELD OF THE INVENTION
[0002] The present invention relates to photoacoustic spectrometers and, in particular, to photoacoustic spectrometers having compact, mid-range infrared light sources.
BACKGROUND OF THE INVENTION
[0003] The rapid identification of molecular species has many applications in the areas of science and technology. The determination and measurement of harmful pollutants in the environment also has gained increasing importance as government agencies require industries to meet pollution control standards based on the best available testing technologies. The development of inexpensive equipment that can provide a rapid measurement of chemical species in environmental samples can thus have a wide-ranging application.
[0004] Various spectroscopic techniques monitor the interaction of laser light with a sample by measuring either transmitted or absorbed laser light as a function of wavelength. Many absorption techniques such as frequency modulation and wavelength modulation spectroscopy estimate species according to the derivative of the spectra. These techniques are best suited to detecting small molecules with well defined spectral features as they are not capable of discriminating the broad spectral features of large molecules. The difference between the spectra of a large molecule, such as toluene, and a small molecule, such as NO 2 , are illustrated in FIG. 1. In comparison with small molecules, the spectral features of large molecules generally include fine spectral features over a broad spectral range. It is difficult or impossible for many existing laser-based spectroscopic techniques to quantitatively speciate mixtures of such large molecules.
[0005] Photoacoustic spectrometers, in contrast to most other techniques, analyze a sample according to heat absorption and the resulting pressure waves generated within the sample. Photoacoustic spectrometers are described, for example, in U.S. Pat. No. 3,948,345 to Rosencwaig, incorporated herein by reference. In photoacoustic spectroscopy, a tunable light source is passed through a sample contained in an enclosed cell. As the wavelength of the light source is varied, the sample absorbs light according to it absorption spectra. Absorbed light is converted into heat within the sample that is detectable as an increase in pressure of the contained sample. The photoacoustic spectrum of the sample is the variation of pressure oscillations in a sample with the wavelength of light from the light source. The ability to speciate mixtures of complex molecules requires a light source having an output that is both tunable over the absorption wavelength range of the molecules and narrow enough to capture fine spectroscopic features of the particular molecules. In addition, sufficient power must be available to produce measurable pressure oscillations or pulses in the sample and distinguish these pulses from background noise. Photoacoustic spectrometers are capable of measuring concentrations of complex molecular species at concentrations of parts per billion, and thus have great potential for the rapid speciation of complex toxic compounds in the air.
[0006] Of concern for environmental measurements is the detection of volatile organic compounds (VOCs). The optimum wavelength ranges for detecting VOCs is generally 3-5 μm and 8-12 μm, where atmospheric transmission is good and where functional organic groups, such as the fundamental stretch mode of C—H, strongly absorb. At present there are several promising sources in the mid-range infrared range of 3-5 μm. The most promising sources in the 8-12 μm range are the CO 2 lasers and the quantum cascade diode lasers. The former, however, is only tunable over about 40 discrete lines in the 9 to 11 μm range. The latter are only tunable over about 10 cm −1 per device.
[0007] Tunable light in the mid-range infrared can be generated with available light sources through the interaction of laser light with non-linear optical materials. Typically, the output wavelength is varied by changing some physical property of the non-linear material, such as its temperature or orientation. This technique for generating tunable light is particularly promising for environmental uses, since it has the potential to be robust and relatively maintenance-free. Higher output powers and stable output wavelength can be generated non-linear materials by incorporating them into an optical oscillator.
[0008] A non-linear material that is particularly useful for spectroscopy and chemical sensing is periodically poled lithium niobate (LiNbO 3 ), or PPLN. U.S. Pat. No. 5,434,700 to Yoo, incorporated herein by reference, describes the operation of optical wavelength converters constructed of materials having non-linear optical properties. The non-linear properties of a PPLN crystal can be changed by changing the material temperature or by adjusting the orientation of light relative to the non-linear material structure, such as by rotating the material relative to the incident light path, or by having a material with varying structures and by moving the material so that different portions of these varying structures intercept the incident light.
[0009] While strides have been made in the development of photoacoustic spectrometers, prior art systems have limitations that hinder their use for environmental applications. One of the major limitations is the inability of prior art systems to conduct real-time measurements of mixtures of complex organic compounds. To accomplish this, the light source must be narrow and finely tunable (either continuously, or in steps of a fraction of a wave number) over a broad range (hundreds of wavenumbers). In addition, it must be capable of being used at the place where the environmental measurement is to be made that is it must be portable so that is useful in the field.
[0010] Prior art systems typically use lasers having an output in the several watt range to drive non-linear materials. For example, such systems have used neodymium-vanadate (Nd:Vanadate) pump lasers operating at about 1 μm and generating sufficient power to induce non-linear effects in non-linear materials, such as PPLN. Typically the non-linear material in located in an optical parametric oscillator (OPO) that is tuned to produce light of a wavelength different from the pump laser. While these systems produce usable IR light, there are many problems in adapting them for portable applications, such as real-time environmental measurements. Prior art systems typically have limited tuning capabilities and require large amounts of external power, making it difficult to include them in portable photoacoustic spectrometers.
[0011] What is needed is an improved photoacoustic spectrometer which has a laser system that operates at high efficiency and generates light with a beam profile that efficiently couples into an OPO, which is be capable of speciating gaseous mixtures of complex organic molecules, and which is robust and portable.
SUMMARY OF THE INVENTION
[0012] The present invention solves the above-identified problems with photoacoustic spectrometers by providing a compact and efficient solid state laser system to drive a PPLN crystal in an OPO.
[0013] It is one aspect of the present invention to provide photoacoustic spectrometers that is portable and rugged for use in the field.
[0014] It is another aspect of the present invention to provide a photoacoustic spectrometer that can speciate mixtures of volatile organic compounds.
[0015] It is one aspect of the present invention to provide a photoacoustic spectrometer for analyzing a sample including a light source, a photoacoustic cell, and a controller, where the light source has a laser and an OPO for generating a beam of an adjustable wavelength light from the laser. The OPO has a light path and a material with non-linear optical properties within the light path, a first tuner to vary the adjustable wavelength by modifying said non-linear optical properties within the light path, and a second tuner to vary said adjustable wavelength by modifying the oscillating frequency of the OPO. The photoacoustic cell is adapted to contain the sample and has at least one window to accept the generated beam and irradiate a sample, and a pressure transducer adapted to provide an indication of the pressure of the sample; and a controller to scan said adjustable wavelength. In one embodiment, the non-linear material is a PPLN crystal.
[0016] It is another aspect of the present invention to provide a photoacoustic spectrometer that has a light source that includes an Yb-fiber pumped OPO having a PPLN crystal, where the OPO is finely tuned by continuous or mode-hopped tuning of the OPO cavity and is coarsely tuned by moving a fan-shaped PPLN crystal in the optical cavity of the OPO.
[0017] It is yet another aspect of the present invention to provide a photoacoustic spectrometer for analyzing a sample including a light source, a photoacoustic cell, and a controller, where the light source has a laser system including a laser and an optical-fiber amplifier adapted to amplify light from said laser, and an OPO having a non-linear optical material for generating a beam of an adjustable wavelength light from said amplified laser. The photoacoustic cell is adapted to contain the sample and has at least one window to accept the generated beam and irradiate a sample, and a pressure transducer adapted to provide an indication of the pressure of the sample; and a controller to scan said adjustable wavelength.
[0018] It is an aspect of the present invention to provide a photoacoustic spectrometer that has a light source that includes a neodymium-yttrium aluminum garnet (Nd:YAG) laser, amplified by a Yb-fiber amplifier, to drive an OPO having a PPLN crystal, where the OPO is finely tuned by continuous or mode-hopped tuning of the OPO cavity and is coarsely tuned by moving a fan-shaped PPLN crystal in the OPO cavity.
[0019] It is yet another aspect of the present invention to provide a photoacoustic spectrometer for analyzing a sample including a light source, a photoacoustic cell, and a controller, where the light source has a laser system with a laser having a wavelength adjustable output that is adjustable within the range from approximately 750 to approximately 900 nm. The amplifier output is provided to an OPO for generating a beam of an adjustable wavelength light from the amplified laser, which has a fixed light path and a fixed non-linear material. The spectrometer also includes a photoacoustic cell to contain a sample and has at least one window to accept said generated beam and irradiate a sample, and a pressure transducer adapted to provide an indication of the pressure of the sample. A controller is provided to control the wavelength of the pump laser.
[0020] A further understanding of the invention can be had from the detailed discussion of the specific embodiment below. For purposes of clarity, this discussion refers to devices, methods, and concepts in terms of specific examples. However, the method of the present invention may be used to connect a wide variety of types of devices. It is therefore intended that the invention not be limited by the discussion of specific embodiments.
[0021] Additional objects, advantages, aspects and features of the present invention will become apparent from the description of preferred embodiment set forth below.
BRIEF DESCRIPTION OF THE DRAWING
[0022] The foregoing aspects and the attendant advantages of the present invention will become more readily appreciated by reference to the following detailed description, when taken in conjunction with the accompanying drawings, wherein:
[0023] [0023]FIG. 1 is a comparison of the absorption spectra for (a) toluene (a large molecule) and (b) NO 2 (a small molecule);
[0024] [0024]FIG. 2 is a schematic of an embodiment of the photoacoustic spectrometer of the present invention;
[0025] [0025]FIG. 3 is an optical layout of a preferred embodiment photoacoustic spectrometer of the present invention;
[0026] FIGS. 4 A-C are optical layouts of OPO embodiments, where FIG. 4A is an optical layout of a preferred OPO embodiment having one coarse tuning mechanism that uses a non-linear material and two fine tuning mechanisms, one that uses an etalon and one that translates a mirror of the OPO cavity; FIG. 4B is an optical layout of another preferred OPO embodiment having one coarse tuning mechanism that uses a non-linear material and one fine tuning mechanisms that uses an etalon; and FIG. 4C is an optical layout of another embodiment having one course tuning mechanism that uses a non-linear material and one fine tuning mechanisms that translates a mirror of the OPO cavity;
[0027] [0027]FIG. 5 is a perspective view of a periodically poled lithium niobate nonlinear material of the preferred embodiment;
[0028] [0028]FIG. 6 is a schematic diagram of the doped-fiber amplifier of the preferred embodiment;
[0029] [0029]FIGS. 7A and 7B are schematic diagrams of an air-spaced etalon of the preferred embodiment and a solid rotating etalon of the preferred embodiment, respectively;
[0030] [0030]FIG. 8 is a graph showing the sensitivity of the preferred embodiment photoacoustic spectroscopy cell for ethane and pentane using an unamplified, 6 W, SLM, 1.06 μm Nd:Vanadate laser manufactured by Coherent Inc (5100 Patrick Henry Drive, Santa Clara, Calif. 95054)(the “Coherent light source”);
[0031] [0031]FIG. 9 is a graph of the photoacoustic spectrum of the methane Q branch as obtained with the preferred embodiment OPO pumped with the Coherent light source and the theoretical spectrum;
[0032] [0032]FIG. 10 is a graph showing the scanning characteristics of an air-spaced etalon as the output wavelength of beam as a function of the etalon displacement;
[0033] [0033]FIG. 11 is an alternative embodiment laser system and OPO; and
[0034] [0034]FIG. 12 is a side view of a PPLN crystal in an oven.
[0035] Reference symbols are used in the Figures to indicate certain components, aspects or features shown therein, with reference symbols common to more than one Figure indicating like components, aspects or features shown therein.
DETAILED DESCRIPTION OF THE INVENTION
[0036] The present invention will now be described with reference to the Figures. The description that follows will first describe several embodiments of the photoacoustic spectrometer of the present invention, and is followed with detailed descriptions of the OPO and of the tuning of the OPO. A description of cell calibration and data acquisition are then presented, followed by alternative embodiments.
[0037] [0037]FIG. 2 is a schematic of an embodiment of a photoacoustic spectrometer 200 of the present invention. Photoacoustic spectrometer 200 includes a tunable light source 210 , a photoacoustic cell 260 adapted for receiving a gas sample and accepting light from the light source, and a control and data acquisition system 270 . The gas sample is admitted into cell 260 from a source G that can be from the environment or from a sampling container, and can be admitted either continuously or as a fixed volume. Cell 260 has windows (not shown) that allow for the transmission of light beam D into the gas sample and a pressure transducer or microphone (not shown) to monitor variations in the pressure P of the sample.
[0038] Light source 210 produces a beam D of light having a narrow spectral distribution about a tunable wavelength λ D , and provides the light to the sample within cell 260 with intensity I. Wavelength λ D of beam D is adjustable and, preferably, is capable of being modulated so that the intensity I of beam D may be pulsed. In one embodiment, the inventive spectrometer provides for fine tuning of light source 210 , with steps of less than 0.1 cm −1 over a broad spectral range of from approximately 100 cm −1 to approximately 300 cm −1 or more.
[0039] System 270 sends control signals S λ and receives signals S data from light source 210 and cell 260 to control light source 210 , and obtain data from the light source and cell 260 . Specifically, system 270 controls, through signal S λ , the wavelength λ D , and receives information regarding the intensity I and pressure P as signals S data . System 270 can include a computer having appropriate interfaces for sending and receiving signals as well as specialized data acquisition components, such as lock-in amplifiers, and controllers, such a stepper motor controllers for adjusting experimental parameters such as laser wavelength, power or control gas into out of cell 260 , and data analysis and display devices.
[0040] Unlike prior art photoacoustic spectrometers, photoacoustic spectrometer 200 is small, efficient, and has a low power consumption rate. As such, spectrometer 200 can be provided in a self-contained package that is portable and rugged enough for field use. Spectrometer 200 thus also includes one or more batteries 210 to power the spectrometer, including but not limited to light source 210 and system 270 .
[0041] The photoacoustic spectrum of a sample is determined by measuring pressure waves in a contained sample as a function of the wavelength of absorbing light as follows. Absorption of light of wavelength λ D by the gas in cell 260 both locally and nearly instantaneously raises the temperature of the absorbing gas, and is quickly converted into a localized pressure increase. When beam D is pulsed, the absorption of light results is thus converted into localized pressure pulses in the gas. As the wavelength XD is varied, pressure pulses are generated that have an amplitude that varies with the absorption coefficient of the sample.
[0042] In general, photoacoustic cell 260 has the following characteristics that result in a spectrometer that is well-suited for use in the field. The size of spectrometer 200 is decreased and the sensitivity in increased by amplifying the laser-induced pressure oscillations. Acoustic amplification of laser-induced pressure oscillations are provided by having a photoacoustic cell that is acoustically resonant at a modulation frequency of the laser, and that allows access of the laser to regions in the cell where the pressure oscillations are greatest. In some instances there is an interaction of the laser light with the photoacoustic cell windows through which it passes. Acoustic disturbances from this interaction are reduced by isolating the resonant chamber from the windows with a cell cavity enlargement near the windows. A large photoacoustic cell mass is also desirable to dampen external acoustic noise. Also, rapid analysis of samples is facilitated by having a photoacoustic cell volume that is small, permitting rapid exchange of the gas volume.
[0043] Acoustic amplification of the pressure oscillations in photoacoustic cell 260 results from the interaction of beam D and the gas contained within cell 260 . The gas contained in cell 260 has numerous acoustic modes at which it can resonate. These acoustic modes are determined by shape standing acoustic waves in the volume of gas in cell 260 . For example, a cylindrical volume of finite length can support an infinite number of discrete modes combining pressure distributions in the shape of radially dependent Bessel's functions and longitudinal sine or cosine waves. The lowest radial and longitudinal frequency modes have periodic pressure waves whose amplitude varies monotonically from the center to the edge of the cylinder. The acoustic oscillation frequency of the individual modes is proportional to the speed of sound of the gas in cell 260 . The sound speed is a thermodynamic property of the gas that depends on the gas constituents, pressure and temperature.
[0044] When the pulsing of beam D occurs at the frequency of an acoustic mode of the gas in cell 260 , and when the absorbed energy is deposited in time with the oscillations such that energy is locally deposited near pressure maximums, the energy of the absorbed light is then acoustically coupled to the resonating gas, amplifying the pressure waves. This amplification of pressure waves through this process is analogous to the timed pushing of a pendulum, where the pushes are timed to the oscillation of the pendulum and the energy input occurs when the potential energy is greatest.
[0045] The proper timing of the position and pulsation frequency of beam D thus increases the pressure oscillations for a given amount of light absorption, effectively increasing the sensitivity of the spectrometer. Acoustic amplification by a factor, Q, of greater than 100 is possible, increasing the sensitivity of the photoacoustic spectrometer. Acoustic amplification is exploited by varying the intensity I between a high value and low value, preferably zero. Measurements of P and λ D can then be used by processor 270 , or are transmitted to another system to determine the photoacoustic spectra, P(λ D ). It is known that the pressure P increases linearly with the intensity I, and thus the intensity I can be used to normalize by the pressure P to obtain intensity independent spectra, P′(λ D )=P(λ D )/I(λ D ).
[0046] [0046]FIG. 3 shows a preferred embodiment of a photoacoustic spectrometer 300 . Photoacoustic spectrometer 300 includes a tunable light source 310 that is capable of generating a periodically modulated light beam D of adjustable wavelength to probe a sample of gas G in a photoacoustic cell 360 . Spectrometer 300 also includes a control and data acquisition system 370 that controls and/or monitors light source 310 and acquires a photoacoustic spectrum of sample G.
[0047] Light source 310 has optical and mechanical elements that cooperatively adjust the wavelength λ D of light beam D and provides light beam D to cell 360 . Specifically, light source 310 includes a laser system 320 , an OPO 330 , a modulator 311 , and a reflector 317 . Light source 310 also includes a beam splitter 313 , a lens 314 , and a light detector 315 that are used maintain the intensity of beam D.
[0048] As shown in FIG. 6, laser system 320 includes a laser 321 , a Faraday isolator 323 , an optical-fiber amplifier 325 , and a fiber port 329 . In one embodiment, laser 321 is a cw diode seed laser, such as an Nd-based laser, having a narrow spectral output in the mid-IR of several to a few hundred milliwatts and a linewidth of less than about 100 MHz.
[0049] Light from laser 321 is amplified by optical-fiber amplifier (OFA) 325 which includes a doped fiber 326 , and one or more pump lasers 327 that are each coupled to fiber 326 through coupling fibers 328 . Faraday isolator 323 is provided between laser 321 and optical-fiber amplifier 325 to isolate the laser from upstream reflections. OFA 325 is similar to doped fiber amplifiers that are known and used in the telecommunications industry, such as an erbium-doped fiber amplifier. It is preferred that fiber 326 is an Ytterbium (Yb) doped fiber, as this type of fiber amplifier is well-suited to amplifying light at 1.06 μm. Pump laser 327 supplies light at 980 nm and is mixed with the output of laser 321 , causing the incident light at 1.06 μm to be amplified within fiber 326 . The amplified laser output in fiber 326 passes from OFA 325 through fiber port 329 as beam A with sufficient power for use by OPO 330 to generate beam B. In a preferred embodiment, laser 321 is an Nd:YAG laser that is amplified by Yb-doped OFA 325 to a power of from 4 to 6 watts at λ A =1.06 μm. In a particularly preferred embodiment, laser 321 has a power of about 50 to about 100 milliwatts.
[0050] OPO 330 includes one or more non-linear elements that accept light of one wavelength (beam A of wavelength λ A ) and can tunably generate light of two different wavelengths. In general, optical parametric oscillators operate more stably in a continuous mode and at a single wavelength, and thus it is preferred that laser 321 is a continuous wave (cw) laser that oscillates in a single-longitudinal-mode (SLM), and that OPO 330 be singly resonant.
[0051] The selection of a laser 321 and an OFA 325 is governed by the necessity to efficiently generate a pump beam A that is both spectrally narrow and has sufficient power to induce non-linear light generation in OPO 330 at low cost. The specifications on wavelength and power are to be understood in conjunction with the operation of the OPO. Since the amount of power required to generate beam B will depend on wavelength λ A , different combinations of lasers and amplifiers are within the scope of the present invention. For example, optical-fiber amplifiers contain different dopants depending on wavelength λ A , and the amount of power required to drive the non-linear material of the OPO decreases with decreasing wavelength λ A . For example, 1.55 μm light is best amplified with an erbium-doped fiber amplifier, but such systems require higher powers to operate an OPO.
[0052] The combination of laser 321 and OFA 325 thus has several features that make it advantageous for use in photoacoustic spectrometers and particularly advantageous for use in a field portable photoacoustic spectrometer. First, the amount of power required to operate preferred laser system 320 is much less than that required for operating an Nd:Vanadate laser having similar output characteristics. An Nd:Vanadate laser having 6 W of output power at 1.06 consumes only approximately 60 W of electrical power. The reduced power consumption allows for use of battery power for the various lasers, as well as the data acquisition and control system and ancillary electronics. Further, the preferred laser system is much less expensive than prior art systems. For example, currently the cost of a 6 W Nd:Vanadate laser is $70,000, while the combined Nd:YAG/Yb-doped fiber amplifier having 6 W of output power costs $20,000. Third, the inventive system is easily tunable. This allows for tuning the wavelength of the light source through tuning of laser 321 , or OPO 330 , or a combination thereof. Laser tuning allows use of more advanced techniques for acquiring photoacoustic spectra, such as by dithering the excitation frequency to provide differencing measurements.
[0053] After exiting OPO 330 , beam B is periodically interrupted by modulator 311 to produce periodic beam D at a wavelength λ D that is the same wavelength as beam B (λ D =λ B ). Modulator 311 also generates a data signal S ref that provides a chopping frequency reference that is useful for data analysis. In one embodiment, modulator 311 includes a rotating disk that periodically allows beam B to pass through, thus generating a periodic beam D according to the rotation rate of the disk and the pattern of openings on the disk. Alternatively, modulator 311 could be a rotating prism or a solid state device, such as an acousto-optic modulator.
[0054] The intensity of beam D is monitored by extracting a small portion of the beam with beam splitter 313 , though lens 314 , to light detector 315 . It is preferable that beam D is monitored by sampling a small portion of the beam, such as 1-5% of the incident beam. Lens 314 tightly focuses the sampled light onto the face of detector 315 , which responds to the temporal variation of the intensity I of beam D by generating a data signal S I . Infrared detectors, such as detector 315 are well known in the art. It is preferred that detector 315 has a flat spectral response over the spectral range of beam D and that there are no windows to cause etaloning of the sampled beam. A preferred brand of detector is a pyrometer manufactured by Molectron Detector, Inc. (7470 SW Bridgeport Road, Portland, Oreg. 97224) with a detector area of approximately 5 mm 2 .
[0055] The portion of beam D that passes undeflected by beam splitter 313 continues onto cell 360 and is reflected back towards the cell by reflector 317 , resulting in a double-pass through the sample gas.
[0056] Photoacoustic cell 360 accepts a sample G and has a pressure transducer 365 that produces a pressure-level proportional signal S P . In one embodiment, transducer 365 is a hearing aid microphone. The pressure levels generated in cell 360 when determining the photoacoustic spectra are typically acoustic waves at a frequency on the order of about 1 kHz. The measurement of acoustic pressures is well known in the art, and there are many pressure transducers that are capable of accurately measuring these pressures.
[0057] Signal S P , which is indicative of the pressure of the sample in cell 360 depends on a number of factors: the overlap of the laser beam and those areas of the acoustic mode having large pressure oscillations, the intensity of the laser beam, the excitation or chopping frequency, the volume and acoustic amplification, Q, of the cell and the absorption properties of the gas. While a large Q would appear to be desirable, it was found that such a cell is also prone to picking up background noise and is sensitive to environmental factors, such as changes in temperature. After testing several cells, it was found that a cell with a Q of about 10 produced good photoacoustic sensitivity and low noise. As an example of such a cell is shown schematically in FIG. 3. Specifically, cell 360 has a cylindrical volume 361 , a pair of acoustic filters 367 at the cylinder ends, and a window 363 near each filter. Windows 363 are transparent to beam D, and can be manufactured, for example, from ZnSe tilted at Brewster's angle to reduce reflection losses and to avoid stray reflections which could raise the acoustic background level.
[0058] One cylindrical volume 361 that was found to produce good results when illuminated by the Coherent light source has a length of 15 cm and a diameter of 9 mm, resulting in a lowest acoustic resonance frequency corresponding to the first longitudinal acoustic mode. This volume has an oscillation frequency, when filled with an atmospheric sample, of approximately 1,600 Hz. The small volume allows for quick gas exchange and thus quick data acquisition. Acoustic filters 367 are enlarged cavity volumes that acoustically dampen noise generated by absorption of the laser beam at the surface of the windows from reaching transducer 365 . Cell 360 has a lowest frequency mode with pressure waves that vary sinusoidal in time and that have a peak pressure along the cylinder centerline. Acoustic coupling of light absorption of a wavelength λ D into a cylindrical sample can thus be accomplished by pulsing beam D along the cylinder centerline at a frequency corresponding to that acoustic mode.
[0059] Windows 363 and volume 361 are aligned with beam D, including reflector 317 , to provide a double pass of beam D through cell 360 . Since only a small portion of beam D is absorbed by the sample in cell 360 , the amount of energy absorbed by the sample, and thus the pressure P, increases with the number of passes of light through the cell. However, it has been found that each pass through cell 360 also increases the noise in signal Sp due to scattering at the windows. For configurations with more than two passes, an off-axis beam geometry is required that makes is more difficult to aim the beam through the cell. The effects, coupled with beam profile changes that were observed with etalon mode hops, produced a noticeable modulation in the photoacoustic signal when more than two passes were used. Although filters 367 reduce the amount of noise, it is preferred that a two-pass configuration be used to increase the signal S P without unduly increasing the complexity of the cell or increase noise in the system.
[0060] The sensitivity of cell 360 as determined for ethane and pentane using the Coherent light source is shown in FIG. 8. The measurements shown in FIG. 8 were made with the sample gas diluted in pure nitrogen and at atmospheric pressure, and indicate extrapolated sensitivities of approximately 15 ppb for ethane, and approximately 22 ppb for pentane. Cell 360 is thus seen to have the sensitivity required to detect small quantities of organic compounds.
[0061] System 370 preferably includes processor 373 , an amplifier 371 that is preferably a lock-in amplifier, and a display unit 375 . Processor 373 controls the adjustment of wavelength λ B . Amplifier 371 receives reference signal S ref , intensity signal S I , and pressure signal S P , and effectively amplifies those components of the intensity and pressure having a component occurring at the chopping frequency. In one embodiment, amplifier 371 includes two separate lock-in amplifiers, one amplifier which accepts reference signal S ref and intensity signal S I , and the other amplifier accepts reference signal S ref and pressure signal S P .
[0062] Display unit 375 receives wavelength, pressure and intensity information that is used to generate a visual display of the photoacoustic spectra. Preferably, amplifier 371 provides a normalized pressure output to display unit 375 , such as the ratio of the pressure to intensity.
[0063] Optical Parametric Oscillator
[0064] FIGS. 4 A-C are optical layouts three preferred embodiments of OPO 330 , shown an OPO 330 ′, and OPO 330 ″, and an OPO 330 ′″, respectively. The embodiments of FIG. 4 differ according by their fine tuning mechanisms. FIG. 4A is an optical layout of a preferred embodiment of OPO 330 ′ having one coarse tuning mechanism that uses a non-linear material and two fine tuning mechanisms as described below, one that uses an etalon and one that translates a mirror of the OPO cavity. FIGS. 4B and 4C each have the same general optical layout as OPO 330 ′, but each has only one of the fine tuning mechanisms of OPO 330 ′. Specifically, FIG. 4B is an optical layout showing the fine tuning portion of OPO 330 ″ that uses an etalon; and FIG. 4C is an optical layout showing the fine tuning portion of OPO 330 ′″ that translates a mirror of the OPO cavity. The following discussion of FIG. 4A thus applies to the embodiments of FIGS. 4B and 4C with respect to their respective tuning mechanism.
[0065] [0065]FIG. 4A shows a schematic of a preferred embodiment an OPO system 330 ′, which accepts beam A from laser system 320 , oscillates a beam C, and provides an output beam B. OPO 330 includes a pair of plano-concave mirrors 331 and 337 , a pair of planar mirrors 339 and 343 , a non-linear optical material 333 , an intra-cavity etalon 341 , a first beam splitter 347 , a diagnostic etalon 349 , a second beam splitter 351 , a beam dump 353 , and a lens 355 .
[0066] Mirrors 331 , 337 , 339 , and 343 form an optical cavity, as shown by the path of beam C. Beams A and B pass out of the optical cavity through mirror 337 . Preferably, a small portion of beam B is sampled by beam splitter 347 to diagnostic etalon 349 to monitor the wavelength of beam A, and the remaining beam A is separated by beam splitter 351 into beam dump 353 , allowing beam B to exit OPO 330 after being collimated by lens 355 . OPO 330 also includes a coarse tuning mechanism and at least one fine tuning mechanism, described subsequently.
[0067] As described subsequently, non-linear optical material 333 interacts with a beam A to generate a beam B and a beam C. Specifically, non-linear material 333 within the path of beam A generates two coaxial beams: a beam B having a wavelength λ A and beam C. (These beams are shown schematically in FIG. 3 as being laterally displaced.) Beams A, B, and C are reflected and/or transmitted by planar mirrors 339 and 343 and mirrors 331 and 337 , along with concave surfaces 331 a and 337 a of respectively, as follows. Mirrors 331 and 337 have high transmissivities for the wavelength range of beam A, allowing beam A to substantially pass once through OPO 330 . Mirror 337 also has a high transmissivity for the wavelength range of beam B, allowing beam B to substantially exit OPO 330 after being generated by non-linear optical material 333 . Planar mirrors 339 and 343 and mirrors 331 and 337 are highly reflectivity at the wavelength range of beam C. The high reflectivity of mirrors 339 , 343 , 331 , and 337 and the curvature of concave surfaces 331 a and 337 a allow a substantial portion of beam C to recirculate through OPO 330 , in a “bow-tie” configuration, and in particular to make multiple passes through non-linear optical material 333 .
[0068] The “bow-tie” configuration of OPO 330 provides better frequency stability, single mode operation and more space for intra-cavity tuning elements than other configurations. Specifically, the geometry of OPO 330 supports single mode or single frequency operation, without intra-cavity tuning elements. This is not the case with linear resonators, which suffer from random mode hopping and multi-mode operation.
[0069] In one embodiment of OPO 330 , curved surfaces 331 a and 337 a have a radius of curvature of 10 cm with non-linear optical material 333 centered between mirrors 331 and 337 and mirrors 339 and 343 . An example of acceptable coatings for beam A wavelength of 1.064 μm, beam B wavelength of 3.3 μm, and beam C wavelength of 1.57 μm is as follows. Mirrors 331 and 337 are coated on both sides for high transmission (>98%) of the beam A at 1.064 μm and for high reflectivity (>99.5%) on the curved surfaces for beam C at 1.57 μm. The reflectivity of mirror 337 at the wavelength range of beam B (3.3 μm) is as low as possible (<10% for curved surfaces 331 a and 337 a and <0.1% for planar mirrors 339 and 343 ) to couple as much 3.3 μm light out of the cavity of OPO 330 as possible and to avoid feedback from beam C, since feedback of 10 −4 or greater per roundtrip can result in double resonance. OPO 330 thus supports resonating beam C and allows beams A and B to pass through mirror 337 .
[0070] Since the spectra of beam B is a function of the spectra of beam A, it is preferable to operate laser 321 in a single-longitudinal-mode to achieve single frequency operation of OPO 330 . In general, a multi-mode laser 321 could be used if the idler wave (beam B) were resonated inside the OPO cavity instead of the signal wave (beam C). However, this is difficult due to mirror coating considerations. Beam A is focused to approximately 100 μm in intensity diameter inside the PPLN crystal. The oscillation threshold of OPO 330 operated as a cw, singly resonant OPO is approximately 3 watts and when pumped at 6.5 watts, the OPO depletes beam A by 85-90%.
[0071] [0071]FIG. 5 shows a preferred non-linear material 333 as a periodically poled lithium niobate (PPLN) crystal 533 that converts beam A into beams B and C. Beam A drives the non-linear material 333 , and is usually called the “pump beam.” The two output beams have different photon energies (wavelengths). Beam B has the lower photon energy (longer wavelength), and is commonly called the “idler beam,” and beam C has the higher photon energy (shorter wavelength), and is commonly called the “signal beam.” The wavelengths of the signal and idler beams are adjustable according to the nonlinearities of the non-linear material and the resonant modes of the cavity, as well as the wavelength of the pump beam. The energy of the generated beams B and C equals the energy of the converted portion of beam A, and the sum of the frequency of beams B and C equals the frequency of beam A.
[0072] PPLN crystal 533 is used to tunably convert light from beam A into beam B over a wavelength range that is useful for spectroscopic measurements of organic compounds. One embodiment PPLN crystal 553 is the fan-type crystal shown in FIG. 5, and described in U.S. Pat. No. 6,359,914 and incorporated herein by reference. The preferred embodiment PPLN crystal 533 has the following dimensions along the x, y, and z axis, respectfully: 50 mm long, 20 mm wide, and 0.5 mm thick. Crystal 533 has a 1° wedge between the input and output facets (the faces perpendicular to the x axis) to help eliminate idler feedback in OPO 330 . The faces of PPLN crystal 533 have anti-reflection coatings at both 1.064 μm and at 1.57 μm. PPLN crystal 533 has a theoretical tuning range of about 350 cm −1 at 180° C., and can convert pump beam A having a wavelength λ A of 1.06 μm into a signal beam (beam C) having a wavelength λ C that is adjustable from 1.53 to 1.62 μm and an idler beam (beam B) having a wavelength λ B that is related to wavelength λ B and is adjustable from 3.1 to 3.5 μm.
[0073] The temperature of PPLN crystal 533 is controlled as shown in FIG. 12, which shows the PPLN crystal in an oven 1200 having an upper portion 1201 , an upper portion heater 1205 , a lower portion 1203 , and a lower portion heater 1207 . The two planes of PPLN crystal 533 bound by surfaces parallel to the x-y plane, shown in FIG. 5, are in thermal contact with portions 1201 and 1203 , respectively. Oven 1200 also includes a temperature sensor 1209 and a control system 1215 . Control system 1215 receives oven temperature information from sensor 1209 through an electric connection 1211 and provides power to heaters 1205 and 1207 through connections 1213 . It is preferred that portions 1201 and 1203 are highly thermally conductive materials, such as copper, and that heaters 1205 and 1207 are electric resistance heaters. Control system 1215 is instructed to maintain a prescribed temperature of crystal 533 and supplies power accordingly to heaters 1205 and 1207 to maintain this temperature. temperature. While it is preferred that control system 1215 is a stand-alone system with a non-changing prescribed temperature, control system 1215 is alternatively a controller programmed by 370 .
[0074] The prescribed temperature must meet two requirements. First, the optical properties of PPLN crystal 533 are temperature dependent, with thermally-induced changes in the refractive index having a large impact on the wavelengths λ B and λ C To maintain control of the wavelengths of light generated by crystal 533 to the degree required for detailed spectroscopic analysis, the prescribed temperature should be maintained to within 0.01° C. Second, PPLN crystals are known to suffer from photorefractive damage. This damage is mitigated by heating the PPLN crystal 533 to a temperature high enough to allow the crystal to anneal. It is believed that a prescribed temperature of 180° C. is sufficient to anneal the crystal, though other temperatures may achieve the same effect. It is preferred that oven 1200 maintain the temperature of PPLN crystal 533 to 180.0±0.1° C.
[0075] Three axes of crystal 533 are shown in FIG. 5 as x, y, and z. The optical properties of crystal 533 are constant in the z direction, and are periodic for a beam propagating perpendicular to the z axis. Specifically, crystal 533 has periodic properties that depend on the y position, with periods that vary from Λ=29.3 to Λ=30.1 μm at increasing values of y. Incident beam A is thus subject to periodically changing optical properties as it propagates through crystal 533 in the x direction It is important that the polarization of beam A, as indicated in FIG. 5, is aligned in the z-direction to undergo conversion of similarly polarized beams B and C in crystal 533 .
[0076] PPLN crystal 553 , and in particular the period of the crystal, can be adjusted by moving the crystal along the y-axis and relative to pump beam A, producing non-linear interactions that generate two beams of different wavelengths that vary as a function of the position of the crystal along the y-axis. The use of a fan-type crystal for coarse tuning of OPO is described below.
[0077] While the previous description refers to pumping OPO 330 from laser system 320 , the combined coarse and fine tuning capabilities of OPO 330 can produce tunable output using other pumping lasers or laser systems having sufficient output and at a proper wavelength to enable the OPO to generate beam B. Thus, for example, beam A of FIGS. 4 A- 4 C can be a beam from a different light source with 1 μ output having that is spectrally narrow and has an output in the watt range that is polarized as previously described with respect to the PPLN crystal.
[0078] Tuning the Optical Parametric Oscillator
[0079] Preferred OPO 330 combines coarse tuning and fine tuning to scan a large range of wavelength λ B with high resolution. Coarse and fine tuning are individually and collectively controlled by processor 373 to scan wavelength λ B through the combined commands of control signals controls S λ coarse and S λ fine , respectively. One scanning technique is to repeatedly scan the fine tuning range while the coarse tuning range is increased stepwise at the beginning of each fine tuning range. The fine tuning can be either continuous or discrete depending on the technique used, as described below. Non-monotonic scanning can be corrected by sorting the spectra according to a measurement of wavelength λ B .
[0080] In general, preferred coarse tuning for OPO 330 is accomplished through changes to the non-linear material 333 within the optical cavity in response to a control signal S λ coarse . Preferred fine tuning alters the optical cavity of OPO 330 through one or both of the following techniques. The first alters the optical cavity in response to a control signal S λ fine−1 by adjusting elements within the cavity (such as etalon 341 ), allowing the oscillations to jump from one mode to another. This results in discrete changes in the output wavelength during tuning and is termed “mode-hop” tuning. The second alters the optical cavity in response to a control signal S λ fine−2 by increasing or decreasing the cavity length through the movement of mirror 343 , allowing the oscillating frequency can adjust accordingly, and is termed “continuous” tuning. FIG. 4A shows OPO 330 ′ with coarse tuning and two fine tuning mechanisms-mode hop tuning using etalon 341 and continuous tuning through the translation of mirror 343 . FIG. 4B shows details of the fine tuning mechanism of OPO 330 ″ using only mode hop fine tuning by etalon 341 . FIG. 4C shows details of the fine tuning mechanism of OPO 330 ′″ using only continuous fine tuning by translation of mirror 343 . The coarse and fine tuning techniques are described subsequently.
[0081] Coarse tuning through the movement of crystal 533 is achieved as follows. As noted above, crystal 553 is aligned for propagation of pump beam A along the x-axis, with periods varying along the y-axis from Λ=29.3 to Λ=30.1 μm. PPLN crystal 553 , and in particular the period of the crystal, can be adjusted by moving the crystal along the y-axis and relative to pump beam A, producing non-linear interactions that generate two beams of different wavelengths that vary as a function of the position of the crystal along the y-axis. Coarse tuning using the fan-shaped PPLN crystal 533 is accomplished by moving the crystal in the “y” direction shown in FIG. 5 by first translator 335 in response to control signal S λ coarse . Translator 335 can be a stepper motor or any other mechanism for repeatably and controllably translating crystal 533 . PPLN crystal 533 has a theoretical tuning range of about 350 cm −1 at 180° C., and can convert pump beam A having a wavelength λ A of 1.06 μm into a signal beam (beam C) having a wavelength λ C that is adjustable from 1.53 to 1.62 μm and an idler beam (beam B) having a wavelength λ B that is related to wavelength λ B and is adjustable from 3.1 to 3.5 μm. Translating crystal 533 approximately 0.04 mm moves the OPO gain peak approximately 4 cm −1 .
[0082] In fine mode-hop tuning, an etalon 341 in the optical cavity alters the effective length of the optical of OPO 330 by adjusting the spacing of the etalon with a motor controlled by signal S λfine−1 . Although the etalon may be continuously varied, the optical cavity of the OPO prefers to oscillate at discrete frequencies, and changes in etalon 341 result in discrete changes in the tuned frequency of the OPO. For the embodiment of FIGS. 4A and 4B, etalon 341 provides fine-frequency steps on the order of 0.6 to 1.2 GHz. The longitudinal mode spacing of OPO 330 is on the order of approximately 570 MHz, and thus the frequency changes during mode hoping correspond to 1 to 2 cavity modes. Uncontrollable perturbations of the OPO can result in mode hopping, and thus it can be difficult to achieve control of the mode hops to within a mode or two.
[0083] Since OPO 330 tends to oscillate in a single mode without intra-cavity elements, etalon 341 has to constrain only the oscillating mode, which allows the use of weakly frequency selective (or “low-finesse”), low-loss etalons. This is important since the OPO can only tolerate cavity losses on the order of 5% or less. Although fine tuning has been demonstrated in many laser systems, there are some subtle yet important differences in both OPO tuning and in the use of PPLN.
[0084] Several types of etalons 341 can be used as in inter-cavity etalon with an OPO as shown in FIGS. 4A and 4B, for example, the etalon can be either an air-spaced etalon 341 ′, as shown in FIG. 7A, or a rotating solid etalon 341 ″, as shown in FIG. 7B. It is important that the reflectivity or spectral rejection of the etalon be quite low—on the order of a few percent or so, since there is a tradeoff between reflectivity and required pump power.
[0085] Rotating solid etalon 341 ″ includes a solid etalon material 711 and rotation stage (not shown) that rotates material 711 through an angle γ in the plane of FIG. 7B in response to control signal S″ λ fine−1 , as indicated by arrow 713 . Rotation through an angle γ of a few degrees with etalon 341 ″ in the path of beam C tunes OPO 330 ′ or 330 ″ over a few wavenumbers. A preferred rotating solid etalon 341 ″ is a 400 μm thick, uncoated YAG substrate. Measurements using the Coherent light source with OPO 330 indicate that this etalon gives the best combination of mode hop step size, tuning range (several hundred wave numbers), and power (approximately 120 mW maximum in the idler), with a pump depletion typically in the range of 40-50% for 6 W of pump power. Although the rotation is nearly continuous, the frequency steps are discrete on the order of 0.02-0.1 cm −1 , depending on the number of cavity modes jumped. Various performance factors limit the solid etalon mode-hop tuning to the range of approximately 4 cm −1 .
[0086] To illustrate the use of a mode-hop-tuned PPLN OPO in spectroscopic applications, FIG. 9 shows the photoacoustic spectrum of the methane Q branch as obtained with OPO 330 pumped with the Coherent light source, along with the theoretical spectrum. This spectrum was acquired at atmospheric pressure where pressure broadening is large. The scan of FIG. 9 was acquired by simultaneously tuning the PPLN crystal 533 combined with rotation of the solid etalon 341 ″. Approximately four etalon scans were necessary to cover the 10 cm −1 spanned by the methane Q branch, resulting in a broad and finely resolved spectrum.
[0087] There are several drawbacks however, of using a rotating solid etalon. First, the scan rate depends nonlinearly (quadratically) on etalon angle which requires software to linearize the scan and furthermore, the intra-cavity loss also depends nonlinearly with angle.
[0088] Air-spaced etalon 341 ′ overcomes some of the problems encountered with solid etalons by having a constant tuning rate and a constant insertion loss which reduces the possibility of etalon mode hops. Air-spaced etalon 341 ′ is shown in FIG. 7A includes of two wedged fused, UV-grade silica substrates, 701 and 703 . Each substrate has a pair of sides that approximately perpendicular to beam C: a pair 701 a and 701 b , and 703 a and 703 b , respectively. Each pair of sides forms an angle, α, of approximately 30′. Substrates 701 and 703 are oriented with adjacent thick and thin portions, spaced apart by a distance ε of approximately 0.5 to 1.5 mm. One side of each substrate 701 and 703 has a 1.5 μm AR coating, and the other side of each substrate has no coating, yielding a reflectivity of approximately 5% and reducing misalignment. Air-spaced etalon 341 was inserted into OPO 330 at an angle, β, approximately 0.5° off of normal incidence of beam A to avoid optical feedback. A piezoelectric element 705 responds to control signal S λ fine−1 to tune the distance between the substrates of the air-spaced etalon as indicated by arrow 707 . Piezoelectric element 705 is preferably an annular element adapted to tune the etalon spacing over approximately 3 μm, resulting in a tuning range on the order of 10-50 cm −1 , depending on the etalon mirror spacing.
[0089] An example of a scan obtained with the air-spaced etalon is shown in FIG. 10, which shows, in arbitrary units, the output wavelength of beam D as a function of the etalon displacement, 6 , and displays a mode-hop scan over 20 cm −1 obtained with a scanning air-spaced etalon and synchronized with the tuning of crystal 533 . For this scan, the etalon displacement is scanned by approximately 0.1 μm at an average spacing of 1.5 mm, yielding frequency steps on the order of 0.1 cm −1 . Scan non-linearities result, in part, from differential tuning between the etalon transmission peaks and the PPLN gain peak, and also by nonlinearities inherent in the piezo, especially at higher driving voltages. Also, while an air-spaced etalon has the advantage over the solid etalon of a constant insertion loss, the oscillation threshold is somewhat higher (approximately 4 W when pumped with the 6 W Nd:YAG laser), with a corresponding reduced output power (approximately 80 mW of idler power).
[0090] Since both the solid and air-spaced etalons used in OPO 330 are of low finesse, any secondary eltaoning or wavelength-dependent absorption or reflection can influence tuning. These effects include intra-cavity absorption by a gas, such as CO 2 , etaloning in crystal 333 , and mirror reflectivity at 3.3 μm. Thus for example, residual reflectivity of the cavity mirrors at 3.3 μm can cause OPO 330 to become doubly resonant, causing instabilities. Also, idler feedback as small as 10 −4 can affect stability. These effects can be eliminated through better multiband coatings on the flat cavity mirrors.
[0091] For continuous tuning, the cavity length of OPO 330 ′ or OPO 330 ′″ is adjusted by moving mirror 343 with second translator 345 in response to control signal S λ fine−2 . A reliable method of translation on this scale is through the use of piezo-electric transducers 345 . The OPO cavity used a multiple stack piezo-electric transducer which was capable of translations on the order of 40 μm. The effective tuning is twice this since the optical cavity length changes by twice the translation amount. As the cavity length shortened, the cavity modes shift to shorter wavelengths. For OPO 330 ′, etalon 341 is then controlled by a lock-loop to track the peak of a cavity mode as the cavity is tuned. Tuning is accomplished by keeping etalon 341 locked to the cavity mode as the cavity length is tuned.
[0092] There are many perturbations which can disrupt the tuning process, such as air currents inside the cavity caused by the PPLN oven since thermal changes in PPLN crystal 533 can change the effective optical length of the cavity. Some of the perturbations such as convection currents generated by the PPLN oven can be controlled by thermally isolating the oven. Other perturbations, like the rapid thermal fluctuations inside the PPLN crystal (caused in part by absorption of 3 μm light in the crystal) cannot be controlled. If the perturbations occur too rapidly, i.e., outside the bandwidth of the lock loop or if the perturbation was too large then the OPO may uncontrollably mode hop. To keep the insertion losses low the etalon was of relatively low-finesse making the cavity more susceptible to mode hops. The etalon also had to be of low mass so that the loop response frequency is high.
[0093] The application of the continuous tuning methods described herein to tunable OPOs presents many challenges. In particular, although mirror 337 and the mirrors in etalon 341 are designed to transmit at 3.3 μm, there is enough feedback to cause a double resonance effect. Doubly resonant OPOs are in general very unstable. As the cavity length defined by the path of beam C in OPO 330 is tuned, the 1.5 μm light of beam C tunes continuously, whereas the 3.3 μm light of beam B tunes continuously in the opposite direction. To complicate matters, there are occasions when the 3.3 μm light is slightly resonant in the cavity, which raises the intra-cavity 3 μm power. This in turn raises the temperature of crystal 333 which effectively changes the optical length and causes the laser to tune uncontrollably. To mitigate this problem, alternative OPOs have optical components that are more effective in rejecting intra-cavity 3.3 μm light.
[0094] Cell Calibration and Data Acquisition
[0095] To obtain an interpretable photoacoustic spectrum, it is preferable that the pressure signal, S P , is normalized by intensity of the incident light, S I , by dividing the pressure signal by the incident light signal. As noted above, one embodiment includes two separate lock-in amplifiers 371 , one which accepts reference signal S ref and intensity signal S I , and the other accepts reference signal S ref and pressure signal S P . Since the pressure and intensity signals are modulated by a rate given by the reference signal, amplifier 371 can use S ref to obtain an accurate indication of the pressure and intensity. The ratio of the amplified pressure and intensity signals provides an intensity normalized spectral signal. Intensity normalization compensates for intensity fluctuations, but other effects such as detector nonlinearity, detector window etaloning, detector homogeneity, and beam profile changes all can cause residual noise. It has been determined that lens 314 helps to reduce some of these sources of error.
[0096] In general, the sampled gas will contain a mixture of gases having unknown concentration. Obtaining quantitative speciation of a spectrum requires that calibrated photoacoustic spectra be obtained for each species to be identified, preferably at more than one concentration. The following procedures were found to give acceptable results when using light from OPO 330 pumped with the Coherent light source. The cell responsively, R, is required to quantify the raw normalized pressure data. R has units, for example, of μVolts/(C*mW*α), where α is the absorption (1/ppm-m) and C is the concentration in ppm. If the cell is operated at a pressure other than at atmospheric pressure, it is preferable that absolute concentration units. Gases with known absorptions (α's) and concentrations are used to determine the cell responsivity. Under atmospheric conditions the calibration should be independent of the calibration gas since energy transfer from vibration/rotation to translation (heat) is nearly 100%.
[0097] Calibration was obtained for several gases: methyl ethyl ketone, isopropyl acetate, n-butyl acetate and butane. Calibration constants varied from 103 (butane) to over 300 μV-m/mW. There were several reasons for the wide variations; some of the VOCs were slightly polar and therefore stuck to the surfaces of the gas bottle and photoacoustic cell, thus lowering the effective concentration, and second, the absorptions of some of the VOCs were not known accurately. For butane however, which is a nonpolar species, the calculated cell responsivity was from 150-200 μV-m/mW at high concentrations (>50 ppm) but at low concentrations (5 ppm) was reduced to approximately 80. The source of this discrepancy has not yet been determined but we have found variations as large as 20% in the gas dilution system. An adequate approximate calibration constant of 200 μV-m/mW was used in measurements using the Coherent light source for a two pass configuration.
[0098] Alternative Laser Embodiments
[0099] An alternative embodiment laser system and OPO operating near 750 to near 900 nm is shown in FIG. 11. Specifically, FIG. 11 shows a laser source 1220 and an OPO 1230 that are alternatives to laser source 320 and OPO 330 of spectrometer 300 . Laser source 1220 includes a diode seed laser 1221 , a Faraday isolator 1223 , and a tapered waveguide amplifier 1225 . Laser source 1220 generates a beam A′ that is controllable about a wavelength in the range of from 750 to 900 nm according to control signal S λ . Lasers of this type include Ti:sapphire and diode lasers, and are generally tunable over a broad range, such as from 700 to 1000 mm, and can have a narrow band width of 1 MHz.
[0100] OPO 1230 includes a pair of plano-concave mirrors 1231 and 1237 , a pair of planar mirrors 1239 and 1243 , a non-linear optical material 1233 , an etalon 1241 a beam splitter 1251 , a beam dump 1253 , and a lens 1255 . Non-linear optical material 1233 , which can be a PPLN crystal of constant poling frequency, is temperature controlled in a manner similar to crystal 533 , generates a signal beam B′ and an idler beam C′. OPO 1230 is singly resonant at the wavelength of signal beam B′. As the wavelength of beam A′ is varied, the OPO resonates at a fixed signal wavelength and wavelength of idler beam C′ varies according to changes in the pumping wavelength of beam A′. Etalon 1241 can be an air-spaced etalon, similar to etalon 341 ′ or a solid etalon, similar to etalon 341 ″, is used in OPO 1230 to hold the wavelength of signal beam B′ fixed, allowing the wavelength of idler beam C′ to follow the wavelength of pump beam A′. Mirrors 1231 and 1237 are coated on both sides for high transmission (>98%) of the pump beam A′ and for high reflectivity (>99.5%) on the curved surfaces at the wavelength of signal beam B′.
[0101] These operating characteristics make laser 1221 are sufficient to provide sufficient range and controllability to speciate complex organic molecules. In addition, such lasers have greater efficiencies than longer wavelength lasers and can operate an OPO with less power, the total size and efficiency of a photoacoustic spectrometer system operating with a pump laser having a wavelength in the range from 750 to 900 m are reduced over those of a 1 μm laser. In addition, the laser is readily tunable, allowing for tuning of the OPO via changes in the pump wavelength. In such a system the OPO would be singly resonant at a fixed signal frequency and OPO output idler wavelength would follow changes in the pump wavelength. This would eliminate the need for intra-cavity tuning elements within the OPO.
[0102] The invention has now been explained with regard to specific embodiments. Variations on these embodiments and other embodiments may be apparent to those of skill in the art. It is therefore intended that the invention not be limited by the discussion of specific embodiments. It is understood that the examples and embodiments described herein are for illustrative purposes only and that various modifications or changes in light thereof will be suggested to persons skilled in the art and are to be included within the spirit and purview of this application and scope of the appended claims. | The present invention provides a photoacoustic spectrometer that is field portable and capable of speciating complex organic molecules in the gas phase. The spectrometer has a tunable light source that has the ability to resolve the fine structure of these molecules over a large wavelength range. The inventive light source includes an optical parametric oscillator (OPO) having combined fine and coarse tuning. By pumping the OPO with the output from a doped-fiber optical amplifier pumped by a diode seed laser, the inventive spectrometer is able to speciate mixtures having parts per billion of organic compounds, with a light source that has a high efficiency and small size, allowing for portability. In an alternative embodiment, the spectrometer is scanned by controlling the laser wavelength, thus resulting in an even more compact and efficient design. | 6 |
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application is a divisional of U.S. patent application Ser. No. 13/839,238, filed Mar. 15, 2013, which will issue as U.S. Pat. No. 9,528,896 on Dec. 27, 2016, the disclosure of which is hereby incorporated herein in its entirety by this reference.
FIELD
[0002] The present disclosure relates generally to apparatuses and methods for measurement of high pressures under extreme and transient temperature conditions and, more particularly, to quartz resonator pressure transducers configured to provide integral temperature compensation and methods of using same.
BACKGROUND
[0003] Quartz resonator pressure transducers have been used successfully in the downhole environment of oil and gas wells for several decades and are still the most accurate means of determining bottom-hole pressure. While many measurements of these downhole pressures are made under static or slowly varying pressure and temperature conditions, some significant situations, however, require pressure measurements under transient conditions where either or both of the temperature and pressure are changing. The range of static to dynamic measurement conditions, the economic drive for less expensive devices, and the increasing levels of pressures and temperatures arising as the world oil and gas exploration and production industry drills deeper and deeper, have spurred continuing developments in quartz resonator pressure transducers.
[0004] The first commercially successful quartz resonator pressure transducer, as disclosed in U.S. Pat. Nos. 3,561,832 and 3,617,780, the disclosure of each of which is hereby incorporated herein in its entirety by this reference, was introduced by Hewlett Packard (“HP”) in the 1970's. This transducer was of a cylindrical design with the resonator formed in a unitary fashion in a single piece of quartz. End caps of quartz were attached to close the structure. FIG. 1A shows this configuration, which contains resonator 1 a unitary (integral) with body 2 a, two end caps 3 a, and two glass joints 4 a. This device was relatively large, approximately 1 inch diameter and 4 inches long. The unitary body and resonator are expensive to manufacture. Also, two major disadvantages were caused by the large size. Large stress distributions occur throughout the structure under transient conditions because the temperature distribution is slow to equilibrate. These stresses cause errors in the pressure measurement. Also, it is not practical to obtain a temperature measurement, necessary for temperature compensation, close to the actual location of the pressure measurement, e.g., the resonator, because of the large transducer size. This lack of proximity results in temperature errors in transient conditions because the temperature at a temperature transducer used to temperature compensation may not be the same as the required temperature located at the resonator itself. Both of these problems restricted the use of this concept to the more benign, nearly static cases.
[0005] A somewhat smaller size transducer was introduced in the 1980's by Quartztronics, Inc., of Murray, Utah, and commercialized by Halliburton Company through its Halliburton Services operating unit, now part of Halliburton Energy Services. This device, as described in U.S. Pat. Nos. 4,550,610 and 4,660,420, the disclosure of each of which is hereby incorporated herein in its entirety by this reference, was similar to the unitary HP design, except diametrically opposed flats were added to the cylindrical shape to create a non-uniform stress distribution in the resonator under pressure. FIG. 1B shows this structure, which contains resonator 1 b unitary with body 2 b, two end caps 3 b, two glass joints 4 b, and a pair of flats 5 b (backside flat not shown in FIG. 1B ). The smaller size of the Quartztronics transducer reduced the cost, and the flats increased the pressure sensitivity while reducing the temperature sensitivity. The smaller size also reduced the amount of undesired stress distribution from non-uniform thermal distributions and enabled temperature to be measured closer to the pressure measurement location.
[0006] Another quartz resonator transducer design was introduced in the 1990's by Quartzdyne, Inc. of Murray, Utah. This device eliminated the body/resonator unitary structure by simply bonding a convex-convex resonator between two end caps. FIG. 1C shows this configuration, which contains resonator 1 c, two endcaps 3 c, and two glass joints 4 c. Besides low cost, the physical size was small enough to move the temperature measurement point to within a few millimeters of the pressure measurement location.
[0007] The foregoing three quartz resonator transducers each use a single resonant mode, the slow-shear thickness mode, or C-mode, to determine pressure external to the transducer. A temperature compensation signal is supplied with an independent temperature measurement device located as close as possible to the pressure measurement (resonator) location.
[0008] In light of recognition of a need for good pressure measurements in transient conditions, researchers have explored different ways to use a dual-mode transducer, wherein two resonant modes are driven by the driving circuits of the transducer at the same time. In a dual-mode transducer, one resonant mode is mainly dependent on pressure, the other mode is mainly dependent on temperature. This approach would provide a temperature measurement located exactly where the pressure measurement was made, eliminating one important error source. One mode, usually the C-mode, is used to measure the pressure, and a second mode, the fast-shear mode, or B-mode, is used to determine the temperature. With the two unknowns, pressure and temperature, and two simultaneous measurements, one can solve the two equations. However, during a transient condition, the non-uniform stresses in the structure, arising from non-uniform temperature distributions therein, changes the resonant frequencies. If the B-mode is pressure sensitive, this frequency error will cause an error in the temperature calculation which will, in turn, cause an error in the calculation of the pressure. One is forced to perform a series of iterative calculations that may not lead to accurate pressure and temperature answers. The simplicity and accuracy of the pressure calculation in this case is greatly enhanced if the B-mode is not pressure sensitive. This fact has driven research efforts in dual-mode transducers to find B-modes with no pressure sensitivity while still having a C-mode available for the pressure measurement.
[0009] It has been recognized that one way to obtain a B-mode that is independent of pressure is to change the crystallographic orientation of the quartz in the device. This approach led to the SBTC orientation, as described in Michel Valdois, Bikash K. Sinha, and Jean Jacques Boy, EXPERIMENTAL VERIFICATION OF STRESS COMPENSATION IN THE SBTC-CUT, IEEE Trans. Ultrasonics, Ferroelectrics, and Frequency Control, Vol. 36, p. 643, 1989, the disclosure of which is hereby incorporated herein in its entirety by this reference. The shape of the SBTC orientation transducer is identical to that shown in FIG. 1A . Although this concept was successful in obtaining a B-mode with no pressure sensitivity, the C-mode was not usable in a practical oscillator circuit because of high electrical resistance.
[0010] Another approach to quartz resonator transducer design is described in U.S. Pat. No. 4,562,375, the disclosure of which is hereby incorporated herein in its entirety by this reference. This structure uses a resonator bonded between two end caps, similar to the structure depicted in FIG. 1C . However, the resonator in this transducer design includes slots to isolate most of the perimeter of the resonator, leaving small bridges to transfer the force from the endcaps along a specific direction such that the B-mode will be pressure insensitive. This structure has never been used commercially. The reason is believed to be that the design cannot withstand the high pressures experienced in a wellbore without failure because of the stress concentrations in the corners of the slots.
[0011] To date, the only commercially successful dual-mode quartz pressure transducer is the CQG (Crystal Quartz Gauge), offered by Schlumberger and described in U.S. Pat. Nos. 4,547,691, 5,394,345 and 6,147,437, the disclosure of each of which is hereby incorporated herein in its entirety by this reference. It is a radical departure from the previous structures in that, although the exterior is essentially cylindrical, the resonator is suspended across the inside diameter with the plane of the resonator extending in the axial direction. FIG. 2 shows the CQG structure, which contains resonator 1 d unitary with body 2 d, two end caps 3 d, and two glass joints 4 d. The drawings of the patents relating to this structure show it with no flats, as well as with flats 5 d. There is an additional small flat 6 d, as shown. This small flat 6 d is shallow enough that it does not appreciably affect the stress magnitude or distribution in the resonator 1 d, and is apparently used for assembly facilitation to crystallographically orient the end caps 3 d with the body 2 d. Whereas all previous transducer structures previously mentioned herein exhibit a two-dimensional stress in the resonator, the CQG structure has an almost uniaxial stress pattern in the resonator. The orientation of the resonator can be selected so that the B-mode is pressure insensitive.
[0012] There have been several attempts to accomplish dual-mode operation in a structure resembling the Quartztronics design employed by Halliburton, where the stress in the resonator is two-dimensional, but not uniform. One approach is described in U.S. Pat. No. 6,455,985, the disclosure of which is hereby incorporated herein in its entirety by this reference. In this design, the unitary body with the resonator is cylindrical. However, the end caps, while being cylindrical on the outside, are stiffened inside along one direction to create a non-uniform stress in the resonator. A second approach is described in U.S. Pat. No. 6,111,340 (the “'340 patent”), the disclosure of which is hereby incorporated herein in its entirety by this reference. In this design, the structure is the same as the shape employed in the Quartztronics/Halliburton transducer, the only difference being that it is a dual-mode device. However, the '340 patent demonstrates that, even with very deep flats that take up two-thirds (⅔) of the wall thickness, it is not possible to render the B-mode completely independent of pressure but suggests that, if the pressure sensitivity of the B-mode can be reduced sufficiently with the use of the flats, a usable device is possible. This invention would appear to be useful only if the flats are very deep. However, the stress concentrations associated with deep flats may lead to cracking or twinning, and are not consistent with an ongoing desire prevalent throughout the industry to extend the upper limits of pressure and temperature measurement.
[0013] As disclosed in Schodowski, RESONATOR SELF-TEMPERATURE-SENSING USING A DUAL-HARMONIC-MODE CRYSTAL OSCILLATOR, 43r d Annual Symposium on Frequency Control, 1989, p. 2 and U.S. Pat. No. 4,872,765 to Schodowski as well as in U.S. Pat. No. 4,545,638 to EerNisse and Ward, the disclosure of each of which is hereby incorporated herein in its entirety by this reference, temperature compensation is accomplished by using two harmonically related resonances, typically the C-mode fundamental and 3r d overtone. The temperature is calculated using the formula 3*f Cfund −f C3rd . This use of harmonically related vibrational modes must, however, include the fundamental mode to obtain the temperature sensitivity. As the fundamental mode is more spread out than the overtones, a device employing this approach requires a relatively large resonator bore diameter, leaving many unwanted modes not clamped and increasing the chances for an activity dip.
[0014] One limitation common to all the quartz resonator pressure transducer concepts is a tendency toward twinning at high applied stress and temperature. Twinning is not reversible and renders the device unusable. In the past few years, the pressures and temperatures encountered in the deeper wells have exceeded the capabilities of the CQG structure, which has stress concentrations in edges and corners. Twinning is less prevalent in designs such as those of FIGS. 1A and 1C with uniform two-dimensional stress in the resonator. Also, because these cylindrical structures minimize the number of corners and edges, cracking and twinning in the rest of the structure is less probable.
BRIEF SUMMARY
[0015] Embodiments of the present disclosure employ a substantially cylindrical quartz crystal transducer structure that exhibits a low probability of twinning, and uses a combination of signal inputs at the B-mode and C-mode frequencies to calculate temperature. A range of crystallographic orientations are available where a combination of the B-mode and C-mode frequencies exists that is sufficiently independent of pressure to enable accurate calculation of temperature under transient conditions. Thus, quartz structures, according to the present disclosure, may be used to provide a dual-mode pressure transducer with superior performance in comparison to conventional quartz pressure transducers. In addition, quartz structures of transducers of the present disclosure are less prone to twinning, so such transducers can be used at higher pressures and temperatures than conventional quartz pressure transducers. Furthermore, because the structure of the present disclosure allows a choice of crystallographic orientation, the designer is free to optimize other characteristics, such as increased pressure sensitivity and activity dip-free operation, by varying crystallographic orientation.
[0016] In one embodiment, a dual-mode pressure transducer comprises a quartz crystal structure having a crystallographic orientation with phi between about 24° and less than about 30°, wherein the quartz crystal structure comprises a substantially cylindrical body having a longitudinal bore; and a disc-shaped resonator carried by the body and extending transversely across the longitudinal bore.
[0017] In another embodiment, a dual-mode pressure transducer comprises a quartz crystal structure comprising a resonator and having a crystallographic orientation adapted to provide a combination of signal inputs from a non-fundamental B-mode resonant frequency and a non-fundamental C-mode resonant frequency of the resonator to enable calculation of temperature of the resonator under transient conditions, wherein the quartz crystal structure comprises a substantially cylindrical body having a longitudinal bore and the resonator is disc-shaped, carried by the body and extends transversely across the longitudinal bore.
[0018] In a further embodiment, a method of measuring a temperature-compensated pressure using a quartz crystal structure comprises stimulating, under transient temperature conditions, a resonator under external pressure applied to the quartz crystal structure to provide signal inputs from a non-fundamental B-mode resonant frequency and a non-fundamental C-mode resonant frequency and using a combination of the signal inputs to compensate a pressure determined from the non-fundamental C-mode resonant frequency signal input.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] FIG. 1A is a perspective cutaway view of a prior art quartz pressure transducer configuration;
[0020] FIG. 1B is a perspective cutaway view of another prior art quartz pressure transducer configuration;
[0021] FIG. 1C is a perspective cutaway view of a further prior art quartz pressure transducer configuration;
[0022] FIG. 2 is a perspective cutaway view of yet another prior art quartz pressure transducer configuration;
[0023] FIG. 3 is a graph of frequency shift versus temperature for phi=26° at various pressures;
[0024] FIG. 4 is a graph of slope of frequency shift versus temperature for phi=26° at various pressures;
[0025] FIG. 5 is a graph of calculated pressure sensitivity of the B- and C-modes of a round quartz pressure transducer versus phi angle;
[0026] FIG. 6 is a graph of the error factor in calculated static pressure for f C +f B temperature errors due to the H stress;
[0027] FIG. 7 is a graph of slope in Hz/psi an indicated combination of f C and f B versus T, calculated using experimental data from a phi=26° quartz pressure transducer; and
[0028] FIG. 8 is a schematic diagram of a circuit suitable for use with embodiments of a quartz crystal pressure transducer according to embodiments of the present disclosure.
DETAILED DESCRIPTION
[0029] To facilitate a more complete understanding of embodiments of the present disclosure and their operation, it is prudent here to develop a basis for evaluating what errors will occur in a dual-mode transducer given a known level of pressure sensitivity of the B-mode, or in the present case, of the sum of f C and f B . This will be done using some conventional methods for describing the relationship of f C and f B with pressure and temperature.
[0030] Equations for using two modes for computing pressure, P, and temperature, T, are described, for instance, in R. J. Besson et. al., A DUAL-MODE THICKNESS-SHEAR QUARTZ PRESSURE SENSOR, IEEE Trans. Ultrasonics, ferroelectrics, and Frequency Control, Vol. 40, p. 584, 1993, the disclosure of which is hereby incorporated herein in its entirety by this reference. These equations express the pressure and temperature in two-dimensional power series expansions in the two variables, f C and f B , which are the measured frequencies of the C-mode and B-mode, respectively. This approach works well because of the smooth behavior of f C and f B with pressure and temperature.
[0031] FIG. 3 shows the behavior of f C for a device comprising a transducer structured according to an embodiment of the present disclosure when subjected to a static P and T. The f C value at atmospheric pressure and a temperature of 25° C. is typically 7.26 MHz. For the behavior illustrated in FIG. 3 , the outside diameter of an embodiment of the device configured as shown in FIG. 1C is 0.575 inch, the bore diameter of the end caps is 0.300 inch and bore depth is 0.120 inch. The resonator is a 3 rd overtone blank with a diopter of 2.5 on both sides. The crystallographic orientation is phi=26° and theta is near 34°. As known to those of ordinary skill in the art, the angle phi is the angle between the X-axis and the line of intersection of the blank or atomic plane with the XY-plane of a conventionally employed rectangular coordinate system, while theta is the angle between the Z-axis and the plane of the blank or atomic plane. The appropriate theta angle may be chosen such that the first order temperature coefficient of the C-mode is zero. This may be calculated according to the following equation, known to those of ordinary skill in the art:
[0000] Θ=35.25°−(11/180)×Φ
[0000] The viable pressure range extends to about 30,000 psi and the temperature range is 25° C. to 200° C.
[0032] Embodiments of the present disclosure may be physically implemented utilizing the quartz crystal structures illustrated herein in FIGS. 1A and 1C . As noted previously, FIG. 1A depicts a unitary resonator and body with end caps at each end of the body, whereas FIG. 1C depicts a resonator sandwiched between two end caps comprising the body. For example, quartz crystal structures in accordance with the present disclosure may include a convex-convex resonator and two end caps. In other embodiments, the quartz crystal structures in accordance with the present disclosure may include other resonators configurations such as plano-plano and plano-convex.
[0033] Referring to FIG. 3 , changes in f C exhibit smooth behavior with shifts in pressure over a wide range of temperatures. The following approach is taken for a theoretical development of the possible errors in using a dual-mode device in a transient situation. At a given static pressure P 1 and static temperature T 1 , the f C and f B behavior can be described for small excursions in P and T around P 1 and T 1 with a Taylor series expansion. The expansion is limited to terms linear in P and T and any cross-products of P and T are ignored.
[0000]
f
C
=
f
C
1
+
∂
f
C
∂
T
*
(
T
-
T
1
)
+
∂
f
C
∂
P
*
(
P
-
P
1
)
(
1
)
f
B
=
f
B
1
+
∂
f
B
∂
T
*
(
T
-
T
1
)
+
∂
f
B
∂
P
*
(
P
-
P
1
)
(
2
)
[0034] If the constants C T , C P , B T , and B P are defined as follows,
[0000]
C
T
=
1
f
C
1
∂
f
C
∂
T
C
T
=
1
f
C
1
∂
f
C
∂
P
B
T
=
1
f
C
1
∂
f
B
∂
T
B
P
=
1
f
C
1
∂
f
B
∂
P
,
(
3
)
[0000] then equations 1 and 2 can be written as
[0000] f C =f C1 +f C1 C T *( T−T 1 )+ f C1 C P *( P−P 1 ) (4)
[0000] f B =f B1 +f B1 B T *( T−T 1 )+ f B1 B P *( P−P 1 ) (5)
[0035] Equation 4 can be used in development of an error budget by answering the question: How accurate does one need to know T to calculate P to a given accuracy level? Using Equation 4, we can solve for an error in f C , Δf C , caused by an error in T, ΔT, given that P=P 1 .
[0000] Δ f c =f C1 C T ΔT. (6)
[0000] Now, assuming that T=T 1 , Equation 4 can be solved for P in terms of f C .
[0000]
P
-
P
1
=
(
f
C
-
f
C
1
)
f
C
1
C
P
.
(
7
)
[0000] If Equation 6 is substituted into Eq. 7, the error in P, ΔP, can be estimated as
[0000]
Δ
P
=
C
T
C
P
Δ
T
.
(
8
)
[0000] As shown by the equation, a combination of a low temperature sensitivity (small C T ) and a large pressure sensitivity (large C P ) minimizes the P error, ΔP, due to an error in T.
[0036] When there is a transient situation involving a temperature shift, there are stresses created in the resonator due to a non-uniform temperature distribution in the resonator. This stress value at the center of the resonator causes a frequency shift that is an error in indicated pressure, which will be termed H. It is conventional to use f B for the calculation of T. Using Equation 5, the error in T, ΔT, caused by H is
[0000]
Δ
T
=
B
P
B
T
H
.
(
9
)
[0037] Thus, an error in the calculated pressure from ΔT caused by H is represented by
[0000]
Δ
T
=
C
T
C
P
B
P
B
T
H
.
(
10
)
[0000] This is the error that arises from the pressure sensitivity of f B . It is known in the art to have B P small and B T large, as well as small C T and large C P . The numbers provided in U.S. Pat. No. 6,111,340 may be used to calculate the coefficient in Equation 10 that the inventors therein considered practical, i.e., “substantially insensitive” to pressure, (|B P |≈|C P |, and |C T |≈3 ppm/° C. and |B T |≈28 ppm/° C.). The coefficient is 0.107. This indicates that the error in calculating P due to the non-uniform temperature distribution is approximately ten times (10×) less than H, the indicated error in P arising from the non-uniform temperature distribution during a transient event. One may proceed from here assuming that 10× is an approximate threshold for practical dual-mode performance.
[0038] FIG. 4 shows the slope of FIG. 3 in ppm/° C. for an embodiment of a quartz pressure transducer according to the present disclosure at phi=26°. The crystallographic orientation has been adjusted to minimize the magnitude of the slope over the entire pressure and temperature ranges to be 3 ppm/° C. This number may be used as one design parameter for evaluating an error budget and this number is approximately the same over the range of phi from 22° to 30°. Also, the B T coefficient is found to be approximately 28 ppm/° C. over this phi range. One may proceed with these two numbers assumed to be relatively constant over the phi range under consideration herein for implementation of one embodiment of the present disclosure.
[0039] One form of the present disclosure uses f C +f B for the temperature calculation. An equation may be derived for this case that is equivalent to Equation 10 for the error in P due to H. Assume that P=P 1 . Then, the change in temperature ΔT is calculated from Equations 4 and 5 by
[0000]
Δ
T
=
(
f
C
+
f
B
-
f
C
1
-
f
B
1
)
(
f
C
1
C
T
+
f
B
1
B
T
)
.
(
11
)
[0000] Assume that T=T 1 . Then if the non-uniform stress is present and there is an error in the indicated pressure of H, the error in frequency for f C +f B is given by
[0000] ( f C +f B −f C1 −f B1 )=( f c1 C P +f B1 B P ) H. (12)
[0000] When Equations 11 and 12 are combined, the error in T is given by
[0000]
Δ
T
=
(
f
C
1
C
P
+
f
B
1
B
P
)
(
f
C
1
C
T
+
f
B
1
B
T
)
H
.
(
13
)
[0000] Equation 13 for the error in T, combined with Equation 8, provides us with the equivalent of Equation 10:
[0000]
Δ
P
=
C
T
C
P
(
f
C
1
C
P
+
f
B
1
B
P
)
(
f
C
1
C
T
+
f
B
1
B
T
)
H
.
(
14
)
[0000] Equation 14 represents a significant aspect of the disclosure. Instead of B P and B T in Equation 10, which are in ppm/psi and ppm/° C., in the present disclosure the coefficients in the parenthesis are calculated using Hz/psi and Hz/° C. The power of this approach becomes evident when looking at FIG. 5 . There, the calculated values are shown for f C1 *C P and f B1 *B p , as well as the sum (f C1 *C P +f B1 *B p ) for a round sensor design according to an embodiment of the disclosure over the range of phi angles from 22° to 30°. Since the values are of opposite sign, the sum trends toward zero for phi near 30°.
[0040] The impact of choice of phi angle is also influenced by the fact that C P is zero near phi=22° for a round sensor and trends approximately linearly toward −1.5 ppm/psi at phi =30° . Since C P is in the denominator of Equation 14, the effect of the phi angle on the coefficient in Equation 14 is dramatic. FIG. 6 shows the coefficient in Equation 14 vs. phi angle. It is apparent from FIG. 6 that a round sensor can be used for a dual-mode pressure transducer for phi angles greater than about 25°, where the 10× criteria is approximately satisfied. If one is more aggressive and chooses 5× for the criteria, the lower end of the range of usable phi angles falls to 24° . Although the curve in FIG. 6 is theoretical, the experimental point obtained in this work and shown in FIG. 6 supports the theoretical results.
[0041] The use of the sum for f C and f B is a result of concentrating attention on the phi angle range in FIG. 5 . Since C P passes through zero around phi of 22°, at lower phi angles one may use the difference f B −f C to reduce the error arising in transient conditions. Here, using the difference, the appropriate equation relating the pressure error to H is given by
[0000]
Δ
P
=
C
T
C
P
(
f
B
1
B
P
+
f
C
1
C
P
)
(
f
B
1
B
T
+
f
C
1
C
T
)
H
.
(
15
)
[0042] The form of Equation 14 may be maintained by dividing both numerator and denominator of Equation 15 by −1:
[0000]
Δ
P
=
C
T
C
P
(
f
C
1
C
P
+
f
B
1
B
P
)
(
f
C
1
C
T
+
f
B
1
B
T
)
H
.
(
16
)
[0043] The most general form of the present disclosure is based on the fact that once one has the values for f C and f B , one is free to perform almost any desired calculation. Thus, we may use f C +K*f B to compute T, where K is a scalar number. The equations for this case may be easily derived. Substituting K*f B and K*f B1 for f B and f B1 , respectively, in Equation 11, the following equation for computing a change in T can be written as
[0000]
Δ
T
=
(
f
C
+
Kf
B
-
f
C
1
-
Kf
B
1
)
(
f
C
1
C
T
+
Kf
B
1
B
T
)
.
(
17
)
[0044] If the same substitutions are made into Equation 13, the error in T due to the presence of H may be found:
[0000]
Δ
T
=
(
f
C
1
C
P
+
Kf
B
1
B
P
)
(
f
C
1
C
T
+
Kf
B
1
B
T
)
H
.
(
18
)
[0045] Equation 18 may be used in Equation 8 to arrive at the most general case of the present disclosure:
[0000]
Δ
P
=
C
T
C
P
(
f
C
1
C
P
+
Kf
B
1
B
P
)
(
f
C
1
C
T
+
Kf
B
1
B
T
)
H
.
(
19
)
[0046] Note that Equation 19 becomes Equation 14 when K=1, and becomes Equation 16 when K=−1. However, K may be adjusted to minimize the term f C1 *C P +K*f B1 *B P in Equation 19. This has been done for some calibration data of the sensor used for the experimental point in FIG. 5 . The result is shown in FIG. 7 , where a K of 0.606 was found to reduce the numerator of Equation 19 over the temperature range employed to practically zero. The fact that there is some small T dependence in FIG. 7 arises because f C and f B are not perfectly linear with P and T. Since it has already been shown that the value of 0.33 Hz/psi for f C +f B is adequate for actual use, the greatly reduced value in FIG. 7 will provide even superior performance.
[0047] Thus, one significant benefit of this disclosure is that by proper choice of the combination f C +K*f B , one can now choose the angle phi for the crystallographic orientation of the sensor for other reasons. One option is to choose a phi angle far from 22° to obtain a large pressure sensitivity of f C . Another important consideration is that both the C-mode and B-mode must be free of significant activity dips. Yet another consideration is that the resistance of the two modes changes greatly with phi, so, depending on the circuits to be used in conjunction with the transducer, it may be desirable to adjust phi appropriately.
[0048] It should be noted that the use of the deep flats on the transducer body as disclosed in the '340 patent might, if desired, be used to improve the present disclosure in terms of reducing f C +f B over that obtained from a round-bodied unit. We can understand this by looking at FIG. 5 . With judicious choice of the orientation of the flats, the stresses in the resonator become non-uniform. This can cause the curve for the B-mode to move downward to lower positive values as the P sensitivity decreases, and lower the curve for the C-mode toward larger magnitude, but negative, values for the C-mode as the P sensitivity increases. This reduces the sum f C +f B over the value for a round unit. However, the use of flats of any significant depth to create non-uniform stress distributions in the resonator, and in the end caps, may unfortunately increase the potential for twinning, or cracking. In addition, the use of flats may be unnecessary with the present disclosure because the function to be provided by the flats can be effected with f C +K*f B .
[0049] It should be emphasized that conventional quartz transducer construction practices utilize small exterior flats for alignment purposes during assembly, but such flats are sufficiently small to not cause any appreciable non-uniform stress in the resonator and, accordingly, the term “flat” as applied to quartz transducer structures means and includes a flat or flats of sufficient magnitude to induce non-uniform stress in a resonator of such transducer structures under applied exterior pressure. For example, a transducer body in accordance with at least one embodiment of the present disclosure may include two large flats and two smaller flats, each being offset about 90° about the body of the transducer as shown in FIG. 2 . Such a configuration may aid in the assembly of the transducer body by helping to ensure that the end caps and resonator are assembled in the correct orientation. Accordingly, the term “substantially cylindrical” as used herein with regard to quartz transducer structures means and includes structures devoid of a flat or flats of sufficient magnitude to induce non-uniform stress in a resonator of such a quartz transducer structure. For example, a substantially cylindrical transducer body may include one or more flats to aid in the assembly of the transducer body as discussed above.
[0050] FIG. 8 is a schematic diagram of a circuit 100 suitable for use with embodiments of a quartz crystal pressure transducer according to embodiments of the present disclosure. As shown in FIG. 8 , the circuit 100 includes a first oscillator 102 driven by a first amplifier 104 for driving a reference crystal (e.g., one of resonators 1 a, 1 b, 1 c ( FIGS. 1A-1C )) at a selected frequency (e.g., about 7.2 MHz). The circuit 100 includes one more oscillators (e.g., oscillator 106 driven by amplifier 108 ) for driving another crystal (e.g., one of resonators 1 a, 1 b, 1 c ) that acts as a dual-mode sensor. For example, the oscillator 106 may drive the dual-mode sensor crystal at two different frequencies (e.g., a C-mode of about 7.24 MHz and a B-mode of about 7.8 MHz) to provide both pressure and temperature measurements from a single crystal. In other embodiments, two oscillators may be utilized to drive the single crystal to provide both pressure and temperature measurements from the single crystal. A frequency signal from the reference crystal may be sent to a processor 110 (e.g., a microcomputer) for further processing, if desired, and that may be outputted to a reference output F REF .
[0051] One or more frequency signals from the dual-mode sensor crystal (e.g., two frequency signals created by the oscillator 106 driving the crystal at two different frequencies) may be may be sent to the processor 110 for further processing, if desired, and for use in the equations for temperature and pressure as set forth above. The results of those calculations may be outputted to output F TEMP and output F REF .
[0052] In contrast with the state of the art as exemplified by Schodowsky and U.S. Pat. No. 4,545,638 to EerNisse and Ward, embodiments of the present disclosure do not employ the use of harmonically related vibrational modes that require inclusion of the fundamental mode to obtain the required temperature sensitivity and, consequently, avoid the requirement of a relatively large resonator bore diameter and the associate disadvantages indicated above.
[0053] For example, in a practical implementation of an embodiment of the present disclosure, any harmonic higher than the fundamental is about the same mode shape and, therefore, usable. Consequently, embodiments of the present disclosure may employ the 3 rd harmonic of both the B- and C-modes, or a 3 rd of one of the B-mode and the C-mode and a 5 th of the other, for temperature calculation and compensation purposes.
[0054] While the disclosure may be susceptible to various modifications and alternative forms, specific embodiments have been shown by way of example in the drawings and have been described in detail herein. However, it should be understood that the invention is not intended to be limited to the particular forms disclosed. Rather, the invention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention as defined by the following appended claims. | A cylindrical quartz crystal transducer that exhibits a low probability of twinning, and uses a combination of resonator signal inputs at the B-mode and C-mode frequencies to calculate resonator temperature. Crystallographic orientations are disclosed where combinations of B-mode and C-mode resonant frequencies exist that are sufficiently independent of pressure to enable accurate calculation of temperature under transient conditions. Such a transducer is usable at higher pressures and temperatures than conventional quartz pressure transducers. Furthermore, because the structure allows a choice of crystallographic orientation, other characteristics of the transducer, such as increased pressure sensitivity and activity dip-free operation, may be optimized by varying crystallographic orientation. | 4 |
BACKGROUND OF THE INVENTION
This invention relates to nitrile polymers stabilized against color degradation caused by ionizing radiation. More particularly, this invention involves the stabilization of nitrile polymers against such discoloration by inclusion of an effective amount of a sulfur containing stabilizer and a sulfur containing plasticizer.
In recent years it has been discovered that certain nitrile polymers having a high proportionate amount of olefinic nitrile component are especially suitable for packaging, test tubes, syringes and other applications particularly because of their excellent water and oxygen barrier properties. However, such nitrile polymers have a tendency to discolor particularly when subject to ionizing radiation used in treating articles made from such nitrile polymers. While a variety of compounds and particularly phenol compounds and triazine compounds such as disclosed in U.S. Pat. No. 3,202,681 and 4,046,735 have been generally known to be useful as stabilizers for various organic compositions, many of such stabilizers are not particularly useful for stabilizing nitrile polymers against color degradation caused by ionizing radiation, e.g. alpha, beta, gamma and electron beam radiation.
Thus, there exists in the art a need for an improved nitrile polymer which is stabilized against color degradation caused by ionizing radiation. This need is provided by the present invention wherein selected sulfur containing compounds are added to the nitrile resin composition.
SUMMARY OF THE INVENTION
The present invention fulfills the aforementioned need by providing nitrile polymers which are stabilized against color degradation caused by ionizing radiation by the addition of a stabilizing agent comprising a combination of selected sulfur containing compounds as stabilizers and sulfur containing plasticizers. More particularly this invention provides a color stable polymer composition comprising at least 40% by weight of an olefinically unsaturated nitrile monomer having the formula: ##STR1## wherein R is hydrogen, a lower alkyl having from 1 to 4 carbon atoms or a halogen and an effective amount of a stabilizing agent.
DETAILED DESCRIPTION OF THE INVENTION
The nitrile polymers of this invention are prepared from at least 40% by weight of an olefinically unsaturated nitrile monomer having the formula: ##STR2## wherein R is hydrogen, a lower alkyl having 1 to 4 carbon atoms or an halogen. Such compounds include acrylonitrile, methacrylonitrile ethacrylonitrile, propioacrylonitrile, alpha chloroacrylonitrile, etc. The most preferred olefinically unsaturated nitriles are acrylonitrile and methacrylonitrile and mixtures thereof.
The nitrile polymer of this invention may contain a comonomer copolymerizable with the olefinically unsaturated nitriles and including:
a. the monovinylidene aromatic hydrocarbon monomers of the formula: ##STR3## wherein R 4 is hydrogen, chlorine or methyl and R 5 is an aryl group of 6 to 10 carbon atoms and may also contain substitutes such as halogen as well as alkyl groups attached to the aromatic nucleus, e.g. styrene, alpha methylstyrene, vinyl toluene, alpha chlorostyrene, ortho chlorostyrene, meta chlorostyrene, para chlorostyrene, ortho methylstyrene, para methylstyrene, ethyl styrene, isopropyl styrene, dichloro styrene, vinyl naphthalene, etc.
b. lower alpha olefins of from 2 to 8 carbon atoms, e.g. ethylene, propylene, isobutylene, butene-1, pentene-1 and their halogen and aliphatic substituted derivatives e.g. vinyl chloride, vinylidene chloride, etc.
c. acrylic acid and methacrylic acid and the corresponding acrylate and methacrylate alkyl esters wherein the alkyl group contains from 1 to 4 carbon atoms, e.g. methyl acrylate, ethyl acrylate, propyl acrylate, methyl methacrylate, etc.
d. vinyl esters of the formula: ##STR4## wherein R 6 is hydrogen, an alkyl group of from 1 to 10 carbon atoms, an aryl group of 6 to 10 carbon atoms, e.g. vinyl formate, vinyl acetate, vinyl propionate, vinyl benzoate, etc.
e. vinyl ether monomers of the formula:
H.sub.2 C═CH--O--R.sup.7
wherein R 7 is an alkyl group of from 1 to 8 carbon atoms, an aryl group of from 6 to 10 carbon atoms or a monovalent aliphatic radical of from 2 to 10 carbon atoms, which aliphatic radical may be hydrocarbon or oxygen containing, i.e. an aliphatic radical with ether linkages and may also contain other substituents such as halogen, carbonyl, etc. Examples of these monomeric vinyl ethers include vinyl methyl ether, vinyl ethyl ether, vinyl n-butyl ether, vinyl 2-chloroethyl ether, vinyl phenyl ether, vinyl cyclohexyl ether, 4-butyl cyclohexyl ether, and vinyl p-chlorophenylene glycol ether, etc.
Other useful comonomers in the practice of this invention are the lower alkyl itaconicate and fumarate esters and those comonomers which contain a mono- or di-nitrile function. Examples of these include methylene glutaronitrile, 2,4-dicyanobutene-1, vinylidene cyanide, crotonitrile, fumarodinitrile, maleodinitrile. The preferred comonomers are the monovinylidene aromatic hydrocarbons, lower alpha olefins and acrylic and methacrylic acid and the corresponding acrylate and methacrylate esters with the monovinylidene aromatic hydrocarbons being more particularly preferred. More specifically preferred is styrene and alpha methylstyrene.
This invention also contemplates the use of a synthetic or natural rubber component such as polybutadiene, isoprene, neoprene, nitrile rubbers, natural rubbers, acrylonitrile-butadiene copolymers, ethylene-propylene copolymers, chlorinated rubbers, etc., which are used to strengthen or toughen the nitrile polymers of this invention. This rubbery component may be incorporated into the nitrile containing polymer by any of the methods which are well known to those skilled in the art, e.g., direct polymerization of monomers, polyblends, grafting the acrylonitrile monomer mixture onto the rubbery backbone, etc. Especially preferred are polyblends derived by mixing a graft copolymer of acrylonitrile and comonomer on the rubbery backbone with another copolymer of acrylonitrile and the same comonomer. Generally, such rubber component may comprise from 0 to about 25% and preferably up to about 10% by weight of the nitrile polymer composition.
The sulfur containing stabilizers used in this invention are selected from the group consisting of:
thioglycerol
glycerol dimercaptoacetate
thiodiethanol
t-dodecyl mercaptan; and
dibenzyl disulfide
The sulfur containing plasticizers used in this invention are selected from the group consisting of:
N-aryl sulfonamides
N-alkyl aryl sulfonamides; and
N-toluene sulfonamide-formaldehyde
wherein the alkyl group contains 2 to 6 carbon atoms and the aryl group contains 6 to 9 carbon atoms, with the preferred alkyl groups being ethyl, propyl, isopropyl, butyl and isobutyl and the preferred aryl groups being benzene and toluene. Especially preferred are benzene sulfonamide, toluene sulfonamide, N-ethyl o,p-toluene sulfonamide, N-butyl benzene sulfonamide, N-propylbenzene sulfonamide and N-isopropylbenzene sulfonamide.
The amount of the sulfur containing stabilizer used in this invention is from about 0.05 to about 1.0% and preferably 0.1 to 0.5% by weight of stabilizing agent based on the total weight of the nitrile polymer. The amount of sulfur containing plasticizers used in combination with the sulfur containing stabilizer is from about 0.5 to 7.0 and preferably from 1.0 to 0% by weight based on the total weight of the nitrile polymer.
The sulfur containing stabilizers, sulfur containing plasticizers and nitrile polymers are well known and are generally available. The nitrile polymers may be prepared by any of the known general techniques of polymerization including bulk or mass polymerization, solution polymerization and emulsion or suspension polymerization.
The nitrile monomer component will preferably comprise from about 50 to about 90% and more preferably from about 55 to about 80% by weight, based on the total weight of the nitrile polymer.
The stabilizers and plasticizers are generally incorporated into the nitrile polymer by blending. This may be carried out for example by adding them to the nitrile polymer in the polymer recovery steps such as during coagulation, stripping, washing, drying, etc. or by steeping the polymer in a liquid containing the stabilizers and plasticizers. A preferred method is to dry blend the nitrile polymer, stabilizers and plasticizer prior to any fabrication steps. This may be done in any of the suitable commercially available equipment, e.g. Henschel mixers, Pappenmeier mills and the like. An especially convenient method for compounding involves dispersing the sulfur containing stabilizer in the sulfur containing plasticizer, adding the combination to the nitrile polymer and then heating and mixing. Other conventional additives may also be included in the plasticizer/stabilizer component or added to the nitrile polymer separately. These additives included, but are not limited to, dyes, pigments, thermal stabilizers, antioxidants, lubricants and the like.
The sulfur containing stabilizers and sulfur containing plasticizers when used alone in the present invention reduce the amount of color caused by irradiation. However, the most effective way to achieve a color reduction of at least 50% is to use a combination of stabilizer and plasticizer.
The following examples are set forth in illustration of the present invention and should not be construed as limitations thereof.
In the following examples, the nitrile polymer in bead form, the sulfur containing stabilizer and/or sulfur containing plasticizers are blended in a Pappenmeier mill, heated to 90° C. for a time sufficient to allow the stabilizer and plasticizer to be absorbed by the beads, e.g. usually about 5 to 10 minutes. At this point the beads usually become sticky. The batch is then cooled to the point where the stabilized beads flow freely, e.g. about 40 to 50° C. and then the compounded beads are removed from the mill. The stabilized beads are then molded into chips about 10.5 by 7.7 by 1.5 mm in size for color testing after irradiation. The molded chips are exposed to 3.5 megarads of electron beam radiation. The molded chips are passed on a belt through an irradiated field having a strength of 3 million electron volts (MEV) at 1 milliamp (ma). One pass at a belt speed of 43.2 centimeters per minute is equivalent to a dose of 3.5 megarads. The irradiation unit is manufactured by High Voltage Engineering. A Pacific Scientific XL-835 colorimeter unit is used for measuring color. The unit uses the tristimulus system (X, Y, and Z measurements) according to ASTM test D-1925.
EXAMPLE 1
A nitrile polymer containing 62% by wt of acrylonitrile and 38% by wt of styrene is compounded with various sulfur containing stabilizers and/or sulfur containing plasticizers, irradiated and tested for color. The yellowness index (YI) of the irradiated stabilized samples is compared to the YI of a control sample which does not contain stabilizer or plasticizer and the % reduction in YI is calculated by dividing the difference in YI of the control and the stabilized sample by the YI of the control.
TABLE 1______________________________________ % % Control Stabilized Reduc-Stabilizer by wt.sup.(1) YI.sup.(2) YI tion______________________________________Thioglycerol 0.2 41.7 31.2 25t-dodecyl mercaptan 0.2 41.7 36 14glycerol dimercapto- 0.2 41.7 32.5 22acetatethiodiethanol 0.2 42 33.7 20dibenzyl disulfide 1.0 41.7 35.8 14toluene sulfonamide- 2.0 42 28.8 31formaldehydeN-ethyl toluene 2.0 42 25.4 40sulfonamidethioglycerol/N-ethyl 0.2/2.0 41.2 17.1 58toluene sulfonamide______________________________________ .sup.(1) % by weight of stabilizer and plasticizer is based on the weight of the nitrile polymer. .sup.(2) Control is nitrile polymer without stabilizer or plasticizer.
The results in Table 1 show that when thioglycerol and N-ethyl toluene sulfonamide are used in combination there is a drop in color of 58% vs. 25% for the thioglycerol alone, and 40% for the N-ethyle toluene sulfonamide alone.
EXAMPLE 2
The nitrile resin used in Example 1 is compounded with 0.2% by weight thioglycerol and with 3% by weight of various N-alkyl benzene sulfonamides. The color (YI) of the compounded polymer before and after radiation is shown in Table 2 below.
TABLE 2______________________________________ YI YI % YI Before After Reduc-Sulfonamide Radiation Radiation tion.sup.(1)______________________________________Control (no additives) 10.3 43.0 --Control (only thioglycerol) 12.8 23.0 46N-butylbenzene sulfonamide 10.8 16.8 61N-ethylbenzene sulfonamide 12.1 17.2 60N-propylbenzene sulfonamide 14.5 21.1 51N-isopropylbenzene sulfonamide 11.8 18.8 56______________________________________ .sup.(1) % YI reduction over control with no additives
The results in Table 2 show that the nitrile resin without stabilizers undergoes a color increase of from 10.3 to 43.0 while the color of the samples containing both thioglycerol and plasticizer increases to a point in the range of from 16.8 to 21.1.
EXAMPLE 3
In this example, the nitrile polymer used in Example 1 is compounded with 0.5% by weight of dibenzyl disulfide and 2% by weight of N-ethyl o,p-toluene sulfonamide. The initial color (YI) was 8.8 (versus 9.7 for the control with no additives) and the YI after irradiation was 20.2 (versus 41.2 for the control) for an improvement of about 51%.
EXAMPLE 4
In this example, a nitrile polymer containing about 62% acrylonitrile and about 38% styrene and having a YI of greater than the 10.3 value for the nitrile polymer used in Example 1 (as judged visually) is compounded with 3% by weight of N-butyl benzene sulfonamide alone and N-butyl benzene sulfonamide in combination with 0.2% by weight of glycerol dimercapto acetate. The results are set forth below:
TABLE 3______________________________________ Before After Radiation RadiationStabilizer YI YI______________________________________N-butyl benzene sulfonamide 13.8 30.5(alone)glycerol dimercapto acetate 16.9 27.9(combination)______________________________________
EXAMPLE 5
This example lists sulfur containing compounds which do not have a color stabilizing effect on the nitrile polymers used in the present invention. The nitrile polymer used in Example 1 is compounded with 0.2% by weight based on the weight of the nitrile polymer of the sulfur compounds listed below. In each case the color of the compounded nitrile polymer, as judged visually, increased to a degree that the sulfur compounds were deemed unsuitable for use in this invention.
Sulfur Compound
t-nonyl polysulfide
phenothiazine
sulfur
isooctyl thioglycolate
thiodiphenol
benzothiazyl disulfide
depentamethylenethiluram tetrasulfide
tetramethylthiuram disulfide
4-4' dithiomorpholine
4 morpholinyl 2 mercaptobenzothiazole disulfide
selenium diethyl dithiocarbamate
2 mercaptobenzothiazole | Disclosed herein are nitrile polymers which are stabilized against color degradation caused by ionizing radiation by the addition of a stabilizing agent comprising a combination of selected sulfur containing compounds as stabilizers and sulfur containing plasticizers. | 2 |
CROSS REFERENCES TO RELATED APPLICATIONS
[0001] The present application is a continuation of U.S. Ser. No. 12/075,036, filed Mar. 7, 2008, which is a divisional of U.S. Ser. No. 11/418,409, filed May 3, 2006, which claims benefit under 35 U.S.C. 119(e) of U.S. Provisional Application No. 60/684,707, filed May 26, 2005. The entire contents of each of the above-referenced patent applications are hereby expressly incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention is broadly concerned with antibodies specific to antigens of Bartonella henselae and use of these antigens in immunoassays. More particularly, the present invention relates to antibodies specific to the GroES protein, the RpIL protein, an expressed protein of unknown function (the “BepA” protein), the GroEL protein, the SodB protein, the UbiG protein, and the ABC transporter protein of Bartonella henselae , and use of these antigenic proteins in immunoassays in order to determine whether a patient is or was infected with Bartonella henselae.
[0004] 2. Description of the Related Art
[0005] Epidemiological, serological, and molecular studies have implicated Bartonella henselae as the primary causative agent of Cat Scratch Disease (CSD), a frequent self-limiting zoonotic condition which is transferred from cat scratches or bites to people (Bergmans, A. M., J. W. Groothedde, J. F. Schellekens, J. D. van Embden, J. M. Ossewaarde, and L. M. Schouls. 1995. Etiology of cat scratch disease: comparison of polymerase chain reaction detection of Bartonella (formerly Rochalimaea ) and Afipia felis DNA with serology and skin tests. J. Infect. Dis. 171:916-23). Development of CSD is common with a reported incidence rate of 0.77 to 0.86 cases per 100,000 people.
[0006] In the United States, approximately 22,000 people develop CSD annually (Koehler, J. E., C. A. Glaser, and J. W. Tappero. 1994 . Rochalimaea henselae infection. A new zoonosis with the domestic cat as reservoir. JAMA 271:531-5; Peter, J. B., M. Boyle, M. Patnaik, T. L. Hadfield, N. E. Barka, W. A. Schwartzman, and R. S. Penny. 1994. Persistent generalized lymphadenopathy and non-Hodgkin's lymphoma in AIDS: association with Rochalimaea henselae infection. Clin. Diagn. Lab. Immunol. 1:115-6). Approximately 11% of CSD cases are atypical and symptoms can include granulomatous conjunctivitis, oculoglandular syndrome, tonsillitis, visceral granulomatous disease, encephalitis, and cerebral arteritis (Schwartzman, W. A. 1992. Infections due to Rochalimaea : the expanding clinical spectrum. Clin. Infect. Dis. 15:893-900).
[0007] Cats serve as a major reservoir of Bartonella henselae . Pathogen analyses of domesticated cats in the United States have estimated that approximately 28% are chronically infected with Bartonella henselae with no obvious clinical symptoms (Kordick, D. L., K. H. Wilson, D. J. Sexton, T. L. Hadfield, H. A. Berkhoff, and E. B. Breitschwerdt. 1995. Prolonged Bartonella bacteremia in cats associated with cat-scratch disease patients. J. Clin. Microbiol. 33:3245-51).
[0008] Infection with Bartonella henselae in significant cases can result in bacillary angiomatitis or endocarditis. Children and immunocompromised individuals are especially vulnerable to this bacterium. In immunocompromised patients, including those who have been infected with HIV-1 and have developed AIDS, infection with Bartonella henselae can result in bacillary angiomatosis or peliosis hepatis and may also include visceral involvement (Fournier, P. E., and D. Raoult. 1998. Cat scratch disease and an overview of other Bartonella henselae related infections, p. 32-62. In A. Schmidt (ed.), Bartonella and Afipia species emphasizing Bartonella henselae . Karger, Basel, Switzerland). The U.S. Public Health Service and the Infectious Diseases Society of America has recognized the risk of contracting Bartonellosis, especially in immunocompromised HIV-1 infected individuals, and have published suggested guidelines for cat ownership as feline-to-human transmission of Bartonella henselae is the most commonly recognized route (Kaplan, J. E., H. Masur, and K. K. Holmes. 2002. Guidelines for preventing opportunistic infections among HIV-infected persons—2002. Recommendations of the U.S. Public Health Service and the Infectious Diseases Society of America. MMWR Recomm. Rep. 51:1-52).
[0009] Bartonella spp. also have been found in 39% of deer ticks (species: Ixodes scapularis ) (Adelson, M. E., R. S. Rao, R. C. Tilton, K. Cabets, E. Eskow, L. Fein, J. C. Occi, and E. Mordechai. 2004. Prevalence of Borrelia burgdorferi, Bartonella spp., Babesia microti , and Anaplasma phagocytophila in Ixodes scapularis ticks collected in Northern New Jersey. J. Clin. Microbiol. 42:2799-801). This information, in conjunction with a clinical case study in which patients were co-infected with Borrelia burgdorferi , the causative agent of Lyme Disease, and Bartonella henselae , suggests that tick bites may serve as an additional method of Bartonella henselae transmission (Eskow, E., R. V. Rao, and E. Mordechai. 2001. Concurrent infection of the central nervous system by Borrelia burgdorferi and Bartonella henselae : evidence for a novel tick-borne disease complex. Arch. Neurol. 58:1357-63).
[0010] Current clinical diagnostics rely on culturing, immunofluorescence assay (“IFA”), and polymerase chain reaction (“PCR”) technologies. The culturing of Bartonella from blood samples is technically challenging and is a low-yield procedure. Recommended growth conditions include lengthy incubation periods of at least twenty-one days on Columbia blood agar plates (Raoult, D., and R. Tilton. 1999. Dictionary of Infectious Diseases. Elsevier Publishing, New York; Spach, D. H., and J. E. Koehler. 1998. Bartonella -associated infections. Infect. Dis. Clin. North. Am. 12:137-55). Culturing of Bartonella is therefore not considered an effective and reproducible diagnostic procedure to detect Bartonella spp. infections.
[0011] Bartonella henselae IFAs have high sensitivity and specificity. However, cross-reactivity with other human pathogens, including Coxiella burnetii, Chlamydia spp., Rickettsia rickettsii, Ehrlichia chaffeensis, Treponema pallidum, Francisella tularensis , and Mycoplasma pneumoniae has been reported (Cooper, M. D., M. R. Hollingdale, J. W. Vinson, and J. Costa. 1976. A passive hemagglutination test for diagnosis of trench fever due to Rochalimaea quintana . J. Infect. Dis. 134:605-9; Drancourt, M., J. L. Mainardi, P. Brouqui, F. Vandenesch, A. Carta, F. Lehnert, J. Etienne, F. Goldstein, J. Acar, and D. Raoult. 1995. Bartonella ( Rochalimaea ) quintana endocarditis in three homeless men. N. Engl. 3. Med. 332:41923; McGill, S. L., R. L. Regnery, and K. L. Karem. 1998. Characterization of human immunoglobulin (Ig) isotype and IgG subclass response to Bartonella henselae infection. Infect. Immun. 66:5915-20). In addition, IFAs rely heavily on technicians for the determination of test results which introduces subjectivity into the interpretation of these test results, are time-consuming to score, and require expensive fluorescent microscopes.
[0012] Bartonella PCR amplifies the 16S rRNA gene which permits the simultaneous detection of DNA from Bartonella henselae, Bartonella quintana, Bartonella bacilliformis, Bartonella elizabethae , and Bartonella clarridgeiae (Bergmans, A. M., J. W. Groothedde, 3. F. Schellekens, J. D. van Embden, J. M. Ossewaarde, and L. M. Schouls. 1995. Etiology of cat scratch disease: comparison of polymerase chain reaction detection of Bartonella (formerly Rochalimaea ) and Afipia felis DNA with serology and skin tests. J. Infect. Dis. 171:916-23). While allowing for species-specific identification, PCR requires the presence of Bartonella organisms or DNA in the tested sample.
[0013] The antibody response to Bartonella henselae has been studied in several different types of mammals; however, in order to develop sensitive and accurate serological assays, for example, the human antibody response to Bartonella henselae needs to be elucidated in detail. Identification of antigenic proteins, particularly, is of paramount importance to the creation of improved clinical diagnostics.
BRIEF SUMMARY OF THE INVENTION
[0014] The present invention provides the antigenic proteins noted in the preceding paragraph, wherein these proteins are useful, for example, in immunoassays capable of detecting antibodies specific to Bartonella henselae.
[0015] More specifically, the present invention is directed to an isolated antibody capable of binding to an antigen, wherein the antigen consists of the amino acid sequence of SEQ ID NO:11, SEQ ID NO:12, SEQ ID NO:13, SEQ ID NO:14, SEQ ID NO:15, SEQ ID NO:16, SEQ ID NO:17, or SEQ ID NO:18. In an embodiment, the antibody is human. In another embodiment, the antibody is polyclonal.
[0016] The present invention also is drawn to a kit containing (a) an isolated antigen comprising the amino acid sequence of SEQ ID NO:11, SEQ ID NO:12, SEQ ID NO:13, SEQ ID NO:14, SEQ ID NO:15, SEQ ID NO:16, SEQ ID NO:17, or SEQ ID NO:18 and (b) the reagents necessary for conducting an immunoassay, wherein the immunoassay is capable of detecting the presence of an antibody in a sample, wherein the antibody is capable of binding to an antigen consisting of the amino, acid sequence of SEQ ID NO:11, SEQ ID NO:12, SEQ ID NO:13, SEQ ID NO:14, SEQ ID NO:15, SEQ ID NO:16, SEQ ID NO:17 or SEQ ID NO:18. In an embodiment, the immunoassay is an IFA. In another embodiment, the immunoassay is an enzyme-linked immunosorbent assay (“ELISA”). In yet another embodiment, the isolated antigen in (a) consists of the amino acid sequence of SEQ ID NO:11, SEQ ID NO:12, SEQ ID NO:13, SEQ ID NO:14, SEQ ID NO:15, SEQ ID NO:16, SEQ ID NO:17 or SEQ ID NO:18.
[0017] The present invention also relates to a method for determining whether a subject contains an antibody capable of binding to an antigen consisting of the amino acid sequence of SEQ ID NO:11, SEQ ID NO:12, SEQ ID NO:13, SEQ ID NO:14, SEQ ID NO:15, SEQ ID NO:16, SEQ ID NO:17, or SEQ ID NO:18 comprising (a) conducting an immunoassay on a sample from the subject, and (b) determining that the subject contains the antibody if the results of the immunoassay indicate that the antibody is present in the sample, or determining that the subject does not contain the antibody if the results of the immunoassay indicate that the antibody is not present in the sample. In an embodiment, the subject is human. In another embodiment, the immunoassay is an IFA. In yet another embodiment, the immunoassay is an ELISA.
[0018] The present invention also pertains to a method for determining whether a subject has an increased likelihood of being infected presently or in the past with Bartonella henselae comprising (a) conducting an immunoassay on a sample from the subject, and (b) determining that the subject has an increased likelihood of being infected presently or in the past with Bartonella henselae if the results of the immunoassay indicate that an antibody is present in the sample, or determining that the subject does not have an increased likelihood of being infected presently or in the past with Bartonella henselae if the results of the immunoassay indicate that the antibody is not present in the sample, wherein the antibody is capable of binding to an antigen consisting of the amino acid sequence of SEQ ID NO:11, SEQ ID NO:12, SEQ ID NO:13, SEQ ID NO:14, SEQ ID NO:15, SEQ ID NO:16, SEQ ID NO:17 or SEQ ID NO:18. In an embodiment, the subject is human. In another embodiment, the immunoassay is an IFA. In yet another embodiment, the immunoassay is an ELISA.
[0019] The present invention also is drawn to a method for determining whether a subject has a present infection with Bartonella henselae or had a past infection with Bartonella henselae comprising (a) conducting an immunoassay on a sample from the subject, and (b) determining that the subject has a present infection with Bartonella henselae or had a past infection with Bartonella henselae if the results of the immunoassay indicate that an antibody is present in the sample, or determining that the subject does not have a present infection with Bartonella henselae or did not have a past infection with Bartonella henselae if the results of the immunoassay indicate that the antibody is not present in the sample, wherein the antibody is capable of binding to an antigen consisting of the amino acid sequence of SEQ ID NO:11, SEQ ID NO:12, SEQ ID NO:13, SEQ ID NO:14, SEQ ID NO:15, SEQ ID NO:16, SEQ ID NO:17, or SEQ ID NO:18. In an embodiment, the subject is human. In another embodiment, the immunoassay is an IFA. In yet another embodiment, the immunoassay is an ELISA.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] FIG. 1 illustrates a two-dimensional analysis of proteins of Bartonella henselae . Soluble (A), less soluble (B), and insoluble (C) proteins derived from Bartonella henselae were separated based on isoelectric point (pI 5-8) and molecular weight. Gels were stained with Coomassie Blue. The soluble fractions were also separated using a larger pI range (3-10) (D) to visualize the majority of proteins found in Bartonella henselae.
[0021] FIG. 2 illustrates the reactivity of patient serum (A) and normal serum (B) to the soluble fraction of Bartonella henselae . Western blots shown are representative blots of fourteen patient sera and seven normal sera.
[0022] FIG. 3 illustrates the localization of Bartonella henselae proteins selected for further analysis. Coomassie-Blue stained two-dimensional SDS-PAGE gel with spots yielding greater than 63% reactivity to patient sera are circled and given an arbitrary letter designation for future reference.
[0023] FIG. 4 illustrates a Coomassie-Blue stained gel of purified recombinant proteins. One μg of each of recombinant GroEL, recombinant GroES, recombinant BepA, recombinant RpIL, and recombinant SodB were run on a 15% SDS-PAGE gel and stained with Coomassie Blue to demonstrate purity of these recombinant proteins. In the figure, the symbol “r” stands for the word “recombinant.”
[0024] FIG. 5 illustrates serum IgG reactivity to recombinant GroEL, recombinant SodB, recombinant BepA, recombinant RpIL, and recombinant GroES. These proteins were mixed in equal concentrations, and loaded into each lane of a 15% SDS-PAGE gel. After transfer, membranes were exposed to either patient sera (P) or normal sera (N). Bound antibodies were detected with anti-human IgG-horse-radish peroxidase (“HRP”). Blots shown are representative. In the figure, the symbol “r” stands for the word “recombinant.”
[0025] FIG. 6 illustrates human serum IgG reactivity to recombinant GroEL, recombinant RpIL, and recombinant 17 kDa antigen. Recombinant GroEL, recombinant RpIL, and recombinant 17 kDa antigen were mixed in equal concentrations, and loaded into each lane of a 15% SDS-PAGE gel. After transfer, membranes were exposed to either patient sera (P) or normal sera (N). Bound antibodies were detected with antihuman IgG-HRP. Blots shown are representative. In the figure, the symbol “r” stands for the word “recombinant.”
[0026] FIG. 7 illustrates a reactive epitope of RpIL. Recombinant RpIL was digested overnight with endoproteinase Arg-C. rRpIL that had not undergone digestion (−) and rRpIL that had (+) were loaded in equal amounts onto a 16.5% Tris-Tricine gel (A). After transfer, membranes were exposed to either patient sera (P) or normal sera (N). Bound antibodies were detected with anti-human IgG-HRP (B). Blots shown are representative.
DETAILED DESCRIPTION
[0027] The following examples illustrate the discovery that the GroES protein, the RpIL protein, the BepA protein, the GroEL protein, the SodB protein, the UbiG protein, and the ABC transporter protein produced by Bartonella henselae are each antigenic. Each of these antigens can be used in an immunoassay to determine whether a subject possesses an antibody that binds to it. These examples are set forth by way of illustration only, and nothing therein shall be taken as a limitation upon the overall scope of the invention.
[0028] Techniques applicable to the present invention are described in Short Protocols in Molecular Biology, 5 th edition, Volumes 1 and 2, 2002, Edited by Frederick M. Ausubel et al., John Wiley & Sons, Inc., Hoboken, N.J., the entire contents of which are hereby incorporated by reference; Short Protocols in Molecular Biology, 3 rd edition, 1997, Edited by Frederick M. Ausubel et al., John Wiley & Sons, Inc., New York, N.Y., the entire contents of which are hereby incorporated by reference; Short Protocols in Immunology, 2005, Edited by John E. Coligan et al., John Wiley & Sons, Hoboken, N.J., the entire contents of which are hereby incorporated by reference; and The Immunoassay Handbook, 3 rd Edition, 2005, Edited by David Wild, Elsevier, Amsterdam, San Diego, Calif., Oxford, the entire contents of which are hereby incorporated by reference.
Example 1
Bartonella henselae Proteome
[0029] Bartonella henselae proteins were isolated from cultures of Bartonella henselae Houston-1 . Bartonella henselae was grown to an optical density of 0.3 in 200 ml of BBH-H media at 37° C., shaking at 180 rpm, for five days (Chenoweth, M. R., G. A. Somerville, D. C. Krause, K. L. O'Reilly, and F. C. Gherardini. 2004. Growth characteristics of Bartonella henselae in a novel liquid medium: primary isolation, growth phase-dependent phage induction, and metabolic studies. Appl. Environ. Microbiol. 70:656-63). The presence of Bartonella henselae in the culture was verified by an in-house PCR developed against the Bartonella henselae 16S rRNA. Culture pellets obtained by centrifugation were resuspended in PBS and sonicated. The soluble fraction was desalted using a desalting kit (BioRad, Hercules, Calif.) and resuspended in 8 M urea, 2% CHAPS, 40 mM DTT, 0.2% Bio-Lyte 3/10 ampholyte. The protein concentration was determined by a reducing agent-compatible detergent-compatible (“RC DC”) assay (BioRad, Hercules, Calif.).
[0030] Three different protein fractions were obtained based on protein solubilities. Fraction 1 contained proteins with the highest solubility and 2-3 times the amount of protein isolated in fraction 2, which contained proteins of intermediate solubility. Fraction 3 contained proteins less soluble than those in fraction 2 and yielded 2-3 times less protein than that isolated in fraction 2.
[0031] Proteins from each fraction were separated by two-dimensional electrophoresis. 180 μg of protein were loaded onto pH 3-10 immobilized pH gradient (“IPG”) strips (BioRad, Hercules, Calif.) during overnight passive gel rehydration. Isoelectric Focusing (“IEF”) was performed under standard conditions. Focused IEF strips were equilibrated for 15 minutes in 6 M urea, 2% SDS, 0.05 M Tris/HCI, 20% glycerol, 2% DTT and then 15 minutes in 6 M urea, 2% SDS, 0.05 M Tris/HCI, 20% glycerol, 2.5% iodoacetamide and then overlayed onto a 8-15% gradient SDS-PAGE gel (BioRad, Hercules, Calif.). The gels were run for 65 minutes at 200V.
[0032] Separations utilized a narrow pH range (5-8) and demonstrated a decrease in the number of proteins concomitant with a decrease in solubility. Computer analysis using PDQuest™ (BioRad, Hercules, Calif.) identified over 900 protein spots in fraction 1, 358 spots in fraction 2, and 138 spots in fraction 3 ( FIG. 1A-C ). Fraction 1 required minimal processing and smaller amounts of Bartonella henselae culture to prepare and still yielded a significant number of spots. Hence, fraction 1 was pursued further in these studies. Use of IPG strips with a pH 3-10 resulted in an increase in the number of proteins observed in fraction 1 to more than 1000 spots ( FIG. 1D ).
[0033] Spots of interest were excised from Coomassie-Blue stained gels and sent for Matrix Assisted Laser Desorption Ionization Mass Spectrometry “MALDI-MS” peptide fingerprinting. This resulted in identification of proteins of interest. The genes encoding these proteins were subsequently amplified from Bartonella henselae DNA and ligated into a pET30 Ek/LIC expression vector (EMD Biosciences, San Diego, Calif.) (Table 1). Protein expression by transformed DH5α cells was induced using the Overnight Express™ AutoInduction System (EMD Biosciences, San Diego, Calif.). Proteins were purified by two passages over a nickelnitrilotriacetic acid (“Ni-NTA”) resin column (EMD Biosciences, San Diego, Calif.). After completion of buffer exchange into PBS, the proteins were concentrated. Final protein concentrations were determined by bicinchoninic acid (“BCA”) assay.
[0000]
TABLE 1
Primers used for cloning of Bartonella henselae
genetic material into the pET3OEK/LIC vector.
Protein
Forward Primer
Reverse Primer
GroEL
5′-GACGACGACAAGATGGCT
5′-GAGGAGAAGCCCGGTTT
GCTAAAGAAGTGAAGTTTGG
AGAAGTCCATGCCGCCCA-3′
C-3′
(SEQ ID NO: 2)
(SEQ ID NO: 1)
GroES
5′-GACGACGACAAGATGGCT
5′-GAGGAGAAGCCCGGTTA
AACATACAAT-3′
ACCCAAAATCCCCATAA-3′
(SEQ ID NO: 3)
(SEQ ID NO: 4)
BepA
5′-GACGACGACAAGATGAT
5′-GAGGAGAAGCCCGGTT
AAGAAAAACAGTTCCCAA-3′
TAGCCTTTTAGGGTTT-3′
(SEQ ID NO: 5)
(SEQ ID NO: 6)
RpIL
5′-GACGACGACAAGATGGCT
5′-GAGGAGAAGCCCGGTTT
GATCTAGCGAAGA-3′
ATTTAAGTTCAACTTTAGC
(SEQ ID NO: 7)
A-3′
(SEQ ID NO: 8)
SodB
5′-GACGACGACAAGATGGCT
5′-GAGGAGAAGCCCGGTTT
TTTGAACTAGCACCTT-3′
AAAGTCCGCAATCTTCAT
(SEQ ID NO: 9)
A-3′
(SEQ ID NO: 10)
Example 2
Reactivity of Patient Sera to Bartonella henselae Soluble Proteins
[0034] In order to determine which Bartonella henselae proteins can bind to antibodies, Western blots were performed using a two-dimensional map of fraction 1 using patient and normal human sera. Bartonella henselae IFA positive and negative human serum samples were purchased from Dr. D. Raoult (Universite de la Mediterranee, France) and from Focus Diagnostics (Cypress, Calif.). Serum samples with Bartonella henselae WA titers 1:64 were considered positive sera, samples with IFA titers <1:64 were considered negative sera. All serum samples were verified in-house by IFA (Focus Diagnostics, Cypress, Calif.) prior to use.
[0035] Western blotting was performed using a standard protocol. Briefly, proteins were electrophoretically transferred from SDS-PAGE gels onto polyvinyldine difluoride (“PVDF”) membranes. Transfer was performed at 100V for 60 minutes. After transfer, the membranes were stained with RedAlert™ (EMD Biosciences, San Diego, Calif.). The membranes were washed in PBS-Tween 20 and exposed to a 1:500 dilution of either normal or patient sera diluted in 1% bovine serum albumin (BSA)-PBS-Tween 20 for one hour. After washing of the membrane, anti-human IgG-HRP (KPL, Gaithersburg, Md.) was added at a dilution of 1:2000 in 1% BSA-PBS-Tween 20. 0.5 mg/ml 3,3′-diaminobenzidine (DAB; Sigma, St. Louis, Mo.) was then added. After exposure to substrate, the blots were imaged and analyzed by the software package PDQuest™.
[0036] Analysis of fourteen patient ( Bartonella henselae IFA-positive) sera revealed reactivity to many Bartonella henselae proteins ( FIG. 2A ). In contrast, the seven normal ( Bartonella henselae IFA-negative) sera tested demonstrated minimal reactivity to Bartonella henselae spots ( FIG. 2B ). Surprisingly, comparison of spot reactivities by PDQuest™ between all patient sera tested demonstrated no common protein reactivity between all samples. However, at least seven spots demonstrated reactivity to greater than 64% of the patient sera tested ( FIG. 3 and Table 2). These spots reacted to 0-14% of the normal sera tested (Table 2).
[0000]
TABLE 2
Reactivity of patient ( Bartonella henselae IFA positive) and
normal ( Bartonella henselae IFA negative) sera to noted spots.
Spot
Patient Sera
Normal Sera
Designation
(% reactivity)
(% reactivity)
A
10/14 (71%)
1/7 (14%)
B
12/14 (86%)
1/7 (14%)
E
9/14 (64%)
0/7 (0%)
F
9/14 (64%)
0/7 (0%)
G
9/14 (64%)
0/7 (0%)
H
10/14 (71%)
1/7 (14%)
J
9/14 (64%)
1/7 (14%)
Example 3
Identification of Reactive Spots
[0037] Protein spots were excised from a Coomassie-Blue stained gel, and subjected to trypsin digestion and identification by MALDI-MS. Comparison of the molecular weights of the resultant trypsin fragments to the expected molecular weights of the digestion products from the Bartonella henselae genome sequence revealed the identities of these proteins (Table 3). Spot A was identified as GroES, a chaperonin. Spot B was identified as RpIL, the L7/L12 segment of the 50S ribosome subunit. Spots E and F were identified as BepA, which has an unknown function. Spot G was identified as GroEL, a heat shock protein. Spot H was identified as SodB, a superoxide dismutase, and also was identified as UbiG, a chaperonin and a heat shock protein. Spot J was identified as the ABC transporter.
[0000]
TABLE 3
Properties of identified proteins.
Spot
Accession
MW
Gene Size
Putative
SEQ ID
Designation
Protein
No.
(kDa)
pI
(bp)
Function
NO:
A
GroES
49476035
10.7
5.23
297
chaperonin
11
B
RpIL
49475397
12.7
4.61
369
50S ribosomal
12
protein L7/L12
E, F
BepA
49476039
19.7
6.15
525
unknown
13
G
GroEL
6226790
57.6
4.91
1644
chaperonin, heat
14
shock protein
H
SodB
49475260
23.1
5.75
600
superoxide
15
dismutase
H
UbiG
49475201
28
7.35
741
3-dimethyl
16
ubiquinone-93-
methyltrans-
ferase
J
ABC
49475425
28.2
5.41
750
periplasmic
17
Trans-
amino acid-
porter
binding protein
[0038] The amino acid sequence of each of the GroES, RpIL, BepA, GroEL, SodB, UbiG, and the ABC transporter proteins was previously published (see Table 3 for the respective accession numbers). The gene encoding each of the GroEL, GroES, BepA, RpIL, and SodB proteins was cloned and expressed with an N-terminal histidine tag that allowed for purification over an Ni 2+ column. After purification, protein fractions were run on an SDS-PAGE gel which revealed an estimated purity of greater than 90% for each protein isolated ( FIG. 4 ).
Example 4
Western Analysis of Patient Sera to Select Bartonella henselae Proteins
[0039] Western analysis of two-dimensional gels revealed the overall reactivity of patient sera to Bartonella henselae suggesting five proteins for further study (GroES, GroEL, SodB, RpIL, and BepA). In order to determine the reactivity of sera to these proteins, recombinant GroES, recombinant GroEL, recombinant SodB, recombinant RpIL, and recombinant BepA were simultaneously separated by one-dimensional SDS-PAGE gels and subsequently electrophoretically transferred to PVDF membranes. Individual lanes containing all of the chosen proteins were screened with either patient or normal sera ( FIG. 5 ). Patient sera demonstrated reactivity to all proteins in various combinations. However, normal serum demonstrated recognition of recombinant SodB and recombinant BepA. Recombinant SodB and recombinant BepA were not analyzed further due to this reactivity.
[0040] A subsequent Western blot was produced that combined recombinant GroEL, recombinant RpIL, and the recombinant 17 kDa protein. The 17 kDa protein has been previously used in an ELISA to determine if patients have an antibody response to Bartonella henselae ; although normal sera did not demonstrate greater than background reactivity to the 17 kDa protein, not all patient sera contain antibodies to this protein (Loa, C. C., E. Mordechai, R. C. Tilton, and M. E. 2006. Adelson. Production of recombinant Bartonella henselae 17 kDa protein for antibody-capture ELISA. Diagnostic Microbiology and Infectious Disease. In Press). Utilization of recombinant GroEL, recombinant RpIL and recombinant 17 kDa protein in combination resulted in recognition of at least one band by twenty-four of twenty-eight patient sera and seven of twenty-one normal sera ( FIG. 6 ). Thus, this Western blot has a sensitivity of 85.7% and a specificity of 66.7%.
Example 5
Proteolytic and Chemical Digestion of RpIL
[0041] In an effort to localize the immunodominant and cross-reactive regions of RpIL and impart increased specificity to the Western blot assay, digestions of recombinant RpIL were performed. Recombinant RpIL (18 μg) was digested with 29 μg 3-bromo-2-(2-nitrophenylsulfenyl)skatol (“BNPS-skatol”) (MP Biomedicals, Irvine, Calif.) in 100% acetic acid overnight at 47° C. The reaction was stopped by the addition of 24 μl of ddH2O. Recombinant RpIL (55 μg) was incubated with 1 μg endoproteinase Arg-C (Calbiochem, San Diego, Calif.), activation solution (5 mM DTT, 0.5 mM EDTA) and incubation solution (0.1 M Tris HCI, 0.01 M CaCl 2 ). The reaction was incubated overnight at 37° C.
[0042] Based on sequence analysis, chemical digestion with BNPS-skatol cleaves recombinant RpIL at one site (after the amino acid residue at position 73) resulting in fragments of approximately 8200 and 9400 Da in size. Proteolytic digestion with endoproteinase Arg-C results in cleavage at three sites (after the amino acid residues at positions 14, 28, and 119) resulting in fragments of approximately 1700, 1500, 9500, and 4900 Da in size. Recombinant RpIL was digested using these two methods, which resulted in fragments of the appropriate size (data not shown). Subsequent Western analysis was performed utilizing patient and normal human sera ( FIG. 7 ). Cleavage with BNPS-skatol did not provide any additional evidence for the localization of epitopes. However, patient sera appeared to bind most frequently to an approximately 10 kDa fragment that resulted from endoproteinase Arg-C digestion of rRpIL (see SEQ ID NO:18 for the amino acid sequence of this 10 kDa fragment). Ten of eleven patient sera bound to a 10 kDa digestion product, while three of twelve normal sera bound.
Example 6
ELISA Analysis
[0043] In order to provide a semi-quantitative result, ELISAs using recombinant proteins as the solid phase were developed. Purified proteins diluted in coating buffer (0.015 M Na 2 CO 3 , 0.035 M NaHCO 3 (pH 9.6)) were used to coat 96-well Immulon 2 high-binding plates (DYNEX Technologies, Chantilly, Va.). Recombinant GroES, recombinant GroEL, recombinant RpIL, and recombinant BepA were used at 0.25, 0.25, 0.01, and 2 μg/ml, respectively, to coat plates. After overnight incubation at 4° C., the plates were washed with PBS-Tween 20, blocked with 1% BSA for one hour at 37° C., and washed again. Dilutions of serum in 1% bovine serum albumin were added and then incubated for one hour at 37° C. Antigen-specific antibodies were detected by goat anti-human IgG-HRP (KPL, Gaithersburg, Md.) and developed with 3,3′,5,5′-tetramethylbenzidine (“TMB”) (Moss, Pasadena, Md.) for fifteen minutes. The reaction was stopped with 1N HCI and the absorbance at 450 nm was recorded after a standardized period of ten minutes.
[0044] An ELISA using recombinant RpIL as the coating antigen demonstrated reactivity to fourteen of eighteen patient sera and seven of seventeen normal sera. This ELISA exhibited a sensitivity of 78% and a specificity of 59% (Table 4). Sixteen of twenty patient sera and fourteen of twenty normal sera demonstrated reactivity by recombinant GroEL ELISA. Recombinant GroES ELISA demonstrated reactivity with sixteen of twenty patient sera and seventeen of twenty normal sera. An ELISA using recombinant BepA as the coating antigen demonstrated reactivity to twelve of fourteen patient sera and five of nine normal sera. Sensitivities and specificities of ELISAs based on these proteins were determined (Table 4).
[0000]
TABLE 4
Sensitivities and specificities of ELISAs using
various recombinant proteins as coating antigens.
Recombinant Protein
Sensitivity (%)
Specificity (%)
recombinant GroES
80
15
recombinant RpIL
78
59
recombinant BepA
86
44
recombinant GroEL
80
30 | Disclosed are antibodies that bind to the antigenic proteins GroES, RpIL, GroEL, SodB, UbiG, the ABC transporter, and an expressed antigenic protein of unknown function (the “BepA” protein) of Bartonella henselae , and use of these antigenic proteins in immunoassays in order to determine whether a sample from a subject contains one or more of these antibodies. Presence of such an antibody in the subject indicates that the subject is or was infected with Bartonella henselae , or indicates that the subject has an increased likelihood of being infected presently or in the past with Bartonella henselae . Also disclosed are kits for performing immunoassays, wherein each kit contains one or more of these antigenic proteins and also contains the reagents necessary for conducting an immunoassay. | 6 |
This application is a Continuation of application Ser. No. 08/145,308, filed on Nov. 3, 1993, now abandoned, which is a continuation application of Ser. No. 07/677,762, filed on Mar. 29, 1991, now abandoned.
BACKGROUND OF THE INVENTION
1. Field Of the Invention
The present invention relates generally to non-volatile semiconductor memories and, more particularly, to electrically erasable programmable read-only memory devices of large capacity.
2. Description of the Related Art
With the increasing needs for high performance and high reliability of digital computer systems, it has been strongly required to develop a rewritable semiconductor memory having a memory capacity which is so large that the memory can be used instead of an existing external data storing medium such as a magnetic disk or a fixed disk unit (which is sometimes called a "hard disk device") used for a computer.
Recently, in order to meet the above requirement, an electrically erasable programmable non-volatile read-only memory (hereinafter referred to as an "EEPROM" according to the custom of this technical field) in which the memory integration density is enhanced by reducing the number of transistors used in each memory section on a chip substrate with limited size has been proposed and developed.
This type of EEPROM is typically called a "NAND type EEPROM" in which series circuits of floating gate type metal oxide semiconductor field effect transistors (referred to as "MOSFETs" hereinafter) are connected to a corresponding bit line via a switching transistor. The switching transistor is rendered conductive when designated to selectively connect the series array of floating gate type MOSFETs to a corresponding bit line associated therewith, and is generally called a "select transistor."
Each of the series-arrayed floating gate type MOSFETs is a minimum element for storing data and may be considered to correspond to a memory cell of a conventional dynamic random access memories, that is, DRAMs (of course, the series array of MOSFETs itself is sometimes called a "memory cell." The naming is not particularly important. For example, in this patent specification, each series array of MOSFETs will be named as a "NAND cell unit"). In general, each transistor array consists of four, eight or sixteen floating gate type MOSFETs. Each MOSFET has a control gate connected to a corresponding word line and a floating gate for storing charges representing logic data of "1" or "0." Since each memory cell can be formed of one floating gate type MOSFET, the integration density of the EEPROM can be enhanced and therefore the memory capacity thereof can be increased.
In the above NAND type EEPROM, data is sequentially written into the floating gate type MOSFETs, that is, memory cell transistors in each NAND cell unit. In a case where logic data is written into the EEPROM at a desired memory address, that is, into a selected one of the floating gate type MOSFETs of the designated NAND cell unit, a high voltage Vpp of 20 volts, for example, and an intermediate voltage Vppm, which has a potential level between the power source voltage Vcc of the EEPROM and the high voltage Vpp and is typically set at 10 volts when the power source voltage Vcc is 5 volts, are used as follows. The high voltage Vpp is applied to the control gate electrode of a selected memory cell transistor and the intermediate voltage Vppm is applied to the control gate electrodes of non-selected memory cell transistors lying between the selected memory cell transistor and the select transistor. The non-selected memory cell transistors are rendered conductive.
Under such condition, when a voltage of 0 volts is applied to a corresponding bit line as a data voltage representing a logic data value, the data voltage is transmitted to a target memory cell, that is, to the drain of the selected floating gate type MOSFET via the non-selected memory cell transistors which are rendered conductive. Therefore, in the MOSFET, electrons are injected by the tunnel effect from the drain into the floating gate electrode thereof. As a result, the threshold value of the MOSFET is shifted in a positive direction. Thus, logic data "1" is stored into a desired address location.
When the intermediate voltage Vppm is applied to the bit line, injection of electrons will not occur in the selected floating gate type MOSFET. In this case, the threshold value of the MOSFET is kept unchanged. This state is defined as a logic "0" storing state. The operation of erasing data in the NAND cell type EEPROM is simultaneously effected for all of memory cells of the NAND type memory cell units. This is so-called "simultaneous erasing." At this time, all of the NAND cell units of the EEPROM are electrically separated from the bit lines, substrate and source voltage. The control gate electrodes of all of the memory cell transistors are set at 0 volts and the substrate voltage (and the well potential if the NAND cell units are formed in a well region) is set to the high voltage Vpp. As a result, in all of the memory cell transistors, electrons are moved from the floating gate electrodes thereof to the substrate (or the well region). The threshold values thereof are shifted in a negative direction. The stored data items are electrically erased at the same time.
In order to selectively read out stored data of a specified memory cell transistor, 0 volts is applied to the control gate electrode of the selected memory cell transistor. The control gate electrodes of the remaining memory cell transistors in the selected NAND cell unit are set to the power source voltage Vcc (=5 volts). The select transistors in the selected NAND cell unit are rendered conductive by application of the power source voltage Vcc to the gate electrodes thereof. The logic value of the stored data can be determined by checking whether or not current flows in a common source line which is also associated with the specified NAND cell unit including the selected memory cell transistor. In the above data write-in or programming mode, those of the non-selected memory cell transistors of each NAND cell unit which lie between the target memory cell transistor and the select transistor function as "transfer gates" for transferring a logic data voltage to the selected memory cell transistor. It may be considered that the non-selected memory cell transistors also function as transfer gates for transferring readout data in the data readout mode.
To keep the data transferring efficiency high, the threshold voltages (the voltages representing the threshold values) of the memory cell transistors serving as the transfer gates are required to be always set within a properly defined range. For instance, the threshold voltage of the memory cell transistors in which a logic "1" data has been written is preferably maintained in a specific potential value ranging from 0.5 to 3.5 volts. In addition, the EEPROM comes with variation in the power source voltage itself, variation in quality caused in the manufacturing process and/or aging variation or deterioration in the physical property of the EEPROM under various application environments--especially, temperature--for the end users. Taking such fact into consideration, it would be desirable to design a range narrower than the above range so as to add a safety margin. Otherwise, the high operation reliability will no longer be expected for the NAND cell type EEPROMs.
With a conventional data programming scheme, it is difficult to precisely control variation in the threshold voltages of data-programmed memory cell transistors so as to fall within the allowable range. The data programming characteristic of each memory cell transistor tends to be varied in accordance with the aforementioned parameters. Even when the data-programming is executed under the same data write condition, the NAND cell units are not identical with one another in their data writing properties such that "difficult-to-write" as well as "easy-to-write" memory cell transistors will appear, in the EEPROM. Conventionally, time length management is applied to cause the data writing time to be simply lengthened so as to compensate for the above variation in the threshold voltages among the memory cell transistors. With such a time management, however, while the data-writing at the "difficult-to-write" cells can be made successfully, the "easy-to-write" cells are forced to be in what is called the "over-write" condition. As a result, the threshold voltages of such cells will go far beyond the allowable range.
SUMMARY OF THE INVENTION
It is therefore an object of the present invention to provide a new and improved electrically erasable programmable semiconductor memory device which is excellent in operation reliability.
In accordance with the above object, the present invention is drawn to an electrically erasable non-volatile semiconductor memory device which comprises a semiconductive substrate, parallel data transfer lines arranged on the substrate, and parallel control gate lines provided on the substrate to insulatively intersect the data transfer lines so as to define intersections therebetween.
Metal insulator semiconductor field effect transistors are arranged at the intersections as memory cell transistors. Each memory cell transistor has a control gate electrode and an electrically floating gate electrode for charge storage, and is connected at its control gate electrode to a corresponding one of the control gate lines. The memory cell transistors are arranged in a plurality of cell units each of which has a preselected number of series-connected memory cell transistors having a first end connected to a corresponding one of the data transfer lines and a second end connected to a common source line together with others of the series-connected memory cell transistors.
A data write controller is provided connected to the memory cell transistors, for, when a memory cell transistor is selected in one of the cell units in a data programming mode, selectively applying the gate electrode of the selected transistor with a biasing voltage of a preselected potential level, for verifying an electrical data write condition of the selected 10 memory cell transistor after a data was electrically written into the selected memory cell transistor, and for performing, when the verified write condition is dissatisfied, a data re-writing operation so as to apply the selected memory cell transistor with an additional write-in voltage which compensates for the dissatisfaction of the verified write condition in the selected memory cell transistor.
The foregoing and other objects, features and advantages of the invention will become more apparent in the detail description of preferred embodiments presented below.
BRIEF DESCRIPTION OF THE DRAWINGS
In the detailed description of a preferred embodiments of the present invention presented below, reference is made to the accompanying drawings in which:
FIG. 1 is a diagram showing the main structure of a NAND cell type EEPROM in accordance with one preferred embodiment of the present invention;
FIG. 2 is a diagram showing the circuit configuration of a memory array section of the EEPROM shown in FIG. 1;
FIG. 3 is a diagram showing the plan view of one of NAND cell units defined in the memory array section of FIG. 2;
FIG. 4 is a diagram showing the enlarged sectional view of a memory cell transistor of the NAND cell unit taken along the line IV--IV of FIG. 3;
FIG. 5 is a diagram showing another enlarged sectional view of the memory cell transistor of the NAND cell unit along the line V--V of FIG. 3;
FIG. 6 is a diagram showing a detailed circuit configuration of the main circuit components of the embodiment shown in FIG. 1;
FIG. 7 is a diagram showing a detailed configuration of a control-gate control circuit shown in FIG. 1;
FIG. 8 is a diagram showing a detailed configuration of a verify-voltage generation circuit to be provided in the embodiment shown in FIG. 1;
FIG. 9 is a diagram showing a detailed configuration of a verify-termination detector shown in FIG. 1;
FIG. 10 is a diagram showing a timing chart of main voltage signals to be generated in the main portions of the embodiment shown in FIG. 1;
FIG. 11 is a diagram showing the main structure of a NAND cell type EEPROM in accordance with another embodiment of the present invention;
FIGS. 12A and 12B are a diagram showing the overall circuit configuration of a couple of bit line control circuits shown in FIG. 11;
FIGS. 13A and 13B are a diagram showing a timing chart of main signals generated at the main portions of the NAND cell type EEPROM shown in FIG. 11 in a write-verify mode thereof; and
FIG. 14 is a diagram showing a timing chart of main signals generated at the main portions of the NAND cell type EEPROM shown in FIG. 11 in a data read mode of the EEPROM.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to FIG. 1, a NAND cell type electrically erasable programmable read-only memory or EEPROM in accordance with one preferred embodiment of this invention is generally designated by a reference numeral "10." The NAND cell type EEPROM 10 has a main memory array section 12 with an array of memory cells in a matrix form. The memory section 12 includes a previously selected number of memory cell transistors which will be described later in this description.
The memory array section 12 is associated with a control-gate control circuit 14, a data latch circuit 16 and sense amplifier circuit 18. These circuits 16 and 18 are provided for execution of data write and read operations in the EEPROM 10. A column address signal generation circuit 20 is connected to the data latch circuit 16 and the sense amplifier circuit 18.
The column address generator 20 generates a suitable control signal which is required for data write, read, or "write-verify" operations to be carried out in the EEPROM 10. The control signal is supplied to the memory section 12, as will be explained in detail later. When a "write-verify" operation is being performed in a data write mode, the sense amplifier circuit 18 performs a sensing operation in accordance with a column address signal generated by the column address generator 20. The data latch circuit 16 then latches a data to be re-written into a selected memory cell.
The output of the data latch circuit 16 is connected to the first input of a data comparison circuit 22. The output of the sense amplifier circuit 18 is connected to the second input of the data comparator 22. The output of the data comparator 22 is fed back to the data latch circuit 16 via an output buffer circuit 24. The output of the sense amplifier circuit 18 is connected to an input/output (I/O) data buffer circuit 26, which has its output connected to the data latch circuit 16 as shown in FIG. 1. A verify-termination detection circuit 28 is provided which has its input connected to the output buffer circuit 24.
The data comparator 22 compares a write data being latched by the data latch circuit 16 with a data read out by the sense amplifier circuit 18 with respect to every column address, in the verify operation performed during programming. The comparison result is then held or latched temporarily within the data comparator 22.
The output signal of the data comparator 22 indicative of the comparison result is supplied via the output buffer 24 to the verify-termination detection circuit 28. The selected memory cells in the memory array section 12 are subjected to programming, i.e., data writing operation in accordance with data kept in the data latch circuit 16. After such a data writing, a "write-verify" operation is now executed under the control of the control-gate controller 14.
The "write-verify" operation may be defined as an operation of verifying or confirming whether the data voltages that have been actually written into the designated memory cell transistors are distributed so that they fall within a predetermined allowable range, which is normally between 0.5 and 3.5 volts. The verify-termination detector 28 monitors the written data voltages on the basis of the output signal of the data comparator 22. If it is verified that all of them fall within the allowable range, the verify-termination detector 28 generates a certain electrical signal as a "verify-termination signal." Obviously, if even one of the data voltages is out of the allowable range, the verify-termination signal will not be obtained. During such period of time, the data-writing operation is again executed with assistance of the controller 14. Such a "rewriting" will be repeated until when the verify-termination signal is generated by the detector 28.
A description is now given of the internal arrangement of the memory array section 12. As shown in FIG. 2, the NAND cell type EEPROM 10 has parallel data transfer lines BL and parallel address control lines WL in the memory section 12. The address control lines WL insulatively intersect the data transfer lines insulatively arranged on a chip substrate 30 (see FIG. 3). The data transfer lines BL are called "bit lines"; the address control lines WL are called "word lines."
Each bit line BLi (i=1, 2, . . . , n) is connected to series circuits MB of a previously selected number of floating gate type metal oxide semiconductor field effect transistors. In this embodiment, each transistor series circuit MBi consists of eight floating gate type MOSFETs Mi1, Mi2, . . . , Mi8. For example, the transistor series circuit MB1 has floating gate type MOSFETs M11, M12, . . . , M18 as shown in FIG. 2. Each MOSFET Mij (i=1, 2 . . . N; j=1, 2 . . . , 8) functions as a memory cell for storing unit logic data. The series array of eight memory cells is hereinafter referred to as a "NAND cell unit" and the floating gate type MOSFETs M are referred to as "memory cell transistors" or simply "memory cells." The construction of the upper half of the memory cell matrix in FIG. 2 is essentially the same as that described above.
In each NAND cell unit MBi, memory cell transistors Mi1, Mi2, . . . , Mi8 are electrically connected at the control gate electrodes thereof to the word lines WL1, WL2, . . . , WL8, respectively. Each of the NAND cell units MB1, MB2, . . . , MBn is connected to a corresponding bit line BLi via a first single gate type metal oxide semiconductor field effect transistor or MOSFET Qi1. For example, the NAND cell unit MB1 is connected to the bit line BL1 via the MOSFET Q11. The MOSFETs Q1 (=Q11, Q21, . . . , Qn1) are commonly connected at the gate electrodes thereof to a select gate line SG1. Each MOSFET Qil is selectively rendered conductive in response to a voltage signal vsgl supplied to the select gate line SG1 and causes a NAND cell unit MBi associated therewith to be electrically connected to a corresponding bit line BLi. The switching MOSFET Qil is referred to as a "first select transistor."
As shown in FIG. 2, the NAND cell units MB1, MB2, . . . , MBn are commonly connected to a common source potential Vs, which is the same as the ground potential and is 0 volts in this embodiment, via second single gate type MOSFETs Q2 (=Q12, Q22 . . . , Qn2), respectively. For example, in the NAND cell unit MB1, the second MOSFET Q12 is connected between the source electrode of a final-stage memory cell transistor M18 included in the NAND cell unit and the common source potential Vs. The second MOSFETs Q2 are commonly connected at the gates thereof to a second select gate line SG2. Each MOSFET Q12 effects the switching operation in response to a voltage signal Vsg2 supplied to the select gate line SG2, and when it is turned on, it electrically connects the NAND cell unit MBi associated therewith to the common source potential Vs. The switching MOSFET Qi2 is hereinafter referred to as a "second select transistor."
The plan view of eight memory cell transistors M11 to M18 of the NAND cell unit MB1 is shown in FIG. 3. For easy understanding, insulation layers are omitted in FIG. 3. Each memory cell transistor Mlj (j=1, 2, . . . , or 8) has a floating gate electrode 32 insulatively formed over a lightly doped P type (P- type) substrate 30. The floating gate electrode acts as a charge storage means. Each memory cell transistor also has a control gate electrode 34 insulatively formed over the floating gate electrode. In FIG. 3, the underlying floating gate electrode 32 is shown to be wider than the control gate electrode 34; however, this is merely a symbolic illustration. In practice, the width thereof is substantially the same as that of the control gate electrode. The first and second select transistors Q11 and Q12 are arranged on both end portions of the memory cell transistors M11 to M18. The select transistors Q11 and Q12 respectively include gate electrodes 36 and 38 which are hereinafter referred to as "select gate electrodes."
The bit line BL1 may be a metal layer 40 which is formed with a small width to extend and insulatively intersect the control gate electrodes 34, the first select gate electrode 36, and the second select gate electrode 38. In FIG. 3, the bit line BL1 is illustrated to be partly cut away in the lower portion of the drawing for convenience so that a heavily-doped N type (N+type) semiconductor diffusion layer 42 formed in the surface area of the substrate 30 is visible. The layer 42 holds the common source voltage Vs described before. The first select transistor Q11 is electrically connected at the drain to the bit line BL1 via a contact hole portion 44 formed in the metal wiring 40 which is the bit line BL1. The second select transistor Q12 is connected at the source thereof to the common source voltage Vs.
The cross sectional structure of one memory cell M11, for example-of the memory cell transistors included in the NAND cell unit MB1 is shown in FIG. 4 in detail. A thin insulation film 48 is deposited in an element area defined by element isolation insulation layers 50 on the top surface of the P type substrate 30. The insulation layers may be chemical vapor deposition oxide films. The insulation film 48 functions as a gate insulation film. The floating gate electrode 32 is stacked on the gate insulation film 48. The length thereof is determined so that it may partly cover the element isolation insulation layer 50. The floating gate electrode 32 is covered with an insulation layer 52. The control gate electrode 34 having substantially the same width as the floating gate electrode 32 is formed on the insulation layer 52. As shown in FIG. 3, the electrode 32 is arranged to extend to the length corresponding to the word line WL1. The floating gate electrode 32 defines a preselected capacitance between it and the substrate 30; it also defines another capacitance between it and the control gate electrode 34. The control gate electrode 34 is covered with an insulation layer 54. The metal wiring layer 40 which is the bit line BL1 is arranged.
Turning now to FIG. 5, N+type semiconductor diffused layers 58, 60, 62, 64, 66, . . . , 68, 70 and 42 are arranged with a preset distance therebetween along the lengthwise direction of the bit line BL1 on the top surface portion of the P type substrate 30. The N+ type layer 58 serves respectively as the drain of the first select transistor Q11. It will be easily understood by just viewing the drawing that the layer 58 is connected to the metal wiring layer 40 which is the bit line BL1 via the contact hole portion 44. The N+type layer 60 serves as the source of the first select transistor Q11. At the same time, the N+ type layer 60 serves as the drain of the adjacent memory cell transistor M11. Likewise, the N+ type layer 62 serves as the source and drain of the adjacent memory cell transistors M11 and M12. The N+ type layer 42 serves as the source of the second select transistor Q12 and at the same time it is connected to the common source voltage Vs.
Turning back to FIG. 2, the NAND cell units MB1, MB2, . . . , MBn are connected in common to a common source line 80 at the sources of the second select transistors Q12, Q22, . . . , Qn2. The common source line 80 is made of the N+ type semiconductor diffusion layer 42 shown in FIG. 3. The line 80 is kept at the common source voltage Vs, which is set to 0 volts except in an erase operation.
The internal circuit configuration of the sense amplifier circuit 18, the data latch circuit 16, the data comparator 22, and the output buffer 24, which are illustrated in FIG. 1, is shown in detail in FIG. 6. The data latch circuit 16 includes an array of logic gate sections 90 for receiving a latch signal LATCH and an address signal a0, a1, a2, . . . , an. Latch circuits 92 are connected with these logic gates 90, for temporarily latching a data indicative of the address signal that is selected by the logical processing of the logic gates 90. The sense amplifier circuit 18 includes logic gate sections 94 for receiving a sense control signal SENSE and an address signal ai (i=0, 1, 2,. . . , n), and sense amplifiers 96 that are associated with the logic gates 94. When a corresponding one of the logic gates 94 is selected in response to an address signal ai, the sense amplifier circuit 18 senses, at a corresponding sense amplifier 96, the data voltage on the bit line BLi of the selected address and then outputs the same.
The data voltage latched in the data latch circuit 16 is sent to the data comparator 22 via a wiring line 98. The output of the sense amplifier circuit 18 is supplied by a wiring line 100 to the data comparator 22. The data comparator 22 has an inverter 102 connected to the line 100, and an NAND Gate 104 having a first input connected to the output of the inverter 102 and a second input connected to the line 98. The output of the NAND gate 104 is connected to an internal latch circuit 108 through the inverter 106. The internal latch circuit 108 latches a data voltage input thereto in response to latch signals LATCHV and LATCHV. In other words, the comparison result obtained by the data comparator 22 may be maintained temporarily at the internal latch circuit 108. The output of the data comparator 22 will be transferred via the output buffer 24 to the verify-termination detector 28.
FIG. 7 shows a detailed configuration of the gate controller 14 shown in FIG. 1. This controller includes a high-voltage generation circuit 110 for generating a high-level voltage vpp which is supplied to the selected control gate in a data write mode, an intermediate voltage generation circuit 112 which supplies non-selected control gates with an intermediate voltage Vppm, a verify voltage generation circuit 114 for generating a verify voltage Vver in a write-verify operation mode, and an erase/readout control circuit 116. Such circuit configuration is provided for each control gate line.
The high-voltage generator 110 is mainly constituted by a NAND gate G1 for executing a logic processing between a write signal WRITE and an address signal ai, an enhancement type (E-type) N-channel MOS transistor Qel for switching in response to an output signal of the NAND gate G1, E-type P-channel switching MOS transistor Qp1, and an E-type P-channel MOS transistor Qp2 serving as an output buffer. A D-type N-channel MOS transistor Qd2 is provided between the MOS transistors Qe1 and Qp1, for protecting the switching MOS transistor from unintentional application of a high voltage. A D-type N-channel MOS transistor Qd1 is provided between the MOS transistor Qpl and a high-voltage terminal to which the high voltage Vpp is applied, for providing a high-voltage protection for the MOS transistor. Similarly, D-type N-channel MOS transistors Qd3 and Qd4 are provided for the bufferstage MOS transistor Qp2. Using such D-type N-channel MOS transistors may facilitate the high voltage Vpp to be effectively supplied to a control gate line(s) without any decrease in the threshold voltage. In particular, the MOS transistor Qd4 functions, when a control gate line is applied with a positive voltage from an external circuit, to prevent the drain junction of the P-channel MOS transistor Qp2 from being in reverse-biased.
The intermediate voltage generator 112 is arranged similarly as in the above circuit 110: It includes a NAND gate G2, an E-type N-channel switching MOS transistor Qe2 controlled by an output of the NAND gate G2, an E-type P-channel switching MOS transistor Qp3, an E-type P-channel MOS transistor Qp4 serving as an output buffer, and D-type N-channel MOS transistors Qd5 to Qd8.
The erase/readout controller 116 is constituted by NAND gates G3 and G5 for performing logical operation for a read signal READ, an address signal ai, and an address signal ai, an inverter gate I2 for receiving an erase signal ERASE, a NAND gate G6 for logically processing outputs of the inverter gate I2 and the NAND gate G5, an E-type P-channel MOS transistor Qe3 having its gate electrode connected to the output of NAND gate G6, an E-type P-channel MOS transistor Qp5 having its gate electrode connected to the output of the gate G3, and D-type N-channel MOS transistors Qd9 and Qd10 as protection transistors which are provided as shown in FIG. 7.
The verify controller 114 includes a NAND gate G4 for executing a logical processing between a verify signal VERIFY and an address ai, an inverter I1 connected to the NAND gate G4, an E-type N-channel MOS transistor Qe4 having its gate electrode connected to the output of the inverter I1 for supplying a verify voltage Vver to a corresponding control gate line, i.e., word line WLj, and a D-type N-channel MOS transistor Qd11 provided between the transistor Qe4 and the word line WLj.
The verify controller 114 includes a verify voltage generation circuit that may be typically arranged as shown in FIG. 8. The verify voltage Vver is a voltage which is to be generated when a verify signal VERIFY is supplied and which has an intermediate voltage potential between the power supply voltage vcc and the ground potential. The verify voltage Vver is supplied to a certain control gate line (word line) that is selected by the verify voltage generation circuit 114. In this embodiment, the circuit for generating such verify voltage Vver is formed of a series circuit of E-type N-channel MOS transistor Qe6 and Qe7 provided between a power supply voltage terminal Vcc and a ground potential. A voltage divider circuit having resistors R1 to R3 is provided to supply gate electrodes of these transistors Qe6 and Qe7 with a suitable bias voltage.
Principally, the power supply voltage Vcc may be simply applied at a node A of the voltage divider circuit. With such a simple voltage application, a feed-through current will occur undesirably. To prevent such phenomenon, with this embodiment, a switch circuit is provided which consists of E-type N-channel MOS transistors Qe8 and Qe9, E-type P-channel MOS transistors Qp6 and Qp7, and an inverter I3. More specifically, when the verify signal VERIFY is set in the "H" level, the MOS transistors Qe8 is rendered conductive, the transistor Qp7 is rendered conductive, and the transistor Qe9 is rendered nonconductive. As a result, a specific voltage is obtained which is determined in accordance with the voltage division ratio of the voltage divider circuit and has an intermediate voltage level corresponding to the conductive condition of the transistors Qe6 and Qe7. When the verify signal VERIFY is set in the "L" level, the transistor Qe9 becomes conductive, so that the node A of the voltage divider circuit is identical with the ground potential. The verify voltage terminal Vver is thus electrically floating. At this time, no currents flow in the switch circuit, since the transistor Qp7 is rendered nonconductive.
The verify termination detector 28 may be arranged as shown in FIG. 9 to include a flip-flop section 120, an NAND gate 122, and an inverter 124. A verify termination signal Sv appears at the output of the inverter 124.
The operation mode of the EEPROM thus arranged will now be described below.
Prior to execution of data write, i.e., data programming, all the memory cells are first subjected to data-erasing, which is called the "simultaneous data erase." In the data erase mode, all the control gate lines including the select gate lines SG and word lines WL are applied with a voltage of 0 volts. More specifically, in the control circuit configuration shown in FIG. 7, an erase signal ERASE is supplied to the erase/readout controller 116. Responding to the signal, the MOS transistor Qe3 is rendered conductive so that the word lines WL are set at 0 volts. The select gate lines SG1 and SG2 are also kept at 0 volts. While the bit lines BL and the common source line 80 is forced to be electrically floating, the high voltage Vpp is applied to the lightly-doped P type substrate 30 (or an P type well region formed in an N type substrate, if any). Such biasing state is being held for a preselected length of time period, 10 milliseconds, for example, whereby electrons are released from the floating gates of all the memory cell transistors, so that the threshold voltages thereof are shifted to have a negative polarity value. This may corresponds to the data "0" storage condition.
A data write or programming is carried out as will be described as follows. A data of "one word" is latched in the data latch circuit 16. The bit line voltage is controlled in response to the data storage, so that a logical "0" or "1" will be written into a selected memory cell transistor. At this time, a selected word line WLj is applied with the high voltage Vpp; non-selected word lines associated those of non-selected memory cell transistors that are positioned between the selected word line and the first select transistor Qi1--that is, the memory cell transistors Mi1, Mi2, . . . , Mi(j-1)--are applied with the intermediate voltage Vppm. A write signal WRITE is input to the control circuit shown in FIG. 7. In other words, one of the high-voltage generator 110 and the intermediate voltage generator 112 is selectively rendered operative in response to the logical processing between the write signal WRITE and the address signals ai and ai in such a manner that the high voltage Vpp is sent to the selected word line while the intermediate voltage Vppm is applied to the aforementioned non-selected word lines. A bit line associated with the selected memory cell transistor is applied with a 0-volt voltage when a data "1" is to be written; it is applied with the intermediate voltage Vppm in the case of writing a data "0."The time length for maintaining the above biasing condition for data writing is so set as to be much shorter than that used in the conventional data write mode. The maintenance time is preferably 1/100 smaller than the conventional one; it may be 10 microseconds, for example. In the memory cell transistor into which the "1" data has been written, the threshold voltage is shifted to have a positive value. On the other hand, in the memory cell transistor into which the "0" data has been written, the threshold voltage remains at a negative value.
Thereafter, a write-verify operation is in effect. With the present embodiment, verification is made to confirm whether the threshold voltage of data "1"-written memory cells reaches a preselected value. The threshold value may be determined in advance by taking into consideration the data storage characteristic of the memory cell transistors; it is typically 0.5 volts. The above verifying operation is executed with respect to each of the data-written memory cell transistors arrayed along a designated word line WLi.
The timing chart of the verifying operation is shown in FIG. 10. When the sense signal SENSE is at the "H" level, the sense amplifier circuit 18 becomes enable. A column address ai is supplied by the address generator 20. Data is then output on a corresponding data output line, and data in the data latch circuit 16 appears on a latch output line 98 of the data latch circuit 16. In the verifying operation cycle, the controls-gate controller 14 is simultaneously supplied with the verify signal VERIFY and the readout signal READ. As a result of a logical processing between these signals and the address signals ai and ai, the selected control gate line, i.e., word line, is supplied with the verify voltage Vver (=0.5 volts), which has an intermediate voltage level between the power supply voltage Vcc and the ground potential, as described above. The remaining, non-selected word lines are supplied with the power supply voltage Vcc, since the output of the NAND gate G3 in the erase/readout controller 116 is set at the "L" level. At this time, the select gate lines SG1 and SG2 are set at the power supply voltage Vcc, and the bit line is also at the voltage Vcc whereas the common source line 80 is at 0 volts.
With such a voltage application, if a selected memory cell is written with the data "1," and when the threshold voltage of it is more than 0.5 volts, the selected memory cell transistor becomes nonconductive, so that data "1" is read out. If the threshold voltage of the data "1"-written memory cell does not reach 0.5 volts, the selected memory cell transistor is rendered conductive, with the result in that a stored data is read out as a data "0." The written data and the readout data that is obtained during the above verifying operation are then compared by the data comparator 22 with each other. The comparison result is lathed when the latch signal LATCHV is set at the "H" level. If the readout data is a "1" data, it is inverted by the inverter 102 in the comparator circuit 22, and then sent to the NAND gate 104 together with the write data from the data latch circuit 16. When the write data has the "1" level, the readout data is changed to a "0" data by the inverter 106, and latched in the internal latch circuit 108. In such a case wherein the write-in data is "1" data and yet read out as a "0" data due to insufficient writing, it is latched in the latch circuit 108 as the "1" data. When the write-in data is a "0" data, it is latched as a "0" data in the latch circuit 108 in the comparator circuit 22, regardless of the level of the resultant readout voltage. The aforementioned data latching operations performed in the data comparator 22 may be summarized as shown in Table 1 that follows.
TABLE 1______________________________________Data in Data Latch Circuit 1 1 0 0Output of Sense Amplifier Circuit 1 0 1 0Output of Data Comparator 0 1 0 0______________________________________
If even one of the outputs CDATA of the output buffer 24 exhibits "1," the verify termination detector 28 will not generate the verify termination signal Sv. The flip-flop circuit in the verify termination detector 28 shown in FIG. 9 is initiated in response to the write-verify signal VERIFY, which is set at "0" in the write-verify mode. During the data comparison operation, when a "1" appears at the output of the comparator 22, the output of the flip-flop circuit is set at the "0". The verify termination signal Sv is kept at "0" when the data comparison signal CMPEND is set at "1" after the data comparison is completed with respect to all the bit lines BL1, BL2, . . . , BLn. This shows that verifying is not completed for all the write-in data. As is apparent from TABLE 1, "1" data is latched again with respect only to a specific address or addresses at which data programming is still insufficient. With such "relatching," the data "1" writing is repeatedly executed, which may be called the "data-rewriting" operation. A similar verifying operation is again performed. If any memory cell that is insufficient in data writing remains, the data rewriting and verification will be executed again. A plurality of combinations of re-writing and verification will be repeated until any insufficient write-in memory cells no longer remain in the EEPROM. Under such a condition, no "1"s appear in the output of the data comparator 22, and the flip-flop circuit output is being set at "1." When the data comparison completion signal CMPEND is at "1", the verify termination detector 28 then outputs a "1" data as the verify termination signal Sv. Now, the data writing mode is completed.
The application of several voltage signals at the main components of the EEPROM 10 in different operation modes may be summarized in the following TABLE 2. TABLE 2 has been prepared under assumption that a word line WL2 is selected in the data write and write-verify operations.
TABLE 2______________________________________ Write- Erase "1" Write "0" Write Verify______________________________________Bit Line Floating 0 V 10 V 5 VSG1 0 V 10 V 10 V 5 VWL1 0 V 10 V 10 V 5 VWL2 0 V 20 v 20 V 0.5 VWL3 0 V 10 V 10 V 0.5 VWL4 0 V 10 V 10 V 5 VWL5 0 V 10 V 10 V 5 VWL6 0 V 10 V 10 V 5 VWL7 0 V 10 V 10 V 5 VWL8 0 V 10 V 10 V 5 VSG2 0 V 0 V 0 V 5 VCommon Source Floating 0 V 0 V 0 VSubstrate 20 V 0 V 0 V 0 V______________________________________
The data read operation of the EEPROM 10 is performed in substantially the same manner as in the conventional devices.
With the EEPROM 10 embodying the present invention, the length of data-writing time is shortened, and rewriting will be repeatedly executed for insufficient data-write-in memory cells if any. This can prevent any overwriting condition--i.e., unnecessarily increase in the threshold voltage of the memory cell into which data "1" has been written--from taking place due to variation in the manufacturing parameters in a conventional case wherein the writing of data "1" must be completed at a time. It becomes possible to decrease differences among the threshold voltages of the designated memory cells storing the data "1" to be written thereinto. This causes the NAND cell type EEPROM 10 to be much improved in its operational reliability.
Referring now to FIG. 11, a NAND cell type electrically erasable programmable read-only memory or EEPROM in accordance with to another embodiment of this invention is generally designated by a reference numeral "150." NAND cell type EEPROM 150 has a memory array section 152, which is similar in its memory cell matrix configuration to the memory section 12 of the previous embodiment 10 shown in FIGS. 2 and 3.
The memory array section 152 is connected with a row decoder circuit 154 and a column decoder circuit 156. A control-gate controller 158 is connected to the row decoder 154. The control-gate controller 158 is similar in its internal configuration and its function to the controller 14 shown in FIG. 1 and 7. An address buffer section 160 is connected to the decoders 154 and 156. A couple of bit line control circuits 162 and 164 are associated with the memory section 152 and the column decoder 156 as shown in FIG. 11. A substrate voltage control circuit 166 is provided for controlling the voltage of the chip substrate on which the memory section 152 is arranged. An I/O buffer section 168 is connected with the first bit line controller 162.
The embodiment 150 is featured in that the first and second bit line controllers 162 and 164 are provided for the memory array section 152 in such a manner that they are connected respectively to two ends of each of bit lines BL. The first bit line control circuit 162 executes, in a write-verify mode, a sensing operation and a latching operation for a data to be rewritten with respect to all the bit lines BL1, BL2, . . . , BLn, independently of the column address designation. In the write-verify mode, the second bit line control circuit 164 also executes a sensing operation and a latching operation for a data to be rewritten with respect to all the bit lines BL1, BL2, . . . , BLn, independently of the column addressing. These bit line controllers 162 and 164 operate in a combined manner, as will be described below.
During the verify operation, the data being latched by the first bit line controller 162 is written via a bit line BLi into a selected memory cell transistor Mij in the memory array section. After the data writing was completed, the second bit line controller 164 functions as a sense amplifier for sensing a voltage which appears on the bit line BLi associated with the memory cell transistor Mij. The data voltage sensed by the second bit line controller 164 is utilized as a data rewriting voltage. Thereafter, when the data being latched by the second bit line controller 164 is supplied to the same bit line BLi and then written into the same memory cell transistor Mij, the first bit line controller 162 now serves as a sense amplifier for sensing a voltage corresponding to the actually written data. The alternate latching/sensing operations of the combined bit line controllers 162 and 164 will be repeated until when the write-verifying operation is terminated.
The internal arrangement of the combined bit line controllers 162 and 164 are shown in FIGS. 12A and 12B. The first bit line controller 162 has a CMOS flip-flop circuit that may serve as both a sense amplifier and a data latcher and is constituted by E-type P-channel MOS transistors Qp8 and Qp9 and E-type N-channel MOS transistors Qe15 and Qe16 as shown in FIG. 12B. D-type N-channel MOS transistors Qd12 and Qd13 are provided as capacitors at nodes N1 and N2 respectively. Each of these transistors Qd12 and Qd13 has its source and drain which are connected together. The capacitors are for storing electrical charges representing a data which appears on a bit line during the sensing operation.
E-type N-channel MOS transistors Qe10 and Qe11 are rendered conductive or nonconductive in response to a column select signal CSLJ that is selected by the designated column address, thereby to control transmission of data between the input/output lines and the sense-amplifier/data-latcher. E-type N-channel MOS transistors Qe12, Qe13, Qe14 are provided for resetting the above CMOS flip-flop circuit. The MOS transistors Qe12 and Qe13 having their sources connected to a half voltage of the power supply voltage Vcc (Vcc/2) force the flip-flop nodes to reset at the half voltage Vcc/2.
An E-type N-channel MOS transistor Qe17 acts as a transfer gate which selectively connects the flip-flop nodes to a corresponding bit line. E-type N-channel MOS transistors Qe18 and Qe19 constitutes a circuit for supplying the bit lines with electrical charges in accordance with the data contents of the CMOS flip-flop circuit during the write-verify operation. A D-type N-channel MOS transistor Qd14 and an E-type P-channel MOS transistor Qp10 form a circuit for executing a precharging operation for the bit lines in a data read mode. The MOS transistor Qd14 is provided to prevent the intermediate voltage Vppm (about 10 volts), which is applied to the bit lines in a data write mode, from being applied to the MOS transistor Qp10. An E-type N-channel MOS transistor Qe20 and a D-type N-channel MOS transistor Qd15 function to prevent the high voltage vpp (about 20 volts) to be applied to the bit lines in a data erase mode from being erroneously transferred to the first bit line controller 162. These transistors Qe20 and Qd15 are connected in series with each other, thereby to increase or jack up the withstanding voltage level thereof.
The second bit line controller 164 shown in FIG. 12A is essentially similar in its circuit configuration to the aforementioned first bit line controller 162. E-type MOS transistors Qe30 and Qe31 may correspond to the transistors Qe12 and Qe13 shown in FIG. 12B; an E-type MOS transistor Qe29 correspond to the transistor Qe14; transistors Qp11 and Qp12 to the transistors Qp8 and Qp9; transistors Qe27 and Qe28 to those Qe15 and Qe16; transistors Qd17 and Qd18 to those Qd12 and Qd13; a transistor Qe26 to the transistor Qe17; a transistor Qe24 to the one Qe19; a transistor Qe25 to the one Qe18; a transistor Qe22 to the one Qe20; and, a transistor Qd16 to the transistor Qd15 shown in FIG. 12B, respectively. An E-type N-channel MOS transistor Qe23 shown in FIG. 12A is provided for resetting the bit lines.
The memory array section 152 is provided between the first and second bit line controllers 162 and 164 as shown in FIG. 11. Each of the bit lines BL running between the first and second controllers 162 and 164 is subdivided into a couple of bit line portions BLa and BLb, as shown in FIG. 12A. The length ratio of the subdivided bit line portions BLa and BLb may be set as represented below:
La:Lb=3:2
where, "La" and "Lb" are the lengths of subdivided bit lines BLa and BLb, respectively. The above subdivision ratio determines the actual level of a bit line precharging voltage in the read mode; for example, the precharging voltage is 3 volts when the power supply voltage Vcc is 5 volts.
Now, the operation modes of the EEPROM 150 will be described hereinafter.
A simultaneous data erase is first carried out for all the memory cells of the EEPROM 150 before a data programming mode is executed. To erase data, a 0-volt voltage is applied to all the control gate lines, i.e., word lines WL. More specifically, in the control circuit shown in FIG. 7, an erase signal ERASE is supplied to the erase/readout controller 116. Responding to the signal, the MOS transistor Qe3 becomes conductive so that a corresponding control gate line WLj is applied with a 0-volt voltage. At this time, the first and second select gate lines SG1 and SG2 are also supplied with the 0-volt voltage. All the bit lines BL and the common source line 80 are set in an electrically floating condition. The high voltage Vpp is then applied to the substrate 30 having its surface in which the memory cell transistors M are formed in a manner as shown in FIG. 3. With such application of high voltage Vpp, a control signal ERPH shown in FIGS. 12A and 12B is set at a 0-volt potential level, whereby the high voltage Vpp is prevented from being transferred to the first and second bit line controllers 162 and 164. By maintaining the above state for a suitable length of time period, 10 milliseconds, for instance, electrons are released simultaneously from the floating gate electrodes of all the memory cell transistors. The threshold voltages of the memory cell transistors are shifted so that the "0" storage condition is given.
When the EEPROM 150 is set in the data write (programing). mode, a data of "one-word" is latched in the sense-amplifier/data-latcher provided in the first bit line controller 162. An input data is transferred from the data input/output buffer 168 to the input/output lines. A column select signal CSLj is selected to have the "H" level, and the input data is then latched in the CMOS flip-flop in the first bit line controller 162. As shown in FIGS. 12A and 12B, signals φpd and φwd are kept at the power supply voltage Vcc until when the data latching is completed. Thereafter, the signals φpd, φwd, FFSD, ERPH and φbe are set at the potential level corresponding to the voltage vppm. The bit lines are supplied with a 0-volt voltage when data "1" is to be written; they are supplied with the voltage vppm when data "0" is written.
The high voltage Vpp is applied to a selected word line WLj, while the intermediate voltage Vppm is applied to those of non-selected word lines WL1, WL2, . . . , WL(j-1), which are positioned between the first select gate line SG1 and the selected word line WLj. A write signal WRITE is supplied to the control circuit shown in FIG. 7. Responding to the logical processing between the write signal WRITE and the address signals ai and ai, one of the high voltage generator 110 and the intermediate voltage generator 112 is rendered operative. As a result, the high voltage Vpp is applied to the selected word line WLj, and the intermediate voltage Vppm is the above-identified non-selected word lines WL1, . . . ,Wi(j-1).
The length of time for holding the above biasing condition for the data programming is sufficiently shorter than--preferably 1/100--the normally selected one in the conventional data programming scheme; for example, it is preferably 10 microseconds. Under such a condition, in a memory cell or cells into which data "1" has been written, the threshold voltages thereof are shifted to have a positive value. On the other hand, in the remaining memory cells into which data "0" has been written, the threshold voltages thereof are kept in a negative value.
A write-verify operation is then executed. With this embodiment, verification is made to confirm whether the threshold voltages of the data "1" storing cells increase up to a desirable value. This value may be determined on the basis of the physical data storage characteristic of the memory cell transistors; it is 0.5 volts, for example. The write-verification will be done with respect to each of the memory cells associated with the selected word line WLj.
The write-verify operation will be explained in greater detail with reference to FIGS. 13A and 13B, which show the practical timing chart of the main signals generated during the writing and write-verifying operations. Data is sent from the input/output buffer to the data input/output lines I/O and I/O. In the case of data "1," the I/O line is at the "H" level; In the case of data "0," the I/O line is at the "L" level. When the column select signal CSLj that has been selected in response to address designation is at the "H" level, the data is latched in the MOS flip-flop included in the first bit line controller 162. After latching of one-word data, the reset signal RESET becomes at the "L" level. The bit lines are thus set in the electrically floating condition.
When the signal PVD has the "H" level, the bit lines BL are precharged to a precharge voltage corresponding to the difference between the power supply voltage Vcc and the threshold voltage Vth (Vcc-Vth) in the case of data "0" only. Thereafter, the signal FFSD is set at the "H" level. Those of the bit lines BL that are supplied with data "0" are precharged to the voltage Vcc-Vth; the remaining bit lines that are with data "1" are set at 0 volts The signals φwd φpd FFSD, ERPH and φbe are set at the intermediate voltage Vppm. The data "0" supplied bit lines are maintained at the voltage Vppm-Vth, whereas the remaining, data "1" supplied bit lines are set at 0 volts. Under the condition, voltage application to the word lines WL are made in the same manner as described above. The data "0" and "1" may thus be stored in the memory cell transistors arrayed along the selected word line WLj.
Once the data writing is completed, the signals φwd, φpd, φbe become Vcc, and the signal FFSD becomes at 0 volts. The reset signal RESET is at the "H" level, and the bit lines BL are reset to 0 volts.
A verify operation is now executed. First, the signal φbe is at "L" level, so that the bit lines BLa become electrically floating. The signal PRE is changed at the "H" level; the bit line BLa is thus charged to have a voltage equal to the power supply voltage Vcc. Then, the signals PRE and RESET are set at the "L" level, and the signal φbe is at the "H" level. The bit lines BLa and BLb are electrically floating with a certain voltage 3Vcc/5 (3 volts when Vcc is 5 volts). While the signals PRE and RESET are set at the "L" level, the signals φnu and φpu are at Vcc/2 (=2.5 volts).
When the signal φeu is at the "H" level, the voltage potentials at the nodes N3 and N4 of the CMOS flip-flop included in the second bit line controller 164 becomes equal to Vcc/2 (=2.5 volts). Then, the signal φeu is at the "L" level, whereas the signal FFSU is at the "H" level. With such a voltage application, the word lines approach the desired voltage in the same manner as mentioned above. The selected word line WLj is set at the verify voltage Vver; if the actual threshold voltage is less than that value, the voltage on bit line will decrease. This may be summarized as follows: If the threshold voltage of the memory cell(s) in which the data "1" has been written is lower than the verify voltage Vver and the data write condition is not sufficient, the bit line voltage will decrease below the voltage Vcc/2 (=2.5 volts). This requires that data "1" be rewritten in the same memory cell(s). If it is after the data "0" is written, the bit line voltage will obviously decrease. To eliminate unintentional confusion between these voltage decrease phenomenons, the signal PVD is forced to be at the "H" level once after the word line is set at 0 volts. This enables a recharging to be executed only when the data "0" has been latched in the first bit line controller 162. In other words, it is specifically arranged that, only when the threshold voltage of the memory cell(s) is lower than the verify voltage Vver after the data "1" has been written thereinto, the bit line(s) are forced to decrease below the voltage Vcc/2.
At this time, it can be identified in advance whether the voltage at the node N3 is higher than the voltage Vcc/2; the voltage at the node N4 is the voltage Vcc/2. The signal PVD is set at the "L" level, and the signal FFSU is at the "L" level. The nodes N3 and N4 are thus set in an electrically floating condition. Under the condition, by causing the signal ¢nu to be at 0 volts and simultaneously the signal φpu to be at the voltage Vcc, the difference between the voltage potentials at the nodes N3 and N4 may be sensed. The sensed voltage difference is then latched. This latched voltage will be used as a rewrite data voltage.
As has been described hereinbefore, the first and second bit line controllers 162 and 164 are essentially identical in their circuit configurations with each other; one of the two is basically same in its operation as the other. In this embodiment, a rewriting is first executed in the second bit line controller 164; a write-verification is then performed with the first controller 162. The combination of such rewriting and verifying operations will be repeated, for 128 times, for example, until the all the designated memory cell transistors meet the desirable data write condition.
FIG. 14 shows a timing chart for a data readout operation of the EEPROM 150. When an address enters, the signal φbe is first changed at the "L" level. The bit line BLa positioned on the side of the first bit line controller 162 becomes electrically floating. Subsequently, the signal PRE is at the "H" level, so that the bit line BLa is precharged to the voltage Vcc. The signals PRE and RESET are set at the "L" level; the signals φpd and end are at Vcc/2. When the signal φbe is changed to have the "H" level, the bit lines BLa and BLb are precharged up to 3 Vcc/5 (=3 volts). Then, the signal φed is set at the "H" level, and the nodes N1 and N2 on the side of the first bit line controller 162 are equal to Vcc/2. Thereafter, the signal φed is at the "L" level. The signal FFSD changed to have the "H" level; simultaneously, the word lines WL are set in suitable voltage levels as has been already described above. If the storage data is "0," the voltage on a corresponding bit line decreases; if the data is "1," the bit line voltage is kept unchanged. This bit line voltage is then transferred to the node N1. When the signal FFSD is at the "L" level, the signal φpd equals Vcc, and the signal φnd is 0 volts, a readout data is sensed by the CMOS flip-flop circuit in the first bit line controller 162. When the signal RESET is at the "H" level, the bit line is reset. The column select signal CSLJ selected in response to address designation is now changed to have the "H" level. The readout data is sent onto the data input/output lines I/O and I/O, and then output from the input/output buffer 168 (see FIG. 11).
The following TABLE 3 summaries the aforementioned application of several voltages at the main components of the EEPROM 150 in several operation modes of the same. In Table 3, it is assumed that a word line WL2 is selected during the data writing and write-verifying operations.
TABLE 3______________________________________ Write- Erase "1" Write "0" Write Verify Read______________________________________Bit Floating 0 V 10 V 3 V 3 VLineSG1 0 V 10 V 10 V 5 V 5 VWL1 0 V 10 V 10 V 5 V 5 VWL2 0 V 20 V 20 V 0.5 V 0 VWL3 0 V 10 V 10 V 5 V 5 VWL4 0 V 10 V 10 V 5 V 5 VWL5 0 V 10 V 10 V 5 V 5 VWL6 0 V 10 V 10 V 5 V 5 VWL7 0 V 10 V 10 V 5 V 5 VWL8 0 V 10 V 10 V 5 V 5 VSG2 0 V 0 V 0 V 5 V 5 VCommon Floating 0 V 0 V 0 V 0 VSourceSub- 20 V 0 V 0 V 0 V 0 Vstrate______________________________________
The present invention is not limited to the above-described specific embodiments and may be practiced or embodied in still other ways without departing from the spirit or essential character thereof. For example, in the above embodiments, a 0.5-volt voltage is used as the verification standard voltage (Vver); such value may be modified to have another value in the practical application for using the write-verifying concept of the present invention. The same thing goes with the writing time length of one cycle: The time length may be further shortened so as to increase the total number of time of executing the combined data-writing and write-verifying operations with fine repeating intervals, whereby compensation for variation in threshold voltages among the designated memory cell transistors can be made at higher precision. In addition, the write-verify concept of the present invention may also to applied, other than the NAND cell type EEPROMs utilizing the tunneling effect for carrier movement between the substrate and the floating gate electrodes as in the above embodiments, to those which utilize the hot-electron injection or the like. | A non-volatile semiconductor memory device including a plurality of bit lines; a plurality of word lines insulatively intersecting the bit lines; a memory cell array including a plurality of memory cells coupled to the bit lines and the word lines, each memory cell including a transistor with a charge storage portion; a plurality of programming circuits coupled to the memory cell array (i) for storing data which define whether or not write voltages are to be applied to respective of the memory cells, (ii) for selectively applying the write voltages to a part of the memory cells, which part is selected according to the data stored in the plurality of programing circuits, (iii) for determining actual written states of the memory cells, and (iv) for selectively modifying the stored data based on a predetermined logical relationship between the determined actual written states of the memory cells and the data stored in the plurality of programming circuits, thereby applying the write voltages only to memory cells which are not sufficiently written to achieve a predetermined written state. | 6 |
TECHNICAL FIELD
This invention relates to a method to deposit thin films. Specifically, a method to sputter deposit multilayer thin films on a substrate by bombarding a target with ions produced by a radio-frequency excited ion beam gun is disclosed.
BACKGROUND OF THE INVENTION
Many schemes and apparatus have been devised to produce multilayer thin films. These films are used in semiconductor fabrication, optical waveguides, and highly reflective mirrors such as those used in ring laser gyroscopes. Sputter deposition usually takes place in a vacuum chamber where a target material is impacted by ion beams to sputter material off the target by collision mechanics. This sputtered material would then be deposited on a substrate to produce the device.
Several problems have been associated with prior art systems. It has been difficult to generate a beam of ions which is free of contaminants and of a high enough energy to be effective. It has also been difficult to impart enough energy to the sputtered material to ensure a uniform deposited film of a known thickness, density and surface smoothness. The major problems, therefore, have been with the source of the ions to perform the sputtering. Ionizing sources and methods have, therefore, been the subject of significant work.
The simplest of these ionizing methods was to use a filament, or thermionic emitter, to generate electrons within the ionization chamber. The electrons created by the filament collided with the gas molecules, knocking off electrons from the gas molecules to cause the molecules to become positively charged. This method, although operable, had several disadvantages. The filaments tended to have a short life. Because the filaments were thermionic emitters and were at a negative electrical potential relative to the ionized gas, material was sputtered or evaporated off of the filament which caused contamination to be introduced into the ion beam.
An improvement upon the filament type of ion generation was the introduction of a hollow cathode. This eliminated the need of a filament and greatly increased the operational life. Potentials for contamination of the ion beam due to materials present in the hollow cathode were still present.
Further advances of ion beam generating devices included using a high-frequency generator coupled to either plates or coils within the chamber to ionize the gas molecules through excitation by the high-frequency energy. These materials, especially coils within the plasma field, also created contamination in the ion beam. An advancement, placing a coil outside the gas chamber helped to eliminate this contamination. However, external magnetic fields were usually required to contain the plasma within the chamber, enhancing ionization efficiency and to prevent arcing from the plasma to various components within the chamber. The arcing could cause a rapid degradation of the plasma and ultimate destruction of the components within the chamber. Most of the attempts to use high-frequency plasma generation also required that the generator coil be cooled by internal water means. This introduced the problem of having each end of the coil at the same potential, preferably ground potential, to prevent the high-frequency energy from being bled off to ground. Elaborate matching networks, or tight control of the length of the waveguide or coil, were required in order to accomplish these goals.
A need, therefore, exists for being able to generate a beam of positively charged gas molecules without contaminating the beam by the plasma touching contaminating fixturing within the chamber and without the need of water cooled coils or external magnetic fields.
A need also exists to translate substrates within the deposition chamber to insure uniform deposition.
A further need exists to be able to translate targets within the deposition chamber to produce multilayer films.
SUMMARY OF THE INVENTION
The present invention deposits thin films in either a single layer or multiple layers on a substrate. A supply of inert gas is fed to a radio-frequency excited ion beam gun where the gas is ionized into positively charged gas ions into a plasma. The gas ions are extracted from the ion beam gun in a stream or column of ions. The stream of ions is shaped by shutters and directed against targets within a vacuum chamber. The target material is held in a translatable target holder positioned at an angle to the beam. Multiple targets may be held by the holder and selectively translated into and out of the stream of ions.
A plurality of substrates are held above the target so that target molecules sputtered off the target by collision mechanics may be deposited on the substrates. The substrates are mounted in a planetary holder which rotates the substrates into and out of the stream of sputtered target molecules to allow uniform deposition.
It is an object of the invention to uniformly deposit thin films on a substrate.
It is a further object of the invention to provide inexpensive and repeatable thin film deposition using ions created in a radio-frequency excited ion beam gun.
It is another object of the invention to deposit multilayer films of different material on a plurality of substrates.
These and other objects of the invention will be apparent from the following detailed description of a preferred embodiment when read in connection with the appended drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side view of a sputter deposition apparatus as described in the present invention.
FIG. 2 is a top view of a sputter deposition apparatus as described in the present invention.
FIG. 3 is a longitudinal cross-section of the ion producing chamber of the ion beam gun of the present invention.
FIG. 4 is a partially cut away longitudinal view of the ion beam gun of the present invention.
FIG. 5 is a perspective blow-up view of the components of the ion producing chamber of the ion beam gun of the present invention.
FIG. 6 is an electrical block diagram showing the electrical components and their interconnection to the components of the ion producing chamber of the ion beam gun of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to FIG. 1, a vacuum chamber 20 is provided which can be evacuated to a very low pressure by vacuum pump 22. In a preferred embodiment, the vacuum chamber 20 operates at a pressure of 1×10 -4 Torr Mounted to the wall of the vacuum chamber 20 is an ion gun 30, whose details and operation will be explained below. The ion gun 30 is supplied with a source of inert gas 38 which, in the preferred embodiment, is xenon. Other inert gases, such as argon, have also been used with equal results. The ion beam gun 30 produces a stream of positively charged ions 42 by means of radio-frequency excitation, as will be explained below. This ion beam 42 is extracted from ion gun 30 and progresses through a plurality of shutters 32 and 34. These shutters 32 and 34 are, in the preferred embodiment, circular titanium plates having apertures of various diameters through which the ion beam 42 is directed and shaped into a coherent beam of positively charged inert gas ions.
A translatable target holder 40 is provided to hold a target 50 at an acute angle to the ion beam 42. The ion beam impinges the target 50 and knocks material off the target in the direction of the solid arrows of FIG. 1. The material sputtered off the target is directed toward a plurality of substrates 50 and 52 which are held by a substrate holder 60. Substrate holder 60 has an axis 61 about which the substrate holder 60 can rotate. There are a plurality of substrate holders, such as shown as substrate holders 60 and 62 in FIG. 1. Each of the substrate holders has a centrally located central axis, such as axis 63 for substrate holder 62. All of the substrate holders are held by a common carrier 70. The common carrier 70 has a central axle 71 about which the carrier can rotate. This arrangement allows the individual substrates 52, 54, etc. to follow an elliptical retrograde motion within the vacuum chamber 20. As can be seen if FIG. 1, as the carrier 70 rotates and the individual substrate holder 60 rotate on their axis, the substrates 52 and 54 are rotated into and out of the stream of sputtered material shown by the solid arrows in FIG. 1.
Because the beam of ions 42 are positively charged, a neutralizer 90 is provided to provide electrons to combine with the positive molecules to form a stream of material with a net zero electrical charge. This prevents positive ions from building up inside the vacuum chamber 20 and extinguishing the ion beam 42. Because, as will be explained below, the majority of the materials used in the sputter deposition of thin films for this invention are oxides, a source of oxygen 80 is provided to maintain a proper stoichiometric ratio for efficient deposition.
Referring now to FIG. 2, it can be seen that the target No. 2 50 can be of one material and another target, target No. 1 51, can be of another material. FIG. 2 also shows how the target holder 40 can translate the targets into and out of the ion beam 42. In this manner, a multitude of different materials can be sputtered deposited on the substrates one layer upon an additional layer without stopping the deposition process. In a preferred embodiment shown in FIG. 2, target material No. 1 51 can be silicon dioxide. In an alternate embodiment, target material No. 1 51 may be silicon dioxide doped with additional materials such as titanium dioxide or zirconium dioxide. Similarly, target No. 2 50, in a preferred embodiment, may be titanium dioxide. In an alternate embodiment, target No. 2 50 may be zirconium dioxide. In a further embodiment, target No. 2 50 may be titanium dioxide doped with between 5% to 20% silicon dioxide. While in a further embodiment, target No. 2 50 may be zirconium dioxide doped with between 5% to 20% silicon dioxide. In this manner, multiple layer optical films may be deposited having alternating layers of silicon dioxide, titanium dioxide, zirconium dioxide or various combinations of silicon dioxide-titanium dioxide mixture or silicon dioxide-zirconium dioxide mixture.
Referring now to FIG. 3, the ion beam gun has a chamber, or vessel, 100 for containing a gas to be ionized. The vessel 100 has side walls 200 which, in the preferred embodiment, is a high temperature cylindrical glass tube. Side wall 200 can, of course, be of any geometric shape such as square, wherein there would be side walls, or other geometric shapes. In an alternate embodiment, the side walls 200 can be made of fused quartz. It has been found, however, that utilizing a high temperature glass for side walls 200 will cut down on the ultraviolet radiation which emanates through the transparent side walls. The only requirement is that the material be high temperature dielectric material so that it does not melt or conduct radio-frequency energy and also be of sufficient integrity that there be minimal sputtering or loss of materials from the inside of the side walls caused by the ionized gas.
The vessel, or chamber, 100 also has a first closed end 202 made of a suitable material such as aluminum and a second end 204 having an aperture therethrough, again made of a suitable material such as aluminum. The aluminum makes an ideal material because it is conductive and it is not affected by the plasma because the plasma is shielded from the aluminum first end 202 and the second end 204 by other components within the vessel 100, as will be explained below.
A seal 206 is provided to mate between the side wall 200 and the first end 202 to form a gas-tight seal. A similar gasket 208 is designed to fit between the side wall 200 and the second end 204, again, to form a gas-tight seal. Suitable through bolts 210 connect the first side wall 202 to the second side wall 204. Because, as will be explained below, the first end 202 and the second end 204 are at different electrical potentials, it is necessary to electrically isolate through bolts 210 from first end 202. A suitable insulator 220 is provided in the first end 202 to prevent the through bolt 210 from being impressed with the electrical signals which will ultimately be placed on the first end 202. A suitable nut 222 completes the assembly to contain the side wall 200 between the first end 202 and the second end 204. A coil 230, in a preferred embodiment constructed of copper tubing, is wound about the outside of the side wall 200, but spaced apart from the side wall 200 by suitable insulators 232. A gas inlet 240 is provided in the first end 202 to allow gas to be injected into the chamber 100.
A first anode plate 242 and a second anode plate 244 are electrically and mechanically connected to a center post 246 which, in turn, is electrically and mechanically connected to the first end 202.
Adjacent to the second end 204 inside the chamber 100 is a resonator 250. Resonator 250 is, in the preferred embodiment, a flat circular titanium plate having an aperture therethrough and outstanding flange about the inside perimeter of the aperture in second end 204. The resonator 250 is electrically insulated and mechanically separated from the second end 204 by a glass insulating plate 252. The resonator 250 is mechanically attached to an insulator 254 by means of titanium screws 256. Within the aperture of the second end 204 is a multi-apertured screen grid 260 and a multi-apertured accelerator grid 262 which are spaced apart and held by insulating spacers 270 which attach to the insulator 254.
Referring now to FIG. 4, an additional through bolt 212, an additional insulating spacer 224 and attachment nut 226 are shown in more detail. Similarly, an additional standoff insulator 234, similar to 232, is shown holding the coil 230.
The coil 230 is a length of conductive material wound into a solenoid of between three and four turns about the outside of side walls 200. The coil 230, in a preferred embodiment, is approximately three and one-half turns about the side walls 200 of 3/8 inch diameter thin wall copper tubing. The coil 230 has a first end 280 which, in the preferred embodiment, is attached to the second end of the chamber 204 and a second end 284 which has an electrical connection which will be explained below. In addition, an intermediate point has an electrical connector 282 attached. The intermediate point is approximately one-third of a turn from the first end 280 of the coil 230.
The complete gun assembly has a fan mounting flange 290 which is spaced apart from the first end 202. The flange has an aperture with a fan 292 located therein. Fan 292 forces cooling air through the ion beam gun between the outside of the side wall 200 and a metal protective shield 298. The air exits from exit holes 300 located about the periphery of the shield 298 in the area of the second end 204.
As can be seen in FIG. 4, a source of gas 38 is transmitted by means of tubing 296 to the gas inlet port 240 to be introduced into the chamber 100.
Referring now to FIG. 5, a more detailed description of the various components can be seen. In the preferred embodiment, the anode consists of two plates, a first anode plate 242 and a second anode plate 244 spaced apart and mounted on a common central post 246. The post 246 is mechanically and electrically connected to the first end plate 202 of the vessel.
The first anode plate 242 and the second anode plate 244 each have a plurality of slits 245 radiating outwardly from the center post 246 toward the perimeter of each plate. In the preferred embodiment, there are eight slits in both the first anode plate 242 and the second anode plate 244. The second anode plate 244 is rotated, or orientated, on the center post 246 in such a way that the slits 245 in the first anode plate 242 do not overlap the slits 245 in the second anode plate 244. The slits prevent any eddy currents from being induced in either the first anode plate 242 or the second anode plate 244 by the radio-frequency energy impressed on the coil 230. The slits 245 also provide a gas path to uniformly disperse and diffuse the gas within the vessel.
Second anode plate 244 is spaced apart from the side wall 200 of the vessel 100 and from the first end plate 202 so that no plasma will be generated between the second anode plate 244 and the first end plate 202. Similarly, the first anode plate 242 is spaced apart from the side wall 200 and the second anode plate 244 in such a manner as to prevent a plasma from being generated between the first anode plate 242 and the second anode plate 244.
Experimentation has shown that arcing could occur from the plasma to the coil 230 through the insulating side wall 200 if the coil 230 is placed directly on the insulating side wall 200. Another problem with placing the coil 230 directly against the insulating side wall 200 is that material from the inside surface of the side wall 200 could sputter off the inside of the side wall 200, decreasing the side wall 200 strength and contaminating the ion beam with the sputtered material. Placing the coil 230 directly against side walls 200 can also cause hot spots on side walls 200 which can lead to additional problems.
Spacing the coil 230 apart from the side wall 200 to provide an air gap between the coil 230 and the side wall 200 minimizes these problems. The coil 230, in the preferred embodiment, is spaced apart from the side wall 200 by means of a plurality of insulating spacers, such as spacer 232 and spacer 234. This not only prevents arcing, contamination and sputtering of the side wall 200, but also provides an air path between the coil 230 and the side wall 200 to allow cooling air from the fan 292 to further cool the coil 230 and the surface of the side wall 200.
Again, referring to FIG. 5, more specific detail of screen grid 260 and accelerator grid 262 can be seen. The screen grid 260 has a plurality of apertures. These apertures in the screen grid 260 are holes approximately 0.075 inches in diameter and having a density of approximately 100 holes per square inch. The accelerator grid 262, similarly, has a plurality of apertures. The apertures in the accelerator grid 262 are approximately 0.050 inches in diameter and have a density of approximately 100 holes per square inch. Both the screen grid 260 and the accelerator grid 262 are, in the preferred embodiment, constructed out of a graphite material. The apertures in the screen grid 260 and the apertures in the accelerator grid 262 are aligned one to the other.
Referring now to FIG. 6, the electrical interconnection of the various components to the ion beam gun can be seen in detail. A direct current power supply 302, which is adjustable between approximately 1,000 volts and 2,000 volts, is provided to supply electrical potential through filter 304 to the first end 202 of the ion beam gun through an electrical connection to the center post 246. Power supply 302 also supplies its voltage through a filter 306 to the resonator 250. Similarly, the same voltage is applied through filter 308 to the screen 260. This positive DC potential, which in the preferred embodiment, has been found to be effective at 1,750 volts, is used to partially contain the plasma and prevent the plasma from contacting either the first anode plate 242, the resonator 250 or the screen 260. The power supply 302 is a second power supply.
The first power supply is the radio-frequency generator 320. The radio-frequency generator 320 can supply energy having a frequency which is variable between 6 megahertz to 50 megahertz and power between a few watts to several hundred watts. The radio-frequency generator 320, in the preferred embodiment, outputs a standard industrial frequency of 13.56 megahertz. The radio-frequency energy is sent through a matching circuit 322 and connected to the intermediate point 282 of the coil 230. The first end of the coil 230 is connected to the second end plate 204 which is grounded and, therefore, the first end of the coil 230 is at ground potential. The second end 284 of the coil 230 is connected to a first end of a variable capacitor 324, which is variable between the range of 5 microfarads to 100 microfarads. A second end of variable capacitor 324 is connected to ground.
A plurality of capacitors 330, 332 and 334, typically 0.01 picofarads capacitors, have their first end connected to the first end 202 of the vessel 100. A second end of capacitors 330, 332, and 334 is connected to ground. In the preferred embodiment, as shown in FIG. 4, this connection is made through the through bolts, such as through bolt 210. Capacitors 330, 332 and 334 drain off any induced radio-frequency charge induced in the first end 202 by the radio-frequency energy supplied to coil 230. It should be noted that the RF energy supplied to coil 230 does induce eddy currents in resonator 250. It has been found that the inducing of the eddy currents in resonator 250 increases the beam strength of the output beam of the ion beam gun by approximately 20% when used in conjunction with the capacitors 330, 332 and 334. A third power supply 340 supplies a negative DC potential through filter 342 to the accelerator grid 262. This extracts the ions from inside chamber 100 to be used for the purposes intended.
It has been found that by using an input wattage from the RF generator of approximately 550 watts that an output beam of 1,750 volts at 200 milliamperes of current can be achieved.
OPERATION
In operation, sample holders 60 and 62 are removed from vacuum chamber 20 and loaded with a plurality of substrates 52, 54 etc. The substrate holders 60 and 62 are then inserted onto carrier 70 along with a plurality of other holders holding a plurality of substrates.
A plurality of targets 50 and 51 are placed on target holder 40 within the vacuum chamber 20. The vacuum chamber 20 is then closed and sealed and evacuated by vacuum pump 22. The ion beam gun 30 is then supplied with an inert gas 38 and activated, as will be explained below.
A supply of inert gas, such as xenon or argon, is supplied through source 38 into the inside of chamber 100 at a flow of 3.5 standard cubic centimeters per minute. The gas is diffused through slots 245 in second anode plate 244, and slots 245 in the first anode plate 242 and about the perimeter of anode plates 242 and 244 to uniformly disperse within the chamber 100.
The coil 230 is supplied with radio-frequency energy from the first power supply, radio-frequency generator 320 through matching circuit 322. The frequency of the radio-frequency generator is, in the preferred embodiment, 13.56 megahertz with an output power of 550 watts. The matching circuit 322 matches the output impedance of the radio-frequency generator 320 to a transmission line impedance of 50 ohms. The transmission line from the matching circuit 322 is connected to the intermediate point 282 on coil 230 so that the impedance from the intermediate point 282 to ground is near 50 ohms when the plasma is generated and operating.
The first end 202 of vessel 100 and, subsequently, the anode plates 242 and 244 are supplied with 1,750 volts DC from the second power supply 302. The second power supply 302 also supplies 1750 volts DC to the resonator 250 and screen grid 260.
The ions thus generated are extracted from the vessel 100 by applying a second direct current voltage, which in the preferred embodiment is a negative 100 volts, from the third power supply 340 onto accelerator grid 342. In the preferred embodiment described above, the output of the ion beam has been determined to be 200 milliamperes at 1,750 volts.
Having illustrated and described the principles of the invention in a preferred embodiment, it should be apparent to those skilled in the art that the invention can be modified in arrangement and detail without departing from such principles. I claim all modifications coming within the spirit and scope of the following claims. | The present invention discloses a method to deposit thin films on a substrate. An inert gas is introduced into a radio-frequency excited ion beam gun. The ions thus produced are directed to a target where molecules of the target are sputtered off and deposited on a substrate. A method of translating different targets into the ion beam is provided in order to produce multilayer films with different properties in each layer. A method is also provided to rotate the substrates into and out of the path of the sputtered molecules to insure a uniform film. | 2 |
BACKGROUND OF THE INVENTION
Emulsion polymerization is used commercially to synthesize a wide variety of polymers. It is frequently desirable to reduce the molecular weight of such polymers. This is typically accomplished by conducting the emulsion polymerization in the presence of a chain transfer agent.
Mercaptans are normally used as chain transfer agents in emulsion polymerizations. The mercaptans used in commercial applications are typically complex mixtures of hundreds of similar compounds having boiling points within a narrow range. The chain transfer activity of different mercaptans with such mixtures can vary substantially. To further complicate the situation, the distribution of various mercaptans can also vary substantially between lots of material obtained from commercial sources. Thus, consistent molecular weight control is typically difficult to attain in free radical emulsion polymerizations. The use of mercaptans as chain transfer agents also results in odors that workers and customers often find very undesirable.
One of the most important products made by emulsion polymerization is styrene-butadiene rubber. A wide variety of rubber products are made with styrene-butadiene rubber (SBR). For instance, large quantities of SBR are utilized in manufacturing tires for automobiles, trucks, aircraft and other types of vehicles. SBR is commonly used in manufacturing tires because it generally improves traction characteristics.
SBR can be synthesized by utilizing either solution or emulsion polymerization techniques. SBR made by emulsion polymerization (emulsion SBR) generally exhibits better traction characteristics in tire tread compounds. However, SBR made by solution polymerization (solution SBR) typically exhibits much better rolling resistance and treadwear characteristics in tire treads.
In the synthesis of SBR by solution polymerization techniques, an organic solvent is used which is capable of dissolving the monomers (1,3-butadiene and styrene), SBR and the polymerization catalyst or initiator. As the polymerization proceeds, a solution of the SBR in the solvent is produced. This polymer solution is sometimes referred to as a “polymer cement.” The SBR is subsequently recovered from the polymer cement and can then be employed as a dry rubber in desired applications; such as, in formulating tire tread rubbers.
Typical emulsion systems employed in the synthesis of SBR contain water, an emulsifier (soap), a free radical generator, styrene monomer, 1,3-butadiene monomer, and optionally a chain transfer agent, such as a mercaptan. For example, in free radical emulsion polymerization systems, radicals can be generated by the decomposition of peroxides or peroxydisulfides.
Commonly employed initiators include t-butyl hydroperoxide, pinane hydroperoxide, para-menthane hydroperoxide, potassium peroxydisulfate (K 2 S 2 O 8 ), benzoyl peroxide, cumene hydroperoxide and azobisisobutyronitrile (AIBN). These compounds are thermally unstable and decompose at a moderate rate to release free radicals. The combination of potassium peroxydisulfate with a mercaptan such as t-dodecyl mercaptan is commonly used to polymerize butadiene and SBR. In hot recipes, the mercaptan has the dual function of furnishing free radicals through reaction with the peroxydisulfate and also of limiting the molecular weight of polymer by reacting with one growing chain to terminate it and to initiate growth of another chain. This use of mercaptan as a chain transfer agent or modifier is of great commercial importance in the manufacture of SBR in emulsion since it allows control of the toughness of the rubber which otherwise may limit processibility in the factory.
A standard polymerization recipe agreed on for industrial use is known as the “mutual,” “standard,” “GR-S” or “hot” recipe. This standard polymerization recipe contains the following ingredients (based upon parts by weight): 75.0 parts of 1,3-butadiene, 25 parts of styrene, 0.5 parts of n-dodecyl mercaptan, 0.3 parts of potassium peroxydisulfate, 5.0 parts of soap flakes and 180.0 parts of water.
When this standard recipe is employed in conjunction with a polymerization temperature of 50° C., the rate of conversion to polymer occurs at 5-6 percent per hour. Polymerization is terminated at 70-75 percent conversion since high conversions led to polymers with inferior physical properties, presumably because of crosslinking in the latex particle to form microgel or highly branched structures. This termination is effected by the addition of a “shortstop” such as hydroquinone (about 0.1 part by weight) which reacts rapidly with radicals and oxidizing agents. Thus, the shortstop destroys any remaining initiator and also reacts with polymer-free radicals to prevent formation of new chains. The unreacted monomers are then removed; first, the butadiene by flash distillation at atmospheric pressure, followed by reduced pressure and then the styrene by steam-stripping in a column.
A dispersion of antioxidant is typically added (1.25 parts) to protect the SBR from oxidation. The latex can then be partially coagulated (creamed) by the addition of brine and then fully coagulated with dilute sulfuric acid or aluminum sulfate. The coagulated crumb is then washed, dried and baled for shipment. One of the first major improvements on the basic process was the adoption of continuous processing. In such a continuous process, the styrene, butadiene, soap, initiator and activator (an auxiliary initiating agent) are pumped continuously from storage tanks into and through a series of agitated reactors maintained at the proper temperature at a rate such that the desired degree of conversion is reached at the exit of the last reactor. Shortstop is then added, the latex is warmed by the addition of steam and the unreacted butadiene is flashed off. Excess styrene is then steam-stripped off and the latex is finished, often by blending with oil, creaming, coagulating, drying and bailing. For further details on SBR and the “standard recipe,” see The Vanderbilt Rubber Handbook, George G Winspear (Editor), R T Vanderbilt Company, Inc (1968) at pages 34-57.
U.S. Pat. No. 5,583,173 discloses a process for preparing a latex of styrene-butadiene rubber which comprises (1) charging water, a soap system, a free radical generator, 1,3-butadiene monomer and styrene monomer into a first polymerization zone; (2) allowing the 1,3-butadiene monomer and the styrene monomer to copolymerize in the first polymerization zone to a monomer conversion which is within the range of about 15 percent to about 40 percent to produce a low conversion polymerization medium; (3) charging the low conversion polymerization medium into a second polymerization zone; (4) charging an additional quantity of 1,3-butadiene monomer and an additional quantity of styrene monomer into the second polymerization zone; (5) allowing the copolymerization to continue until a monomer conversion of at least about 50 percent is attained to produce the latex of styrene-butadiene rubber. This process is sometimes referred to as the FIM (feed-injection-monomer) process.
By employing the technique disclosed in U.S. Pat. No. 5,583,173, the amount of soap required to produce styrene-butadiene rubber by emulsion polymerization can be reduced by greater than 30 percent. This is advantageous because it reduces costs and is environmentally attractive. U.S. Pat. No. 5,583,173 also reports that the styrene-butadiene rubber produced by the process described therein offers advantages in that it contains lower quantities of residual soap. This reduces fatty acid bloom characteristics in final products, such as tires, and makes plies easier to adhere together during tire building procedures.
SUMMARY OF THE INVENTION
This invention is based upon the unexpected discovery that dibenzyltrithiocarbonate will act as a pure compound to effectively and consistently control molecular weight in free radical emulsion polymerizations. The polydispersity (ratio of weight average molecular weight to number average molecular weight) of polymers made using dibenzyltrithiocarbonate as a molecular weight regulator is similar to that obtained using conventional mercaptan systems. The use of dibenzyltrithiocarbonate as a molecular weight regulator in emulsion polymerizations offers the advantage of more consistent molecular weight control and a reduced level of undesirable odors.
The present invention more specifically discloses a process for controlling the molecular weight of a polymer synthesized by free radical emulsion polymerization that comprises polymerizing at least one monomer by free radical polymerization in an aqueous emulsion in the presence of dibenzyltrithiocarbonate as a molecular weight regulator.
The present invention further discloses a process for synthesizing styrene-butadiene rubber that comprises copolymerizing styrene monomer and 1,3-butadiene monomer by free radical polymerization in an aqueous emulsion in the presence of dibenzyltrithiocarbonate as a molecular weight regulator.
The present invention also reveals a process for synthesizing styrene-butadiene rubber latex which comprises the steps of (1) charging water, a soap system, a free radical generator, dibenzyltrithiocarbonate, 1,3-butadiene monomer and styrene monomer into a first polymerization zone; (2) allowing the 1,3-butadiene monomer and the styrene monomer to copolymerize in the first polymerization zone to a monomer conversion which is within the range of about 15 percent to about 40 percent to produce a low conversion polymerization medium; (3) charging the low conversion polymerization medium into a second polymerization zone; (4) charging an additional quantity of 1,3-butadiene monomer and an additional quantity of styrene monomer into the second polymerization zone; and (5) allowing the copolymerization to continue until a monomer conversion of at least about 50 percent is attained to produce the latex of styrene-butadiene rubber.
DETAILED DESCRIPTION OF THE INVENTION
Dibenzyltrithiocarbonate can be used as an agent to control the molecular weight of virtually any polymer made by emulsion polymerization in its presence. The molecular weight reduction of the polymer synthesized increases with increasing levels of the dibenzyltrithiocarbonate. In other words, greater reductions in molecular weight can be attained by using higher levels of dibenzyltrithiocarbonate.
The amount of dibenzyltrithiocarbonate used will typically be within the range of about 0.05 to 1.0 phm. The amount of dibenzyltrithiocarbonate used will more typically be within the range of about 0.20 to 0.30 phm. The amount of dibenzyltrithiocarbonate used will preferably be within the range of about 0.23 to 0.29 phm.
The polymers made utilizing the technique of this invention have a polydispersity of greater than 2.0. The polymers made using the technique of this invention typically have a polydispersity of at least 2.5. The polymers made using the technique of this invention more typically have a polydispersity of at least 3.0.
Conventional emulsion polymerization techniques can be used in the practice of this invention with the polymerization simply being conducted in the presence of the dibenzyltrithiocarbonate. In other words, the dibenzyltrithiocarbonate can be substituted for the chain transfer agents that are conventionally utilized in such emulsion polymerizations. For instance, styrene-butadiene rubber (SBR) can be synthesizing by employing standard free radical emulsion polymerizations techniques with the exception that the polymerization is conducted in the presence of dibenzyltrithiocarbonate.
SBR can be synthesized in accordance with this invention by utilizing the general free radical emulsion polymerization technique described in U.S. Pat. No. 5,583,173 with the polymerization being carried out in the presence of the dibenzyltrithiocarbonate. This polymerization technique is known as the FIM process (feed-injection-monomer
The FIM process can be carried out in accordance with this invention by adding styrene monomer, 1,3-butadiene monomer, water, a free radical generator, dibenzyltrithiocarbonate, and a soap system to a first polymerization zone to form an aqueous polymerization medium. The first polymerization zone will normally be a reactor or series of two or more reactors. Copolymerization of the monomers is initiated with the free radical generator. This copolymerization reaction results in the formation of a low conversion polymerization medium.
At the point where the low conversion polymerization medium reaches a monomer conversion which is within the range of about 15 percent to about 40 percent, the low conversion polymerization medium is charged into a second polymerization zone. The second polymerization zone can be a reactor or a series of two or more reactors. In any case, the second polymerization zone is subsequent to the first polymerization zone. The low conversion polymerization medium will normally be charged into the second polymerization zone at a monomer conversion level that is within the range of about 17 percent to about 35 percent. It will more preferably be charged into the second polymerization zone at a level of monomer conversion which is within the range of 20 percent to 30 percent.
Additional styrene monomer and butadiene monomer are charged into the second polymerization zone. Normally, from about 20 percent to about 50 percent of the total amount of styrene monomer and 1,3-butadiene monomer will be charged into the second polymerization zone (from 50 percent to 80 percent of the total monomers are charged into the first polymerization zone). It is normally preferred to charge from about 30 weight percent to about 45 weight percent of the total quantity of monomers charged into the second polymerization zone (from 55 percent to 70 percent of the total monomers charged will be charged into the first polymerization zone). It is generally most preferred to charge from about 35 weight percent to about 42 weight percent of the total quantity of monomers charged into the second polymerization zone (from 58 percent to 65 percent of the total monomers charged will be charged into the first polymerization zone). By splitting the monomer charge between the first polymerization zone and the second polymerization zone, the total quantity of soap required to provide a stable latex is reduced by at least about 30 percent.
The copolymerization in the second polymerization zone is allowed to continue until a monomer conversion of at least 50 percent is attained. The copolymerization will preferably be allowed to continue until a total monomer conversion that is within the range of 50 percent to 68 percent is realized. More preferably, the copolymerization in the second reaction zone will be allowed to continue until a monomer conversion of 58 percent to 65 percent is reached.
In synthesizing the SBR latex, generally from about 1 weight percent to about 50 weight percent styrene and from about 50 weight percent to about 99 weight percent 1,3-butadiene are copolymerized. However, it is contemplated that various other vinyl aromatic monomers can be substituted for the styrene in the SBR. For instance, some representative examples of vinyl aromatic monomers that can be substituted for styrene and copolymerized with 1,3-butadiene in accordance with this invention include 1-vinylnaphtalene, 3-methylstyrene, 3,5-diethylstyrene, 4-propylstyrene, 2,4,6-trimethylstyrene, 4-dodecylstyrene, 3-methyl-5- normal-hexylstyrene, 4-phenylstyrene, 2-ethyl-4-benzylstyrene, 3,5-diphenylstyrene, 2,3,4,5-tetraethyl-styrene, 3-ethyl-I -vinylnaphthalene, 6-isopropyl- 1-vi nylnaphthalene, 6-cyclohexyl-1-vinylnaphthalene, 7-dodecyl-2-vinylnaphthalene, a-methylstyrene and the like. The SBR will typically contain from about 5 weight percent to about 50 weight percent bound styrene and from about 50 weight percent to about 95 weight percent bound butadiene. It is typically preferred for the SBR to contain from about 20 weight percent to about 30 weight percent styrene and from about 70 weight percent to about 80 weight percent 1,3-butadiene. It is normally most preferred for SBR to contain from about 22 weight percent to about 28 weight percent styrene and from about 72 weight percent to about 78 weight percent 1,3-butadiene. Like ratios of styrene monomer and butadiene monomer will accordingly be charged into the first polymerization zone and the second polymerization zone.
Essentially any type of free radical generator can be used to initiate such free radical emulsion polymerizations. For example, free radical generating chemical compounds, ultra-violet light or radiation can be used. In order to ensure a satisfactory polymerization rate, uniformity and a controllable polymerization, free radical generating chemical agents which are water- or oil-soluble under the polymerization conditions are generally used with good results.
Some representative examples of free radical initiators which are commonly used include the various peroxygen compounds such as potassium persulfate, ammonium persulfate, benzoyl peroxide, hydrogen peroxide, di-t-butyl peroxide, dicumyl peroxide, 2,4-dichlorobenzoyl peroxide, decanoyl peroxide, lauryl peroxide, cumene hydroperoxide, p-menthane hydroperoxide, t-butyl hydroperoxide, acetyl acetone peroxide, dicetyl peroxydicarbonate, t-butyl peroxyacetate, t-butyl peroxymaleic acid, t-butyl peroxybenzoate, acetyl cyclohexyl sulfonyl peroxide, and the like; the various azo compounds such as 2-t-butylazo-2-cyanopropane, dimethyl azodiisobutyrate, azodiisobutyronitrile, 2-t-butylazo-1-cyanocyclohexane, 1-t-amylazo-1-cyanocyclohexane, and the like; the various alkyl perketals, such as 2,2-bis-(t-butylperoxy)butane, ethyl 3,3-bis(t-butylperoxy)butyrate, 1,1-di-(t-butylperoxy) cyclohexane, and the like. Persulfate initiators, such as potassium persulfate and ammonium persulfate, are especially useful in such aqueous emulsion polymerizations.
The amount of initiator employed will vary with the desired molecular weight of the SBR being synthesized. Higher molecular weights are achieved by utilizing smaller quantities of the initiator and lower molecular weights are attained by employing larger quantities of the initiator. However, as a general rule, from 0.005 to 1 phm (parts by weight per 100 parts by weight of monomer) of the initiator will be included in the reaction mixture. In the case of metal persulfate initiators, typically from 0.1 phm to 0.5 phm of the initiator will be employed in the polymerization medium. The molecular weight of the SBR produced is, of course, also dependent upon the amount of chain transfer agent, such as t-dodecyl mercaptan, present during the polymerization. For instance, low molecular weight SBR can be synthesized by simply increasing the level of chain transfer agent. As a specific example, in the synthesis of high molecular weight SBR, the amount of t-dodecyl mercaptan used can be within the range of about 0.125 phm to about 0.150 phm. Low molecular weight SBR can be produced by simply increasing the level of t-dodecyl mercaptan present during the polymerization. For instance, the presence of 0.38 phm to 0.40 phm of t-dodecyl mercaptan will typically result in the synthesis of a low molecular weight SBR.
The soap systems used in the FIM emulsion polymerization process typically contain a combination of rosin acid and fatty acid emulsifiers. The weight ratio of fatty acid soaps to rosin acid soaps will be within the range of about 50:50 to 90:10. It is normally preferred for the weight ratio of fatty acid soaps to rosin acid soaps to be within the range of 60:40 to 85:15. It is normally more preferred for the weight ratio of fatty acid soaps to rosin acid soaps to be within the range of 75:25 to 82:18. All of the soap is charged into the first polymerization zone. The total amount of soap employed will be less than 3.5 phm. The quantity of soap employed will normally be within the range of about 2.5 phm to 3.2 phm. It is typically preferred to utilize a level of soap which is within the range of about 2.6 phm to about 3.0 phm. In most cases, it will be most preferred to use an amount of the soap system that is within the range of about 2.7 phm to 2.9 phm. The precise amount of the soap system required in order to attain optimal results will, of course, vary with the specific soap system being used. However, persons skilled in the art will be able to easily ascertain the specific amount of soap system required in order to attain optimal results.
The free radical emulsion polymerization will typically be conducted at a temperature that is within the range of about 35° F. (2° C.) to about 65° F. (18° C.). It is generally preferred for the polymerization to be carried out at a temperature that is within the range of 40° F. (4° C.) to about 60° F. (16° C.). It is typically more preferred to utilize a polymerization temperature that is within the range of about 45° F. (7° C.) to about 55° F. (13° C.). To increase conversion levels, it can be advantageous to increase the temperature as the polymerization proceeds.
After the desired monomer conversion is reached in the second polymerization zone, the SBR latex made is removed from the second polymerization zone and a short stop is added to terminate the copolymerization. The emulsion SBR can then be recovered from the latex by using standard coagulation and drying techniques. SBR made by this process can then be employed in manufacturing tires and a wide variety of other rubber articles.
This invention is illustrated by the following examples that are merely for the purpose of illustration and are not to be regarded as limiting the scope of the invention or the manner in which it can be practiced. Unless specifically indicated otherwise, all parts and percentages are given by weight.
EXAMPLE 1
In this experiment dibenzyltrithiocarbonate was synthesized by a two step process. In the first step sodium trithiocarbonate was prepared by charging 585 grams of hydrated sodium sulfide (4.5 moles), 1.5 liter of water, 30 grams of a 75% aqueous solution of methyltributylammonium chloride, and 354 grams carbon disulfide (4.6 moles) into a 4 liter flask equipped with a magnetic stirrer and thermometer. Reaction mixture was stirred for 60 minutes during which time it exothermed to 35° C. The solution turned bright red as sodium trithiocarbonate formed.
In the second step dibenzyltrithiocarbonate was prepared by adding 1008 grams of benzyl chloride (8 moles) over a period of 15 minutes to the same reactor containing the sodium trithiocarbonate solution. The reaction mixture exothermed to 50° C. It was stirred for 180 minutes and then heated to 70° C. for 30 additional minutes. To drive the reaction to completion a second catalyst charge containing 15 grams of methyltributylammonium chloride solution was added. The reaction was stirred over night without heating. The water phase was then decanted off. Two liters of ethanol was added to the semi-solid yellow product. The crystalline product was filtered, washed with ethanol and air-dried. A yield of 972 grams (83.6%) was attained. It was determined by GC to have a purity 99.7%. Material prepared by this technique was used in all experiments.
EXAMPLE 2
In this series of experiments 287.4 grams of RO (reverse osmosis) treated water, 0.39 grams of tripotassium phosphate, 44.4 grams of the potassium salt of mixed hydrogenated tallow fatty acid (10% weight solution in water), 3.7 grams of the potassium salt of disproportionated tall oil rosin acid (20% weight solution in water), 0.81 grams of the sodium salt of condensed naphthalene sulfonic acid (47.5% active), 1.02 grams of the sodium salt of linear dodecylbenzenesulfonic acid (23% active), and 0.03 grams of sodium hydrosulfite were added to 750-ml. bottles. Next, 52.7 grams of styrene and 0.53 gms. of tert-dodecyl mercaptan were added for the A bottles. Then, 8.5 grams of RO treated water, 0.03 gm. of sodium ferric ethylenediaminetetraacetate (Hampshire Chemical Co.), and 0.07 gm. of sodium formaldehyde sulfoxylate were added. Finally, 117.3 grams of 1,3-butadiene was added. The bottles were cooled to 55° F. in a tumbling water bath and 0.19 gm. of pinane hydroperoxide (44% active) was added. The same charging procedure was used for the B and C bottles with the exception that 0.34 grams and 0.68 grams of benzyldithiobenzoate, respectively, were used in place of the tert-dodecylmercaptan. For bottle D and bottle E, 0.43 grams and 0.60 grams of dibenzyltrithiocarbonate, respectively, were used in place of the tert-dodecylmercaptan. Duplicate bottles were run for each experiment. The polymerizations were carried out for the specified times. After 4 hours, the original amount of the ferric ethylenediaminetetraacetate, sodium sulfoxylate solution and pinane hydroperoxide were added to Bottles B, C, D, E to increase the polymerization rate. The A bottles were shortstopped after 4.5 hours at 65% conversion with 8.5 grams of RO water, 2.13 grams of sodium dimethyldithiocarbamate (40% active), and 0.10 gm. of diethylhydroxylamine (85% active). All of the other bottles were shortstopped after 9-10 hours at a 65% conversion with the same amount of shortstop. The duplicate bottles of each type were combined and 1000 ml of water being added. The latices were vacuum stripped (22 in. Hg, 120° F.) to remove residual monomers by removing 1000 ml of distillate. To 500 grams of the remaining latex of each, 2.3 grams of 60% Wingstay® C antioxidant emulsion and 3.5 grams of 40% Polygard antioxidant emulsion were added, and the latex was coagulated in 3000 grams of water containing 30 grams of sodium chloride, 3 grams ethyleneamine mixture, and sulfuric acid. The rubber crumb was washed with water and dried in a forced air oven. Data obtained on the rubber crumb is shown in Table I.
TABLE I
Mooney Viscosity
Bound Styrene
GPC
Polymer
(100° C.)
(FTIR)
Mw
Mn
Mw/Mn
A
45
22.9%
333,000
103,000
3.24
B
155
26.0%
C
151
23.0%
D
60
25.0%
516,000
183,000
2.82
E
30
23.1%
274,000
89,000
3.08
Rubber samples B and C contained some gel.
EXAMPLE 3
To a 10-gallon reactor, 33.9 pounds of RO water (reverse osmosis treated), 20.9 grams of tripotassium phosphate, 5.24 pounds of the potassium salt of mixed hydrogenated tallow fatty acid (10% weight solution in water), 198 grams of the potassium salt of disproportionated tall oil rosin acid (20% weight solution in water), 43.3 grams of the sodium salt of condensed napthalene sulfonic acid (47.5% active), and 54.6 grams of the sodium salt of linear dodecylbenzene sulfonic acid (23% active) were added. The pH of the aqueous solution was adjusted to 10.2-10.8. Next, a solution of 455 grams of RO water, 1.82 grams of sodium ferric ethylenediamine tetraacetate (Hampshire Chemical Co.), and 4.0 grams of sodium formaldehyde sulfoxylate was added. Then, 1747 grams of styrene and 12 grams of tert-dodecylmercaptan were added. Next, 8.19 pounds of 1,3-butadiene was added. The mixture was stirred with two AFT agitator blades at 250 rpm while cooling the contents to 50° F. Next, 10.3 grams pinane hydroperoxide (44% active) was added. When the polymer conversion reached about 30%, 1165 grams of styrene, 8.0 grams of tert-dodecyl mercaptan, and 5.46 pounds of 1,3-butadiene were added. The polymerization was continued at 50° F. until 65% conversion (5.5 hours), and then was shortstopped with a solution of 728 grams of RO water, 2.9 grams potassium hydroxide, 6.83 grams of sodium dimethyldithiocarbamate (40% active), and 3.2 grams of diethylhydroxylamine (85% active). The latex was steam stripped for 3 hours under vacuum at 120° F. latex temperature. A sample of the latex was coagulated using the sodium chloride/sulfuric acid coagulation method described in Example 2. Properties on the dry rubber crumb are shown in Table II.
A second 10-gallon reactor run was made similarly with the following changes. Sodium hydrosulfite (1.82 gms.) was added to the surfactant solution. The activator solution consisted of 455 grams of RO water, 3.64 grams of sodium ferric ethylenediamine tetraacetate, and 8 grams of sodium formaldehyde sulfoxylate. Instead of tert-dodecylmercaptan, 13.65 grams of dibenzyltrithiocarbonate was used. In this experiment, 20.7 grams of pinane hydroperoxide was used. At 30% conversion, 9.1 grams of dibenzyltrithiocarbonate was added in the styrene/butadiene mixture in place of the tert-dodecylmercaptan. At about 33% conversion, a solution of 2.28 grams of RO water, 1.82 grams sodium ferric ethylenediaminetetraacetate, and 4.0 grams of sodium formaldehyde sulfoxylate was added followed by 10.3 grams of pinane hydroperoxide to increase the polymerization rate. Again at about 58% polymer conversion, a solution of 152 grams of RO water, 1.2 grams sodium ferric ethylenediaminetetraacetate, and 2.67 grams of sodium formaldehyde sulfoxylate was added along with 6.9 grams of pinane hydroperoxide. The polymerization was shortstopped after 10.5 hours at 65% conversion using the same amount of shortstopping agents as in the prior 10-gallon run. Table II lists some of the properties of the resulting two styrene/butadiene rubbers.
TABLE II
10-Gallon Reactor - SBR Rubbers
Mooney
Bound
Polymer
Viscosity
Styrene
GPC
Modifier
(100° C.)
FTIR
Mw
Mn
Mw/Mn
tert-dodecyl
45
22.6%
318,000
110,000
2.89
mercaptan
Dibenzyltrithio-
43
23.5%
339,000
135,000
2.51
Carbonate
EXAMPLE 4
In this series of experiments, 282 grams of RO treated water, 0.30 grams of Tamol SN surfactant, 0.75 grams of tripotassium phosphate, 19.6 grams of the potassium salt of disproportioned tall oil rosin acid (20% weight solution in water), 35.7 grams of the sodium salt of mixed hydrogenated tallow fatty acid (10% weight solution in water), and 0.03 grams of sodium hydrosulfite were added to 750-ml bottles. Then, 8.5 grams. of RO treated water, 0.03 grams of sodium ferric ethylenediaminetetraacetate (Hampshire Chemical Co.), and 0.07 grams of sodium formaldehyde sulfoxylate were added to the bottles. Next, 52.7 grams of styrene and 0.53 grams of tert-dodecylmercaptan were added for the A bottles. Finally, 117.3 grams of 1,3-butadiene was added. The bottles and contents were cooled to 50° F., and 0.19 gm. of pinane hydroperoxide (44% active) was added. The same charging procedure was used for the B and C bottles except 0.43 grams and 0.60 grams of 1-phenylethyldithiobenzoate, respectively, were used in place of tert-dodecylmercaptan. Also, the activator solution was changed to 8.5 grams of RO treated water, 0.07 grams of sodium ferric ethylenediaminetetraacetate, and 0.15 grams of sodium formaldehyde sulfoxylate and the initiator to 0.39 grams of pinane hydroperoxide (44% active). Duplicate bottles were run for each. The polymerizations were carried out for the specified times. After 4 hours. and 65% polymer conversion, the A bottles were shortstopped with a mixture of 8.5 grams RO water, 2.13 grams of sodium dimethyldithiocarbamate(40% active), and 0.10 grams diethylhydroxylamine (85% active). The B bottles were shortstopped after 7 hours at 65% conversion and the C bottles after 9.75 hours at 65% conversion. The latices were vacuum stripped, coagulated, and dried to crumb rubbers according to the procedure described in Example 2. Data on the crumb rubbers is shown in Table III.
TABLE III
Data on SBR Rubbers
Polymer
Mooney Viscosity (100° C.)
A
30
B
153
C
149
While certain representative embodiments and details have been shown for the purpose of illustrating the subject invention, it will be apparent to those skilled in this art that various changes and modifications can be made therein without departing from the scope of the subject invention. | Mercaptans are normally used as chain transfer agents in emulsion polymerizations. The mercaptans used in commercial applications are typically complex mixtures of hundreds of similar compounds having boiling points within a narrow range. The chain transfer activity of different mercaptans with such mixtures can vary substantially. To further complicate the situation, the distribution of various mercaptans can also vary substantially between lots of material obtained from commercial sources. Thus, consistent molecular weight control is typically difficult to attain in free radical emulsion polymerizations. This invention is based upon the unexpected discovery that dibenzyltrithiocarbonate will act as a pure compound to effectively and consistently control molecular weight in free radical emulsion polymerizations. The polydispersity of polymers made using dibenzyltrithiocarbonate as a molecular weight regulator is similar to that obtained using conventional mercaptan systems. This invention more specifically discloses a process for controlling the molecular weight of a polymer synthesized by free radical emulsion polymerization that comprises polymerizing at least one monomer by free radical polymerization in an aqueous emulsion in the presence of dibenzyltrithiocarbonate. For instance, dibenzyltrithiocarbonate can be used as a molecular weight regulator in the synthesis of styrene-butadiene rubber by emulsion polymerization. Accordingly, this invention further discloses a process for synthesizing styrene-butadiene rubber (SBR) that comprises copolymerizing styrene monomer and 1,3-butadiene monomer by free radical polymerization in an aqueous emulsion in the presence of dibenzyltrithiocarbonate. The use of dibenzyltrithiocarbonate is inherently less odorous than the use of mercaptans. | 2 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to the field of server provisioning and more particularly to server provisioning to heterogeneous target platforms and/or heterogeneous tasks.
[0003] 2. Description of the Related Art
[0004] The enterprise has evolved over the past two decades from the smallest of peer to peer networks running multi-user applications without coordination, to massive distributed computing systems involving dozens of servers and thousands of clients across a vast geographical expanse. In the earlier days of enterprise class computing, deploying multi-user applications often involved nothing more than installing an application in a centralized location and providing communicative access to the different users over a small, computer communications network. Evolved configurations involved client-server computing where the power of the client computers could be exploited to support the execution of the application logic and the application data could be served from a central location.
[0005] The demands of modern enterprise class computing require more than simplistic client-server arrangements and involve the distributed deployment of multiple applications and application components across multiple different servers in different local networks banded together over a wide area utilizing high speed broadband communicative links. Creating an enterprise environment for single installation can be treated as a laboratory experiment and trial-and-error tactics rule the day. Where the installation must be repeated with consistency across installations, however, a more coordinated approach must be followed. A coordinated approach particularly can be important where customers receive the installation or the application itself as a product or service. In this circumstance, customers cannot tolerate an imperfect installation or an installation that appears to be more of a laboratory experiment than a coordinated effort.
[0006] Generally speaking, within the enterprise class environment, the coordinated installation of an application across one or more server computing platforms in a repeatable fashion has come to be known as “server provisioning” borrowing a term from the field of telecommunications. Server provisioning literally implies the deployment of an application onto a host computing platform in a coordinated and repeatable fashion. In the simplified provisioning exercise, an operator installs and configures the various applications in the host computing platform according to a pre-defined installation plan ordinarily specified by an application manufacturer or a systems integrator.
[0007] In as much as only a single host computing platform and host operating systems are to be considered in the course of the simplified provisioning exercise, the process can be relatively straightforward. In the larger enterprise, however, the process can be quite complex. So complex has server provisioning become, several manufacturers have developed automated tools for managing the server provisioning process. In conventional server provisioning tools, a set of applications and applications can be configured in a master arrangement and the master arrangement can be replicated to a target platform. Unfortunately, conventional server provisioning tools rely heavily on the nature of the target platform and are hardwired to a specified platform. To that end, conventional server provisioning tools are ill-equipped to handle heterogeneous computing environments including multiple different target platform types.
BRIEF SUMMARY OF THE INVENTION
[0008] Embodiments of the present invention address deficiencies of the art in respect to server provisioning in a heterogeneous computing environment and provide a novel and non-obvious method, system and computer program product for secure and verified distributed orchestration and provisioning. In one embodiment of the invention, a server provisioning method can be provided. The server provisioning method can include establishing grouping criteria, grouping different target computing nodes into different groups of target computing nodes according to the established grouping criteria, server provisioning a root node in each of the different groups of target computing nodes, and relying upon the root node in each of the different groups to peer-to-peer server provision remaining nodes in each of the different groups.
[0009] Establishing grouping criteria can include establishing grouping criteria according to a type of target node, a type of server provisioning task, or both. In particular, grouping different target computing nodes into different groups of target computing nodes according to the established grouping criteria can include computing a detailed provisioning task value for each of the target computing nodes indicating a presence and an absence of different components required for server provisioning each of the target computing nodes, and grouping sets of the target computing nodes having similar detailed provisioning task values.
[0010] Utilizing the detailed provisioning task value, server provisioning a root node in each of the different groups of target computing nodes can include assembling a bundle for distribution to the root node for each of the different groups of target computing nodes, the bundle including in each instance a set of components required for server provisioning target nodes in a respective group of target nodes. Thereafter, the bundle can be forwarded to the root node.
[0011] Finally, relying upon the root node in each of the different groups to peer-to-peer server provision remaining nodes in each of the different groups can include specifying a threshold for available bandwidth and a maximum random delay time for use by peer-to-peer provisioning logic in the root node in determining when to server provision the remaining nodes, and providing a bundle to the root node for distribution to each of the remaining nodes at an interval computed from the threshold and maximum random delay.
[0012] In another embodiment of the invention, a server provisioning data processing system can be provided. The system can include an orchestration and provisioning server coupled to multiple target computing nodes over a computer communications network. Each of the target computing nodes can include peer-to-peer provisioning logic including program code enabled to server provision coupled nodes at a lower hierarchical level with a bundle received from a node at a higher hierarchical level. A certificate managing authority also can be coupled to the target computing nodes.
[0013] The system further can include orchestration and provisioning logic disposed in the orchestration and provisioning server. The logic can include program code enable to group different ones of the target computing nodes into different hierarchically arranged groups of the target computing nodes according to grouping criteria, and to server provisioning a root node in each of the different groups of target computing nodes. The grouping criteria can include only target computing node type, only provisioning task type, or both target computing node type and provisioning task type.
[0014] Additional aspects of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The aspects of the invention will be realized and attained by means of the elements and combinations particularly pointed out in the appended claims. It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention, as claimed.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0015] The accompanying drawings, which are incorporated in and constitute part of this specification, illustrate embodiments of the invention and together with the description, serve to explain the principles of the invention. The embodiments illustrated herein are presently preferred, it being understood, however, that the invention is not limited to the precise arrangements and instrumentalities shown, wherein:
[0016] FIG. 1 is a schematic illustration of a computing enterprise configured for orchestrated peer-to-peer server provisioning;
[0017] FIG. 2 is a flow chart illustrating a process for orchestrated peer-to-peer server provisioning; and,
[0018] FIG. 3 is a flow chart illustrating a peer-driven process of server provisioning in the computing enterprise of FIG. 1 .
DETAILED DESCRIPTION OF THE INVENTION
[0019] Embodiments of the present invention provide a method, system and computer program product for orchestrated peer-to-peer server provisioning. In accordance with an embodiment of the present invention, different target peers in a pool of server targets in a computing enterprise can be grouped according to server provisioning requirements in a peer hierarchy. The server provisioning requirements can relate to the set of components required to be deployed onto a particular target based upon the presence and the absence of specific components required for a complete deployment. In this regard, the set of required components can vary according to the type of peer targeted to receive the deployment, the type of deployment task, or both the type of peer and the type of deployment task.
[0020] Thereafter, different server provisioning bundles can be assembled for delivery to the peers in the different groups along with a specification of the server provisioning tasks to be performed in order to complete the deployment in the target group of peers. Notably, each peer in each different group can be enabled to receive the bundle and the instructions and to further deploy the bundle and the instructions to other coupled peers at lower levels in the hierarchy. In this way, a set of target peers directly receiving a server provisioning bundle can be substantially less than the set of target peers intended to receive the server provisioning bundle and the responsibility of server provisioning can be shared with the nodes in the target group of peers.
[0021] In illustration, FIG. 1 is a schematic illustration of a computing enterprise configured for orchestrated peer-to-peer server provisioning. The computing enterprise can include multiple, heterogeneous target computing nodes 160 communicatively coupled to one another over a computer communications network. Each of the target computing nodes 160 can include computing structure and a corresponding operating system in order to enable each of the target computing nodes 160 to host and manage the execution of computing logic.
[0022] An orchestration and provisioning server 110 can be coupled to the target computing nodes 160 . The orchestration and provisioning server 110 can include knowledge of the target computing nodes 160 such as the location of each of the nodes 160 in terms of network and sub-network, the operating system hosted within each of the nodes 160 , the service pack level for each operating system, the fix pack level for each operating system, and the software installed in each of the nodes 160 , at both the application and component level. The orchestration and provisioning server 110 further can include a policy that among other parameters, defines the maximum number of servers to be provisioned linearly. The maximum number can be computed according to a number of factors, for example, the processing power of the orchestration and provisioning server 110 as compared to others of the nodes 160 , the distribution mechanism for the server provisioning task, e.g. push or pull, and the number of nodes 160 in the environment.
[0023] The orchestration and provisioning server 110 can include orchestration and provisioning program logic 200 . The orchestration and provisioning logic 200 can include program code enabled to group different ones of the target computing nodes 160 according to provisioning task requirements to fulfill server provisioning for the target computing nodes 160 . Specifically, the target computing nodes 160 can be grouped according to the number and identity of components necessary to deploy onto the target computing nodes 160 , or the type of provisioning tasks necessary to deploy selected components for server provisioning onto the target computing nodes 160 , or both. In one aspect of the invention, the number of groups can be determined according to the policy defining a maximum number of nodes 160 to be provisioned linearly.
[0024] Importantly, the program code of the orchestration and provisioning logic 200 can be further enabled to compute a set of metrics for a detailed provisioning task (DPT) 170 . The DPT 170 can specify a minimal set of components for a provisioning task and can represent the presence and the absence of different required components in a particular one of the target computing nodes 160 . The different required components can vary according to the specific type of the provisioning task, or the type of type of the particular one of the target computing nodes 160 . As an example, a value of “0” can represent the absence of a required component, while the value of “1” can represent the presence of a required component. In this way, a single value can encode the set of required components that must be installed onto a specified one of the target computing nodes 160 in order to fulfill a provisioning task.
[0025] The program code of the orchestration and provisioning logic 200 yet further can be enabled to compare the DPT 170 for each of the target computing nodes 160 in order to group clusters of the target computing nodes 160 according to similar metrics. In particular, those of the target computing nodes 160 having the most similar set of metrics in a DPT 170 can be considered to require a similar set of components in order to complete a server provisioning task. Consequently, a collection of components necessary to meet the requirements of a server provisioning task for a group of the target computing nodes 160 can be assembled in a bundle 130 , such as an Open Services Gateway Initiative (OSGI) bundle, and provided to the group for provisioning onto the target computing nodes 160 in the group.
[0026] Notably, each of the target computing nodes 160 in the group can include peer to peer provisioning (P2PP) logic 150 . The P2PP logic 150 can include program code enabled to receive the bundle 130 and apply the bundle 130 to other coupled ones of the target computing nodes 160 in the group of target computing nodes 160 . In this way, the program code of the orchestration and provisioning logic 200 need only apply the bundle 130 to a root node in the group of target computing nodes 160 . The P2PP logic 150 of the root node in the group of target computing nodes 160 in turn can apply the bundle to other nodes in the group of target computing nodes 160 and so forth.
[0027] Finally, a certificate managing authority 120 can be communicatively coupled to the orchestration and provisioning server 110 and to each of the target computing nodes 160 . The certificate managing authority 120 can be configured to verify on request the source of the bundles 130 so as to ensure a secure environment for server provisioning.
[0028] In more particular illustration of the operation of the orchestration and provisioning logic 200 , FIG. 2 is a flow chart illustrating a process for orchestrated peer-to-peer server provisioning. Beginning in block 210 , a list of target nodes can be selected for server provisioning. In block 220 , criteria for grouping the target nodes can be selected. The criteria can include the similarity in the number and type of components to be installed as compared to those components already present in the nodes. The number and type of components can vary not only according to node type (e.g. type of host operating system), but also according to task type (e.g. type of application to be installed, or installation operation that can vary from an installation to an updating to an un-installation).
[0029] In block 230 , the target nodes can be grouped according to the selected criteria limited only by the number of groups suggested by the policy. In block 240 , a first group can be selected for consideration and in block 250 , a bundle can be computed for the group. The bundle can include a collection of components and supporting files required to complete server provisioning for the nodes in the group at both the root level and levels below the root level within the hierarchy of the group. Thereafter, in block 260 the bundle can be provided to the root node for the group. The root node in turn can install the requisite components in the bundle and can provide the bundle to nodes below the root node for server provisioning therein.
[0030] In decision block 270 , if additional groups of nodes remain to be considered, in block 280 , a next group of nodes can be selected for consideration and the process can repeat through block 250 . In particular, the process can repeat for each computed group wherein each computed group receives a bundle specifically arranged to account for the type of node, the type of provisioning task, or both. When the root nodes of the groups have received and applied the bundles, reports can be generated indicating the results of each of the server provisioning tasks for each of the nodes. The reports can filter back to the orchestration and provisioning server and ultimately can be stored in block 290
[0031] As the P2PP logic in the nodes within each group receive a bundle for distribution to other nodes at lower hierarchical levels, the program code of the P2PP logic can undertake measures to avoid network overloading in the course of peer-to-peer distributing the bundles. In particular, as shown in FIG. 3 , beginning in block 310 a node can receive a bundle for use in server provisioning. In block 320 , a random period of time can elapse subsequent to which in block 330 , the traffic on the network can be sensed to determine available network bandwidth. The random period of time can be specified by the provisioning server along with the receipt of the bundle.
[0032] In decision block 340 , if sufficient network bandwidth exists, in block 350 the bundle can be provisioned to the next set of nodes at a lower level in the nodal hierarchy within the set of grouped target computing nodes. Thereafter, in block 360 , a resulting report can be received from each of the nodes in the next set of nodes and reported back to a provisioning node at a higher hierarchical level in block 270 . In this way, each of the nodes at each level in the hierarchy can share in the burden of performing the provisioning task without requiring the provisioning server to provision each node in the hierarchy sequentially.
[0033] Embodiments of the invention can take the form of an entirely hardware embodiment, an entirely software embodiment or an embodiment containing both hardware and software elements. In a preferred embodiment, the invention is implemented in software, which includes but is not limited to firmware, resident software, microcode, and the like. Furthermore, the invention can take the form of a computer program product accessible from a computer-usable or computer-readable medium providing program code for use by or in connection with a computer or any instruction execution system.
[0034] For the purposes of this description, a computer-usable or computer readable medium can be any apparatus that can contain, store, communicate, propagate, or transport the program for use by or in connection with the instruction execution system, apparatus, or device. The medium can be an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system (or apparatus or device) or a propagation medium. Examples of a computer-readable medium include a semiconductor or solid state memory, magnetic tape, a removable computer diskette, a random access memory (RAM), a read-only memory (ROM), a rigid magnetic disk and an optical disk. Current examples of optical disks include compact disk—read only memory (CD-ROM), compact disk—read/write (CD-R/W) and DVD.
[0035] 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, 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 during execution. 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. | Embodiments of the present invention address deficiencies of the art in respect to server provisioning in a heterogeneous computing environment and provide a method, system and computer program product for secure and verified distributed orchestration and provisioning. In one embodiment of the invention, a server provisioning method can be provided. The server provisioning method can include establishing grouping criteria, grouping different target computing nodes into different groups of target computing nodes according to the established grouping criteria, server provisioning a root node in each of the different groups of target computing nodes, and relying upon the root node in each of the different groups to peer-to-peer server provision remaining nodes in each of the different groups. | 7 |
RELATED APPLICATIONS
This application claims priority under 35 U.S.C. §119 to Japanese Patent Application No. 2009-227463 filed on Sep. 30, 2009, the entire content of which is hereby incorporated by reference.
FIELD OF THE INVENTION
The present invention relates to a blood sample processing apparatus and a blood sample processing method.
BACKGROUND OF THE INVENTION
Conventionally, blood sample processing apparatuses have been known in which an aspiration tube penetrates a lid (cap) for sealing a specimen container to aspirate the blood sample in the specimen container and the aspirated blood sample is processed.
Among such blood sample processing apparatuses, there is an apparatus which repeatedly performs an inclining-stirring operation, in which a specimen container held in an upright state is rotated to be in an inclining state such that a bottom portion of the specimen container is positioned higher than a lid, and then is returned to its original upright state, and then which aspirates a blood sample to carry out analysis.
For example, a sample analysis apparatus described in U.S. Patent Publication No. 2007/110627 is provided with a hand member for holding a specimen container and a driver for rotating the hand member, and performs an inclining-stirring operation of the specimen container by rotating the hand member holding the specimen container before aspirating a blood sample from the specimen container by an aspiration tube.
The pressure inside the specimen container is higher than the pressure of the atmosphere, therefore, in the blood sample processing apparatus which performs such an inclining-stirring operation, the blood sample may be aspirated after opening the inside of the specimen container to the atmosphere in order to secure the quantitative precision in aspirating a blood sample by the aspiration tube.
The opening to the atmosphere is performed by various methods, and for example, there is an apparatus which uses an aspiration tube having a groove extending in a longitudinal direction in an outer circumferential surface thereof to open the inside of a specimen container to the atmosphere before aspirating a blood sample by the aspiration tube. In such an apparatus, when the aspiration tube penetrates the lid of the specimen container, the inside of the specimen container is opened to the air via the groove and thus the inside of the specimen container can be opened to the atmosphere.
However, when performing an inclining-stirring operation of a specimen container as in the sample analysis apparatus described in U.S. Patent Publication No. 2007/110627, a blood sample may adhere to the back side of the lid of the specimen container in accordance with the lid type. The pressure in the sealed specimen container is higher than the pressure of the atmosphere as described above. Accordingly, when an aspiration tube having a groove extending in a longitudinal direction in an outer circumferential surface thereof penetrates the lid of the specimen container in a state in which the blood sample adheres to the back side of the lid, the blood sample adhering to the back side of the lid may leak from the upper surface of the lid through the groove of the aspiration tube.
SUMMARY OF THE INVENTION
The scope of the present invention is defined solely by the appended claims, and is not affected to any degree by the statements within this summary.
A first aspect of the present invention is a blood sample processing apparatus comprising: a container holder securing a sample container that contains a blood sample, the sample container having a lid, the container holder coupled to a rotation driver that longitudinally rotates the sample container; a sample aspirator that aspirates the blood sample in the sample container; and a controller that operates the rotation driver and the sample aspirator, wherein the controller commands the rotation driver to repeatedly perform an inclining-stirring operation that includes a first process and a second process, wherein in the first process, the sample container is initially held in an upright position by the container holder and then rotated to an inclined position, and in the second process, the inclined sample container is returned to the upright position, and wherein in a final inclining-stirring operation, the second process is carried out for a longer time than previous second processes, and wherein the controller commands the sample aspirator to aspirate the blood sample in the sample container after the second process of the final inclining-stirring operation.
A second aspect of the present invention is a blood sample processing method comprising: stirring a blood sample in a sample container, the sample container having a lid; and aspirating the blood sample in the sample container after stirring, wherein the stirring comprises an repeated inclining-stirring operation that includes a first process and a second process, wherein in the first process, the sample container is moved from an upright position to an inclined position, and in the second process, the sample container is moved from an inclined position to an upright position, and wherein the second process of a final inclining-stirring operation is performed for a longer time than previous second processes.
A third aspect of the present invention is a blood sample processing apparatus comprising: a container holder securing a sample container that contains a blood sample, the sample container having a lid, the container holder coupled to a rotation driver that longitudinally rotates the sample container while the sample holder holds the sample container; a sample aspirator that aspirates the blood sample in the sample container; and a controller that operates the rotation driver and the sample aspirator, wherein the controller commands the rotation driver to perform an inclining-stirring operation that includes a first process and a second process, wherein in the first process, the sample container is initially held in an upright position by the container holder and then rotated to an inclined position, and in the second process, the inclined sample container is returned to the upright position wherein the second process is carried out for at least about 0.8 seconds, and wherein the controller commands the sample aspirator to aspirate the blood sample in the sample container after performing the second process.
A fourth aspect of the present invention is a blood sample processing method comprising: stirring a blood sample in a sample container, the sample container having a lid; and aspirating the blood sample in the sample container, wherein the stirring comprises an inclining-stirring operation that includes a first process and a second process, wherein in the first process, the sample container is moved from an upright position to an inclined position, and in the second process, the sample container is moved from an inclined position to an upright position, and wherein the second process is performed for at least about 0.8 seconds.
A fifth aspect of the present invention is a blood sample processing apparatus comprising: a container holder securing a sample container that contains a blood sample, the sample container having a lid, the container holder coupled to a rotation driver that longitudinally rotates the sample container; a sample aspirator that aspirated the blood sample in the sample container; and a controller that operates the rotation driver and the sample aspirator, wherein the controller commands the rotation driver to repeatedly perform an inclining-stirring operation that includes a first process and a second process, wherein in the first process, the sample container is initially held in a first state in which a bottom portion of the sample container is positioned lower than the lid and then rotated to a second state in which the bottom portion of the sample container is positioned at least as high as the lid, and wherein in the second process, the sample container is moved from the second state to the first state, wherein the controller commands the rotation driver to perform the second process of a final inclining-stirring operation to be carried out for a longer time than other second processes, and wherein the controller commands the sample aspirator to aspirate the blood sample in the sample container after the second process of the final inclining-stirring operation.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view showing the overall configuration of an embodiment of a blood sample processing apparatus of the present invention;
FIG. 2 is a perspective view showing sections in the blood sample processing apparatus shown in FIG. 1 in detail;
FIG. 3 is a schematic explanatory diagram showing measuring units and a specimen transport apparatus of the blood sample processing apparatus shown in FIG. 1 ;
FIG. 4 is a perspective view showing the vicinity of a piercer of the blood sample processing apparatus shown in FIG. 1 ;
FIG. 5 is a perspective view showing the measuring units and the specimen transport apparatus of the blood sample processing apparatus shown in FIG. 1 ;
FIG. 6 is a block diagram for explaining a control apparatus of the blood sample processing apparatus shown in FIG. 1 ;
FIG. 7 is a perspective view of an example of a lid which is used in a specimen container, viewed from the upper side;
FIG. 8 is a perspective view of the lid shown in FIG. 7 , viewed from the lower side;
FIG. 9 is a longitudinal sectional view of the lid shown in FIG. 7 .
FIG. 10 is a diagram explaining an example of an inclining-stirring operation of the present invention;
FIGS. 11A-11C are diagrams showing transitions in which blood adhering to the back side of the lid flows to a bottom portion;
FIG. 12 is a front view showing the appearance of the piercer;
FIG. 13 is a flowchart showing the processing flow of a blood sample processing method according to the present embodiment; and
FIG. 14 is a flowchart showing the flow of a stirring operation according to the present embodiment.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Hereinafter, an embodiment of a blood sample processing apparatus and a blood sample processing method of the present invention will be described in detail with reference to the accompanying drawings.
[Blood Sample Processing Apparatus]
First, the overall configuration of a blood sample processing apparatus will be described. A blood sample processing apparatus 1 shown in FIG. 1 is a blood cell counting apparatus for counting the number of blood cells in a blood sample collected from a subject, and as shown in FIGS. 1 and 2 , is provided with two measuring units, that is, a first measuring unit 2 and a second measuring unit 3 , a specimen transport apparatus (sampler) 4 which is disposed in front of the first measuring unit 2 and the second measuring unit 3 (in a direction of the arrow Y 1 ) and a control apparatus 5 including a personal computer (PC) which is electrically connected to the first measuring unit 2 , the second measuring unit 3 and the specimen transport apparatus 4 . In addition, the blood sample processing apparatus 1 is connected to a host computer 6 (see FIG. 3 ) by the control apparatus 5 .
In addition, as shown in FIGS. 1 to 3 , the first measuring unit 2 and the second measuring unit 3 are substantially the same type of measuring unit and are disposed so as to be adjacent to each other. In greater detail, in this embodiment, the second measuring unit 3 uses the same measurement principle as that of the first measuring unit 2 to measure the same measurement items of a specimen. Further, the second measuring unit 3 also measures the measurement items which are not analyzed by the first measuring unit 2 . In addition, as shown in FIG. 3 , each of the first measuring unit 2 and the second measuring unit 3 includes a piercer 211 ( 311 ) which aspirates blood as a specimen from a specimen container 101 , a sample preparation section 22 ( 32 ) which prepares a sample for detection from the blood aspirated by the piercer 211 ( 311 ), and a detecting section 23 ( 33 ) which detects blood cells of the blood from the sample for detection prepared by the sample preparation section 22 ( 32 ).
Each of the first measuring unit 2 and the second measuring unit 3 further includes a unit cover 24 ( 34 ) which stores the sample preparation section 22 ( 32 ) and the like, a specimen container transport section 25 ( 35 ) which introduces a specimen container 101 to the inside of the unit cover 24 ( 34 ) and transports the specimen container 101 up to a position 600 ( 700 ) (see FIG. 3 ) at which the piercer 211 ( 311 ) performs the aspiration, an existence detection section 26 ( 36 ) which detects the existence of a specimen container 101 transported to the inside by the specimen container transport section 25 ( 35 ), and a chuck section 27 ( 37 ) which fixes and holds a specimen container 101 at the aspiration position 600 ( 700 ) (see FIG. 3 ). In addition, as shown in FIGS. 1 and 2 , in the respective outer surfaces of front surface sections 241 ( 341 ) of the unit covers 24 ( 34 ), a specimen setting section opening-closing button 28 ( 38 ), a prior specimen measurement start button 29 ( 39 ) and an opening section 241 a ( 341 a ) through which a moving section 255 d ( 355 d ) (to be described later) of the specimen container transport section 25 ( 35 ) passes are provided.
FIG. 4 is a view showing the vicinity of the piercer 211 ( 311 ). As shown in FIG. 4 , the blood sample processing apparatus 1 includes the piercer 211 ( 311 ) as a specimen aspiration tube and a piercer moving section 212 ( 312 ) as a penetration driver which causes the piercer 211 ( 311 ) to penetrate the lid of a specimen container 101 . The piercer 211 ( 311 ) is formed such that the front end thereof can penetrate a sealing lid 102 (see FIGS. 7 to 9 ) (to be described later) of a specimen container 101 . Moreover, as shown in FIG. 12 , in the outer circumferential surface of the piercer 211 ( 311 ), a groove 211 a extending in a longitudinal direction of the piercer 211 ( 311 ) is formed, and when the piercer 211 ( 311 ) penetrates the lid of the specimen container 101 , the inside of the specimen container 101 is opened to the air via the above-described groove 211 a . The piercer moving section 212 ( 312 ) has a function of moving the piercer 211 ( 311 ) in a vertical direction (in a direction of the arrows Z 1 and Z 2 ). The piercer moving section 212 ( 312 ) has a horizontal arm 213 ( 313 ) which fixes and holds the piercer 211 ( 311 ), a threaded shaft 214 ( 314 ) which penetrates the horizontal arm 213 ( 313 ) in the vertical direction (in the direction of the arrows Z 1 and Z 2 ), and a nut 215 ( 315 ) which is threadably mounted on the threaded shaft 214 ( 314 ). Further, the piercer moving section 212 ( 312 ) has a slide rail 216 ( 316 ) which is disposed parallel to the threaded shaft 214 ( 314 ) (in the direction of the arrows Z 1 and Z 2 ), a sliding member 217 ( 317 ) which is slidably mounted on the slide rail 216 ( 316 ) and a stepping motor 218 ( 318 ). The horizontal arm 213 ( 313 ) is fixed to the nut 215 ( 315 ) and the sliding member 217 ( 317 ).
The detecting section 23 ( 33 ) is configured to perform RBC detection (detection of red blood cells) and PLT detection (detection of platelets) by a sheath flow DC detection method and perform HGB detection (detection of hemoglobin in blood) by a SLS-hemoglobin method. In addition, the detecting section 23 ( 33 ) is also configured to perform WBC detection (detection of white blood cells) by a flow cytometry method using a semiconductor laser.
The detection result obtained by the detecting section 23 ( 33 ) is transmitted as measurement data (measurement result) of the specimen to the control apparatus 5 . This measurement data becomes a base for the final analysis result (the number of red blood cells, the number of platelets, the amount of hemoglobin, the number of white blood cells and the like) which is provided to a user.
As shown in FIG. 5 , the specimen container transport section 25 ( 35 ) (see FIG. 3 ) has a hand section 251 ( 351 ) which is a container holder capable of holding a specimen container 101 , an opening-closing section 252 ( 352 ) which opens and closes the hand section 251 ( 351 ), a vertical moving section 253 ( 353 ) which linearly moves the hand section 251 ( 351 ) in the vertical direction (in the direction of the arrows Z 1 and Z 2 ) and a stirring motor section 254 ( 354 ) which is a rotation driver for moving (rotating) the hand section 251 ( 351 ) like a pendulum between its upright state and inclining state. The stirring motor section 254 ( 354 ) is configured to move (rotate) the hand section 251 ( 351 ) like a pendulum between its upright state and inclining state by the power generated by the stepping motor. Further, as shown in FIG. 3 , the specimen container transport section 25 ( 35 ) has a specimen container transfer section 255 ( 355 ) which substantially horizontally moves a specimen container 101 in the direction of the arrows Y 1 and Y 2 and a bar-code reading section 256 ( 356 ).
The hand section 251 ( 351 ) is disposed above the transport path of a rack 110 transported by the specimen transport apparatus 4 . In addition, the hand section 251 ( 351 ) is configured to be moved downward (in the direction of the arrow Z 2 ) when a specimen container 101 is transported to a first ejection position 43 a and a second ejection position 43 b (see FIG. 3 ) by the specimen transport apparatus 4 and to be then opened and closed by the opening-closing section 252 ( 352 ), thereby gripping the specimen container 101 stored in a rack 110 .
In addition, the hand section 251 ( 351 ) is configured to move the gripped specimen container 101 upward (in the direction of the arrow Z 1 ) to eject the specimen container 101 from the rack 110 , and then is moved like a pendulum by the stirring motor section 254 ( 354 ) (for example, reciprocated 10 times). In this manner, the hand section 251 ( 351 ) can stir the blood in the gripped specimen container 101 . After the stirring, the hand section 251 ( 351 ) is configured to open the gripping of the specimen container 101 by the opening-closing section 252 ( 352 ) after moving downward (in the direction of the arrow Z 2 ). In greater detail, the hand section 251 ( 351 ) is configured to set the specimen container 101 in a first specimen setting section 255 a ( 355 a ) which is moved to a specimen setting position 610 ( 710 ) (see FIG. 3 ) by the specimen container transfer section 255 ( 355 ). In addition, as shown in FIG. 3 , when viewed from the top, the first ejection position (specimen container ejection position) 43 a and the specimen setting position (specimen container setting position) 610 are disposed so as to overlap with each other, and the second ejection position (specimen container ejection position) 43 b and the specimen setting position (specimen container setting position) 710 are disposed so as to overlap with each other.
The opening-closing section 252 ( 352 ) is configured to open and close the hand section 251 ( 351 ) in order to grip a specimen container 101 using the power generated by an air cylinder 252 a ( 352 a ).
The vertical moving section 253 ( 353 ) is configured to move the hand section 251 ( 351 ) in the vertical direction (in the direction of the arrows Z 1 and Z 2 ) along a rail 253 b ( 353 b ) using the power generated by the stepping motor 253 a ( 353 a ).
The chuck section 27 ( 37 ) is configured to fix and hold a specimen container 101 which is transferred to the aspiration position 600 ( 700 ).
A before-analysis rack holder 41 has a rack input section 411 and is configured to push out racks 110 held in the before-analysis rack holder 41 one by one onto a rack transport section 43 by moving the rack input section 411 in the direction of the arrow Y 2 . The rack input section 411 is configured to be driven by a stepping motor (not shown) which is provided below the before-analysis rack holder 41 . In addition, the before-analysis rack holder 41 has a regulating section 412 (see FIG. 5 ) in the vicinity of the rack transport section 43 and is configured to regulate the movement of a rack 110 in order not to return the rack 110 , which is pushed out onto the rack transport section 43 once, to the inside of the before-analysis rack holder 41 .
An after-analysis rack holder 42 has a regulating section 421 (see FIG. 4 ) in the vicinity of the rack transport section 43 and is configured to regulate the movement of a rack 110 in order not to return the rack 110 , which is moved to the inside of the after-analysis rack holder 42 once, to the rack transport section 43 .
As shown in FIG. 3 , the rack transport section 43 is configured to transport a rack 110 in order to transfer a specimen container 101 held in the rack 110 to the first ejection position 43 a for providing the specimen to the first measuring unit 2 and to the second ejection position 43 b for providing the specimen to the second measuring unit 3 . Further, the rack transport section 43 is configured to transport a rack 110 in order to transfer a specimen container 101 up to a specimen existence confirmation position 43 c for confirming the existence of the specimen container 101 storing the specimen by an existence detection sensor 45 and a reading position 43 d for reading the bar-code of the specimen container 101 storing the specimen by a bar-code reading section 44 .
In addition, as shown in FIG. 5 , the rack transport section 43 has two belts, that is, a first belt 431 and a second belt 432 which can be moved independently of each other.
The existence detection sensor 45 is a contact sensor having a contact piece shaped like a short split curtain (see FIG. 5 ) 451 , a light-emitting element (not shown) emitting light and a light-receiving element (not shown). The existence detection sensor 45 is configured such that the contact piece 451 is bent by being brought into contact with a detection target material to be detected, and as a result, the light emitted from the light-emitting element is reflected by the contact piece 451 and enters the light-receiving element. In this manner, when a specimen container 101 as a detection target which is stored in a rack 110 passes under the existence detection sensor 45 , the contact piece 451 is bent by the specimen container 101 and the existence of the specimen container 101 can thus be detected.
A rack output section 46 is disposed so as to be opposed to the after-analysis rack holder 42 with the rack transport section 43 interposed therebetween, and is configured to be horizontally moved in the direction of the arrow Y 1 . In this manner, when a rack 110 is transported between the after-analysis rack holder 42 and the rack output section 46 , the rack output section 46 is moved to the after-analysis rack holder 42 side to press and move the rack 110 to the inside of the after-analysis rack holder 42 .
As shown in FIGS. 1 to 3 and 6 , the control apparatus 5 is composed of a personal computer (PC) or the like and includes a controller 51 (see FIG. 6 ) having a CPU, a ROM, a RAM and the like, a display section 52 and an input device 53 . In addition, the display section 52 is provided in order to display the analysis result obtained by analyzing data of digital signals transmitted from the first measuring unit 2 and the second measuring unit 3 .
In addition, as shown in FIG. 6 , the control apparatus 5 is composed of a computer 500 mainly including the controller 51 , the display section 52 and the input device 53 . The controller 51 mainly includes a CPU 51 a , a ROM 51 b , a RAM 51 c , a hard disk 51 d , a reading device 51 e , an I/O interface 51 f , a communication interface 51 g and an image output interface 51 h . The CPU 51 a , ROM 51 b , RAM 51 c , hard disk 51 d , reading device 51 e , I/O interface 51 f , communication interface 51 g and image output interface 51 h are connected by a bus 51 i.
The CPU 51 a can execute computer programs stored in the ROM 51 b and computer programs loaded to the RAM 51 c . When the CPU 51 a executes application programs 54 a , 54 b and 54 c to be described later, the computer 500 functions as the control apparatus 5 .
The ROM 51 b is composed of a mask ROM, a PROM, an EPROM, an EEPROM or the like, and computer programs which are executed by the CPU 51 a and data which are used in the execution of the programs are recorded therein.
The RAM 51 c is composed of a SRAM, a DRAM or the like. The RAM 51 c is used to read computer programs which are recorded in the ROM 51 b and the hard disk 51 d . In addition, the RAM is used as a work area of the CPU 51 a when these computer programs are executed.
In the hard disk 51 d , various computer programs for execution by the CPU 51 a , such as an operating system and an application program, and data which are used to execute the computer programs, are installed. A measurement process ( 1 ) program 54 a for the first measuring unit 2 , a measurement process ( 2 ) program 54 b for the second measuring unit 3 and a sampler operation processing program 54 c for the specimen transport apparatus 4 are also installed in this hard disk 51 d . By executing these application programs 54 a to 54 c with the CPU 51 a , the operations of sections in the first measuring unit 2 , second measuring unit 3 and specimen transport apparatus 4 are controlled. A measurement result database 54 d is also installed in the hard disk 51 d.
The reading device 51 e is composed of a flexible disk drive, a CD-ROM drive, a DVD-ROM drive or the like and can read computer programs or data which are recorded in a portable recording medium 54 . In addition, the application programs 54 a to 54 c are stored in the portable recording medium 54 and the computer 500 can read the application programs 54 a to 54 c from the portable recording medium 54 and install the application programs 54 a to 54 c in the hard disk 51 d.
The above-described application programs 54 a to 54 c are provided by the portable recording medium 54 and can be also provided from an external device, which is connected to the computer 500 by an electric communication line (which may be wired or wireless) to communicate therewith, through the electric communication line. For example, the application programs 54 a to 54 c are stored in the hard disk of a server computer on the internet and the computer 500 accesses the server computer to download the application programs 54 a to 54 c and to install the programs in the hard disk 51 d.
Further, in the hard disk 51 d , for example, an operating system for providing a graphical user interface environment, such as Windows (registered trade name) which is made and distributed by Microsoft Corporation in America, is installed. In the following description, the application programs 54 a to 54 c operate on the above-described operating system.
The I/O interface 51 f is composed of, for example, a serial interface such as USB, IEEE1394 or RS-232C, a parallel interface such as SCSI, IDE or IEEE1284, and an analog interface including a D/A converter and an A/D converter. The input device 53 is connected to the I/O interface 51 f and a user uses the input device 53 so as to input data to the computer 500 .
For example, the communication interface 51 g is an Ethernet (registered trade name) interface. By the communication interface 51 g , the computer 500 can transmit and receive data to and from the first measuring unit 2 , second measuring unit 3 , specimen transport apparatus 4 and host computer 6 by using a predetermined communication protocol.
The image output interface 51 h is connected to the display section 52 composed of an LCD or a CRT so as to output to the display section 52 a picture signal corresponding to image data provided from the CPU 51 a . The display section 52 is configured to display an image (screen) in accordance with an input picture signal.
Due to the above-described configuration, the controller 51 is configured to analyze the components of an analysis target by using the measurement result transmitted from the first measuring unit 2 and the second measuring unit 3 and to obtain the analysis result (the number of red blood cells, the number of platelets, the amount of hemoglobin, the number of white blood cells and the like).
[Blood Sample Processing Method]
Next, an embodiment of a blood sample processing method of the present invention, which uses the above-described blood sample processing apparatus 1 , will be described focusing on a characteristic inclining-stirring operation by using FIGS. 13 and 14 . Since the first measuring unit 2 and the second measuring unit 3 perform the analysis including stirring and aspiration of a specimen with the same operation, a blood sample processing method of the first measuring unit 2 will be described hereinafter and a blood sample processing method of the second measuring unit 3 will be omitted.
First, a user sets a rack 110 , in which a specimen container 101 with a lid storing a blood sample as an analysis target is installed, on the specimen transport apparatus 4 . Next, when determining that an analysis start instruction is issued by the pressing of the start button (Step S 1 ), the CPU 51 a of the control apparatus 5 controls the transport of the rack 110 by the specimen transport apparatus 4 to position the above-described specimen container 101 at the first ejection position (specimen container ejection position) 43 a (Step S 2 ).
The CPU 51 a ejects the specimen container 101 from the rack 110 by using the hand section 251 (Step S 3 ). In greater detail, the CPU 51 a drives the vertical moving section 253 such that the hand section 251 in an opened state moves down from the upper side and is stopped at a specimen container holding position where the specimen container 101 can be held.
Next, the CPU 51 a drives the opening-closing section 252 to close the hand section 251 and thus the specimen container 101 is held. In addition, the CPU 51 a drives the vertical moving section 253 again such that the hand section 251 is lifted in a state of holding the specimen container 101 , and the specimen container 101 is ejected from the rack 110 and stopped at a predetermined position. In this state, the specimen container 101 is in an upright state such that the axis thereof in a longitudinal direction is substantially in the vertical direction.
<Stirring Process>
Next, the CPU 51 a performs an inclining-stirring operation of the specimen container 101 by driving the stirring motor section 254 (step S 4 ). The flow of this stirring operation will be described later by using FIG. 14 . In this stirring process, the hand section 251 holding the specimen container 101 rotates forward and backward to stir the blood sample stored in the specimen container 101 . FIG. 10 is a diagram showing the inclining-stirring operation of the specimen container 101 by the hand section 251 , and shows both of an aspect in which the specimen container 101 is held in an upright state by the hand section 251 and an aspect in which the specimen container 101 is held in an inclining state by the hand section 251 . As shown in FIG. 10 , the hand section 251 performs the inclining-stirring operation which includes a first rotation process of rotating the hand section to reach an inclining state in which the bottom portion of the specimen container 101 is positioned higher than the sealing lid 102 of the specimen container 101 and a second rotation process of inversely rotating the hand section to return the specimen container 101 to an upright state from the inclining state.
In the above-described inclining state, an angle θ which is formed between a vertical line V and an axis L in the longitudinal direction of the specimen container 101 is about 127 degrees (see FIG. 10 ).
The hand section 251 repeatedly performs an inclining-stirring operation, in which the first rotation process and the second rotation process are set as one cycle, ten times. In addition, the second rotation process at the final cycle is carried out for 0.8 seconds or longer (in this embodiment, about 1.87 seconds). In this embodiment, the first rotation processes and the second rotation processes other than the second rotation process at the final cycle are performed for a shorter time than the second rotation process at the final cycle, for example, for about 0.4 to 0.6 seconds (in this embodiment, about 0.43 seconds). In this manner, by performing the second rotation processes other than the second rotation process at the final cycle for a shorter time than the second rotation process at the final cycle, the time required for all of the multiple inclining-stirring operations can be reduced.
Due to the above-described inclining-stirring operations, the blood sample adheres to the back side of the sealing lid 102 of the specimen container 101 . However, by slowly performing the dropping process at the final cycle for 0.8 seconds or longer, the blood sample adhering to the back side of the sealing lid 102 of the specimen container 101 can be moved to the bottom portion of the container. The principle whereby the blood sample adhered to the back side of the sealing lid 102 runs down into the container can be assumed and confirmed as follows.
FIG. 7 is a perspective view of the sealing lid 102 viewed from the upper side, FIG. 8 is a perspective view of the same sealing lid viewed from the lower side, and FIG. 9 is a longitudinal sectional view of the sealing lid 102 shown in FIGS. 7 and 8 . The sealing lid 102 is made of a synthetic resin such as silicon rubber having elasticity and has a lid main body 103 which is inserted into the opening of a specimen container 101 . In the lower surface of the lid main body 103 , a concave portion or recess 104 is formed and a brim section 105 is formed at the upper end portion of the circumferential surface of the lid main body 103 . A concave portion or recess 106 is also formed in the upper surface of the lid main body 103 and a piercer 211 pierces a bottom surface 106 a of the concave portion 106 .
When the inclining-stirring operation is applied to the specimen container 101 sealed by the sealing lid 102 having the above-described configuration, the blood sample moving to the inside of the concave portion 104 of the sealing lid 102 in an inclining state adheres to a back surface 102 a of the sealing lid 102 and an inner circumferential surface 103 a of the lid main body 103 in a spherical shape by the action of surface tension on the interface of the blood sample (see FIG. 11A ).
When the specimen container 101 is slowly returned to the upright state from the inclining state for 0.8 seconds or longer, as shown in FIG. 11B , a time at which the specimen container 101 is tilted in a state in which the sealing lid 102 is positioned higher than the bottom portion of the specimen container 101 is increased. When the specimen container 101 is tilted in a state in which the sealing lid 102 is positioned higher than the bottom portion of the specimen container 101 , the surface area of the blood sample is increased, the spherical shape collapses, and as a result, surface tension is decreased. That is, the pressure in the blood sample is decreased and a force pulling the molecules of the surface of the blood sample to the inside is decreased. In this manner, it is thought that a force causing the blood sample to remain on the back side of the sealing lid 102 is decreased, the blood sample runs down to the bottom portion of the specimen container 101 due to the influence of gravity, and as a result, the amount of blood sample adhering to and remaining on the back side of the sealing lid 102 can be significantly decreased (see FIG. 11C ).
Table 1 shows results which are obtained by surveying a blood leakage state (whether or not the blood is leaked from the groove in the longitudinal direction formed in the outer circumferential surface of the piercer when the piercer penetrates the lid after stirring) when a time required for the second rotation process at the final cycle is variously changed in the case in which a 10-cycle inclining-stirring operation is performed. As the sealing lid, a lid of the type shown in FIGS. 7 to 9 is used and the amount of blood stored in the specimen container is 4 ml.
The inclining-stirring operation is performed by using a pulse motor and set pulse values in the second rotation process at the final cycle are set as a low-speed value and a high-speed value shown in Table 1. In greater detail, the “set pulse value” is the number of driving pulses (pulse speed) which are applied to the pulse motor per second. In this inclining-stirring operation, the pulse motor is driven such that the pulse speed increases from the set pulse value shown by a low-speed value to the set pulse value shown by a high-speed value, and after the elapse of a predetermined time, the pulse motor is driven such that the pulse speed decreases from the set pulse value shown by a high-speed value to the set pulse value shown by a low-speed value. Accordingly, the hand section is set so as to rotate at a low speed for a predetermined time after the start of the rotation and a predetermined time before the end of the rotation and to rotate at a high speed for the remaining time. In other words, when the horizontal axis represents time and the vertical axis represents pulse speed, the pulse value is changed such that the pulse speed changes in a trapezoidal shape. The “processing time” in Table 1 is a time required for the second rotation process at the final cycle, and in the test shown in Table 1, the second rotation processes other than the second rotation process at the final cycle and the first rotation processes are performed for 0.43 seconds, respectively.
TABLE 1
Returning Operation
The Number of Specimen
of Final Stirring
Containers Without Leakage
Set Pulse Value
(Amount of Blood 4 mL)
Processing
Stirring
[Low
[High
Among 10
Among 100
Time
No.
Condition
Speed]
Speed]
Containers
Containers
[s]
1
Ten-time Stirring
100
600
0
—
0.43
2
* Returning
100
300
9
—
0.72
3
Operation of Final
100
200
10
—
0.94
4
Stirring is Slowly
75
150
10
90
1.25
5
Performed
60
120
10
99
1.56
6
50
100
10
100
1.87
As can be seen from Table 1, when all the second rotation processes and the first rotation processes in the 10-cycle inclining-stirring operation are performed for 0.43 seconds, respectively (Test No. 1), leakage of the blood is observed in all of the ten specimen containers. However, when the second rotation process at the final cycle is performed for 0.94 seconds, which is longer than 0.8 seconds (Test No. 3), leakage of the blood is not observed in any of the ten specimen containers. In addition, when the second rotation process at the final cycle is performed for 1.56 seconds, which is longer than 1.4 seconds (Test No. 5), leakage of the blood is not observed in any of the ten specimen containers, and even when the number of specimen containers is increased to 100, leakage of the blood is observed in only one specimen container.
Accordingly, it was found that the amount of blood sample adhering to and remaining on the back side of the lid can be significantly decreased by setting a time required for the second rotation process at the final cycle to 0.8 seconds or longer and it was found that the amount of blood sample adhering to and remaining on the back side of the lid can be more significantly decreased by setting the above-described time to 1.4 seconds or longer.
Next, the flow of the inclining-stirring operation of the specimen container 101 will be described by using FIG. 14 . In the following description, a rotation process of shifting a specimen container 101 in an upright state into an inclining state is referred to as “first rotation process” and a rotation process of returning a specimen container 101 in an inclining state to an upright state is referred to as “second rotation process”, and particularly, the second rotation process which returns a specimen container 101 in an inclining state to an upright state in the final cycle is referred to as “second low-speed rotation process”.
First, the CPU 51 a performs the first rotation process of rotating a specimen container 101 from an upright state to an inclining state (Step S 41 ), and then performs the second rotation process of returning the specimen container 101 to an upright state from an inclining state (Step S 42 ). The respective first and second rotation processes are performed for 0.43 seconds. Next, the CPU 51 a determines whether or not the number of inclining-stirring operations in which the first rotation process and the second rotation process are set as one cycle reaches 9 (Step S 43 ), and when the number of inclining-stirring operations does not reach 9, the CPU 51 a repeatedly performs the operations of Steps S 41 and S 42 .
When the number of the inclining-stirring operations reaches 9, the CPU 51 a performs the first rotation process once again (Step S 44 ), and then performs the second low-speed rotation process (Step S 45 ). Then, the process returns to the blood sample processing. In the second low-speed rotation process in Step S 45 , an operation of returning the specimen container 101 in an inclining state to an upright state is performed for a longer time than other processes, that is, 1.87 seconds.
During the stirring operation of the specimen container 101 , the rack 110 is evacuated from the specimen container ejection position 43 a and the specimen setting section 255 a moves forward up to a predetermined position positioned below the hand section 251 due to the driving of the specimen container transport section 255 . After the stirring, the CPU 51 a moves the hand section 251 down and opens the hand section 251 , and thus the specimen container 101 held in the hand section 251 is set in the specimen setting section 255 a (Step S 5 ).
Next, the hand section 251 is lifted, and the specimen setting section 255 a is drawn into the apparatus by the driving of the specimen container transport section 255 and positioned at a predetermined position.
<Aspiration Process>
Next, the CPU 51 a performs an operation of aspirating the specimen from the specimen container 101 (Step S 6 ). In greater detail, in a state in which the specimen container 101 is held by the chuck section 27 so as not to move due to the control of the CPU 51 a , the piercer 211 is driven by the piercer moving section 212 and moves down from the upper side to penetrate the sealing lid 102 of the specimen container 101 , and is stopped at a predetermined position. In this penetration operation, as described above, the blood sample adhering to the back side of the lid 102 moves to the bottom portion of the container during the inclining-stirring operation and thus does not remain on the back side of the lid 102 . Accordingly, there is no leakage to the outside from the groove 211 a in the outer circumferential surface of the piercer 211 for opening to the atmosphere.
After the piercer 211 is stopped at the predetermined position in the specimen container 101 , a predetermined amount of the blood sample is aspirated by the piercer 211 . After the aspiration, the piercer 211 is lifted and the aspirated blood sample is mixed with a reagent in a reaction container of the sample preparation section 22 , and thus a sample for measurement is prepared. Then, the prepared sample for measurement is transferred to the detecting section 23 and predetermined items are detected (measured) in the detecting section 23 . The detection result is transmitted to the controller 51 and the components of the analysis target are analyzed in the controller 51 . The obtained analysis result is displayed on the display section 52 .
After the piercer 211 is lifted, the CPU 51 a performs an operation for returning the specimen container 101 to the original rack 110 (Step S 7 ). In greater detail, due to the control of the CPU 51 a , the specimen setting section 255 a is moved forward once again by the driving of the specimen container transport section 255 and is stopped at the specimen container setting position. Next, the hand section 251 moves down from the upper side and is stopped at the specimen container holding position.
Next, the hand section 251 is closed to hold the specimen container 101 of the specimen setting section 255 a , and after that, the hand section 251 is lifted and stopped at a predetermined position. During the lifting of the hand section 251 holding the specimen container 101 , the specimen setting section 255 a is drawn into the apparatus by the driving of the specimen container transport section 255 . In addition, the evacuated rack 110 advances and is stopped at a predetermined position.
Next, the hand section 251 moves down and inserts the specimen container 101 into the rack 110 . Then, the hand section 251 is opened by the opening driving of the opening-closing section 252 and thus the specimen container 101 is set in the rack 110 . Then, the hand section 251 is lifted. After that, the CPU 51 a determines whether or not there is a specimen container storing a blood sample to be analyzed next (Step S 8 ). When there is a next specimen container, the process proceeds to Step S 2 and the rack 110 is moved to position a specimen container 101 storing a blood sample to be analyzed next at the specimen container ejection position. The above-described sequence of operations starting from the dropping of the opened hand section 251 is repeatedly performed in the same manner. In Step S 8 , when it is determined that there are no specimen containers storing a blood sample to be analyzed next, the CPU 51 a completes the process.
As described above, in this embodiment, since the inclining-stirring operation of a specimen container is repeatedly performed and the second rotation process of the final inclining-stirring operation is performed for a longer time (0.8 seconds or longer) than in other second rotation processes, the blood sample adhering to the back side of the lid of the specimen container can be moved to the bottom portion of the specimen container. Accordingly, at the time point when the inclining-stirring operation is completed, a state in which the blood sample adheres to the back side of the lid of the specimen container can be resolved or suppressed. For example, the leakage of the blood sample in the specimen container out of the container when a piercer penetrates the lid can be resolved or suppressed.
In addition, since a state in which the blood sample adheres to the back side of the lid of the specimen container can be resolved or suppressed, wastage of a portion of the blood sample collected from a patient can be suppressed.
In the above-described blood sample processing method, the second rotation process which is performed just before the piercing of the piercer is slowly carried out for 0.8 seconds or longer and the time required for other second rotation processes and first rotation processes is not particularly limited. However, from the point of view of decreasing the total processing time, it is preferable that other second rotation processes and first rotation processes are performed for a shorter time than the second rotation process which is performed just before the piercing of the piercer.
In the above-described embodiments, the inclining-stirring operation is an operation reciprocating from an upright state to an inclining state with an angle of about 127 degrees between the vertical line and the axis of the specimen container. However, as long as the inclining state exists in which the bottom portion of the specimen container is positioned higher than or as high as the lid, the inclining-stirring operation is not limited to the exemplified operation and various inclining-stirring operations can be performed. For example, the above-described angle θ may be smaller than or larger than 127 degrees. For example, the angle θ may be 180 degrees or may be 90 degrees. In addition, the hand section 251 may not only be rotated in a space in one direction viewed from the vertical line V as in this embodiment, but may also be rotated in a space in another direction viewed from the vertical line V in addition to the above-described space.
In the above-described embodiments, a specimen container 101 in an upright state is rotated in one direction to be shifted into an inclining state, and then the specimen container 101 is inversely rotated to return to the original upright state. However, the present invention is not limited thereto. For example, the specimen container 101 in an upright state may be rotated in one direction to be shifted into an inclining state and may be further rotated in the one direction to return to the original upright state from the inclining state.
In the above-described embodiments, a specimen container 101 is stirred by repeating an operation in which the specimen container 101 in an upright state is shifted into an inclining state and is stopped once and then the specimen container 101 is returned to the original upright state. However, the present invention is not limited thereto. For example, an operation may be continuously repeated in which the specimen container 101 in an upright state is rotated to be shifted into an inclining state and then is rotated by 360 degrees as it is without stopping the specimen container 101 so as to be returned to the original upright state. In the case of this stirring operation, a process of returning the specimen container in an inclining state to an upright state at the final cycle is performed at a lower speed than other processes, and thus the amount of blood sample adhering to and remaining on the back side of the lid of the specimen container 101 can be decreased.
In the above-described embodiments, the aspiration tube carries out the opening to the atmosphere and moves to a predetermined aspiration position with one dropping operation. However, the present invention is not limited thereto. Another aspiration tube may be used such as an aspiration tube of a two-time-piercing type which only carries out opening to the atmosphere with an initial dropping operation and moves to a predetermined aspiration position after rising once and dropping again.
In the above-described embodiments, a blood cell counting apparatus is used as the blood sample processing apparatus. However, a smear preparation apparatus may be used as the blood sample processing apparatus.
In the above-described embodiments, the second rotation process which is performed just before the piercing of the piercer is performed for a shorter time than in other processes. However, all the processes may be performed for the same time period as in the second rotation process which is performed just before the piercing of the piercer.
In the above-described embodiments, a 10-cycle inclining-stirring operation is performed. However, inclining-stirring operations having various numbers of cycles may be performed, and for example, an 8-cycle inclining-stirring operation may be performed. | A blood sample processing apparatus including: a container holder securing a sample container that contains a blood sample, the sample container having a lid, the container holder coupled to a rotation driver that longitudinally rotates the sample container; and a controller that commands the rotation driver to repeatedly perform an inclining-stirring operation that includes a first process and a second process, wherein in the first process, the sample container is initially held in an upright position by the container holder and then rotated to an inclined position, and in the second process, the inclined sample container is returned to the upright position, and wherein in a final inclining-stirring operation, the second process is carried out for a longer time than previous second processes. | 6 |
U.S. GOVERNMENT RIGHTS
This invention was developed under Dept. of Air Force Contract No. F33615-90-C-2076 and the U.S. Government has certain rights hereto.
BACKGROUND OF THE INVENTION
The requirements for onboard strategic and tactical missile power systems are complex. The most significant requirements are ultra-high energy density, the capability of operating between about -50° and about +75° C., initiation without an external heat source with about 1 second or less delay from initiation to full load, and a shelf life of at least about 25 years.
Among the pulse batteries under development, the current state-of-the-art lithium systems have become very attractive, because of their energy density. Several types of batteries appear to be of practical interest. Recent years have seen a fast pace in the research and development of promising pulse batteries. Lithium-thionyl chloride batteries designated as RLI/SOCL 2 are presently used as a power source for missile and other military weapon applications. The theoretical energy density of an Li/SOCl 2 battery is 1600 WH/Kg; with a theoretical cell voltage of 3.1 volts.
Watanabe, N. T., T. Nakajima, and H. Touhara, Graphite Fluorides, Elsevier (1988) discloses a Li/(CF) power system. Its energy density is, however, much too low for on-board power for missile operations. H 2 /O 2 fuel cells and H 2 /Br 2 fuel cells are not yet fully developed and also appear to exhibit too low an energy density.
An object of the present invention is to develop a battery that is capable of meeting the specific energy requirements for use generating strategic and tactical onboard power for missile and other high energy density applications.
Another object of the invention is to produce a power source that has a substantially indefinite shelf life, yet is capable of a quick start-up under a variety of conditions.
DISCLOSURE OF THE INVENTION
Accordingly, the present invention is directed to a power generating system, particularly a fuel cell system, comprising a source of hydrogen and a source of fluorine and means for utilizing the sources of fluorine and hydrogen to produce power. Generally, the means for utilizing the sources of hydrogen and fluorine comprises an electrode assembly and a current collector for collecting power generated during the operation of the system. The electrode assembly comprises a hydrogen anode and a fluorine cathode with an electrolyte disposed between the two electrodes. The electrolyte composition is selected such that it is solid and porous until activated during operation of the device. The preferred electrolyte is KF.xHF impregnated into a separator layer of a matrix material.
Hydrogen and fluorine are stored separately. They are introduced into the device and combine in the pores of the KF.xHF electrolyte matrix. The hydrogen and fluorine react, with or without a catalyst, to form HF which increases the HF concentration in the electrolyte, lowers the melting point of the KF.xHF electrolyte, and yield heat (reaction exothermic) to produce a molten electrolyte. The hydrogen/fluorine system begins operating once the electrolyte is molten. Fluorine is electroreduced at the cathode to fluoride ions which travel across the electrolyte and react with hydrogen to produce hydrogen fluoride which flows out of the anode cavity with some excess hydrogen, which is either vented to the atmosphere or absorbed with, a suitable material such as NaF.
The power producing system of the present invention has an extremely high energy density which is over twice the energy density of a Li/SOCl 2 fuel cell and produces 2 volts of power. The triple reserve nature of the device translates to a power system with a relatively long shelf life of greater than 25 years. The power producing system may be activated at any temperature down to about -188° C. (the liquidus temperature of fluorine) and operates at any temperature in the range in which the electrolyte remains molten (i.e. about -10° to about 250° C., depending on the value of x in KF.xHF. The start-up time of the fuel cell is very fast in comparison to thermal and/or reserve batteries, generally less than about 1 second. The power producing system of the present invention is particularly useful in tactical missile power, military space power and portable weapon systems.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a sectional view of a power generating system according to the present invention.
FIG. 2 is a perspective view of the power generating system of FIG. 1.
FIGS. 3-9 are graphs showing the test results of the fuel cell power generating systems of Examples 3-7.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to the drawings, the power generating system according to the present invention will now be described with reference to a fuel cell which is shown in FIGS. 1 and 2. As shown the fuel cell 10 comprises current collector plates 12 and 14 having gas plenums 13 and 15 and gas inlets 16 and 18. Disposed between the collector plates 12 and 14 is an electrode assembly 20 which is shown in a perspective view in FIG. 2. The electrode assembly 20 comprises a fluorine cathode 22, a hydrogen anode 24 and an electrolyte separator 26 disposed between the cathode and anode. Cathode and anode gaskets 28 and 30, respectively, in combination with face gasket 29 physically and electrically isolate the anode and cathode chambers within the current collector plates 14 and seal the cell. Face gasket 29 particularly serves to seal the anode and cathode electrodes. The source of fluorine gas is shown at 32 and the source of hydrogen gas is shown at 34. The supply of the fluorine and hydrogen gases is regulated by means of control valves 36 and 38 which may be controlled by suitable and conventional means.
The current collector plates 12 and 14 must be made out of electrically conductive and chemically resistant materials. The plates must be chemically resistant to fluorine and hydrofluoric acid. Suitable materials include Fe, steel, Ni, Al, monel, Cu, Mg alloys, and Ag. Aluminum and copper are presently the more preferred materials, with copper being the most preferred. The current collector plates are machined from blanks of metal. Plate 12 is machined to have an anode chamber and plate 14 is machined to have a cathode chamber.
The electrode materials that are employed may be any of those used in the electrolysis of HF to produce fluorine. Thus, the anode generaly comprises an electrocatalytic metal such as platinum, silver, steel or nickel, disposed on a suitable substrate. Platinum is presently the most preferred metal. The metals are generally dispersed in amounts of about 10 to 20 wt % upon carbon particles. The cathode comprises an electrocatalyst such as non-graphitized carbon powder such as Vulcan XC-72, BlackPearl 2000, or derivatives thereof on a suitable substrate. Suitable substrates include carbon fiber paper, nickel exmet (nickel expanded metal), graphite cloth, graphite felt, woven wire cloth, porous polymers, woven polytetrafluoroethylene cloth, and the like. The electrocatalyst is preferably added to a conventional binder such as polytetrafluoroethylene (PTFE) or fluorinated ethylene-propylene polymers (FEP) which form porous gas diffusion layers which are then bonded to the substrate.
The electrodes contain electrocatalyst in an amount of from about 5 to 10 mg/cm 2 , more preferably in an amount of from about 2 to 5 mg/cm 2 . The amount of electrocatalyst may be larger or smaller than the above ranges if desired and depending upon the particular electrocatalyst and substrate employed. Selection of suitable amounts of electrocatalyst for a particular operation is within the skill of the art.
While any conventional electrode fabrication process may be employed, a particularly preferred process is set forth hereinafter. To accomplish electrode fabrication, a slurry of electrocatalyst is sonicated and stirred while the appropriate quantity of a polytetrafluorethylene (PTFE) suspension, generally containing PTFE, water, and a suitable emulsification agent, is added. The pH of the solution is adjusted, generally to about 3 to 3.5, while stirring to promote flocculation and electrocatalyst/PTFE agglomeration. The solution is then allowed to sit undisturbed until flocculation is verified. Flocculation is verified by the segregation of the solution into two layers, a catalyst-PTFE slurry and a clear supernatant, and is caused by the binding of PTFE to the carbon particles upon which the catalytic metals had been deposited. The resulting slurry is stirred and cast onto glazed paper, which is conventionally used in electrode manufacture, by vacuum filtration. The PTFE-bonded catalyst layer is then transferred from the paper to an electrode substrate, such as wetproofed carbon fiber paper (e.g. Stackpole Co. type PC-206 or TORAY), by rolling, pressing, and heating. Wetproofed carbon fiber paper is generally prepared by immersion of carbon paper into a fluorocarbon suspension, followed by drying and sintering of the paper. The electrode is then dried and sintered. Sintering refers to the change that the PTFE undergoes when heated to its softening temperature: the PTFE flows over the supported catalyst to form the hydrophobic gas diffusion structure. The electrode is now ready for use.
The electrolyte comprises a salt having the formula KF.xHF wherein x at least about 1, preferably about 2 to about 8, most preferably from about 2 to about 5. When X is about 2 or more the melting point of the salt will be greater than the upper limit of the expected ambient temperature range of HF. The KF.xHF salt is impregnated into a porous inert and electronically insulating separator layer composed of a matrix material to form the electrolyte layer, which is disposed between the anode and cathode. The separator may be formed from any suitable material such as a PTFE woven fabric or any other material which is chemically inert to the system, electronically non-conductive, and also wet easily in the electrolyte. A porous PTFE cloth such as a polytetrafluoroethylen fabric sold by Stern & Stern Textiles is presently the most preferred material. The electrolyte layer is prepared by crystallizing the appropriate electrolyte salt from a melt onto the separator material under an inert dry atmosphere. The electrolyte is preferably applied to both sides of the separator. The thin electrolyte layer may also be on a catalyst layer or electrode to aid the reaction of the H 2 and F 2 gases. Suitable catalysts include a platinum electrode for H 2 and a carbon electrode for F 2 . The catalysts are preferably present in amounts of from about 5 to 10 mg/cm 2 .
In an operating cell, the electrolyte will be formed by either the reaction of KF.xHF with HF (after the HF is formed by the reaction of H 2 and F2, liberating heat) or by the use of KF.x2HF initially which will melt when HF is produced. The quantity of H 2 and F 2 required to produce the heat required can be introduced upon initiation so that the cell comes to full load as rapidly as possible. The cell reactions are fluorine reduction at the cathode and H 2 oxidation and HF formation at the anode. The current carrying species contains fluoride, possibly HF The HF produced will in part be dissolved in the electrolyte.
The gaskets, which physically and electrically isolate the anode and cathode chambers and seal the cell, are made from any suitable material which accomplishes this isolation. Presently, the preferred material is PTFE. The gaskets are hot pressed and then cut to size. The thickness of the gaskets will depend upon the thicknesses of the electrolyte layer, the anode and cathode.
The remaining components of the system include pressurized storage containers for the hydrogen 36 and fluorine 38 gases. The containers may be made from any suitable materials which are normally used in pressurized applications. The introduction of the gases to the fuel cell 10 is regulated by control valves 34 and 36, which are preferably solenoid valves. Suitable flow meters (not shown) and pressure regulators (not shown) may also be used. An electrolyte reservoir (not shown), e.g. a small cavity outside of the pegs or grooves of the current collector plates through which molten electrolyte may flow via capillary action into the electrode assembly. All surfaces in contact with F 2 gas, including the container 38, valve 34 and connecting piping, must be thoroughly cleaned, dried and passivated.
In operation, hydrogen and fluorine gases from container 36 and 38, respectively, are fed to the fuel cell 10. Hydrogen and fluorine combine in the pores of the electrolyte layer. Preferably, with the aid of a catalyst contained in the electrolyte layer, H 2 and F 2 react to form HF. The reaction that takes place is exothermic and the heat released from the reaction melts the KF.xHF electrolyte layer thereby generating molten electrolyte. Alternatively, the molten electrolyte is formed by the reaction of KF.HF with HF, which is first formed by the reaction of H 2 and F 2 . No matter which mode of electrolyte formation occurs, the HF formed during this process may combine with the electrolyte which still remains molten. The fuel cell begins to operate as soon as the electrolyte becomes molten. Fluorine is electroreduced at the cathode to fluoride ions which are transported across the electrolyte and react with hydrogen at the anode to produce HF and power. The HF which flows out of the anode cavity in the collector plate 14 with some excess hydrogen is either vented to the atmosphere or absorbed, for example, with NaF.
The reaction at the cathode is:
F.sub.2 +2e-→2F-
The reaction at the anode is:
H.sub.2 +2F-→2HF+2e-
The net reaction therefor is:
H.sub.2 +F.sub.2 →2Hf.
The standard electrode potential for this reaction is 2,876 volts. The theoretical maximum energy density of the H 2 /F 2 power device of the present invention is 3730 Wh/kg as compared to the 1600 Wh/kg maximum energy density of a Li/SOCl2 device.
One possible design for a fuel cell system according to the present invention is set forth hereinafter. Table 1 shows the results of a design for a 2.2 kW system running for 1 hr. The weight of the fuel cell is 10 kg having an output voltage of 24 volts with operating current density of 10,000 mA/cm 2 . The expected single cell voltage is 2.5 V. The area of the cell stack is determined from the current and power densities plus an allowance for 1 cm of edge seal on all sides.
The thickness of the stack is based on the number of cells and a thickness per unit cell based on similar designs for H 2 /O 2 fuel cells with an allowance for the additional thickness of the endplates. The weight and volume of the stack calculated based on these dimensions, the density of the cell blocks (using copper), and an assumed void volume (40%). The weight of reactants is determined by faradaic relationship. Thus, of the 10 kg allowed for this system, the cell stack and reactants weigh only 1.2 kg. Light weight aluminum storage tanks for high pressure fluorine and reinforced plastic tanks for hydrogen (as used for space shuttle applications) provide a weight for the complete system of less than 10 kg.
TABLE I______________________________________Design for 2.2 kW System Operating for 1 hour(Permissible Weight 10 Kg)______________________________________System Voltage 24 VoltsSystem Power 2200 WattsSingle Cell 2.5 VoltsCurrent Density 10,000 mA/cm.sup.2Power Density 25 W/cm.sup.2Active Area No 88 cm.sup.2No. Cells 10Cell Stack Area 24.7 cm.sup.2Stack Thickness 3 cmStack Volume 74 cm.sup.3Stack Weight 311 gmF2 needed 16.4 moles/hr 624.0 gm/hrH2 needed 16.4 moles/hr 32.8 gm/hrTotal Energy 8,938 kJ/hrElectrical Energy 7,920 kJ/hrNet Heat Rejection 1,018 kJ/hr______________________________________
EXAMPLES
Each test cell as described in the following specific Examples comprises two machined current collector copper plates with gas chambers, fluid plenums, and fittings. The current collector plates are similar to the cell blocks used for other electrochemical cells, i.e.; a flat plate with the center machined with pegs or grooves to provide a gas chamber and with inlet/outlet ports using standard fittings. For this cell, an electrolyte reservoir was not required, which simplifies the design. The collector plates along with electrode assembly with PTFE gaskets are contained using insulated tie bolts. The electrodes used were porous PTFE-bonded gas diffusion type produced in accordance with standard procedures used for both phosphoric acid and alkaline fuel cell electrodes.
Prior to start up, the system was thoroughly cleaned, degreased, dried, and flushed with nitrogen, before the oxidant side of the process was passivated by exposure to F 2 . The cell was assembled with a cell package and placed on the test stand. The fuel and oxidant inlet and outlet lines were connected to anode and cathode fittings, respectively. Nitrogen was purged through the anode and cathode lines with cell at open circuit. The cell was heated to approximately 65°-70° C. using resistive heating pads mounted on the current collector plates. The plates had thermocouples for measuring cell temperature. After the cell had equilibrated and the electrolyte liquefied sealing the anode and cathode chambers, H 2 and F 2 were introduced at low flows, i.e. 50-60 cc/min for the hydrogen and 30-40 cc/min for the fluorine. The cell was allowed to stabilize at open circuit voltage. With reactants present, a resistive load was placed across the cell and power was drawn. In the cells of Examples 3, 4, 5, 6, and 7, after the cell was purged with N 2 , the H 2 and F 2 gases were started at room temperature. Once the open circuit voltage was stabilized, the cell was put on load at 500 mV potential. The cells were run for 2-3 hours and cell performance was measured at different temperatures. A computer-interfaced data acquisition and control system was used for controlling the cell current. The system monitored and recorded all cell operating parameters, e.g. current, voltage, temperature, etc.
The exhaust from the cell contained H 2 , HF, and some F 2 . The exhaust was scrubbed prior to venting using soda lime to remove F 2 and using NaF to remove HF.
After a test was completed, the system was flushed extensively with dry nitrogen prior to tearing down the cell for post-test examination.
In the Examples, Vulcan carbon powder is a non-platinized carbon powder available from Cabot, Corp; PC-206 carbon paper is a carbon fiber paper available from Stackpole Company, St. Mary's, Pa.; T216-38 Teflon Cloth is woven poly(tetrafluoroethylene) fabric screen available from Stern & Stern Textile, Inc. of Hornell, N.Y.; Toray carbon paper is a carbon paper prepared with polymer fibers and available from Toray Industries of Tokyo, Japan; T54-2G, T162-42, and T250-58 cloths are poly(tetrafluoroethylene) woven fabric screens available from Stern & Stern Textile, Inc. of Hornell, N.Y.
EXAMPLE
______________________________________Anode: 10 wt % Pt/Vulcan on PC206 carbon powderCathode: Vulcan on PC206 carbon paperElectrolyte: Anhydrous KF.2HFSeparator: T216-38 natural Teflon cloth, 9 mil thickGasket: 15 mil PTFE each on anode and cathode with 2 mil face gasket on each side thereof______________________________________
The cell package consisted of cathode gasket, cathode electrode, face gasket, separator soaked in molten KF.2HF electrolyte, face gasket, anode electrode, and anode gasket. The cell package was placed on the test stand. The cell bolts were coated with Teflon shrink tubing and Teflon washers were placerd on each side to avoid a short circuit between the anode and cathode plates. The bolts were tightened equally with a torque wrench. The cell was purged with N 2 and then heated to 70° C. by external heating pads attached to the copper plates. At a stable cell temperature, H 2 on the anode and 10% F 2 in N 2 on the cathode side were metered through the flow meters. The open circuit of the first cell was as high as 1.0 V, which was about one third less than the theoretical value. Despite the low open circuit, an effort was made to operate the cell on load. The 0.5 mA/cm 2 maximum current density was attained at 300 mV potential. The test was terminated, as there was no sign of performance improvements. The cell package showed pin holes on both sides of the electrodes due to overtightening of the cell bolts.
EXAMPLE
______________________________________Anode: 10 wt % Pt/Vulcan on TORAY carbon paperCathode: Vulcan on TORAY carbon paperElectrolyte: Anhydrous KF.2HFSeparator: T250-58 natural teflon cloth, 25 mil thickGasket: 20 mil PTFE each on anode and cathode with 2 mil face gasket on each side______________________________________
The cell package was put together in the same manner as described in Example 1. The cell was hot pressed at 80° C. in a Carver press at minimum pressure. The cell package was placed on the test stand and bolts were tightened to 30 lbs/in 2 . N 2 was purged through the anode and cathode side, then the cell was heated to 67° C. An open circuit of 1.63 volt was attained when H 2 and F 2 flowed through the anode and cathode side, respectively. The cell could not draw more than 3 mA current at 500 mV potential. On increasing the cell temperature to 75° C., the performance decay was drastic. The test was continued for about 2 hours and then terminated when the performance did not improve upon decreasing the cell temperature back to 67° C. The cell package showed 4 pin field impressions on the back side of the electrodes, but no pin holes. The compactness and tightness of the cell package indicated no crossover, i.e. no reactant leaks from the seal of the electrode assembly nor diffusion of reactant gases through the electrode.
Although the performance of the cells of Examples 1 and 2 was poor, they both did operate.
EXAMPLE
______________________________________Anode: 10 wt % Pt/Vulcan on TORAY carbon paperCathode: Vulcan on TORAY carbon paperElectrolyte: Anhydrous KF.2HFSeparator: T250-58 natural Teflon cloth, 25 mil thickGasket: 20 mil PTFE each on anode and cathode, and 2 mil face gasket on each side______________________________________
The cell package was prepared as described in Example 1, with the basic difference that the electrolyte was spread on both sides of the separator. The cell package was not hot pressed. The cell was placed on the test stand horizontally instead of vertically to avoid the dripping of molten electrolyte from the cell. The H 2 and F 2 flows were started at room temperature after the cell was purged with N 2 . When the open circuit was above 1.0 volt, the cell was operated on load. The current improved slowly from 0.2 mA to 6mA at 0.5 volt constant potential. The cell temperature also increased from 22° to 27° C. due to heat of reaction between H 2 and F 2 . The cell temperature was increased slowly to 70°-75° C. at a 0.5 volt constant potential. The results presented in FIGS. 3 and 4 show the polarization scan and temperature effect on the cell performance.
FIG. 3 shows the cell current at 0.5 V potential vs. temperature. The cell current increases steadily as the cell temperature increases up to the melting point of the electrolyte, approximately 65°-70° C. Above this temperature, a decrease in cell current is seen. This effect is a combination of electrolyte resistivity and electrokinetics.
The polarization scan at 71° C. cell temperature is shown in FIG. 4. The cell voltage dropped at higher current. This suggests that HF in the electrolyte evaporates faster than it is produced due to the reaction of H 2 and F 2 ions, resulting in solidification and higher resistivity of the electrolyte.
EXAMPLE
______________________________________Anode: 10 wt % Pt/Vulcan on PC206 carbon paperCathode: Vulcan on PC206 carbon paperElectrolyte: Anhydrous KF.2HFSeparator: T250-58 natural teflon cloth, 25 mil thickGasket: 20 mil PTFE each on anode and cathode, and 12 mil face gasket on each side______________________________________
The cell package was prepared similarly to the one described in Example 1. Electrolyte was spread on both sides of the separator. The complete cell package was hot pressed at 80° C. with 0 and 1000 lbs pressure for 5 minutes each. The test cell placed on the test stand horizontally instead of vertically to avoid the dripping of molten electrolyte from the cell. The H 2 and F 2 were started at room temperature after the cell was purged with N 2 . When the open circuit was above 1.5 volt, the cell was operated on load at 500 mV potential until the performance stabilized. The cell was heated using electrical heating pads. Polarization scans of the test cell were performed at various temperatures. The results presented in FIG. 5 show the polarization scan and temperature effect on the cell performance. The cell was cooled down and purged with nitrogen. The same cell was started again the next day, and the performance was monitored at various temperatures and current loads. The cell performance is better at the electrolyte melting temperature which is around 70° C. The fluorine ion conductivity is higher in the molten electrolyte, which reduces the internal resistance of the cell. The open circuit was higher (1.6-1.7 V) than in the cell of Example 3. The hot pressing of the cell package before the test improved the cell compactness and eliminated crossover. FIG. 5 shows that the H 2 /F 2 cell performance is reproducible and stable.
The post-test cell package showed no sign of pin holes. The impressions of the pin field on the back of the cathode indicates compactness of the cell package, which indicates that there was no crossover of gas flow during operation. A very small quantity of electrolyte remained on the separator.
EXAMPLE
______________________________________Anode: 10 wt % Pt/Vulcan on PC206 carbon paperCathode: Vulcan on PC206 carbon paperElectrolyte: Anhydrous KF.2HFSeparator: T162-42 white teflon cloth, 7 mil thickGasket: 15 mil PTFE each on anode and cathode with 2 mil face gasket on each side______________________________________
The cell package was hot pressed and placed horizontally on test stand. The only difference in this test cell than the previously described cells was the separator. A 7 mil T162-42 Teflon woven cloth was used instead of T250-58. The cell was tested with a cold pressed cell package. The polarization scan was taken at various cell temperatures. The open circuit at room temperature was about 1.1 Volt. The performance improved at higher cell temperatures, but not better than that of the cell of Example. The results are reported in FIG. 7. The specific cell resistance of the cell was about 4 ohms-cm 2 at 500 mV potential with 71° C. cell temperature, whereas the cell of Example 4 showed 0.5 ohms-cm at the same condition. The higher resistance could be due to the low permeability of the T162-42 separator. The permeabilities of the T162-42 and T250-58 separators are 7 and 1025 cfm, respectively. The results indicate that the separator should be as coarse as possible. Again, the results show that performance improves at higher cell temperatures.
EXAMPLE
______________________________________Anode: 10 wt % Pt/Vulcan on TORAY carbon paperCathode: Vulcan on TORAY carbon paperElectrolyte: Anhydrous KF.2HFSeparator: T54-42G white Teflon cloth, 7 mil thickGasket: 12 mil PTFE each on anode and cathode, and 2 mil face gasket on each side______________________________________
The electrolyte was spread on one side of separator and then cold pressed. The anode and cathode electrodes were wet with isopropanol and water in a 1:1 ratio. The electrolyte, KF.2HF dissolved in water, was spread on the electrodes and then the electrodes were allowed to dry. The cell package was prepared as usual, but without pressing, and then placed on the test stand horizontally. The separator, T54-42G, is a blend of 70% Teflon and 30% cotton, with a gas permeability of 881 cfm. The H 2 and F 2 were started at room temperature after purging the cell with N 2 . The open circuit at room temperature was 1.8 volt. The cell attained 60 mA current at 700 mV (iR corrected) potential at room temperature. Polarization scans were taken at three different cell temperatures: 25°, 35°, and 50° C.
The cell performance at 35° C. was 150-200 mV higher than the room temperature cell performance. The bolts were tightened during cell heating. The cell performance at 50° C. showed no further improvements than at 35° C. The post-test cell package showed pin holes due to over-tightening of the bolts.
The test results of the cell of Example 6 are presented in FIG. 8. This cell was built slightly differently than the cells of Examples 1-5 in that the anode and cathode electrodes were wetted with electrolyte before the cell package was assembled. At the start of the reactants, the open circuit at room temperature was 1.8 V, which was higher than the cells of Examples 1-5. The performance at 35° C. was 200 mV higher than at 25° C. The same trend did not follow at 50° C. because of pin holes in the cell package due to over-tightening of the cell bolts.
EXAMPLE
______________________________________Anode: 10 wt % Pt/Vulcan on PC206 carbon paperCathode: Vulcan on PC206 carbon paperElectrolyte: Anhydrous KF.2HFSeparator: T216-38 natural teflon cloth, 7 mil thickGasket: 12 mil PTFE each on anode and cathode, and 2 mil face gasket on each side______________________________________
The electrolyte was spread on one side of separator and then cold pressed at 20,000 lbs. The anode and cathode electrodes were wetted with isopropanol and water in a 1:1 ratio. The electrolyte, KF.2HF dissolved in water, was spread on the electrodes and then the electrodes were allowed to dry. The cell package was prepared as in the previous Examples but without pressing, and then placed on the test stand horizontally. The face gasket was cut with an 8 cm 2 circular opening instead of a 5×5 cm square cut to seal the electrode and electrolyte cell package. The electrodes and separator were cut to 6×6 cm square size. Upon introduction of H 2 and F 2 into the cell, the open circuit was 1.8 volts. The cell performance was allowed to stabilize at room temperature. The polarization scan data recorded at different temperatures, are presented in FIG. 9.
The electrode surface area was reduced to 8 cm 2 instead of 25 cm 2 . In most of the previous cells, it is believed the electrodes were not wetted completely with electrolyte. The current density of the cell calculated on the basis of 25 cm 2 active surface area may not be the true current density. During the electrode wetting procedure, it was observed that only part of the electrode area or just barely the upper most surface of the electrodes seemed to be wetted with electrolyte. The results of the cells of Examples 6 and 7 show that higher current could be attained only if the electrodes are properly wetted with electrolyte. | A H 2 /F 2 power generating system is disclosed. The system is particularly useful in producing power in military and space vehicle applications because of its high energy density and long shelf life. | 7 |
[0001] The present invention relates to chemoprotective compounds and method for producing chemoprotective compounds which may be incorporated into a variety of food products. More specifically, an extraction method is provided that is effective for providing an extract having a high ratio of chemoprotective compounds to less desirable compounds while providing a high yield of chemoprotective compounds. Enhanced yields and ratios of chemoprotective compounds are provided by an aqueous extraction method used in combination with adsorbents.
BACKGROUND
[0002] It is generally agreed that diet plays a large role in controlling the risk of developing cancers and that increased consumption of fruits and vegetables may reduce cancer incidences in humans. The presence of certain minor chemical components in plants may provide a major protection mechanism when delivered to mammalian cells.
[0003] Cruciferious vegetables contain phytochemical precursors to potent chemoprotectants especially glucoraphanin and its associated conversion product sulforaphane, that when delivered to mammalian cells trigger carcinogen detoxification mechanisms. In addition to reducing the risk of getting certain cancers, glucoraphanin through its bioactive conversion product sulforphane has recently been shown effective in destroying the organism responsible for causing the majority of stomach ulcers and may provide novel approaches for reducing the risk of developing cardiovascular and ocular diseases. Efforts are being undertaken to gain approval for making label claims on food products either naturally high in these agents or for foods containing added crucifer chemoprotectants. Products containing chemoprotectant additives, although without claims, are already on the market.
[0004] Cruciferous vegetables also contain other compounds, such as indole glucosinolates, which are problematic for maintaining good health. Not only are these compounds weak inducers of the carcinogen detoxification system, but also they can induce systems which may bioactivate certain pro-carcinogens. In addition, the breakdown products of indole glucosinolates formed in the stomach during digestion may act in a similar manner to dioxin, a very potent toxin. Therefore, it is advantageous to produce glucoraphanin-containing preparations containing as little residual indole glucosinolates, or other adverse compounds, as possible.
[0005] Several patents describe the development of highly chemoprotecant crucifer germplasm with a significantly improved ratio of glucoraphanin to indole glucosinolates (increasing the ratio from about 0.2 to ˜30). See, e.g., U.S. Pat. Nos. 6,521,818, 6,242,018, 6,177,122, 5,968,567, 5,968,505 and 5,725,895; however, developing the germplasm from laboratory to field trials to market will require considerable time, upwards of up to 5 years, and with no guarantee of success. Hence, there is a need to provide alternative methods for producing high yields of glucoraphanin with a high ratio of glucoraphanin to indole glucosinolates.
SUMMARY
[0006] The present invention is directed to chemoprotectant precursor compositions provided from crucifer seeds and sprouts and methods for their preparation. Treatment of aqueous extracts from crucifer seeds or sprouts with adsorbents substantially increases the ratio of certain highly chemoprotectant precursor compounds (alkyl glucosinolates such as glucoraphanin, a.k.a. sulforaphane glucosinolate) to undesirable compounds such as indole glucosinolates (for example 4-hydroxyglucobrassicin). The method provides an extract which has a ratio of glucoraphanin to 4-hydroxyglucobrassicin of about 70 or greater. The resulting extract has improved color and odor and may be dried or used directly as an additive in a variety of foodstuffs.
[0007] A method is provided for extracting chemoprotectants precursors from crucifer seeds or sprouts. Generally, the method includes forming an aqueous extract of crucifer seeds or sprouts. The aqueous extract is contacted with an adsorbent. The aqueous extract is separated from the adsorbent to provide a chemoprotectant enhanced extract. The method is effective for providing a chemoprotectant enhanced extract having a ratio of a number of alkyl glucosinolates, especially glucoraphanin to indole glucosinolates, specifically 4-hydroxyglucobrassicin of about 30 to about 1000 or greater, preferably about 100 to about 1000.
[0008] Crucifer vegetables have been identified as a good source of chemoprotectant precursor phytochemicals. Crucifer seeds and sprouts have been found to be an especially good source of chemoprotectant precursors. Crucifer seeds or sprouts which are especially useful include broccoli, kale, collard, curly kale, marrowstem kale, thousand head kale, Chinese kale, cauliflower, Portuguese kale, Brussels sprouts, kohlrabi, Jersey kale, savoy cabbage, collards, borecole, radish, and the like as well as mixtures thereof. In a very important aspect, crucifier seeds or seeds and sprouts of broccoli are utilized.
[0009] When crucifer seeds are used as a starting material, they may be used directly or may be processed prior to aqueous extraction. In one aspect, crucifer seeds may be defatted prior to forming an aqueous extract using known defatting procedures. For example, West, L. et al., J Arc. Food Chem. 2004, 52, 916-926, which is incorporated herein by reference. In another aspect, crucifer seeds may be ground, pulverized or blended prior to addition of aqueous extract or simultaneously with the addition of an aqueous extract.
[0010] Extraction of seed or sprouts may be conducted with water or water containing an organic solvent, such as ethyl alcohol. In another alternative aspect, an aqueous extract of crucifer seeds or sprouts is formed by contacting crucifer seeds or sprouts with water having a temperature of 60 to 110° C. for at least 5 minutes.
[0011] The aqueous extract of seeds or sprouts is contacted with an adsorbent. The aqueous extract may be separated from cellular materials and be free of seed and sprout cellular materials. Alternatively, the aqueous extract with cellular materials may be contacted directly with adsorbents. Adsorbents which may be utilized include activated carbon, silica, chemically-modified silica, bleaching clay and the like as well as and mixtures thereof. In a very important aspect, the adsorbent is activated carbon. Generally, about 1 to about 20 weight percent adsorbent is mixed with the aqueous extract. In a very important aspect, about 8 to about 12 weight percent adsorbent is mixed with the aqueous extract.
[0012] In another aspect, the aqueous extract of seeds or sprouts is added to a column containing adsorbent materials. In this aspect, column processing is effective for providing an extract having a ratio of alkyl glucosinolates, especially glucoraphanin to indole glucosinolates, specifically 4-hydroxyglucobrassicin, of about 30 to about 1000 or greater, preferably about 100 to about 1000.
[0013] In another aspect, food products are provided that include the chemoprotectant or chemoprotectant precursor enhanced extract. The extract may be incorporated directly into food products or dried, cooled, frozen or freeze-dried and then incorporated into the food products. Food product into which the extract may be incorporated include food supplements, drinks, shakes, baked goods, teas, soups, cereals, pills, tablets, salads, sandwiches, granolas, salad dressings, sauces, coffee, cheeses, yogurts, energy bars and the like as well as mixtures thereof. In this aspect, the food product may contain an amount of extract effective for providing the food product with 0.003 weight percent to 0.05 weight percent glucoraphanin.
BRIEF DESCRIPTION OF THE FIGURE
[0014] FIG. 1 provides a general description of methods for extracting chemoprotectant compounds from crucifer seeds or sprouts.
DETAILED DESCRIPTION
[0015] As shown in FIG. 1 , crucifer seeds and/or sprouts may be processed in a number of different ways. An aqueous extract of the seeds or sprouts may be formed and then mixed with adsorbents or applied to an adsorbent-containing column. Alternatively, the seeds or sprouts may be mixed directly with an aqueous extract and adsorbents. Seeds or sprouts may extracted with blending, homogenizing. or pulverizing using known methods.
[0016] As used herein “chemoprotectants” and “chemoprotective compounds” refers to agents of plant origin that are effective for reducing the susceptibility of mammals to the toxic and neoplastic effects of carcinogens. Chemoprotectant “precursors” refer to agents which give rise to chemoprotectants by enzymatic and/or chemical means. Talalay, P. et al, J. Nutr 2001, 131 (11 Suppl), 30275-30335. Examples of such chemoprotectant precursors include alkyl glucosinolates, such as glucoraphanin.
[0017] As used herein “aqueous extract” means extracts prepared with 100% water or up to 25% addition of an organic solvent, such as ethyl alcohol.
[0018] Other methods which may be used to selectively concentrate chemoprotectants and chemoprotectant precursors include: preparative liquid chromatography, membrane ultrafiltration, selective precipitation, preparative electrophoresis and preparative counter current distribution techniques. Troyer, J. et al., J. Chromatogr. A 2001, 919, 299-304; West, L. et al. J. Chromatogr. A 2002, 966, 227-232; Fahey, J. et al. J. Chromatogr. A 2003, 966, 85-93; and Iori, R., Patent Application B098A 000425 1998. In another alternative, to further purify extracts based on molecular weight, chemoprotectant precursor enhanced extract may be ultrafiltered through >500 MWCO (molecular weight cut-off) filters.
[0000] Crucifer Seeds and Sprouts
[0019] Crucifer seed and sprouts are useful starting materials. The ratio of glucoraphanin to indole glucosinolates is naturally higher in seeds (average of ˜4, with a range of 0.4 to 11) than vegetative tissue. Seeds and sprouts are preferred as a starting material since they have higher amounts of glucoraphanin as compared to mature plants. Seed and sprouts are easier to process and less expensive than mature plants.
[0020] Sprouts suitable as sources of cancer chemoprotectants are generally cruciferous sprouts (family Brassicaceae). Preferably the sprouts are Brassica oleracea ssp. selected from the group of varieties consisting of acephala (kale, collard, wild cabbage, curly kale), medullosa (marrowstem kale) ramose (thousand head kale), alboglabra (Chinese kale), botrytis (cauliflower, sprouting broccoli), costata (Portuguese kale), gemmifera (Brussels sprouts), gogylodes (kohlrabi), italica (broccoli), palmifolia (Jersey kale), sabauda (savoy cabbage), sabellica (collards), and selensia (borecole), among others. Numerous methods for the cultivation of sprouts are known, as exemplified by U.S. Pat. Nos. 3,733,745, 3,643,376, 3,945,148, 4,130,964, 4,292,769 and 4,086,725 which are all incorporated herein by reference. Sprouts may be prepared in commercial sprouters, providing water (misting 6 times/day) and light (10 hours/day) over a 5-day period.
[0021] Particularly useful broccoli cultivars to be used in the claimed method are Saga, DeCicco, Everest, Emerald City, Packman, Corvet, Dandy, Early, Emperor, Mariner, Green Comet, Green Valiant, Arcadia, Calabrese Caravel, Chancellor, Citation, Cruiser, Early Purple Sprouting Red Arrow, Eureka, Excelsior, Galleon, Ginga, Goliath, Green Duke, Greenblet, Italian Sprouting, Late Purple Sprouting, Late Winter Sprouting, White Star, Legend, Leprechaun, Marathon, Mariner, Minaret (Romanesco), Paragon, Patriot, Premium Crop, Rapine (Spring Raab), Rosalind, Salade (Fall Raab), Samurai, Shogun, Sprinter, Sultan, Taiko, Trixie, San Miguel, Arcadia, Gypsy, Everest, Patron, Southern Comet, Green Comet, Destiny, Climax and Pirate. However, many other broccoli cultivars are suitable.
[0000] Adsorbents
[0022] Crucifers seed or sprouts or aqueous extracts of crucifer seed or sprouts may be mixed directly with adsorbents in batch mode, semi-continuous mode or continuous mode (e.g. using an adsorbent column). As used herein, adsorbents refer to compounds that are effective for preferentially adsorbing indole glucosinolates over alkyl glucosinolates. Useful adsorbents include activated carbon, including Norit A and Darco 12-20 mesh granular. Additonal adsorbents demonstrating some effectiveness include silica, chemically-modified silica (so called C-18 loaded), and bleaching clay (used routinely in vegetable oil processing). Adsorbents found ineffective included alumina (neutral, acidic and basic) and Fuller's earth (montmorillonite).
[0000] Processing of Extracts
[0023] Chemoprotectant precursor enhanced extracts of crucifers seeds may be incorporated into a variety of foodstuffs. The extract may be dried, cooled, frozen or freeze-dried using known methods. Alternatively, extracts may be further processed, for example with membrane-processing or dialysis to remove high molecular weight compounds such as proteins and polysaccharides.
EXAMPLES
Example 1
Batch Processing of Broccoli Seeds
[0024] A 30 ml sample of aqueous extract from 1 g of pulverized defatted broccoli seed (var.Gypsy) was treated with 100 mg of activated carbon (Darco G-60) 12-20 mesh by boiling for 1 min. in 30 ml of water followed by filtration to remove spent adsorbent and provide an aqueous extract. The initial ratio of glucoraphanin/4-hydroxglucobrassicin of ˜11 in the initial seed was increased to ˜70 in the treated matter. Loss of glucoraphanin was ˜4% as determined by high performance liquid chromatography (HPLC), West, L. et al., J. Chromatogr. A 2002, 966, 227-232.
Example 2
Column Processing of Broccoli Seeds
[0025] A 30 ml sample of aqueous extract from 1 g of pulverized defatted broccoli seed (var Gypsy) was passed down a column containing 1000 mg of graphitized carbon black. The initial ratio of glucoraphanin/ 4 -hydroxyglucobrassicin of ˜11 in the initial seed was increased to >1000. Loss of glucoraphanin was ˜13% as determined by HPLC.
Example 3
Boiling Water Processing of Broccoli Seeds
[0026] A 100 mg portion of activated carbon (Darco G-60) was admixed with 1 g of pulverized defatted broccoli seed (var. Gypsy) and extracted in boiling water followed by centrifugation to remove particulates. The initial ratio of glucoraphanin/4-hydroxyglucobrassicin of ˜11 was increased to ˜30. Loss of glucoraphanin was ˜2% as determined by HPLC.
Example 4
Processing of Broccoli Seeds with Ultrafiltration
[0027] A 200 g. portion of pulverized and defatted (hexane extractable lipids) broccoli seed (var. Premium Crop) was added to 2 L of boiling water. After 5 min. at boiling water temperature, the mixture was filtered to remove residual plant material and the aqueous extract was treated with 20 g. of activated carbon (Darco G-60) by boiling for ˜1 min. followed by centrifugation and filtration to remove spent adsorbent. The clarified extract was ultrafiltered using a 3000 MWCO membrane all the while retaining the ultrafiltrate. After drying, the light tan in color powder was analyzed by HPLC and found to contain over 30% glucoraphanin by weight and a glucoraphanin/4-hydroxyglucobrassicin ratio of greater than 1000.
Example 5
Processing of Broccoli Sprouts with Blending and Ultrafiltration
[0028] A 500 g. sample of 5 day old whole fresh broccoli sprouts (sprouted from var. Premium Crop) were added to 2 L of boiling water. After 10 min. at boiling water temperature, the mixture was transferred to a blender operating at high speed to disrupt the plant tissue for the purpose of further releasing glucoraphanin. After filtration to remove the residual plant material, the aqueous extract was treated with 20 g. of activated carbon (Darco G-60) by boiling for ˜1 min. followed by centrifugation and filtration to remove spent adsorbent. The clarified extract was ultrafiltered using a 3000 MWCO membrane all the while retaining the ultrafiltrate. After drying, the white in color powder was analyzed by HPLC and found to contain over 10% glucoraphanin by weight and a glucoraphanin/4-hydroxyglucobrassicin ratio of greater than 1000. | The present invention is directed to chemoprotectant precursor compositions provided from crucifer seeds and sprouts and methods for their preparation. Treatment of aqueous extracts from crucifer seeds or sprouts with adsorbents substantially increases the ratio of certain highly chemoprotectant precursor compounds (alkyl glucosinolates such as glucoraphanin, a.k.a. sulforaphane glucosinolate) to undesirable compounds such as indole glucosinolates (for example 4-hydroxyglucobrassicin). The method provides an extract which has a ratio of glucoraphanin to 4-hydroxyglucobrassicin of about 70 or greater. The resulting extract has improved color and odor and may be dried or used directly as an additive in a variety of foodstuffs. | 0 |
This application is a continuation of application Ser. No. 07/899,184 filed Jun. 16, 1992 (now abandoned).
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a pulp-like composite material and a process for production thereof. More particularly, the present invention relates to a pulp-like composite material excellent in heat resistance, electrical insulation, dimensional stability and mechanical properties, as well as to a process for production thereof.
2. Prior Art
Of pulp-like materials, wood pulp is best known. Wood pulp is widely used as various paper products and also is used in a large amount as electrical insulating papers, etc.
Wood pulp, however, not only possess big drawbacks of high hygroscopicity, low heat resistance, poor dielectric property, etc. but also are unable to satisfy the requirements (e.g. heat resistance, electrical insulation, dielectric property) for smaller-sized and lighter weight electric apparatuses and appliances, i.e. electric motor, generator, transformer, etc. of smaller size and lighter weight.
Meanwhile, asbestos is used in many applications such as friction material (which is used in, for example, the brake lining, clutch facing, etc. of automobile), high-temperature gasket, packing, filtering material, building material and the like. Asbestos has problems of future unavailability due to exhaustion of asbestos resource as natural mineral and adverse effect on health due to dust generation. Hence, various attempts have been made in order to develop a substitute material for asbestos. That is, in the field of, for example, a friction material, an attempt is under way to use, as a substitute component for asbestos, a fibrous material other than asbestos, such as glass fiber, steel fiber, rock wool, carbon fiber, aramid fiber or the like.
However, the above substitute fibers for asbestos, having no pulp-like structure as possessed by asbestos, have problems in miscibility with other friction material components, productivity, etc. in production of friction material; further, the friction materials using the above substitute fibers for asbestos are insufficient in friction properties, mechanical strengths, etc.
It was also attempted to produce a pulp-like material by mixing an above-mentioned substitute fiber for asbestos, with an inorganic substance powder using a rubber or a thermoplastic resin; however, the resulting pulp-like material has a low heat resistance of 200° C. or below and is insufficient. To improve the heat resistance, an aromatic polyamide was used as the resin; the resulting pulp-like composite material, however, was inferior in compatibility with other materials, adhesion, etc.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a pulp-like composite material free from the problems possessed by wood pulp, such as flammability and poor heat resistance, and a process for production thereof. It is another object of the present invention to provide a pulp-like composite material as a possible substitute for asbestos which has such problems as future unavailability due to resource exhaustion and adverse effect on health due to dust generation and which use may be restricted in the future, and a process for production thereof.
The pulp-like composite material employed in the present invention in order to achieve the above object comprises (a) an inorganic material other than asbestos and (b) a polycarbodiimide, wherein the inorganic material (a) is substantially covered by the polycarbodiimide (b), or comprises (a) an inorganic material other than asbestos and (b) a polycarbodiimide, wherein the inorganic material (a) is substantially covered by the polycarbodiimide (b) and the coated inorganic material is connected to each other.
The process for producing a pulp-like composite material, employed in the present invention in order to achieve the above object comprises dispersing an inorganic material other than asbestos in at least either of a polycarbodiimide solution or a liquid precipitant and then mixing the resulting polycarbodiimide solution with the resulting precipitant while applying, as necessary, a shear force or a beating force.
The present inventors made a study in order to solve the above-mentioned problems. As a result, the present inventors found that, for example, by adding a mixture of a polycarbodiimide solution and an inorganic material to a precipitant to give rise to precipitation and optionally applying beating, there can be obtained a pulp-like composite material comprising an inorganic material and a polycarbodiimide, wherein the inorganic material is covered by the polycarbodiimide or is covered by the polycarbodiimide and the coated inorganic material is connected to each other (agglomerated), that the pulp-like composite material can be made into a sheet excellent in electrical insulation, heat resistance, flame resistance, mechanical properties, etc., and that the pulp-like composite material has good miscibility with other components in the field of friction material, etc. and can be used as a substitute for asbestos. The present invention has been completed based on the above finding.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a microphotograph of the pulp-like composite material obtained in Example 1.
DETAILED DESCRIPTION OF THE INVENTION
The present invention is hereinafter described in detail.
In the present invention, the pulp-like composite material is a composite material having a highly branched structure and a large surface area per unit volume. Viewed from the structure, the pulp-like composite material includes a type comprising-(a) an inorganic material other than asbestos and (b) a polycarbodiimide, wherein the inorganic material (a) is substantially covered by the polycarbodiimide (b), and a type comprising (a) an inorganic material other than asbestos and (b) a polycarbodiimide, wherein the inorganic material (a) is substantially covered by the polycarbodiimide (b) and the components of the coated inorganic material such as a plurality of coated particles or fibers are connected to each other. Depending upon the condition of covering and the mode of connection, the pulp-like composite material takes the form of particles each having a highly branched structure, bars each having a highly branched structure, or bars each having a highly branched structure formed by the connection of said particles or said bars.
In the present invention, the inorganic material includes powdery or flaky materials such as alumina, silica, kaolin, clay, talc, mica, vermiculite, potassium carbonate, barium sulfate, magnesium sulfate, potassium titanate, wollastonite and the like; and fibrous materials such as glass fiber, rock wool, silica fiber, alumina fiber, kaolin fiber, ceramic fiber, metal fiber, boron fiber, magnesia fiber, potassium titanate fiber, titanium oxide fiber and the like. These materials can be used alone or in combination of two or more.
In the present invention, the polycarbodiimide can be exemplified by a polycarbodiimide obtained by subjecting an organic diisocyanate, preferably an aromatic diisocyanate to a condensation reaction in which decarboxylation also takes place. In this condensation reaction, it is possible to use a carbodiimidization catalyst, for example, a phosphorene oxide (e.g. 3-methylphosphorene oxide). As the organic diisocyanate, there can be mentioned, for example, an aromatic diisocyanate represented by the following formula ##STR1## wherein R 1 , R 2 and R 3 each represent a lower alkyl group or a lower alkoxy group; R 4 and R 5 each represent a hydrogen atom, a lower alkyl group or a lower alkoxy group; and X represents an oxygen atom or a methylene group. These aromatic diisocyanates can be used alone or in combination of two or more.
As the polymerization solvent used in the above polycarbodiimidization, there can be mentioned alicyclic ethers such as tetrahydrofuran, 1,4-dioxane, tetrahydropyran and the like. The above-mentioned organic diisocyanate is subjected to decarboxylation and condensation in the polymerization solvent, whereby a polycarbodiimide solution can be synthesized.
The amount of the inorganic material in the present pulp-like composite material is preferably 5-95% by weight. When the amount is less than 5% by weight, the properties possessed by the inorganic material are not exhibited in the pulp-like composite material. When the amount is more than 95% by weight, the polycarbodiimide solution, when mixed with the inorganic material, has low fluidity, making difficult the practical production of pulp-like composite material.
In producing the pulp-like composite material of the present invention, there can be employed a process which comprises dispersing an inorganic material in at least either of a polycarbodiimide solution or a precipitant and then mixing the resulting polycarbodiimide solution with the resulting precipitant. In this case, the inorganic material may be dispersed in the polycarbodiimide solution by adding the inorganic material to the polymerization solvent at the time of synthesis of polycarbodiimide solution.
The concentration of polycarbodiimide in polycarbodiimide solution is preferably 2-20% by weight, although the concentration varies depending upon the type of organic diisocyanate used in polycarbodiimide synthesis, the polymerization degree of polycarbodiimide, the amount of inorganic material added, and the type of polymerization solvent.
The precipitant used in production of the present pulp-like composite material is desirably a liquid which has miscibility with the polymerization solvent used in polycarbodiimide production but which is a non-solvent to the polycarbodiimide. As the precipitant, there can be mentioned, for example, water, alcohol type solvents and acetone. These precipitants can be used alone or in combination of two or more.
In producing the present pulp-like composite material, the polycarbodiimide solution and the precipitant can be added simultaneously and mixed; or, the polycarbodiimide solution can be added to the precipitant; or reversely, the precipitant can be added to the polycarbodiimide solution. In mixing the polycarbodiimide solution with the precipitant, stirring may be conducted in order to give rise to shearing or beating. Particularly in production of a pulp-like composite material whose fiber is short and thin, it is preferable to conduct stirring.
The pulp-like composite material of the present invention can be widely used not only in electrical insulating papers but also, for its excellent heat resistance, flame resistance and mechanical properties, as synthetic papers (e.g. wallpaper), friction materials (which are used in brake lining, clutch facing, etc.), high-temperature gaskets, packings, filtering media, battery separators, sound absorbing materials, shaped materials, etc.
The present invention is hereinafter described in detail by way of Examples.
EXAMPLE 1
Synthesis of polycarbodiimide solution
In a 1,000-ml four-necked flask provided with a heating means, a thermometer, a stirrer and a condenser, were placed 40 g of diphenylmethane diisocyanate and 707 ml of tetrahydrofuran (boiling point: 65°-68° C.). Stirring was conducted so as to give a uniform mixture. Thereto was added 0.01 g of 1-phenyl-3-methyl-2-phosphorene oxide as a catalyst. The resulting mixture was heated to a temperature at which tetrahydrofuran was refluxed, and kept at that temperature for 14 hours to obtain a tetrahydrofuran solution containing a polycarbodiimide.
Production of pulp-like composite material
90 g of a barium sulfate powder was added to the above obtained polycarbodiimide solution. The mixture was stirred to obtain a uniform dispersion. 1,000 ml of water was placed in a mixer and stirred. Thereinto was gradually poured the uniform dispersion (a polycarbodiimide solution containing barium sulfate dispersed therein). Stirring was conducted for about 3 minutes, and the dispersion was fed into a nutsche type vacuum filter to obtain a pulp-like composite material by filtration. Incidentally, the filtrate was transparent and substantially no barium sulfate was detected in the filtrate.
Then, thorough water washing was conducted using the same nutsche type vacuum filter. The thus obtained pulp-like material comprising barium sulfate and a polycarbodiimide was a good pulp-like composite material having a highly branched structure. The microphotograph of the material is shown in FIG. 1.
The pulp-like composite material was made into a sheet, dried at 100° C. and hot-pressed under the conditions of 200° C. and 100 kg/cm 2 to obtain a sheet. The sheet had the following tensile strength and was good.
Tensile strength =7.5 kg/cm 2
COMPARATIVE EXAMPLE 1
A pulp-like material was obtained in the same manner as in Example 1, except that the polycarbodiimide solution was changed to an N,N-dimethylformamide solution containing a polyparaphenylene isophthalamide. The pulp-like material was made into a sheet, dried at 100° C. and hot-pressed under the conditions of 200° C. and 100 kg/cm 2 to obtain a sheet. The sheet had the following tensile strength and was insufficient.
Tensile strength=4.5 kg/cm 2 .
EXAMPLE 2
500 ml of the polycarbodiimide solution obtained in Example 1 and 90 g of barium sulfate were placed in a mixer. Stirring was conducted so as to give a uniform dispersion. Into the uniform dispersion was poured 1,000 ml of water as a precipitant to precipitate a polycarbodiimide. Stirring was conducted for about 3 minutes. The mixture was fed into a nutsche type vacuum filter to obtain a pulp-like composite material by filtration. Incidentally, the filtrate was transparent and substantially no barium sulfate was detected in the filtrate. Then, thorough water washing was conducted using the same nutsche type vacuum filter.
The thus obtained pulp-like material comprising barium sulfate and a polycarbodiimide was a good pulp-like composite material having a highly branched structure.
EXAMPLE 3
1,000 ml of water and 90 g of barium sulfate were placed in a mixer and stirred. Thereinto was gradually poured the polycarbodiimide solution obtained in Example 1. Stirring was conducted for about 3 minutes. The mixture was fed into a nutsche type vacuum filter to obtain a pulp-like composite material by filtration. Incidentally, the filtrate was transparent and substantially no barium sulfate was detected in the filtrate. Then, thorough water washing was conducted using the same nutsche type vacuum filter.
The thus obtained pulp-like material comprising barium sulfate and a polycarbodiimide was a good pulp-like composite material having a highly branched structure.
EXAMPLE 4
There was employed the same procedure for synthesis of polycarbodiimide solution as in Example 1, except that 90 g of barium sulfate was placed in the four-necked flask before heating. 500 ml of the resulting polycarbodiimide solution containing barium sulfate dispersed therein was gradually poured into 1,000 ml of water contained in a mixer with stirring. Stirring was conducted for about 3 minutes, and the dispersion was fed into a nutsche type vacuum filter to obtain a pulp-like composite material by filtration. Incidentally, the filtrate was transparent and substantially no barium sulfate was detected in the filtrate. Then, thorough water washing was conducted using the same nutsche type vacuum filter.
The thus obtained pulp-like composite material comprising barium sulfate and a polycarbodiimide was a good pulp-like composite material having a highly branched structure.
EXAMPLE 5
500 ml of the polycarbodiimide solution containing barium sulfate dispersed therein, obtained in Example 4, was placed in a mixer and stirred. Then, 1,000 ml of water as a precipitant was poured into the mixer to precipitate a polymer. Stirring was conducted for about 3 minutes, and the dispersion was fed into a nutsche type vacuum filter to obtain a pulp-like composite material by filtration. Incidentally, the filtrate was transparent and substantially no barium sulfate was detected in the filtrate. Then, thorough water washing was conducted using the same nutsche type vacuum filter.
The thus obtained pulp-like composite material comprising barium sulfate and a polycarbodiimide was a good pulp-like composite material having a highly branched structure.
EXAMPLE 6
90 g of barium sulfate was added to 500 ml of the polycarbodiimide solution obtained in Example 1. Stirring was conducted so as to give a uniform dispersion. The uniform dispersion was placed in a plate-like container. Hot water of 90° C. as a precipitant was poured into the dispersion placed in a plate-like container to precipitate a polymer. The system was allowed to stand until the temperature became room temperature. The precipitate was separated from a mixture of water and tetrahydrofuran by pressing, then dried at 100° C., and beaten by a Pallman type mill to obtain a pulp-like composite material.
The thus obtained pulp-like composite material comprising barium sulfate and a polycarbodiimide was a good pulp-like composite material having a highly branched structure.
EXAMPLE 7
Pulp-like composite materials were obtained in the same manners as in Examples 1 to 6, except that the barium sulfate was changed to mica.
Each material had a highly branched structure and was a good pulp-like composite material.
EXAMPLE 8
Pulp-like composite materials were obtained in the same manners as in Examples 1 to 6, except that the barium sulfate was changed to a barium sulfate-mica mixture (1:1 by weight).
Each material had a highly branched structure and was a good pulp-like composite material.
EXAMPLE 9
Pulp-like composite materials were obtained in the same manners as in Examples 1 to 6, except that the barium sulfate was changed to rock wool.
Each material had a highly branched structure and was a good pulp-like composite material.
EXAMPLE 10
Pulp-like composite materials were obtained in the same manners as in Examples 1 to 6, except that the barium sulfate was changed to a mica-rock wool mixture (1:1 by weight).
Each material had a highly branched structure and was a good pulp-like composite material. | The present invention provides a pulp-like composite material free from the problems possessed by wood pulp and may be used as a possible substitute for asbestos, and a process for production thereof.
The pulp-like composite material of the present invention comprises (a) an inorganic material other than asbestos and (b) a polycarbodiimide, wherein the inorganic material (a) is substantially covered by the polycarbodiimide (b), or, the inorganic material (a) is substantially covered by the polycarbodiimide (b) and the coated inorganic material is connected to each other.
The process for producing a pulp-like composite material according to the present invention comprises dispersing an inorganic material other than asbestos in at least either of a polycarbodiimide solution and a precipitant and then mixing the resulting polycarbodiimide solution with the resulting precipitant while applying, as necessary, a shear force or a beating force. | 2 |
This application is a continuation of application Ser. No. 07/135,988, filed Dec. 21, 1987 (now abandoned).
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention generally relates to a foot positioning training aid for training and instructing individuals in the proper positioning of their feet when engaged in various activities in which the position and movement of the feet are critical to proper execution of desired functions. The invention has particular utility for training individuals engaged in athletic activities such as moving or positioning a bat to engage a thrown ball, positioning and swinging a golf club to strike a stationary golf ball, positioning a racquet for optimum engagement with an approaching ball or other projectile and other similar activities. The training aid includes a generally rectangular panel which can be supported on various supporting surfaces and is provided with a raised rear edge portion and raised side edge portions to position the feet but not form barriers to movement. The side edges of the training include progressive numerical indicia and VELCRO alongside of the indicia together with positionable indicators on the VELCRO to provide indicators for initial position of the feet and also indicators to indicate movement or secondary positions of the feet for optimum performance of certain functions. The disclosure in this application relates to training a batter in striking a ball with a bat by instructing the batter in various proper batting techniques.
INFORMATION DISCLOSURE STATEMENT
There have been provided many devices to assist in training individuals in hitting a baseball, softball or the like, properly striking a golf ball, swinging a tennis racquet and the like. While such devices have accomplished beneficial results to some extent, none of the previously known devices utilize the structural arrangement of this invention and none of the devices utilize the same technique as this invention. A separate information disclosure statement will be filed.
SUMMARY OF THE INVENTION
An object of the present invention is to provide a foot positioning training aid for use in training individuals to properly position their feet when engaged in various activities and which includes a flat panel supported on a support surface and having an upper surface to be engaged by the feet of a person being trained together with position indicating arrangements associated with the panel to provide instructions to an individual as to optimum foot position and optimum foot movement when participating in certain activities.
Another object of the invention is to provide a training aid in accordance with the preceding object in which the panel is of rectangular configuration and the indicating arrangements include an upstanding edge element along one end edge and two side edges of the panel combined with numerical indicia and VELCRO strips adjustably and detachably receiving VELCRO indicators to indicate the position of the feet of an individual at a starting point and to indicate movement of one or both feet and a subsequent position of the feet during a particular activity.
A further object of the invention is to provide a training aid in accordance with the preceding objects which is especially useful in instructing individuals in proper foot positions when using a bat to bat a baseball, softball and the like with the training aid also being useful in training individuals in other sports, athletic endeavors or other endeavors in which foot position and foot movement are critical to optimum performance of such activities.
These together with other objects and advantages which will become subsequently apparent reside in the details of construction and operation as more fully hereinafter described and claimed, reference being had to the accompanying drawings forming a part hereof, wherein like numerals refer to like parts throughout.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of the foot positioning training aid of the present invention when used in training an individual in batting a thrown ball.
FIG. 2 is a perspective view of the invention illustrating the manner in which it is initially positioned with respect to a home plate.
FIG. 3 is a perspective view illustrating the invention used when training an individual in bunting a baseball or the like.
FIG. 4 is a top plan view of the training aid.
FIG. 5 is a longitudinal, sectional view, on an enlarged scale, taken along section line 5--5 on FIG. 4.
FIG. 6 is a transverse, sectional view taken along section line 6--6 on FIG. 4.
FIG. 7 is a fragmental perspective view, on an enlarged scale, illustrating the specific structural details of a side edge portion of the training aid.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now specifically to the drawings, the foot positioning training aid of the present invention is generally designated by reference numeral 10 and in the embodiment disclosed, it is associated with a conventional home plate 12 used in baseball or softball and is used to train an individual batter 14 in various phases of using a baseball bat 16 to hit a baseball that is thrown over home plate 12 in a manner described in more detail hereinafter.
The training aid 10 includes a rectangular panel 18 constructed of rubber, plastic or other material which can be positioned on a supporting surface 20 such as the ground surface, the floor of a gymnasium or any other surface area which is generally flat. The panel 18 is provided with an upper surface 22 that may be in the form of artificial turf or the like or other material that is cleat proof so that the individual 14 wearing cleated baseball shoes may effectively stand on the panel 18. While dimensions may vary to some extent, the panel 18 is solid rubber and may have dimensions of 3/4" thickness, 24" width and 42" length with the device being somewhat flexible but still capable of being self supporting on the supporting surface 20.
Along one end edge of the panel 18, a raised end element 24 is attached which is generally an inverted channel shaped rubber member or it may be a solid rubber member 24 having inclined side walls 26 at approximately 45° to the surface of the panel 18 as illustrated in FIG. 5 which forms a positioning device for the rear foot 28 of an individual batter 14 when batting right handed is illustrated in FIG. 1.
Each side edge of the panel 18 is provided with a side edge raised element 30 of generally inverted channel shaped configuration with the upper surface thereof being generally transversely arcuate and provided with numerical indicia printed thereon, formed thereon or otherwise applied thereto as indicated by reference numeral 32 with the numerical indicia 32 increasing from number 1 adjacent the end element 24 to the number 40 at the opposite end edge of the panel with the indicia 32 including transverse division lines 34 spaced at 1" increments or at some other equal spacing.
As illustrated, the side edge raised elements 30 are spaced inwardly from the side edges of the panels approximately two inches with a VELCRO strip 36 being provided on the panel 18 outwardly of the raised side edge elements 30 as illustrated in FIGS. 4, 6 and 7 with the upper surface of the VELCRO strip 36 being spaced slightly below the upper surface of the raised side edge element 30 to provide some protection for the VELCRO strip 30 which can be secured to the panel 18 in any suitable manner such as by bonding or the like.
Releaseably and movably positioned on the VELCRO strip is a plurality of indicator strips 38, which are a rectangular configuration and which have matching VELCRO material on the undersurface thereof for detachable mounting and adjustable mounting on the VELCRO strips 36. The hook and loop pile formed respectively on the strip 36 and the shorter strips 38 represent conventional fastener materials which are well known and enable the indicator strips 38 to be positioned at desired positions along the length of either of the VELCRO strips 36. By providing VELCRO strips 36 along both edges of the panel 18, the training aid 10 can be used on either side of home plate 12 to enable left-handed and right-handed batters to use the device. The VELCRO strips 36 are approximately 2" in width and extend throughout the length of the side edge of the panel 18 as illustrated in FIG. 4 with the side edge raised elements 30 being approximately 2" wide and 2" high and 39" in length since these elements terminate at the forward edge of the end raised element 24 as illustrated in FIG. 5. All of these components may be constructed of rubber, plastic or similar material with the VELCRO strips 36 and 38 being of conventional construction and provided with a flexible backing with the loop and pile material thereon to enable the VELCRO strip 36 to be easily bonded to the panel 18 and to enable the strips 38 to be distinguishably colored. In the preferred embodiment, there are four strips 38 each of which may be 4" in length or any other desired length and have a width equal to or greater than the width of the VELCRO strips 36 with three of the indicator strips 38 being one color such as grey and the other indicator strip 38 being a different distinguishable color such as red to facilitate positioning of these strips and provide observable significance to them which can be readily recognized by the individual being trained.
The five components of the present invention are easily usable and are relatively inexpensive. The panel 18 is of non-skid rubber or plastic material covered with a cleat proof surface with the raised edge elements being of solid or hollow rubber or plastic material and the VELCRO strip 36 and indicator VELCRO strips 38 being commercially available items.
The side edge elements 30 and the numerical indicia 32 thereon provide reference to a starting point and/or placement of both feet 28 and 29 when a batter is in the set position so that the hitter or batter may place the indicator strips 38 at precisely the same point or position each time that he takes a batting stance. This also provides the batter or hitter with a reference point as to the location of his feet during the stride and during each phase of hitting. Thus, the hitter will always place his feet in the same position and stride precisely in the same manner each time he hits which is important in learning his strike zone and training his body in a neuromuscular manner to react to a ball being thrown across home plate with precise timing and accuracy each time.
FIG. 2 illustrates the placement of the training aid in reference to home plate 12 which also must be precisely set at the same place during each practice. The training aid is positioned by the hitter placing his bat 16 perpendicular to the outside edge of the plate 12 at a point 81/2 inches from the front edge where the plate begins it break to the back point. The training aid 10 is then placed on the ground next to the knob 17 on the handle of the bat 16 with this line defined by the bat 16 being oriented perpendicular to the side edge of the training aid 10 and the bat 16 can also be used to adjust the training aid with respect to the length of the bat which occurs when the hitter places his bat 16 so that the knob 17 rests against the inclined edge 26 of the end member 24 in parallel relation to the side edge member 30 as illustrated in FIG. 2. One grey indicator strip 38 is then placed where the handle hits element 24 and another indicator strip is placed to the inside edge of the barrel of the bat and the red indicator strip 38 is placed directly between the two grey indicator strips and is lined up perpendicular to the line formed by the bat 16 when it is positioned across home plate in the manner indicated in FIG. 2. Thus, the red indicator strip will serve as a guideline for the placement of the hitter's head when in the normal batter's stance as illustrated in FIG. 1 since it is most important that the head does not move during the attempt to hit the ball inasmuch as improper movement of the head either up, down, in or out or front-to-back is caused by improper control of the body weight shift during the swing. The red indicator strip 38 positioned as illustrated in FIG. 2 will aid the hitter in keeping the head positioned over the center of gravity during the swing. The third grey strip 38 is then placed 4" in advance of the second grey strip as illustrated in FIG. 2. Thus, the purpose of the four indicator strips include marking the precise place where the hitter 14 will place his rear foot when taking his place in the simulated batter's box formed by the training aid. The second grey indicator strip will mark the precise place where the hitter will place his striding foot 29 when taking his stance and the third grey strip will indicate the precise place where the hitter should stride with his striding foot 29 with each pitch. Thus, the training aid puts the hitter at exactly the same place each time he steps to home plate.
One key factor in hitting is the hitter avoiding a swing at a pitch outside of the strike zone. The present invention allows the hitter to learn his strike zone quickly and aid him in disciplining himself to swing only at strikes. Prior to entering the batter's box during a game, the hitter is allowed to take preliminary swings at the designated on-deck circle which enables the hitter to get his timing with respect to the pitcher with the hitter preparing himself mentally and physically to hit the ball. The present invention can be used as an on-deck circle during regulation games.
Hitting a baseball may be separated into five steps, namely, stance, ready, tracking (hip turn), trigger and follow through and the present invention aids to teach proper techniques and correct common faults in each phase of hitting. At the stance phase, the hitter's toes should be aligned with the raised side element 30 which eliminates open and closed stances and allows the hitter to hit both inside and outside pitches. In an open stance, the hitter sometimes has problems with an outside pitch because the body motion seems to make the plate move away. In a closed stance, the hitter sometimes has problems with an inside pitch because the body motion causes to the plate to seem to move away. The placement of the rear foot 28 is the key to hitting to all fields. If the toes are placed perpendicular to the plate, the hitter will hit through the middle of the diamond most of the time but if the toes are pointed towards the catcher, the ball will be hit to the opposite field most of the time and if the toes are pointed towards the pitcher, the ball will be pulled most of the time. The raised end element 24 will make the hitter aware of his rear foot placement each time he steps into the batter's box. The knees are bent and positioned on the inside of both feet with the end element 24 being used by the hitter to assure proper weight distribution on the ball of the rear foot. Also, the end element 24 forces the hitter to shift his weight forward during the swing so that the heel on the rear foot can clear the element 24 during hip rotation. Also, the feet should be spread comfortably with the toes of the lead foot pointed perpendicular to the pitcher some four to six inches short of the bat length. The hips and shoulders should be level with the ground and the bat should be held in the fingers of both hands with the knuckles of both hands lined up in order to unlock the wrists and elbow joints with the bat held from perpendicular to 45° with respect to the ground. The arms are cocked with the hands and wrists relaxed and held over the rear foot in a manner by which the hands will come through first. The wrists of both hands should not roll below a straight line when the arm is extended parallel to the ground. Also, the head should be upright with the chin over the front shoulder and above the body, the eyes should be level with both of them looking at the point of release of the pitch and the elbow joints should be very relaxed and pointing towards the ground. The training aid of this invention thus aids in proper stance of the hitter preparatory to swinging and during the swing of the bat.
In the ready position in which the hands are cocked back and the front foot stride occurs as the pitcher reaches his ready position, the hitter's lead shoulder and chin should make contact and the bat is also brought into contact with the rear shoulder which helps the hitter to be aware of the location of the body parts prior to the swing and to aid in body part timing with the swing. As the hitter cocks his shoulders back, he will begin his stride position with about 60% of his body weight shifted to his back foot. The weight should remain in this distribution until after the striding foot hits the ground. The hitter should stride directly to the pitcher and try to hit the ball through the middle. The training aid of this invention prevents an incorrect stride since the hitter cannot stride closed, opened or over stride. Also, the invention enables the hitter to discipline himself so that the striding foot remains closed with both knees pointing towards the plate until the important hip turn begins with the knees kept between the feet, the hands and back of the rear foot, the waist, shoulders and eyes kept level, the chin over the lead shoulder until after the stride is complete and hips begin to open then maintaining the lead arm so that it does not straighten or lock-out, which causes loss of speed and power with the forearm of the bottom hand being held parallel to the ground and parallel to the level shoulders with the bat barrel remaining up and above the hands. The stride remains the same whether the pitch is an inside pitch, outside pitch or over the plate with the hip turn and movement of the hands differing with each pitch.
The tracking phase is aided by this invention so that when the hip and legs are committed to the ball, they will initiate movement of the hands to the ball. The hip begins the move and must clear the way for the hands with the arms, hands, wrists and elbows not moving toward the ball during tracking. Also during tracking, the bat will remain in contact with the rear shoulder, the head and chin remains still and down, the hips begin to turn towards the ball and weight begins to be shifted forward to the front leg, the knees begin to turn with the back knee initiating the move, the back hip pops forward with the arms remaining cocked until the hips clear so that power is obtained from the weight shift thereby avoiding the biggest fault of movement of the arms or upper body during hip turns. The barrel of the bat must remain up during the beginning of the hip turn with the hip tracking and turning according to the location of the pitch since the hips will not turn as much on an outside pitch as they would on an inside pitch.
The trigger phase, which is a commitment of the hands and arms to the ball, is assisted by the present invention with both elbows down, bent, compact and close to the body until the hips clear with both hands being thrown toward the ball as the body weight completes its shift to the front leg with the lead arm extending to form a straight line with the bat. At contact with the ball, the barrel of the bat should be above the hands and the hands above the ball and the hands at the point of contact will be palm down for the lead hand and palm up for the trailing hand and the back arm should lock out just after contact. Both arms will then be extended to form a triangle after contact and for maximum force, the head and eyes should remain down and the chin looking over the rear shoulder after rotation, that is, the shoulder and lower body will rotate but the head remains still.
The follow-through position includes the rolling of the wrist after the triangle is formed with the knees being between both feet during the follow-through. The bat should end up at approximately the opposite position from where it started and the head should remain still during the entire swing, which can be checked during training by using the red indicator strip 38 to determine if the head of the hitter is in line with that strip after each swing. As soon as the ball is hit, the hitter becomes a runner and the training aid of this invention allows the hitter to practice his running to first base with maximum effort each time he hits a ball.
The invention also assists in training a hitter in bunting techniques for all major types of bunts in which common positions are used. The body must be aligned with the plate, which is accomplished by the feet of the bunter being positioned with respect to the side elements and the bat must be held at the top of the strike zone and must be balanced to prevent the ball from being popped up. The bat must be placed in fair territory, forwardly of home plate, to prevent the ball from going foul. The hitter should only attempt to bunt strikes and must run full speed to first base after execution of the bunt. The training aid of the present invention enables practice of bunting techniques including positioning of the batter, the bat and reacting to pitches in the strike zone and running to first base.
While the invention has been specifically described with respect to baseball, it also can be used with softball and may also be used with other athletic activities including golf, tennis, and other activities in which the initial position and subsequent movement of the feet are important and in which it is important to locate and position the feet precisely during each training session.
Among some of the advantages and benefits derived from the use of the training aid of the present invention includes teaching hitters to stride closed with the lead foot so that lower body power is stored until the hips turn, provide adjustment of components to allow for individual batting styles, elimination of obstacles that would distract or hinder a stride during batting practice, eliminate mechanical devices which could hang up or break and possibly cause injury, provide adjustment to match individual striding style and distance, enable a hitter to place the rear foot where desired in order to dictate where the ball will be hit, enable adjustment of the batter's box in relation to home plate for each hitter with the length of the bat determining this distance and permit the batter to repetitively reproduce precisely all aspects of hitting until a desired level of skill is attained.
In addition, the device allows a hitter to practice hitting a ball off a tee, practice in any outside or inside area, enable a hitter to align himself with home plate with his center of gravity in alignment with the plate, place his head in line with home plate, enable the hitter to concentrate totally on hitting the ball and which will serve both right-handed and left-handed hitters. Essentially, this device can be used in training all aspects of an individual developing proper techniques for optimum contact with a ball by a hand manipulated implement.
The foregoing is considered as illustrative only of the principles of the invention. Further since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described, and, accordingly, all suitable modifications and equivalents may be resorted to, falling within the scope of the invention. | A foot positioning training aid for training and instructing individuals in the proper positioning of their feet when engaged in various activities in which the position and movement of the feet are critical to proper execution of desired functions. The training aid includes a generally rectangular panel which can be supported on various supporting surfaces and is provided with a raised rear edge portion and raised side edge portions to position the feet but not form barriers to movement. The side edges of the training include progress numerical indicia and VELCRO alongside of the indicia together with positionable indicators on the VELCRO to provide indicators for initial position of the feet and also indicators to indicate movement or secondary positions of the feet for optimum performance of certain functions. | 0 |
This is a division, of application Ser. No. 08/623,856, filed Mar. 26, 1996 now U.S. Pat. No. 5,844,048.
FIELD OF THE INVENTION
This invention concerns powder coating compositions that are capable of being hardened or cured by means of heat, on the basis of acrylate copolymers containing epoxide groups, together with suitable curing agents and/or pigments and/or fillers and/or additives, whereby the epoxide-containing acrylate copolymer is capable of being prepared by a polymer-like reaction of hydroxyl-functional acrylate copolymers with epihaloalkanes.
BACKGROUND OF THE INVENTION
Acrylate copolymers containing epoxide groups and their use as binding agents in powder coatings are already known: See, for example, United States patents: U.S. Pat. No. 3,781,379, U.S. Pat. No. 4,042,645 and U.S. Pat. No. 4,346,144(incorporated herein by reference). As far as the hardeners are concerned, use can be made in this connection of polybasic acids or, preferably, dibasic acids, and their anhydrides or substances that form a dibasic acid under the conditions that prevail during hardening. In principle, use can also be made of other carboxy-functional compounds as hardeners such as, for example, amorphous and/or semi-crystalline polyester resins and/or acrylate resins with free carboxy groups.
The copolymers that are described in the aforementioned patents all contain glycidyl acrylate, or, as the case may be glycidyl methacrylate. The rest of the copolymer consists of other unsaturated monomers, i.e., one is dealing here with acrylate copolymers that contain glycidyl esters. The preparation of monomeric glycidyl (meth)acrylate is not simple from a technical standpoint since glycidyl (meth)acrylate readily polymerizes, and the isolation of the pure monomer is very problematical. In addition to the short storage stability of glycidyl (meth)acrylate, its high toxicity also presents problems during processing. Thus the preparation of acrylate polymers that contain glycidyl esters via the copolymerization of glycidyl (meth)acrylate is problematical and not recommended. A further disadvantage of this process is that water cannot be used as the-reaction medium.
U.S. Pat. No. 3,294,769 (incorporated herein by reference) describes, in general, a process for the preparation of acrylate polymers that contain glycidyl ester groups via the reaction of carboxy-functional acrylate polymers with epichlorohydrin.
The saponification of methyl methacrylate polymers and their subsequent reaction with epichlorohydrin has been investigated by Sandner et al. (see, Angew. Makromol. Chem., 181: 171-182(1990) and Makromol. Chem., 192: 762-777(1991)).
SUMMARY OF THE INVENTION
It is an object of the present invention to provide thermosetting powder coating compositions comprising acrylate copolymers that contain epoxide groups, whereby the coating compositions contain special acrylate copolymers as binding agents. These compositions avoid the aforementioned disadvantages of the prior art.
This and other objects are accomplished by the coating compositions, the processes for their preparation, the methods of using such coating compositions, the processes for preparing powder coatings as well as the powder coatings themselves, which are described in the following text and in the claims.
DETAILED DESCRIPTION OF THE INVENTION
Surprisingly, it has been found that acrylate copolymers containing glycidyl ether groups can be prepared in a polymer-like reaction by reacting hydroxyl-functional acrylate copolymers with epihaloalkanes.
The subject of the invention is therefore thermosetting powder coating compositions comprising:
(A) a glycidyl ether-containing acrylate copolymer;
(B) an aliphatic and/or cycloaliphatic polybasic acid and/or its anhydride and/or a polyol-modified anhydride of a polybasic acid and/or amorphous or semi-crystalline carboxy-functional copolyester resins and/or carboxy-functional acrylate resins;
(C) and, optionally, fillers and/or pigments and/or additives; whereby the glycidyl ether-containing acrylate copolymer has a molecular weight (Mw) of 1,000 to 30,000 and a glass transition temperature of 20° C. to 120° C. and is obtainable by, in a first step, preparing a copolymer (D) that contains hydroxyl groups, which copolymer (D) is then transformed, in further steps, into an epoxide-containing acrylate copolymer (A) via reaction with epihaloalkanes. The copolymer (D) is obtainable, in particular, via the copolymerization of a monomer mixture comprising the following components:
(a) 0 to 70 parts by weight of methyl (meth)acrylate;
(b) 0 to 60 parts by weight of (cyclo)alkyl esters of acrylic acid and/or methacrylic acid with 2 to 18 carbon atoms in the alkyl or, as the case may be, in the cycloalkyl residue;
(c) 0 to 90 parts by weight of vinyl aromatic compounds and
(d) 1 to 95 parts by weight of hydroxyalkyl esters of acrylic acid and/or methacrylic acid, whereby the sum of the parts by weight of components (a) through (d) results in 100.
Hydroxyl-functional acrylate copolymers are preferred with an OH number of 10 to 400 or, preferably, from 20 to 300 mg KOH/g!.
The monomers (b) are preferably (cyclo)alkyl esters of acrylic acid or methacrylic acid with 2 to 18 carbon atoms in the (cyclo)alkyl residue. Examples of especially suitable monomers (b) are: ethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)-acrylate, isobutyl (meth)acrylate, tert.-butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, cyclohexyl methacrylate, neopentyl methacrylate, isobornyl methacrylate, 3,3,5-trimethylcyclohexyl methacrylate and stearyl methacrylate. Mixtures of the aforementioned monomers can also be used.
The monomers (c) include, for example, styrene, vinyltoluene and α-ethylstyrene.
Suitable monomers (d) are the hydroxyalkyl esters of acrylic acid and/or methacrylic acid with 2 to 6 carbon atoms, preferably 2 to 4 carbon atoms, in the hydroxyl residue such as, for example, 2-hydroxyethyl (meth)acrylate and hydroxypropyl (meth)acrylate (i.e., the mixture of isomers that is formed during the addition of propylene oxide to (meth)acrylic acid), 4-hydroxy-n-butyl acrylate or also addition products of ε-caprolactone to the aforementioned simple hydroxyalkyl esters. Thus the term "hydroxyalkyl ester" will also encompass residues having ester groups which are produced by the addition of ε-caprolactone to simple hydroxyalkyl esters with 2 to 6 carbon atoms in the hydroxyl residue. In addition, the reaction products of glycidyl (meth)acrylate with saturated monocarboxylic acids and the reaction products of (meth)acrylic acid with saturated monoepoxides, that can also carry OH groups, can be regarded as "hydroxyalkyl esters" of (meth)acrylic acid and are therefore also suitable as monomers (d).
The preparation of the copolymers can be accomplished by copolymerization of the monomers (a) to (d) already described by conventional radical-type polymerization processes such as, for example, solution polymerization, emulsion polymerization, pearl polymerization or bulk polymerization. In this connection, the monomers are copolymerized at temperatures of 60° C. to 160° C., preferably 80° C. to 150° C., in the presence of a free radical initiator together, if necessary, with molecular weight regulators.
The preparation of the hydroxyl-functional acrylate copolymers may be carried out in inert solvents. Suitable solvents are, for example, aromatic compounds such as benzene, toluene and xylene; esters, such as ethyl acetate, butyl acetate, hexyl acetate, heptyl acetate, methylglycol acetate, ethylglycol acetate and methoxypropyl acetate; ethers, such as tetrahydrofuran, dioxane, diethylene glycol dimethyl ether; ketones, such as acetone, methyl ethyl ketone, methyl isobutyl ketone; methyl n-amyl ketone, methyl isoamyl ketone or any desired mixtures of such solvents.
The preparation of the copolymers can take place either continuously or discontinuously. Usually, the monomer mixture and the initiator are evenly and continuously metered into a polymerization reactor and the corresponding quantity of polymer is continuously drained off at the same time. Chemically virtually uniform copolymers also can advantageously be prepared in this way. Chemically virtually uniform copolymers also can be prepared by allowing the reaction mixture to run, at a constant rate, in a stirred vessel without draining off the polymerizate.
A portion of the monomers can be introduced into the vessel, for example in solvents of the type described above, and then the rest of the monomers and the auxiliary agents can be introduced, separately or together, into this mixture at the reaction temperature.
In general, polymerization takes place under atmospheric pressure; however, it can also be carried out at pressures up to 25 bars. The initiators are used in quantities of 0.05 to 15% by weight based on the total quantity of the monomers.
Suitable initiators include common radical-type initiators such as, for example, aliphatic azo compounds such as azodiisobutyro-nitrile, azo-bis-2-methylvaleronitrile, 1,1'-azo-bis-1-cyclohexanecarbonitrile and the alkyl esters of 2,2'-azo-bis-isobutyric acid; symmetrical diacyl peroxides such as, for example, acetyl peroxide, propionyl peroxide or butyryl peroxide or benzoyl peroxides that have been substituted with bromine groups, nitro groups, methyl groups or methoxy groups, and lauryl peroxide; symmetrical peroxy dicarbonates, e.g., tert.-butyl perbenzoate; hydroperoxides such as, for example, tert.-butyl hydroperoxide, cumene hydroperoxide; dialkyl peroxides such as dicumyl peroxide, tert.-butylcumyl peroxide or di-tert.-butyl peroxide.
In order to regulate the molecular weight of the copolymers, use can be made of conventional regulators during the preparation. One may designate, by way of example, mercaptopropionic acid, tert.-dodecylmercaptan, n-dodecylmercaptan or diisopropyl-xanthogen disulfide. The regulators can be added in quantities of 0.1 to 10% by weight based on the total quantity of the monomers.
The solution of the copolymers generated during copolymerization can then be fed, without further processing, into an evaporation process or, as the case may be, a gas removal process, in which the solvent is removed, for example, in an evaporator extruder or spray dryer at approximately 120° C. to 160° C. under a vacuum of 100 to 300 mbars, and the copolymers that are to be used in accordance with the invention are recovered.
The reaction of the hydroxyl-functional copolymers (D) with epihaloalkanes to give the epoxide-containing acrylate copolymers (A) according to the invention takes place in the manner that is usual for the preparation of glycidyl ethers.
The glycidyl ethers of the hydroxyl-functional acrylate copolymers are obtained by reacting the hydroxyl-functional acrylate copolymer with epihaloalkanes. As a rule, this reaction takes place in a two-step process. In the first step, the epihaloalkane is added to the hydroxyl group of the acrylate copolymer, whereby a polyhalohydrin ether is formed. This reaction is catalyzed by Lewis acids such as, for example, boron trifluoride, tin tetrachloride, etc. Inert solvents such as, for example, benzene, toluene, chloroform, etc. are suitable as the solvent, or the reaction can take place in an excess of the epihaloalkane, which simultaneously serves as a solvent.
In the subsequent two steps, the glycidyl ether acrylate copolymer is formed by means of a dehydrohalogenation reaction in an inert solvent, for example, using an aqueous caustic alkali solution, for example aqueous sodium hydroxide solution.
Together with the water from the caustic alkali solution, the salt solution and water that are generated during this reaction form a specifically heavier aqueous waste liquor that can be separated in a simple manner from the organic layer after the reaction.
The reaction temperature in the first stage amounts to approximately 80° C. with a reaction time of approximately 30 minutes. The reaction temperature in the second stage amounts to 50° C. with a reaction time of approximately 60 minutes.
The reaction of the hydroxyl-functional acrylate copolymer can also take place in a first sequential reaction. In this case, one is dealing with a phase-transfer catalyzed two-phase reaction between the hydroxyl-functional acrylate copolymer, the epihaloalkane and an aqueous caustic alkali solution, preferably sodium hydroxide solution. Use is made in this connection of quaternary ammonium compounds and/or phosphonium compounds as the phase-transfer catalysts. For example, benzyltrimethylammonium bromide, tetramethylammonium bromide, benzyltrimethylammonium chloride, ethyltriphenylphosphonium bromide and butyltriphenylphosphonium chloride may be used; and benzyltrimethylammonium bromide is preferred.
The temperature for the reaction stage amounts to 60° C. with a reaction time of approximately 60 minutes. A variation of the phase transfer process is the so-called azeotropic process in which the water that is present and that is formed during the two-phase reaction is distilled off azeotropically under vacuum together with the epihaloalkane.
By way of example, the following may be designated as suitable epihaloalkanes: 1-chloro-2,3-epoxypropane (epichlorohydrin), 1-chloro-2-methyl-2,3-epoxypropane and 1-chloro-2,3-epoxybutane. 1-chloro-2,3-epoxypropane is preferred. Naturally, use can also be made, with success, of still further epihaloalkanes, e.g., epibromhydrin.
The acrylate copolymers (A), which contain epoxy groups, have a glass transition temperature of 20° C. to 120° C. The preferred glass transition temperature lies in the range from 30° C. to 90° C. The molecular weights (Mw) generally amount to 1,000 to 30,000 or, preferably, 1,000 to 20,000. The epoxide number of the epoxide-containing acrylate copolymer in accordance with the invention lies in the range from 0.018 to 0.510 or, especially, from 0.035 to 0.412 equivalents/100 g!.
Aliphatic polybasic acids, preferably, dibasic acids such as, for example, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, malonic aid, succinic acid, glutaric acid, 1,12-dodecanedioic acid, etc. can be used as the hardening agent--component (B). The anhydrides of these acids can also be used, e.g., glutaric anhydride, succinic anhydride as well as the polyanhydrides of these dicarboxylic acids. These polyanhydrides are obtained via the intermolecular condensation of the designated aliphatic dibasic dicarboxylic acids. Examples are the (poly)anhydride of adipic acid, the (poly)anhydride of azelaic acid, the (poly)anhydride of sebacic acid, the (poly)anhydride of dodecanedioic acid, etc. The polyanhydrides have a molecular weight (weight average, based on a polystyrene standard) of 1,000 to 5,000. The polyanhydrides can also be modified with a polyol.
The polyanhydrides can also be used as hardening agents when in admixture with the aliphatic dibasic dicarboxylic acids or when in admixture with hydroxycarboxylic acids that have melting points between 40° C. and 150° C., e.g., 12-hydroxystearic acid, 2-hydroxyoctadecanoic acid, 3-hydroxyoctadecanoic acid or 10-hydroxyoctadecanoic acid, and 2-hydroxymyristic acid.
Cycloaliphatic dicarboxylic acids such as, for example, 1,4-cyclohexanedicarboxylic acid or their polyanhydrides can also be used as hardening agents.
Suitable hardening agents are also amorphous and semi-crystalline copolyesters. Both the amorphous and the semi-crystalline copolyesters can be prepared in conformity with the condensation processes that are known for polyesters (esterification and/or trans-esterification) in accordance with the prior art. Suitable catalysts such as, for example, dibutyltin oxide or titanium tetrabutylate can also be used if required.
Suitable amorphous carboxy-functional copolyester resins have an acid number of 10 to 200 mg KOH/g! and a glass transition temperature of >40° C. Amorphous carboxy-functional copolyesters mainly contain aromatic polybasic carboxylic acids as the acid components such as, for example, terephthalic acid, isophthalic acid, phthalic acid, pyromellitic acid, trimellitic acid, 3,6-dichlorophthalic acid, tetrachlorophthalic acid and, if available, the anhydride s!, chloride s! or ester s! thereof. Usually, they contain at least 50 mole-% of terephthalic acid and/or isophthalic acid or, preferably, 80 mole-%. The remainder of the acids (the difference up to 100 mole-%) consists of aliphatic and/or cycloaliphatic polybasic acids such as, for example, 1,4-cyclohexanedicarboxylic acid, tetrahydrophthalic acid, hexahydroendomethyleneterephthalic acid, hexachlorophthalic acid, azelaic acid, sebacic acid, decanedicarboxylic acid, adipic acid, dodecanedicarboxylic acid, succinic acid, maleic acid or dimeric fatty acids, hydroxycarboxylic acids and/or lactones such as, for example, 12-hydroxystearic acid, ε-caprolactone or neopentyl glycol hydroxypivalate can also be used. Use is also made, in small quantities, of monocarboxylic acids such as, for example, benzoic acid, tertiary butylbenzoic acid, hexahydrobenzoic acid and saturated aliphatic monocarboxylic acids.
As far as suitable alcohol components are concerned, one may designate the aliphatic diols such as, for example, ethylene glycol, 1,3-propanediol, 1,2-propanediol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 2,2-dimethylpropane-1,3-diol (neopentyl glycol), 2,5-hexanediol, 1,6-hexanediol, 2,2- bis-(4-hydroxycyclohexyl)!propane, 1,4-dimethylolcyclohexane, diethylene glycol, dipropylene glycol and 2,2-bis- 4-(2-hydroxy)!phenyl propane. Polyols are also used in small quantities such as, for example, glycerol, hexanetriol, pentaerythritol, sorbitol, trimethylolethane, trimethylolpropane and tris(2-hydroxy)-isocyanurate. Epoxy compounds can also be used instead of diols or polyols. The proportion of neopentyl glycol and/or propylene glycol in the alcohol component preferably amounts to at least 50 mole-% based on the total acids.
Suitable semi-crystalline polyesters have an acid number of 10 to 400 mg KOH/g! and an accurately defined DSC melting point. These semi-crystalline polyesters are the condensation products of aliphatic polyols, preferably aliphatic diols, and aliphatic and/or cycloaliphatic and/or aromatic polybasic carboxylic acids, preferably dibasic acids. By way of example, one may designate as the aliphatic polyols: ethylene glycol (1,2-ethanediol), propylene glycol (1,3-propanediol), butylene glycol (1,4-butanediol), 1,6-hexanediol, neopentyl glycol, cyclohexanedimethanol, trimethylolpropane, etc. Aliphatic diols such as, for example, ethylene glycol, butylene glycol or 1,6-hexanediol are preferred.
Suitable polybasic carboxylic acids are aliphatic dicarboxylic acids or, preferably, C 4 -C 20 dicarboxylic acids such as, for example, adipic acid, azelaic acid, sebacic acid, dodecanedicarboxylic acid, succinic acid, undecanedicarboxylic acid and the aromatic dicarboxylic acids such as, for example, terephthalic acid, isophthalic acid, phthalic acid and their hydrogenation products such as, for example, 1,4-cyclohexanedicarboxylic acid. Aliphatic dicarboxylic acids with 6 to 12 carbon atoms are preferred. Naturally, use can also be made of mixtures of various polyols and polybasic carboxylic acids. Suitable carboxy-functional acrylate polymers have an acid number of 10 to 400 mg KOH/g!.
Mixtures of variously suitable hardeners can also be used in the thermosetting powder coating compositions.
Based on the acrylic resin, the quantity of the anhydrides and/or acids that is used as the hardening agent--component (B)--can vary over a wide range and is governed by the number of epoxide groups in the acrylate resin (A). In general, a molar ratio of carboxy groups or, as the case may be, anhydride groups to epoxide groups of 0.4-1.4:1 is selected or, preferably, 0.8-1.2:1.
In the coating system according to the invention, such conventional pigments and/or fillers and/or additives can be present as are commonly used for the preparation and use of powder coatings. These include additives from the group of accelerators, flow-promoting agents and degassing agents, heat stabilizers, UV stabilizers, and/or HALS stabilizers and/or tribo-additives as well as matting agents if required such as, for example, waxes.
The preparation of the powder coatings in accordance with the invention preferably takes place in the melt as a result of the communal extrusion of all the formulation components at temperatures between 60° C. and 140° C. The extruded material is then cooled, ground and selectively sieved to a grain size that is smaller than 90 μm. Alternatively, other processes for the preparation of the powder coatings are also suitable such as, for example, mixing together the formulation components in solution, with subsequent precipitation or removal of the solvent by distillation.
The application of the powder coatings in accordance with the invention is carried out by any process commonly used for such purposes such as, for example, by means of electrostatic spraying devices (corona or tribo) or using a fluidized bed process.
Powder coatings prepared as described herein may be applied to substrates such as metal and baked for, e.g., 5-60 minutes at 160° C. to 220° C. to form a hard thermoset protective finish which is thermally stable and resistant to solvents, and which has good metal adhesion properties, good mechanical strength and high durability, e.g., against weathering.
The preparation and the properties of thermosetting powder coating compositions in accordance with the invention are illustrated below by the following examples.
Preparation of Hydroxyl-functional Acrylate Copolymers
EXAMPLES 1 AND 2
General procedure:
Part I (see Table 1) is introduced into a stainless steel reactor equipped with a stirring device, a cooling device and a heating device together with electronic temperature control. Part I is heated under nitrogen up to the point of refluxing. Part II and Part III (see Table 1) are then slowly added in parallel over a period of 3 hours, during the course of which the reaction mixture is boiled under reflux. After addition of Part II and Part III has been terminated, the reaction mixture is boiled for a further 2 hours under reflux. The solvent is then removed from the reaction mixture under vacuum.
TABLE 1______________________________________Acrylate Copolymers Containing Hydroxyl Groups(weights are in g) Example 1 Example 2______________________________________Resin No. I IIPart Ixylene 1,000.00 1,000.00Part IIditertiary-butyl peroxide 46.25 46.25xylene 78.75 78.75Part IIIhydroxyethyl methacrylate 537.43 429.89n-butyl acrylate 185.00 185.00methyl methacrylate 780.70 888.23styrene 809.38 809.38mercaptopropionic acid 57.90 57.90______________________________________
TABLE 2______________________________________Properties of Resins I and II Example 1 Example 2______________________________________Resin No. I IIOH number mg KOH/g! 98.0 78.0Tg ° C.! (calculated) 71 73Molecular weight (Mw) 7,900 7,800______________________________________
Preparation of Epoxide-containing Acrylate Copolymers of the Invention
EXAMPLE 3
560 g of resin No. I were dissolved in 2,000 g of toluene in a 20 liter reactor that is capable of being heated and that has been equipped with a thermometer, a stirrer and a reflux column. After the addition of 18 ml of boron trifluoride ethyl etherate, the temperature was increased to 80° C. and 100 g of epichlorohydrin were added dropwise over a period of one hour. After this, stirring was continued for 30 minutes at 80° C. and then the mixture was cooled to 50° C. After the addition of 200 g of aqueous caustic soda (22%), the mixture was stirred for a further hour at 50° C. After this, the aqueous phase was separated. Resin No. III was obtained (properties: see Table 3) after vacuum distillation of the organic phase at a temperature of 130° C. under reduced pressure (1 mm Hg).
EXAMPLE 4
560 g of resin No. I were dissolved in 2,000 g of toluene and 1,000 g of epichlorohydrin at 60° C. in a 20 liter reactor that is capable of being heated and that has been provided with a thermometer, a stirrer and a reflux column. After the addition of 18.6 g of benzyltrimethylammonium chloride, 200 g of aqueous caustic soda (22%) were added and the mixture stirred for one hour at 60° C. After this, the aqueous phase was separated. Resin No. IV was obtained (properties: see Table 3) after vacuum distillation of the organic phase at a temperature of 130° C. under reduced pressure (1 mm Hg).
EXAMPLE 5
700 g of resin No. II were dissolved in 2,000 g of toluene in a 20 liter reactor that is capable of being heated and that has been provided with a thermometer, a stirrer and a reflux column. After the addition of 18 ml of boron trifluoride ethyl etherate, the temperature was increased to 80° C. and 100 g of epichlorohydrin were added dropwise over a period of one hour. After this, it stirring was continued for 30 minutes at 80° C. and then the mixture was cooled to 50° C. After the addition of 200 g of aqueous caustic soda (22%), the mixture was stirred for a further hour at 50° C. After this, the aqueous phase was separated. Resin No. V was obtained (properties: see Table 3) after vacuum distillation of the organic phase at a temperature of 130° C. under reduced pressure (1 mm Hg).
EXAMPLE 6
700 g of resin No. II were dissolved in 2,000 g of toluene and 1,000 g of epichlorohydrin at 60° C. in a 20 liter reactor that is capable of being heated and that has been provided with a thermometer, a stirrer and a reflux column. After the addition of 18.6 g of benzyltrimethylammonium chloride, 200 g of aqueous caustic soda (22%) were added and the mixture stirred for one hour at 60° C. After this, the aqueous phase was separated. Resin No. VI was obtained (properties: see Table 3) after vacuum distillation of the organic phase at a temperature of 130° C. under reduced pressure (1 mm Hg).
TABLE 3______________________________________Properties of Resins III to VI Example 3 Example 4 Example 5 Example 6______________________________________Resin No. III IV V VIInitial resin I I II IIE Number 0.145 0.146 0.117 0.118 equiv./100 g!Tg ° C.! 69 70 70 71(calculated)Molecular 7,900 7,900 7,800 7,800weight (Mw)______________________________________
Preparation of Powder Coatings
EXAMPLES 7 and 8
840 parts by weight of Resin III (example 7) or Resin IV (example 8), 150 parts by weight of dodecanedicarboxylic acid, 5 parts by weight of Resiflow® PV 88 and 5 parts by weight of benzoin were mixed for 30 seconds in the dry state in a Henschel mixer at 700 RPM and then extruded in a Buss-Co-Kneader (PLK 46) extruder using a jacket temperature of 100° C., a cooled screw conveyor and a rate of rotation of the screw of 150 RPM. The extruded material was cooled, ground and selectively sieved to less than 90 μm.
The powder coatings were applied electrostatically to aluminum sheets (Q panel AL-36 5005 H 14/08 (0.8 mm)) and cured at a temperature of 200° C. using a curing time of 15 minutes.
Table 4 shows the technical properties of the resultant lacquers.
EXAMPLES 9 and 10
870 parts by weight of Resin V (example 9)or Resin VI (example 10), 120 parts by weight of dodecanedicarboxylic acid, 5 parts by weight of Resiflow® PV 88 and 5 parts by weight of benzoin were mixed for 30 seconds in the dry state in a Henschel mixer at 700 RPM and then extruded in a Buss-Co-Kneader (PLK 46) extruder using a jacket temperature of 10020 C., a cooled screw conveyor and a rate of rotation of the screw of 150 RPM. The extruded material was cooled, ground and selectively sieved to less than 90 μm.
The powder coatings were applied electrostatically to aluminum sheets (Q panel AL-36 5005 H 14/08 (0.8 mm)) and cured at a temperature of 200° C. using a curing time of 15 minutes.
Table 4 shows the technical properties of the resultant lacquers.
TABLE 4______________________________________ Example 7 Example 8 Example 9 Example 10______________________________________Resin basis III IV V VIGelation time 30 31 27 28Kofler rack200° C.Gloss 109 108 108 109(60° DIN 67530)Flow properties very good very good very good very goodErichsen penetration 9.9 9.8 9.8 9.9(DIN 53156) (mm)Cross cut 0 0 0 0(DIN 52151)Impact 30 40 30 20(ASTM D 2794,back side)______________________________________ | A method for making glycidyl ether-functional (meth)acrylate copolymers includes the step of reacting a hydroxyalkyl-functional (meth)acrylate copolymer with an epihalohydrin in the presence of a suitable catalyst. The reactants may be reacted by an addition reaction catalyzed with a Lewis acid catalyst, followed by dehydrohalogenation with aqueous alkali solution. Alternatively, the reactants may be reacted in a phase transfer reaction employing quaternary ammonium or quaternary phosphonium phase transfer catalysts. | 2 |
This is a Rule 60 divisional of U.S. patent application Ser. No. 08/254,358, filed Jun. 6, 1994, now U.S. Pat. No. 5,658,785.
FIELD OF THE INVENTION
The present invention generally relates to adeno-associated virus (AAV) materials and methods which are useful for delivering DNA to cells. More particularly, the invention relates to recombinant AAV (rAAV) genomes, to methods for packaging rAAV genomes, to stable cell lines producing rAAV and to methods for delivering genes of interest to cells utilizing the rAAV.
BACKGROUND
Adeno-associated virus (AAV) is a replication-deficient parvovirus, the single-stranded DNA genome of which is about 4.7 kb in length including 145 nucleotide inverted terminal repeat (ITRs). See FIG. 1. The nucleotide sequence of the AAV2 genome is presented in Srivastava et al., J. Virol., 45: 555-564 (1983). Cis-acting sequences directing viral DNA replication (ori), encapsidation/packaging (pkg) and host cell chromosome integration (int) are contained within the ITRs. Three AAV promoters, p5, p19, and p40 (named for their relative map locations), drive the expression of the two AAV internal open reading frames encoding rep and cap genes. The two rep promoters (p5 and p19), coupled with the differential splicing of the single AAV intron (at nucleotides 2107 and 2227), result in the production of four rep proteins (rep 78, rep 68, rep 52, and rep 40) from the rep gene. Rep proteins possess multiple enzymatic properties which are ultimately responsible for replicating the viral genome. The cap gene is expressed from the p40 promoter and it encodes the three capsid proteins VP1, VP2, and VP3. Alternative and non-consensus translational start sites are responsible for the production of the three related capsid proteins. A single consensus polyadenylation site is located at map position 95 of the AAV genome. The life cycle and genetics of AAV are reviewed in Muzyczka, Current Topics in Microbiology and Immunology, 158: 97-129 (1992).
When AAV infects a human cell, the viral genome integrates into chromosome 19 resulting in latent infection of the cell. Production of infectious virus does not occur unless the cell is infected with a helper virus (for example, adenovirus or herpesvirus). In the case of adenovirus, genes E1A, E1B, E2A, E4 and VA provide helper functions. Upon infection with a helper virus, the AAV provirus is rescued and amplified, and both AAV and adenovirus are produced.
AAV possesses unique features that make it attractive as a vector for delivering foreign DNA to cells. AAV infection of cells in culture is noncytopathic, and natural infection of humans and other animals is silent and asymptomatic. Moreover, AAV infects most (if not all) mammalian cells allowing the possibility of targeting many different tissues in vivo. Kotin et al., EMBO J., 11(13): 5071-5078 (1992) reports that the DNA genome of AAV undergoes targeted integration on chromosome 19 upon infection. Replication of the viral DNA is not required for integration, and thus helper virus is not required for this process. The AAV proviral genome is infectious as cloned DNA in plasmids which makes construction of recombinant genomes feasible. Furthermore, because the signals directing AAV replication, genome encapsidation and integration are contained within the ITRs of the AAV genome, the internal approximately 4.3 kb of the genome (encoding replication and structural capsid proteins, rep-cap) may thus be replaced with foreign DNA such as a gene cassette containing a promoter, a DNA of interest and a polyadenylation signal. Another significant feature of AAV is that it is an extremely stable and hearty virus. It easily withstands the conditions used to inactivate adenovirus (56° to 65° C. for several hours), making cold preservation of rAAV-based vaccines less critical. Finally, AAV-infected cells are not resistant to superinfection.
Various groups have studied the potential use of AAV in treatment of disease states. Patent Cooperation Treaty (PCT) Internation Publication No. WO 91/18088 published Nov. 28, 1991 and the corresponding journal article by Chatterjee et al., Science, 258: 1485-1488 (1992) describe the transduction of intracellular resistance to human immunodeficiency virus-1 (HIV-1) in human hematopoietic and non-hematopoietic cell lines using an rAAV encoding an antisense RNA specific for the HIV-1 TAR sequence and polyadenylation signal. The review article Yu et al., Gene Therapy, 1: 13-26 (1994) concerning gene therapy for HIV-1 infection lists AAV as a possible gene therapy vector for hematopoietic stem cells. The use of rAAV vectors as a delivery system for stable integration and expression of genes (in particular the cystic fibrosis transmembrane regulator gene) in cultured airway epithelial cells is described in PCT International Publication No. WO 93/24641 published Dec. 9, 1993 and in the corresponding journal article by Flotte et al., Am. J. Respir. Cell Mol. Biol., 7: 349-356 (1992). Gene therapy involving rAAV in the treatment of hemoglobinopathies and other hematopoietic diseases and in conferring cell-specific multidrug resistance is proposed in PCT International Publication No. WO 93/09239 published May 13, 1993; Muro-Cacho et al., J. Immunol., 11: 231-237 (1992); LaFace et al., Virol., 162: 483-486 (1988); and Dixit et al., Gene, 104: 253-257 (1991). Therapeutic gene delivery into glioma cells is proposed in Tenenbaum et al., Gene Therapy, 1 (Supplement 1): S80 (1994).
A reletively new concept in the field of gene transfer is that immunization may be effected by the product of a transfered gene. Several attempts at "genetic immunization" have been reported including direct DNA injection of influenza A nucleoprotein sequences Ulmer et al., Science, 259: 1475-1749 (1993)!, biolistic gun immunization with human growth hormone sequences Tang et al., Nature, 356: 152-154 (1992) and infection with retroviral vectors containing HIV-1 gp160 envelope protein sequences Warner et al., AIDS RESEARCH AND HUMAN RETROVIRUSES, 7(8): 645-655 (1991)!. While these approaches appear to be feasible, direct DNA inoculation may not provide long-lasting immune responses and serious questions of safety surround the use of retroviral vectors. The use of AAV for genetic immunization is a novel approach that is not subject to these problems.
An obstacle to the use of AAV for delivery of DNA is the lack of highly efficient schemes for encapsidation of recombinant genomes. Several methods have been described for encapsidating rAAV genomes to generate recombinant viral particles. These methods all require in trans AAV rep-cap and adenovirus helper functions. The simplest involves transfecting the rAAV genome into host cells followed by co-infection with wild-type AAV and adenovirus. See, for example, U.S. Pat. No. 4,797,368 issued Jan. 10, 1989 to Carter and Tratschin, and the corresponding journal article by Tratschin et al., Mol. Cell. Biol., 5(11): 3251-3260 (1985). This method, however, leads to unacceptably high levels of wild-type AAV. Another general strategy involves supplying the AAV functions on a second plasmid (separate from the rAAV genome) that is co-transfected with the rAAV plasmid. See, for example, Hermonat et al., Proc. Natl. Acad. Sci. USA, 81: 6466-6470 (1984) and Lebkowski et al., Mol. Cell. Biol., 8(10): 3988-3996 (1988). If no sequence overlap exists between the two plasmids, then wild-type AAV production is avoided as is described in Samulski et al., J. Virol., 63(9): 3822-3828 (1989). This strategy is inherently inefficient, however, due to the requirement for three separate DNA transfer events (co-transfection of two plasmids as well as infection with adenovirus) to generate rAAV particles. Large scale production of rAAV by this method is costly and is subject to variations in transfection efficiency.
Vincent et al., Vaccines, 90: 353-359 (1990) reports that a cell line expressing rep-cap functions could be used to package rAAV. Such methods still requires transfection of the rAAV genome into the cell line and the resulting titer of rAAV reported was very low (only about 10 3 infectious units/ml). Dutton, Genetic Engineering News, 14(1): 1 and 14-15 (Jan. 15, 1994) reports that Dr. Jane Lebkowski of Applied Immune Sciences manufactures rAAV using chimeric AAV/Epstein-Barr virus plasmids that contain a recombinant AAV genome, the hygromycin resistance gene and the EBV ori P fragment and EBNA gene. The plasmids are transfected into cells to generate stable cell lines. The stable cell lines are then transfected with wild-type AAV rep-cap functions and infected with adenovirus to produce rAAV. Like the method of Vincent, the Lebkowski packaging method requires both transfection and infection events to generate rAAV particles.
There thus exists a need in the art for efficient methods of packaging rAAV genomes and for specific rAAVs useful as vectors for DNA delivery to cells.
SUMMARY OF THE INVENTION
The present invention provides recombinant AAV (rAAV) genomes useful for delivering non-AAV DNA of interest to a cell. The rAAV genomes of the invention include AAV ITRs flanking non-AAV DNA sequences of interest and lack rep-cap sequences encoding functional rep-cap proteins. If it is desirable to express the DNA of interest as a polypeptide in the cell, the rAAV genome also includes a (constitutive or regulatable) promoter and a polyadenylation signal operably linked to the DNA of interest to form a gene cassette. The gene cassette may also include intron sequences to facilitate processing of the RNA transcript in mammalian host cells. A presently preferred gene cassette includes the following DNA segments: (1) the cytomegalovirus (CMV) immediate early promoter, (2) the rabbit β-globin intron, (3) simian immunodeficiency virus (SIV) or human immunodeficiency (HIV) rev and envelope (gp160) genes, and (4) the rabbit β-globin polyadenylation signal. The rAAV genomes of the invention may be assembled in vectors useful for transfection of cells which are permissible for infection with a helper virus of AAV (e.g., adenovirus, E1-deleted adenovirus or herpesvirus). A vector of the invention which contains a rAAV genome including the foregoing preferred gene cassette, a neomycin resistance gene, and wild-type AAV rep-cap sequences was deposited in E. coli DH5 cells with the American Type Culture Collection (ATCC), 12301 Parklawn Drive, Rockville, Md. 20852, on Jun. 1, 1994 and was assigned ATCC Accession No. 69637.
Presently preferred rAAV genomes include the SIV rev and envelope (gp160) genes, or the HIV rev and envelope genes, as the non-AAV DNA(s) of interest. Also preferred are rAAV genomes which contain sequences encoding proteins which may ameliorate neurological disorders such as: sequences encoding nerve growth factor (NGF), ciliary neurotrophic factor (CNTF), brain-derived neurotrophic factor (BDNF), neurotrophins 3 and 4/5 (NT-3 and 4/5), glial cell derived neurotrophic factor (GDNF), transforming growth factors (TGF), and acidic and basic fibroblast growth factor (a and bFGF); sequences enoding tyrosine hydroxylase (TH) and aromatic amino acid decarboxylase (AADC); sequences encoding superoxide dimutase (SOD 1 or 2), catalase and glutathione peroxidase; sequences encoding interferons, lymphokines, cytokines and antagonists thereof such as tumor necrosis factor (TNF), CD4 specific antibodies, and TNF or CD4 receptors; sequences encoding GABA receptor isolforms, the GABA synthesizing enzyme glutamic acid decarboxylase (GAD), calcium dependent potassium channels or ATP-sensitive potassium channels; and sequences encoding thymidine kinase. Recombinant AAV genomes including antisense nucleotides that affect expression of certain genes such as cell death supressor genes (e.g., bcl-2) or that affect expression of excitatory amino acid receptors (e.g., glutamate and NMDA receptors) are also contemplated for modulating neurological disorders.
Other DNA sequences of interest contemplated by the invention include sequences from pathogens including: HIV-1 and HIV-2 (sequences other than rev and gp160 sequences); human T-lymphotrophic virus types I and II; respiratory syncytial virus; parainfluenza virus types 1-4; measles virus; mumps virus; rubella virus; polio viruses types 1-3; influenza virus types A, B and C; non-human influenza viruses (avian, equine, porcine); hepatitis virus types A, B, C, D and E; rotavirus; norwalk virus; cytomegaloviruses; Epstein-Barr virus; herpes simplex virus types 1 and 2; varicella-zoster virus; human herpes virus type 6; hantavirus; adenoviruses; chlamydia pneumoniae; chlamydia trachomatis; mycoplasma pneumoniae; mycobacterium tuberculosis; atypical mycobacteria; feline leukemia virus; feline immunodeficiency virus; bovine immunodeficiency virus; equine infectious anemia virus; caprine arthritis encephalitis virus; and visna virus.
Cell lines of the invention are stably transfected with both rAAV genomes of the invention and with copies of the AAV rep and cap genes. Preferred cell lines are mammalian cell lines, for example, HeLa cell lines or 293 cell lines. Infection of the cell lines of the invention with AAV helper virus results in packaging of the rAAV genomes as infectious rAAV particles. A presently preferred stable cell line is the A64 HeLa cell line which was deposited with the ATCC on Jun. 1, 1994 and was assigned ATCC Accession No. CRL 11639. The present invention also provides stable cell lines containing AAV rep and cap sequences but no rAAV genome.
Recombinant AAV generated by the foregoing packaging process are useful for delivering the DNA of interest to cells. In vivo, rAAV may be used as antisense delivery vectors, gene therapy vectors or vaccine (i.e., genetic immunization) vectors. Treatment of disease conditions including, for example, AIDS; neurological disorders including cancer, Alzheimer's disease, Parkinson's disease, Huntington's disease, and autoimmune diseases such as multiple sclerosis, trauma, depression, migraine, pain or seizure disorders; adult T-cell leukemia; tropical spastic paraparesis; upper and lower respiratory tract infections; upper and lower respiratory tract infections; measles; mumps; rubella; polio; influenza; influenza; hepatitis; hepatitis; hepatitis; hepatitis; hepatitis; diarrhea; diarrhea; systemic cytomegalovirus infections; mononucleosis-like illness; systemic Epstein-Barr virus infections; classic infectious mononucleosis; systemic herpes simplex types 1 and 2 infections; genital herpes simplex infections; chickenpox; roseola; febrile illness due to human herpes virus type 6; pneumonia and adult respiratory distress syndrome; upper and lower respiratory tract infections; conjunctivitis; upper and lower respiratory tract infections; upper and lower respiratory tract infections; genital tract infections; upper and lower respiratory tract infections; pulmonary and extrapulmonary tuberculosis; systemic infections due to atypical mycobacteria; feline leukemia; feline AIDS; bovine AIDS; equine infectious anemia; arthritis and encephalitis in goats; and pneumonia and encephalitis in sheep are contemplated by the invention. As a vaccine vector, rAAV delivers a gene of interest to a cell and the gene is expressed in the cell. The vaccine vectors may be used to generate intracellular immunity if the gene product is cytoplasmic (e.g., if the gene product prevents integration or replication of a virus). Alternatively, extracellular/systemic immunity may be generated if the gene product is expressed on the surface of the cell or is secreted.
A host (especially a human host) may be immunized against a polypeptide of a disease-causing organism by administering to the host an immunity-inducing amount of a rAAV of the invention which encodes the polypeptide. Immunization of a human host with a rAAV of the invention involves administration by inoculation of an immunity-inducing dose of the virus by the parenteral route (e.g., by intravenous, intramuscular or subcutaneous injection), by surface scarification or by inoculation into a body cavity. Typically, one or several inoculations of between about 1000 and about 10,000,000 infectious units each, as measured in susceptible human or nonhuman primate cell lines, are sufficient to effect immunization of a human host. Virus to be used as a vaccine may be utilized in liquid or freeze-dried form (in combination with one or more suitable preservatives and/or protective agents to protect the virus during the freeze-drying process). For gene therapy (e.g., of neurological disorders which may be ameliorated by a specific gene product) a therapeutically effective dose of a rAAV of the invention which encodes the polypeptide is administered to a host in need of such treatment. The use of rAAV of the invention in the manufacture of a medicament for inducing immunity in, or providing gene therapy to, a host is contemplated.
BRIEF DESCRIPTION OF THE DRAWING
Numerous other aspects and advantages of the present invention will be apparent upon consideration of the following detailed description thereof, reference being made to the drawing wherein:
FIG. 1 is a schematic representation of the AAV genome;
FIG. 2 is a schematic representation of plasmid psub201 which was the source of AAV2 sequences utilized in the examples;
FIG. 3 is a flow diagram of the construction of a rAAV genome of the invention in vector pAAV/DMV/SIVrev-gp160;
FIG. 4 is a flow diagram of the construction of the vector pAAV/CMV/SIVrev-gp160/neo/rep-cap useful to generate a stable cell line producing rAAV of the invention; and
FIG. 5 is a schematic representation of a method for packaging rAAV utilizing stable host cell lines of the invention.
DETAILED DESCRIPTION
The present invention is illustrated by the following examples relating to the production and use of rAAV of the invention. Example 1 describes the construction of a vector including a rAAV genome containing the SIV rev and envelope (gp160) genes, while Example 2 describes the construction of a vector including the AAV rep-cap genes and a neomycin resistance gene. Example 3 sets out the construction of a vector to be used to generate stable cell lines producing rAAV from the vectors described in Examples 1 and 2. The generation of stable cell lines producing rAAV encoding the SIV rev and gp160 proteins is detailed in Example 4. Example 5 describes the generation of stable cell lines expressing the AAV rep-cap genes. Example 6 presents results of infection of various mammalian cells and cell lines with the rAAV described in Example 4 which show that gp160 protein is expressed in the infected cells.
EXAMPLE 1
A vector including a rAAV genome containing a SIV rev and envelope (gp160) gene cassette was constructed from an existing plasmid designated psub201 Samulski et al., supra!. FIG. 2 is a diagram of plasmid psub201 wherein restriction endonuclease sites are shown and abbreviated as follows: P, PvuII; X, XbaI; B, BamHI; H, HindIII; and N, NaeI. The plasmid contains a modified wild-type AAV2 genome cloned between the PvuII restriction sites. The DNA sequence of the wild-type AAV2 genome is set out in SEQ ID NO: 1. The AAV2 sequence was modified to include convenient restriction sites. Specifically, two XbaI restriction sites were added via linker addition at sequence positions 190 and 4484. These sites are internal to 191 bp inverted terminal repeats (ITRs) which included the 145 bp ITRs of the AAV genome. The insertion of these sites allows the complete removal of the internal 4.3 kb fragment containing the AAV rep-cap genes upon XbaI digestion of the plasmid. In FIG. 2, the 191 bp ITRs are designated by inverted arrows.
The rAAV genome vector of the invention (pAAV/CMV/SIVrev-gp160) was generated in several steps.
First, plasmid psub201 was digested with XbaI and the approximately 4 kb vector fragment including the AAV ITRs was isolated. A CMV gene expression cassette was then inserted between the AAV ITRs by blunt end ligation. The CMV expression cassette was derived as a 1.8 kb XbaI-AflIII DNA fragment from the vector pCMV-NEO-BAM described in Karasuyama et al., J. Exp. Med., 169: 13-25 (1989). Prior to ligation, the molecular ends were filled in using the Klenow fragment of DNA polymerase I. The CMV expression cassette contained a 750 bp portion of the CMV immediate early promoter, followed by a 640 bp intron and a 360 bp polyadenylation signal sequence which were derived from the rabbit β-globin gene. Between the intron and poly A sequences were two cloning sites: a unique BamHI site and two flanking EcoRI restriction sites. The resulting vector was named pAAV/CMV. See FIG. 3A wherein restriction endonuclease cleavage sites are shown and abbreviated as follows: B, BamHI; E, EcoRI; N, Nael; and P, PvuII.
Second, the pAAV/CMV expression vector was linerized at the BamHI site and sticky ends were blunted with Klenow. A PCR-generated, 2.7 kb SIV subgenomic fragment containing the rev and envelope (gp160) sequences SEQ ID NO: 2, Hirsch et al., Nature, 339: 389-392 (1989)! was cloned into the blunt-ended BamHI site. The resulting recombinant AAV genome vector, pAAV/CMV/SIVrev-gp160, is 8.53 kb in length. See FIG. 3B wherein restriction endonuclease cleavage sites are shown and abbreviated as follows: N, Nael and P, PvuII. The vector contains the following DNA segments in sequence: (1) an AAV ITR, (2) the CMV promoter, (3) the rabbit β-globin intron, (4) the SIV rev and envelope sequences, (5) the rabbit β-globin polyadenylation signal, and (6) an AAV ITR. In transient transfection assays of human 293 cells, this vector resulted in high levels of expression of the SIV gp160 protein as determined by radioimmunoprecipitation assays using polyclonal sera from monkeys infected with SIV.
The invention specifically contemplates substitution by standard recombinant DNA techniques of the following sequences for the SIV rev/envelope sequences in the foregoing vector: HIV-1 rev/envelope sequences (the HIV-1 MN rev/envelope sequence is set out in SEQ ID NO: 3); nerve growth factor Levi-Montalcini, Science, 237: 1154-1162 (1987)!; ciliary neurotrophic factor Manthorpe et al., beginning at p. 135 in Nerve Growth Factors, Wiley and Sons (1989)!; glial cell derived neurotrophic factor Lin et al., Science, 260: 1130-1132 (1993)!; transforming growth factors Puolakkainen et al., beginning at p. 359 in NeurotrophicFactors, Academic Press (1993)!; acidic and basic fibroblast growth factors Unsicker et al., beginning at p. 313 in Neurotrophic Factors, Academic Press (1993)!; neurotrophin 3 Maisonpierre et al., Genomics, 10: 558-568 (1991)!; brain-derived neurotrophic factor Maisonpierre, supra!; neurotrophin 4/5 Berkemeier et al., Neuron, 7: 857-866 (1991)!; tyrosine hydroxylase Grima et al., Nature, 326: 707-711 (1987)!; and aromatic amino acid decarboxylase Sumi et al., J. Neurochemistry, 55: 1075-1078 (1990)!.
EXAMPLE 2
A plasmid designated pSV40/neo/rep-cap which contains the AAV rep-cap genes and a neomycin resistance gene was constructed to be used in conjunction with the rAAV genome vector described in Example 1 to generate a stable cell line producing rAAV.
A plasmid designated pAAV/SVneo (Samulski et al., supra) was digested with EcoRI and BamHI to release a 2.7 kb insert including a 421 bp portion of the SV40 early promoter, a 1.4 kb neomycin resistance gene, and a 852 bp DNA fragment containing the SV40 small t splice site and SV40 polyadenylation signal. This released insert was cloned into the EcoRI and BamHI sites of pBLUESCRIPT KS+ (Stratagene, La Jolla, Calif.) to generate the 5.66 kb plasmid pSV40/neo. Next, the approximately 4.3 kb DNA fragment containing the AAV rep-cap genes, derived from the digestion of psub201 with XbaI as described in Example 1, was ligated into the XbaI restriction site of pSV40/neo to create the plasmid pSV40/neo/rep-cap (about 10 kb). The construction of this plasmid is detailed in first half of FIG. 4 wherein restriction endonuclease sites are shown and abbreviated as follows: B, BamHI; E, EcoRI; HindIII; P, PvuII; N, NotI; RV, EcoRV; and X, XbaI. This plasmid was functional in transient assays for rep and cap activity and was itself ultimately used to derive stable cell lines (see Example 5 below).
EXAMPLE 3
A final vector to be used to generate stable cell lines producing rAAV was generated from vector pAAV/CMV/SIVrev-gp160 (Example 1) and plasmid pSV40/neo/rep-cap (Example 2).
The construction entailed removing the neo-rep-cap gene cassette from pSV40/neo/rep-cap and inserting it into a unique NaeI site in pAAV/CMV/SIVrev-gp160 (see FIG. 3B). Specifically, vector pAAV/CMV/SIVrev-gp160/neo/rep-cap was made by agarose gel band isolating a 7.0 kb EcoRV-NotI DNA fragment containing the SV/neo and rep-cap expression domains from pSV40/neo/rep-cap. The sticky ends of the fragment were blunted with Klenow and the fragment was ligated into the blunt-ended NaeI site of pAAV/CMV/SIVrev-gp160. See FIG. 4. Vector pAAV/CMV/SIVrev-gp160/neo/rep-cap (ATCC 69637) contains the following elements: (1) the rAAV genome; (2) AAV rep-cap genes; and (3) the neomycin resistance gene.
EXAMPLE 4
The vector pAAV/CMV/SIVrev-gp160/neo/rep-cap was used to generate stable cells lines containing both the rAAV genome of the invention and AAV rep-cap genes.
HeLa cells at 70% confluency were transfected with 10 μg of pAAV/CMV/SIVrev-gp160/neo/rep-cap plasmid DNA in 100 mm dishes. Cells were transfected for 6 hours after formation of DOTAP/DNA complexes in serum minus media as prescribed by the manufacturer's protocol (Boehringer-Mannheim, Indianapolis, Ind.). Following the removal of the transfection medium, DMEM media containing 10% fetal bovine serum was added to the cells. Three days later, media supplemented with 700 μg/ml Geneticin (Gibco-BRL, Gaithersburg, Md.) was used to select for cells that stably expressed the neomycin resistance gene. Fresh Geneticin containing DMEM media was added every four days. Geneticin resistant clones were selected 10-14 days after selective media was added. A total of fifty-five colonies were selected and transferred to 24-well plates and expanded for further analysis.
The fifty-five neomycin resistant HeLa cell lines were initially screened for functional rep gene activity; twenty-one scored positive. Rep gene activity was assayed by infecting the cell lines with adenovirus type 5 (Ad5). Infection by adenovirus transactivates the rep and cap genes. This results in the replication of the rAAV genome and subsequent encapsidation of these sequences into infectious rAAV particels. A schematic representation of rAAV production is shown in FIG. 5. Following maximum Ad5-induced cytopathic effect (CPE; rounding of cells and 90% detachment from the culture flask), cell lysates were prepared and Hirt DNA (low molecular weight DNA) was isolated Hirt, J. Mol. Biol., 26: 365-369 (1967)!. Southern blot analysis was used to visualize the synthesis of recombinant AAV (rAAV) replicative forms (single strand, monomeric, and dimeric forms). Control wells not receiving Ad5 were always negative. Cell lines with high relative levels of rep gene activity were selected for further study.
To assay for cap gene functionality, cell lines were infected with Ad5 and clarified lysates prepared after the development of maximum CPE. The cell lysates, Ad5, and wild-type AAV were used to infect HeLa cells. Following the development of Ad5 induced CPE (72 hr), Hirt DNA was isolated and Southern blot analysis performed. Cell line lysates that gave rise to gp160 hybridizable rAAV (SIV gp160) replicative sequences were scored positive for capsid production.
An infectious unit/ml (IU/ml) titer of rAAV produced by each cell line was derived by co-infecting C12 cells (exhibiting stable rep and cap gene expression) with Ad5 and a serial ten-fold dilution of the clarified cell line lysate to be tested. After maximum Ad5-induced CPE, Hirt DNA was isolated and Southern blot analysis performed to detect the presence of rAAV replicative forms. The end-point dilution that produced visible monomeric and dimeric replication intermediates was taken as the titer. Titer estimation was based on two to four replicate experiments.
Results of characterization of eight of the fifty-five cell lines are shown in Table 1 below wherein "ND" indicates a value was not determined.
TABLE 1______________________________________Cell Line Rep Function Cap Function Titer (IU/ml)______________________________________A5 ++ + 10.sup.4A11 ++++ + 10.sup.5A15 ++++ + 10.sup.5A37 ++++ + NDA60 +++++ - <10 .sup.1A64 +++++ + 10.sup.6A69 ++ - NDA80 ++++ + 10.sup.5______________________________________
Cell line A64 (ATCC CRL 11639) produced a high titer of rAAV (10 6 iu/ml) in clarified lysates. This titer is approximately 1000-fold higher than the titer of rAAV reported by Vincent et al., supra.
The rAAV produced by the various cell lines was also tested for its ability to express SIV gp160 in HeLa cells infected with the recombinant virus. Concentrated stocks of rAAV produced by the eight stable cell lines listed in Table 1 were generated. Cell lysates containing rAAV particles were subjected to step density gradient (CsCl) purification. After desalting dialysis and heat-inactivation of Ad5, the rAAV particles were used to infect (transduce) HeLa cells in culture. Two lines of investigation were pursued. First, the transduced cells were tested for the presence of SIV gp160-specific mRNA by performing RT-PCR on total RNA collected 72 hours after transduction. Primers specific for SIV gp160 amplified a predicted 300 bp fragment only in the presence of reverse transcriptase and Taq polymerase; samples run without reverse transcriptase were uniformly negative. Second, HeLa cells were transduced with various dilutions of the same rAAV/SIV stock as described above and, at 72 hours post transduction, indirect immunofluorescence was performed on the infected cells. At all dilutions tested (out to 1:200), cells positive for the SIV gp160 protein were detected; lower dilutions clearly had more positive cells.
The A64 cell line was tested for wild-type AAV production by a standard method. The cell line was infected with adenovirus to produce rAAV as a lysate. The lysate was then used to infect normal HeLa cells either: (i) alone; (ii) with adenovirus; or (iii) with adenovirus and wild-type AAV. As a control, HeLa cells were infected with adenovirus and wild-type AAV without rAAV. Hirt DNA was prepared and analyzed by Southern blotting (two different blots) for replicating forms of either rAAV or wild-type AAV. No wild-type AAV was detected in A64 cells not exposed to wild-type AAV.
Because the present invention involves the establishment of stable cell lines containing not only copies of the AAV rep and cap genes, but also of the rAAV genome (with ITRs flanking DNA of interest), rAAV is produced by merely infecting the cell line with adenovirus. Transfection of exogenous DNA is not required, thereby increasing the efficiency of rAAV production compared to previously described methods. Other significant features of the invention are that no wild-type AAV is produced and that scale-up for production of rAAV is easy and is limited only by normal constraints of cell growth in culture.
EXAMPLE 5
Concurrent with the generation of the stable cells described in Example 4, stable HeLa cell lines were established by similar methods which contained rep-cap genes but no rAAV genome using plasmid pSV40/neo/rep-cap (Example 2). A total of fifty-two neomycin resistant HeLa cell lines were isolated and characterized.
To test for rep gene function, each cell line was infected with Ad5 and subsequently transfected with pAAV/CMV/SIVrev-gp160. Following Ad5-induced CPE (72 hr), Hirt DNA was isolated and Southern blot analysis performed. Rep gene function was scored positive for cell lines that produced monomeric and dimeric rAAV gp160 sequences. The intensity of autoradiographic signal was used as a relative measure of rep gene expression (1-5+). Ad5 minus control samples never produced rAAV replicative forms. Cap gene proficiency was assayed in a similar manner (Ad5 infection and pAAV/CMV/SIVrev-gp160 transfection), except that a clarified cell lysate was prepared after the development of maximum CPE. HeLa cells were then co-infected with a portion of the clarified cell lysate, Ad5, and wild-type AAV. Hirt DNA was isolated 72 hours later, and hybridization analysis was used to visualize the existence of rAAV/gp160 replicative forms (monomeric and dimeric). In the assay described, the C12 cell line yielded the highest relative proportion of rAAV/gp160/120 sequences.
Results of the characterization assays are presented for eight cell lines are presented in Table 2 wherein the abbreviation "ND" indicates that a value was not determined.
TABLE 2______________________________________Cell Line Rep Function Cap Function______________________________________C2 +++++ +C12 ++++ +++C16 - NDC18 +++ NDC23 +++ NDC25 +++ -C27 ++ NDC44 ++++ +______________________________________
There are two principal uses for the stable cell lines expressing rep-cap sequences: (1) generating rAAV particles if the cell lines are transfected with a rAAV genome and infected with helper virus; and (2) determining rAAV infectious titers. To estimate rAAV infectious titers, these cell lines are co-infected with adenovirus and serial dilutions of the rAAV stock. After maximum CPE, Hirt DNA is isolated and replicative rAAV forms are visualized by Southern blot analysis. End point titration (last rAAV stock dilution to give positive hybridization signal) is then used to determine the infectious titer.
EXAMPLE 6
The ability of the rAAV produced by HeLa cell line A64 to infect (transduce) and produce SIV gp160 protein in various mammalian cell types in addition to HeLa cells (see Example 4) was assayed. The rAAV (at a multiplicity of infection of approximately 1) was used to infect cells either in a monolayer or in suspension, depending on the cell type. Three days after rAAV infection, the cells were fixed in acetone/methanol and evaluated for the production of gp160 by indirect immunofluorescence using polyclonal antisera from an SIV-infected monkey. The following cells or cell lines were infected and shown to produce gp160; fetal rat brain cells (neurons and glial cells), mouse 3T3 fibroblasts, mouse vagina, human vagina, human colon, human and monkey lymphocytes and 293 cells. No non-permissive cell type was identified. These results demonstrate that the rAAV produced by the A64 cell line infects a wide range of mammalian cell types and leads to cell surface expression of the SIV envelop gene product, gp160, in the transduced cells.
While the present invention has been described in terms of preferred embodiments, it understood that variations and improvements will occur to those skilled in the art. Therefore, only such limitations as appear in the claims should be placed on the invention.
__________________________________________________________________________SEQUENCE LISTING(1) GENERAL INFORMATION:(iii) NUMBER OF SEQUENCES: 3(2) INFORMATION FOR SEQ ID NO:1:(i) SEQUENCE CHARACTERISTICS:(A) LENGTH: 4680 base pairs(B) TYPE: nucleic acid(C) STRANDEDNESS: single(D) TOPOLOGY: linear(ii) MOLECULE TYPE: DNA (genomic)(xi) SEQUENCE DESCRIPTION: SEQ ID NO:1:TTGGCCACTCCCTCTCTGCGCGCTCGCTCGCTCACTGAGGCCGGGCGACCAAAGGTCGCC60CGACGCCCGGGCTTTGCCCGGGCGGCCTCAGTGAGCGAGCGAGCGCGCAGAGAGGGAGTG120GCCAACTCCATCACTAGGGGTTCCTGGAGGGGTGGAGTCGTGACGTGAATTACGTCATAG180GGTTAGGGAGGTCCTGTATTAGAGGTCACGTGAGTGTTTTGCGACATTTTGCGACACCAT240GTGGTCACGCTGGGTATTTAAGCCCGAGTGAGCACGCAGGGTCTCCATTTTGAAGCGGGA300GGTTTGAACGCGCAGCCGCCATGCCGGGGTTTTACGAGATTGTGATTAAGGTCCCCAGCG360ACCTTGACGGGCATCTGCCCGGCATTTCTGACAGCTTTGTGAACTGGGTGGCCGAGAAGG420AATGGGAGTTGCCGCCAGATTCTGACATGGATCTGAATCTGATTGAGCAGGCACCCCTGA480CCGTGGCCGAGAAGCTGCAGCGCGACTTTCTGACGGAATGGCGCCGTGTGAGTAAGGCCC540CGGAGGCCCTTTTCTTTGTGCAATTTGAGAAGGGAGAGAGCTACTTCCACATGCACGTGC600TCGTGGAAACCACCGGGGTGAAATCCATGGTTTTGGGACGTTTCCTGAGTCAGATTCGCG660AAAAACTGATTCAGAGAATTTACCGCGGGATCGAGCCGACTTTGCCAAACTGGTTCGCGG720TCACAAAGACCAGAAATGGCGCCGGAGGCGGGAACAAGGTGGTGGATGAGTGCTACATCC780CCAATTACTTGCTCCCCAAAACCCAGCCTGAGCTCCAGTGGGCGTGGACTAATATGGAAC840AGTATTTAAGCGCCTGTTTGAATCTCACGGAGCGTAAACGGTTGGTGGCGCAGCATCTGA900CGCACGTGTCGCAGACGCAGGAGCAGAACAAAGAGAATCAGAATCCCAATTCTGATGCGC960CGGTGATCAGATCAAAAACTTCAGCCAGGTACATGGAGCTGGTCGGGTGGCTCGTGGACA1020AGGGGATTACCTCGGAGAAGCAGTGGATCCAGGAGGACCAGGCCTCATACATCTCCTTCA1080ATGCGGCCTCCAACTCGCGGTCCCAAATCAAGGCTGCCTTGGACAATGCGGGAAAGATTA1140TGAGCCTGACTAAAACCGCCCCCGACTACCTGGTGGGCCAGCAGCCCGTGGAGGACATTT1200CCAGCAATCGGATTTATAAAATTTTGGAACTAAACGGGTACGATCCCCAATATGCGGCTT1260CCGTCTTTCTGGGATGGGCCACGAAAAAGTTCGGCAAGAGGAACACCATCTGGCTGTTTG1320GGCCTGCAACTACCGGGAAGACCAACATCGCGGAGGCCATAGCCCACACTGTGCCCTTCT1380ACGGGTGCGTAAACTGGACCAATGAGAACTTTCCCTTCAACGACTGTGTCGACAAGATGG1440TGATCTGGTGGGAGGAGGGGAAGATGACCGCCAAGGTCGTGGAGTCGGCCAAAGCCATTC1500TCGGAGGAAGCAAGGTGCGCGTGGACCAGAAATGCAAGTCCTCGGCCCAGATAGACCCGA1560CTCCCGTGATCGTCACCTCCAACACCAACATGTGCGCCGTGATTGACGGGAACTCAACGA1620CCTTCGAACACCAGCAGCCGTTGCAAGACCGGATGTTCAAATTTGAACTCACCCGCCGTC1680TGGATCATGACTTTGGGAAGGTCACCAAGCAGGAAGTCAAAGACTTTTTCCGGTGGGCAA1740AGGATCACGTGGTTGAGGTGGAGCATGAATTCTACGTCAAAAAGGGTGGAGCCAAGAAAA1800GACCCGCCCCCAGTGACGCAGATATAAGTGAGCCCAAACGGGTGCGCGAGTCAGTTGCGC1860AGCCATCGACGTCAGACGCGGAAGCTTCGATCAACTACGCAGACAGGTACCAAAACAAAT1920GTTCTCGTCACGTGGGCATGAATCTGATGCTGTTTCCCTGCAGACAATGCGAGAGAATGA1980ATCAGAATTCAAATATCTGCTTCACTCACGGACAGAAAGACTGTTTAGAGTGCTTTCCCG2040TGTCAGAATCTCAACCCGTTTCTGTCGTCAAAAAGGCGTATCAGAAACTGTGCTACATTC2100ATCATATCATGGGAAAGGTGCCAGACGCTTGCACTGCCTGCGATCTGGTCAATGTGGATT2160TGGATGACTGCATCTTTGAACAATAAATGATTTAAATCAGGTATGGCTGCCGATGGTTAT2220CTTCCAGATTGGCTCGAGGACACTCTCTCTGAAGGAATAAGACAGTGGTGGAAGCTCAAA2280CCTGGCCCACCACCACCAAAGCCCGCAGAGCGGCATAAGGACGACAGCAGGGGTCTTGTG2340CTTCCTGGGTACAAGTACCTCGGACCCTTCAACGGACTCGACAAGGGAGAGCCGGTCAAC2400GAGGCAGACGCCGCGGCCCTCGAGCACGACAAAGCCTACGACCGGCAGCTCGACAGCGGA2460GACAACCCGTACCTCAAGTACAACCACGCCGACGCGGAGTTTCAGGAGCGCCTTAAAGAA2520GATACGTCTTTTGGGGGCAACCTCGGACGAGCAGTCTTCCAGGCGAAAAAGAGGGTTCTT2580GAACCTCTGGGCCTGGTTGAGGAACCTGTTAAGACGGCTCCGGGAAAAAAGAGGCCGGTA2640GAGCACTCTCCTGTGGAGCCAGACTCCTCCTCGGGAACCGGAAAGGCGGGCCAGCAGCCT2700GCAAGAAAAAGATTGAATTTTGGTCAGACTGGAGACGCAGACTCAGTACCTGACCCCCAG2760CCTCTCGGACAGCCACCAGCAGCCCCCTCTGGTCTGGGAACTAATACGATGGCTACAGGC2820AGTGGCGCACCAATGGCAGACAATAACGAGGGCGCCGACGGAGTGGGTAATTCCTCCGGA2880AATTGGCATTGCGATTCCACATGGATGGGCGACAGAGTCATCACCACCAGCACCCGAACC2940TGGGCCCTGCCCACCTACAACAACCACCTCTACAAACAAATTTCCAGCCAATCAGGAGCC3000TCGAACGACAATCACTACTTTGGCTACAGCACCCCTTGGGGGTATTTTGACTTCAACAGA3060TTCCACTGCCACTTTTCACCACGTGACTGGCAAAGACTCATCAACAACAACTGGGGATTC3120CGACCCAAGAGACTCAACTTCAAGCTCTTTAACATTCAAGTCAAAGAGGTCACGCAGAAT3180GACGGTACGACGACGATTGCCAATAACCTTACCAGCACGGTTCAGGTGTTTACTGACTCG3240GAGTACCAGCTCCCGTACGTCCTCGGCTCGGCGCATCAAGGATGCCTCCCGCCGTTCCCA3300GCAGACGTCTTCATGGTGCCACAGTATGGATACCTCACCCTGAACAACGGGAGTCAGGCA3360GTAGGACGCTCTTCATTTTACTGCCTGGAGTACTTTCCTTCTCAGATGCTGCGTACCGGA3420AACAACTTTACCTTCAGCTACACTTTTGAGGACGTTCCTTTCCACAGCAGCTACGCTCAC3480AGCCAGAGTCTGGACCGTCTCATGAATCCTCTCATCGACCAGTACCTGTATTACTTGAGC3540AGAACAAACACTCCAAGTGGAACCACCACGCAGTCAAGGCTTCAGTTTTCTCAGGCCGGA3600GCGAGTGACATTCGGGACCAGTCTAGGAACTGGCTTCCTGGACCCTGTTACCGCCAGCAG3660CGAGTATCAAAGACATCTGCGGATAACAACAACAGTGAATACTCGTGGACTGGAGCTACC3720AAGTACCACCTCAATGGCAGAGACTCTCTGGTGAATCCGGGGCCCGCCATGGCAAGCCAC3780AAGGACGATGAAGAAAAGTTTTTTCCTCAGAGCGGGGTTCTCATCTTTGGGAAGCAAGGC3840TCAGAGAAAACAAATGTGAACATTGAAAAGGTCATGATTACAGACGAAGAGGAAATCGGA3900ACAACCAATCCCGTGGCTACGGAGCAGTATGGTTCTGTATCTACCAACCTCCAGAGAGGC3960AACAGACAAGCAGCTACCGCAGATGTCAACACACAAGGCGTTCTTCCAGGCATGGTCTGG4020CAGGACAGAGATGTGTACCTTCAGGGGCCCATCTGGGCAAAGATTCCACACACGGACGGA4080CATTTTCACCCCTCTCCCCTCATGGGTGGATTCGGACTTAAACACCCTCCTCCACAGATT4140CTCATCAAGAACACCCCGGTACCTGCGAATCCTTCGACCACCTTCAGTGCGGCAAAGTTT4200GCTTCCTTCATCACACAGTACTCCACGGGACACGGTCAGCGTGGAGATCGAGTGGGAGCT4260GCAGAAGGAAAACAGCAAACGCTGGAATCCCGAAATTCAGTACACTTCCAACTACAACAA4320GTCTGTTAATCGTGGACTTACCGTGGATACTAATGGCGTGTATTCAGAGCCTCGCCCCAT4380TGGCACCAGATACCTGACTCGTAATCTGTAATTGCTTGTTAATCAATAAACCGTTTAATT4440CGTTGCAGTTGAACTTTGGTCTCTGCGTATTTCTTTCTTATCTAGTTTCCATGGCTACGT4500AGATAATTAGCATGGCGGGTTAATCATTAACTACAAGGAACCCCTAGTGATGGAGTTGGC4560CACTCCCTCTCTGCGCGCTCGCTCGCTCACTGAGGCCGGGCGACCAAAGGTCGCCCGACG4620CCCGGGCTTTGCCCGGGCGGCCTCAGTGAGCGAGCGAGCGCGCAGAGAGGGAGTGGCCAA4680(2) INFORMATION FOR SEQ ID NO:2:(i) SEQUENCE CHARACTERISTICS:(A) LENGTH: 2658 base pairs(B) TYPE: nucleic acid(C) STRANDEDNESS: single(D) TOPOLOGY: linear(ii) MOLECULE TYPE: DNA (genomic)(xi) SEQUENCE DESCRIPTION: SEQ ID NO:2:ATGGGATGTCTTGGGAATCAGCTGCTTATCGCGCTCTTGCTAGTAAGTGTTTTAGAGATT60TGTTGTGTTCAATATGTAACAGTATTCTATGGTGTACCAGCATGGAAGAATGCGACAATT120CCCCTCTTCTGTGCAACCAAGAATAGGGACACTTGGGGAACAACACAATGCTTGCCAGAT180AATGATGATTACTCAGAATTGGCAATCAATGTCACAGAGGCTTTTGATGCTTGGGATAAT240ACAGTCACAGAACAAGCAATAGAGGATGTGTGGAACCTCTTTGAAACATCCATTAAGCCC300TGTGTAAAACTCACCCCACTATGTATAGCAATGAGATGTAATAAAACTGAGACAGATAGG360TGGGGTTTGACAGGAAACGCAGGGACAACAACAACAGCAATAACAACAACAGCAACACCA420AGTGTAGCAGAAAATGTTATAAATGAAAGTAATCCGGGCATAAAAAATAATAGTTGTGCA480GGCTTGGAACAGGAGCCCATGATAGGTTGTAAATTTAACATGACAGGGTTAAATAGGGAC540AAAAAGAAAGAATATAATGAAACATGGTATTCAAGAGATTTAATCTGTGAGCAGTCAGCG600AATGAAAGTGAGAGTAAATGTTACATGCATCATTGTAACACCAGTGTTATTCAAGAATCC660TGTGACAAGCATTATTGGGATGCTATTAGATTTAGATACTGTGCACCGCCAGGTTATGCT720TTGCTTAGGTGTAATGATTCAAATTATTTAGGCTTTGCTCCTAACTGTTCTAAGGTAGTG780GTTTCTTCATGCACAAGAATGATGGAGACGCAAACCTCTACTTGGTTTGGCTTCAATGGT840ACTAGGGCAGAAAATAGAACATACATTTATTGGCATGGCAAAAGTAATAGAACCATAATT900AGCTTGAATAAGTATTATAATCTAACAATGAGATGTAGAAGACCAGAAAATAAGACAGTT960TTACCAGTCACCATTATGTCAGGGTTGGTCTTCCATTCGCAGCCCATAAATGAGAGACCA1020AAACAGGCCTGGTGCTGGTTTGAAGGAAGCTGGAAAAAGGCCATCCAGGAAGTGAAGGAA1080ACCTTGGTCAAACATCCCAGGTATACGGGAACTAATGATACTAGGAAAATTAATCTAACA1140GCTCCAGCAGGAGGAGATCCAGAAGTCACTTTTATGTGGACAAATTGTCGAGGAGAATTC1200TTATATTGCAAAATGAATTGGTTTCTTAATTGGGTAGAGGACAGAGACCAAAAGGGTGGC1260AGATGGAAACAACAAAATAGGAAAGAGCAACAGAAGAAAAATTATGTGCCATGTCATATT1320AGACAAATAATCAACACGTGGCACAAAGTAGGCAAAAATGTATATTTGCCTCCTAGGGAA1380GGAGACCTGACATGCAATTCCACTGTAACTAGTCTCATAGCAGAGATAGATTGGATCAAT1440AGCAATGAGACCAATATCACCATGAGTGCAGAGGTGGCAGAACTGTATCGATTGGAGTTG1500GGAGATTACAAATTAATAGAGATTACTCCAATTGGCTTGGCCCCCACAAGTGTAAGAAGG1560TACACCACAACTGGTGCCTCAAGAAATAAGAGAGGGGTCTTTGTGCTAGGGTTCTTGGGT1620TTTCTCGCGACAGCAGGTTCTGCAATGGGCGCGGCGTCCGTGACGCTGTCGGCTCAGTCC1680CGGACTTTGTTGGCTGGGATAGTGCAGCAACAGCAACAGCTGTTGGATGTGGTCAAGAGA1740CAACAAGAATTGTTGCGACTGACCGTCTGGGGAACTAAGAACCTCCAGACTAGAGTCACT1800GCTATCGAGAAGTACCTGAAGGATCAGGCGCAGCTAAATTCATGGGGATGTGCTTTTAGG1860CAAGTCTGTCACACTACTGTACCATGGCCAAATGAAACATTGGTGCCTAATTGGAACAAT1920ATGACTTGGCAAGAGTGGGAAAGACAGGTTGACTTCCTAGAGGCAAATATAACTCAATTA1980TTAGAAGAAGCACAAATTCAGCAAGAAAAGAATATGTATGAATTGCAAAAATTAAATAGC2040TGGGATATCTTTGGCAATTGGTTTGACCTTACTTCTTGGATAAGATATATACAATATGGT2100GTACTTATAGTTCTAGGAGTAATAGGGTTAAGAATAGTAATATATGTAGTGCAAATGTTA2160GCTAGGTTAAGACAGGGTTATAGGCCAGTGTTCTCTTCCCCTCCCGCTTATGTTCAGCAG2220ATCCCTATCCACAAGGGCCAGGAACCGCCAACCAAAGAAGGAGAAGAAGGAGACGGTGGA2280GACAGAGGTGGCAGCAGATCTTGGCCTTGGCAGATAGAATATATTCATTTCCTGATCCGC2340CAGTTGATACGCCTCTTGACTTGGCTATTCAGCAGCTGCAGGGATTGGCTATTGAGGAGC2400TACCAGATCCTCCAACCAGTGCTCCAGAGCCTCTCAACGACGTTGCAAAGAGTCCGTGAA2460GTCATCAGAATTGAAATAGCCTACCTACAATATGGGTGGCGCTATTTCCAAGAAGCAGTA2520CAAGCGTGGTGGAAACTTGCGCGAGAGACTCTTGCAAGCGCGTGGGGAGACATATGGGAG2580ACTCTGGGAAGGGTTGGAAGAGGGATACTCGCAATCCCTAGGCGCATCAGGCAAGGGCTT2640GAGCTCACTCTCTTGTGA2658(2) INFORMATION FOR SEQ ID NO:3:(i) SEQUENCE CHARACTERISTICS:(A) LENGTH: 2571 base pairs(B) TYPE: nucleic acid(C) STRANDEDNESS: single(D) TOPOLOGY: linear(ii) MOLECULE TYPE: DNA (genomic)(xi) SEQUENCE DESCRIPTION: SEQ ID NO:3:ATGAGAGTGAAGGGGATCAGGAGGAATTATCAGCACTGGTGGGGATGGGGCACGATGCTC60CTTGGGTTATTAATGATCTGTAGTGCTACAGAAAAATTGTGGGTCACAGTCTATTATGGG120GTACCTGTGTGGAAAGAAGCAACCACCACTCTATTTTGTGCATCAGATGCTAAAGCATAT180GATACAGAGGTACATAATGTTTGGGCCACACAAGCCTGTGTACCCACAGACCCCAACCCA240CAAGAAGTAGAATTGGTAAATGTGACAGAAAATTTTAACATGTGGAAAAATAACATGGTA300GAACAGATGCATGAGGATATAATCAGTTTATGGGATCAAAGCCTAAAGCCATGTGTAAAA360TTAACCCCACTCTGTGTTACTTTAAATTGCACTGATTTGAGGAATACTACTAATACCAAT420AATAGTACTGCTAATAACAATAGTAATAGCGAGGGAACAATAAAGGGAGGAGAAATGAAA480AACTGCTCTTTCAATATCACCACAAGCATAAGAGATAAGATGCAGAAAGAATATGCACTT540CTTTATAAACTTGATATAGTATCAATAGATAATGATAGTACCAGCTATAGGTTGATAAGT600TGTAATACCTCAGTCATTACACAAGCTTGTCCAAAGATATCCTTTGAGCCAATTCCCATA660CACTATTGTGCCCCGGCTGGTTTTGCGATTCTAAAATGTAACGATAAAAAGTTCAGTGGA720AAAGGATCATGTAAAAATGTCAGCACAGTACAATGTACACATGGAATTAGGCCAGTAGTA780TCAACTCAACTGCTGTTAAATGGCAGTCTAGCAGAAGAAGAGGTAGTAATTAGATCTGAG840AATTTCACTGATAATGCTAAAACCATCATAGTACATCTGAATGAATCTGTACAAATTAAT900TGTACAAGACCCAACTACAATAAAAGAAAAAGGATACATATAGGACCAGGGAGAGCATTT960TATACAACAAAAAATATAATAGGAACTATAAGACAAGCACATTGTAACATTAGTAGAGCA1020AAATGGAATGACACTTTAAGACAGATAGTTAGCAAATTAAAAGAACAATTTAAGAATAAA1080ACAATAGTCTTTAATCAATCCTCAGGAGGGGACCCAGAAATTGTAATGCACAGTTTTAAT1140TGTGGAGGGGAATTTTTCTACTGTAATACATCACCACTGTTTAATAGTACTTGGAATGGT1200AATAATACTTGGAATAATACTACAGGGTCAAATAACAATATCACACTTCAATGCAAAATA1260AAACAAATTATAAACATGTGGCAGGAAGTAGGAAAAGCAATGTATGCCCCTCCCATTGAA1320GGACAAATTAGATGTTCATCAAATATTACAGGGCTACTATTAACAAGAGATGGTGGTAAG1380GACACGGACACGAACGACACCGAGATCTTCAGACCTGGAGGAGGAGATATGAGGGACAAT1440TGGAGAAGTGAATTATATAAATATAAAGTAGTAACAATTGAACCATTAGGAGTAGCACCC1500ACCAAGGCAAAGAGAAGAGTGGTGCAGAGAGAAAAAAGAGCAGCGATAGGAGCTCTGTTC1560CTTGGGTTCTTAGGAGCAGCAGGAAGCACTATGGGCGCAGCGTCAGTGACGCTGACGGTA1620CAGGCCAGACTATTATTGTCTGGTATAGTGCAACAGCAGAACAATTTGCTGAGGGCCATT1680GAGGCGCAACAGCATATGTTGCAACTCACAGTCTGGGGCATCAAGCAGCTCCAGGCAAGA1740GTCCTGGCTGTGGAAAGATACCTAAAGGATCAACAGCTCCTGGGGTTTTGGGGTTGCTCT1800GGAAAACTCATTTGCACCACTACTGTGCCTTGGAATGCTAGTTGGAGTAATAAATCTCTG1860GATGATATTTGGAATAACATGACCTGGATGCAGTGGGAAAGAGAAATTGACAATTACACA1920AGCTTAATATACTCATTACTAGAAAAATCGCAAACCCAACAAGAAAAGAATGAACAAGAA1980TTATTGGAATTGGATAAATGGGCAAGTTTGTGGAATTGGTTTGACATAACAAATTGGCTG2040TGGTATATAAAAATATTCATAATGATAGTAGGAGGCTTGGTAGGTTTAAGAATAGTTTTT2100GCTGTACTTTCTATAGTGAATAGAGTTAGGCAGGGATACTCACCATTGTCGTTGCAGACC2160CGCCCCCCAGTTCCGAGGGGACCCGACAGGCCCGAAGGAATCGAAGAAGAAGGTGGAGAG2220AGAGACAGAGACACATCCGGTCGATTAGTGCATGGATTCTTAGCAATTATCTGGGTCGAC2280CTGCGGAGCCTGTTCCTCTTCAGCTACCACCACAGAGACTTACTCTTGATTGCAGCGAGG2340ATTGTGGAACTTCTGGGACGCAGGGGGTGGGAAGTCCTCAAATATTGGTGGAATCTCCTA2400CAGTATTGGAGTCAGGAACTAAAGAGTAGTGCTGTTAGCTTGCTTAATGCCACAGCTATA2460GCAGTAGCTGAGGGGACAGATAGGGTTATAGAAGTACTGCAAAGAGCTGGTAGAGCTATT2520CTCCACATACCTACAAGAATAAGACAGGGCTTGGAAAGGGCTTTGCTATAA2571__________________________________________________________________________ | The present invention provides adeno-associated virus (AAV) materials and methods which are useful for DNA delivery to cells. More particularly, the invention provides recombinant AAV (rAAV) genomes, methods for packaging rAAV genomes, stable host cell lines producing rAAV and methods for delivering genes of interest to cells utilizing the rAAV. Particularly disclosed are rAAV useful in generating immunity to human immunodeficiency virus-1 and in therapeutic gene delivery for treatment of neurological disorders. | 2 |
CROSS REFERENCE TO RELATED APPLICATION
[0001] This application is a continuation of co-pending U.S. patent application Ser. No. 09/337,349, filed Jun. 21, 1999.
FIELD OF INVENTION
[0002] The invention generally relates to the field of digital communication systems, and more particularly to a method and apparatus for providing an explicit rate flow control signal for a multicast connection in a digital communications network, particularly an asynchronous transfer mode (ATM) network.
BACKGROUND OF INVENTION
[0003] In an ATM network, the available bit rate (ABR) service category is provided in order to cany data traffic which has no specific cell loss or delay guarantees. The ABR service category provides source-to-destination flow control that attempts, but is not guaranteed, to achieve zero cell loss. The ABR service category was defined in order to take advantage of available bandwidth within an ATM network during intervals when higher priority traffic is not completely utilizing the network capacity. In order to meet nominal cell loss guarantees ABR traffic employs a feedback loop which effectively monitors congestion at nodes throughout the network and periodically reports back to the source so that data traffic can be adjusted accordingly.
[0004] ABR flow control is achieved by the source sending special resource management (RM) cells through the network. Each switch in the network indicates its congestion status by optionally writing into the RM cell and forwarding the cell onto the next switch in the data path. Finally, the destination turns the RM cell back towards the source and the switches mark congestion information into the RM cell which is ultimately received by the source. The source then adjusts its sending rate in response to the information contained in the RM cell. In this manner, the RM cell acts as a feedback message from switches in the backward data path to the source.
[0005] The RM cell contains three fields which may be written to in order to describe the congestion status of the switch: a no increase (NI) bit which indicates that the source must not increase its sending rate; a congestion indication (CI) bit which indicates that the source must decrease its sending rate; and an explicit rate (ER) field which contains the minimum explicit rate calculated by any switch in the backward data path.
[0006] An explicit rate (ER) algorithm may be deployed at any contention point in the data path. For the purpose of this description a contention point is defined as a queuing point in which the aggregate arrival rate of cells is greater than the aggregate service rate. In the context of the present invention the service rate pertains to the capacity available to ABR and is in general time-dependent. A switch may have one or more contention points, and in practice an ER algorithm is typically deployed for every ABR queuing point in the network.
[0007] ATM protocols typically do not specify the algorithms to be used for computing ER values. This is a vendor specific choice. Many algorithms have been developed to determine the ER value associated with a connection path at a contention point. Many of these algorithms determine ER values based on certain accounting information relating to the input and/or output sides of a queuing point. For example, the algorithm described by Cathy Fulton et al, “UT: ABR Feedback Control with Tracking”, ATM Forum 96-1540 Traffic Management, attempts to track the total bandwidth available to ABR at a contention point with the aggregate arrival rate, and requires a switch to implement aggregate input and output rate monitoring at each contention point. Another ER algorithm proposed for congestion control of ABR traffic is disclosed in U.S. patent application Ser. No. 08/878,964 filed Jun. 19, 1997 by Tom Davis et al., owned by the instant assignee, which is incorporated by reference herein. This algorithm determines ER values as a function of the aggregate ABR queue depth associated with a given output port. These algorithms are based on unicast connections, and therefore are not readily extendible to multicast connections due to the increased accounting at the input side of a queuing point, which increases in proportion to the number of data streams which branch out from the queuing point. For instance, it is possible for ATM networks to permit multicast connections comprising over 4k destinations or leaves, and thus it becomes impractical to carry out a great number of simultaneous ER calculations. Hence, a more economical technique is desired.
SUMMARY OF INVENTION
[0008] The invention provides a method that applies known ER algorithms previously used with unicast connections to multicast connections in order to provide an explicit rate feedback. Broadly speaking, this is accomplished by identifying the slowest stream of a multicast connection at a contention point, applying an ER calculation using the accounting characteristics of the slowest stream at the contention point, and transmitting a result of the slowest stream ER calculation back to the data traffic source. This method is advantageous in that it can be relatively quickly and economically applied. In addition, in the preferred embodiment, the data transmission rate of the source is controlled by the slowest stream, therefore all leaves receive data substantially synchronously.
[0009] In the preferred embodiment, the multicast connection is set up as an asynchronous transfer mode (ATM) available bit rate (ABR) connection, and the step of transmitting includes writing ER calculation results in resource management (RM) cells flowing towards the source.
[0010] Also in the preferred embodiment, the contention point is a memory buffer for storing cells received from the source in a temporally ordered linked list. Multicasting is effected by copying cells from the linked list to various ports associated with various streams branching out from the contention point. A read pointer is maintained for each such stream to provide an index into the linked list, and the step of identifying the slowest stream includes identifying the read pointer associated with a temporally earliest cell in the linked list.
BRIEF DESCRIPTION OF DRAWINGS
[0011] The foregoing and other aspects of the preferred embodiments of the invention are described in greater detail below with reference to the following drawings, provided for the purposes of illustration and not of limitation, wherein:
[0012] [0012]FIG. 1 is a schematic diagram of a unidirectional unicast connection and an associated explicit rate flow control feedback signal or connection established over a reference network;
[0013] [0013]FIG. 2 is a schematic diagram of a unidirectional multicast connection and an associated explicit rate flow control feedback signal or connection established over the reference network;
[0014] [0014]FIG. 3 is a system block diagram of the architecture of a preferred network node which includes multiple queuing points therein;
[0015] [0015]FIG. 4 is a schematic diagram illustrating a data structure for effecting multicasting using a single physical memory buffer; and
[0016] [0016]FIG. 5 is a schematic diagram of an exemplary relationship between various connections and output ports on a network node.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0017] [0017]FIG. 1 illustrates the general principles of the explicit rate flow control technique in the context of an ATM network 10 . A unidirectional unicast connection is illustrated between a source CPE (customer premise equipment) 12 and a destination CPE 14 . User data flows unidirectionally between the source and destination CPE 12 and 14 over or through network nodes 15 along path 18 . In accordance with the ATM protocol, CPE 12 and 14 generate an RM cell flow 20 . The RM cell flow carries ER values calculated by contention points along path 18 back to the source CPE 12 which adjusts its data transmission rate accordingly. It will be appreciated that in a bi-directional unicast connection, each CPE 12 or 14 functions as both a ‘source’ and ‘destination’, whereby user data also flows from CPE 14 to CPE 12 and a corresponding RM cell flow is established therebetween.
[0018] There may be many potential contention points along path 18 , the number of which will depend on the type of network equipment employed. FIG. 3 shows as an non-exhaustive example only the basic architecture of a model 36170 MainStreetXpress™ network switch manufactured by Newbridge Network Corporation of Kanata, Ontario, Canada. The switch comprises a high capacity switching core 52 having N inputs 56 , any of which can be switched to any or all of N outputs 58 . The switch 50 further comprises one or more accessory or peripheral shelves 60 (only one being shown) which feature a plurality of universal card slots (UCS) 62 for housing interface cards or system cards.
[0019] One example of an interface card is cell relay card 64 . Card 64 comprises an ingress processing module 66 for converting, if necessary, incoming data from the input side of a input/output port 68 into ATM-like cells. The ingress processing module 66 also examines the VPI/VCI field of the ATM cell and, based on this field, attaches an internal tag or header to the ATM cell which is used to identify an internal address that the ATM cells should be routed t 0 . The ATM cell including the priority tag is then routed toward the switching core 52 over an ‘add’ bus 70 .
[0020] A hub card 72 , which is one type of system card, multiplexes a plurality of add buses 70 from the various interface cards on shelf 60 to a high speed “intershelf link” (ISL) bus 74 which connects the shelf 60 with the switching core 52 . The hub card also terminates the ISL bus 74 from the switching core 52 and drives a multi-drop bus 76 . In this manner, any interface or system card can communicate with any other interface or system card. In order to multiplex the add buses 70 from the various cards, the hub card 72 typically queues or buffers ABR cells so that higher priority traffic can be forwarded to the switching core 52 . The hub card is thus one example of a queuing point in the switch.
[0021] The cell relay card 64 includes a backplane or address filtering module 78 for monitoring the multi-drop bus 76 and copying or receiving any data cell thereon which is addressed to the card 64 . The multi-drop bus 76 operates at a relatively high speed, e.g., 800 Mb/s, and thus the card 64 may receive more ATM data cells then it can instantaneously deal with. In order to prevent cell loss, card 64 includes an output queuing module 80 for buffering outgoing cells. This too is a queuing point. An egress processing module 82 retrieves cells from the queues established by the queuing module 80 and maps the cells into the specific format of the interface for transmission on the output side of port 68 .
[0022] In practice, an ER calculation is typically carried out for each such queuing point. The locally computed ER value is compared to the ER field of a counter-flowing RM cell (which carries an ER value computed in relation to an upstream contention point), and if the former is less than the latter, the ER field is updated. An RM cell can thus be considered to be carrying a ‘global ER value’ which informs the source with respect to the most constraining congestion along the user data flow path 18 at a particular period of time. Nevertheless, it will be understood that the process of signaling a feedback message to the source about a queuing point includes the action of comparing the local ER value against the global ER value and not updating the latter where the local ER value is greater than the global ER value.
[0023] [0023]FIG. 2 illustrates a unidirectional multicast connection between a source CPE (customer premise equipment) 12 and multiple destination CPEs 14 A- 14 F. User data flows unidirectionally between the source and multiple destination CPEs along plural paths over or through network nodes 15 as indicated in the drawing. In accordance with the ATM protocol, each destination CPE 14 A- 14 F (or network nodej generates an RM cell flow towards the preceding network node the CPE is connected to. The network nodes consolidate the separate RM cell flows to provide a single RM cell flow back to the source CPE. (Note that the transmission rate of the single RM cell flow need not necessarily be equal to the sum of the transmission rates of the separate RM cell flows.) For example, node 15 A consolidates RM cell flows emanating from CPE 14 E, CPE 14 F and network node 15 B.
[0024] The preferred embodiment provides feedback about a contention point to source CPE 12 by identifying a slowest stream of the multicast connection at the contention point, and by using the accounting characteristics associated with the slowest stream to compute a local ER value according to a pre-specified ER algorithm. This ER value is carried or signaled back, as described above, to the source. No ER calculations are made in relation to the other streams which branch out from the contention point.
[0025] For example, consider node 15 A. An input stream of cells 11 enters input port 68 ( i ) and a copy of each cell received on that port is forwarded to three output ports 68 ( 1 ), 68 ( 2 ), and 68 ( 3 ), such that three identical (with the exception of a potential phase delay) data streams S 1 , S 2 and S 3 , branch out from the input stream I 1 . In the 36170 MainStreetXpress™ switch, the cells are buffered in the hub card 72 before being forwarded to output ports 68 ( 1 ), 68 ( 2 ), and 68 ( 3 ). The buffering technique may be effected by employing three separate buffers, one for each stream, or three logical buffers using one physical buffer, as explained in greater detail below.
[0026] Assume that the selected ER algorithm is the previously mentioned Davis et al. algorithm which computes a local ER value as a function of the aggregate queue depth or occupancy of all ABR connections associated with a particular output port. In applying the ER calculation, the slowest data stream at a particular instant of time is identified. This is the stream having the slowest data transmission rate, and thus the identification can be made by finding the slowest data transmission rate amongst streams S 1 , S 2 and S 3 . The slowest stream can also be identified by finding the output stream having the greatest phase delay with respect to the input stream. This is preferably accomplished by determining the longest queue (physical or logical) associated with streams S 1 , S 2 and S 3 . Other methods of determining the slowest stream will be apparent to those skilled in this art. Once the slowest stream is identified, its associated port is determined and the aggregate ABR queue depth associated therewith is utilized as an input to the Davis et al. ER algorithm.
[0027] In the preferred embodiment, the hub card 72 employs only one physical buffer or queue into which all cells received from input port 68 ( i ) are stored. The buffer is preferably organized as a number of temporally ordered linked lists 30 , one of which is exemplified in FIG. 4, in order to implement per VC queuing. (The links between cells 32 are shown in FIG. 4. by the arrows bearing ref. no. 34.) The hub card 72 employs read pointers RP 1 , RP 2 and RP 3 , one for each stream S 1 , S 2 and S 3 , as indexes into the linked list 30 . Since output ports 68 ( 1 ), 68 ( 2 ), and 68 ( 3 ) may provide differing data transmission rates, and since the traffic volume through these port may differ, the hub card 72 may copy cells 32 from the linked list to the output ports, and hence streams S 1 , S 2 and S 3 , at different rates. In such a system each read pointer functions as a place holder or index into the linked list for the corresponding output stream and indicates the next cell which must be copied to the output stream. When the read pointer associated with a temporally earliest cell in the linked list moves forward, and provided no other read pointer is pointing to that cell, the cell is physically de-queued since it has already been submitted to all the output ports or streams. For example, in the scenario shown in FIG. 4, cell A will be dequeued when read pointer RP 2 moves forward. In this manner, the hub card 72 provides multiple logical buffers using a single physical buffer. Accordingly, the longest logical buffer and slowest output stream amongst S 1 , S 2 and S 3 is readily identified by noting the read pointer which points to the temporally earliest cell in the linked list 30 .
[0028] As mentioned, the aggregate ABR queue depth of the port associated with the slowest stream is utilized as an input to the Davis et al. ER algorithm. In the preferred embodiment, a separate aggregate ABR queue depth (AAQD) counter is maintained for each output port. Whenever a “new” slowest stream is identified, a book-keeping adjustment is made to these counters. For instance, referring to FIG. 5, assume that at time to the slowest stream of the multicast connection is S 3 . The AAQD count at time t 0 for output port 68 ( 3 ) is equal to the depth of the linked list 30 with respect to stream S 3 plus the aggregated ABR queue depth of all other unicast connections 40 associated with output port 68 ( 3 ). The AAQD counts at time to for output ports 68 ( 1 ) and 68 ( 2 ) are equal to the aggregate ABR queue depth of unicast connections 42 and 44 associated with these ports, respectively. Note that the depth of linked list 30 is not included in these AAQD counts in order to prevent a “double accounting”. Consider that at time t 1 stream S 2 associated with port 68 ( 2 ) is identified as the slowest stream of the multicast connection at this node. In this case the AAQD count for port 68 ( 2 ) is adjusted so that it includes the depth of the linked list 30 with respect to stream S 2 , whereas the AAQD count for port 68 ( 3 ) is adjusted so that the depth of the linked list 30 with respect to stream S 3 is deducted from the previous AAQD value.
[0029] The invention has been described with a certain degree of particularity for the purposes of description. Those skilled in the art will appreciate that numerous modifications and variations may be made to the preferred embodiments disclosed herein without departing from the spirit and the scope of the invention. | A method of providing flow control feedback about a contention point such as a queuing point to a source of a multicast ATM virtual connection. The method includes (1) identifying a slowest output stream of the multicast connection at the contention point; (2) executing an explicit rate (ER) calculation only with respect to accounting characteristics of the slowest output stream at the contention point; and (3) signaling a result of the slowest stream ER calculation back to the source, preferably by updating resource management (RM) cells flowing towards the source. | 7 |
FIELD OF THE INVENTION
The invention relates to scanning in general and more particularly to a wand suitable for optically scanning a graphic symbol such as the universal product code symbol.
DESCRIPTION OF THE PRIOR ART
Many hand-held optical wands for scanning graphically coded data have been built in the past and a description of these would be a major undertaking and of little value. One of the principle problems in the construction of a satisfactory hand-held wand is to provide sufficient light or illumination of the code bearing surface which is compatible with the reflective nature of the surface. In the case of the universal product code symbol, the symbol specification only guarantees sufficient contrast in a narrow band between approximately 6,000 and 7,000 A, thus a light source must contain sufficient energy within the range specified. In addition, electromagnetic energy outside this range should be eliminated. This may be accomplished by filtering. However, filtering techniques will reduce the light energy available in the desired range in those instances where broadband sources such as incandescent illumination are utilized.
A typical functional arrangement is illustrated in FIG. 1. The particular arrangement selected for FIG. 1 is entirely unsuitable as a solution and was selected since it illustrates not only the overall problem but the major problems encountered in the construction of a satisfactory wand for handscanning a graphic symbol such as the universal product code.
The optical system illustrated in FIG. 1 has a large number of inefficiencies which render it impractical. One, the collection angles L and B are small even in an optimum design situation. Two, the incandescent light source when provided with a filter produces insufficient illumination at the graphic symbol. Three, the lenses utilized in this system introduce additional loss of signal strength. Four, at any point other than the focal point of the lens system, the detector is not examining the illuminated spot. Five, the aperture in the end of a wand structure when such is provided will fill with debris and render the device inoperative. If the aperture is protected, additional illumination losses will be incurred. Sixth, and probably the most important deficiency is the cost and difficulty of manufacture and assembly.
SUMMARY OF THE INVENTION
The invention contemplates a wand for scanning a graphic symbol such as the UPC symbol which includes a light emitting diode light source which emits light primarily in the frequencies between 6,000 and 7,000 A. A single filament light conductor coupled to the light source and to a second single filament light conductor for conveying the emitted light to the free end or terminus of the said second filament. A third filament optically connected to the said second filament for receiving reflected light from the free end thereof and a silicon solid state detector connected to receive reflected light from the said third filament. A structure is provided for joining and securely holding the three filaments within a wand body which supports in addition to the three filaments, the light source and the detector.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic diagram of an optical system useful in a wand for handscanning of a graphic symbol such as the UPC symbol. This prior art diagram is provided for illustrating the problems inherent in the design of a suitable wand;
FIG. 2 is a cross-sectional view of a wand constructed in accordance with the invention; and
FIGS. 3 and 4 are perspective view of the elements illustrated in cross-section in FIG. 2 which are used for joining the three fibers forming the optical transmission system.
DESCRIPTION OF THE PREFERRED EMBODIMENT
In the typical prior art system illustrated in FIG. 1, an incandescent light source 11 illuminates the label 12 or 12' shown in two positions via a filter 13 and a lens 14. The light reflected from the label 12 or 12' is directed onto a detector 15 via a second lens 16. The two positions for label 12 are shown to illustrate that except for the focal plane, the illuminated and viewed images differ, with a variable the problem of scanning or restricting the altitude at which the wand may be utilized efficiently. The altitude will, of course, be affected by the tilt angle; that is, the angle which the wand structure makes to the surface containing the coded label or graphically coded indicia. This structure contains all of the limitations on performance set forth above. It is illustrated here to show the problems associated with the implementation of a successful wand. In addition to the operating problems, the structure is difficult to manufacture since it contains lenses, filters and sources which must be precisely located and rigidly supported in order to function properly.
A wand constructed in accordance with the invention is illustrated in cross-section in FIG. 2. The cylindrical housing 20 shown partially in cross-section and an end cap 21 having an opening therein for the passage of a cable 22 containing the electrical conductors forms the basic pen body. Housing 20 is generally cylindrical and is provided with an end wall 23 having a centrally located opening. A second generally cylindrical member 24 having a conical portion 25 is supported within the housing 20 and the conical portion 25 protrudes through the central opening in the end wall 23 of housing 20. A nut 26 engages threads formed on the exterior surface of the conical portion 25 and clamps the member 24 against the inner surface of the end wall 23 when the nut 26 is threaded onto the conical portion 25.
A subassembly 27 is retained within a cylindical opening in member 24 and is located interiorally of the housing 20. The subassembly 27 includes a cylindrical support 28 which has an outer diameter substantially equal to the inner diameter of member 24. Mounted within cylindrical support 28 are two cylindrical retainers 29 and 30, illustrated in greater detail in FIGS. 3 and 4, respectively. Cylindrical retainer 29 protrudes beyond support 28 and engages a clearance within member 24. All of the parts with the exception of the attachment of member 24 via the nut 26 are secured together by epoxy-cementing. The assembly procedure will be described below.
Retainer 29 illustrated in FIG. 3 is cylindrical in nature and is provided with a cutout 31 having a width substantially equal to the diameter of a single optical fiber 32. The depth of the cutout is such that the center of the fiber when inserted in the cutout will fall at the center of the cylindrical retainer 29. The fiber 32 is inserted in the cutout 31 and cemented in place and trimmed to coincide with the flat surface illustrated in FIG. 3 by any convenient cutting tool and extends through an opening within the conical portion 25 to the terminus thereof as illustrated in FIG. 2.
Retainer 30, illustrated in FIG. 4, is similar to retainer 29 illustrated in FIG. 3 and is generally cylindrical in nature and includes a clearance cutout 31' which locates and supports two optical fiber strands 33 and 34. The depth of the cutout 31' is such that the tangent point or contact point of fibers 33 and 34 is located at the center of the cylindrical retainer 30. The fibers 33 and 34 are secured by cementing into the cutout 31' formed in the cylindrical retainer 30 and are trimmed flush with the surface visible in the drawings, especially FIG. 4. Fibers 33 and 34 are inserted in holes provided in an end cap 35 illustrated in FIG. 2. The fibers extend as far as the outer surface of end cap 32 where a light emitting diode 36 is cemented in contact with the end of fiber 33 and a silicon detector 37 is cemented into contact with the end of fiber 34. The cement or epoxy used will preferably match the index of refraction between the fiber ends and the light source and detector, respectively. The conductors from the light emitting diode 36 and the silicon photodetector 37 are carried out via cable 22 to a utilization device which may include an appropriate power source and detector. When light emitting diode 36 is energized, light energy is conducted via fiber 33 and fiber 32 to illuminate a graphic symbol over which the wand is being scanned. The reflected light from the symbol passes up fiber 32 and through fiber 34 where it is detected by silicon photodetector 37. The detected light causes electrical signals to be passed via the conductors in cable 22 back to the utilization device.
In assembly of the wand, the fibers 32, 33 and 34 are attached to the cylindrical retainers 29 and 30 by use of epoxy-cement. The retainers 29 and 30 are inserted into the cylindrical support 28 and cemented in place as illustrated in FIG. 2. The cement or epoxy used should preferably match the index of refraction of the butt joined fiber ends of fibers 32, 33 and 34. This assembly is then inserted into cylindrical member 24 and cemented in place. The fiber 32 is during this operation inserted through the interior opening in the conically shaped portion 25 and trimmed to terminate at the terminus of the conical portion 25. The fibers 33 and 34 are inserted in the appropriate holes in end cap 35 and attached by epoxycement to the LED 36 and silicone photodetector 37 which are at the same time cemented to cap 35. This entire assembly is inserted into the housing 20 and locked in place by nut 26. The cable 22 is attached to the LED 36 and silicon detector 37 and the end cap 21 is attached to the body of the wand 20 by any convenient means such as threads or friction fit.
It should be apparent from the above description that the wand described provides an efficient light conducting system which utilizes efficiently the low energy limited light from the light emitting diode 36 and is in addition easily and accurately assembled to provide an extremely inexpensive and rugged wand for scanning optically encoded graphic symbols. The optical design is such that the wand will operate over a wide skew angle from the perpendicular and should provide satisfactory results up to and beyond 35° off of the perpendicular when held in contact with a graphic symbol imprinted on a package or other device.
When 10 mil fibers are used for the optical fibers 32, 33 and 34, the wand is capable of resolving bars or spaces as narrow as 8 mils in width with less than a 5% change in modulation when reading 16 mil bars or spaces, thus the wand is eminently suitable for reading the UPC symbol. In addition, the termination in conical member 25 of the fiber 32 introduces no additional loss and when made flush with the end of conical member 25 introduces no additional losses while preventing an accumulation of debris or trash which may result in a loss of reflected light intensity. The wand utilizes no lenses and associated light losses concomitant with their use. It is simple in manufacture, requires no critical adjustments yet it provides a superior level of performance and is capable because of its construction of withstanding hard use and hostile environments.
While the invention has been particularly shown and described with reference to a preferred embodiment 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. | A wand suitable for scanning the universal product code (UPC) symbol uses a light emitting diode for illuminating the symbol and a silicon photodetector for receiving the reflected energy. A single optical fiber is coupled to the diode and to a portion of a second single fiber for conducting narrow bandwidth visible light centered about 6,500 A to the terminus of the wand. The reflected light energy from the symbol when it is scanned by the wand is transmitted to the silicon photodetector via the said second single fiber which is also coupled to a third single fiber which conducts the reflected light energy to the silicon detector. | 6 |
FIELD OF THE INVENTION
The present invention relates generally to trash receptacles and more particularly to an apparatus for dividing a trash receptacle into separate compartments of adjustable size for receipt of different types of trash materials in order to facilitate recycling.
BACKGROUND OF THE INVENTION
Trash disposal has become a troublesome aspect of the pollution control problem, and solutions incorporating source separation of the trash have been largely unsuccessful. At the present time, various types of trash, such as cans, paper, bottles and the like, are collected periodically and deposited in garbage dumps, land areas to be filled, incineration plants, and so on. The available trash depositories, however, are rapidly being filled by the ever-increasing quantities of trash. Accordingly, it has become necessary to develop other methods of trash disposal.
One of the trash disposal methods which is gaining increased attention involves reuse of the trash materials. This is commonly referred to as recycling the trash materials. Recycling involves the processing of certain types of trash material to a reusable form. For example, it has been estimated that approximately 85% of the wastepaper thrown out today could be recycled. Recycling necessitates segregation of the various kinds of trash materials such that they can be processed or recycled. However, segregation at the recycling facility presents such a monumental task as to render this approach impractical. Segregation at the source is the ideal solution. Accordingly, some municipal regulations require a home owner or business establishment to separate garbage into different types, for example, to separate bottles, aluminum cans, paper, plastic containers, newspapers and the like from each other not only for recycling purposes but also to reduce the amount of residual garbage which requires removal to a garbage dump, land fill or incineration plant.
Conventional garbage containers have generally been of a single chamber type so that different types of garbage can be deposited therein for subsequent removal. When required to separate garbage into different types, home owners and business establishments have usually resorted to setting aside separate containers for each type of garbage. For example, one container may be set aside for aluminum cans, a second container for plastic materials, a third container for newspapers and paper, and a fourth container for any remaining garbage. However, this requires a rather large amount of space and is not generally convenient to home owners and businesses.
In other cases, compartmented trash receptacles have been developed. Generally, these receptacles have a plurality of containers which are disposed in side-by-side relation within a common housing or which are held together by a common cover. However, there are several drawbacks associated with such receptacles. For example, the garbage-receiving compartments are often of insufficient size, making the trash receptacle ineffective and inconvenient for the user. In addition, these types of multiple-compartment trash receptacles often require cumbersome support structures, resulting in substantial manufacturing and replacement costs. Further, the individual compartments are typically difficult and time-consuming to empty. Besides these operational disadvantages, these types of receptacles are also typically not aesthetically pleasing.
In office situations, some recycling programs have required the janitorial crew to hand-sort the contents of wastebaskets to remove recyclable materials. This task is not only unpleasant, but it is also very time-consuming and labor-intensive. In addition, manual sorting can be dangerous to the worker, who puts himself at risk for cuts and other injuries.
Other office recycling programs have required office employees to use a secondary container such as a cardboard tray or additional wastebasket for placement of recyclable paper. However, these trays have met with little success, because these containers take up valuable work space, there being insufficient space on the employee's desk or elsewhere for placement of the tray. In addition, the trays are normally aesthetically displeasing.
Another complication relates to the way in which the trash is collected and handled by the housekeeping staff before it is ultimately picked up for disposal. When the above recycling programs are utilized, the housekeeping staff must empty the separate trays, wastebaskets and/or barrels, often necessitating an additional pass through the area to be cleaned. The custodian's cleaning flow pattern is broken up by the additional steps required to pick up desk trays and empty them into separate containers. In some cases, the custodian must pull an additional waste cart with him, resulting in possible damage to the furniture and additional inconvenience. This disrupts the cleaning schedule and leads to cost increases, inconvenience, and decline in morale for the housekeeping personnel.
The present invention addresses these and many other problems associated with currently available trash recycling solutions.
SUMMARY OF THE INVENTION
The present invention comprises an apparatus for dividing the wastebasket into multiple compartments for the deposit of different types of trash materials to facilitate recycling. The wastebasket divider apparatus includes a base member and a divider wall interconnected to the base member so as to define multiple compartments within the wastebasket. Adjustment means are provided for moving the position of the divider wall so as to adjust the size of the trash compartments. According to one aspect of the invention, the adjustment means is a slot formed within the bottom end of the divider wall which accommodates the base member, thereby allowing movement of the divider wall with respect to the base member.
According to another aspect of the invention, a wastebasket apparatus is disclosed in which the divider wall, positioned within the wastebasket framework, has a pair of pins at its bottom end. The pins are accommodated by a plurality of corresponding indentations formed within an opposite pair of the wastebasket framework side walls, so as to allow for adjustment of the divider wall position and adjustment of the compartment sizes. Another aspect of the wastebasket apparatus provides for a pair of grooves in the side walls which accommodate pins in the divider wall, there also being suitable support means such as brackets or clips members to maintain the divider wall in a substantially upright position.
The wastebasket divider device of the present invention is useful in a wide variety of situations, including offices, households, and any other source which generates trash materials which may at least in part be recyclable. The present invention is particularly advantageous in that it can be installed in an existing trash receptacle or wastebasket without any retrofitting or replacement of the wastebasket itself. The wastebasket divider device is completely supported within the wastebasket and remains therein at all times, including when the trash receptacle is being emptied. The wastebasket divider can easily be constructed in a variety of sizes to conform with different sizes and shapes of trash receptacles. Because an existing, conventional wastebasket is utilized, there is no change in the aesthetics of the home or office environment due to the wastebasket divider device of the present invention. In addition, the user need not expend significant amounts of money to provide completely new wastebaskets in order to achieve the benefits of a recycling program.
Another feature of the present invention is that it is simple in construction and inexpensive to manufacture. The wastebasket divider apparatus has relatively few parts, and it can be cheaply manufactured and assembled, resulting in a wastebasket divider which is rugged and durable.
Another advantage of the present invention is that additional containers for different categories of trash are not necessary, thereby saving space and improving the appearance over multiple containers. Because of the pleasing appearance and operational simplicity of the present invention, users are more likely to comply with the recycling program.
The apparatus of the present invention also reduces the time and effort required to empty multiple trash containers. With the present invention, the non-recyclable compartment and the recyclable compartment can both be emptied by the housekeeping personnel during the same stop by merely shifting the position of the divider wall during the trash emptying procedure. This allows one compartment to be closed off while another compartment is being emptied into the appropriate trash receiving receptacle.
Another advantage of the wastebasket divider of the present invention is that the size of the compartments formed by the divider are adjustable according to the different amounts of each type of trash or recyclable material generated. The divider wall can be easily adjusted by the user at any time to change the compartment sizes to compensate for different amounts of trash materials, thus allowing the device to be used by many different types of users and to meet a variety of demands.
For a better understanding of the invention, and of the advantages obtained by its use, reference should be made to the Drawing and accompanying descriptive matter, in which there are illustrated and described preferred embodiments of the invention.
BRIEF DESCRIPTION OF THE DRAWING
Referring particularly to the Drawing, wherein like reference numerals indicate like parts throughout the several views:
FIG. 1 is a perspective view of the first embodiment of the wastebasket divider device of the present invention;
FIG. 2 is a side elevational view of the wastebasket divider device illustrated in FIG. 1, positioned within a conventional wastebasket;
FIG. 3 is an enlarged perspective view of the bottom portion of the wastebasket divider device illustrated in FIGS. 1-2;
FIG. 4 is a perspective view of a second embodiment of the wastebasket apparatus of the present invention; and
FIG. 5 is a perspective view of a third embodiment of the wastebasket apparatus of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to the drawings, the preferred embodiment of the wastebasket divider device of the present invention is illustrated generally at 10. The wastebasket divider 10 consists of a divider wall 11 and base member 12. The divider wall 11 is a flat, planar member of rectangular shape in the preferred embodiment which is positioned vertically within a wastebasket during normal use. Alternatively, the divider wall 11 could be tapered so as to be smaller in width at its bottom end and able to fit within similarly-shaped tapered wastebaskets. The base member 12 is a flat, planar member which is positioned horizontally against the bottom of the wastebasket 13.
FIG. 2 illustrates the wastebasket divider device 10 in its operative position within a conventional wastebasket or trash receptacle 13. The wastebasket 13 may be of a variety of shapes and sizes, but is rectangular in shape in the preferred embodiment. The wastebasket 13 has four side walls 14 and a bottom wall 15. In the preferred embodiment, the wastebasket 13 is open at its upper end, so as to allow for quick deposit of the trash materials therein. It is to be understood, however, that the wastebasket 13 could also be provided with a suitable, removable cover (not shown). As illustrated in FIG. 2, the base member 12 is positioned against the bottom wall 15 of the wastebasket. The base member 12 is preferably sized and configured to correspond to but be slightly smaller than the dimensions of the wastebasket's bottom wall 15. The wastebasket apparatus 10 is retained within the wastebasket 13 at all times, including when the wastebasket 13 is being emptied of its contents. However, if it is desired to remove the wastebasket divider apparatus 10 from the wastebasket 13 for purposes such as cleaning, such removal is possible by grasping the divider wall 11 and lifting upwardly so as to withdraw the wastebasket divider apparatus 10.
In its normal, operative position within the wastebasket 13, the divider wall 11 is in an upright position which is perpendicular to the base member 12. This position is illustrated by the solid lines in FIG. 2. The divider wall 11 is sized and configured to be slightly smaller than the cross-sectional dimension of the wastebasket 13. In the preferred embodiment, the divider wall 11 is parallel to the narrow side walls 14 of the wastebasket 13. The divider wall 11 thus forms two, completely separate compartments 16 and 17. The compartments 16, 17 are defined by the divider wall 11 and the wastebasket side walls 14.
The compartment 16 is designated for the receipt of a certain type of trash materials, e.g., recyclable paper. The compartment 17 is designated for another type of trash materials, e.g., non-reusable trash materials. It is to be understood that the compartments 16, 17 could be designated for a wide variety of different materials. In the preferred embodiment, the two sides of the divider wall 11 have appropriate labels to remind the user of the type of trash materials to be deposited in the compartment 16. An example of such labels would be a "Recyclable" label on the left side of the divider wall 11 and "Non-recyclable" label on the right side of the divider wall 11, as viewed in FIG. 2.
It is to be understood that the divider wall 11 could be of other configurations in order to divide the wastebasket 13 into more than two compartments. For example, it is within the scope of the invention for the divider wall 11 to consist of two perpendicular wall members (not shown) in a cross configuration, with one wall member being parallel to the length of the wastebasket and another, perpendicular wall member being transverse to the longitudinal access of the wastebasket. This design would allow for separation of the wastebasket 13 into four compartments.
The divider wall 11 and base member 12 are separate pieces which are attached to each other by suitable interconnection means 17. Proximate the bottom end of the divider wall 11 are a pair of bracket members 20. The bracket members 20 are L-shaped, each having a pair of perpendicular legs, an upright leg and a horizontal leg. The horizontal leg or flange 19 extends slightly below the bottom edge of the divider wall 11 so as to define a slot 18. The base member 12 is inserted through the slot 18, with the width of the slot 18 being slightly larger than the thickness of the base member 12 to allow for a slidable interconnection. In the preferred embodiment, the brackets are provided with reinforcement members 21. As shown in the drawings, the brackets 20 maintain the divider wall 11 in its upright position during normal use.
In the preferred embodiment, the divider wall 11 and bracket 20 are made of a suitable molded plastic material. The brackets 20 are of unitary construction with the divider wall 11. The base member 12 is also of a suitable molded plastic material in the preferred embodiment.
A novel feature of the present invention is the ease with which the size of the compartments 16, 17 can be adjusted. This is accomplished by simply moving the divider wall 11 with respect to the stationary base member 12. If, for example, the user needs to deposit a substantial amount of trash materials within the recyclable compartment 16, the divider wall 11 can be moved to the right as viewed in FIG. 2 so as to provide sufficient space for the recyclable materials.
The dashed lines in FIG. 2 illustrate the positions in which the divider wall 11 is placed when the wastebasket 13 is being emptied into a suitable trash receiver receptacle (not shown). If, for example, the recyclable compartment 16 is being emptied, the housekeeping personnel moves the divider wall 11 to the right as viewed in FIG. 2 so that the upper end of the divider wall 11 is proximate or touching the upper end of the side wall 14. This allows the compartment 16 to be emptied without interference from trash materials in the other compartment 17, because the compartment 17 is closed off by the divider wall 11. When the compartment 17 is being emptied, the upper end of the divider wall 11 is moved to the left and a similar process is employed. In the preferred embodiment, the divider wall 28 is made of a suitable material such as plastic which allows for sufficient flexing of the divider wall 28 to accommodate this emptying procedure. This allows the housekeeping personnel to quickly empty the various compartments 16, 17 of the wastebasket 13, without the necessity of having to sort through the trash materials and without the various types of trash materials becoming intermingled.
In operation of the first embodiment of the invention, the wastebasket divider apparatus 10 is positioned within the wastebasket 13 so as to form two compartments 16, 17. The user deposits the appropriate types of waste materials in the designated compartments 16, 17. When adjustment of the compartment sizes is desired, the divider wall 11 is slid relative to the stationary base member 12 by means of the slot 18. When the compartments 16, 17 are emptied, the divider wall 11 is moved so as to close off the compartment 16, 17 which is not being emptied.
A second embodiment of the present invention is illustrated generally at 22 in FIG. 4. The wastebasket apparatus 22 includes a trash receptacle framework 23, the framework 23 having a pair of transverse side walls 24, a pair of longitudinal side walls 25, and a bottom wall 26, thereby forming an enclosure. Proximate the bottom end of the longitudinal side walls 25 are a pair of longitudinal slots or grooves 27 which are formed within the side walls 25. Positioned within the wastebasket framework 23 is a divider wall 28. In the preferred embodiment, the divider wall 28 is planar and extends across the narrower dimension of the wastebasket framework 23, i.e., parallel to the transverse side walls 24.
Proximate the bottom end of the divider wall 28 are a pair of opposite pins 29 which extend outwardly from the side edges of the divider wall 28. The grooves 27 accommodate the pins 29, thereby providing adjustment means for moving the divider wall 28 so as to adjust the size of the compartments 30, 31 formed by the divider wall.
Another feature of the second embodiment 22 is a suitable support means which serves to maintain the divider wall 28 in an upright position during normal use. In the preferred embodiment, the support means comprises bracket members 32 proximate the bottom end of the divider wall 28.
In operation of the second embodiment illustrated in FIG. 4, the wastebasket framework 23 and divider wall 28 form two compartments 30, 31 for the deposit of different types of trash materials. When the size of the compartments 30, 31 is to be adjusted, the divider wall 28 is moved by the user by means of the pins 29 within the grooves 27. Movement of the divider wall 28 to close off one compartment facilitates emptying of the compartments 30, 31 as described above with the first embodiment.
A third embodiment of the present invention is illustrated generally at 33 in FIG. 5. The wastebasket apparatus 33 includes a framework 34 which forms an enclosure defined by transverse side walls 35, longitudinal side walls 36, and a bottom wall 37. Positioned within the framework 34 is a divider wall 38 similar to the divider wall 28 described in conjunction with FIG. 4. Proximate the bottom end of the divider wall 38 are a pair of pins 39 which extend outwardly from the side edges of the divider wall 38.
Proximate the bottom end of each longitudinal side wall 36 are a plurality of holes or indentations 40 formed therein. The holes 40 are sized and configured to accommodate the pins 39. The pins 39 can be withdrawn and snapped into place from the indentations 40 so as to allow adjustment and movement of the divider wall 38 as desired. This embodiment of the invention also includes suitable support means to maintain the divider wall 38 in an upright position during normal use. In the preferred embodiment, the support means comprises a pair of clips 41. The clips 41 serve to interconnect the upper end of the wastebasket side walls 36 to the upper end of the divider wall 38.
In operation of the third embodiment illustrated in FIG. 5, adjustment of the sizes of the compartments 42, 43 is accomplished by removing the clips 41 and moving the pins 39 into a different pair of oppositely disposed holes 40. When emptying is desired, the clips 41 are removed so as to enable movement of the divider wall 38 to close off one compartment while the other compartment is being emptied. After emptying, the clips 41 are replaced so as to maintain the divider wall in its normal, upright position.
Although the present invention has been described with reference to three particular embodiments, it should be understood that those skilled in the art may make many other modifications without departing from the spirit and scope of the invention as described by the appended claims. For example, it is to be understood that the present invention could be redesigned so as to fit within odd-shaped or round wastebaskets by varying the size of the various components. | An apparatus (10) for dividing a wastebasket (13) into multiple compartments (16, 17) is disclosed. The wastebasket divider apparatus (10) includes a base member (12) interconnected to a vertical divider wall (11). The position of the divider wall (11) is adjustable by means of a slot (18) formed by flanges (19). Also disclosed are alternative embodiments of the wastebasket apparatus (22, 33) in which the divider wall (28, 38) is provided with pins (29, 39) which correspond with either a pair of grooves (27) or a plurality of indentations (40) formed with the side walls (25, 35) so as to allow for adjustment of the divider wall (28) (38) within the wastebasket framework (23, 24). | 8 |
[0001] This application claims priority to U.S. Provisional Patent Application No. 60/842,376 filed Sep. 6, 2007, the entire disclosure of which is incorporated herein by reference.
[0002] This application includes material which is subject to copyright protection. The copyright owner has no objection to the facsimile reproduction by anyone of the patent disclosure, as it appears in the Patent and Trademark Office files or records, but otherwise reserves all copyright rights whatsoever.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0003] FIG. 1 shows an embodiment of swimming device of the invention. The invention allows swimmers to comfortably read text, for example a newspaper, while swimming. Many people who need more exercise could consider swimming; however, many people find swimming to be lacking in mental stimulation. The invention helps solve this problem by providing mental stimulation for swimmers.
[0004] One specific example of the invention allows the swimmer to perform the backstroke while reading a newspaper. The invention includes the use of a device to support the newspaper (or other mentally stimulating material) out of the water and above the swimmer so that the newspaper is able to stay dry and visible for reading by the swimmer. The invention may provide a means to form a waterproof sealed enclosure around the swimmer's reading material.
[0005] The device includes optional use of a floatation devices which assist swimmers who may not be able to comfortably stay afloat while simultaneously swimming and reading.
[0006] The device includes optional methods of: (1) comfortably turning the page with mechanical devices; (2) preventing water from splashing into the swimmer's eyes, nose, and mouth; (3) preventing water from splashing onto the newspaper; (4) providing the swimmer with advance warnings of obstructions in the swimmer's path such as the end of the lane; (5) providing warnings and deterrents from all dangers including but not limited to: sharks, whales; coral, sea nettles, jelly fish; (6) providing notifications pertaining to the swimmer's medical conditions including but not limited to: heart rate, pulse, calories burned; (7) providing notifications to medical staff; (8) providing communications between fellow swimmers including but not limited to attached waterproof cell phone or walkie talkie; (9) providing protection against chlorine (or other chemicals or elements) having contact with the swimmer's hair including but not limited to water shields attached to the apparatus; (10) providing warnings of other conditions of all kinds; (11) using various technologies to provide information to the swimmer including but not limited to depth detection, radar, sonar, global positioning system (GPS).
[0007] Another permutation of the invention is waterproof goggles or glasses which have the ability to function as a computer monitor of graphic user interface (GUI) so that text can be displayed in conjunction with a computer. The computer can transfer the text to the waterproof monitor (for example inside goggles) via any number of wired or wireless technologies including but not limited to WI-FI, Bluetooth, etc.
[0008] With the invention, the swimmer is able to swim for long distances very comfortably while reading text such as a newspaper or book without worrying about hitting the wall at the end of the lap lane or hitting another swimmer.
[0009] The invention includes the options of various protections against the swimmer banging her head into the wall at the end of the swimming pool's lap lane, for example.
[0010] The invention includes options of communications between fellow swimmers using this device and communications to others, including but not limited to communications via waterproof cell phone; walkie talkie, etc.
[0011] The invention includes the option of various dynamic adjustments that can be made while swimming so that, for example, the swimmer can make major and minor modifications for comfort, safety, and creature features which allow, for example, long distance swimming.
[0012] This device includes options for a myriad of other interactive entertainment devices which can be used while swimming, including but not limited to electronic interactive games which can be played while swimming between various players including other swimmers.
[0013] An optional computer network connection may be employed while swimming including but not limited to an optional computer network and/or computer devices optionally with remote control devices and optional other interactive digital controls for a myriad of functions (eg: music controls, newspaper page turning, other sensory device controls).
[0014] The invention may optionally include design elements which physically prevent, block or deflect water splashes away from the user's eyes and nose and mouth and newspaper, etc.
[0015] The invention may include waterproof goggles with video for reading.
[0016] The user may optionally use an electronic or computerized reading device.
[0017] The invention may assist the user by providing some floatation.
[0018] The invention may optionally include the ability to electronically sense (via any of various means including but not limited to sonar, radar, laser, photo images, etc.) the end of swimming pool's lane or other obstructions in the path of the swimmer.
[0019] The invention may optionally include page turning devices to facilitate the user's ability to read without interruption.
[0020] The invention may optionally include items to protect the swimmer's body and head from impact.
[0021] The invention may optionally include providing warning to the user of various dangers and providing protection from various dangers including but not limited to: shark deterrents, coral; sea nettles; jelly fish.
[0022] The invention may optionally include providing feedback and warnings to the user about the user's medical conditions including but not limited to heart rate, pulse, data pertaining to exercise such as calories burned, duration of exercise, distance traveled, etc and may optionally provide notifications to medical staff.
[0023] The invention may optionally provide communications between fellow swimmers using this device. For example, communications via waterproof cell phone or walkie talkie, etc. may be provided.
[0024] The device may optionally provide hair protection from chlorine.
[0025] One embodiment of the invention is in the form of an attachment for a swimmer's own personal flotation device, such as a life vest (for example a water skiing floatation vest which is commonly available). This embodiment provides one or more devices to be added or attached as attachments to the flotation device which provide all of the features described herein, including but not limited to flotation device attachments which optionally allow the user to attach a book or newspaper to the flotation device so that it is held up in a position for reading by the user; a reading light. Any suitable attachment means, such as a clip, may be used. A warning system provides data to the user and may assist in providing various protections to the user from dangers (for example: end of lap lane; presence of sharks; presence of jelly fish; presence of sea urchins; etc). One embodiment provides a personal flotation device in combination with one or more of the attachments described herein.
[0026] The swimming device may include a means to add resistance to the user's exercise, including but not limited to: stretchable materials which assist with exercise by providing resistance (such as surgical tubing); paddles which provide resistance in the water; paddles and other physical objects attached by stretchable materials (such as surgical tubing) to the flotation device or to the swimmer's body or to the swimmer's clothing or the swimmer's water shoes.
[0027] While the invention has been particularly shown and described with reference to a preferred embodiment 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. | Disclosed is a swimming device which allows a swimmer to read while swimming. A support structure is configured to support reading material in the form of a book, newspaper, or electronic reading device. An attachment device is operatively connected to the support structure and rigidly connects the support structure to the swimmer's body. | 0 |
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. Provisional Patent Application No. 60/182,008, filed on Feb. 11, 2000.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH
[0002] Not Applicable.
FIELD OF THE INVENTION
[0003] The invention relates generally to infant equipment and, more particularly, to infant beds for coupling to an adult bed.
BACKGROUND OF THE INVENTION
[0004] It is well known that there are advantages to having a newborn sleep in proximity to its mother. For example, when the infant is close by, a mother can easily nurse the infant as well as take care of other needs. Close proximity is also a significant benefit for mothers who have undergone a Cesarean section. In addition, research has shown that newborns rely on proximity to their mothers to regulate body heat, breathing, and cardiac rhythms.
[0005] While there have been attempts to provide proximity and convenience to a mother and her infant, known devices, such as bassinets, do not provide the level of closeness that is desirable for many new mothers. Further, conventional devices that attach to a bed can be cumbersome and render it difficult for a mother to get on and off the bed.
[0006] It would therefore, be desirable to provide an infant bed that is slidably engageable to a bed frame for allowing an adult to be close to an infant to easily get on and off the adult bed.
SUMMARY OF THE INVENTION
[0007] The present invention provides an infant bed that is positionable alongside an adult bed to which the infant bed is secured. Although the invention is primarily shown and described with reference to a hospital-type bed, it is understood that the infant bed can be coupled to a variety of beds having a frame that can support the infant bed alongside thereof.
[0008] In one aspect of the invention, an infant bed has a top portion and a bottom portion, which can be secured to an adult bed frame. Barriers upwardly extend from the top portion to form an interior region for confining an infant. A coupling mechanism, such as mounting rods extending from the bottom portion of the infant bed, secures the infant bed to the adult bed. In one embodiment, the mounting rods are received by corresponding structural members rigidly extending from the frame of the adult bed. The infant bed further includes a slidable bracket mechanism coupled to the bottom portion of the infant bed for allowing the infant bed to be moved along a length of the adult bed.
[0009] In a further aspect of the invention, a method for maintaining proximity between an infant and an adult includes placing a baby into an infant bed that is movable alongside a length of an adult bed. The infant bed is movable between first and second positions that provide closeness to the infant and facilitate egress from the adult/infant bed assembly. In one embodiment, a coupling mechanism secures a bottom portion of the infant bed to the adult bed and a slidable bracket mechanism enables longitudinal movement of the infant bed with respect to the adult bed.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] The invention will be more fully understood from the following detailed description taken in conjunction with the accompanying drawings, in which:
[0011] [0011]FIG. 1 is a pictorial representation of an infant bed that is movable alongside an adult bed in accordance with the present invention;
[0012] [0012]FIG. 2 is a perspective view showing further details of the infant bed of FIG. 1;
[0013] [0013]FIG. 3 is a perspective view of a mechanism for engaging the infant bed of FIG. 1 to a hospital bed;
[0014] [0014]FIG. 4 is a bottom perspective view of the infant bed of FIG. 1;
[0015] [0015]FIG. 5 is a perspective view of an exemplary sliding bracket mechanism that forms a part of the infant bed of FIG. 1;
[0016] [0016]FIG. 6 is a cross-sectional view of a further embodiment of an infant bed in accordance with the present invention; and
[0017] [0017]FIG. 7 is a top view of a portion of the infant bed of FIG. 6.
DETAILED DESCRIPTION OF THE INVENTION
[0018] [0018]FIG. 1 shows an exemplary embodiment of an infant bed 100 in accordance with the present invention. The infant bed can be secured to an adult bed and adjusted to a desired position along the length of a bed as indicated by arrow 101 . Thus, an adult can move the infant bed 100 to facilitate getting on and off the bed, while maintaining a desired level of proximity with a newborn in the infant bed.
[0019] The infant bed 100 includes a flat bottom 102 from which four barriers 104 upwardly extend to confine an infant within the interior. It is understood that the barriers can comprise a variety of configurations that are suitable to keep an infant within the infant bed. Exemplary barriers include solid walls, railed fences and slotted barricades. It is further understood that the infant bed interior can have different geometric configurations including square, rectangular, circular, ovular and polygonal.
[0020] As shown in FIG. 2, the infant bed 100 is engageable to a bed frame 10 , such as the frame of a hospital bed. The infant bed 100 is well-suited for use with a wide variety of bed frames generally having frame members for supporting a mattress and/or boxspring. The bed frame 10 can include a first pair of opposed frame members 12 , 14 for supporting a mattress along its length and a second pair of opposed frame members 16 ,(not shown) located at the head and foot of the bed frame for supporting the mattress along its width. The bed frame can further include a flat support member 20 that provides a flat surface adapted to support the underside of the mattress.
[0021] [0021]FIG. 3 shows an exemplary mechanism for coupling the infant bed to the hosptial bed frame. The coupling mechanism includes first and second mounting rods 106 , 108 rigidly extending from a base of the infant bed. In one embodiment, the rods 106 , 108 are fixedly coupled to a bottom portion of the infant bed base, as described below, to allow the infant bed to move along a length of the mother's bed. The rods 106 , 108 are insertable within corresponding first and second structural members 110 , 112 that are securable to the bed frame. The rods can be secured to the structural members using suitable permanent and removable devices including, nuts, bolts, rivets, interference fits, adhesives, welds, lock nuts and pins. In an illustrative embodiment, removable locking pins are used to secure the rods to the structural members. The pins prevent the infant bed from unintentional disengagement from the bed frame while allowing a user to remove the infant bed when desired.
[0022] The structural members 110 , 112 can be affixed to the bed frame using nut, bolt and washer assemblies to secure the members to the frame. In one embodiment, cross members 113 affixed to ends of the structural members are bolted to the bed frame, such as to the support member 20 , in at least one location 115 .
[0023] The position of the infant bed 100 can be adjusted along the length of the hospital bed as shown by the bi-directional arrow 101 shown in FIG. 1. In one embodiment, the infant bed is slidable with respect to the rods 106 , 108 , which are secured to a bottom portion of the infant bed base. A variety of suitable mechanisms can be used to allow the infant bed 100 to slide along the length of the bed. Exemplary mechanisms include brackets, rods, and channels.
[0024] [0024]FIG. 4 (bottom view) shows an exemplary arrangement for allowing the infant bed to slide to a desired location alongside the adult sized bed. The base 102 of the infant bed includes a top portion 150 that is movable with respect to a bottom portion 152 to which the rods 106 , 108 are secured. The base further includes sliding bracket mechanisms 154 a,b that allow the base top portion 150 to move while the base bottom portion 152 remains in a fixed position relative to the bed frame.
[0025] In one embodiment, opposed first and second base extension members 156 a,b rigidly extend from bottom edges of the flat bottom of the infant bed. A first inner base member 158 a is secured to the bottom portion 152 of the base in spaced opposition to the first base extension member 156 a , such the outer and inner base members form a channel. The bottom portion of the base, which is fixed relative to the bed frame, includes opposed structural members 160 a,b to which the outwardly extending mounting rods 106 , 108 are secured. In one embodiment, the first inner base member 158 a is connected to the structural members of the base bottom portion. Similarly, the second inner base member 158 b , which is affixed to the structural members 160 , is disposed in spaced opposition to the second base extension member 156 b so as to form a channel. The bottom portion of the base can further include cross members 162 a,b for increasing the overall structural integrity of the device.
[0026] The first bracket mechanism 154 a is adapted for operating in the first channel formed by the first base extension member and the first inner base member. The second bracket mechanism 154 b is adapted for operating in the second channel formed by second base extension member and the second inner base member. Each bracket mechanism includes first and second track-rail/slider assemblies for coupling to the base extension members. An exemplary track-rail sliding bracket mechanism is identified as Part No. S28T-120/540, which is shown in FIG. 5, available from Rollon Corporation of New Jersey and web site www.rollon.com.
[0027] The track-rail of the first bracket mechanism 154 a is secured to an inner surface of the first base extension member (top portion of base) 156 a and the corresponding slider is secured to a corresponding surface of the inner base member (bottom portion of base) 158 a . Similarly, the track-rail and slider of the second bracket mechanism 154 b are coupled to the respective second base extension member 156 b and the second inner base member 158 b . The sliders are easily displaceable within the track by means of a ball bearing cage. The slidable bracket mechanisms are disposed within the first and second channels to allow the top portion of the base to slide with respect to the bottom portion of the base. This arrangement allows the infant bed to be slidably positioned alongside the bedframe.
[0028] FIGS. 6 - 7 show an alternative embodiment of an infant bed 200 that is movable alongside an adult bed (not shown) in accordance with the present invention. The infant bed includes a top portion 202 having a area for containing an infant and a bottom portion 204 . In one embodiment, the bottom portion 204 of the infant bed includes opposed first and second members 204 a,b secured to the top portion 202 .
[0029] The first and second members 204 of the infant bed bottom portion are secured to respective first and second slidable bracket mechanisms 206 a,b , which are also secured to a coupling mechanism, shown as a pair of rigid mounting rods 208 a,b . The mounting rods 208 can be secured to structural members (not shown) extending from the adult bed. The opposed first and second slidable bracket mechanisms 204 a,b enable the infant bed to move alongside the adult bed.
[0030] In another feature of the invention, the base includes a locking mechanism for securing the infant bed in position along its length of travel. The locking mechanism allows a user to affix the infant bed in a position after it has been moved to a desired position alongside the bed. Exemplary locking mechanisms include pins, bolts, interlocking surface features, and interference devices.
[0031] It is understood that various modifications and substitutions can be made to the embodiments described herein without departing from the present invention. For example, the type and number of devices corresponding to the slidable bracket mechanisms can be readily modified by one of ordinary skill in the art. In addition, a wide variety of devices known to one of ordinary skill in the art can be used for the coupling mechanism securing the infant bed to a bed frame. It is understood that further changes from the particular embodiments shown and described herein will be readily apparent.
[0032] One skilled in the art will appreciate further features and advantages of the invention based on the above-described embodiments. Accordingly, the invention is not to be limited by what has been particularly shown and described, except as indicated by the appended claims. All publications and references cited herein are expressly incorporated herein by reference in their entirety. | An infant bed is slidably attachable to a bed frame such that the infant bed can be moved along a length of the bed frame. The infant bed can be readily moved in relation to the bed to maintain infant/adult closeness and facilitate adult ingress/egress from the adult bed. | 0 |
TECHNICAL FIELD
[0001] Embodiments of the subject matter described herein relate generally to integrated circuits and methods for fabricating the same. More particularly, the subject matter relates to integrated circuits and methods for fabricating integrated circuits having a replacement gate structure.
BACKGROUND
[0002] The integration of hundreds of millions of circuit elements, such as transistors, on a single integrated circuit necessitates further dramatic scaling down or micro-miniaturization of the physical dimensions of circuit elements, including interconnection structures. Micro-miniaturization has engendered a dramatic increase in transistor engineering complexity, such as the inclusion of lightly doped drain structures, multiple implants for source/drain regions, silicidation of gates and source/drains, and multiple sidewall spacers, for example.
[0003] The drive for high performance requires high speed operation of microelectronic components requiring high drive currents in addition to low leakage, i.e., low off-state current, to reduce power consumption. Typically, the structural and doping parameters tending to provide a desired increase in drive current adversely impact leakage current.
[0004] Metal gate electrodes have evolved for improving the drive current by reducing polysilicon depletion. However, simply replacing polysilicon gate electrodes with metal gate electrodes may engender issues in forming the metal gate electrode prior to high temperature annealing to activate the source/drain implants, as at a temperature in excess of 900° C. Such fabrication techniques may degrade the metal gate electrode or cause interaction with the gate dielectric, thereby adversely impacting transistor performance.
[0005] Replacement gate techniques have been developed to address problems attendant upon substituting metal gate electrodes for polysilicon gate electrodes. For example, a polysilicon gate is used during initial processing until high temperature annealing to activate source/drain implants has been implemented. Subsequently, the polysilicon is removed and replaced with a metal gate.
[0006] Additional issues arise with lateral scaling, such as the formation of contacts. For example, once the contacted gate pitch gets to about 70 nanometers (nm) or below, there is not enough room to land a contact between the gate lines and still maintain reliable electrical isolation properties between the gate line and the contact. Various self-aligned contact (SAC) methodologies have been developed to address this problem. To realize a SAC compatible with replacement gate techniques, two nitride liners are required to be present in the gate structure for the purpose of blocking ionic diffusion from an interlayer dielectric (ILD) oxide material layer, which is typically present adjacent to the gates, during chemical mechanical planarization (CMP) steps, which are often used during the replacement gate forming process. Conformal atomic layer deposition (ALD) methods are currently used to deposit these nitride liners. However, ALD reduces the space available for SAC opening between gates. As such, these current methodologies do not provide enough space between gates to allow for SAC formation therebetween.
[0007] A need therefore exists for an improved methodology enabling the fabrication of semiconductor devices including integrating both metal replacement gates and self-aligned contacts for small-scale architectures. Further, there exists a need for an improved methodology enabling the fabrication of semiconductor devices that provide more space for contacts in devices with a small gate pitch. Still further, other desirable features and characteristics of the present invention will become apparent from the subsequent detailed description of the invention and the appended claims, taken in conjunction with the accompanying drawings, the brief summary, and this background of the invention.
BRIEF SUMMARY
[0008] Methods of fabricating integrated circuits are provided herein. In an exemplary embodiment, a method for fabricating an integrated circuit includes forming a temporary gate structure on a semiconductor substrate. The temporary gate structure includes a temporary gate material disposed between two spacer structures. The method further includes forming a first directional silicon nitride liner overlying the temporary gate structure and the semiconductor substrate, etching the first directional silicon nitride liner overlying the temporary gate structure and the temporary gate material to form a trench between the spacer structures, while leaving the directional silicon nitride liner overlying the semiconductor substrate in place, and forming a replacement metal gate structure in the trench. The replacement metal gate structure includes a work function material and a conductive material. Still further, the method includes forming a contact adjacent to the replacement metal gate structure.
[0009] In another exemplary embodiment, a method for fabricating an integrated circuit includes forming a temporary gate structure on a semiconductor substrate, the temporary gate structure including a temporary gate material disposed between two spacer structures, forming a first directional silicon nitride liner overlying the temporary gate structure and the semiconductor substrate, and etching the first directional silicon nitride liner overlying the temporary gate structure and the temporary gate material to form a trench between the spacer structures, while leaving the directional silicon nitride liner overlying the semiconductor substrate in place. The method further includes forming a replacement metal gate structure in the trench, the replacement metal gate structure including a work function material and a conductive material, etching the first directional silicon nitride liner overlying the semiconductor substrate after forming the replacement metal gate structure, and forming a silicide region adjacent the gate structure. Still further, the method includes forming a second directional silicon nitride liner overlying the replacement metal gate structure and the silicide region and forming a contact to the silicide region by etching at least a portion of the directional silicon nitride liner overlying the silicide region.
[0010] In yet another exemplary embodiment, an integrated circuit includes a replacement metal gate structure overlying a semiconductor substrate and a silicide region overlying the semiconductor substrate and positioned adjacent the replacement metal gate structure. The integrated circuit further includes a directional silicon nitride liner overlying the replacement metal gate structure and a contact plug in electrical communication with the silicide region.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] The disclosed embodiments will hereinafter be described in conjunction with the following drawing figures, wherein like numerals denote like elements, and wherein:
[0012] FIGS. 1-18 are partial cross-section views of an integrated circuit illustrating methods for fabricating an integrated circuit having a replacement gate structure and self-aligned contacts in accordance with one embodiment of the present disclosure.
DETAILED DESCRIPTION
[0013] The following detailed description is merely illustrative in nature and is not intended to limit the embodiments of the subject matter or the application and uses of such embodiments. As used herein, the word “exemplary” means “serving as an example, instance, or illustration.” Any implementation described herein as exemplary is not necessarily to be construed as preferred or advantageous over other implementations. Furthermore, there is no intention to be bound by any expressed or implied theory presented in the preceding technical field, background, brief summary or the following detailed description.
[0014] For the sake of brevity, conventional techniques related to semiconductor device fabrication may not be described in detail herein. Moreover, the various tasks and process steps described herein may be incorporated into a more comprehensive procedure or process having additional steps or functionality not described in detail herein. In particular, various steps in the manufacture of semiconductor-based integrated circuits are well known and so, in the interest of brevity, many conventional steps will only be mentioned briefly herein or will be omitted entirely without providing the well-known process details.
[0015] The techniques and technologies described herein may be utilized to fabricate MOS integrated circuit devices, including NMOS integrated circuit devices, PMOS integrated circuit devices, and CMOS integrated circuit devices. In particular, the process steps described here can be utilized in conjunction with any semiconductor device fabrication process that forms gate structures for integrated circuits, including both planar and non-planar integrated circuits. Although the term “MOS device” properly refers to a device having a metal gate electrode and an oxide gate insulator, that term will be used throughout to refer to any semiconductor device that includes a conductive gate electrode (whether metal or other conductive material) that is positioned over a gate insulator (whether oxide or other insulator) which, in turn, is positioned over a semiconductor substrate.
[0016] With reference to FIG. 1 , in one embodiment, depicted is a cross-sectional view of a partially-formed integrated circuit (IC) prior to forming the replacement gate structure therein. In particular, FIG. 1 depicts the fabrication state of a semiconductor device structure after formation of “dummy” gate structures 103 overlying a layer of semiconductor material 101 , and a thin layer of dummy oxide material 102 , such as silicon oxide, which is provided as a gate insulator. FIG. 1 represents a view from a cross-section taken through the major longitudinal axes of the dummy gate structures 103 . Although two dummy gate structures 103 are shown in FIG. 1 (and the other figures), the device structure could include any number, including only one. The device structure is formed using well known techniques and process steps (e.g., techniques and steps related to doping, photolithography and patterning, etching, material growth, material deposition, surface planarization, and the like) that will not be described in detail here.
[0017] The semiconductor material 101 is preferably a silicon material as typically used in the semiconductor industry, e.g., relatively pure silicon as well as silicon admixed with other elements such as germanium, carbon, and the like. Alternatively, the semiconductor material 101 can be germanium, gallium arsenide, or the like. The semiconductor material 101 can be either N-type or P-type, but is typically P-type, with wells of the appropriate type formed therein. The semiconductor material 101 may be provided as a bulk semiconductor substrate, or it could be provided on a silicon-on-insulator (SOI) substrate, which includes a support substrate, an insulator layer on the support substrate, and a layer of semiconductor material on the insulator layer.
[0018] Overlying each dummy gate structure 103 is a sacrificial hard mask cap 104 . This hard mask cap 104 , which may be formed from a nitride, a silicide, or other material, is used as part of an etch mask during the formation of the dummy gate structures 103 .
[0019] The material used for the gate insulator layer 102 can be a layer of thermally grown silicon oxide as noted above, such as silicon dioxide. In alternative embodiments, the layer 102 can be a deposited insulator such as a silicon oxide, silicon nitride, any kind of high-k oxide such as hafnium oxides, or the like. Deposited insulators can be deposited, for example, by chemical vapor deposition (CVD), atomic layer deposition (ALD), low pressure chemical vapor deposition (LPCVD), or plasma enhanced chemical vapor deposition (PECVD). The gate insulator material preferably has a thickness of about 1-10 nm, although the actual thickness can be determined based on the application of the transistor in the circuit being implemented. The material for the dummy gate structure 103 is formed overlying the gate insulator material. In accordance with certain embodiments, the material used for the dummy gate structure 103 is polycrystalline silicon, although other replaceable materials could be used instead of polycrystalline silicon. The layer of polycrystalline silicon is preferably deposited, e.g., using LPCVD by the hydrogen reduction of silane. Typically, the polycrystalline silicon will have a thickness within the range of about 50-100 nm. Thereafter, the polycrystalline silicon is etched using the hard mask caps 104 as an appropriate etch mask. In an embodiment, reactive ion etching (RIE) may be employed as a suitable anisotropic etch technique.
[0020] With reference now to FIG. 2 , spacer structures 105 are fabricated on either side of the dummy gate 103 and hard mask cap 104 in a conventional manner. In this regard, the spacers 105 can be created by conformally depositing a dielectric material over the wafer, where the dielectric material is an appropriate insulator, such as silicon nitride. The dielectric spacer material can be deposited in a known manner by, for example, atomic layer deposition (ALD), CVD, LPCVD, semi-atmospheric chemical vapor deposition (SACVD), or PECVD. The layer of dielectric spacer material is deposited to a thickness so that, after anisotropic etching, the spacers 105 formed from the layer have a thickness that is appropriate for any subsequent process steps. In typical implementations, the layer of dielectric spacer material is deposited to a thickness of about 5-50 nm. The process continues, in accordance with an exemplary embodiment, with anisotropic etching of the layer of dielectric spacer material to form the spacers 105 , as illustrated in FIG. 2 . The layer of dielectric spacer material can be etched by, for example, reactive ion etching (RIE) using a suitable etching chemistry.
[0021] The spacers 105 can be used to protect the underlying semiconductor material during ion implantation associated with the formation of source/drain extension implants, halo implants, and/or deep source/drain implants, as is well understood. As such, as disclosed in FIG. 3 , the method continues with the formation of source/drain regions 106 , by conventional processes, such as epitaxially, for example of SiGe and/or SiC, on substrate 101 at opposite sides of each gate 103 , and thereafter appropriately doped.
[0022] With reference now to FIG. 4 , additional spacer structures 107 are fabricated on either side of the spacers 105 in a conventional manner. In this regard, the spacers 107 can be created by conformally depositing a dielectric material over the wafer, where the dielectric material is an appropriate insulator, such as a silicon oxide. The dielectric spacer material can be deposited in a known manner by, for example, atomic layer deposition (ALD), CVD, LPCVD, semi-atmospheric chemical vapor deposition (SACVD), or PECVD. It is noted that this layer will be deposited over the source/drain regions 106 . The layer of dielectric spacer material is deposited to a thickness so that, after anisotropic etching, the spacers 107 formed from the layer have a thickness that is appropriate for any subsequent process steps. In typical implementations, the layer of dielectric spacer material is deposited to a thickness of about 5-50 nm. The process continues, in accordance with an exemplary embodiment, with anisotropic etching of the layer of dielectric spacer material to form the spacers 107 , as illustrated in FIG. 4 . The layer of dielectric spacer material can be etched by, for example, reactive ion etching (RIE) using a suitable etching chemistry.
[0023] With reference now to FIG. 5 , source and drain implants are performed in the region 108 . These implants are substantially blocked by the sidewall spacers 107 , which as noted above were provided over the source/drain regions 106 . Accordingly, the sidewall spacers 107 act as a boundary that guides the dopants into source and drain regions 106 of the substrate. The implants are spaced apart from the dummy gates by the width of the spacers 107 . By way of example, a dopant of boron, arsenic or phosphorous or other suitable dopant may be implanted at an energy level of about 3 to 50 KeV to provide dopant to an implant range into silicon of about 200-5000 Angstroms, for example.
[0024] Referring now to FIG. 6 , the outer spacers 107 are removed or pulled back. In one embodiment, removal of the spacers 107 removes any spacer material overlaying the source/drain regions 106 . In one embodiment, removal of the spacers is achieved with an anisotropic or isotropic etch, such as RIE or dry etch. Preferably, the spacer 107 removal etch is highly selective to the nitride spacers 105 to avoid the removal thereof. In one embodiment, the spacer pull-back etch employs a CH 2 F 2 /Ar/O 2 or CHF 3 /Ar/O 2 chemistry, and is performed at a temperature of about 1-150° C. and a pressure of about 5-45 mTorr. Under such conditions, SiN-to-oxide etch selectivity of more than about 10:1 can be obtained. Other etch chemistries or techniques of pulling back the spacers 107 are also useful.
[0025] Thereafter, with reference to FIG. 7 , a direction nitride liner is deposited over the gate structures ( 109 a ) and over the source/drain regions ( 109 b ). In one embodiment, the directional nitride liner 109 a / 109 b can be formed using gas cluster ion beam (GCIB) deposition techniques. As is known in the art, GCIB are commonly used for etching, cleaning, smoothing, and forming thin films, such as the directional silicon nitride liner 109 a / 109 b herein. For purposes of this discussion, gas clusters are nano-sized aggregates of materials that are gaseous under conditions of standard temperature and pressure. Such gas clusters may consist of aggregates including a few to several thousand molecules, or more, that are loosely bound together. The gas clusters can be ionized by electron bombardment, which permits the gas clusters to be formed into directed beams of controllable energy. Such cluster ions each typically carry positive charges given by the product of the magnitude of the electron charge and an integer greater than or equal to one that represents the charge state of the cluster ion. When growing a nitride such as SiN X , a substrate including silicon or a silicon-containing material may be irradiated by a GCIB formed from a material source having a nitrogen-containing gas. For example, the material source may include N 2 . In another example, the material source may include NO, NO 2 , N 2 O, or NH 3 , or any combination of two or more thereof.
[0026] In another embodiment, the direction nitride liner 109 a / 109 b can be formed using high density plasma (HDP) deposition techniques. As is known in the art, HDP deposition is a process used to deposit thin films, such as the directional silicon nitride liner 109 a / 109 b herein, from a gas state (vapor) to a solid state on a substrate. Chemical reactions are involved in the process, which occur after creation of a plasma of the reacting gases. The plasma is generally created by RF (AC) frequency or DC discharge between two electrodes, the space between which is filled with the reacting gases. Plasma-deposited silicon nitride is formed from silane and ammonia or nitrogen, and typically includes a percentage of hydrogen as well. In yet another embodiment, plasma enhanced chemical vapor deposition (PECVD) could be employed in a manner than minimizes deposition of the silicon nitride liner on the side wall spacers. For any embodiment, the directional silicon nitride liner 109 a / 109 b is deposited to a thickness of about 2 nm to about 10 nm, for example about 5 nm.
[0027] Continuing with the exemplary method, an interlayer dielectric (ILD) 110 is deposited over the substrate and the gates, as shown in FIG. 8 . The ILD 110 can include silicon dioxide, fluorinated silicon dioxide, low-k dielectrics, such as porous low-k dielectrics, carbon-doped dielectric materials, organic polymers, inorganic polymers, blends of organic/inorganic polymers, and the like. The ILD 110 can be deposited using chemical vapor deposition methods (CVD), spin-on methods, or the like.
[0028] Thereafter, with reference to FIG. 9 , the ILD 110 is polished until the directional silicon nitride liner 109 a overlying the gate structures is reached. In one example, chemical mechanical planarization (CMP) may be employed to reduce the ILD layer 110 . CMP typically requires the substrate to be attached to a carrier, a so-called polishing head, such that the substrate surface to be planarized is exposed and may be placed against a polishing pad. The polishing head and polishing pad are moved relative to each other usually by individually moving the polishing head and the polishing pad. Typically, the head and pad are rotated against each other while the relative motion is controlled to locally achieve a target material removal rate. During the polishing operation, typically a slurry that may include a chemically reactive agent and possibly abrasive particles is supplied to the surface of the polishing pad.
[0029] With reference now to FIG. 10 , the directional nitride liner 109 a, the dummy gate 103 , and the hard mask 104 thereover are removed using a suitable dry etch or wet etch. The dummy gate 103 and the hard mask 104 are removed using an appropriate etchant chemistry that selectively etches the material used for the dummy gate 103 and the hard mask 104 (e.g., polycrystalline silicon/silicon nitride). In one embodiment, etching is performed in two steps, the first to etch the hard mask 104 , and the second to etch the dummy gate 103 . This selective etch has little or no effect on the other exposed device elements, including the spacers 105 . The etchant chemistry, the etching conditions, the duration of the etching process, and other factors can be controlled as needed to ensure that the dummy gate 103 and the hard mask 104 are selectively removed in an efficient and effective manner. This etching forms trenches 111 , as indicated in FIG. 10 .
[0030] FIG. 11 depicts the formation of the replacement gate structures. In one embodiment, formation of the replacement gate structures begins with the deposition of a high-k material layer in the trenches 111 (not specifically illustrated). The high-k material layer can include a Hafnium (Hf) or Zirconium (Zr) oxide, or any other metal oxide with a sufficiently high dielectric constant as is well-known in the art. In an exemplary embodiment, the high-k material layer is HfO 2 . The high-k material layer 106 can be deposited by any technique known in the art that provides for conformal deposition thereof in the trenches 105 . In one embodiment, the high-k material 106 is deposited using atomic layer deposition (ALD).
[0031] Thereafter, one or more workfunction material layers 112 are deposited, patterned, and etched over the high-k layer, as shown in FIG. 11 . Of course, any workfunction material layer may include two or more workfunction materials. The IC may include either n-type or p-type MOS transistors. Where a p-type MOS transistor is desired, any material with a workfunction that is on the p-side of the band-gap, and can be deposited using a process that provides for conformal deposition, for example ALD, may be used for layer 112 . Where an n-type MOS transistor is desired, any material with a workfunction that is on the n-side of the band-gap, and can be deposited using a process that provides for conformal deposition, for example ALD, may be used for layer 112 . Exemplary work function materials include TiN, TaN, TaC, and TiAlN, and combinations thereof.
[0032] Within the workfunction material layer 112 is formed a conductive metal layer 113 which is provided to decrease the line resistance in the replacement gate structure. Typical conductive metals that may be employed for layer 113 include, for example, aluminum, tungsten, or copper, or combinations thereof Along with the workfunction material layer 112 , the conductive metal layer 113 is etched back within the trenches 111 so as to only partially fill the trenches 111 .
[0033] Thereafter, as shown in FIG. 11 , a further process step of depositing a capping layer 114 of, for example, silicon nitride is employed. The capping layer 114 fills the remaining portion of the trenches 111 , thereby covering the layers 112 and 113 exposed therewithin. Silicon nitride, in one embodiment, can be deposited using plasma enhanced chemical vapor deposition (PECVD), although other techniques known in the art can be employed for filling and capping the trenches 111 with silicon nitride. Thereafter, chemical-mechanical planarization (CMP), as is known in the art, can be employed to reduce the height of the structures to a desired thickness.
[0034] Continuing with the exemplary method, FIGS. 12 and 13 illustrate the etching and removal of the ILD layer 110 and the remaining directional silicon nitride liner 109 b, respectively. The ILD layer 110 and the nitride liner 109 b can be etched by, for example, an isotropic etch or alternatively reactive ion etching (RIE) using a suitable etching chemistry. In one embodiment, etching is performed in two steps, the first step for the ILD layer 110 using a chemistry suitable for etching oxides and the second step for the nitride liner 109 b using a different chemistry suitable for etching nitrides.
[0035] With reference now to FIG. 14 , metal silicide regions 115 are formed over the source/drain regions 106 . In one embodiment, a metal layer is formed over the device utilizing a deposition process including, but not limited to, sputtering, evaporation, plating, CVD, atomic layer deposition, or chemical solution deposition. The metal layer may be formed using any metal that is capable of forming a metal silicide when in contact with silicon and subjected to annealing. Suitable metals include, but are not limited to, nickel, cobalt, titanium, tungsten, molybdenum, tantalum, platinum, palladium, copper, and the like. In addition metal alloys may also be used. A capping layer, such as titanium nitride, may be provided over the metal layer to act as an oxygen diffusing barrier during the silicidation anneal. The thickness of the metal layer may range from about 5 nm to about 50 nm, depending on the particular metal chosen. Those of ordinary skill in the art are familiar with thickness ratios required to achieve full silicidation of the silicon material. The semiconductor device is thereafter subjected to an annealing process to convert the material of the silicon layer to a metal silicide 115 . The particular form of silicide may vary depending on the metal selected and the characteristics of the annealing process. The temperature and time parameters of the anneal process may be controlled to form the intended silicide material and phase, as is known to those of ordinary skill in the art. The anneal process may be performed in a rapid thermal processing tool or a furnace, and the anneal time and temperature may vary. For example, the anneal time may range from 0 seconds for a spike anneal to 60 seconds in an RTP tool, while the anneal time in a furnace may range from 10-30 minutes. Temperatures for the anneal process may range from about 300-500° C. Following the completion of the silicide process, a material removal process, such as a wet etch may be performed to remove unreacted portions of the metal layer. For example, a sulfuric acid and H 2 O 2 etch (SPM) followed by treatment with an APM solution including of NH 4 OH, H 2 O 2 , and water may be used to remove the unreacted metal.
[0036] Thereafter, as shown in FIG. 15 , another direction nitride liner is deposited over the gate structures ( 116 a ) and over the source/drain regions ( 116 b ). In one embodiment, the direction nitride liner 116 a / 116 b can be formed using gas cluster ion beam (GCIB) deposition techniques, as discussed above. In another embodiment, the direction nitride liner 116 a / 116 b can be formed using high density plasma (HDP) deposition techniques. In yet another embodiment, plasma enhanced chemical vapor deposition (PECVD) could be employed in a manner than minimizes deposition of the silicon nitride liner on the side wall spacers. For any embodiment, the directional silicon nitride liner 116 a / 116 b is deposited to a thickness of about 10 nm to about 20 nm, for example about 15 nm.
[0037] Continuing with the exemplary method, over the substrate and the gates is deposited another interlayer dielectric (ILD) 117 , as shown in FIG. 16 . The ILD 117 can include silicon dioxide, fluorinated silicon dioxide, low-k dielectrics, such as porous low-k dielectrics, carbon-doped dielectric materials, organic polymers, inorganic polymers, blends of organic/inorganic polymers, and the like. The ILD 117 can be deposited using chemical vapor deposition methods (CVD), spin-on methods, or the like. Thereafter, the ILD 117 is polished until the directional silicon nitride liner 116 a overlying the gate structures is reached. In one example, chemical mechanical planarization (CMP) may be employed to reduce the ILD layer 117 . Thereafter, as shown in FIG. 17 , a blanket ILD layer 118 is deposited over the device. Any of the materials or techniques, as noted above, may be employed for this step.
[0038] Finally, as illustrated in FIG. 18 , a contact plug is formed to connect with the silicide region 115 . For example, in one embodiment, a photolithographic sequence can be performed on the basis of well-established techniques, followed by anisotropic etch techniques and chemistries for forming contact openings in the layers 117 and 118 . The etch process for forming the contact openings may be reliably controlled on the basis of using the silicide 115 as an etch stop layer. Electrical contact in the fabrication of semiconductor devices is realized with the formation of contact plugs 119 , wherein etched openings extending through the interlayer dielectric (ILD) layer 117 and 118 are filled with a conductive material in order to electrically connect to the respective circuit element. The contact plugs 119 are typically formed of a tungsten-based metal, although other metals are possible. As such, as depicted in FIG. 18 , at least a portion of the direction silicon nitride liner overlying the silicide region 116 b is etched to allow for the connection between the contact plug 119 and the silicide region 115 . Further, due to the tapered shape of the contact openings, a small portion of the silicon nitride liner overlying the replacement metal gate 116 a will also be etched to form the contract plug 119 .
[0039] Thereafter, further processing steps can be performed to fabricate the integrated circuit, as are well-known in the art. For example, further processing steps can include the formation of one or more patterned conductive layers across the device, connected with the contacts 119 and one or more via structures, with dielectric layers thereinbetween, among many others. The subject matter disclosed herein is not intended to exclude any subsequent processing steps to form and test the completed IC as are known in the art.
[0040] As such, the subject matter disclosed herein, in one embodiment, includes an integrated circuit fabrication technique for forming a replacement gate structure that has numerous advantages over techniques conventionally employed in the art. For example, the illustrated process flow offers a robust process flow to make a self-aligned contact suitable for use with a replacement metal gate process flow, and that is compatible with various gate structures. The presently described process flow offers a reduced fabrication burden for tight contact pitches with the use of directional silicon nitride deposition as the blocking nitride liner. For example, up to about 20 nm of space can be saved in between gate structures using the methods described herein. As such, this flow will allow for future scalability in replacement gate architectures that employ self-aligned contacts, particularly in architectures having less than or equal to about 64 nm of pitch between gate structures.
[0041] While at least one exemplary embodiment has been presented in the foregoing detailed description of the invention, it should be appreciated that a vast number of variations exist. It should also be appreciated that the exemplary embodiment or exemplary embodiments are only examples, and are not intended to limit the scope, applicability, or configuration of the invention in any way. Rather, the foregoing detailed description will provide those skilled in the art with a convenient road map for implementing an exemplary embodiment of the invention, it being understood that various changes may be made in the function and arrangement of elements described and methods of preparation in an exemplary embodiment without departing from the scope of the invention as set forth in the appended claims and their legal equivalents. | A method for fabricating an integrated circuit includes forming a temporary gate structure on a semiconductor substrate. The temporary gate structure includes a temporary gate material disposed between two spacer structures. The method further includes forming a first directional silicon nitride liner overlying the temporary gate structure and the semiconductor substrate, etching the first directional silicon nitride liner overlying the temporary gate structure and the temporary gate material to form a trench between the spacer structures, while leaving the directional silicon nitride liner overlying the semiconductor substrate in place, and forming a replacement metal gate structure in the trench. An integrated circuit includes a replacement metal gate structure overlying a semiconductor substrate, a silicide region overlying the semiconductor substrate and positioned adjacent the replacement gate structure; a directional silicon nitride liner overlying a portion of the replacement gate structure; and a contact plug in electrical communication with the silicide region. | 7 |
CROSS REFERENCE TO OTHER APPLICATIONS
This application claims the benefit of U.S. Provisional Patent Application No. 60/153,114, filed Sep. 7, 1999.
FIELD OF THE INVENTION
This invention relates to the production of ozone (O 3 ) and decomposition of contaminants, specifically to methods and apparatus for using density differences in fluids combined with a cylindrically configured irradiation apparatus for improved production of ozone from air or oxygen and for decontamination. Ozone is used as a treatment for drinking water, wastewater, and related applications where it interacts with organic impurities to implement disinfection. Decontamination applications include removal of gaseous pollutants such as sulfur dioxide from effluent gas and volatile organic compound decomposition in water, wastewater, air and other gases.
BACKGROUND OF THE INVENTION
Currently there is only one widely used process for the generation of ozone for water treatment and other commercial uses. This process is referred to as “corona discharge” or “silent discharge”. In this process the oxygen or air is introduced to a high voltage environment where the high voltage causes the gas to “corona” at areas of concentrated electric field which leads to break down and arcing between the negative electrode (cathode) and the positive electrode (anode). The products of decomposition of the oxygen include ozone. The corona discharge devices that were first developed have been improved over the years. And now commercially available corona discharge devices can generate a pound of ozone from pure oxygen with as little as 3 kilowatt-hours of energy. Furthermore, the corona discharge process can now convert more than 10 percent of pure oxygen to ozone. Both the energy efficiency and the ozone concentration are critical to the economical production of ozone. In addition to these operating characteristics, ozone generator equipment cost and maintenance are important factors.
Although the corona discharge process has come to be the main method for ozone production, it has its disadvantages and limitations. First of all, relatively large electrode surface areas are required for the corona discharge process. This causes corona discharge reaction chambers to be relatively large and expensive. This large size can also have a significant impact on the space requirements within the user's process facility. Secondly, corona discharge devices require periodic cleaning and replacement of their corona discharge electrodes and insulators in order to minimize system failures. This not only has a labor cost impact, but also has an impact on the floor space needed for access to the system for proper cleaning as well as an impact on the available up time of these systems. Thirdly, corona discharge systems require relatively sophisticated high voltage, high frequency pulsed power supplies to operate. These systems are expensive, complicated and require access to highly qualified technical staff for servicing. And finally, the operating efficiency of the corona discharge device is highly dependent on the availability of low temperature cooling water. This means that in most locations a substantial cost for water chillers must be included in the capital equipment and operating budget for corona discharge systems. In addition, more space, power, and maintenance are required to support the chiller.
Alternative methods for the production of ozone have been reviewed and some have been shown to be viable from the aspect of overall efficiency of production. Steinberg, Beller, and Powell have discussed the advantages of using chemonuclear reactors as an efficient ozone production process. Unfortunately this process may only be cost effective from a capital equipment standpoint for the very largest of water treatment facilities. A number of studies have been made evaluating ozone production rates using either gamma or electron beam radiation. Although these studies have generally shown production efficiencies that equal or exceed corona discharge devices, the capital cost comparisons did not show any economic advantages of these alternatives except for the very largest of systems.
Several patents have been issued for electron beam devices used for the generation of ozone. U.S. Pat. No. 3,883,413 to Douglas-Hamilton (1975) discusses a pulsed discharge electron beam device that generates ozone with the same efficiency that corona discharge systems have today. However this system is not an economical alternative because of its typical ozone concentration of only 0.4%. This is well below the 10 to 15% ozone concentration levels attainable with today's corona discharge systems. U.S. Pat. No. 4,167,466 to Orr, Jr. et al. (1979) describes an electron beam generator with much higher production efficiency. This device requires as little as 0.26 kW-hours of energy to produce a pound of ozone. The patent indicates that high efficiencies are attained by moving oxygen past the beam at high velocities. However the ozone concentrations produced are still less than 1 percent for a single pass through. The patent does indicate much higher ozone production concentrations are possible by repeatedly recycling the oxygen past the beam. However there is no mention of how this can be accomplished cost effectively. U.S. Pat. No. 5,756,054 to Wong et al. (1998) describes an electron beam device that can be used to generate ozone directly from liquid oxygen. This is supported by earlier research that indicated generating ozone concentration levels of up to 10% were generated by an electron beam in liquid oxygen. However the energy dosage had to be applied slowly and the oxygen had to be cryogenically cooled to be maintained in a liquid state. U.S. Pat. No. 5,756,054 discusses an approach that uses cryogenic cooling to separate the ozone from the oxygen. In this way the oxygen not converted to ozone could continue to be processed to maximize ozone production. However it does not address the economics of this process in order to evaluate its cost relative to its benefit.
In summary, a number of corona discharge devices have been used for the production of ozone, but nevertheless they all suffer from a number of disadvantages:
(a) They are large and require considerable space within a facility
(b) They require the use of expensive pulsed or high frequency power supplies
(c) They require periodic cleaning and other maintenance to function effectively
(d) They require water chillers to operate at high efficiencies.
In addition, electron beam generators have been proposed as alternative ozone generating devices, however they also have a number of disadvantages:
(a) Proposed electron beam generators are expensive to manufacture because of their complex configuration and beam focusing requirements.
(b) Their unidirectional or bi-directional beam structure does not allow the system to have the compactness desired for processing systems.
(c) Currently proposed electron beam generators have thus far only generated low concentrations of ozone which may, to some extent be due to recycling limitations.
(d) Additional apparatus proposed for increasing ozone concentrations involving multiple recycling of the oxygen or refrigeration to precipitate ozone are relatively expensive and complicated processes.
A number of patents have been issued for the decomposition of sulfur dioxide and other pollutants using electron beam irradiation. The most important difficulties to overcome for effective irradiation have been penetration of the medium to be processed and spreading the electron beam to effectively process large waste streams. Many innovative techniques have been employed in attempts to overcome these difficulties. For example in U.S. Pat. No. 3,891,855 to Offermann (1975) and U.S. Pat. No. 4,173,719 to Tauber et al. (1979) the process fluid stream is narrowed to allow penetration with a lower energy beam. However converting the fluid stream to a wide, narrow channel can be expensive and cause substantial flow losses and process complications. Other attempts have been made including processing contaminated fluids in the vapor phase as described U.S. Pat. No. 5,319,211 to Matthews et al. (1994). Although penetration of the fluid in the gaseous state is easier, it still requires a complicated flow channel. Furthermore, all electron beam process techniques thus far have been based on treating contaminated fluids where the contaminant is mixed throughout. No effort is made to differentiate and separate the components for preferential processing of only the contaminants.
In summary, electron beam generators have been proposed, and to some extent, used for the removal of sulfur dioxide and other pollutants in the past, however they all suffer from the following disadvantages:
(a) Because of their limited penetration, particularly in denser fluids, the electron beam energy levels must be relatively high which has a direct relationship to their capital cost.
(b) Existing electron beam processors must penetrate and irradiate the entire fluid volume even though the contaminant may be only a small fraction of this volume.
(c) In order to uniformly irradiate fluids with a unidirectional beam, the fluid flow profile must be very flat and wide, which may be expensive to construct for large effluent streams.
(d) The high energy and unidirectional nature of existing electron beam systems necessitates substantial radiation shielding requirements for safety.
SUMMARY OF THE INVENTION
The invention includes apparatus and methods for the production of ozone (O 3 ) and decomposition of contaminants, specifically to a method of using density differences in fluids combined with a cylindrically configured irradiation apparatus for improved production of ozone from air or oxygen and for decontamination. Ozone is used as a treatment for drinking water, wastewater, and related applications where it interacts with organic impurities to implement disinfection. Decontamination applications include removal of gaseous pollutants such as sulfur dioxide from effluent gas and volatile organic compound decomposition in water, wastewater, air and other gases.
A method of and apparatus for generating ozone from oxygen or air with irradiation such as from an electron beam. A means for cooling and preferentially positioning oxygen or air to increase ozone yield efficiency and concentration is employed. The disclosed method and apparatus may also be used for other process applications including waste gas and wastewater decontamination.
Accordingly, several objects and advantages of the present invention for the application of ozone generation are:
(a) to provide a method of ozone generation that preferentially positions the oxygen so that much higher concentrations of ozone can be produced than is possible with the existing technology.
(b) to provide a method of ozone generation that is capable of producing ozone at higher energy efficiencies than is possible with the existing technology.
(c) to provide an ozone generator that is compact and minimizes the space required within a facility.
(d) to provide an ozone generator that uses a simple direct current power supply instead of the pulsed power or high frequency type of device currently used in existing ozone generators.
(e) to provide an ozone generator of which the reaction chamber has virtually no cleaning or maintenance requirements.
(f) to provide an ozone generator that operates effectively without the need for a water chilling device.
(g) to provide an electron beam type ozone generator that does not require the complicated beam focusing systems typically used for unidirectional beam generating devices.
(h) to provide an electron beam type ozone generator that can use a simple, low cost cylindrical chamber geometry similar to standard radio tubes.
A further advantage is to provide an ozone generator which will be able to produce ozone at consistent production levels without the need to perform special tuning of the power supply and reaction chamber as is typically the case for corona discharge devices. Still further objects and advantages will become apparent from a consideration of the ensuing description and drawings.
Regarding embodiments of the invention adapted for use in removing gaseous pollutants, several objects and advantages of the present invention for the destruction of sulfur dioxide and other pollutants and decontamination of fluids are:
(a) To provide a method that can preferentially position sulfur dioxide and other contaminants close to the irradiation source causing them to be decontaminated with a much lower beam energy.
(b) To provide a method that can preferentially position contaminants close to the irradiation source therefore reducing the volume of fluid that must be exposed which reduces the total power needed for contaminant removal or treatment.
(c) to provide an electron beam irradiator that does not require the complicated beam focusing systems typically used for unidirectional beam generating devices.
(d) to provide an electron beam irradiator that can use a simple, low cost cylindrical chamber geometry similar to standard radio tubes.
A further advantage is that because of its low cost configuration, the current invention can be applied to a wider range of pollution treatment applications where irradiation was previously too expensive.
DRAWING FIGURES
In the drawings, closely related figures have the same number but different alphabetic suffixes.
FIG. 1 shows an isometric drawing of an ozone generator operating system.
FIG. 2 shows an assembly of an ozone generator chamber with a section removed to illustrate the interior components.
FIG. 3 shows a cross-section of an ozone generator chamber with a depiction of the oxygen conversion to ozone.
FIG. 4 shows a cross-section of a fluid treatment device with a depiction of the pollutant decomposition.
FIG. 5 shows a device.
Reference Numerals in Drawings:
10
ozone generator assembly
12
electron gun mounting plate
14
high voltage insulator bushing
16
electron gun cathode connection
18
mounting flange
20
liquid cooling chamber
22
cathode emitter
24
electron beam window
26
ozone reaction chamber
28
spiral vane
30
mounting base
32
cooling liquid inlet port
34
oxygen inlet port
38
electron gun power supply
40
vacuum pumping system
DETAILED DESCRIPTION
Description—FIGS. 1 to 4
A typical embodiment of an ozone generator of the present invention is illustrated in FIG. 2 (isometric view). The ozone generator assembly 10 has an electron gun mounted in one end of the assembly that is comprised of the electron gun mounting plate 12 , high voltage insulator bushing 14 , electron gun cathode connection, and a cathode emitter 22 . The electron gun cathode emitter 22 is enclosed in a vacuum by the electron beam window 24 , and at the ends by the ozone reaction chamber 26 . Typically the electron beam window is constructed of thin titanium foil or metallized plastic film. The electron beam window 24 is held in position by soldering or otherwise bonding the window to the spiral vane 28 . It lies in an annular space between the electron beam window 24 and the outer wall of the ozone reaction chamber 26 . The liquid cooling chamber 20 encloses the ozone reaction chamber 26 and creates an annular cooling passage to cool the ozone reaction chamber 26 . The mounting flange 18 and mounting base 30 provide end closures for the vacuum space inside the electron beam window 24 and the liquid cooling chamber 20 .
The entire ozone generator assembly 10 is constructed in a cylindrical geometry to minimize its volume and simplify the construction of the device as well as for functional reasons explained below. The cylindrical construction of the cathode emitter and vacuum enclosure is based on well established standard vacuum tube design. The principal difference is that instead of absorbing the current into the anode such as is done with a standard vacuum tube, the current is transmitted through the cylindrical electron beam window 24 into the oxygen gas or other processed fluids outside the window. In one embodiment the cathode emitter 22 is constructed of a cylindrical array of thoriated titanium oxide filaments. Another embodiment consists of an oxide coated cylindrical cathode or cylindrical dispenser cathode. All of these possible embodiments are economic alternatives for radially emitting the electron beam. Typically the cathode emitter diameter is proportional to type of cathode used and the current that must be emitted. In this embodiment the diameter can range from less than 25 millimeters to several hundred millimeters.
The cathode emitter 22 and electron beam window 24 create anode to cathode accelerating space. A negative high voltage in the range of less than 100,000 volts to several hundred thousand volts with respect to ground at the anode is applied to the cathode emitter 22 . The gap spacing for electron guns in the voltage range indicated may be less than 25 millimeters to well over 100 millimeters. However because of the superior voltage hold-off characteristics of the coaxial geometry, the gap spacing requirement and consequently the vacuum tube diameter is minimized. The vacuum tube anode diameter is limited mainly by the ability to dissipate the heat deposited in the electron beam window 24 . As will be described later, the window is well cooled by rapid flowing process fluid. And this allows much higher energy output per unit area than is possible with corona discharge devices.
An embodiment of this device includes a bias grid surrounding the emitter to regulate the emitted current. The grid bias voltage is generally provided by an additional power supply through the same high voltage insulator bushing 14 that provides the high voltage power for the cathode emitter 22 . High voltage cables normally transmit the high voltage power for the cathode emitter 22 . In one embodiment of the invention, the high voltage cable is eliminated by connecting the electron gun cathode connection 16 directly to the electron gun power supply 38 (FIG. 1 ).
One embodiment of this invention is the unique combined construction of the high vacuum enclosed space and electron beam window 24 . Typical electron gun systems incorporate a high vacuum chamber constructed of stainless steel with a beam window mounted in one side of the chamber. This typical construction is complicated and expensive. One of the embodiments of this invention is that the electron beam window 24 is cylindrical in shape and forms the entire vacuum space by attaching it to the spiral vane 28 . This spiral vane 28 serves several purposes and one of them is to form the cylindrical support for the electron beam window. For fluids that create relatively high pressures on the electron beam window 24 , a ring support is placed inside the enclosed vacuum space to internally support the window. To maximize the electron beam transmission into the oxygen or fluid the ring support is formed in the electron beam shadow of the spiral vane 28 .
The spiral vane 28 is constructed in a spiral pattern and creates the oxygen or fluid path that is to be processed. The width of the spiral vane is dependent on the heat transfer required to absorb the beam energy and is typically 2 to 20 millimeters wide. The depth of the spiral vane 28 is established by the energy of the beam and the density of the fluid being processed. For liquids this depth may be as small as 0.25 millimeter and for gases the depth may be in excess of 25 millimeters. An important embodiment of this invention is that the depth of the vanes in the reaction chamber is established to insure that most of the beam will be absorbed by the fluid. Very little of the beam should strike the reaction chamber wall in order to maximize ozone production as defined in the operation. Typically the reaction chamber 26 and the spiral vane 28 are constructed of high thermal conductivity metal such as copper or aluminum for more efficient heat transfer. A high conductivity coating such as silver is typically used to protect the surface from corrosion or oxidation without compromising the chamber conductivity.
From the description above, a number of advantages of this ozone generator and fluid processor become evident:
(a) Unlike currently designed ozone generators based on corona discharge, the cylindrical construction of this invention is simple and economical to manufacture.
(b) Electron beam generators have a much higher energy output per unit of surface area, which allows this device to be much more compact than conventional ozone generators.
(c) The power supply for this device can be a standard high voltage direct current unit instead of a pulsed power device. And if pulsed power is desired a relatively simple grid supply can be used to turn the electron beam on and off.
(d) Unlike corona discharge ozone generators, the vacuum tube type of construction has a long history of reliable performance requiring very little maintenance.
(e) Because of the substantially smaller size of this device compared to a corona discharge type system, it is much easier to provide maintenance without the need for special equipment.
(f) By incorporating the centrifuge effect into the process, my generator can selectively direct its energy at oxygen instead of at previously generated ozone leading to the potential to produce much higher concentrations of ozone.
(g) This same centrifuge effect allows selective irradiation which provides the capability to use lower energy, lower capacity electron beams for decontamination than conventional irradiators.
Operation—FIGS 1 , 2 , 3 , 4
In the preferred embodiment of the ozone generator and fluid processor 10 oxygen gas is delivered to the oxygen inlet port 34 . The oxygen is typically transferred from an oxygen source such as a cryogenic vessel filled with liquid oxygen. The pressure required to transfer the liquid oxygen is typically generated by the pressure setting on the cryogenic vessel. Once the oxygen enters the oxygen inlet port 34 it then enters the cavity formed by the spiral vane 28 inside the reaction chamber 26 where the oxygen follows in a spiral pattern. An electron beam is emitted from the cathode emitter 22 and is accelerated radially outward from its center by a negative high voltage. The cathode voltage is in the order of 100,000 volts with respect to the outer wall or window where the electron beam exits. This radially directed electron beam has sufficient energy so that the majority of the beam penetrates the cylindrical electron beam window 24 and is deposited into the oxygen gas that is spiraling around the exterior of this window. The electron beam continues to traverse through the oxygen or other fluid and dissipates its energy therein. The electron beam that is deposited into the oxygen has sufficient energy to convert some proportion of it to ozone. Once the ozone and remaining oxygen reach the end of the spiral vane, the two fluids exit the reaction chamber and are transferred to the process requiring the ozone.
In order to produce ozone, tremendous amounts of heat must be deposited into the oxygen. Without the benefit of cooling, the overall temperature of the gas could exceed 1000 degrees Celsius. This excessive temperature would then cause decomposition of the ozone produced leading to limited ozone production. Efficient cooling of the gas is required to prevent this decomposition. The spiral rib pattern of the reaction chamber combined with high velocity flow of the fluid provides the cooling necessary to significantly reduce decomposition of the ozone generated. This flow is typically in the 1000 to 3000 meters per minute for efficient cooling. The heat absorbed by the spiral ribs is transferred into the cooling water or fluid flowing on the exterior of the reaction chamber rib structure.
This high-velocity cooling requirement also creates the added benefit of higher ozone energy conversion efficiency as mentioned in the earlier patent.
The most important characteristic of this method of ozone generation is that the spiral gas flow creates a centrifuge effect. This centrifuge effect causes the oxygen and ozone gases to separate with the newly formed higher density ozone gas moving to the outer edge of the spiral cavity. This separation caused by centrifugal force allows the oxygen to continue to be positioned closest to the incoming electron beam. FIG. 3 shows how the ozone and oxygen move through the generator. The resultant benefit is that the oxygen gas absorbs most of the beam and relatively small amounts penetrate the layer of oxygen gas to strike the outer layer of ozone just produced. This combined effect of high velocity flow and centrifugal force created with the spiral motion creates the potential for unprecedented concentrations of ozone while still maintaining high-energy efficiency ozone production.
In summary, the key to high efficiency ozone production by electron beam is high velocity oxygen flow past the beam. And the key to producing high concentrations of ozone is recycling the oxygen while separating the generated ozone to prevent its decomposition. The method of spiral gas flow of this invention allows these key events to occur simultaneously and also is the key to the removal of high levels of generated heat. And the unique cylindrical radial electron beam pattern with its inherent compact beam geometry facilitates the employment of this unique ozone production process.
This same method can be employed for processing other fluids as well. The key is that the fluids that require processing must have a significant density difference than the other fluids in the stream. There are some differences in operation, but the principles are the same. For example, sulfur dioxide, (SO 2 ) has a significantly higher density than the other gases in a smokestack effluent stream. In this instance, since the gas to be irradiated is denser than the other gases, the electron beam geometry has to be radiated towards the center of the axis instead of outward. Another major difference is that the heat dissipation requirements are much lower than for ozone production. Therefore there may not be a requirement for facility cooling.
FIG. 4 shows an embodiment of this invention to decompose a pollutant. In this example it is assumed that the pollutant to be decomposed is denser than the other gases in the flow stream, and that no additional cooling is required. In this embodiment the cathode is shown radiating inward. The pollutant as well as the other gases are fed into the spiral vane chamber 26 which in this case shows the chamber wall inboard. The electron beam window 24 attaches on the outer edge of the spiral vane 28 . As the gas or fluid flows in the spiral pattern, centripetal force causes the denser pollutant to flow to the outer wall, which is in this case, is the electron beam window 24 . The inward radiating electron beam therefore is mainly absorbed in the pollutant causing it to decompose or otherwise be altered to an acceptable state. This process substantially reduces the power required because a much smaller percentage of fluid is processed, and the beam penetration requirements are much lower.
The inward radiating electron beam generator configuration shown in FIG. 4 can have other variations. For example for stack gases where it is desirable to minimize flow interruptions and discontinuities, a spiral vane can be mounted axially in the beam path so that the gas flows directly out of its pipe, through the spiral vane, and back into pipe of the same diameter. FIG. 5 shows an example of this kind of device.
In summary, the method of spiraling the fluid to create the centrifuge action, coupled with the unique circular geometry of the irradiator that allows radiation inward as well as outward provides a unique alternative for cost effective processing with electron beam. By concentrating and isolating the fluid to be treated, a substantial reduction in both power requirements and capital equipment requirements is attained.
Accordingly, the reader will see that the ozone generator of this invention can be used to produce ozone efficiently and economically. And because of the processes incorporated and its unique geometry it has the potential to attain much higher ozone concentrations more efficiently than existing ozone generating devices. These advantages mean that both less power and less oxygen are required than corona discharge devices to generate the same quantities of ozone. As a processor for contaminated fluids the invention has the further advantages that it only requires a fraction of the voltage that conventional electron beam processors require. And since it does not need to process the entire fluid stream, it requires only a fraction of the throughput normally required for such a device. Furthermore the ozone generator and fluid processor apparatus has the following additional advantages:
Because of its simple construction, it can be manufactured at a considerably lower cost than corona discharge ozone generating devices.
It is much smaller than existing corona discharge generating devices and can therefore be more easily installed in limited spaces.
It is powered by much simpler dc power supplies that are less expensive to build than medium to high frequency or pulsed power supplies that are now used for existing ozone generators.
It requires little or no cleaning and maintenance because there are no corona discharge components that wear and must be periodically cleaned and replaced.
Unlike existing ozone generators, there is no requirement for expensive chilled water equipment that will take up valuable plant operating space to support efficient production of ozone.
It allows the use of standard vacuum tube cylindrical geometry, a much lower cost construction than unidirectional electron beam generating devices.
Although the description above has been directed at describing particular embodiments of the method and device in accordance with the patent requirements, it should not be construed as limiting the scope of the invention but as merely providing illustrations of some of the presently preferred embodiments of this invention. For example, a pulsed power high voltage supply can be used instead of a dc supply. The cathode emitter can be square or rectangular instead of cylindrical. The high voltage insulator bushing can be tapered in a different direction than what is shown. The spiral vane can be a group of vanes in either a spiral pattern or in a cylindrical pattern that move the fluid in parallel with one another around the electron beam window. The oxygen can be directed into any flow pattern that achieves the preferred orientation of the oxygen closest to the beam and the ozone farthest from the beam. For fluid process streams where the pollutants to be treated are denser than the fluid, the irradiation is directed inwards as shown in FIG. 4 .
It should also be noted that this electron beam device can be used for a number of other applications where the benefit of electron beam processing combined with the centrifuge effect facilitate the preferential processing of dissimilar density materials. As previously mentioned, the dissimilar densities of exhaust or smokestack gases can allow the different density gases to be preferentially processed by the electron beam. For example, for denser gases such as sulfur dioxide, the centrifuge effect of spiraling the gas causes it to move to the outermost section of the reaction chamber. This then requires the irradiation device to be directed inward to decompose the sulfur dioxide gas as shown in FIGS. 4 and 5.
As also mentioned, this process is also applicable to liquids such as water and other fluids which may contain contaminants that are at different densities than the main fluid stream. One specific application is for irradiating suspended solids in a liquid. By using the centrifuge effect caused by spiraling the fluid with its suspended solids, the solids which are denser move outward in the spiraled fluid stream and are therefore irradiated by a process beam such as shown in FIG. 4 .
Another application that this can be used for is radiation curing. For example, polymers that are to be applied are often transferred in a solvent that is of lower density. The process of spiraling the polymer that must be cured past an irradiator prior to its being applied to a substrate may save considerable curing costs. In this case since the polymer is denser than the solvent carrying it, it is forced against the outside wall and is therefore preferentially treated by an inward electron beam device such as depicted in FIG. 4 .
Another application is for fluid sterilization when there is a mixture of fluids that have significantly different densities. If only one of the fluids requires irradiation for pasteurization or sterilization, this component can be preferentially positioned to the outer wall if it is denser whereby the device in FIG. 4 would be applicable. If the fluid to be treated was a lower density than the other fluid or fluids, this lower density material would migrate to the inner wall of the spiral chamber and would therefore be irradiated with an outwardly directed beam as shown in FIG. 3 .
Food pasteurization with an irradiation source is also an application for which this device can be used. For example if a food component that needs to be treated is of a different density than other components within the food mixture, the particular component requiring treatment can be separated using the centrifuge effect so that it can be positioned closest to the irradiation source. If it is denser than the rest of the food ingredients it will migrate towards the outermost perimeter of the spiral path and will thus be irradiated with the inward pattern beam as shown in FIG. 4 . If it is lighter than the rest of the food components it will migrate towards the innermost area of the spiral path so that it can be irradiated with the outwardly oriented beam.
There are many other applications of how this process and device can be used that are not enumerated here. Thus the scope of the invention should be determined by the appended claims and their legal equivalents, rather than by only the examples given. | A method of and apparatus for generating ozone from oxygen or air with irradiation such as from an electron beam. A means for cooling and preferentially positioning oxygen or air to increase ozone yield efficiency and concentration is employed. The disclosed method and apparatus may also be used for other process applications including waste gas and wastewater decontamination. | 1 |
BACKGROUND OF THE INVENTION
1. Technical Field
This invention relates to the field of electric utility power conditioning, and more particularly to power conditioners which involves a) maintaining voltage amplitude on the output to the load constant while an input utility voltage amplitude varies, and b) attenuating any distortions present in the input utility voltage waveform to the output.
The universality of the power conditioner of the present invention is in its ability to condition electric power delivered by different electrical services like 208/120 V dual phase service with two phases having phase shifts of 120 or 240 degrees; 240/120 V split phase service with two phases having phase shifts of 180 degrees; or single phase service with any voltage like 200 V, 208 V, 220 V, and 240 V. The frequency of any service can be any frequency used in the world, namely 50 or 60 Hz nominally, but generally in the range of 45 to 66 Hz.
2. Related References
Related references in the present invention's field include power supplies, power conditioners, and uninterruptible power supplies (UPS). Three patents have been found which are closely related to this subject.
U.S. Pat. No. 5,017,800 to Divan describes an electronic circuit which acts as a single phase power conditioner or UPS for only one type of electrical service - single phase with one grounded conductor (neutral). The main disadvantage of using this circuit is that output voltage shall be always smaller than the input voltage. This is a significant problem because the majority of power related problems are undervoltages and sags. Because the purpose of the power conditioner is to regulate the output at nominal nominal service value, like 120 V or 208 V, the conditioner will not be able to do it alone when input voltage is below nominal, undervoltage. Divan suggests using a transformer to amend this problem, see FIG. 4, but this greatly diminishes the value of the invention because the transformer's weight and size far exceed the weight and size of the electronic portion of the device. The use of the transformer also increases cost to such an extent that the smaller number of power semiconductor switches claimed in this invention versus similar purpose instruments does not provide for a total cost advantage. Regardless of these disadvantages, Divan can not be used for dual phase and other services, and therefore can not be a universal service conditioner/UPS.
U.S. Pat. No. 4,935,861 to Johnson et al. describes an invention almost identical to Divan's with capacitors C1 and C2 used instead of the active switches S1 and S3 used in Divan's invention. This invention has all the same disadvantages as Divan's plus one more. In Divan's invention, the waveform of the input current has limited control by switches S1 and S2 in such a way that the current can be sinusoidal in waveform and therefore input power factor values close to unity can be realized. Conversely, in Johnson's invention, the input circuit acts as a regular rectifier with capacitive filter, C1 and C2. It is well known that the input power factor of such a circuit is low, generally in the range of 0.4 -0.6. The current waveform is very distorted from sinusoidal and therefore there are large current harmonics which cause significant overheating of neutral conductors in the building wiring. This is one of the most frequent causes of building fires.
U.S. Pat. No. 4,934,822 to Higaki describes an AC-AC power supply acting as a power conditioner. This invention is an improvement over U.S. Pat. No. 4,827,151 to Okado. Okado's problem was that high frequency switching noise was generated on both output power conductors, compared to the grounded input conductor of Higaki's FIG. 2. Higaki's invention eliminated this high switching frequency component but left other signals on both output power conductors shown in FIGS. 4C and 4D. Those signals have sharp edges which contain high frequency harmonics that cause different problems in connected loads, like computer malfunction, magnetic component overheating, etc. All loads are designed to operate from sine waveform voltages on any power carrying conductors. Therefore this invention can hardly be used alone as a power conditioner, but only in conjunction with an isolation transformer which can eliminate this problem called "common mode voltage" Because of this disadvantage, Higaki can not be applied for universal service applications.
OBJECTS OF THE PRESENT INVENTION
An object of the present invention is to overcome the disadvantages of the related references described above and to provide a power conditioner usable with any electrical service around the world.
Another object of the present invention is to provide a power conditioner applicable to minicomputers. Generally, minicomputers require power in the range 3 to 15 kVA. In this power range, common electrical services worldwide include:
a) Dual phase 208/120 V consisting of two phases 120 V each with common grounded conductor (neutral). Phase voltages are phase shifted 120 or 240 degrees and therefore voltage between phases is 208 V.
b) Split phase 240/120 V consisting of two phases 120 V each with common grounded conductor (neutral). Phase voltages are phase shifted 180 degrees and appear as a single phase voltage split into two equal parts.
c) Single phase voltages with nominal amplitudes 200 V (Japan); 208 V, 220 V (Continental Europe), 240 V (United Kingdom countries) and many other service voltages in between. In these services, generally one power carrying conductor is grounded but not identified as such. It is also possible to have the center point (neutral) of the electrical service transformer grounded as in 208 V service in the USA or Canada.
The frequency of the sinewave voltage of the above services nominally is 50 or 60 Hz. In cases small utility generators, frequency can be in the range 45 to 66 Hz.
The advantage of a universal power conditioner is that only one physical unit per minicomputer system is required for service anywhere in the world. The present invention fulfills this advantage.
SUMMARY OF THE INVENTION
The present invention contains:
a) A two phase or single phase input voltage boost converter which draws sinewave current from any phase of the connected service. The converter is symmetrical in construction in regards to a common conductor which is connected to the input common conductor-neutral when it is available.
b) A DC link with two capacitors symmetrically connected to the same common conductor.
c) A two phase buck inverter producing a regulated sinewave voltage waveform on two output power conductors, symmetrically, versus the common conductor, in synchronism and phase locked to the input voltage frequencies and phases.
d) Input and output filters to filter out high frequency switching and its harmonics, also symmetrical in construction versus the common conductor.
This combination of the functional blocks and total symmetry of the circuit allows the present invention to uniquely achieve the desired functioning: worldwide service application, sinewave input current, and a regulated nominal sinewave output voltage free of distortions typical in the input utility service voltage.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows power circuits of the symmetrical universal AC-AC power conditioner of the present invention.
FIG. 2 shows control circuits for the boost converter of the symmetrical universal AC-AC power conditioner shown in FIG. 1 of the present invention.
FIG. 3 shows control circuits for buck inverter of the symmetrical universal AC-AC power conditioner shown in FIG. 1 of the present invention.
FIGS. 4A, 4B, and 4C show examples of voltage diagrams for the case of dual phase conditioning with 120 degrees phase shift between phases X and Y.
FIG. 5A shows an equivalent circuit of operation of the present invention, and FIGS. 5B and 5C show voltage phase diagrams for dual phase service with a phase shift of 120 or 240 degrees.
FIG. 6A shows an equivalent circuit of operation of the present invention, and FIG. 6B shows a voltage phase diagram for dual phase service without use of the common grounded conductor, usually 208 V service in the USA or Canada.
FIG. 7A shows an equivalent circuit of operation of the present invention, and FIG. 7B shows a voltage phase diagram for single phase service with center point grounded, usually called split phase service.
FIG. 8A shows equivalent circuit of operation of the present invention, and FIG. 8B shows a voltage phase diagram for single phase service with one of the input conductors grounded.
DETAILED DESCRIPTION
Power Circuits, FIG. 1
The first major functional block of the conditioner of the present invention is Boost Converter 1. It is a full bridge circuit identical to one used in full bridge inverters. It consists of four semiconductor switches 11, 12, 13, 14. Those switches have control terminals marked "C" Many different controlled semiconductors may be used as switches like bipolar transistors, Darlington transistors, MOSFETS, IGBTs, GTOs, etc. The arrow shows the direction of the controlled current flow. Switches 11-14 control current flow in one direction shown by this arrow. The power supplied to the control terminal is negligible in comparison with the power turned on or off by the switch. The switches are connected between incoming phase conductors 53 and 54, and output DC conductors 51 and 52. Conductor 51 ("+DC conductor 51") has positive voltage in relation to conductor 52 ("-DC conductor 52"). Switches 11-14 are connected so that controllable current flows from +DC conductor 51 into phase conductor 53 or 54 and from phase conductor 53 or 54 into -DC conductor 52. There are also four diodes 15, 16, 17 and 18 connected in parallel with switches 11-14 so that the current flows in the opposite direction versus the one allowed by switches 11-14.
The second major functional block is Buck Inverter 2 which is identical in construction to converter 1. It connects output phase conductors 57 and 58 to +DC conductor 55 and -DC conductor 56. The components are four semiconductor switches 21-24 and four diodes 25-28. The connection of components is identical to Converter 1.
The third functional block is input filter 3. It has two chokes 31 and 32 connected in series with phase power conductors, and two capacitors 33 and 34 connected between each input phase conductor 59 and 61, and symmetry conductor 60. Choke 31 connects input phase conductor 59 with phase conductor 53 feeding converter 1. Choke 32 connects the other input phase conductor 61 to the phase conductor 54 feeding converter 1. The electrical parameters of chokes 31-32 and capacitors 33-34 are substantially the same. The input phase X terminal 101 is attached to input phase conductor 59, input phase terminal 102 is attached to input phase conductor 61, and input neutral terminal 103 is attached to symmetry conductor 60.
The forth functional block is output filter 4. It has identical construction as the input filter 3. Choke 41 connects output phase conductor 62 with phase conductor 57 fed by inverter 2. Choke 42 connects output phase conductor 63 with output phase conductor 58 fed by inverter 2. Capacitors 43 and 44 are connected between symmetry conductor 60 and output phase conductors 62 and 63 respectively. Again, electrical parameters of chokes 41-42 and capacitors 43-44 are substantially identical; they can have the same parameters as input filter 3 but are not required to be the same. Output phase X conductor 62 is attached to output phase X terminal 104, output phase Y conductor 63 is attached to output phase Y terminal 105, and output neutral terminal 106 is attached to symmetry conductor 106.
There are two DC link capacitors 96 and 97. Capacitor 96 is connected between +DC link conductor 94 and symmetry conductor 60, and capacitor 97 is connected between -DC link conductor 95 and symmetry conductor 60. Capacitors 96 and 97 have substantially identical electrical parameters.
For reliability and cost, current snubbers 6, 7, 8, 9 should be used. In principle, conductors 51, 94, 55 and 52, 95, 56 can be connected to together in each group without affecting performance of the present invention. Snubbers 6-9 reduce electrical stress imposed on all power semiconductors and diodes during turn on and off of switches during operation. Importantly, snubbers 7 and 8 will have components with substantially identical electrical parameters, and snubbers 6 and 9 also will have components with substantially identical electrical parameters. Snubber choke 91 connects conductors 51 and 94, snubber choke 71 connects conductors 55 and 94, snubber choke 61 connects conductors 52 and 95, and snubber choke 81 connects conductors 56 and 95. Each snubber choke has a parallel circuit consisting of a resistor and a diode: choke 91--resistor 92 and diode 93; choke 71--resistor 73 and diode 72; choke 61--resistor 62 and diode 63; and choke 81 resistor 83 and diode 82. The diodes are connected so that current is conducted from inverter 2 to converter 1 by diodes 72 and 93 connected to chokes 7 and 9 respectively, and from converter 1 to inverter 2 by diodes 63 and 82 connected to chokes 6 and 8 respectively.
Control Circuits for Boost Converter 1, FIG. 2
FIG. 2. shows three voltage level conditioners 201, 202 and 203 coupled to converter 1 of FIG. 1. The function of conditioners 201-203 is to reduce power circuit voltage values down and to shift the voltage level if necessary so that common integrated circuits can be used to operate on those voltages. Conditioner 201 conditions the voltage of both DC link capacitors 96 and 97. Input to conditioner 201 is connected to +DC conductor 94 and -DC conductor 95. Conditioner 202 conditions input voltage of phase X and is connected on the input to terminals 101 and 102. Conditioner 203 conditions input phase voltage Y and is connected on the input to terminals 102 and 103.
Output of conditioner 201 is input to error amplifier 204 which has the other input connected to reference voltage V ref .
Output of amplifier 204 and output of conditioner 201 are connected to a summing amplifier 220. The output of amplifier 220 feeds one of two inputs of voltage multipliers 207 and 208. The other inputs of multipliers 207-208 are connected to the output of voltage conditioners 202 and 203.
Output of multiplier 207 is connected to the input of pulse width modulation (PWM) circuit 209, and output of multiplier 210 is connected to the input of substantially identical PWM circuit 210. There are PWM circuits with voltage or current control for switching regulators and both can be employed. If current control PWM are used, current sensors should be added to power circuit of converter Output of PWM circuit 209 is fed to driver 214 and though logic inverter 211 to driver 213. Likewise, output of PWM circuit 210 is fed to driver 216 and through logic inverter 212 to driver 215.
All driver circuits 213-216 are substantially identical, and they function to shift the level of the logic voltage to make it compatible with the level required by control terminals of converter semiconductor switches 11-14, i.e., to change the amplitude of the voltage for required operation of the control terminal of those switches and to provide sufficient power to those terminals. There are numerous driver circuits well known which are based on transformers, optocouplers, and level shifters. However, it is immaterial for the purpose of this invention which driver is used.
Driver 213 output feeds control terminal of switch 11, driver 214 output feeds control terminal of switch 12, driver 215 output feeds control terminal of switch 13, Driver 216 output feeds control terminal of switch 14.
Control Circuit for Buck Inverter 2, FIG. 3
FIG. 2 shows two substantially identical sinewave reference waveform generators 301 and 302. Both of them have phase lock loop circuits to synchronize the frequency of this waveform to the input service frequency and to be in phase lock with input phases X and Y, respectively. There are numerous well known circuits which function in this way. Phase lock and synchronization signal input to circuit 301 is provided from input phase X via conditioner 202 from its output 205, and phase lock and synchronization signal to circuit 302 is provided from input phase Y via conditioner 203 from its output 206, both shown in FIG. 2.
Two substantially identical voltage level conditioners 303 and 304, substantially identical in functioning to conditioners 202 and 203, are shown in FIG. 3 Conditioner 303 inputs are connected to output phase X terminals 104 and 106, and conditioner 304 inputs are connected to output phase Y terminals 105 and 106.
Output of reference generator 301 and phase X conditioner 303 are connected to the input of the error amplifier 305, and output of reference generator 302 and phase Y conditioner 304 are connected to the input of the error amplifier 306. Outputs of reference generator 301 and error amplifier 305 are connected to summing circuit 307, and outputs of reference generator 302 and error amplifier 306 are connected to summing circuit 308. Outputs of summing circuits 307 and 308 feed PWM circuits 309 and 310 respectively.
Output of PWM circuit 309 is connected to driver 313 and via logic inverter 311 to driver 314. Similarly, output of PWM circuit 310 is connected to driver 315 and via logic inverter 312 to driver 316. Driver circuits 313-316 are substantially identical in functioning to driver circuits 213-216 with exception of different electrical performance required if inverter 2 switches 21-24 are different from converter 1 switches 11-14.
DESCRIPTION OF OPERATION
General Description of Operation, FIG. 1
Converter 1 with its filter 3, snubbers 6 and 9, and its control circuit charges capacitors 96 and 97 with equal charge which creates a voltage value higher than the peak voltage value in any utility phase X or Y on the input. Converter 1 boosts utility voltage and therefore is called a Boost Converter. The capacitance value of capacitors 96 and 97 is such that the voltage on these capacitors is near constant during each cycle of the utility voltage. For example, for a utility voltage input of 120 VRMS (170 V peak), capacitor 96 and 97 would preferably have a value of 220 V each.
The converter control circuit of the present invention regulates voltage on capacitors 96 and 97 to the predefined value. So, when the amplitude of the utility phase voltage changes to be below nominal value or above nominal value, voltage on capacitors 96-97 is maintained or regulated at the constant level.
FIG. 4A shows two utility phase voltage waveforms 401, phase X, and 402, phase Y, for the case of dual phase service with 120 degrees phase displacement between phases. The range of usual waveform change is also shown for each phase. FIG. 4B shows the DC voltage 403 on capacitors 96 and 97 versus voltages in incoming utility phases shown in FIG. 4A.
Inverter 2 with its filter 4, snubbers 7 and 8, and its control circuit functions opposite to converter 1. It inverts the DC voltage on capacitors 96 and 97 to alternating AC voltage waveforms on its output to a load, also on phases X and Y. FIG. 4C shows inverter output voltage waveforms for both phases for the same case of dual phase utility service, waveform 404 for phase Y and waveform 405 for phase X. The amplitude and waveform of 404-405 is regulated by inverter 2 to be close to nominal value for the utility service. Because the voltage on capacitors 96 and 97 is larger than the largest overvoltage in the incoming utility phases, inverter 2 reduces it to nominal value on the output. It acts as a buck regulator and is therefore called a Buck Inverter.
It is evident from FIG. 4 that the whole device acts as a power conditioner. The output voltage waveforms are constant while input voltages change. There are numerous high frequency, versus utility service frequency, distortions of the utility voltage waveform. Those distortions are attenuated by filter 3 in conjunction with capacitors 96 and 97. Because those capacitors have enough capacitance to maintain voltage near constant while the input voltage varies with utility service frequency, capacitors 96-97 are able to do even more so under distortions at higher frequencies and shorter duration. Output inverter 2 voltage waveforms are internally controlled and regulated and because the input voltage to inverter 2 from capacitors 96 and 97 is stable within and outside of the frequency bandwidth of this regulator, the output voltages are stable and distortion free.
Symmetrical Operation
There are three sets of capacitors: input filter 3--capacitors 33 and 34; output filter 4-- capacitors 43 and 44; and DC link capacitors 96 and 97. Capacitors in each set have substantially the same electrical characteristics and divide input voltage, output voltage, and DC voltage in half versus the conductor which connects their common terminals. Voltage on those capacitors is symmetrical versus this common conductor, and allows for universal service application as will be described below.
Converter 1 Power Circuit Operation
Referring again to FIG. 1, under steady state conditions, capacitors 96 and 97 are charged to voltages exceeding peak phase voltages. There is positive voltage on conductor 94, versus symmetry conductor 60, and there is negative voltage on conductor 95, versus symmetry conductor 60. Switches 11 and 12 are turned on and off, pulse width modulated, with a switching frequency much higher than the utility service frequency. Switches 11 and 12 are complementary on or off during each period of the switching frequency, i.e., if switch 11 is on, then switch 12 is off, and vice versa.
During a positive cycle of utility voltage in phase X, when switch 12 is on, the sum of voltages in utility phase and on capacitor 97 is applied across choke 31. Then, the current through this choke starts increasing until switch 12 is turned off. At this instant, choke 31 current is switched from going through switch 12 to going through diode 15 to charge capacitor 96. The circuit acts as a boost converter. During a negative cycle of the utility voltage in phase X, current in choke 31 is increasing in value when switch 11 is on and capacitor 97 is charged through diode 16. Phase Y of converter 1 uses switches 13 and 14 and diodes 17 and 18, and operates similarly. Both utility phases are used to charge capacitors 96 and 97. The purpose of filter capacitors 33 and 34 is to filter switching frequency current fluctuations drawn by converter 1 from utility service phase conductors through chokes 31 and 32.
The purpose of snubber inductors 91 and 61 is to limit the rate of rise of the current through, for example, diode 15 and switch 12 when switch 12 is turned on. At this instant, because of diode recovery characteristics, the diode and switch are in a conducting state and short capacitors 96 and 97 in absence of chokes 61 and 91. The same current rise limiting effect occurs when the three other switches 11, 13, and 14 are turned on. The diode-resistor circuits across snubber chokes 91 and 92 discharge those chokes after the recovery period of diodes 15-18 which is usually within the 100 nano-second range.
Inverter 2 Power Circuit Operation
Inverter 2 phase X operates in the following way. Switches 21 and 22 are complementary turned on and off during each period of the switching frequency. This switching frequency is much higher that utility service frequency and not necessarily the same as the converter 1 switching frequency. When switch 21 is on, voltage across capacitor 96 is equal to 1/2 of the DC link voltage between conductors 94 and 95, and is applied on the input of the filter 4, choke 41 and capacitor 43. It causes current to increase through choke 41. When switch 21 is turned off, current through choke 41 gets diverted through diode 26 and voltage across capacitor 97 is applied across the same filter, choke 41 and capacitor 43. If switch 21 is in its on state 50% of the switching period, those voltages are equal in amplitude and duration, and opposite in polarity. Therefore the voltage on the filter output is zero as the filter averages the input voltage. When switch 21 is on longer than 50% of its period of switching frequency, positive polarity voltage is produced on the output capacitor 43, and when the period is less than 50%-negative polarity is produced. The maximum amplitude on the output is equal to the voltage value on capacitors 96 and 97. The circuit acts as a buck converter. The same phenomena happens when the current is flowing out of choke 41. Then switch 22 and diode 25 act as a buck converter. In combination, both pairs, switch 21 and diode 26, and switch 22 and diode 25, act as a buck converter for any direction of the current though choke 41. The other phase (Y) of inverter 2, consisting of switches 23 and 24 and diodes 27 and 28, operates substantially identically.
Filter capacitors 43 and 44 filter out switching frequency current fluctuations from propagating to the load output. Snubbers 7 and 8 operate identically to snubbers 6 and 9. They limit the rate of current rise from capacitors 96 and 97 at the instant when any switch 21-24 is turned on and its corresponding diode is in the recovery period of less than approximately 100 nanoseconds.
Converter 1 Control Circuit Operation
Referring to FIG. 2, voltage on DC link between conductors 94 and 95 is fed through voltage level conditioner 201 to one input of the error amplifier 204, with reference voltage Vref on the other input. When both of those voltages are the same, the output of amplifier 204 is zero; when they are different, the difference is amplified with high gain determined by the DC voltage regulation requirements. Both the output of the error amplifier 204 and conditioned voltage from 201 are fed into summing amplifier 220 which creates an amplitude reference for pulse width modulation circuits 209 and 210. The output of summer 220 is fed on one input of voltage multipliers 207 and 208 which are fed on the other inputs with voltage waveforms proportional to waveforms on utility phases X and Y, through respective conditioners 202 and 203. Outputs of multipliers 207 and 208 are proportional to utility phase voltage waveforms X and Y, and have the same frequency and phase. Amplitudes of those waveforms are proportional to the output of summer 220. When the load on DC capacitors 96 and 97 changes, it causes the voltage on these capacitors to be near constant, or regulated.
Regulated voltage waveforms from multipliers 207 and 208 are fed to PWM circuits 209 and 210. Circuits 209 and 210 function to produce a chain of pulses on the output which have pulse widths proportional to the value of the input voltage at the instant of the pulse generation. The frequency of those pulses is much higher than the utility service frequency. There are numerous well known PWM methods and circuits which can be used.
Output of PWM circuits are fed to drive semiconductor switches in converter through its respective drivers 213-216. As was shown earlier, each set of switches, 11 and 12, and 13 and 14, are turned on or off complementary. This is accomplished by logic inverters 211 and 212. When one of the switches in the set is on, the other is off.
Drivers 213-216 shift the level of voltage to match with the voltage level on control terminal "C" of any switch 11-14, change the voltage amplitude to match with the one required on terminals "C", and provide sufficient power. There are numerous well known driver circuits.
PWM signals driving switches 11-14 cause average voltage on conductors 53 and 54 to be almost equal to phase voltages X and Y respectively. This creates a condition for unrestricted current flow in and out of the DC link between converter 1 and inverter 2 to and from utility phases X and Y. If the current control method is selected for PWM circuits, the waveform of the current in each phase can be made to order and, in particular, is preferably a sinewave, in phase with utility voltages. This is the desired condition for a unity power factor.
Inverter 2 Control Circuit Operation
Referring to FIG. 3, two sinewave voltage reference generators 301 and 302 are shown. Both have phase lock loop circuits which synchronize and phase lock those waveforms to utility phase voltages X and Y respectively. The outputs of those generators are fed to error amplifiers 305 and 306 which have on the other input, feedback voltages from output phases X and Y of inverter 2. When voltage waveforms on the input of the error amplifiers are the same, an error voltage on the amplifiers, output is zero. Output of error amplifiers and reference generators are fed to summing amplifiers 307 and 308.
PWM circuits 309 and 310 for each phase X and Y are fed by summing amplifiers output voltage waveforms. They function similarly to converter control circuits 209 and 210 and produce a chain of pulses with widths proportional to voltage values on the input. Those chains of pulses are fed to inverter switches 21-24 through drivers 313-316 and logic inverters 311 and 312, which all function similar to converter control drivers 213-216 and logic inverters 211-212. The result is that the average voltage on conductors 57 and 58 of inverter 2 is proportional to sinewave reference waveforms generated by internal generators 301 and 302. Because filter 4 averages the voltage on conductors 57 and 58, the output voltages on phases X and Y have a sine waveform at the same frequency and phase as utility phases X and Y and with the amplitude arbitrarily regulated by selecting parameters for the control circuit. Usual selection requires the amplitude of output voltage on both phases to be the same and equal to the nominal value of the utility service voltage.
In summary, the transfer function for the power conditioner of the present invention is:
V.sub.load X =V.sub.nom *sin (w.sub.util *t);
V.sub.loadY =V.sub.nom * sin(w.sub.util * T+phase X-Y); and
V.sub.util X =V.sub.X *sin (w.sub.util *t); and
V.sub.utily =V.sub.y *sin (w.sub.util *t+phase X-Y).
where:
V util =2f util ;
f util =utility service frequency;
t=time; where:
V X =peak value of voltage in phase X;
V Y =peak value of voltage in phase Y; and
V nom =nominal peak phase volage
So, the output voltages on phases X and Y, in relation to symmetry conductor 60, are the same in frequency and phase as utility voltages on phases X and Y, respectively, in relation to the same symmetry conductor 60. The difference is that the amplitude of the output voltages are nominal for a selected utility service and do not change when the utility voltages change.
Examples of Conditioner Operation With Different Utility Services, FIGS. 5-8
FIG. 5A shows a functional diagram of the conditioner of the present invention with a dual phase service of 120 or 240 degrees phase shift between phases and with common grounded conductor, neutral. Blocks 501 and 502 represent input voltage utility sources, phases X and Y, respectively. Block 503 in FIG. 5A represents the conditioner of the present invention. Within block 503, blocks 504 and 505 represent the output load voltage sources for phases X and Y, respectively.
Because all voltages are of the same frequency and sinewave, phase diagrams shown in FIGS. 5B and 5C are used to explain the operation. Phase diagrams for 120 and 240 degrees phase shift cases are shown in FIGS. 5B and 5C, respectively. Because there is a grounded common conductor which is tied to ground, output voltages on phases X and Y are referenced to ground and have nominal phase voltage versus ground potential. FIG. 5B shows voltages 501-1 and 502-1 for utility voltages for phases X and Y, respectively, shown 120 degrees apart. Similarly, the output voltages 504-1 and 505-1 for phases X and Y, respectively, are 120 degrees apart. In FIG. 5C, input utility voltages 501-2 and 502-2 for phases X and Y, respectively, are 240 degrees apart. The same condition is shown for output voltages 504-2 and 505-2.
Although not specifically shown, it is self evident from FIG. 1 that if the phase difference between utility phases X and Y is 180 degrees, i.e., split phase service, the output phases also will be in split phase configuration, with grounded common conductor, and each phase voltage having potential with respect to ground equal to a nominal utility phase voltage.
FIG. 6A shows a functional diagram of the conditioner of the present invention with a dual phase service without use of common grounded conductor. As in FIG. 5A, blocks 601 and 602 represent utility voltage sources for phases X and Y, respectively. Block 603 represents the conditioner of the present invention, with load voltage sources 604 and 605 for phases X and Y, respectively.
Phase diagram FIG. 6B shows two phase voltages referenced to ground. The voltage between phases is applied on the input of the conditioner. If nominal phase voltages are 120 V, then voltage between phases is 208 V. The symmetry conductor voltage with respect to any phase conductor is one half between phase voltage. The output phases 604-1 and 605-1 are in phase with half of the input utility phase vectors (shown as Vin/2 in FIG. 6B), the voltage input utility phases X and Y shown as 601-1 and 601-2. Their nominal value setting is a half of the voltage between phases, 104 V each in case of 208 V between input phases nominally. The voltage between each output phase to ground is the same as nominal utility phase voltages.
FIG. 7A shows the functional diagram of the conditioner of the present invention, with operation from split phase service without use of the the grounded conductor. Again, input voltage sources 701 and 702 are shown for phases X and Y, respectively. In this example, each phase has one half the input utility voltage, and is represented as Vin/2. Block 703 shows the conditioner of the present invention, with output load voltage sources 704 and 705 for phase X and Y, respectively.
The input/output voltage phase diagram is shown in FIG., 7B. Split phase voltages 701-1 and 701-2 are of equal value and are 180 degrees phase shifted with respect to a common grounding conductor. The voltage between phases is double the phase voltage. This double phase voltage is applied to the conditioner input.
The conditioner operates in such a way that the voltage on the symmetry conductor is a half of the input voltage in amplitude and, because of this, makes the potential of the symmetry conductor equal to the common grounded conductor (neutral) of the utility service.
Output phases are the same as voltages between each conditioner input utility phase with respect to the symmetry conductor, only amplitudes are regulated. Phase diagram 7B shows that each output phase voltage will have potential with respect to ground equal to the utility phases at nominal values.
FIG. 8A shows a functional diagram of the conditioner of the present invention connected to a utility service having a single phase, with one power conductor grounded. FIG. 8B is a phase diagram showing phase voltages on the input and output.
The conditioner makes its symmetry conductor to have a potential equal to half the input utility phase voltage (801). Two output phases X and Y (803, 804) are the same as two input phases X and Y with respect to a symmetry conductor with the exception that their amplitude is regulated.
The voltage on phases X and Y on the output with respect to ground are:
V.sub.load X =V.sub.nom /2 +V.sub.util /2
V.sub.load Y =V.sub.nom /2+V.sub.util /2
If the utility voltage is nominal, then the potential of phase Y to ground is zero, similar to the utility phase Y on the input. And the phase X to ground or to phase is equal to the utility nominal voltage similar to the utility service voltage 801.
If the utility voltage differs from nominal, then the phase potential to ground will be equal to half the difference between the utility service voltage and its nominal value. Therefore, the phase Y voltage to ground will not be zero, similar to the utility service phase if it were grounded. If the utility service varies within a wide range of 20% of the nominal value, output phase Y voltage to ground will vary within 10% of the nominal value. The voltage of phase X to ground will be equal to the average utility service voltage, and its nominal value, which is always smaller than the maximum possible value of the input utility phase X voltage, because the maximum value is larger than the nominal value.
In this mode of operation, there is a common mode voltage on the output equal to a half of the difference between input and nominal output voltages. This voltage is similar in value compared to voltages existing on common/neutral conductor of electrical services, and is sinewave in nature, so there are no high frequency harmonics causing malfunctions in connected loads or safety related affects.
FIG. 8B shows input voltages as Vin/2 and output voltages 803-1 and 804-1 for phases X and Y, respectively. The output voltages 803-1 and 804-1 are 180 degrees apart and each has a voltage which is one half the nominal input voltage, represented as Vin nom/2. Therefore, the output voltage, Vout, is equal to the nominal input voltage, Vin nom.
While the present invention has been disclosed with respect to a preferred embodiment and modifications thereto, further modification will be apparent to those ordinarily skilled in the art within the scope of the claims that follow. Therefore, it is not intended that the invention be limited by the disclosure, but instead that its scope be determined entirely in reference to the claims which follow. | An apparatus is disclosed which is capable of conditioning any of a variety of utility service AC power inputs having distortion and noise into a clean AC power signal at the output by using symmetrical topology. The present invention is capable of maintaining a constant voltage amplitude at the output while the input utility voltage amplitude varies, and attenuates any distortions present at the input. The present invention first comprises a boost converter comprised of four semiconductor switches in parallel with a diode bridge to convert the incoming AC signal into a DC signal which is stored on two storage capacitors. Secondly, using a buck inverter, the stored DC signal is reconverted into a clean AC signal applied to the output. Input and output filters are used to help clean the signal, and chokes are used to help separate damaging signals produced by the converter and inverter from the storage capacitors. Appropriate control circuits for operating the semiconductor switches in the boost converter and buck inverter are also disclosed. | 8 |
BACKGROUND OF THE INVENTION
The present invention relates generally to devices for directing airflow to an object and, more particularly, to devices for directing air propelled by an impeller through a housing and into a motor.
BACKGROUND ART
An impeller for moving air, such as may be used in a vacuum cleaner, is often enclosed within a housing which directs air downstream from the impeller as exhaust or for particular uses. For instance, if the impeller is driven by an electric motor, it may be desirable to direct the air moved by the impeller through the interior of the motor for cooling. The design of such a housing, including any vanes which might be used to direct the air, is of critical importance. A properly designed housing can add not only to the efficiency of the system in moving air and increasing air pressure, but can also minimize noise caused by the air flow.
Several patents disclose air directing elements of air moving systems having vanes with uncommon shapes in an effort to increase efficiency or reduce noise. U.S. Pat. No. 4,669,952 discloses a quiet by-pass vacuum motor having a fan end bracket with separating wedges or members which extend from an outer wall to an inner wall and define passageways to exhaust openings. Each wedge has what appears to be a generally radiused curve near the inner wall which flattens out towards the outer wall. The portion of the wedge near the outer wall is thickened as compared to the portion of the wedge near the inner wall.
U.S. Pat. No. 4,859,144 discloses a motor fan system having a non-rotatably mounted interstage and afterstage. Circumferential portions of the vane walls of the interstage and afterstage are turned relative to inner portions such that the walls of the circumferential portions face axially and the inner portions face radially. Junctions between the inner portions of the vanes and a base wall form sharp corners.
In addition to stationary vanes within housings, several patents disclose unusually shaped vanes on impellers or other moving parts. For instance, U.S. Pat. No. 3,398,866 discloses an impeller for a dishwasher pump where the vanes of the impeller are spaced unequally about the impeller. Similarly, U.S. Pat. No. 3,006,603 discloses irregularly spaced blades on a turbine. However, these patents do not disclose or suggest that the vanes may be stationarily disposed within a housing.
SUMMARY OF THE INVENTION
In accordance with one aspect of the present invention, a housing for directing air to an object has a main body portion including a first plurality of ports spaced about a periphery thereof and an outer rim surrounding the main body portion. A base portion extends between the main body portion and the outer rim. A second plurality of vanes is carried on the base portion and each vane extends from the outer rim to one of the ports on the periphery of the main body portion wherein the vanes are spaced in a non-symmetric fashion about the main body portion.
The housing may have an even number of vanes and each vane has a corresponding vane located 180° around the housing. There may be eight vanes on the housing.
Each vane has a port-facing side and the port-facing side may be curved to direct air towards the port adjacent the vane. The port-facing side of each vane may intersect the base portion at a right angle. The port-facing side of each vane may also be nearly tangent to the rim where the port-facing side of the vane extends to the rim.
Each vane has a back-facing side which intersects the main body with a curved surface. The back-facing side may intersect the outer rim with a curved surface and may intersect the base portion with a curved surface to direct air away from the back-facing side.
Further, the outer rim may intersect the base portion with a curved surface to direct air away from the rim and the vanes may be formed integrally with the main body portion, the base portion and the outer rim.
Still further, the housing may be used in combination with a foam ring placed adjacent the vanes.
In accordance with another aspect of the invention, a housing has a main body portion including a first plurality of ports spaced about a periphery thereof, an outer rim surrounding the main body portion and a base portion extending between the main body portion and the outer rim. A second plurality of vanes is carried on the base portion and each vane extends from the outer rim to one of the ports on the periphery of the main body portion. Each vane has a port-facing side, which is curved to direct air towards the port adjacent the vane, and the port-facing side of each vane is nearly tangent to the rim in the area where the port-facing side of the vane extends to the rim.
In accordance with another aspect of the present invention, a housing has a main body portion including a first plurality of ports spaced about a periphery thereof, an outer rim surrounding the main body portion and a base portion extending between the main body portion and the outer rim. A second plurality of vanes is carried on the base portion and each vane extends from the outer rim to one of the ports on the periphery of the main body portion wherein each vane has a port-facing side which intersects the base portion at a right angle. Each vane has a back-facing side and the back-facing side intersects the main body with a curved surface.
In accordance with yet another aspect of the present invention, a housing has a main body portion including a first plurality of ports spaced about a periphery thereof, an outer rim surrounding the main body portion and a base portion extending between the main body portion and the outer rim. A plurality of vanes is carried on the base portion and each vane extends from the outer rim to one of the ports on the periphery of the main body portion wherein each vane has a back-facing side which intersects the outer rim with a curved surface.
In accordance with still another aspect of the present invention, a housing has a main body portion including a plurality of ports spaced about a periphery thereof, an outer rim surrounding the main body portion and a base portion extending between the main body portion and the outer rim. A second plurality of vanes is carried on the base portion and each vane extends from the outer rim to one of the ports on the periphery of the main body portion wherein the vanes are spaced in a non-symmetrical fashion about the main body portion. Each vane has a port-facing side and a back-facing side wherein the port-facing side is curved to direct air towards the port adjacent the vane. The port-facing side of each vane also intersects the base portion at a right angle and is nearly tangent to the rim in the area where the port-facing side of the vane extends to the rim. The back-facing side intersects the main body, the outer rim and the base portion with curved surfaces. The outer rim intersects the base portion with a curved surface to direct air away from the rim.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a bottom view of a motor assembly incorporating the motor housing of the present invention;
FIG. 2 is a side elevational view, partially in section, of the motor assembly of FIG. 1;
FIG. 3 is a bottom view of the motor housing of the present invention;
FIG. 4 is a plan view of the motor housing of FIG. 3;
FIG. 5 is a bottom view of the impeller of FIG. 2., shown partially in phantom;
FIG. 6 is a sectional view, taken generally along the lines 6--6 of FIG. 4;
FIG. 7 is a sectional view taken generally along the lines 7--7 of FIG. 4;
FIG. 8 is an exploded perspective view of a portion of the motor assembly of FIG. 1.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring initially to FIGS. 1 and 2, a motor assembly indicated generally at 20 has a motor 22 that rotates a drive shaft 24. The drive shaft 24 is connected to an impeller 26 by a spacer 27, washers 28A and 28B and a nut 29. The impeller 26 draws air through an opening 30 in a lower housing 32 (FIG. 1) and directs the air radially outward. Air directed by the impeller 26 flows around the outside of a baffle plate 34 through a foam ring 36 and into an upper housing 38. As will be discussed further below, air in the upper housing 38 is directed radially inward by features of the upper housing 38 and into the motor 22. The air may be used to cool the motor 22 and comprise working air for a dry vacuum cleaner.
Referring now to FIG. 8, the lower housing 32 has a sidewall 40 which is secured to the upper housing 38 by means of interengaging projections and mating recesses or dimples (not depicted). The impeller 26, shown in additional detail in FIG. 5, has a lower wall 42 and an upper wall 44. Lower wall 42 has a large circular opening 46 through which air enters the impeller 26 from the opening 30 in the lower housing 32. The upper wall 44 has an opening 48 through which the spacer 27, the washers 28A-B and the nut 29 (FIG. 2) attach the drive shaft 24 to the impeller 26 for rotation. The impeller 26 has several curved vanes 50 A-F located between the lower wall 42 and upper wall 44. When the impeller 26 rotates in a counter-clockwise direction as shown in FIG. 8, air entering through the opening 46 is moved by the vanes 50A-F radially outward.
The baffle plate 34 has an opening 52 through which drive shaft 24 passes. Holes 54A-D permit screws 56A-D to pass through baffle plate 34 for attachment on the upper housing 38. The foam ring 36 is located between the baffle plate 34 and the upper housing 38. The baffle plate 34 has a diameter slightly less than the diameter of the upper housing 38 (see FIG. 2) so that air can pass around the baffle plate 34 and into the upper housing 38.
The upper housing 38 includes a main body 58 having an opening 60 surrounded by an offset ring 61 through which drive shaft 24 passes so that the drive shaft 24 is able to rotate without imparting torque to the upper housing 38. Ball bearings (not depicted) may be provided above the offset ring 61, surrounding the drive shaft 24 to facilitate the rotation of the drive shaft 24. In a sidewall 62 of the main body 58 are ports 64A-H, some of which extend well into the top portion of the main body 58. Preferably, the ports 64A-H are equal in size to optimize performance and reduce noise levels. Around the outside of the housing 38 is a rim 66 which is connected to the main body 58 by a base 68.
As can be seen from FIG. 4, the back of upper housing 38 has a number of features on the main body 58 which provide strength or allow the upper housing 38 to attach or mate with the motor 22. Thus, the precise shape of the back of upper housing 38 will be dependent upon the motor used. Threaded openings 67A and 67B are provided to bolt the upper housing 38 to the motor 22. Baffles 65A and 65B help direct air into the center of the motor instead of allowing it to pass along the outside of the motor. In addition, the back of the upper housing 38 has six projections 69A-F which prevent air from merely spinning around in the area inside of the ports 64A-H, but instead forces the air axially into the motor 22.
Referring now to FIG. 3, each port 64A-64H of upper housing 38 has a vane 70A-H associated therewith. The vanes 70A-H are not located symmetrically about the upper housing 38, but are instead placed at varying distances or angular positions about the rim 66 and the main body 58. Each vane 70A-H extends from the main body 58 to the rim 66 and is attached to the base 68. Although the vanes 70A-H are not located symmetrically about the upper housing 38, each vane has a corresponding vane located 180° around the upper housing 38, i.e., vane 70A corresponds to vane 70E, vane 70B corresponds to vane 70F, vane 70C corresponds to vane 70G, and vane 70D corresponds to vane 70H. Thus, the angle between adjacent vanes is identical to the angle between the respective corresponding adjacent vanes 180° away. Preferably, the angle between vane 70A and vane 70B or between vane 70E and vane 70F is 37°, the angle between vane 70B and vane 70C or between vane 70F and vane 70G is 58°, the angle between vane 70C and vane 70D or between vane 70G and vane 70H is 32°; and between vane 70D and vane 70E or between vane 70H and vane 70A is 53°. All angles are measured from the side of each port nearest its vane to the side of the adjacent port nearest its vane. It is believed that placing vanes in a nonsymmetrical fashion, which presents unevenly spaced obstacles for flowing air, reduces constant and even whistling, thereby reducing noise while minimizing any loss in efficiency.
Each vane 70A-70H, for example the vane 70H, has two sides, a port-facing side 72 and a back-facing side 74. The port-facing side 72 has an arcuate or curved shape so as to direct air from each vane 70A-H to its associated port 64A-H. The arcuate shape of the port-facing side 72 of each vane 70A-H allows the port-facing side 72 to intersect the rim 66 substantially tangentially at a portion 76. The substantially tangential intersection of the port-facing side 72 and the rim 66 allows air to be guided inwardly with the smoothest possible flow, which increases performance and keeps noise levels low.
The back-facing side 74 of each vane 70 does not follow the contour of the port-facing side 72, and thus each vane 70 is of varying thickness as it extends from the main body 58 to the rim 66. The back-facing side 74 of each vane 70 intersects the main body 58 with a curved surface 78 to direct air towards the port-facing side 72 of an adjacent vane. Similarly, the back-facing side 74 intersects the rim 66 with a curved surface 80 to direct air away from the back-facing side 74 and towards the port-facing side 72 of an adjacent vane. In essence, vanes of an essentially uniform thickness throughout their length have been widened at each end or have had their intersections filled in with material to replace sharp corners which would otherwise be present where the vanes meet the remainder of the housing. It is believed that sharp corners contribute to whistling or noise when air is pulled across them and may also reduce the efficiency of the lower housing 38 in allowing air to pass therethrough. In addition to the curvatures of the surface 78 and the surface 80, the back-facing side 74 may also have a gentle arcuate shape between the surface 78 and the surface 80, where the curvature is in the same direction as the curvature of the port-facing side 72.
Referring now to FIGS. 6 and 7, the base 68 intersects the rim 66 with a curved surface 82 to direct air away from the rim and towards an adjacent port. Similarly, the back-facing side 74 of each vane intersects the base 68 with a curved surface 84 to direct air away from the back-facing side 74. The port-facing side 72 of each vane, however, intersects the base 68 at a corner 86 which is nearly at a right angle. By providing a sharp corner, a recirculation condition, in which air flows over vanes or ports without exiting, is minimized.
The rim 66 has a flange 88 running around its perimeter to seat the lower housing 32 when it is snapped in place on the upper housing 38.
The specific size of the upper housing 38 will depend upon the amount of air to be moved and the motor with which it is used, however, the following dimensions relative to each other are suitable for an embodiment of the housing and other parts associated therewith. The diameter of the housing measured from the outside of flange 88 is 5.78 inches (14.68 cm). The diameter of the outside portion of the rim 66 is 5.64 inches (14.33 cm) with a thickness of the rim of 0.09 inches (0.23 cm). The height of the entire main body 38 is 1.10 inches (2.79 cm) and the distance from the back of the main body 38 to the top of the rim 66 is 0.97 inches (2.46 cm). The width of each port 64 is 0.40 inches (1.02 cm). The thickness of the base portion 68 is 0.12 inches (0.30 cm) and the height of each vane 70 is 0.425 inches (1.08 cm). The height of each vane 70 with respect to other elements of the lower housing 38 is particularly critical for reducing noise and increasing efficiency.
As noted above, many of the elements of the upper housing 38 are arcuate in shape or intersect other elements arcuately. Suitable radii of curvature for the elements are as follows:
______________________________________Element Radius of Curvature______________________________________port-facing side 72 1.00 inch (2.54 cm)back-facing side 74 1.07 inches (2.72 cm)curved surface 78 .50 inches (1.27 cm)curved surface 80 .22 inches (.56 cm)curved surface 82 .25 inches (.64 cm)curved surface 84 .06 inches (.15 cm)______________________________________
The upper housing 38 may be made of Plenco 1581 I, Polyester Mineral, reinforced with glass, or may be made from any other suitably rigid material such as zincs, aluminums or other plastic materials. The vanes 70A-H are preferably formed integrally with the rest of the upper housing 38 and are of the same material.
The foam ring 36 may be 0.25 inches (0.64 cm) thick, have an outside diameter of 5.40 inches (13.7 cm) and an inside diameter of 4.00 inches (10.16 cm). The foam ring 36 may be made of a ester type polyurethane foam which is reticulated and has 10 open pores per linear inch.
The lower housing 32 may have an outside diameter of 5.64 inches (14.33 cm), with a diameter of the opening 30 of 1.730 inches (4.39 cm). The overall height of the lower housing 32 may be 1.088 inches (2.76 cm) with the height from the rim of opening 30 to the top of lower housing 32 being 0.803 inches (2.04 cm). The baffle plate 34 has an overall thickness (including the curved edge portion) of 0.100 inches (0.25 cm) and a material thickness of 0.024 inches (0.06 cm). The diameter of the baffle plate 34 is 5.22 inches (12.26 cm). The impeller 26 has a total thickness of 0.29 inches (0.74 cm) with the thickness of lower wall 42 and upper wall 44 of 0.020 inches (0.051 cm). The height of each vane 50 is 0.25 inches (0.64 cm) and has a radius of curvature of 1.625 inches (4.13 cm). Opening 46 has a diameter of 1.875 inches (4.76 cm). The impeller is designed to rotate at 17,000 to 30,000 revolutions per second.
Numerous modifications and alternative embodiments of the invention will be apparent to those skilled in the art in view of the foregoing description. Accordingly, this description is to be construed as illustrative only, and is for the purpose of teaching those skilled in the art the best mode of carrying out the invention. The details of the structure may be varied substantially without departing from the spirit of the invention, and the exclusive use of all modifications which come within the scope of the appended claims is reserved. | A housing for directing air propelled by an impeller through an object such as a motor has several arcuate vanes which direct the air radially inward towards ports associated with each vane. The vanes of the housing are placed non-symmetrically about the housing, and each vane has a corresponding vane located 180° around the housing. Sharp corners are eliminated on the back of each vane where the vane meets a main body, where each vane meets an outer rim and/or where each vane meets a base portion of the housing. The disclosed housing increases efficiency in moving air while decreasing the noise of the airflow. | 0 |
FIELD OF THE INVENTION
[0001] The present invention relates to a method for accurate positioning of a small object to be secured at a specific place. The present invention also provides a device and kit for positioning such an object. The present invention further provides a method for positioning a dental restoration on a tooth, and more particularly relates to the use of a placement device for the positioning of a dental restoration on a tooth.
BACKGROUND OF THE INVENTION
[0002] There are many situations in life that require the accurate placement of small objects. Generally the accurate placement of a small object is hindered by a user's hands and an inability to control their grip and/or release on an object at a specific position. Examples of such situations include modelling and craft applications, i.e scrap booking and jewellery making.
[0003] One situation that requires the accurate placement of a small object occurs in the dental field. Conventional techniques to secure inlays, onlays, crowns and veneers (dental restorations) have depended upon various rod-like handles tipped with sticky wax or nectar-like bulbs. These techniques are generally limited in their effectiveness due to their weak and unpredictable bond. Since the restoration once “held” by such handles is subject to multiple manipulations prior to final placement the tenuous bond provided by present alternatives is often stressed to the point of failure. The placement of these small dental restorations is the culmination of much effort and it is crucial that the grip described is reliable but also easily removable once final placement is achieved.
[0004] Different options have been discussed in the dental community to overcome some of the problems of the known methods discussed above. It is generally acknowledged that existing products are inadequate. One suggestion advanced has been to use a light cured bonding agent normally used to bond standard dental composite restorations. The technique suggested has been to bond a brush unto the restorative surface. This technique provides a more stable bond than other presently marketed techniques but is time consuming, requires two people to perform, and is not cost effective. The brush is also often difficult to remove after placement and residual bond left behind on the restoration is clear and hence difficult to see. Its complete removal after requires the use of a dental drill, which can mar the previously polished or glazed finish.
[0005] Thus, there is a need for an improved method and for a device useful for object positioning.
SUMMARY OF THE INVENTION
[0006] Such a device and method have now been developed.
[0007] Thus, in one aspect, the present invention provides a method of positioning a dental restoration, having an interior surface and an exterior surface, on a tooth, comprising the steps of (i) placing on the exterior surface of the dental restoration at least one glue pellet, (ii) applying heat to the at least one glue pellet to melt the glue pellet; (iii) positioning an end portion of a restoration placement device into the melted glue pellet and thereby receiving the glue pellet thereon; (iv) applying a tooth bonding material to the interior surface of the dental restoration; (v) positioning the dental restoration on the tooth; and (vi) removing the restoration placement device from the restoration.
[0008] In one embodiment, the step of applying a heat source to the at least one glue pellet uses a portable heat source. In a further embodiment, the at least one glue pellet is dispensed from a spring-loaded glue pellet cassette, or from a cassette comprising multiple pellet-containing compartments. In an alternative embodiment, the restoration placement device comprises a plurality of bristles extending outwardly from the end portion.
[0009] In an additional aspect, the present invention provides a method of mounting a dental restoration onto a restoration placement device comprising the steps of (i) placing on the exterior surface of the dental restoration at least one glue pellet; (ii) applying heat to the at least one glue pellet to melt the glue pellet; and (iii) positioning an end portion of the restoration placement device into the melted glue pellet.
[0010] In a further aspect, the present invention provides a dental restoration placement device comprising a handle portion and a substantially flat head portion connected to one end of the handle portion, said head portion comprising a plurality of bristles extending therefrom, the head portion being operable to bend relative to the handle portion and having sufficient bristles operable to extend into and secure onto molten glue. The present invention also provides for the use of the dental restoration brush described herein.
[0011] In a further aspect, the present invention provides a dental restoration kit comprising a placement device having a head portion comprising a plurality of bristles extending therefrom and at least one glue pellet sized to receive the head portion of the placement device when in a molten state.
[0012] In an alternative embodiment, the present invention provides a dental restoration kit comprising a placement device having a head portion comprising a plurality of bristles extending therefrom, a glue pellet cassette, comprising a plurality of glue pellets, operable to dispense individual glue pellets and a portable heat source operable to melt a glue pellet.
[0013] In an alternative embodiment, the present invention provides a placement device comprising a handle portion and a head portion, connected to one end of the handle portion, the head portion being operable to bend relative to the handle portion and being of sufficient size to extend into and secure onto molten glue. The present invention also provides for the use of the dental restoration device described herein. In one embodiment, the head portion comprises a plurality of bristles extending therefrom which are operable to extend into and secure a molten glue pellet.
[0014] In a further aspect, the present invention provides an adhesion kit comprising a placement device having a flexible handle portion and a head portion and at least one glue pellet sized to receive the head portion of the placement device when the glue pellet is in a molten state. The placement device may also include a plurality of bristles extending from the head portion thereof.
[0015] In an alternative embodiment, the present invention provides an adhesion kit comprising a placement device having a head portion comprising a plurality of bristles extending therefrom, a glue pellet cassette, comprising a plurality of glue pellets, operable to dispense individual glue pellets and a portable heat source operable to be received by at least one glue pellet and to apply heat thereto. The glue pellet cassette is operable to releasably attach to the heat source.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] The invention will be described below in further detail with particular reference to the accompanying drawings in which:
[0017] FIGS. 1 through 3 are photographs of a portable heat source that may be used in the present invention;
[0018] FIG. 4 is a photograph of one embodiment of a dental placement device that may be used in the present invention;
[0019] FIG. 5 is a photograph of an alternative embodiment of a dental placement device that may be used in the present invention;
[0020] FIG. 6 is a photograph of a portable heat source attached to a glue pellet:
[0021] FIG. 7 is a photograph of a dental restoration including a molten glue pellet thereon;
[0022] FIG. 8 is a photograph of a dental placement device being positioned adjacent the dental restoration illustrated in FIG. 7 ;
[0023] FIGS. 9 and 10 are photographs of a dental placement device positioned in the molten glue on the dental restoration illustrated in FIG. 7 ;
[0024] FIG. 11 illustrates the removal of a glue pellet form a dental restoration using a dental placement device according to the present invention;
[0025] FIG. 12 illustrates the connection of an alternative embodiment of a dental placement device with a glue pellet according to the present invention; and
[0026] FIGS. 13 and 14 illustrate one embodiment of a glue pellet cassette according to the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0027] The present invention provides a device and kit, and a method of using the device and/or kit, for positioning and maintaining objects in a required place and, in particular, objects that are to be adhered to a surface. For example, the method and device and/or kit may be used to position an object in a craft project to a surface, such as a jewel to a costume. Alternatively the device and/or kit may be used by a dentist to position a dental restoration on a tooth. The present method and device are particularly useful to position an object in a location that is generally difficult to otherwise access.
[0028] The present invention provides a user with a tool that allows for easy and precise placement of an object at a desired position. In particular, the invention allows a user to place a small object at a precise location while only requiring the use of one hand.
[0029] The present invention will be described in further detail in relation to the dental application. However, it will be understood that this embodiment is not meant to be limiting for the use of the device and/or kit.
[0030] Thus, in one embodiment, the present invention provides a method for positioning a dental restoration on a tooth. It will be understood by a person skilled in the art that a dental restoration may include inlays, onlays, crowns, veneers and the like.
[0031] The present invention includes the use of a dental placement device, or microbrush, that is illustrated in FIG. 4 at numeral 10 . The dental placement device of the present invention includes a handle portion 12 and a head portion 14 . A stem 13 fastens the head portion 14 to the handle portion 12 at connection point 15 . As can be clearly seen in FIG. 4 , the head portion 14 is flexibly attached to the handle portion 12 and is operable to rotate, bend and/or flex about the connection point 15 to assist the user with the correct positioning of a dental restoration as well as to assist in the removal of the device and glue from the restoration, described below in further detail, following placement of the restoration.
[0032] In one embodiment, shown in FIG. 4 , the head portion 14 includes a plurality of bristles 16 extending therefrom. The bristles 16 are sized and positioned in order to be operable to spread out into molten glue when in use. The ability of the bristles 16 to extend outwardly provides secure attachment to the molten glue when in use, allowing the user to remove the glue with the brush when required, described in further detail below.
[0033] In an alternative embodiment, shown in FIG. 5 , the head portion 14 is substantially flat and does not include bristles, however the profile of the head portion 14 is sufficient to provide an effective surface for attachment of the head portion to the molten glue, as seen in FIGS. 8 and 9 . As will be appreciated by one of skill in the art, the head portion 14 may be otherwise shaped, including for example, round or oval.
[0034] As one of skill in the art will appreciate, the placement device is made of materials conventionally used for similar such devices, for example, metals, hard plastics, rubber, etc., which are appropriate to permit the device to function. For a dental placement device, the materials will, of course, be suitable for use of the device in the mouth of a patient. In addition, the components of the device, such as the head portion and the handle portion, may be made of the same materials or different materials. In this regard, the handle and head portions of the device may be unitary in construction, or may be distinct components that fit together to form the device.
[0035] The method for positioning a dental restoration on a tooth includes the initial step of placing at least one glue pellet 18 on the exterior surface of the dental restoration 20 . It will be understood that the term “exterior surface” means the surface that will face outwardly when the dental restoration is placed on the tooth. In a preferred embodiment, only one glue pellet 18 is required and the pellet is sized such that when it is in the molten state it is received on the surface of the restoration 20 and, as can be seen in FIG. 7 , covers a portion of the surface of the restoration sufficient to provide a secure connection to the placement device 10 to allow for easy control and placement by the user. In one embodiment, pellets of varying sizes are provided for use with dental restorations of different size. In this embodiment, the pellets may be of different colours, including being clear, each colour representing a different size to allow a user to easily choose the preferred size.
[0036] In a preferred embodiment the pellets 18 are disc shaped and include a perforation in the centre. The perforated centre allows for the placement of a heating device 22 , shown in FIGS. 1-3 , within the centre to pick up the disc and move to the required position. Preferably the discs are 1-2 mm thick and have a diameter of 3-4 mm.
[0037] In a further embodiment, a glue pellet cassette 24 , shown in FIGS. 13 and 14 , is provided for easy dispensing of the glue pellets. The cassette is spring-loaded and allows a user to remove one pellet at a time through an aperture that is opened by a dispensing mechanism in a manner known in the art. Alternative dispensing cassettes may also be used, as will be appreciated by one of skill in the art. In another example, a cassette comprising multiple pellet-containing compartments may be used including a rotatable dispensing mechanism, or a rotatable cover with a window opening allowing a single compartment only to be open to release the desired glue pellets. The glue pellet cassette 24 may also be operable to connect to a portion of the surface of the portable heating device 22 . For example, the cassette 24 may include a groove or clip that allows attachment to the portable heating device 22 handle for convenient storage and transport.
[0038] Once the glue pellet 18 has been positioned on the dental restoration, a heating device 22 , for example a portable heating device 22 as seen in FIG. 6 , is used to apply heat to the glue pellet 18 and melt the glue pellet 18 . In one embodiment, the heating device 22 is a portable heating device, such as a soldering unit or a laser or electro surgical unit. Preferably the portable heating device 22 is a portable battery operated soldering unit. The heating device 22 will be activated for a time sufficient to turn the glue pellet 18 into a liquid globule. It will be understood that a person skilled in the art will know the time required to apply heat using the heating device or source to achieve the desired molten state of the glue. A suggested time for applying the heat using the heat source is approximately 5 seconds. Heating time can be varied to alter the degree of adhesion.
[0039] Once the heat has been applied and the glue is in a sufficient molten or liquid state, the heating device 22 is removed from the glue, see FIG. 7 . While the glue is still in a molten state the head portion 14 of the placement device 10 is placed, or plunged, into the liquid glue, as illustrated in FIGS. 8 and 9 . The head portion 14 is positioned to be received in the glue at a position that allows a user to have sufficient control in handling and positioning the restoration, i.e. preferably the head portion is centrally received within the glue. In the embodiment in which the head portion 14 includes bristles 16 , when the head portion 14 is placed into the glue the bristles 16 extend outwardly therefrom into the liquid glue, as seen in FIG. 12 . The position and size of the bristles 16 allow them to spread out into the glue and provide a secure connection between the placement device 10 and the glue. In the alternative embodiment in which the placement device includes a substantially flat head with no bristles, the head portion is received in the molten glue at a position that allows for sufficient connection between the flat head portion and the glue to provide a secure attachment therebetween, as illustrated in FIG. 9 .
[0040] Prior to placement of the restoration on a tooth, a tooth bonding material is applied to the interior surface of the restoration, i.e. the surface of the restoration which comes in contact with the tooth and is seated on the tooth. The tooth bonding material is of the type conventionally used.
[0041] The restoration may then be placed on the tooth where desired. It will be understood that the connection of the restoration to the tooth will be by means known in the art. Once the restoration has been placed on the tooth, the flexible handle of the placement device 10 may be bent, as required, to facilitate final placement of the restoration. Once the final placement has been achieved, the device 10 can be pulled away from the restoration, separating the head portion, including the glue attached thereto, from the restoration as seen in FIG. 11 .
[0042] It will be understood that the glue is readily removed or lifted from the restoration with the placement device due to the secure placement of the head portion within the glue. This secure placement is advantageously enhanced with bristles in the head portion. Any glue remaining on the dental restoration is easily identified by its colour and can readily be removed by peeling the glue from the restoration.
[0043] The use of the invention will clearly be understood by the above embodiment and can be adapted to other situations that require the placement of an object at a specific location, and in particular at a location that requires controlled and accurate placement by a user. For example, in costume jewellery there are generally numerous small jewels and the like the positioning of which require high precision with low tolerance. Many craft and modelling activities require similar levels of glue placement precision. Eliminating the need for proximity to a wall electrical outlet is also an attractive feature provided by a cordless heating element. Such work can be tremendously fiddly requiring accurate control by a designer in placing the jewels at specific locations. The invention provides a tool that can assist. A glue pellet, or portion thereof, may be placed on the jewel to be positioned and then heat can be applied to transform the glue to its molten state. The head of the placement tool may then be placed in the molten glue to adhere the device to the jewel. Once the tool is placed in the molten glue, additional glue may be positioned on the opposite surface of the jewel, or alternatively glue may be placed at the location at which the jewel is to be placed. The user may then position the jewel at the appropriate location using the flexible handle portion to accurately position the jewel. Once in place and adhered on the surface the user can remove the tool with the glue portion from the jewel and continue with the work. It will be understood that this embodiment employs a similar use to that described above.
[0044] While this invention has been described with reference to illustrative embodiments and examples, the description is not intended to be construed in a limiting sense. Thus, various modifications of the illustrative embodiments, as well as other embodiments of the invention, will be apparent to persons skilled in the art upon reference to this description. It is therefore contemplated that the appended claims will cover any such modifications or embodiments. Further, all of the claims are hereby incorporated by reference into the description of the preferred embodiments. | A method, a device and a kit for the positioning of a small object, such as a dental restoration, in a specific desired location is disclosed. Conventional techniques to secure dental restorations have depended upon various rod-like handles tipped with sticky wax or nectar-like bulbs. These techniques are generally limited in their effectiveness due to their weak and unpredictable bond. The present placement device includes a handle portion ( 12 ) and a head portion ( 14 ) comprising bristles ( 16 ). The present method includes the steps of placing a glue pellet ( 18 ) on the exterior surface of the object, applying heat to the pellet to melt it, positioning a head portion ( 14 ) of a restoration placement device having bristles ( 16 ) in the melted glue to receive the object on the end portion of the device, placing the object in its desired location and removing the restoration placement device from the object. | 0 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a blind or camouflage apparatus for mounting to an archery bow. More particularly, the present invention relates to a blind including a sheet of camouflage material having a plurality of cuts defined therethrough forming a corresponding plurality of flaps which simulate foliage and openings which allow clear observation by an archer using a bow to which the blind is mounted.
2. Background of the Prior Art
In the sport of archery hunting, it is common to use a blind in order to conceal the presence and movement of the archer. The blind is typically set up adjacent a game trail and the archer waits behind or within the blind for quarry to happen by. The blind disguises the presence of the archer and also disguises the archer's movements especially when drawing the bow inasmuch as game animals are typically more cognizant of movement then the actual silhouette of the archer.
Some game animals, however, do not necessarily travel along game trails and accordingly the archer must move about in search of the game. In order to avoid detection by the quarry, it is advantageous for the archer to use a portable blind which is desirably coupled to the bow itself in order to effectively camouflage the silhouette of the archer and the bow, and to camouflage the movements of the archer, bow, and arrow when the bow is being drawn.
A typical prior art bow-mountable blind includes a sheet of camouflage material, a pair of spaced-apart, elongated parallel rods suspending the camouflage material therebetween, and straps for coupling the rods to the face of the bow. The camouflage material is typically composed of an open-weave fabric having a camouflage pattern imprinted thereon. The material includes a central opening through which the arrow extends. The open-weave nature of the prior art camouflage material is intended to allow the archer to observe the target therethrough while the camouflage pattern prevents the quarry from detecting the archer's silhouette and movement. The open-weave nature of the camouflage sheet, however, prevents clear observation of the target especially in dimly lighted situations. Furthermore, the camouflage pattern imprinted on the material may not be totally natural in simulating foliage and other natural structures.
Additionally, typical print art bow-mountable blinds present an inconvenience in that while traveling, the blind must be detached from the bow to keep it from catching on branches on so forth, and then reattached when game is detected in the vicinity. The delay time encountered in reconnecting the blind to the bow may provide sufficient time for the quarry to escape.
SUMMARY OF THE INVENTION
The present invention solves the problems as outlined above. That is to say, the invention hereof provides for a bow-mountable blind or camouflage apparatus which provides the archer with a clear view of the target, more naturally simulates foliage and the like, and is quickly shifted to a collapsed position during travel and just as quickly extended to an extended position for effective use.
The preferred bow-mountable blind includes a camouflage unit having a sheet of flexible camouflage material and support structure for coupling with the sheet, and means for attaching the unit to the bow. The camouflage sheet includes structure defining a plurality of separate cuts therethrough forming a plurality of integral flaps and a corresponding plurality openings through the sheet. The flaps, when extended away from the openings, simulate leaves and enhance the camouflage effect of the sheet. The preferred support structure includes a pair of elongated, spaced-apart, parallel support members supporting the camouflage sheet therebetween. The support members each include shifting means for allowing selective respective shifting of the members between an extended position in which the members are generally transverse to the long axis of the bow, and a collapsed position in which the members are generally aligned with the bow axis.
In preferred forms, each flap presents a base whereby each is connected to the remaining portion of the camouflage sheet and which allows the flap to be folded therealong in order to expose the opening. Each flap also presents a distal portion separated from a opposed portion of the sheet by a respective one of the cuts. Preferably, the flaps are oriented such that a strain placed on the sheet in a direction generally aligned with the long axes of the flaps causes the distal portions to separate from the opposed portions in order to expand the openings.
Other the preferred aspects of the present invention will become clear from the detailed description hereinbelow.
BRIEF DESCRIPTION OF THE DRAWING FIGURES
FIG. 1 illustrates the bow-mountable blind coupled with an archery bow;
FIG. 2 is a view of the blind hereof with the camouflage sheet in phantom, showing the support members in the extended position, and illustrating the collapsed position thereof in dashed lines;
FIG. 3 is a partial sectional view taken along line 3-13 3 of FIG. 2;
FIG. 4 is a partial elevational view of a pivot structure of one of the support members illustrated in the collapsed position;
FIG. 5 is a plan view of the pivot structure of FIG. 4;
FIG. 6 is a partial elevational view of the camouflage sheet illustrating the cuts forming the flaps of the camouflage sheet with the flaps in place over the openings; and
FIG. 7 is a partial plan view of the camouflage sheet showing the flaps adjusted to simulate foliage leaves and showing the openings exposed thereby.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
With reference to the drawing figures, preferred bow-mountable blind 10 broadly includes camouflage unit 12 and attachment structure 14. Camouflage unit 12 broadly includes camouflage sheet 16 and support structure 18.
Camouflage sheet 16 is preferably composed of a rectangular sheet of vinyl presenting opposed faces with each face having a different camouflage pattern imprinted thereon. The reversible and replaceable nature of the sheet 16, as will be explained further hereinbelow, allows the archer to select the camouflage pattern most effective for the season, terrain, and surroundings.
Turning now to FIG. 6, camouflage sheet 16 includes a plurality of chevron-shaped cuts 20 defined therethrough. Cuts 20 are arranged in a plurality of rows with the cuts in each row being oriented in the same direction. The cuts in adjacent rows are oriented in the opposite direction to produce the cut pattern as shown in FIG. 6.
Each cut 20 in camouflage sheet 16 forms a respective flap 22 covering a corresponding respective opening 24 (see FIGS. 1 and 7).
Each flap 22 presents base portion 26 whereby each flap 22 is coupled with the remaining portion of camouflage sheet 16, and a distal portion 28 opposite base portion 26. Cuts 20 also form opposed portions 30 which is that portion of sheet 16 adjacent a respective cut and opposite a corresponding distal portion 28. That is to say, distal portions 28 are separated from their corresponding opposed portions 30 by respective cuts 20.
In use, and when a strain is placed on camouflage sheet 16 in a direction parallel to the respective long axes of flaps 22, that is, in a direction parallel to the directions in which cuts 20 point, distal portions 28 separate from opposed portions 30 thereby expanding openings 24.
In preferred use, flaps 22 are randomly folded along respective base portions 26 to present the appearance of foliage leaves as illustrated in FIGS. 1 and 7 and to expose openings 24. That is to say, flaps 22, when folded outwardly from the face of camouflage sheet 16, effectively simulate leaves which enhances the camouflage effect of the camouflage pattern imprinted on sheet 16.
Camouflage sheet 16 also presents respective upper and lower edges 32 and 34. The fabric adjacent edges 32, 34 is preferably sewn, or additional fabric added, to form respective pairs of support sleeves 36a,b and 38a,b associated with each edge 32, 34. That is to say, upper sleeves 36a,b are aligned and centrally spaced-apart adjacent upper edge 32, and lower sleeves 38a,b are aligned and centrally spaced-apart adjacent lower edge 34. Sleeves 36a,b and 38 a,b are used to couple with support structure 18 for support of camouflage sheet 16.
Support structure 18 includes upper and lower elongated support members 40 and 42. Members 40, 42 are preferably composed of lightweight wood, synthetic resin material, or lightweight metal such as aluminum as a matter of design choice.
Upper support member 40 includes center section 44 and respective left and right end sections 46a,b. Similarly, lower support member 42 includes lower center section 48 and respective lower end sections 50a,b.
Support structure 18 includes shifting means preferably embodied as upper and lower pivot structures. Upper pivot structures 52a,b respectively couple the inboard ends of upper end sections 46a,b with the respective outboard ends of upper center section 44. Similarly, lower pivot structures 54a,b respectively couple the inboard ends of lower end sections 50a,b with the respective outboard ends of lower center section 48.
FIG. 4 and 5 illustrate pivot structure 52a which is typical of all four pivot structures. In FIGS. 4 and 5, upper end section 46a is illustrated in the collapsed position of blind 10 which will be explained further hereinbelow.
Conventional pivot structure 52a includes leaf spring fixture 56, detent fixture 58, and pivot pin 60. The associated ends of upper center section 44 and upper end section 46 are inset or routed so that they overlap and present respective flush surfaces. Leaf spring fixture 56 is mounted to the recessed end of upper center section 44 and detent fixture 58 is mounted to the recessed portion of upper end section 46a. Pivot pin 60 is configured in a manner similar to a rivet and pivotally joins respective ends of sections 44 and 46a such that when the sections are axially aligned with one another, leaf springs 62a,b, included as part of fixture 56, are respectively received within corresponding detents (not shown) in fixture 58 thereby holding sections 44 and 46a in alignment. In the position shown in FIGS. 4 and 5, the friction fit between pivot pin 60 and the ends of 44 and 46a hold the sections in the positions as shown.
FIG. 2 illustrates blind 10 in the extended position wherein end sections 46a,b and 50a,b are respectively aligned with center sections 44, 48 which results in end sections 46a,b and 50a,b being generally transverse to the long axis of the bow to which blind 10 is attached. The dashed lines of FIG. 2 illustrate the collapsed position for blind 10 in which end sections 46a,b and 50a,b are respectively pivoted about pivot structures 52a,b and 54a,b into general alignment with the long axis of the bow. Thus, pivot structures 52a,b and 54a,b allow selective shifting of support members 40, 42 and thus blind 10 between extended and collapsed positions.
In order to couple camouflage sheet 16 with support structure 18, upper sleeves 36a,b and lower sleeves 38a,b receive upper end sections 46a,b and lower end sections 50a,b respectively. This is best accomplished when the respective end sections are shifted to a position about midway between the extended and collapsed positions. In this midway position, the sleeves can easily be slipped over their associated end sections. Easily removable tape or the like is preferably used to prevent sleeves 36a,b and 38a,b from slipping off respective end sections 46a,b and 50a,b.
With the preferred structure of camouflage sheet 16 support structure 18 as explained above, sheet 16 can be easily removed therefrom and turned around to present the other camouflage face of sheet 16 as desired to more closely match the terrain, foliage, and season. Just as conveniently, other camouflage sheets 16 having different camouflage patterns 16 thereon can conveniently and quickly replace an existing camouflage sheet when desired.
Preferred attachment structure 14 includes a pair of attachment members 64 and 66. Each member 64, 66 includes a respective attachment loop 68, 70 and attachment strap 72, 74. Attachment members 64, 66 are preferably composed of nylon and also have a camouflage pattern thereon. Each loop 68, 70 is designed to respectively loop about center sections 44, 48. Attachment straps 72, 74 are respectively sewn to loops 68, 70 remote from end sections 44, 48 as illustrated in FIG. 2. Straps 72, 74 include respective hook-and-eye fastener strips (such as VELCRO) sewn thereto on opposed faces as illustrated in FIG. 2.
In the use of the bow-mountable blind 10, camouflage sheet 16 is coupled with support structure 18 as explained above. Blind 10 is then coupled with bow 78 by wrapping attachment straps 72, 74 held respectively therearound which are releasably in place by hook-and-eye fasteners 76. When coupled with bow 78, blind 10 presents the configuration as shown in FIG. 1. In this configuration, the movement of an archer therebehind when drawing the bow and the associated movements of the bow string and arrow are effectively camouflaged from view. Flaps 22 enhance the camouflage effect of the camouflage pattern on sheet 16 so that even with openings 24 through sheet 16, the archer and associated movements are still effectively camouflaged. Openings 24 are sufficient in size and number to provide clear observation by the archer of the target thereby allowing for effective aiming.
As those skilled in the art will appreciate, flaps 22, by simulating leaves, provide effective camouflaging movement of the archer even if such movement results in slight movement of blind 10 itself. That is to say, the movement of blind 10 would correspond to natural movement of foliage and leaves and would not be so likely to alert the quarry.
When the archer is ready to move to another location, blind 10 can be quickly shifted to the collapsed position as explained above by pivoting upper end sections 46a,b downwardly about pivot structures 52a,b, and by pivoting lower end sections 50a,b upwardly about respective lower pivot structures 54a,b. In the collapsed configuration, sections 46a,b and 50a,b are generally aligned with the long axis of bow 78 for compact storage and easy transport and thereby minimize the possibility that blind 10 might catch or snag on underlying foliage.
Additionally, the collapsible feature of blind 10 allows it to be compactly stored without the need for detaching it from bow 78. In the event the archer spots quarry or otherwise wishes to place blind 10 in the extended and ready position, the archer can quickly and readily shift sections 46a,b and 50a,b to their extended positions with one hand while holding bow 78 with the other hand.
As those skilled in the art will appreciate, the present invention contemplates many variations in the preferred embodiment herein described. For example, support members 40, 42 can be configured to present a single pivot point each whereby each member rotates about this pivot point to place the bow-mountable blind in the collapsed position for transport. Additionally, flaps 22 can be configured in a variety of shapes as desired. As a final example, camouflage sheet 16 can be configured of other materials such as burlap, canvas, or nylon as a matter of design choice. | An archery bow-mountable blind is provided which effectively camouflages the movements of the archer, bowstring, and arrow as the bow is being drawn while providing sufficiently clear observation of the target for accurate aiming. The preferred apparatus includes a sheet of camouflage material, a pair of support members for supporting the sheet therebetween, and a pair of attachment straps for coupling the support members to a bow. The camouflage sheet has a plurality of cuts defined therethrough forming a corresponding plurality of flaps and openings. The flaps simulate foliage thereby enhancing the camouflage effect of the apparatus and the openings provide clear observation of the target. The preferred support members are shiftable between extended positions in which the members are generally transverse to the bow's long axis and collapsed positions in which the members are generally aligned with the bow's long axis. | 8 |
BACKGROUND
[0001] 1. Field of the Invention
[0002] The present invention relates to a barrier film and a method for preparing the same.
[0003] 2. Discussion of Related Art
[0004] When electric devices and metal interconnections included in organic or inorganic phosphors, displays, photovoltaic devices, etc. are in contact with external chemical materials such as oxygen or water, they are modified or oxidized, and thus cannot be properly functioning. Accordingly, it is necessary to protect the electric devices from the chemical materials. To this end, a technique of protecting internal electric devices vulnerable to chemical materials using a glass plate as a substrate or a cover plate has been proposed. The glass plate has satisfactory characteristics including light transmittance, a coefficient of thermal expansion, and chemical resistance. However, since glass is heavy, hard, and easily breakable, it should be carefully handled.
[0005] Accordingly, there is an active attempt to replace the glass plate used as a substrate for an electric device with a plastic film or sheet, which is a representative material having a lighter weight, an excellent impact resistance, and higher flexibility, compared with the glass plate. However, it is necessary to complement deficient physical properties of a plastic film commercially produced these days, compared with the glass plate. Particularly, it is most urgently necessary to improve water resistance and gas barrier properties among the physical properties of the plastic film, compared with the characteristics of the glass plate, and a barrier film showing excellence both in gas barrier properties and light transmittance is required.
PRIOR ART DOCUMENT
[0006] 1. Japanese Laid-Open Patent Application No. 2007-090803
SUMMARY OF THE INVENTION
[0007] The present invention is directed to providing a barrier film applied to an organic or inorganic phosphor device, a display device, or a photovoltaic device to effectively block environmental chemical materials such as water or oxygen, protect an electronic device therein, and maintain excellent optical characteristics, and a method of manufacturing the same.
[0008] In one aspect, the present invention provides a barrier film. In one example, the barrier film of the present invention may be applied to an organic or inorganic phosphor device, a display device, or a photovoltaic device. The exemplary barrier film 10, as shown in FIG. 1 , may sequentially include a base layer 14, a first dielectric layer 13, an inorganic layer 12, and a second dielectric layer 11, and satisfy General Formula 1. Here, the inorganic layer may have a refractive index of 1.65 or more. In addition, a thickness of the first dielectric layer may be less than 100 nm, and a thickness of the second dielectric layer may be equal to or larger than that of the first dielectric layer. That is, the thickness of the second dielectric layer may be equal to or larger than that of the first dielectric layer. Meanwhile, the inorganic layer may have a refractive index of at least 1.65 or more, for example, 1.7 or more, 1.75 or more, 1.8 or more, 1.85 or more, 1.9 or more, 1.95 or more, 1.96 or more, 1.97 or more, 1.98 or more, 1.99 or more, or 2.0 or more. The upper limit of the refractive index of the inorganic layer may be, but is not particularly limited to, for example, 3.0 or less, 2.5 or less, 2.4 or less, 2.3 or less, or 2.2 or less. The present invention may provide a barrier film having gas barrier properties and excellent optical characteristics by controlling the thicknesses and refractive indices of the first dielectric layer and the second dielectric layer in addition to the inorganic layer having a relatively high refractive index.
[0000] n 2 ≦n 1 <n i [General Formula 1]
[0009] In General Formula 1, n 1 represents the refractive index of the first dielectric layer, n 2 represents the refractive index of the second dielectric layer, and n i represents the refractive index of the inorganic layer.
[0010] Optical characteristics of the film having a structure in which several layers are laminated are changed by the refractive indices and thicknesses of the components layer. Particularly, since the reflection and refraction of light occur at an interface between two layers having different refractive indices, the laminating materials, which give rise to the difference in refractive index among the laminated layers, and the lamination sequence have profound effects on the optical characteristics of the multilayer film. The first dielectric layer, the inorganic layer, and the second dielectric layer may be formed of materials known to those of ordinary skill in the art without limitation as long as the materials satisfy the relationship of the refractive indices, and as the relationship of the refractive indices and the thickness relationship are satisfied, the barrier film having excellent optical characteristics may be manufactured.
[0011] The term “refractive index” used herein may be, unless particularly defined, a refractive index in the range of a wavelength from 300 to 1000 nm. In one example, the “refractive index” used herein may refer to a refractive index in a wavelength of 550 or 633 nm.
[0012] In addition, the barrier film of the present invention having excellent optical characteristics may be manufactured by satisfying the thickness relationship according to General Formula 4.
[0000] 0.01≦ d 1 /d 2 ≦1 [General Formula 4]
[0013] In General Formula 4, d 1 is the thickness of the first dielectric layer, and d 2 is the thickness of the second dielectric layer.
[0014] As described above, a ratio of the thickness of the first dielectric layer d 1 to the thickness of the second dielectric layer d 2 may be 0.01 to 1, or 0.01 or more and less than 1, for example, 0.02 to 1.0, 0.05 to 1.0, 0.1 to 1.0, 0.1 to 0.9, 0.1 to 0.8, or 0.1 to 0.7. As described above, as the ratio of the thickness between the first dielectric layer and the second dielectric layer is limited to a specific range, a film having excellent gas barrier properties and light transmittance may be manufactured.
[0015] As described above, the thickness of the first dielectric layer d 1 may be less than 100 nm, for example, 5 to 98 nm. In addition, the thickness of the first dielectric layer may be 10 to 95 nm, 10 to 90 nm, 10 to 85 nm, 10 to 80 nm, or 10 to 75 nm. That is, the relationship of the thickness between the first dielectric layer and the second dielectric layer, which satisfies General Formula 4 of the present invention, may be established when, for example, the thickness of the first dielectric layer is less than 100 nm. In addition, in one example, the thickness of the second dielectric layer d 2 may be 10 nm to 1 μm, 10 to 900 nm, 20 to 800 nm, 30 to 700 nm, 35 to 600 nm, 40 to 500 nm, or 45 to 400 nm. As the thickness relationship is satisfied, the first dielectric layer and the second dielectric layer of the present invention may realize excellent gas barrier properties and light transmittance with the following zinc oxide-based inorganic layer having a higher refractive index than a silicon oxide-based inorganic layer.
[0016] In addition, in an exemplary embodiment of the present invention, the refractive index of the first dielectric layer n 1 and the refractive index of the second dielectric layer n 2 may satisfy General Formula 2.
[0000] 0.5≦( n 2 −1)/( n 1 −1)≦1 [General Formula 2]
[0017] As shown in General Formula 2, the ratio (n 2 −1)/(n i −1) of the refractive index of the second dielectric layer n 2 to the refractive index of the first dielectric layer n 1 may be 0.5 to 1, preferably, 0.55 to 1, 0.6 to 1, 0.65 to 1, or 0.7 to 1.
[0018] In addition, in an exemplary embodiment of the present invention, the refractive index of the first dielectric layer n 1 and the refractive index of the inorganic layer n i may satisfy General Formula 3.
[0000] 0.3≦( n 1 −1)/( n i −1)≦0.95 [General Formula 3]
[0019] As shown in General Formula 3, the ratio (n 1 −1)/(n i −1) of the refractive index of the first dielectric layer n 1 to the refractive index of the inorganic layer n i may be 0.3 to 0.95, preferably 0.35 to 0.85, 0.4 to 0.8, 0.4 to 0.75, 0.4 to 0.7, or 0.45 to 0.7.
[0020] According to the present invention, a film having excellent light transmittance may be manufactured by limiting the ratio of the refractive indices between the first dielectric layer and the second dielectric layer and/or the ratio of the refractive indices between the inorganic layer and the second dielectric layer in a specific range.
[0021] In an exemplary embodiment of the present invention, the refractive index of the base layer may be, but is not particularly limited to, 1.45 to 1.75, 1.45 to 1.7, or 1.5 to 1.65. As long as satisfying General Formula 1, the refractive index of the first dielectric layer n 1 or the refractive index of the second dielectric layer n 2 may be, but is not particularly limited to, 1.35 to 1.9, 1.4 to 1.9, 1.45 to 1.9, or 1.45 to 1.8.
[0022] In addition, when the refractive index of the base layer is n s , the refractive index of the base layer may be lower than the refractive index of the inorganic layer n 1 . In one example, the refractive index of the base layer n s and the refractive index of the inorganic layer n i may satisfy General Formula 5.
[0000] n s <n i [General Formula 5]
[0023] In the present invention, the refractive index of the base layer n s and the refractive index of the first dielectric layer n 1 may also satisfy General Formula 6.
[0000] 0.5≦ n s /n 1 ≦1.5 [General Formula 6]
[0024] That is, the material for the base layer of the present invention is not particularly limited, but may satisfy General Formula 5 or 6. For example, the ratio (n s /n 1 ) of the refractive index of the base layer n s to the refractive index of the first dielectric layer n 1 may be 0.5 to 1.5, and specifically, 0.6 to 1.4 or 0.7 to 1.3.
[0025] The relationship between the thickness of the first dielectric layer and that of the second dielectric layer of the barrier film may be suitably controlled according to material characteristics and relationship of the refractive indices of the layers, and characteristics of the inorganic layer of the barrier film, and satisfy General Formula 4. For example, as the thickness relationship is satisfied, excellent gas barrier properties and light transmittance may be realized with a zinc oxide-based inorganic layer that will be described below.
[0026] The barrier film may also have excellent light transmittance in the visible region. In one example, the present invention may exhibit light transmittance of 88% or more in the wavelength range of 380 to 780 nm. In the present invention, the barrier film sequentially including the base layer, the first dielectric layer, the inorganic layer, and the second dielectric layer may maintain excellent transparency. For example, the barrier film formed by satisfying the specific relationship of the refractive indices among the layers or the relationship of the thickness ratio may have light transmittance of 88% or more, 89% or more, or 90% or more in the range of a wavelength from 380 to 780 nm.
[0027] In addition, the barrier film may exhibit a lower yellowness index and excellent light transmittance. In one example, when the specific relationship of the refractive indices among the layers or the relationship of the thickness ratio is satisfied, the barrier film having a lower yellowness index may be provided. For example, the yellowness index according to ASTM E313 may be −2.0 to 2.0, −1.8 to 1.8, −1.5 to 1.9, or −1.3 to 1.8.
[0028] In addition, the barrier film may have a b* value of the CIE coordinate system in a range of −1.0 to 1.5 or −0.5 to 1.3. The CIE coordinate system is a color level defined in the Commission Internationale de l'Eclairage (CIE), and is also referred to as the CIE colorimetric system or the CIE color space. The coordinate system is a uniform color space coordinate, and a coordinate system today standardized in the world because it has very small difference from the color recognition of human eyes. The CIE coordinate system is defined by L* denoting brightness and a* and b* denoting chromaticity, and the a* and b* represent directions of the color. Specifically, when the a* value is a positive number, it represents the red direction, when the a* value is a negative number, it represents the green direction, when the b* value is a positive number, it represents the yellow direction, and when the b* value is a negative number, it represents the blue direction. The b* value of a barrier film may be determined by a known method.
[0029] In an exemplary embodiment of the present invention, the first dielectric layer, the inorganic layer, and the second dielectric layer may use a variety of materials which can be known by those of ordinary skill in the art without limitation as long as the relationship of the refractive indices represented by General Formula 1 and the thickness relationship are satisfied.
[0030] In one example, the base layer may include at least one selected from the group consisting of a polyester-based resin such as polyethyleneterephthalate, polycarbonate, polyethylenenaphthalate, or polyarylate, a polyether-based resin such as polyethersulfone, a polyolefin-based resin such as a cyclo-olefin polymer, a polyethylene resin, or a polypropylene resin, a cellulose-based resin such as diacetylcellullose, triacetylcellullose, or acetylcellullosebutylate, a polyimide-based resin, and an epoxy-based resin. In the present invention, preferably the base layer may include polycarbonate or a cyclo-olefin polymer. In one example, a thickness of the base layer may be, but is not particularly limited to, 2 to 200 μm, preferably, 5 to 190 μm, 10 to 180 μm, 20 to 180 μm, or 20 to 150 μm. In addition, the base layer may include a separate coated layer laminated on an opposite surface of the above-described multilayer laminate. The coated layer may be laminated to a thickness of 0.01 to 10 μm to improve optical characteristics, complement mechanical properties, or give functionality to make a future process easy.
[0031] The material for the inorganic layer is not limited as long as the above-described range of the refractive index is satisfied, and may be formed of, for example, an oxide or nitride of at least one metal selected from the group consisting of Al, Zr, Ti, Hf, Ta, In, Sn, Zn, and Si. The thickness of the inorganic layer may be 5 to 100 nm, 10 to 90 nm, or 10 to 80 nm. In one example, the inorganic layer of the present invention may be formed of a zinc oxide-based material. The zinc oxide-based material may be a zinc oxide-based material not containing any dopant, or a zinc oxide-based material containing dopants. The dopant which can be doped to the zinc oxide may be, but not limited to, at least one element selected from the group consisting of Ga, Si, Ge, Al, Sn, Ge, B, In, Tl, Sc, V, Cr, Mn, Fe, Co, and Ni, or an oxide thereof. The dopant may be doped to zinc oxide (ZnO) in the type of a cation, which substitutes a Zn moiety and increases the concentration of electrons or holes of the zinc oxide-based inorganic layer. However, not to degrade electron mobility, the concentration of the dopant may be 0.1 to 20 wt %. Alternatively, when mechanical properties and optical characteristics are adjusted using a dopant, the concentration of the dopant may be increased at 15 to 85 at %. In an exemplary embodiment of the present invention, the inorganic layer may be formed of, for example, zinc tin oxide as long as it satisfies the refractive index without particular limitation. As the zinc tin oxide is applied as the inorganic layer to the barrier film satisfying the above-described relation of the refractive indices and the thickness relationship, the barrier film may exhibit excellent gas barrier properties and optical characteristics.
[0032] In an exemplary embodiment of the present invention, the first dielectric layer or the second dielectric layer may be an organic or organic-inorganic composite layer. In one example, the first dielectric layer or the second dielectric layer may include at least one selected from the group consisting of an acrylic resin, a urethane-based resin, a melamine resin, an alkyde resin, an epoxy-based resin, a siloxane-based polymer, and an organic silane compound represented by Formula 1.
[0000]
[0033] In Formula 1, X may be hydrogen, a halogen, an alkoxy group, an acyloxy group, an alkylcarbonyl group, an alkoxycarbonyl group, or —N(R 2 ) 2 , in which R 2 is hydrogen or an alkyl group, R 1 is an alkyl group, an alkenyl group, an alkynyl group, an aryl group, an arylalkyl group, an alkylaryl group, an arylalkenyl group, an alkenylaryl group, an arylalkynyl group, an alkynylaryl group, a halogen, an amino group, an amide group, an aldehyde group, an alkylcarbonyl group, a carboxyl group, a mercapto group, a cyano group, a hydroxyl group, an alkoxy group, an alkoxycarbonyl group, a sulfonyl group, a phosphoryl group, an acryloyloxy group, a methacryloyloxy group, or an epoxy group, Q is a single bond, an oxygen atom, or —N(R 2 )—, in which R 2 is a hydrogen atom or an alkyl group, and m is a number of 1 to 3.
[0034] The organic silane may be at least one selected from the group consisting of the compound represented by Formula 1, and when a type of organic silane compound is used, crosslinking can occur.
[0035] An example of the organic silane may be selected from the group consisting of methyltrimethoxysilane, methyltriethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, diphenyldimethoxysilane, diphenyldiethoxysilane, phenyldimethoxysilane, phenyldiethoxysilane, methyldimethoxysilane, methyldiethoxysilane, phenylmethyldimethoxysilane, phenylmethyldiethoxysilane, trimethylmethoxysilane, trimethylethoxysilane, triphenylmethoxysilane, triphenylethoxysilane, phenyldimethylmethoxysilane, phenyldimethylethoxysilane, diphenylmethylmethoxysilane, diphenylmethylethoxysilane, dimethylmethoxysilane, dimethylethoxysilane, diphenylmethoxysilane, diphenylethoxysilane, 3-aminopropyltriethoxysilane, 3-glycidoxypropyltrimethoxysilane, p-aminophenylsilane, allyltrimethoxysilane, n-(2-aminoethyl)-3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-aminopropyltrimethoxysilane, 3-glycidoxypropyldiisopropylethoxysilane, (3-glycidoxypropyl)methyldiethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane, 3-methacryloxypropylmethyldiethoxysilane, 3-methacryloxypropylmethyldimethoxysilane, 3-methacryloxypropyltrimethoxysilane, n-phenylaminopropyltrimethoxysilane, vinylmethyldiethoxysilane, vinyltriethoxysilane, vinyltrimethoxysilane, and a mixture thereof.
[0036] In one example, the first dielectric layer or the second dielectric layer may further include at least one selected from the group consisting of pentaerythritol triacrylate, hydroxyethylacrylate, hydroxypropylacrylate, polyethyleneglycol monoacrylate, ethyleneglycol monoacrylate, hydroxybutylacrylate, glycidoxymethacrylate, propyleneglycol monoacrylate, trimethoxysilylethyl epoxycyclohexane, acrylic acid, and methacrylic acid.
[0037] In one example, the epoxy-based resin may be at least one selected from the group consisting of an alicyclic epoxy resin and an aromatic epoxy resin.
[0038] The alicyclic epoxy resin may be, for example, at least one selected from the group consisting of an alicyclic glycidyl ether-type epoxy resin and an alicyclic glycidyl ester-type epoxy resin. In addition, as an example, Celloxide 2021P (Daicel), that is, 3,4-epoxycyclohexyl-methyl-3,4-epoxycyclohexane carboxylate, and derivatives thereof may be used, which may be stable at a high temperature, colorless and clear, and have excellent toughness, adhesion and adhesive strength for a laminate. Particularly, when the alicyclic epoxy resin is used for coating, excellent surface hardness is exhibited.
[0039] The aromatic epoxy resin may be at least one aromatic epoxy resin selected from the group consisting of a bisphenol A-type epoxy resin, a bromo bisphenol A-type epoxy resin, a bisphenol F-type epoxy resin, a bisphenol AD-type epoxy resin, a fluorene-containing epoxy resin, and a triglycidyl isocyanurate.
[0040] An inorganic material for forming the first dielectric layer or the second dielectric layer may be a coating composition formed by a sol-gel reaction, for example, at least one selected from the group consisting of SiO x (wherein x is an integer of 1 to 4), SiO x N y (wherein x and y are each an integer of 1 to 3), Al 2 O 3 , TiO 2 , ZrO, and ITO.
[0041] In addition, the first dielectric layer or the second dielectric layer may further include at least one selected from the group consisting of a metal alkoxide compound represented by Formula 2.
[0000]
[0042] In Formula 2, M is any one metal selected from the group consisting of aluminum, zirconium and titanium, R 3 is a halogen, an alkyl group, an alkoxy group, an acyloxy group or a hydroxyl group, and z is 3 or 4.
[0043] In an exemplary embodiment of the present invention, the first dielectric layer or the second dielectric layer may further include a filler of nanoparticles to adjust the refractive index. The filler may be, but is not limited to, a metal oxide or a metal nitride. In one example, the filler may include at least one selected from the group consisting of CaO, CaF 2 , MgO, ZrO 2 , TiO 2 , SiO 2 , In 2 O 3 , SnO 2 , CeO 2 , BaO, Ga 2 O 3 , ZnO, Sb 2 O 3 , NiO, and Al 2 O 3 . In addition, when the filler is used in coating for a dielectric layer, a surface of the filler may be treated as needed to improve an adhesive strength. For example, the surface of the filler may be treated with epoxy silane, acryl silane, or vinyl silane. The filler may have a diameter of 0.1 to 150 nm, 0.1 to 100 nm, 1 to 90 nm, 1 to 70 nm, or 1 to 50 nm. As the size of the filler is controlled in the above range, transparency and a desired refractive index of the film of the present invention may be satisfied.
[0044] The first dielectric layer or the second dielectric layer may be cured by thermal curing, photocuring, or a combination thereof, and may further include a thermal acid generator or a photo acid generator as needed.
[0045] When the curing is performed with heat, thermal resistance of the base layer should be considered, and an amorphous base layer may be cured at a glass transition temperature or less, and if having crystallinity, the curing may be used at a higher temperature than the glass transition temperature. For example, a cyclo-olefin copolymer (COP) may be cured at 120° C. or less, polycarbonate (PC) may be cured at 130° C. or less, poly(ethylene terephthalate) (PET) may be cured at 130° C. or less, and polyethylenenaphthalate (PEN) may be cured at 150° C. or less.
[0046] The present invention also relates to a method of manufacturing the above-described barrier film. The exemplary manufacturing method may include sequentially laminating a first dielectric layer, an inorganic layer having a refractive index of 1.65 or more, and a second dielectric layer on a base layer. In addition, the first dielectric layer, the inorganic layer, and the second dielectric layer may satisfy General Formula 1, the thickness of the first dielectric layer may be less than 100 nm, the thickness of the second dielectric layer may be equal to or larger than the thickness of the first dielectric layer.
[0000] n 2 ≦n 1 <n i [General Formula 1]
[0047] In General Formula 1, n 1 is a refractive index of the first dielectric layer, n 2 is a refractive index of the second dielectric layer, and n i is a refractive index of the inorganic layer.
[0048] To sequentially form the first dielectric layer, the inorganic layer, and the second dielectric layer on the base layer, vacuum evaporation, sputtering, atomic layer deposition, ion plating, or coating may be used, but the present invention is not limited thereto, and thus a common method known to the art may be used.
EFFECT
[0049] A barrier film of the present invention can be applied to an organic or inorganic phosphor device, a display device, or a photovoltaic device to effectively block chemical materials such as water or oxygen, protect an electronic device therein, and maintain excellent optical characteristics.
BRIEF DESCRIPTION OF THE DRAWINGS
[0050] FIG. 1 is a diagram showing an exemplary barrier film according to the present invention.
DESCRIPTIONS OF REFERENCE NUMERALS
[0000]
10 : barrier film
11 : second dielectric layer
12 : inorganic layer
13 : first dielectric layer
14 : base layer
DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS
[0056] Hereinafter, the present invention will be described in further detail with reference to examples according to the present invention and comparative examples not according to the present invention. However, the scope of the present invention is not limited to the following examples.
Example 1
[0057] A first dielectric layer having a refractive index of 1.65 was formed to have a thickness of 40 nm on a polycarbonate (PC) film (thickness: 100 μm, refractive index: 1.61) using a coating solution (TYT65, Toyo Ink Co., Ltd.) prepared by including metal oxide nanoparticles (titanium dioxide) in an acryl resin. Specifically, the coated layer was formed by coating the PC film with the coating solution using a meyer bar, drying the coated film at 100° C. for approximately 2 minutes, and irradiating the dried film with UV rays for coating at an intensity of 0.5 J/cm 2 . Zinc tin oxide having a refractive index of 2.0 was deposited on the film coated as described above as an inorganic layer to a thickness of approximately 20 nm by sputtering in a 3 mTorr argon atmosphere. A second dielectric layer having a refractive index of 1.48 was formed on the deposited layer to a thickness of 91 nm using a coating solution prepared of pentaerythritol triacrylate and methylethoxy silane in a weight ratio of 40:60, and thus a barrier film was manufactured. Specifically, a half of the total weight of the pentaerythritol triacrylate used in the coating solution was a reaction product with isocyanato triethoxysilane. The coating solution was prepared by hydrating a mixture of the pentaerythritol triacrylate and methoxysilane using 2 equivalent of water based on silanol and 1.5 parts by weight of 0.1 N hydrochloric acid based on the solid content at room temperature for 30 hours. The second dielectric layer was formed by coating the PC film with the coating solution using a meyer bar, drying the coated film at room temperature for 3 minutes, and drying the resulting product at 100° C. for 1 minute.
Comparative Example 1
[0058] A barrier film was manufactured by the same method as described in Example 1, except that a first dielectric layer was formed to have a thickness of 91 nm, and a second dielectric layer was formed to have a thickness of 40 nm.
Comparative Example 2
[0059] A barrier film was manufactured by the same method as described in Example 1, except that a dielectric layer (thickness: 40 nm) having a refractive index of 1.48 was formed as a first dielectric layer using a coating solution prepared of pentaerythritol triacrylate and methylethoxy silane in a weight ratio of 40:60, and a dielectric layer (thickness: 91 nm) having a refractive index of 1.65 was formed as a second dielectric layer using a coating solution (TYT65, Toyo Ink Co., Ltd.) including metal oxide nanoparticles in an acryl resin.
Example 2
[0060] A barrier film was manufactured by the same method as described in Example 1, except that a first dielectric layer was formed to have a thickness of 20 nm and a second dielectric layer was formed to have a thickness of 100 nm.
Comparative Example 3
[0061] A barrier film was manufactured by the same method as described in Example 2, except that a second dielectric layer was not used.
Example 3
[0062] A barrier film was manufactured by the same method as described in Example 1, except that a PET film (thickness: 50 μm, refractive index: 1.64) was used as a base layer, a first dielectric layer was formed to have a thickness of 40 nm, and a second dielectric layer was formed to have a thickness of 100 nm.
Example 4
[0063] A barrier film was manufactured by the same method as described in Example 1, except that a cyclo-olefin copolymer (COP) film (thickness: 50 μm, refractive index: 1.53) was used as a base layer, a first dielectric layer was formed to have a thickness of 35 nm, and a second dielectric layer was formed to have a thickness of 960 nm.
Comparative Example 4
[0064] A first dielectric layer having a refractive index of 1.48 was formed on a PC film (thickness: 100 μm, refractive index: 1.61) to a thickness of 0.1 μm using a coating solution prepared of pentaerythritol triacrylate and methylethoxy silane in a weight ratio of 40:60. A zinc tin oxide layer having a refractive index of 2.0 was deposited on the coated film as an inorganic layer to a thickness of approximately 20 nm by sputtering in a 3 mTorr argon atmosphere. A second dielectric layer was formed on the deposited layer to a thickness of 0.26 μm using the coating solution, and thus a barrier film was manufactured.
Example 5
[0065] A barrier layer was formed by the same method as described in Example 4, except that a first dielectric layer was formed to have a thickness of 75 nm, and a second dielectric layer was formed to have a thickness of 75 nm.
[0066] 1. Measurement of Refractive Index and Thickness
[0067] Refractive indices and thicknesses of the first dielectric layers, the second dielectric layers, and the inorganic layers according to Examples and Comparative Examples of the present invention were measured by the following methods.
[0068] Samples for measuring a refractive index were prepared by forming a dielectric layer or an inorganic layer on a Si substrate. The refractive index of the sample was obtained by analysis using an ellipsometer (M2000U, J.A. Woolam Co.).
[0069] The thicknesses of layers coated on a base layer were measured using a scanning electron microscope (S4800, Hitachi).
[0070] 2. Measurement of Average Light Transmittance
[0071] Optical transmission spectrums of the barrier films manufactured according to Examples and Comparative Examples were evaluated using Shimadzu UV3600 (average light transmittance from 380 to 780 nm).
[0072] 3. Measurement of Water Vapor Transmission Rate (WVTR)
[0073] WVTRs of the barrier films manufactured according to Examples and Comparative Examples were evaluated using Lyssy L80 at 30° C. and 100% R.H.
[0074] 4. Measurement of Yellowness Index and CIE Value
[0075] Yellowness index (according to ASTM E313) and a* and b* values in the CIE color coordinates of the barrier films manufactured according to Examples and Comparative Examples were obtained from a light transmission spectrum using a utility provided by Shimadzu.
[0000]
TABLE 1
Average light
Yellow-
WVTR
transmittance
ness
(g/m 2
(%)
a*
b*
index
day)
Example 1
90.7
−0.7
0.2
0.0
<0.03
Example 2
90.8
−1.0
1.3
1.8
<0.03
Example 3
91.7
−0.9
1.2
1.6
<0.03
Example 4
91.1
−0.7
−0.4
−1.3
<0.03
Example 5
90.2
−0.7
−0.4
−1.3
<0.03
Comparative
85.7
−0.1
1.3
2.5
<0.03
Example 1
Comparative
87.5
−0.2
−1.2
−2.5
<0.03
Example 2
Comparative
84.5
−0.1
2.9
5.6
<0.03
Example 3
Comparative
86.6
−0.6
−2.5
−5.5
<0.03
Example 4 | Provided are a barrier film and a method for preparing the same. Particularly, the barrier film is applied to an organic or inorganic phosphor, a display, or a photovoltaic device to effective block chemical materials such as water or oxygen, protect an electronic device therein, and maintain excellent optical characteristics. | 2 |
FIELD OF THE INVENTION
The present invention relates to a method for removing defects from a traveling yarn being wound onto a bobbin at a winding head of a bobbin winding machine. More particularly, the invention relates to such a method wherein the length of the yarn wound onto the bobbin is determined and, when a yarn defect is detected, the winding process is interrupted by cutting the traveling yarn, the winding bobbin is stopped, a driving roller rotates the bobbin in an unwinding direction for a predetermined number of revolutions sufficient to unwind the defect and in the process the yarn unwound from the bobbin is aspirated into a suction tube positioned in front of the bobbin, the unwound yarn and the other cut end of the yarn are subsequently inserted into a yarn end connecting device wherein the unwound yarn from the winding bobbin is cut to remove the defective portion, and the winding process is restarted after the yarn ends have been connected.
BACKGROUND OF THE INVENTION
In the course of rewinding a yarn from a delivery bobbin to a winding bobbin in a bobbin winding machine, the traveling yarn is continuously monitored for yarn defects. The yarn defects are cut out of the yarn, the two yarn ends being created are connected with each other again, and the winding process is started again. In the course of thusly removing yarn defects, it must be assured that the yarn defect is completely removed, regardless of whether it involves punctiform or long thin or thick sections. Furthermore, only the defective yarn portion is to be removed during the process, so that the least amount of yarn waste is created.
A winding device is known from German Published, Non-Examined Patent Application DE-OS 20 36 898, wherein the winding bobbin is immediately braked after a yarn defect has been detected, without the yarn being cut. The rotational pulses of the bobbin or the winding drum are counted from the appearance of the yarn defect until the winding bobbin comes to a stop. As the winding bobbin is subsequently unwound, the rotational pulses are counted backward to zero when the defective yarn is unwound. The unwound yarn is aspirated as a loop and then contains the defect. After cutting off the defective yarn loop, the resulting defect-free upper thread and lower thread are connected with each other.
This known method is only sensible at low winding speeds, because otherwise a considerable length of yarn would be wound onto the winding bobbin from the appearance of the defect until the stopping of the winding bobbin, which then constitutes waste. Furthermore, when braking sharply there is the danger of the yarn tearing. If the surface of the bobbin is braked by means of a winding roller, there is the danger of damage to the outermost yarn layers. The time required for unwinding the excess yarn furthermore results in a reduction in the efficiency of the machine.
It is also known from German Patent Publication DE 39 11 505 A1 to permit the traveling yarn to run up on the sharply braked winding bobbin following the appearance of a defect. This method also results in a considerable amount of waste yarn being wound onto the winding bobbin in the braking phase. The time required for the reverse winding of the winding bobbin during unwinding of the defective yarn is either limited by a time relay, wherein the predetermined unwinding time is based on experimental values or, in the course of unwinding, the yarn is directed past a sensor for detecting the passage of the defective portion. The steps for eliminating the defective portion and for restoring the yarn connection are initiated thereafter.
If the time for unwinding the defective yarn portion is limited by a time relay, the unwinding time must be set to the most disadvantageous circumstances which could result when the yarn end wound on the winding bobbin is not immediately aspirated and the defect is an extended one. For this reason, the suction tube is left to aspirate along the circumference of the delivery bobbin rotating in the unwinding direction until it can be assumed on the basis of experimental values that the yarn end has been aspirated. As a result, completely uncontrollable yarn lengths are aspirated into the suction tube, depending on whether the yarn start was already found immediately upon positioning the suction tube in front of the delivery bobbin, or the starting end of the yarn was detected only at the end of the predetermined search time.
A method for cleaning out yarn defects is known from European Patent Publication EP 0 419 821 B1, wherein a differentiation is made between conventional yarn defects and yarn defects caused by an auxiliary piecing yarn which is used to repair yarn breaks in ring spinning machines. If a yarn defect caused by the normal spinning process occurs, a short, predetermined yarn piece is pulled off the winding bobbin and removed, while when a defect caused by piecing occurs, which can be detected by means of the yarn cross section, sufficient yarn is always removed from the winding bobbin so that the auxiliary yarn in its entire known length, together with the pieced location, is removed. Therefore two different yarn lengths are predetermined for the removal of any given defect, the shorter predetermined yarn length being intended for defects caused by the spinning process, and the longer predetermined yarn length being intended for defects caused by the auxiliary yarn. Because of the fixed yarn lengths to be removed, this method does not permit the precision removal of short yarn defects caused by spinning because then it would not be assured that longer yarn defects would be completely removed because of the fixed cleaning out length.
OBJECT AND SUMMARY OF THE INVENTION
It is accordingly an object of the instant invention to provide an improved method for removing yarn defects detected during a yarn winding operation and in the process to reduce yarn waste.
This object is attained in accordance with the invention by providing a method for removing defects from a traveling yarn being wound from a delivery bobbin onto a winding bobbin at a winding head of a bobbin winding machine, basically comprising the steps of monitoring the traveling yarn for defects and, when a yarn defect has been detected, interrupting the winding process by cutting the yarn downstream of the detected defect thereby forming an upper yarn with the defect extending to the winding bobbin and a lower yarn extending from the delivery bobbin. The winding bobbin is stopped and the length of the upper yarn wound onto the winding bobbin between the time of the detection of the defect and the time of making the yarn cut is determined. The winding bobbin is then rotated in an unwinding direction for a predeterminable number of revolutions to unwind therefrom the defect of the upper yarn, and the upper yarn unwound from the winding bobbin is aspirated into a suction tube thereat. The presence of the upper yarn within the suction tube is sensed, and the unwinding of the upper yarn is stopped when the determined yarn length has been aspirated into the suction tube. The aspirated upper yarn from the winding bobbin is inserted into a yarn end connecting device with the yarn defect disposed outside of the yarn end connecting device to be cut and discarded, and similarly the lower yarn from the delivery bobbin is inserted into the yarn end connecting device. The upper and lower yarns are then spliced while cutting and removing the defect of the upper yarn, and then the winding process is restarted with no defect remaining in the yarn.
In accordance with the method of the invention, it is thus possible to completely remove the yarn over its defective length, but still to limit the removed yarn length to essentially only the length of the defect. So that only the yarn defect is exclusively cleaned, the entry of the yarn into the suction tube, which aspirates the defective yarn from the winding bobbin while rotating in the unwinding direction, is monitored by a sensor arranged in the suction tube. As soon as the sensor detects the entry of the yarn into the suction tube, the length of yarn unwound from the winding bobbin and entering the suction tube is determined. This yarn unwinding step and the aspiration of the yarn is stopped when a sufficient length of unwound yarn has been aspirated into the suction tube, as determined on the basis of the yarn winding length determined after detection of the defect, so that the length of yarn wound up since the appearance of the yarn defect will remain outside of the yarn end connecting device to be cut off when subsequently inserted into the yarn end connecting device. As a result, a completely defect-free upper yarn is provided for connection with the lower yarn.
The invention also makes it possible to remove relatively long yarn defects without generating additional waste. In this case, the cutting signal of the cleaner which checks the yarn quality to determine defects is suppressed until a yarn corresponding to the desired physical requirements of the yarn is again registered.
Since, besides those yarn defects limited in their length, there are also yarn defects whose length cannot be predicted, for example because of the presence of a wrong yarn count or with yarn with a continuing defect, a limitation on the length of the yarn to be checked is preselected for long yarn defects. If at the end of this preselected length a defect is still detected to be present in the yarn, the yarn is cut.
If a yarn cut is performed because of such a preselected defect length limitation, it is possible in accordance with a further aspect of the invention to set an alarm signal at the winding head to indicate that a defect has occurred which cannot be corrected by means of a yarn cut and the aspiration and removal of a defined yarn length. Appropriate action is then taken, e.g., further operation of the winding head is blocked, until an operator has checked the winding head and removed the defect.
In a further feature of the invention, it is possible to provide for a change of the delivery bobbin, in addition to removing the yarn defect, when a yarn cut is made because of a preselected length limitation. Under such circumstances, it can be assumed that the yarn remaining on the first delivery bobbin is also defective and that therefore the entire delivery bobbin should be changed.
According to a further aspect of the invention, it is possible to mark or otherwise identify delivery bobbins detected to have defective yarn thereby to prevent them from being again placed into a machine, and possibly also to indicate the reason for the removal of the delivery bobbin. For example, each delivery bobbin or the support for each delivery bobbin, e.g., a pallet, peg tray, or the like, may be provided with a device in which data can be stored to provide information regarding the delivery bobbin at a reading station.
In accordance with another feature of the invention, the length of the already aspirated yarn is compared with the defective length during the removal of yarn defects when the defective yarn end aspirated from the winding bobbin is registered by the sensor in the suction tube. By means of this comparison, a decision can be made whether the defect is already in the suction tube or whether it is necessary to unwind an appropriately longer defective portion of the yarn which has been wound on the winding bobbin. The control of the drive motor of the device which drives the winding bobbin in the unwinding direction, i.e., normally the winding roller, is dependent on this comparison. The suction tube only remains in front of the winding bobbin until the defective piece of yarn has been completely wound off the winding bobbin, and thereafter it is immediately pivoted into a position for inserting the yarn in the yarn end connecting device. Since this step in the present process continues for only the time necessary for the yarn end to be actually registered and the yarn defect to be aspirated off the delivery bobbin, the course of the present process is considerably accelerated in comparison with the conventional method in which the suction tube remains in front of the delivery bobbin for a fixed predetermined length of time.
According to a further feature of the invention, the sensor is positioned in the suction tube at a sufficient distance from its mouth that, with short yarn defects up to a length of a few centimeters, the defective portion of the yarn is already aspirated sufficiently far into the suction tube when the yarn end is first detected in the suction tube by the sensor. In addition, the placement of the sensor in the suction tube can be selected in relation to the distance possibly existing between the cleaner and the cutting device. In order to be able to insert a yarn grasped by means of a suction tube securely into the yarn end connecting device, the yarn must be present in the suction tube to a defined length so that the yarn is in a tensioned state. Since a defective length of only a few centimeters is already contained in the length of yarn which is wound off the winding bobbin during a single revolution of the winding roller, the defective piece of yarn as a rule will already be positioned in the suction tube when the minimum length of yarn required for secure insertion of the yarn into the yarn end connecting device has been aspirated. Therefore, when the sensor registers the yarn end in the suction tube, the latter can be immediately pivoted into a position for inserting the yarn into the yarn end connecting device. Thus, with short yarn defects, it is not necessary that the suction tube remain in front of the delivery bobbin any longer than the time until the yarn end has been registered in the suction tube by the sensor.
Another aspect of the invention makes it possible, at the time when the defective yarn length has been wound off the winding bobbin and has been aspirated by the suction tube, to clamp the yarn in the suction tube. Otherwise, if the pivoting movement of the suction tube for inserting the yarn into the yarn end connecting device is not exactly matched to the revolutions of the winding bobbin while the yarn is unwound, the position of the yarn inside the suction tube can change as a result of the yarn being pulled out or further aspirated, whereby it cannot be assured whether the defective yarn portion lies completely outside of the yarn end connecting device. By means of the yarn clamping provided within the suction tube by the present invention, it is assured that the yarn end aspirated into the suction tube does actually remain in the suction tube and is not pulled out again. For this reason, the clamping of the yarn is only released when the defective yarn is cut at the yarn end connecting device.
Under a further feature of the present invention, the circumferential velocity of the winding roller when the yarn is pulled off the winding bobbin is matched to the pivot movement of the suction tube to accomplish unwinding of a yarn length which precisely corresponds to the yarn length between the winding bobbin and the yarn end connecting device. This aspect of the invention can additionally be used in conjunction with clamping of the yarn in the suction tube, but has particular advantage if the suction tube does not have a clamping device. By means of this step, it is assured that no additional yarn can be aspirated into the suction tube or pulled out of the suction tube during the insertion of the yarn into the yarn end connecting device, and it is therefore assured that the defective yarn portion lies completely outside of the yarn end connecting device after having been inserted therein.
Additional features and advantages of the present invention will be described and understood in more detail with reference to the accompanying drawings and the following description of an exemplary embodiment.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an end elevational view of a winding head on a bobbin winding machine equipped in accordance with the present invention with a suction tube positionable in front of the winding bobbin for aspiration of a yarn following the cutting thereof because of a detected defect, and
FIG. 2 is a similar end elevational view of the winding head of FIG. 1 showing the winding head after the yarn has been inserted into the yarn end connecting device by the suction tube.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to the accompanying drawings and initially to FIG. 1, the structure of a winding head 1 of a bobbin winding machine (not shown in greater detail herein for sake of simplicity and clarity of illustration) is schematically shown. Only the features of the winding head necessary for understanding the invention are represented and described.
FIG. 1 represents the situation in which, because a yarn defect has been detected, the normal operation of the winding head 1 for rewinding yarn supplied from a delivery bobbin 3 onto a winding bobbin 4 has been interrupted by lifting the winding bobbin 4 out of peripheral driven contact with a friction driving roller 14, at the same time the yarn path has been interrupted by cutting the yarn, and measures have been initiated for removing the yarn defect, all according to the present invention. This interruption in the normal travel path 2 followed by the yarn during winding operation between the delivery bobbin 3 and the winding bobbin 4 is indicated by the dashed line 2. Following the cutting of the yarn (by conventional means not shown), a yarn gripping suction tube 5 has been pivoted downwardly into a position in the yarn path 2 above the delivery bobbin 3 and has already aspirated the leading end of the yarn 6 fed from the delivery bobbin 3 (referred to herein as the lower yarn) and has delivered such yarn 6 to a yarn end connecting device 8, e.g., a splicing device. To this end, the gripper tube 5 has been pivoted from an initial yarn grasping position, represented at 5' in faint lines, wherein an aspirating opening 7 at the free end of the tube 5 for catching the lower yarn 6 is in the position 7' in the yarn path 2, into the position represented at 5 in full lines by means of a drive (not represented here) which is connected by means of a line 5a with a main central control device 9 for the winding head 1. The pivot joint 10, around which the gripper tube 5 is pivoted, simultaneously provides a pneumatic connection to a vacuum line 11 which communicates with a suction conduit 12 of the central vacuum supply of the bobbin winding machine. The lower yarn 6 held by the gripper tube 5 extends below the yarn end connecting device 8 in an opened yarn tensioner 13, which is also connected with the control device 9 of the winding head 1 via a line 13a.
The cutting of the yarn upon detection of the defect takes place at a location following the defect (as viewed in the direction of yarn travel) and thus, after the cutting of the yarn, the defective portion of the yarn is wound onto the winding bobbin 4. Before removing the defective portion of the yarn, it is therefore necessary to unwind the defective yarn piece completely from the winding bobbin 4, sufficiently that the defective portion of yarn lies completely outside the yarn end connecting device 8 after the yarn has been inserted into the yarn end connecting device 8. At the stage of the process shown in FIG. 1, the winding bobbin 4 has already been lowered again into contact with the winding roller 14. The winding bobbin 4 is supported by a bobbin holder 15, which is seated in a pivot joint 16 in the machine frame 17 (shown only schematically). The actuation of the drive (not represented here) for pivoting the bobbin frame 15 is controlled by the control device 9 via the line 15a.
The winding roller 14 is driven by a drive (not represented here) which is also connected by means of the line 14a with the control device 9. For unwinding the defective yarn piece, the winding roller 14 is driven opposite the normal yarn winding direction, as indicated by the arrow 19, and in turn its circumferential periphery 20 drives the winding bobbin 4 by frictional contact therewith in the yarn unwinding direction 21.
A suction tube 22 is seated in a pivot joint 24 in the machine frame 17, which also provides communication of the tube 22 with the central suction conduit 12 of the vacuum supply of the bobbin winding machine via a line 25 therebetween. In FIG. 1, the suction tube 22 is shown to have been pivoted into an operating position with its mouth 23 in front of the circumferential surface 20 of the winding bobbin 4. FIG. 2 depicts the normal resting position of the suction tube 22. The pivotal movement of the suction tube 22 out of the resting position of FIG. 2 into the operating position of FIG. 1 is performed by means of a drive (not shown) which is connected via a line 22a with the control device 9. A valve (also not represented) is also controlled by the control device 9 and connects the suction tube 22 with the suction conduit 12.
As the winding bobbin 4 is rotated in the unwinding direction, the trailing cut yarn end 27 resting on the circumferential surface 20 of the winding bobbin 4 is aspirated into the suction tube 22 by means of the suction flow, symbolized by the arrow 26 in FIG. 1, prevailing at the mouth 23 of the suction tube 22, represented in section in FIG. 1. The exemplary illustration of FIG. 1 shows the moment in which the yarn end 27 has just reached a sensor 28 disposed in the suction tube 22. The presence of the yarn end 27 in the suction tube 22 is reported by the sensor 28 via the line 28a to the control device 9. The sensor 28 is arranged at a selected distance from the mouth 23 of the suction tube 22 that a sufficient length of yarn is aspirated in order to maintain the yarn tensioned during its insertion into the yarn end connecting device 8. With short defects in the range of millimeters to a few centimeters, the defective yarn piece will have thereby already been unwound and aspirated when the yarn end 27 has been aspirated as far as the sensor 28.
When the yarn end 27 has reached the sensor 28, a check must be made as to whether at this time the defective yarn piece has already been unwound from the winding bobbin 4 and whether therefore the unwinding and aspiration of the yarn can be stopped. To assist in this determination, a yarn cleaner device 29 is positioned within the normal yarn travel path 2 to detect the presence and length of defects in the traveling yarn and the cleaner 29 is connected to the central control device 9 via a signal line 29a to report such data. If the cleaner 29 has reported a short defect to the control device 9, and the length of yarn which has been unwound from the winding bobbin 4 as of the detection of the yarn end 27 by the sensor 28 is longer than the measured defect length, unwinding of the yarn is immediately stopped. The yarn end 27 can be clamped in the suction tube 22 by means of a clamping device 30 before the suction tube 22 is pivoted back into the initial position represented in FIG. 2 and thus, in the process of such pivotal movement of the tube 22, the tube inserts the yarn into the yarn end connecting device 8. The clamping device 30 is controlled via the line 30a by the control device 9. The clamping device 30 is reopened when the end length 27 of the yarn containing the defective yarn piece is subsequently cut from the trailing length of the yarn within the yarn end connecting device, whereby the yarn end 27 with the defect is aspirated through the tube 22 for disposal.
In the instant exemplary embodiment of the invention, the length of the defect in the wound yarn is determined as follows. A magnet wheel 32 is arranged on the shaft 31 of the winding roller 14, having a defined number of magnetic poles uniformly distributed over its circumference, and a sensor 33 is mounted in a stationary disposition on the machine frame adjacent the wheel 32 to register a magnetic pulse upon each passage of each magnetic pole. The number of the pulses of the magnetic poles is counted during each revolution of the magnetic wheel 32 and is transmitted by means of a signal line 33a to the computer of the control device 9, whereby the length of the yarn applied by the winding roller 14 to the winding bobbin 4 is calculated by means of the counted pulses. Of course, those persons skilled in the art will readily recognize that any other method for the measurement of the length of the yarn wound on the winding roller is also possible.
Thus, every time the cleaner 29 recognizes the start of a yarn defect, the length of the defective yarn piece is measured up to the time the cleaner 29 recognizes the end of the defect or until it can be concluded, because the detected measured length of defective yarn is extended, that most or all of the subsequent yarn can also be considered to be defective. At that time, a cutting and clamping device 34 is actuated by the control device 9 via the line 34a for cutting the yarn and the winding bobbin is stopped. The spatial arrangement of the cleaner 29 and the cutting device 34 is taken into consideration when issuing this cutting signal, so that the cut is always made behind the end of the yarn defect (as viewed in the traveling direction of the yarn being wound) with the exception of the yarn cut made when the yarn is continuously defective.
As the winding bobbin 4 is stopped, the cut yarn end 27 is wound onto the surface of the bobbin 4 at which the yarn end comes under the influence of the suction force applied through the suction tube 22, causing the yarn end to be aspirated into the tube as the winding bobbin is driven in reverse in an unwinding direction. When the yarn end 27 reaches the sensor 28 in the suction tube 22, a defined yarn length has necessarily already been unwound from the winding bobbin 4. If the measured length of the defect as previously determined by the cleaner 29 is less than the already unwound yarn length, unwinding of the yarn is immediately stopped and the suction tube 22 is pivoted back into its initial position as represented in FIG. 2 for inserting the yarn into the yarn end connecting device 8. If, however, the measured length of the yarn defect is greater than the yarn length which has been unwound as of the time that the sensor 28 detects the end 27, unwinding of the yarn from the winding bobbin 4 is continued and the additional yarn length continues to be aspirated by the suction tube 22. In the process, the unwound yarn length is continuously measured by means of the length measuring device, namely the sensor 33 in connection with the magnetic wheel 32, and is compared with the defective yarn length originally determined by the cleaner 29. When the yarn length unwound from the winding bobbin 4 matches the previously determined length of the defective yarn, unwinding of the yarn from the winding bobbin and aspiration by the tube 22 are stopped, and the suction tube 22 is then pivoted back into its initial position in order to insert the defective yarn into the yarn end connecting device 8 such that the defective portion of yarn comes to rest outside of the yarn end connecting device 8 and can be aspirated after cutting thereby prior to yarn end connecting operation.
FIG. 2 represents the situation wherein the suction tube 22 has returned to its initial position and in the process has inserted into the yarn end connecting device 8 the non-defective yarn 35, coming from the winding bobbin 4 and trailing the defective portion 36 of yarn. The aspirated defective yarn portion 36 has been drawn into the pivot tube 22 shown in section, and extends as far as the mouth 23 of the suction tube. Since in the instant example of FIG. 2 the defective portion of the yarn is relatively long, exceeding the minimum yarn length necessary to be aspirated as far as the sensor 28, the yarn extends through the opening in the pivot joint 24 into the adjoining vacuum line 11 and the suction conduit 12. To prepare for the connection of the respective upper and lower yarn ends from the winding and delivery bobbins 3,4 (in the instant example by pneumatic splicing in the yarn end connection device 8), the yarn pieces projecting past the splicing device 8 are cut off. Thus, the defective yarn piece 36 is aspirated into the suction conduit 12 by means of the suction flow still prevailing in the suction tube 22. The yarn piece 37 of the lower yarn 6 extending out of the yarn end connecting device 8 into the gripper tube 5 is also severed and aspirated off by the suction flow prevailing in the gripper tube 5. Thereafter splicing of the yarn ends of the upper yarn 35 and the lower yarn 6 is actuated via the line 8a. Following splicing, the yarn is released back into the yarn path 2 shown in dashed lines, and the winding process is again started with a spliced yarn free of defects.
It will therefore be readily understood by those persons skilled in the art that the present invention is susceptible of broad utility and application. Many embodiments and adaptations of the present invention other than those herein described, as well as many variations, modifications and equivalent arrangements will be apparent from or reasonably suggested by the present invention and the foregoing description thereof, without departing from the substance or scope of the present invention. Accordingly, while the present invention has been described herein in detail in relation to its preferred embodiment, it is to be understood that this disclosure is only illustrative and exemplary of the present invention and is made merely for purposes of providing a full and enabling disclosure of the invention. The foregoing disclosure is not intended or to be construed to limit the present invention or otherwise to exclude any such other embodiments, adaptations, variations, modifications and equivalent arrangements, the present invention being limited only by the claims appended hereto and the equivalents thereof. | A method for removing both long and short yarn defects at the winding heads of a bobbin winding machine. Following the appearance of a yarn defect, the length of the defective yarn between the time of the appearance of the defect and the time of a subsequent yarn cut is determined. A suction tube is positioned in front of the winding bobbin to aspirate the defective yarn therefrom. The yarn is unwound, the entry of the yarn into the suction tube is determined by means of a sensor disposed therein, and the yarn length unwound from the winding bobbin and entering the suction tube is determined. The unwinding process is stopped at the time when, on the basis of the detected length of defective yarn, a sufficient yarn length has been aspirated into the suction tube so that, upon subsequent insertion of the yarn from the winding bobbin into the yarn end connecting device, the yarn length wound since the appearance of the yarn defect remains outside of the yarn end connecting device for the purpose of being cut and discarded. | 1 |
CROSS-REFERENCE TO RELATED PATENT APPLICATION
[0001] This application claims the benefit of Korean Patent Application No. 10-2006-0092453, filed on Sep. 22, 2006 in the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference.
BACKGROUND
[0002] 1. Field of the Invention
[0003] The present invention relates to a heat sink and a memory module using the heat sink, and more particularly, to a heat sink that can be applied to a semiconductor package, and a memory module using the heat sink.
[0004] 2. Description of the Related Art
[0005] In general, the driving speed of a semiconductor package, for example, a ball array semiconductor package, is high resulting in a substantial amount of heat radiation. To maintain performance this heat generated in the semiconductor package must be dissipated. Also in general, a memory module in which a plurality of semiconductor packages (semiconductor chips) are mounted on a printed circuit board (PCB) is used to increase memory capacity. Thus, since the packages of the memory module generate a lot of heat, a heat sink is generally used to dissipate heat to the outside.
[0006] The heat sink includes a first heat spreader formed as a thin layer on an upper surface of the PCB on which the plurality of semiconductor packages are mounted, and a second heat spreader formed on a rear surface of the PCB on which the plurality of semiconductor packages are mounted. The first and second heat spreaders face and contact the plurality of semiconductor packages mounted on the PCB to transfer the generated heat to the outside.
[0007] However, in a conventional heat sink, when the first heat spreader formed on the surface of the PCB and the second heat spreader formed on the rear surface of the PCB are coupled, a misalignment is commonly generated between the first heat spreader and the second heat spreader making automation very difficult.
[0008] In addition, the first and second heat spreaders are pressed against each other in the conventional heat sink when pressure is applied from the outside. Thus the first or second heat spreader contacts a circuit element formed on the PCB, for example, a capacitor, thereby generating a short circuit.
SUMMARY
[0009] Embodiments of the present invention provide a heat sink that enables an automation process for coupling heat spreaders by preventing misalignment between heat spreaders. In addition, these embodiments prevent contact between the heat spreaders and a circuit element formed on a printed circuit board (PCB) can be prevented when pressure is applied from the outside.
[0010] Additional embodiments of the present invention provide a memory module using the heat sink described above.
[0011] According to an embodiment of the present invention, a heat sink includes a first heat spreader, a second heat spreader, a first guide pin, a second guide pin, and a coupling unit. The first heat spreader faces and contacts a first component disposed on a first surface of an object to be cooled and directs heat away from the first component. The second heat spreader is disposed on a second surface of the object to be cooled. The second heat spreader faces and contacts a second component to direct heat away from the second component.
[0012] The first guide pin is disposed in a first extension portion near both edges of the first heat spreader, inserted and fixed in an insertion hole corresponding to the first extension portion, and installed in the object to be cooled. The second guide pin faces the first guide pin and is disposed in a second extension portion near both edges of the second heat spreader. The second guide pin is inserted and fixed in the insertion hole corresponding to the second extension portion and is installed in the object to be cooled. The coupling unit closely adheres and couples the first and second heat spreaders to the object to be cooled.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] The above and other features and advantages of the present invention will become more apparent by describing in detail exemplary embodiments thereof with reference to the attached drawings in which.
[0014] FIG. 1 is a dissected perspective view illustrating a heat sink according to an embodiment of the present invention;
[0015] FIG. 2 is a cross-sectional view illustrating the heat sink illustrated in FIG. 1 , according to an embodiment of the present invention;
[0016] FIG. 3 is a dissected perspective view illustrating a heat sink according to another embodiment of the present invention;
[0017] FIG. 4 is a cross-sectional view of the heat sink illustrated in FIG. 3 , according to an embodiment of the present invention;
[0018] FIG. 5 is a dissected perspective view illustrating a heat sink according to another embodiment of the present invention;
[0019] FIG. 6 is a cross-sectional view of the heat sink illustrated in FIG. 5 , according to an embodiment of the present invention;
[0020] FIG. 7 is a dissected perspective view illustrating a heat sink according to another embodiment of the present invention;
[0021] FIG. 8 is a cross-sectional view of the heat sink illustrated in FIG. 7 , according to an embodiment of the present invention;
[0022] FIG. 9 is a dissected perspective view illustrating a heat sink according to another embodiment of the present invention;
[0023] FIG. 10 is a cross-sectional view of the heat sink illustrated in FIG. 9 , according to an embodiment of the present invention;
[0024] FIG. 11 is a plan view of a memory module employing a heat sink, according to an embodiment in the present invention;
[0025] FIGS. 12 and 13 are respectively a cross-sectional view and a perspective view of a memory module employing a heat sink, according to another embodiment of the present invention; and
[0026] FIGS. 14 and 15 are schematic views illustrating a method of combining guide pins to a heat spreader, according to an embodiment of the present invention.
DETAILED DESCRIPTION
[0027] The present invention will now be described more fully with reference to the accompanying drawings, in which embodiments of the invention are shown. The invention may, however, be embodied in many different forms and should not be construed as being limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the concept of the invention to those skilled in the art.
[0028] Heat sink
Embodiment 1
[0029] FIG. 1 is a dissected perspective view illustrating a heat sink according to an embodiment of the present invention. FIG. 2 is a cross-sectional view of the heat sink illustrated in FIG. 1 , according to an embodiment of the present invention.
[0030] Referring to FIGS. 1 and 2 , the heat sink includes a first heat spreader 100 , a second heat spreader 300 , a third heat spreader 500 disposed on the first heat spreader 100 , a first guide pin 106 and a second guide pin 306 respectively installed on the first and second heat spreaders 100 and 300 and inserted into an object 200 to be cooled, and a coupling unit 502 closely adhering and coupling the first and second heat spreaders 100 and 300 to the object 200 to be cooled.
[0031] The first heat spreader 100 is a thin layer facing and contacting a first component 202 disposed on an upper surface of the object 200 to be cooled and directs away heat generated in the first component 202 . The second heat spreader 300 is a thin layer facing and contacting a second component 204 disposed on a rear surface of the object 200 to be cooled and directs away heat generated in the second component 204 . The third heat spreader 500 is a thin layer disposed above-centered to the object 200 to be cooled, facing and contacting a third component 206 and directs away heat generated in the third component 206 .
[0032] The first and second components 202 and 204 generate heat at a lower temperature than the third component 206 . Since the first and second heat spreaders 100 and 300 may have a lower heat generation efficiency than the third heat spreader 500 , the first and second heat spreaders 100 and 300 are formed of a material having a first heat transfer coefficient of about 238 W/mK, for example, aluminum. The third heat spreader 500 is formed of a material having a second heat transfer coefficient of about 397 W/mK, for example, copper.
[0033] In other words, the second heat transfer coefficient of the third heat spreader 500 is greater than the first heat transfer coefficient of the first and second heat spreaders 100 and 300 . In order to increase the surface area of heat dissipation, a plurality of grooves 508 are formed on the upper surface of the third heat spreader 500 .
[0034] The first and third heat spreaders 100 and 500 are coupled by a coupling unit 502 through a compression process or a welding method. In addition, in order for the intense heat in the first through third components 202 , 204 , and 206 to be rapidly transferred to the first through third heat spreaders 100 , 300 , and 500 respectively, thermal interface layers 108 , 308 , and 504 may be respectively interposed between the first component 202 and the first heat spreader 100 , the second component 204 and the second heat spreader 300 , and the first heat spreader 100 and the third heat spreader 500 . For example, the first through third thermal interface layers 108 , 308 , and 504 may be formed of a thermally conductive material such as copper.
[0035] The first guide pin 106 that is inserted and fixed in an insertion hole 208 of the object 200 to be cooled is installed in the first heat spreader 100 . The first guide pin 106 is installed in a first extension portion 104 extending from an inner portion 102 of the first heat spreader 100 near edges of both ends of the first heat spreader 100 . The second guide pin 306 is installed in the second heat spreader 300 and inserted and fixed in the insertion hole 208 of the object 200 to be cooled. The insertion hole 208 of the object 200 to be cooled may pass through the object 200 to be cooled or not. The second guide pin 306 is installed in a second extension portion 304 extending from an inner portion 302 near edges of both ends of the second heat spreader 300 . The cross-section of the first and second guide pins 106 and 306 may be as a cylinder, a V-shape, or a hexahedron depending on the manufacturing method of the first and second guide pins 106 and 306 .
[0036] The first and second extension portions 104 and 304 do not face and contact the first and second components 202 and 204 of the object 200 to be cooled, and are disposed in a corresponding position with the insertion hole 208 of the object 200 to be cooled. The first and second guide pins 106 and 306 may be pen pins that are respectively formed for the first heat spreader 100 and the second heat spreader 300 through a compression process. The compression process for manufacturing the first and second guide pins 106 and 306 will be described later in more detail.
[0037] The first guide pin 106 and the second guide pin 306 are inserted and fixed in the insertion hole 208 of the object 200 to be cooled. When the first and second guide pins 106 and 306 are inserted and fixed in the insertion hole 208 of the object 200 to be cooled, the first and second heat spreaders 100 and 300 are effectively prevented from contacting the object 200 to be cooled when the first and second heat spreaders 100 and 300 are pressed by pressure applied from the outside.
[0038] In particular, the first guide pin 106 and the second guide pin 306 may be separated a predetermined distance apart from each other in the insertion hole 208 of the object 200 to be cooled and be forcibly inserted. In other words, the first and second guide pins 106 and 306 may both be partially inserted into the insertion hole 208 of the object 200 to be cooled and be forcibly inserted. Thus, when the first and second heat spreaders 100 and 300 are pressed by external pressure, the first and second heat spreaders 100 and 300 can be prevented from contacting the object 200 to be cooled more efficiently.
[0039] The first and second guide pins 106 and 306 guide the first and second heat spreaders 100 and 300 when the first and second heat spreaders 100 and 300 are fixed and coupled to the object 200 to be cooled. Thus, the second heat spreader 300 having the second guide pin 306 corresponding to the insertion hole 208 is formed. Then, the object 200 to be cooled is mounted on the second heat spreader 300 such that the insertion hole 208 of the object 200 to be cooled is inserted and fixed to the second guide pin 306 of the second heat spreader 300 . Next, the first spreader 100 having the first guide pin 106 corresponding to the second guide pin 306 is safely mounted. The first heat spreader 100 is then fixed and coupled to the insertion hole 208 of the object 200 to be cooled.
[0040] Thus, by using the first guide pin 106 and the second guide pin 306 respectively of the first and second heat spreaders 100 and 300 , all the processes of fixing and coupling the first heat spreader 100 and the second heat spreader 300 to the object 200 to be cooled can be carried out by an automation process.
[0041] A coupling unit 600 that closely adheres and couples the first and second heat spreaders 100 and 300 to the object 200 to be cooled is installed on the heat sink according to the current embodiment of the present invention. The coupling unit 600 may be an elastic clip and is installed on a rear surface of the first and second heat spreaders 100 and 300 . The coupling unit 600 may also be securely coupled to a fixing portion 107 disposed on the first heat spreader 100 . Due to the coupling unit 600 , the formation of a space between the first through third components 202 , 204 , and 206 and the object 200 to be cooled is prevented.
Embodiment 2
[0042] FIG. 3 is a dissected perspective view illustrating a heat sink according to another embodiment of the present invention. FIG. 4 is a cross-sectional view of the heat sink illustrated in FIG. 3 , according to an embodiment of the present invention.
[0043] In detail, the heat sink according to the current embodiment of the present invention is substantially the same as the heat sink of FIG. 1 except that the third heat spreader 500 (shown in FIG. 2 ) is not installed on the surface of the first heat spreader 100 . In FIGS. 3 and 4 , the reference numerals identical to those of FIGS. 1 and 2 refer to identical components, and descriptions of the identical components, for example, the connection relationship and the effects, will be omitted.
[0044] Referring to FIGS. 3 and 4 , even though the third heat spreader 500 is not installed in a center portion 506 on the surface of the first heat spreader 100 , the heat sink of the current embodiment of the present invention can easily emit heat generated in first through third components 202 , 204 , 206 to the outside even with the absence of the third heat spreader 500 . In FIGS. 3 and 4 , a plurality of grooves 508 are formed on the upper surfaces of the first heat spreader 100 .
[0045] As such, the manufacturing process for the third heat spreader 500 can be omitted in the current embodiment of the present invention. A coupling unit 600 , e.g., an elastic clip, may again be used to closely adhere and couple the first and second heat spreaders 100 and 300 to the first through third components 202 , 204 , and 206 .
Embodiment 3
[0046] FIG. 5 is a dissected perspective view illustrating a heat sink according to another embodiment of the present invention. FIG. 6 is a cross-sectional view of the heat sink illustrated in FIG. 5 , according to an embodiment of the present invention.
[0047] In detail, the heat sink according to the current embodiment of the present invention is substantially identical to the heat sink of FIG. 1 except that first and second guide pins 106 a and 306 a of the current embodiment have a different shape than the first and second guide pins 106 and 306 of the heat sink of FIG. 1 . In FIGS. 5 and 6 , the reference numerals identical to those of FIGS. 1 and 2 refer to identical components, and descriptions of the identical components, for example, the connection relationship and the effects, will be omitted. In addition, a third heat spreader 500 is included in FIGS. 5 and 6 but may not be included according to necessity.
[0048] Referring to FIGS. 5 and 6 , first and second guide pins 106 a and 306 a according to the current embodiment of the present invention are respectively formed integrally with the first and second heat spreaders 100 and 300 of the heat sink of FIG. 1 and are bent shaped pins.
[0049] The first and second guide pins 106 a and 306 a according to the current embodiment of the present invention do not require a special manufacturing process and can be manufactured using a mold or a metal processing during the manufacture of the first and second heat spreaders 100 and 300 of the heat sink of FIG. 1 . Accordingly, the heat sink according to the current embodiment of the present invention can be manufactured in a simple process.
Embodiment 4
[0050] FIG. 7 is a dissected perspective view illustrating a heat sink according to another embodiment of the present invention. FIG. 8 is a cross-sectional view of the heat sink illustrated in FIG. 7 , according to an embodiment of the present invention.
[0051] In detail, the heat sink according to the current embodiment of the present invention is substantially identical to the heat sink of FIG. 1 except that first and second guide pins 106 b and 306 b of the current embodiment have a different shape than the first and second guide pins 106 and 306 of the heat sink of FIG. 1 . In FIGS. 7 and 8 , the reference numerals identical to those of FIGS. 1 and 2 refer to identical components, and descriptions of the identical components, for example, the connection relationship and the effects, will be omitted. In addition, a third heat spreader 500 is included in FIGS. 7 and 8 but may not be included according to necessity.
[0052] Referring to FIGS. 7 and 8 , the first and second guide pins 106 b and 306 b according to the current embodiment of the present invention are respectively formed integrally with the first and second heat spreaders 100 and 300 and are bent shaped pins. In addition, first and second guide pin supporting portions 110 and 310 that respectively support first and second guide pins 106 b and 306 b are included in the current embodiment of the present invention. When the first and second guide pin supporting portions 110 and 310 are included, the first and second guide pins 106 b and 306 b can be stably formed. Thus, even when first and second heat spreaders 100 and 300 are compressed by large external pressures, the first and second guide pins 106 b and 306 b may provide more support than the guide pins of the above described embodiments.
[0053] The first and second guide pins 106 b and 306 b and the first and second guide pin supporting portions 110 and 310 according to the current embodiment of the present invention do not require a special manufacturing process and can be manufactured using a mold or a metal processing during the manufacture of the first and second heat spreaders 100 and 300 of the heat sink of FIG. 1 . Accordingly, the heat sink according to the current embodiment of the present invention can be manufactured in a simple process.
Embodiment 5
[0054] FIG. 9 is a dissected perspective view illustrating a heat sink according to another embodiment of the present invention. FIG. 10 is a cross-sectional view of the heat sink illustrated in FIG. 9 , according to an embodiment of the present invention.
[0055] In detail, the heat sink according to the current embodiment of the present invention is substantially identical to the heat sink of FIG. 1 except that first and second supporting bars 114 and 314 supporting first and second heat spreaders 100 and 300 are installed. In FIGS. 9 and 10 , the reference numerals identical to those of FIGS. 1 and 2 refer to identical components, and descriptions of the identical components, for example, the connection relationship and the effects, will be omitted. In addition, a third heat spreader 500 is included in FIGS. 9 and 10 but may not be included according to necessity.
[0056] Referring to FIGS. 9 and 10 , the first and second supporting bars 114 and 314 supporting the first and second heat spreaders 100 and 300 may face and contact each other. The first and second supporting bars 114 and 314 may be installed on a rear surface or at a side surface of the first and second heat spreaders 100 and 300 . The first and second supporting bars 114 and 314 may be formed to contact the surface of the object 200 to be cooled, or may be separated from the object 200 to be cooled by a predetermined distance of about 0.1 to about 0.3 mm. The first and second supporting bars 114 and 314 and the first and second heat spreaders 100 and 300 may be installed to have a diverse size and shape according to the design of the first and second heat spreaders 100 and 300 . Thus, when the first and second supporting bars 114 and 314 supporting the first and second heat spreaders 100 and 300 are installed, the first and second heat spreaders 100 and 300 can be prevented from contacting the object 200 to be cooled even when the first and second heat spreaders 100 and 300 are pressed by external pressure.
[0057] The first and second supporting bars 114 and 314 do not require a special manufacturing process and can be manufactured using a mold or a metal processing as the manufacturing of the first and second heat spreaders 100 and 300 of the heat sink of FIG. 1 . Accordingly, the heat sink according to the current embodiment of the present invention can be manufactured in a simple process.
[0058] As described above, the heat sink may have various configurations according to various embodiments of the present invention. In addition, the components of the heat sink according to the various embodiments of the present invention can also be combined.
[0059] Hereinafter, a memory module using the heat sink according to embodiments of the present invention will be described. The printed circuit board (PCB) forming the memory module may correspond to the object to be cooled of the heat sink. Semiconductor packages forming the memory module may correspond to the first through third components disposed on the upper surface or the rear surface of the object that is to be cooled. Hereinafter, a memory module in which the heat sink of FIG. 1 is described. However, the heat sink according to the other embodiments or a combination thereof may also be used by the memory module.
[0060] Memory Module
Embodiment 6
[0061] FIG. 11 is a plan view of a memory module 400 employing a heat sink, according to an embodiment of the present invention, and FIGS. 12 and 13 are a cross-sectional view and a perspective view of a memory module employing a heat sink according to another embodiment of the present invention.
[0062] A heat sink is formed on an upper surface and a rear surface of the bare memory module 400 . The bare memory module 400 includes a plurality of first and second semiconductor packages 404 and 406 (not shown in FIGS. 11 and 13 ) attached to a PCB 402 , an advanced memory buffer (AMB) 408 , a circuit element 410 , for example, a capacitor, and a contact pad 412 contacting a mother board (not shown).
[0063] The bare memory module 400 can be classified as a single in-lined memory module (SIMM) in which semiconductor packages 404 are attached on only one surface of the PCB 402 , a dual in-lined memory module (DIMM) in which semiconductor packages 404 and 406 are attached on both sides of the PCB 402 , and a fully buffered dual in-lined memory module (FBDIMM) in which AMB 408 is further attached in the center portion of the surface of the PCB 402 .
[0064] FIGS. 11 through 13 illustrate the FBFIMM as the bare memory module 400 . In FIGS. 11 through 13 , the number of semiconductor packages attached on the PCB 402 can vary according to the design or the capacity of the memory. In the bare memory module 400 , signals from the outside pass through the AMB 408 and are transmitted to the first and second semiconductor packages 404 and 406 in order to increase the transmission efficiency of the bare memory module 400 . Thus, a large load is concentrated on the AMB 408 , and more intense heat is generated in the AMB 408 than in other first and second semiconductor packages 404 or 406 .
[0065] In particular, a lot more semiconductor packages can be mounted in the FBDIMM bare memory module 400 to increase the memory capacity and to increase the transmission efficiency of the FBDIMM bare memory module 400 . Thus, a non-circuit region is present only near both edges of the PCB 402 where an insertion hole 208 can be formed. The insertion hole 208 may have a diameter of about 1.5 mm. The insertion hole 208 may or may not pass through the object 200 to be cooled. As described with reference to the heat sink of FIG. 1 , the first and second guide pins 106 and 306 may be formed in the extension portions 104 and 304 (as shown in FIGS. 1 and 2 ) near both edges of the first and second heat spreaders 100 and 300 . Also, since intense heat may be generated in the AMB 408 , a third heat spreader 500 may be needed to emit heat more easily.
[0066] Referring to FIGS. 11 and 12 , the first semiconductor packages 404 are mounted on the upper surface of the PCB 402 . The first semiconductor packages 404 correspond to the first components 202 of the heat sink of FIG. 1 . The second semiconductor packages 406 are mounted on a rear surface of the PCB 402 . The second semiconductor packages 406 correspond to the second components 204 of the heat sink of FIG. 1 . The AMB 408 is mounted in the center portion of the surface of the PCB 402 . The AMB 408 corresponds to the third component 206 of the heat sink of FIG. 1 .
[0067] The first and second semiconductor packages 404 and 406 may include a semiconductor chip, a mold surrounding the semiconductor chip, and solder balls arranged on a rear surface of the mold that are electrically connected to the semiconductor chip. The mold passes the thermal interface layers 108 and 308 to face and contact the first and second heat spreaders 100 and 300 . The first and second semiconductor packages 404 and 406 may be a ball grid array (BGA) package, a chip scale package (CSP), a wafer level package (WLP), etc.
[0068] The first heat spreader 100 faces and contacts the first semiconductor packages 404 and emits heat from the first semiconductor packages 404 . The second heat spreader 300 faces and contacts the second semiconductor packages 406 and emits heat from the second semiconductor packages 406 . The first guide pin 106 that is inserted in the insertion hole 208 formed on the PCB 402 is fixed in the first extension portion 104 near both edges of the first heat spreader 100 .
[0069] Facing the first guide pin 106 , the second guide pin 306 that is inserted in the insertion hole 208 is fixed in a second extension portion 304 near both edges of the second heat spreader 300 . The first and second extension portions 104 and 304 may not respectively face and contact the first and second semiconductor packages 404 and 406 , but may still correspond to the insertion hole 208 of the PCB 402 .
[0070] The first and second guide pins 106 and 306 may be separated by a predetermined distance from each other in the insertion hole 208 of the PCB 402 . The first and second guide pins 106 and 306 may be forcibly inserted and fixed in the insertion hole 208 of the PCB 402 . Heat in the AMB 408 is dissipated through the third heat spreader 500 attached to the first heat spreader 100 on the AMB 408 . The first heat spreader 100 and the second heat spreader 300 are closely adhered and coupled to the PCB 402 by a coupling unit 600 , which may be an elastic clip.
[0071] Method of Manufacturing Guide Pins
[0072] FIGS. 14 and 15 are schematic views illustrating a method of combining guide pins to a heat spreader, according to an embodiment of the present invention.
[0073] Referring to FIG. 14 , the guide pins 106 or 306 , such as pen pins having a diameter of about 1.2 mm, are provided. Then holes 116 or 316 are formed in the heat spreader 100 or 300 . The guide pins 106 or 306 are inserted into the holes 116 or 316 of the first or second heat spreaders 100 or 300 . The guide pins 106 or 306 that are inserted in the holes 116 or 316 of the first and second heat spreaders 100 and 300 are loaded in a compression processing apparatus having a punch 602 and a die 604 .
[0074] Referring to FIG. 15 , an upper portion of the guide pins 106 or 306 that is inserted in the holes 116 or 316 of the heat spreaders 100 or 300 is processed using the compression processing apparatus. Thus the guide pins 106 or 306 are inserted and fixed in the holes 116 or 316 of the heat spreaders 100 or 300 .
[0075] While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the spirit and scope of the present invention as defined by the following claims.
[0076] As described above, a heat sink according to the present invention includes guide pins inserted and fixed in insertion holes which are formed in extension portions near both edges of first and second heat spreaders and installed in an object to be cooled. Thus when the first heat spreader and the second heat spreader are coupled, a misalignment between the first heat spreader and the second heat spreader does not occur, and an automation process is possible.
[0077] The heat sink according to the present invention is inserted and fixed in the insertion hole of the object to be cooled, and thus the first and second heat spreaders can be prevented from contacting each other when the first and second heat spreaders are pressed by pressure applied from the outside.
[0078] The heat sink according to the present invention may also include a third heat spreader that is attached on the first heat spreader and has an excellent heat transfer coefficient to efficiently emit heat regardless of the amount of heat generated in the object to be cooled.
[0079] When the heat sink according to the present invention is employed in a memory module, a misalignment between the first and second heat spreaders is prevented when the first and second heat spreaders that are disposed on an upper surface and a rear surface of a PCB are coupled, and as such, an automation process is possible.
[0080] When the heat sink according to the present invention is employed, the first heat spreader or the second heat spreader can be prevented from contacting a circuit element formed on the PCB, for example, a capacitor, when the first and second heat spreaders are pressed by pressure applied from the outside. | Provided are a heat sink and a memory module using the heat sink. In one embodiment, the heat sink includes a first and second guide pin respectively disposed in first and second heat spreaders placed around an object to be cooled. The first and second guide pins help prevent misalignment problems from occurring between the first and second heat spreaders, as well, as helping prevent the first and second heat spreaders from contacting each other when the first and second heat spreaders are pressed by pressure applied from the outside. | 7 |
CROSS-REFERENCE TO RELATED APPLICATION
This application claims the benefit of earlier filed U.S. Provisional Patent Application Ser. No. 60/153,860, filed Sep. 14, 1999 entitled “Grit Surface Cable Products.”
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to mine roof cable bolts and, more particularly, to coated mine roof cable bolts that are configured to be resin grouted.
2. Brief Description of the Prior Art
A mine roof may be supported by a cable bolt positioned inside a bore hole in a mine roof and resin grouted into place. Examples of mine roof cable bolts are disclosed in U.S. Pat. No. 5,259,703 to Gillespie, U.S. Pat. Nos. 5,375,946 and 5,378,087 both to Locotos, and U.S. Pat. No. 6,074,134 to Stankus et al., herein incorporated by reference.
Cable bolts typically include a single or multi-strand cable segment, a drive head positioned on a first end of the cable segment. A plurality of mixing devices may be positioned along a longitudinal axis of the cable segment, and a stiffening sleeve may be positioned adjacent the first end of the cable segment. These prior art mine roof cable bolts may be tensionable and include one or more mixing devices thereon.
During installation of a cable bolt and mine roof plate system, the first end of a cable segment is generally positioned adjacent a mine roof plate, with the second end inserted into a bore hole created in the earth and rock adjacent a mine roof. Also inserted into the bore hole is a resin catalyst and an adhesive. The cable segment is rotated after insertion, causing the mixing devices to mix the resin catalyst and adhesive. The mixing devices also distribute the adhesive within the rock, in the cracks and crevices between individual strands of a multi-strand cable segment, and in voids between an outer surface of the cable segment and an inner wall of the bore hole. Once cured, the adhesive helps to anchor the cable segment to the earth and rock. Tensionable cable bolts are installed in a similar manner, except that an expansion assembly may also be included to further secure the cable bolt inside the bore hole and tension the bolt between the mine roof and the expansion assembly.
One universal drawback of the cable bolt and mine roof plate systems of the prior art is the trouble and expense associated with incorporating mixing devices, such as nut cages, buttons, or birdcages, into a cable segment. Another drawback is the stiffening sleeve positioned adjacent a first end of the cable segment. In theory, stiffening sleeves help protect the cable segment and prevent the cable bolt from kinking during insertion. However, stiffening sleeves do not prevent torsional deformation of the portion of the bolt not secured in the resin caused when torque is applied to the bolt drive head. When torque is applied during installation of the bolt to mix resin and/or engage a mechanical anchor, a second end of the cable segment decreases rotation as the mechanical anchor and resin restrain movement while the first end is unencumbered. This tends to cause twisting of the cable segment in the portion of the cable bolt between the mine roof and the resin. When installation is complete and torque from the bolt installation machine is removed, the twists in the non-resin grouted portion of the cable untwist which causes the tension applied to the bolt to be reduced. To counteract the twisting of the lower (ungrouted) portion of the cable, a plurality of sleeves or “buttons” are fixed to the cable lower portion. However, these additional components add to the cost of manufacturing a tensionable cable bolt.
Mixing devices and stiffening sleeves increase manufacturing costs, increase the risk of producing nonconforming goods, and do not prevent torsional deformation. Hence, a need remains for a mine roof cable bolt which resists torsional deformation during installation with subsequent loss of tension, while eliminating or minimizing the need for such extraneous mixing devices and/or stiffening sleeves.
SUMMARY OF THE INVENTION
To obviate the deficiencies of the prior art, one embodiment of the present invention generally includes a cable bolt having a coated cable segment. The cable segment generally includes a first end and a second end with a drive head positioned adjacent the first end of the cable segment.
In single cable segments, the coating is positioned adjacent an exterior surface of the cable segment coating all or only a portion of the exterior surface. In multi-strand cable segments, the coating may completely or partially coat an exterior surface of each strand. Positioned adjacent an exterior surface of the coating are particulates forming a textured surface on the exterior of the cable bolt. A tensioning device may also be positioned along a longitudinal axis of the cable segment. The coating serves three primary functions. First, the coating strengthens the cable segment eliminating the need for a stiffening sleeve in some applications. Second, the coating retards torsional deformation of the cable segment bearing the coating when torque is applied to the drive head. Third, the coating further provides an attachment medium for the particulates. The particulates increase the overall surface area of the cable segment providing more bonding area for the resin and providing agitation of the resin catalyst and adhesive during mixing. The particulates, therefore, reduce the need for mixing devices, such as bulbs and birdcages, in some applications.
It is therefore an object of the present invention to provide a cable bolt that resists torsional deformation, does not require a stiffening sleeve, and in some applications, traditional mixing devices.
These and other advantages of the present invention will be clarified in the Detailed Description of the Preferred Embodiments and the attached figures in which like reference numerals represent like elements throughout.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side view of a prior art cable bolt having a multi-strand cable, birdcages, and a stiffening sleeve inserted into a cross-sectional view of a bore hole;
FIG. 2 is a side view of one embodiment of the cable bolt of the present invention inserted into a cross-sectional view of a bore hole;
FIG. 3 is a side view of a second embodiment of the cable bolt of the present invention inserted into a cross-sectional view of a bore hole;
FIG. 4 is a side view of a third embodiment of the cable bolt of the present invention inserted into a cross-sectional view of a bore hole;
FIG. 5 is a side view of a fourth embodiment of the cable bolt of the present invention inserted into a cross-sectional view of a bore hole; and
FIG. 6 is a perspective view of a horizontally sectional multi-strand cable segment, as shown in FIG. 2 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The preferred embodiment of the cable bolt of the present invention is generally shown in FIG. 2 . For purposes of introduction, a prior art device shown in FIG. 1 will be discussed first.
FIG. 1 shows a typical prior art cable bolt C installed in a bore hole B. The cable bolt C generally includes a multi-strand M cable segment S, birdcages G formed in a second end E of cable segment S, a stiffening sleeve L positioned adjacent a first end F of the cable segment S, and a drive head H positioned adjacent the first end F of the cable segment S. The cable bolt C preferably is installed in a mine roof with a mine roof plate P positioned adjacent the drive head H and resin or adhesive A placed at the blind end of the bore hole B between an exterior surface ES of the cable bolt C and an interior surface IS of the bore hole B. Alternatively, the resin and adhesive A may fill all or nearly all of the bore hole B not occupied by the cable bolt C.
As shown in FIG. 2, the cable bolt 10 of the present invention includes a cable segment 14 , preferably, multi-strand cable 16 constructed from steel or other suitable material installed in a borehole 12 with a bearing plate 28 . The cable segment 14 has a drive head 26 with a conventional load bearing barrel and wedge assembly 52 positioned on a first end 24 of the cable segment 14 and is coated with a layer of a rigid or semi-rigid coating material 36 , such as plastic, epoxy, resin, or other suitable material. A suitable assembly of drive head 26 with barrel and wedge assembly 52 is disclosed in U.S. Pat. No. 5,829,922 to Calandra, Jr. et al., incorporated herein by reference. The entire length of cable segment 14 is preferably coated, as shown in FIG. 2, but partial coating is also envisioned.
As shown in detail in FIG. 6, coating material 36 preferably includes an epoxy material and a plurality of particulates 40 , such as grit, sand, rock, diamond dust, or other suitable material dispersed in the epoxy material either on the surface thereof or through the thickness of the coating material 36 . The individual particulates 40 should be large enough in diameter to give the exterior surface of the coating material 36 covering the cable segment 14 a textured appearance and feel, but not large enough to significantly alter the overall diameter of the cable segment 14 . The coating material 36 preferably is of the type disclosed in U.S. Pat. No. 5,208,777 to Proctor et al., incorporated herein by reference.
It should be apparent to those in the art that the coating material 36 and the particulates 40 need not be two distinct substances provided the coating material 36 forms a textured exterior surface and, preferably, makes the cable segment 14 more rigid.
The coating material 36 adds rigidity to the cable segment 14 , eliminating the need for a stiffening sleeve L, shown in FIG. 1, and reducing torsional rotation in tensionable cable bolts 10 ′ and 10 ″, shown in FIGS. 3 and 4. The coating material 36 also provides a surface of adhesion between resin in a bore hole 12 and the particulates 40 . The particulates 40 increase the total exterior surface area of the cable segment 14 which increases the resin catalyst and adhesive 30 bonding area. More importantly, the particulates 40 increase agitation of the resin catalyst and adhesive 30 when the cable segment 14 is rotated in the bore hole 12 during mixing of the resin catalyst and adhesive 30 . This agitation eliminates the need for adding birdcages or other traditional mixing devices to cable bolts 10 inserted into smaller bore holes 12 , such as those approximately one inch or smaller in diameter.
In a second embodiment, shown generally in FIGS. 3 and 4, the cable bolts 10 ′ and 10 ″ include the cable segment 14 with the coating material 36 and a mechanical anchor 44 threaded onto an externally threaded sleeve 46 surrounding the second end 20 of the cable segment 14 (FIG. 4) as disclosed in U.S. patent application Ser. No. 09/384,524, filed Aug. 27, 1999, entitled “Tensionable Cable Bolt,” which is a continuation-in-part of the application resulting in the '134 patent, incorporated herein by reference. Alternatively, the mechanical anchor 44 and sleeve 46 may be located at a position intermediate the first end 24 and the second end 20 of the cable bolt 10 ″, also shown in FIG. 3 .
In a third embodiment, shown in FIG. 5, the cable bolt 10 ′″ includes at least one sleeve or “button” 18 surrounding the cable segment 14 at a position intermediate the first and second ends 24 , 20 of the cable segment 14 . Preferably, a plurality of buttons 18 are included on cable bolt 10 ′″. The buttons 18 may include longitudinal flanges or wings 54 to increase the resin holding surface area thereof. The embodiment shown in FIG. 5 is used in larger bore holes 12 , such as those in the range of one and three-eighths inches diameter or larger. It is believed that in bore holes 12 of one inch in diameter, the cable bolts do not require any additional mixing device beyond the coating material 36 , as shown in FIG. 2 .
The installation process for the cable bolts 10 , 10 ′, 10 ″, and 10 ′″ generally includes the steps of partially or completely coating a cable segment 14 with a textured surface, preferably, using a coating material 36 as described above; drilling a bore hole 12 in a mine roof; inserting resin in the form of two-part catalyst and hardenable component packages into the bore hole 12 ; inserting a second end 20 of the coated cable segment 14 into the bore hole 12 to rupture the catalyst and hardenable component packages; mixing the resin catalyst and adhesive 30 by rotating the coated cable segment 14 via mine roof bolt installation equipment attached to the drive head 26 ; and allowing the resin 30 to cure. For the cable bolts 10 ′ and 10 ″, rotation of the bolt also causes expansion of the mechanical anchor 44 which engages with and grips the interior surface 34 of the wall surrounding the bore hole 12 . Torsional deformation of the cable segment is significantly reduced and cable bolts 10 ′ and 10 ″ may be tensioned as described in the above-mentioned patents and patent applications. It has been found that the coating material 36 sufficiently stiffens the cable segment 14 which is below the resin 30 to prevent twisting of the cable segment 14 during installation and tension loss upon release of the bolts 10 ′ and 10 ″ from installation equipment.
It is believed that rotation of the cable segment 14 with the coating material 36 sufficiently mixes resin in a one-inch bore hole 12 . The particulates 40 embedded in the epoxy material of the coating material 36 provide enhanced mixing over uncoated cable. In addition, the increased surface area of the cable bolts 10 , 10 ′, 10 ″, and 10 ′″ of the present invention over uncoated cable segments 14 creates higher holding strength with the resin. In pull tests, cable bolts according to the present invention resisted deflection when subjected to pull forces of between 20 and 29 tons. Hence, the present invention includes a cable bolt coated with a textured material without any alteration to the wrapped strands of the cable segment 14 , such as birdcages, nutcages, or bulbs and also includes a method of installing the inventive cable bolt in resin containing bore holes. For larger diameter bore holes (e.g., one and three-eighths inches), altered cable again is believed to be unnecessary to achieve sufficient resin and adhesive 30 mixing and bonding. However, in certain circumstances simple mixing devices, such as buttons, are required as shown in FIG. 5 .
The present invention eliminates the need for a stiffening sleeve L, traditional mixing devices, such as birdcages, or both from conventional mine roof cable bolts while still retarding torsional rotation (in tensionable cable bolts). The textured surface of the cable segment 14 serves to mix the resin 30 , provide increased bonding area on the cable segment 14 , and increase friction between the resin 30 and the cable bolts 10 , 10 ′, 10 ″, and 10 ′″. Moreover, torsional rotation of cable segments 14 in tensionable cable bolts 10 ′ and 10 ″ is reduced within.
The invention has been described with reference to the preferred embodiments. Obvious modifications and alterations will occur to others upon reading and understanding the preceding detailed description. It is intended that the invention be construed as including all such modifications and alterations. | A mine roof bolt, preferably one inch or less in diameter, having an external coating configured with particles which mix resin as the mine roof bolt is rotated in a mine roof bore hole. | 4 |
The present application is a U.S. National Phase filing of International Application No. PCT/FR2012/051721, filed on Jul. 19, 2012, designating the United States of America and claiming priority to French patent application No. 1156641, filed Jul. 21, 2011, and this application claims priority to and the benefit of the above-identified applications, which are both incorporated by reference herein in their entireties.
FIELD
The disclosure generally relates to a system for dispensing a fluid product packaged in a bottle.
BACKGROUND
In one particular application, the product is of the gel or cream type, for example for use in cosmetics or for pharmaceutical treatments. More particularly, the example dispensing system may be suitable for the application of a product such as a lip gloss or a lip care product.
Dispensing systems comprising a member for extracting a product packaged in a bottle are known, for example consisting of a pump, which has a body rigidly connected to said bottle in order to be supplied with product and a nozzle over said body. In particular, the extracting member is suitable for being actuated by means of reversible movement of the nozzle along a downward and upward axial stroke for product dispensing and intake, respectively.
Conventionally, the movement of the nozzle is actuated by a push button which is mounted on the upper end of the nozzle, said push button having a dispensing orifice connected to said nozzle and an upper axial bearing area.
The document KR-2010/001 0657 envisages a laterally mounted push button in relation to the nozzle of a pump, said push button interacting with two ribs formed on said nozzle so that a radial movement of said push button causes an engagement of said nozzle along the dispensing stroke thereof.
SUMMARY
In one example, a dispensing system can include a lateral actuation of an extracting member by means of a push button, wherein the stroke and the actuation force may be reduced, said system optionally using a standard extracting member, i.e. of the type suitable for use for axial actuation.
For this purpose, the an example embodiment relates to a system for dispensing a fluid product packaged in a bottle, said system comprising a member for extracting the packaged product having a body rigidly connected to the bottle in order to be supplied with product and a nozzle over said body, said nozzle being suitable for moving reversibly along a downward and upward axial stroke for product dispensing and intake, respectively, said system may include:
a ring rigidly connected to the bottle and wherein the body of the member is secured tightly, said ring having two upper arms arranged on either side of the nozzle which is equipped with two outer pins, said arms each having an inner pin arranged in the axial extension of an outer pin to form a housing together; a supporting member having an orifice for dispensing the product, the arms being mounted in translation in said supporting member by connecting the nozzle with the dispensing orifice; a push button for actuating the extracting member which is mounted in radial translation in relation to the supporting member, said push button having two tabs arranged respectively in a housing formed between the pins, said tabs each having an upper bearing surface bearing on an inner pin and a lower bearing surface bearing on an outer pin, said bearing surfaces being radially divergent so that engaging the push button causes separation of the pins to actuate the extracting member by engaging the nozzle and lifting the bottle.
BRIEF DESCRIPTION OF THE DRAWINGS
Further aims and advantages of the disclosure will emerge in the following description, with reference to the appended figures, wherein:
FIGS. 1-1 c is an exploded perspective view of a dispensing system according to a first embodiment of the invention, FIGS. 1 a , 1 b and 1 c being enlarged views of the push button, the supporting member and the ring shown in FIG. 1 , respectively;
FIGS. 2 a - 2 b are longitudinal sectional views of the dispensing system according to FIG. 1 , with the push button in the idle ( FIG. 2 a ) and engaged ( FIG. 2 b ) position, respectively;
FIGS. 3 a - 3 b are partial perspective views showing the dispensing system according to FIG. 1 without its case thereof, with the push button in the idle ( FIG. 3 a ) and engaged ( FIG. 3 b ) position, respectively;
FIGS. 4 a - 4 b are longitudinal sections of FIGS. 3 a and 3 b;
FIGS. 5 a - 5 b are cross-sectional views showing the dispensing system according to FIG. 1 with the push button in the idle ( FIG. 5 a ) and engaged ( FIG. 5 b ) position, respectively;
FIG. 6 illustrates the steps for assembling the dispensing system according to FIG. 1 ;
FIG. 7 illustrates steps for packaging the product and finishing the assembly of the dispensing system according to FIG. 1 ;
FIGS. 8-8 d is an exploded perspective view of a dispensing system according to a second embodiment of the invention, FIGS. 8 a , 8 b , 8 c and 8 d being enlarged views of the application means-supporting member assembly, push button, ring and tip shown in FIG. 8 , respectively;
FIGS. 9 a - 9 d represent the dispensing system according to FIG. 8 with the push button in the idle position, in a cross-section ( FIG. 9 a ), partially in a perspective view without the supporting member ( FIG. 9 b ) and in a longitudinal section ( FIGS. 9 c and 9 d ), respectively;
FIGS. 10 a - 10 d represent the dispensing system according to FIG. 8 with the push button in the engaged position, in a cross-section ( FIG. 10 a ), partially in a perspective view without the supporting member ( FIG. 10 b ) and in a longitudinal section ( FIGS. 10 c and 10 d ), respectively.
DETAILED DESCRIPTION
In relation to the figures, a system for dispensing a fluid product packaged in a bottle 1 is described, said product optionally being a gel or a cream, for example for cosmetic use or for pharmaceutical treatments.
The system comprises a member 2 for extracting the packaged product having a body rigidly connected to the bottle 1 in order to be supplied with product and a nozzle 3 over said body. In the embodiment shown, the sampling member is a pump 2 without the invention being restricted to such an embodiment, said pump optionally being of the type without air return while being supplied with product, for example, by actuating a scraper piston sliding in the bottle 1 .
To enable extraction of the product, the nozzle 3 is suitable for moving reversibly along a downward and upward axial stroke for product dispensing and intake, respectively. In particular, the nozzle 3 may comprise a tube which is arranged in the body of the pump 2 by forming a metering chamber connected to the bottle 1 via a flap, a spring 4 being provided to return said nozzle along the intake stroke thereof.
In relation to FIG. 4 wherein it is sectioned, the pump 2 is of the type described in the document FR-2 908 843, i.e. comprising a needle valve 5 arranged in the nozzle 3 to open, or close, the connection between said nozzle and the metering chamber along the dispensing, or intake, stroke. However, the invention is not restricted to a particular pump 2 structure, particularly in relation to the means required for pressurised extraction of the product to be dispensed.
The system comprises a ring 6 rigidly connected to the bottle 1 and wherein the body of the pump 2 is secured tightly. For this purpose, the ring 6 has a tubular portion 6 a wherein the body of the pump 2 is mounted by means of tight fitting.
In the embodiment shown in FIG. 1 , the bottle 1 comprises a receptacle 1 a which is joined under the ring 6 , said ring having a lower bearing surface 6 b whereon the upper opening of the receptacle 1 a is mounted tightly to connect the pump 2 to the inside of said receptacle. In an alternative embodiment not shown, the ring 6 may be formed of one piece along the upper portion of the bottle 1 which then comprises a mounted base to seal said bottle after the filling thereof with product.
The ring 6 has two upper arms 7 which are arranged on either side of the nozzle 3 . In FIG. 1 , the arms 7 are integral with the tubular portion 6 a being joined along the upper edge thereof by means of a hinge 8 . This embodiment enables the arrangement of the arms 7 between a separated position ( FIG. 1 c ) wherein the pump 2 can be secured in the tubular portion 6 a and a position encompassing the nozzle 3 .
The nozzle 3 is equipped with two outer pins 9 and the arms 7 each have an inner pin 10 arranged over and axially extending from an outer pin 9 to form a housing together. In the embodiments shown, the nozzle 3 is equipped with a mounted tip 11 whereon the outer pins 9 are formed. In particular, the tip 11 has a hole for mounting on the nozzle 3 , the pins 9 extending radially while being diametrically distributed about said hole. In an alternative embodiment not shown, the pins 9 may be formed directly on the nozzle 3 .
Moreover, the inner pins 10 extend radially while being formed in the vicinity of the upper ends of the arms 7 , each of said arms having an axial groove 12 wherein an outer pin 9 is guided in translation.
The system comprises a supporting member 13 which has an orifice 14 for dispensing the product, the arms 7 being mounted in translation in said supporting member by connecting the nozzle 3 to the dispensing orifice 14 . In the first embodiment, the upper ends of the arms 7 each have an outer edge 15 , formed opposite the pins 10 , said edge being guided in translation in a U-bolt 16 of the supporting member 13 . In particular, the outer edges 15 have a bevelled end suitable for the arrangement thereof in U-bolts 16 by relative sliding of the supporting member 13 in relation to the ring 6 and a straight bottom side to prevent subsequent retraction thereof.
The system comprises a push button 17 for actuating the extracting member 2 which is mounted in radial translation in relation to the supporting member 13 . For this purpose, the supporting member 13 has a front side wall 18 which is provided with an orifice 19 wherein the push button 17 is mounted, the U-bolts 16 being formed on either side of said wall ( FIG. 1 ).
The push button 17 has two tabs 20 respectively arranged in a housing formed between the pins 9 , 10 , said tabs extending radially in the orifice 19 to be arranged respectively between an arm 7 and the tip 11 , said tabs encompassing the nozzle 3 . The tabs 20 each have an upper bearing surface 20 a bearing on an inner pin 10 and a lower bearing surface 20 b bearing on an outer pin 9 , said bearing surfaces being radially divergent so that engaging the push button 17 causes separation of the pins 9 , 10 .
In this way, the extracting member 2 is actuated by combining engagement of the nozzle 3 with lifting of the bottle 1 , making it possible to limit the stroke and the actuation force of the push button 17 in translation. Furthermore, after releasing the push button 17 , the return of the nozzle 3 along the intake stroke thereof actuates the return of the push button 17 and the bottle 1 to the idle position. According to one example of an embodiment, the bearing surfaces 20 a , 20 b have a slope of 35° in order to, along a stroke less than 3.5 mm, dispense a dose in the region of 120 μl.
In the embodiments shown, the tabs 20 have a top face and a bottom face, each of said faces comprising a recess 21 bordered to the front by an outer edge 22 and to the rear by a bearing surface 20 a , 20 b . In this way, the idle position of the push button 17 is defined by arranging a pin 9 , 10 respectively in a recess 21 of a size substantially equal to that of said pin.
The outer edges 22 have a bevelled end suitable for arranging the tabs 20 in housings formed between the pins 9 , 10 . In particular, for this arrangement, the pins 9 , 10 are separated by bearing on the edges 22 , causing actuation of the pump 2 suitable for example for use for pre-priming same.
Moreover, the pins 9 , 10 interact with an outer edge 22 to prevent the retraction of the push button 17 . For this purpose, the outer edges 22 have a straight rear side to prevent the retraction of the pins 9 , 10 after the arrangement thereof in the recesses 21 .
To guide the push button 17 in translation, each tab 20 has a central recess 23 wherein a radial slide 24 formed in the supporting member 13 is arranged. Furthermore, this embodiment is suitable for ensuring reliable transmission of the forces between the bearing surfaces 20 a , 20 b and the pins 9 , 10 during the translation of the push button 17 .
In relation to FIG. 5 , the supporting member 13 has a wall 25 formed opposite the push button 17 , said wall having a complementary geometry to that of a rear portion of the nozzle 3 arranged facing same. In this way, on actuation, the wall 25 is suitable for limiting any misalignment of the nozzle 3 by bearing said nozzle on said wall.
Furthermore, the supporting member 13 has at least one abutment 26 defining the end-of-travel position in respect of translation of the push button 17 , this abutment 26 being suitable in particular for being readily arranged to determine the dispensed dose. In particular, the wall 25 is bordered by two radial flanks 27 against which a tab 20 respectively slides, said flanks having a base acting as the abutment 26 .
In relation to the first embodiment, the system comprises a case 28 which is joined to the supporting member 13 , particularly around the wall 18 and the U-bolts 16 , to encompass the bottle 1 , said case having a side orifice 29 arranged opposite the orifice 19 of the supporting member 13 and via which the push button 17 is accessible. In particular, the case 28 may be arranged to enhance the design of the system, an inner cap 30 optionally being provided under said case to completely conceal the bottle 1 . Furthermore, the push button 17 may be encompassed by a trimming cover for concealing the edge of the orifice 29 .
The system may comprise means for applying the product, said means being mounted on the dispensing orifice 14 . In the first embodiment, the means are formed from a deformable sleeve 31 having an upper slot 32 suitable for opening under the pressure of the dispensed product.
This embodiment is particularly suitable for applying a product such as a lip gloss or a lip care product. Advantageously, at least the slot 32 of the sleeve 31 may be loaded with an antibacterial agent, for example based on silver, such as Alphasan or Bactiglas so as to prevent the penetration of micro-organisms through the product film clamped at said slot. Alternatively, a brush or further means for applying a product may be provided.
The supporting member 13 may comprise means for indexing the angular position of the application means in relation to the push button 17 . In the first embodiment, the sleeve 31 comprises a lower collar 31 a held around the dispensing orifice 14 by an inner bearing surface 28 a of the case 28 , the slot 32 projecting from said case. The collar 31 a has two axial slots 31 b wherein a knurl 13 a of the supporting member 13 is engaged for indexing.
Advantageously, the supporting member 13 has an inner conduit 33 topped by the dispensing orifice 14 and the nozzle 3 has an upper shaft 34 tightly slidably mounted in said conduit. In particular, the tip 11 comprises an upper portion wherein the shaft 34 is formed by connecting to the nozzle 3 .
This embodiment is suitable for defining in the conduit 33 a buffer chamber 35 for the extracted product for which the volume increases, or decreases, along the dispensing, or intake, stroke, of the nozzle 3 . In particular, the buffer chamber 35 comprises a cylindrical lower portion wherein the shaft 34 is slidably mounted and a conical upper portion converging towards the dispensing orifice 14 . The buffer chamber 35 may have a variation in volume between 30% and 100% of the dose of product extracted by the pump 2 .
In this way, it is possible to obtain a movement wherein dispensing is at least partly dissociated from the application of the product. Indeed, pressing the push button 17 causes the buffer chamber 35 to fill with at least a portion of the extracted dose and, after releasing said push button, the dose is dispensed through the slot 32 by reducing the volume in said buffer chamber.
In relation to FIG. 6 , various steps for assembling the dispensing system are described hereinafter, wherein the arms 7 are arranged in the separated position ( FIG. 6.1 ) to secure the pump 2 in the ring 6 ( FIG. 6.2 ). The tip 11 is then mounted on the nozzle 3 ( FIG. 6.3 ) and the arms 7 are pulled back ( FIG. 6.4 ) to the position encompassing the nozzle 3 with the outer pins 9 arranged in the slots 12 ( FIG. 6.5 ).
The supporting member 13 is then arranged around the arms 7 by arranging the outer edges 15 in the U-bolts 16 ( FIG. 6.6 ) and the sleeve 31 is mounted onto said supporting member ( FIG. 6.7 ). The case 28 may then be mounted about the supporting member 13 and the bottle 1 ( FIG. 6.8 ) followed by the push button 17 in the orifices 19 , 29 with the tabs 20 in the housings formed between the pins 9 , 10 ( FIG. 6.9 ). A cap 36 is then mounted around the supporting member 13 to protect the sleeve 31 between two applications ( FIG. 6.10 ).
Following these steps, the dispensing system is in delivery condition and FIG. 7 illustrates various steps for packaging the product and finishing the assembly of the dispensing system.
FIGS. 7.1 and 7 . 2 show filling of the receptacle 1 a with product by means of a tube 37 , said receptacle then being associated under the ring 6 of the system in delivery condition ( FIGS. 7.3 and 7 . 4 ). The cap 30 of the case 28 may then be mounted to finalise the dispensing system ( FIGS. 7.5 and 7 . 6 ).
In relation to FIGS. 8 to 10 , a second embodiment of a dispensing system is described hereinafter, wherein the supporting member 13 comprises an insert 40 secured inside said supporting member, said insert having the inner conduit 33 topped by the dispensing orifice 14 . As in the first embodiment, the upper shaft 34 of the tip 11 is tightly slidably mounted in the conduit 33 to define the buffer chamber 35 .
The dispensing system also comprises a receptacle 1 a joined under the body of the extracting member 2 , a connector 41 being provided to ensure tightness of this assembly. Moreover, a case 28 is secured under the supporting member 13 which has a lower bearing surface 13 b for this purpose.
The insert 40 has an upper plate 42 whereon a cone 43 topped by the dispensing orifice 14 extends, said plate having four notches 44 distributed in pairs on either side of the cone 43 , said notches being engaged respectively in an axial groove 45 formed inside the supporting member 13 .
The grooves 45 are suitable for straight mounting of the insert 40 by sliding inside the supporting member 13 until the plate 42 is secured in said supporting member, particularly by locking. Furthermore, the insert 40 has a U-shaped bridge 46 formed between each of the pairs of notches 44 to enhance the slidable guiding of the insert 40 in the supporting member 13 , particularly by limiting the rotation of said insert before locking.
The insert 40 also has two axial slots 47 formed respectively under a U-shaped bridge 46 , an inner pin 10 being guided in translation in respectively a slot 47 upon actuation of the system. In particular, the arms 7 are integral with the tubular portion 6 a while being fixedly joined on the upper edge thereof. Moreover, the arms 7 are guided in translation in the supporting member 13 between two grooves 45 .
The lower end of each of the edges of the slots 47 is equipped with a pin 48 . In particular, the two pins 48 of a slot 47 act as the radial slide 24 for guiding the push button 17 in translation via the central recess 23 .
In the second embodiment, the application means comprise an element 49 wherein a conduit 50 is formed, extending from a base 51 to a tip wherein it opens onto a lateral application surface 52 . The base 51 is equipped with reversible joining means on the supporting member 13 by placing the dispensing orifice 14 in the conduit 50 . In FIGS. 8 to 10 , the joining means comprise two blocks 53 for a bayonet type assembly in recesses 54 formed in the supporting member 13 . | A system for dispensing a fluid product packaged in a bottle ( 1 ), may include a withdrawing member ( 2 ); a band ( 6 ) secured to the bottle ( 1 ) having two upper arms ( 7 ) arranged either side of the nozzle ( 3 ) of the member ( 2 ) which is equipped with two external lugs ( 9 ), said arms each having an interior lug ( 10 ) positioned in the axial continuation of an external lug ( 9 ) to form a housing between them; a support ( 13 ) having a dispensing orifice ( 14 ), the arms ( 7 ) being mounted with the ability to effect a translational movement in said support; a push-button ( 17 ) which is mounted with the ability to effect a radial translational movement in relation to the support ( 13 ), said push-button having two tabs ( 20 ) each having an upper bearing surface ( 20 a ) bearing against an inner lug ( 10 ) an a lower bearing surface ( 20 b ) bearing against an outer lug ( 9 ), said bearing surfaces diverging radially so that depressing the push-button ( 14 ) causes the lugs ( 9, 10 ) to part, thus actuating the withdrawing member ( 2 ) by a depressing of the nozzle ( 3 ) and a raising of the bottle ( 1 ). | 0 |
CROSS REFERENCE
The invention described and claimed hereinbelow is also described in German Patent Applications DE 10 2005 015 139.6 filed on Mar. 31, 2005 and DE 10 2005 035 411.4 filed on Jul. 28, 2005. This German Patent Application provides the basis for a claim of priority of invention under 35 U.S.C. 119(a)-(d).
BACKGROUND OF THE INVENTION
The present invention relates to an electric machine with a tool-poled electric winding.
U.S. Reissue 27,893 disclosed an armature winding in an electric machine in which two coils are situated approximately in geometrically parallel fashion on a laminated armature core. Such an arrangement of the two coils is produced with a winding machine on which two coils can be wound at the same time by means of two flyers. These virtually parallel coils, however, are supplied with current independently of each other so that when the coils are supplied with current during operation, radial force components are exerted on the armature, which generate undesirable motor noise.
SUMMARY OF THE INVENTION
The two-poled electric machine according to the invention and its manufacturing method, with the defining characteristics of the independent claims, have the advantage that the simultaneous commutation of the two symmetrically situated coil sections compensates for the radial force components of the two coil sections when they are supplied with current. Such a symmetrical arrangement of the two coil sections in relation to the rotation axis makes it possible with a simultaneous flow of current through the coil sections, to achieve a smoother motor operation, which significantly reduces the motor noise.
Advantageous modifications and improvements of the defining characteristics disclosed in claim 1 ensue from the defining characteristics disclosed in the dependent claims. The interfering radial force components can be compensated for with particular ease because the two coil sections are situated approximately parallel to each other geometrically, are spaced the same distance apart from the rotation axis, and have the same number of windings.
If the two coils sections are wound in the opposite winding direction from each other on the armature core, then when the coil sections are supplied with current, the respective radial force components of the coil sections are situated in precise opposition to each other. This provides optimum compensation for these radial forces.
In a preferred embodiment, the two coil sections are electrically connected in series so that they can be wound one after another in continuous fashion with a single wire.
In this case, the coil sections connected to each other in series have a total of two ends that can each be directly connected to a respective lamination of the commutator—in particular laminations situated adjacent to each other.
In an alternative embodiment, the two coil sections are electrically connected in parallel, which permits the two coil sections to be wound at the same time as each other, for example.
In the parallel-connected coil sections, the respective ends of the first coil section and the two ends of the second coil section are electrically connected to the same two laminations so that the two coil sections can be commutated simultaneously.
The arrangement of the two coil sections symmetrically to each other on the armature core is optimized in such a way that with the simultaneous flow of current through the two coil sections, the radially acting forces are compensated for to the greatest extent possible.
According to the invention, the commutator has an even number of laminations, for example eight or ten laminations; the two brushes, preferably contact the laminations offset from each other by approximately 180°. Each pair of coil sections is connected to a pair of laminations.
In order to assure the most uniform possible flow of current during commutation, the brushes are embodied so that as the commutator rotates, they each overlap two adjacent laminations so as to short circuit them. This makes it possible to significantly reduce brush sparking.
It is advantageous to embody the coil sections in the form of a double winding equipped with two approximately parallel coil wires with a reduced cross section. This makes it possible to achieve a higher space factor of the grooves and therefore to increase the output of the electric motor without increasing production time.
The manufacturing method according to the invention for a two-poled electric machine with two coil sections situated symmetrically to each other can be used to easily manufacture a reduced-noise electric drive motor of the kind used, for example, in adjusting applications in motor vehicles. This does not require any appreciable increase in complexity compared to conventional winding methods, thus making it possible, in a cost-neutral fashion, to achieve a significant increase in the quality of the electric machine by reducing the amount of noise it generates.
Various exemplary embodiments of an electric machine according to the invention are shown in the drawings and will be explained in detail in the description that follows.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a schematic cross section through an electric machine,
FIG. 2 is a schematic representation of the current branches in the coils,
FIG. 3 is a cross section through the armature winding according to the prior part,
FIG. 4 is a schematic armature cross section, with the coil sections connected in series,
FIG. 5 is a schematic armature cross section, with the coil sections connected in parallel,
FIG. 6 is a cross section through an armature winding according to the invention,
FIGS. 7 through 11 show various winding schemes for a commutator with ten laminations,
FIG. 12 is a schematic cross section to illustrate the commutator rotation, and
FIGS. 13 and 14 show winding schemes for a commutator with eight laminations.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 schematically depicts a cross section through an electric machine 10 that is embodied in the form of a two-poled dc motor 12 in the exemplary embodiment. A housing 14 contains a stator 16 , which is equipped with two permanent magnets 18 and cooperates with a rotor 20 that is supported so that it can rotate in the housing 14 . The rotor 20 has a rotor shaft 22 and a laminated armature core 24 on which coils 26 are wound in the form of chords. The armature shaft 22 also supports a commutator 28 that can be electrically commutated via brushes 30 . In the exemplary embodiment, the two brushes 30 are situated offset from each other by approximately 180° and are embodied in such a way that as the commutator 28 rotates in relation to the brushes 30 , at the transition from one commutator lamination 32 to an adjacent commutator lamination 32 , the brushes 30 short circuit the two laminations. The two brushes 30 are labeled with a plus and a minus that symbolize the flow of current and represent the electrical connections of the coils 26 shown in FIGS. 3 and 6 . The commutator 28 has an even number of laminations 32 that are labeled with the reference numerals 0 through 9 (i.e. there are ten of them). The laminations 32 are electrically insulated from one another.
FIG. 2 schematically depicts the flow of current when the brushes 30 overlap the laminations 32 as shown in FIG. 1 . The short circuiting of two commutator laminations 32 generates a current I 1 through a coil 26 , for example under the plus brush 30 , between the two adjacent laminations 32 ( 9 and 0 ). Between the plus brush 30 and the minus brush 30 , there is a current branch I 2 , which in another coil 26 between the laminations 32 ( 0 and 4 ), a current I 3 between two adjacent laminations 32 ( 4 and 5 ) and in turn a current branch I 4 between the minus brush 30 and the plus brush 30 (laminations 5 and 9 ).
FIG. 3 shows the current flow according to FIG. 2 in a schematic cross section through the armature core 24 , with a chorded loop winding according to the prior part. In accordance with the ten laminations 32 of the commutator 28 , the armature core 24 has ten grooves 34 into which a total of ten coils are wound. Each groove 34 is thus provided with two phase windings 29 of different coils 26 . The differences in the brush voltage drop between the plus brush 30 and the minus brush 30 and the asymmetry in the positioning of the brushes 30 due to production tolerances result in unequal current levels in the opposing grooves 34 , not only in I 1 and I 3 , but also in I 2 and I 4 . For example, the current I 1 travels in one chord-like coil 26 ′, whose windings are depicted with the two circuits +I 1 and −I 1 . At the same time, in the short circuit situation depicted in FIG. 2 , the current I 3 flows in the coil 26 ″, depicted with the circuits +I 3 and −I 3 . It is clear in FIG. 3 that in the prior art, the current level is unequal in the respectively opposing grooves 34 in which the currents I 1 and I 3 flow, which inequality exerts radial forces 36 on the rotor 20 .
FIG. 4 is a schematic cross section through an armature core 24 in which a coil 26 is wound according to the invention in the form of two coil sections 27 in different grooves 34 . The two coil sections 27 are situated in virtually parallel planes 38 that are spaced the same distance apart from the armature shaft 22 , i.e. from the rotation axis 23 , and are symmetrical to it (chorded winding). The two coil sections 27 are electrically connected in series with each other so that starting from the first lamination 32 , the current first flows through the first coil section 27 , then through the second coil section 27 , and then to a second lamination 32 . If the brushes 30 supply these two laminations 32 with current, then the respective radial forces 36 of the two symmetrical coil sections 27 compensate for each other. For the sake of clarity, FIG. 4 schematically depicts only two laminations and one pair of coil sections 27 . In the actual layout, several pairs of coil sections 27 are each connected to a respective pair of laminations 32 . The coil 26 shown in FIG. 4 , which is comprised of two coil sections 27 , could, for example, be associated with the current flow I 1 between the laminations 32 ( 9 and 0 ) from FIG. 2 and FIG. 1 .
In the embodiment according to FIG. 5 , the two coil sections 27 are once again situated symmetrically in relation to the rotation axis 23 . The two coil sections 27 are each wound in respective groove pairs 34 , producing a geometrically parallel arrangement of coil sections 27 spaced approximately the same distance apart from the rotation axis 23 . In such chorded windings, the windings 54 do not pass through the rotation axis 23 . But in this embodiment, the two coil sections 27 are electrically connected in parallel so that the respective ends 42 of the first coil section 41 and the two ends 44 of the second coil section 43 are respectively connected to the two laminations 32 ( 9 and 0 ) in the same fashion. With these parallel-connected coil sections 27 , too, a pair of coil sections 27 is commutated simultaneously by the two laminations 32 . According to a preferred embodiment of the invention, the two coil sections 27 in both the series circuit and the parallel circuit are wound in opposite winding directions from each other, i.e. when the armature winding 25 is being wound, after the rotation of the rotor 20 by approx. 180°, the second coil section 27 is wound in the opposite direction in relation to the winding machine.
FIG. 6 is a schematic cross section through the armature core 24 , in which the respective coils 26 are embodied as two coil sections 27 arranged symmetrically to each other, but this time with four phase windings 29 situated in each groove 34 . This becomes particularly clear when one compares the coil arrangement according to the invention in FIG. 6 to the coil arrangement according to the prior art in FIG. 3 . Each coil from FIG. 3 is placed in two symmetrically situated coil sections 27 ′, 27 ″, where with a series connection of the coil sections 27 ′ and 27 ″, the total number of windings 54 of the two coil sections 27 ′, 27 ″ is identical to the number of windings 54 of the coil 26 according to FIG. 3 . But in the present instance, the current load is identical in the opposing grooves 34 in which the currents I 1 and I 3 flow. As a result, the currents +I 3 , −I 1 , +I 2 , −I 4 , of the groove 34 ′ compensate for the currents −I 3 , +I 1 , −I 2 , +I 4 of the opposing groove 34 ″. This largely eliminates interfering radial forces 36 .
With a parallel connection of the coil sections 27 ′ and 27 ″, the total number of windings 54 doubles in relation to that in the series-connected coil sections 27 ; the wire cross sections of the coil wires 48 are correspondingly halved, thus yielding the same current load. This corresponds to a double winding in which the two coil sections 27 are not, however, wound into the same grooves 34 , but are instead wound in the form of two symmetrically situated coil sections 27 spaced the same distance apart from the rotation axis 23 . The winding scheme for this double winding is shown in FIGS. 11 and 14 .
FIGS. 7 through 11 show different variants for a winding with symmetrical coil sections 27 ; the winding scheme in FIG. 7 will be explained by way of example below. At the bottom edge of the drawing, the ten laminations 32 of the commutator are depicted in the form of small boxes; the drawing shows two developed rotations of the commutator 28 . Situated above them, the grooves 34 of the armature core 24 are schematically depicted, likewise in the form of two developed rotations. In the lower half of the drawing, a pair of coil sections 27 is schematically depicted, which corresponds to the second row of the table above. Starting from the lamination 1 (right), the coil wire 48 is first placed in the groove 1 and then in the groove 5 , thus forming a coil section 27 with seven windings 54 (wdg). After the seventh complete winding 54 , the coil wire 48 once again lies in the groove 1 in order to then travel leftward to the groove 6 in order to form the second coil section 27 . Between groove 6 and groove 10 , the second coil section 27 is wound with eight windings; then one more winding is wound onto the first coil section 27 between groove 10 and groove 5 in order for the coil wire 48 to then contact the lamination 2 (left). This results in a symmetrical arrangement of two coil sections 27 , each with the same number of windings 54 . The respective coil sections 27 are wound according to this scheme, row by row according to the table above so that a total of ten pairs of coil sections 27 are situated between two adjacent laminations.
Thus FIGS. 7 through 10 show different variations, each with ten coil section pairs 27 between two respective laminations 32 . The coil wire 48 in these instances has, for example, a wire diameter of 0.5 mm. In FIG. 11 , the coil sections 27 are situated as a double winding in a first and second layer; in this case the wire diameter is 2×0.355 mm, for example.
FIG. 12 schematically depicts the rotation of the commutator 28 in relation to the armature core 24 . In it, a rotation angle 50 is defined that extends from the center of the groove 34 to the center of a slot 52 between two laminations 32 . In the exemplary embodiments according to FIGS. 7 through 11 , this angle 50 of the commutator rotation is approximately 0°. In the exemplary embodiments according to FIGS. 13 and 14 , this angle 50 is 209°, for example.
According to FIGS. 13 and 14 , the commutator 28 has, for example, eight laminations 32 and correspondingly has eight grooves 34 in the armature core 24 .
In FIG. 13 , according to the eight lines of the table at the top, two symmetrical coil sections 27 are each placed eight times between two laminations 32 . The number of the individual windings 54 (wdg) and the coil wire diameter can be adapted to the respective application. In a fashion analogous to FIG. 11 , FIG. 14 once again shows a double winding in which the total number of windings (wdg) of the two coil sections is increased in comparison to FIG. 13 , for which purpose the wire diameter is reduced (for example from 0.425 to 2×0.3 mm).
It should be noted with regard to the exemplary embodiments of the specification shown in all of the figures that there are a multitude of possibilities for combining the individual defining characteristics with one another. It is thus possible, for example, to vary the number of laminations 32 and grooves 34 as well as their concrete layout. Furthermore, the large number of winding schemes demonstrated should not in any way be taken to represent a limitation with regard to the winding of symmetrical coil sections 27 ; there are, instead, various possible transitions from one coil section 27 to the other. The exemplary embodiments according to FIGS. 7 through 14 describe both the concrete layout of the various electrical machines 10 and also their manufacturing method. In particular, the figures demonstrate the method for winding symmetrical coil sections 27 according to the present invention. | The invention relates to an electrical machine ( 10 ), and to a method for producing such an electrical machine, especially for adjusting mobile parts in a motor vehicle. Said machine comprises a rotor ( 20 ) on which a bipolar electrical winding ( 25 ) having a plurality of coils ( 26 ) is arranged. Said coils ( 26 ) are configured to give two symmetrical coil sections ( 27 ) each which are disposed symmetrical to each other relative to the axis of rotation ( 23 ) of the rotor ( 20 ), both coil sections ( 27 ) being simultaneously commutable. | 7 |
FIELD OF THE INVENTION
The present invention relates to a wire carrier, such as a wire carrier used for reinforcement of an elastomeric strip used in sealing such as, for example, for gripping and covering edge flanges surrounding an opening in a vehicle body, and more particularly to a wire carrier which does not stretch during an elastomeric extrusion process and which in turn does not shrink after being final sized, installed, and throughout its life.
BACKGROUND OF THE INVENTION
Wire carriers typically comprise a continuous wire weft formed into a zig-zag formation with substantially parallel limbs interconnected by connecting regions at each end of the limbs onto which weft is knitted, sewn, threaded, or otherwise disposed a plurality of warp threads. These warp threads are typically a synthetic resin or a natural fiber.
Such a wire carrier is widely used, mainly as a reinforcing frame for coated polymeric products, especially extrusion coated products, such as weather seals on motor vehicles. During manufacture of the seals, the carrier is passed through an extruder and is thus subjected to stresses and temperatures which can cause the warp threads to drift laterally, stretch longitudinally and degenerate both physically and chemically. This can result, for example, in breakage of the warps and distortion of the wire carrier which affects the extrusion process and leads to reduced quality and performance of the corresponding seal. In forming and extrusion processes drifting of the warp threads can cause air bubbles and exposure of the wire in the final weather seal. Finally, when the warp threads are thus processed with a tensile stress during extrusion, the resultant product may experience shrinkage after being final sized and installed, which becomes a problem for the end customer. There has long been a need to develop a stable wire carrier for extruded and molded polymeric products which overcomes these problems and some attempts have been made without complete success.
The prior art has shown attempts at solving some of the above-described problems. One attempt to solve the problem of lateral warp shifting formed adjacent zig-zag loops into a propeller or banana shape, but this is difficult to control, and has little effect on preventing lateral warp drifting.
In another attempt to solve the problem of warp drift, Beck et al, EP Application No. 0175818, have suggested a knitted wire carrier with knotted junctions between the warp threads and the wire weft. Both the warp threads and the wire weft comprise polymeric or polymeric coated material and the polymeric material of the warp and the weft must both be melted to form a weld or fusion at the crossover points. This structure suffers from several disadvantages. It is difficult and expensive to provide either a polymer-coated wire weft, or the combination of an uncoated wire weft with a polymeric material which is fed to the knitting machine with the wire. Furthermore, the use of polymeric meltable materials in both the warp and weft increases the cost of the wire carrier. These disadvantages increase the costs enough that it could not be used commercially.
EP 0384613 discloses a knitted wire carrier in which stitched warp threads comprise two threads of polymeric material having different melting points such that when the melting point of the lower melting thread is exceeded the melted thread causes the other thread to be attached to the wire weft. This structure allows single strands of warp thread plied with a meltable filament to be bonded to the wire carrier wherever they are knitted.
Similarly, U.S. Pat. No. 5,416,961 to Vinay discloses a knitted wire carrier comprising at least one meltable filament laid-in into at least two adjacent warp threads, whereby on heating, the melted filament causes the at least two adjacent warp threads to be bonded to the wire and/or to each other for stabilizing the resulting wire carrier against warp drift. While the above constructions address warp drift, they do not address elongation.
The use of various materials for warp threads also does not solve the problem of elongation. That is, even using warp threads made from materials having zero to very low elongation factors does not completely prevent a wire carrier from suffering from elongation and eventual shrinkage. For example, even if fiberglass threads, which have a very low elongation factor, were used as the warp threads in a wire carrier, the knotted junctions of the threads wrapped around the carrier takes away from the ability of the threads to completely prevent elongation. While the short pieces of thread between the knots may be free of elongation during extrusion, the knots themselves are apt to become tighter during extrusion and looser after processing. Thus, tying knots in fiberglass or other threads with very low elongation factors takes away their ability to effectively prevent elongation throughout the wire carrier.
Thus, none of the above described constructions provides an entirely satisfactory structure for a wire carrier having warp threads attached to a wire support for use in a weather seal because none address the issue of shrinkage in the final product resulting from elongation of the warp threads during extrusion.
Thus, there is a need to reduce final product shrinkage by reducing wire carrier elongation during preforming, extrusion, and postforming. There is further a need to reduce the shrink that is realized in weather seals in the short term after extruding, during secondary operations, and after extended time in the field. There is further a need to retain the spacing between generally parallel limbs of a wire weft during extrusion processing for prevention of elongation. There is further a need for a simple, inexpensive elongation prevention mechanism to solve the above needs. There is further a need for such an elongation prevention mechanism which is easy to incorporate into the manufacture of a wire carrier.
SUMMARY OF THE INVENTION
Therefore, it is an object of the present invention to provide a wire carrier with an elongation prevention mechanism which prevents the shrink realized in weather seals after extruding and after extended time in the field.
It is another object of the present invention to provide an elongation prevention mechanism which substantially retains the relative spacing between adjacent limbs in a wire weft
It is another object of the present invention to provide an elongation prevention mechanism which is inexpensive.
It is another object of the present invention to provide a ribbon usable as an elongation prevention mechanism and securable to a wire carrier.
It is a further object of the present invention to provide stiffening elements, such as fiberglass or carbon fiber threads, along the longitudinal axis of the ribbon.
It is a further object of the present invention to secure the ribbon to the wire carrier using warp threads.
It is another object of the present invention to secure the ribbon to the wire carrier using adhesive.
It is another object of the present invention to secure the ribbon to the wire carrier by weaving.
It is yet another object of the present invention to provide methods for manufacturing a wire carrier employing a ribbon elongation prevention mechanism.
Other objects will in part be obvious and in part appear hereinafter.
In a preferred embodiment of the present invention, a wire carrier for use in a weather seal may comprise a wire folded into a zig-zag configuration so as to have a plurality of generally parallel limbs interconnected at alternate ends by connecting regions for carrying polymeric warp threads on the parallel limbs, the wire carrier having a width substantially defined by a length of one of the plurality of generally parallel limbs, a plurality of warp threads, such as polymeric warp threads, knitted, sewn, threaded, or otherwise secured to the wire to encompass the wire within a stitch of each knitted row of warp thread, and at least one ribbon having stiffening elements along its longitudinal axis.
The ribbon(s) is preferably secured to the wire such that the stiffening elements extend substantially perpendicularly to the plurality of generally parallel limbs. The ribbon may be adhesively secured over at least one row of warp threads by providing an adhesive coating on the rear surface of the ribbon to form a tape. Alternatively, the ribbon may be trapped along its longitudinal axis between a securing row of warp thread and the wire. Alternatively, the ribbon may be weaved through the wire weft. The stiffening elements may comprise carbon or fiberglass threads, or other elements with zero to low elongation factor. The stiffening elements may be secured to each other in a weave by a weft thread.
The wire carrier may use a single ribbon positioned in a central location along the plurality of generally parallel limbs. Alternatively, a first ribbon may be positioned between a first set of warp threads and a second ribbon positioned between a second set of warp threads, such that the first ribbon, the second ribbon, the first set of warp threads, and the second set of warp threads are spaced apart along the width of the wire carrier. Alternate configurations are also within the scope of the invention.
In a method for manufacturing a wire carrier as disclosed in the present invention, one may follow the steps of forming a wire into a zig-zag configuration having a plurality of generally parallel limbs interconnected at alternate ends by connecting regions for carrying warp threads on the parallel limbs, feeding a plurality of warp threads to the wire, securing the warp threads on the wire, such as by knitting, sewing, or threading, to encompass the wire within a stitch of each row of warp thread, and attaching at least one ribbon having stiffening elements along its longitudinal axis to the wire carrier such that the at least one ribbon is secured substantially perpendicularly to the plurality of generally parallel limbs. The step of attaching the ribbon(s) may comprise feeding the ribbon(s) to the wire and trapping the at least one ribbon along its longitudinal axis between at least one row of warp thread and the wire or weaving the ribbon(s) through the parallel limbs of the wire. Alternatively, one may adhesively secure the ribbon(s) over at least one row of warp thread, and may then pass the wire carrier through pinch rollers to increase adhesion.
The foregoing and other features and advantages of the invention will be more readily understood and fully appreciated from the following detailed description, taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a top view of a prior art wire carrier having rows of warp threads.
FIG. 2 shows a top view of an improved wire carrier having an elongation prevention mechanism in a preferred embodiment of the present invention.
FIG. 3 shows a top view of an improved wire carrier having an elongation prevention mechanism in another preferred embodiment of the present invention.
FIG. 4 shows a top view of an improved wire carrier having an elongation prevention mechanism in yet another preferred embodiment of the present invention.
FIG. 5 shows a top view of an improved wire carrier
FIG. 6 shows a top view of a ribbon for use as an elongation prevention mechanism in the present invention.
FIG. 7 shows a detail top view of a ribbon for use as an elongation prevention mechanism in one embodiment of the present invention.
FIG. 8 shows a side view of a ribbon for use as an elongation prevention mechanism in the preferred embodiment of the present invention depicted in FIG. 4.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
A wire carrier in accordance with this invention is shown in the drawing FIG. 1. The carrier 2 includes a length of wire support 4, preferably uncoated, formed into a weft having a zig-zag configuration of generally parallel limbs 6, 8, 10 interconnected at alternate ends by connecting regions 12, 14 which define the edges of the carrier. The zig-zag configuration of the wire can be extended to any desired length for carrying the warp threads. Preferably the wire 4 is an uncoated length of about 30 mil (0.76 mm) diameter steel wire, for example carbon steel or 301 stainless steel wire. The wire may be coated with a non-meltable protective layer, for example, with a rust protective coating.
A plurality of warp threads or yarns 16, 18, 20, 22, for example, are secured to the wire support 4, such as by knitting, sewing, or threading, to reinforce the wire support 4 and form a wire carrier 2. The warp threads encompass the wire 4 within a stitch of each row of warp thread. The warp threads are secured to the wire 4, preferably with chain stitching to minimize warp drift and the warp threads are pretensioned, for example, to 0.5-2 pounds per warp end, preferably one pound.
The warp threads preferably comprise a polymeric material.
By polymeric we mean a polymer based on organic or organosilicone chemistry. The polymer may be a synthetic resin or a natural fiber such as cotton. Synthetic resins are more durable and resistant to, although not free from, the stresses incurred during fabrication of the coated product, for example during extrusion, and are preferred. Suitable polymeric materials include, for example polyesters, polypropylenes and nylons. The polyester, polyethylene terephthalate, is particularly suitable. Preferably, the warp threads have a size of about 1000 denier.
If the spacing between the generally parallel limbs 6, 8, 10 increases due to elongation of the wire carrier during extrusion, then there will be a significant risk of shrinkage, to at least some degree, in the final product because when the limbs spread out the warp threads 16, 18, 20, and 22 are processed with a tensile stress. After the product is final sized, installed, and throughout the product's life, as the tensile stress in the warp threads decreases, the entire product will experience shrinkage. Therefore, while elongation may not significantly affect the manufacturing of a wire carrier, the customer receiving the final product may not be satisfied with the product due to shrinkage. The present invention overcomes this shrinkage problem by preventing the spacing between generally parallel limbs 6, 8, 10 from increasing during extrusion processes.
A ribbon or tape 30 containing a stiffening element, such as, but not limited to fiberglass or carbon threads, along its longitudinal axis, is introduced and becomes a part of the wire carrier, as shown in FIGS. 2-5. In FIG. 2, a relatively small wire carrier 28 with warp threads 16 and 22 adjacent connecting regions 12 and 14 is shown with ribbon 30 introduced along a middle portion of the wire carrier 28. The ribbon 30 is secured to the wire carrier 28 by warp threads 40 which are threaded on the wire 4 in a manner corresponding to the method of attaching the warp threads 16 and 22, such as by chain stitching, although alternate methods of sewing, stitching, or knitting are within the scope of this invention. The ribbon 30 becomes trapped between the threads 40 and the wire 4. As shown in FIG. 3, a larger wire carrier 46 is shown with warp threads 16, 18, 20, and 22 as in FIG. 1. The improved carrier 46 is provided with a reinforcing ribbon 30 positioned between warp threads 16 and warp threads 18, and a reinforcing ribbon 30 positioned between warp threads 20 and warp threads 22. Thus, the larger wire carrier 46 is provided with elongation prevention mechanisms evenly distributed about the width of the carrier 46. Although two specific embodiments of wire carriers and placement of reinforcing ribbons 30 are shown, it should be understood that alternate arrangements of warp threads and ribbons are within the scope of the present invention. For example, any or all of warp threads 16, 18, 20, and 22 could be used to secure ribbon 30 to the wire 4.
Turning now to FIG. 4, an alternate preferred embodiment of the present invention is shown. In this embodiment, the wire carrier 48 is shown with warp threads 16, 18, 20, and 22 as in FIG. 1, with warp threads 18 and 20 shown in phantom. Reinforcing tape 50 is positioned over warp threads 18 and 20 and between warp threads 16 and 22. Reinforcing tape 50 may be adhesively secured to the warp threads 18 and 20. Alternatively, a ribbon 30 (not shown) could be adhered to the wire weft 4 such as by a latex covering. Although not shown, warp threads 16 and 22 could also be covered by separate reinforcing tapes 50. Also, any arrangement of warp threads used and subsequently covered by tape 50 would be within the scope of this invention. The reinforcing tape 50 prevents the wire carrier 48 from elongating during processing and prior art wire carriers can be manufactured by simply adding a taping step as opposed to changing any preexisting manufacturing steps.
Yet another alternate preferred embodiment of the present invention is shown in FIG. 5. In this embodiment, the wire carrier 60 is shown with warp threads 16, 18, 20, and 22 as in FIG. 1. Ribbons 30 are shown placed between warp threads 16 and 18 and between warp threads 20 and 22, similar to the embodiment shown in FIG. 3. In this embodiment, however, the ribbons 30 are weaved within the wire weft 4 such that the ribbons 30 pass over and under alternating generally parallel limbs 6, 8, 10, thus eliminating the need for additional rows of securing warp threads 40.
The above described embodiments are illustrative of some embodiments for incorporating an elongation prevention mechanism into a wire carrier. Other embodiments not herein described are within the scope of this invention so long as the wire carrier is prevented from elongating during extrusion to prevent subsequent shrinkage in a final product.
As shown in FIG. 6, the ribbon 30 is provided with stiffening elements 32 generally parallel to the longitudinal axis 34 of the ribbon 30. The stiffening elements 32 may comprise fiberglass or carbon threads, but may also comprise any other element with a zero to very low elongation factor. As shown in FIG. 7, where the size of the elements are exaggerated for clarity, the stiffening elements 32 may be held together in a weave by a weft thread 36. The weft thread 36 may also be a fiberglass or carbon thread, or other element with a zero to very low elongation factor, although its composition is irrelevant to the prevention of elongation in the wire carrier. As shown in FIG. 8, the ribbon 30 may be provided with a lower layer of adhesive 52 to form the tape 50 for use in the embodiment of the improved wire carrier depicted in FIG. 4.
Because the stiffening elements 32 in the ribbon or tape 30, 50, are not individually tied or stitched to the wire carrier, they do not suffer from tightening and loosening about the wire carrier as do warp threads. The stiffening elements 32 pass over, or over and under, the wire carrier without looping about the wire carrier, that is, without having any of the stiffening elements 32 cross over themselves such that each stiffening element passes each limb only once.
The ribbon 30 or tape 50, being an integral part of the wire carrier, prevents elongation of the wire carrier during subsequent manufacturing operations. The prevention of this elongation in turn prevents the warp threads from being processed with a tensile stress which after rubber extrusion can cause the part to "shrink" after being final sized, installed and throughout its life.
The ribbon or tape can be applied to all wire carrier products that use any thread or yarns which will have elongation during subsequent processing at extrusion houses. The stiffening element in the ribbon/tape prevents the wire carrier from elongating initially while being processed, and, once encapsulated by rubber or other compounds, will not allow the other threads or yarns to collapse and/or buckle allowing the finished part to retain its original length. Some of the advantages thus resulting from the present invention include a carrier which is provided with increased resistance to elongation, the number of other threads and yarns in the wire carrier is reduced, and there is more precise control of length at the finishing operations.
In a method for forming the wire carrier of the present invention, the wire is fed from a supply drum through the wire guide to form the wire weft of the carrier into a zig-zag configuration on which the warp threads are secured, for example, with chain stitching. A plurality of warp threads is fed to the wire from a beam or a plurality of supply cones, under a tension of from about 0.5-2 pounds per warp end, preferably about 1 pound. In the embodiment using ribbon 30 without adhesive, the ribbon may be fed from a cone and secured by warp threads simultaneously as any other warp threads are disposed onto the wire, or, in the embodiment which weaves the ribbon 30 through the generally parallel limbs, the ribbon 30 may be weaved through the wire weft prior to threading the warp threads . In the embodiment using tape 50, a strip of fiberglass tape may be attached over each group of warp threads or over selective groups of warp threads immediately after threading (i.e., knitting, sewing, or otherwise securing the threads), and before the carrier goes onto the take up. Pinch rollers may be used to increase adhesion. The material may then be sent to a rewind station, as it could be produced defect free. Alternatively, the material could be shipped directly from a knitter which would eliminate blocking totally. To save space and tape, the tape may be installed at the blocker instead of at the knitter. The material would go to blocking for tape installation.
Thus, it is apparent that there has been provided, in accordance with the invention, a wire carrier and a method for making a wire carrier that fully satisfies the objects and advantages set forth above. The wire carrier is produced with ribbon or tape strips having stiffening elements, such as fiberglass threads installed at specific places which remains adhered to the carrier and becomes part of the rubber extrusion. The strength of the stiffening elements prevent stretching of the wire carrier during the extrusion process, which eliminates the memory effect of the warp threads that contributes to shrink back. In addition, the fiberglass staples act as a deterrent to the shrink realized from a decrease in the tensile stress of the warp threads, that results during the curing of the rubber and the environmental effect. While the invention has been described in conjunction with specific embodiments thereof, it is evident that many alternatives, modifications, and variations will be apparent to those skilled in the art in light of the foregoing description. For example, although the ribbon 30 is shown with only one securing warp thread 40, a wider ribbon 30 could be provided with two or more warp threads 40 securing the ribbon to a wire carrier. In addition, although specific embodiments of improved wire carriers are shown in FIGS. 2-5, alternate arrangements such as two ribbons 30 positioned between the warp threads 16 and 22 of FIG. 2, or a ribbon 30 positioned between warp threads 18 and 20 of FIG. 3, or a wide tape 50 covering all warp threads in FIG. 4, or various weave formations in FIG. 5 are all within the scope of the present invention. Accordingly, the present invention is intended to embrace all such alternatives, modifications, and variations as fall within the spirit and broad scope of the appended claims. | A wire carrier for use in the manufacture of weather seals is disclosed comprising a wire folded into a zig-zag configuration and having a plurality of generally parallel limbs for carrying a plurality of polymeric warp threads secured to the wire and at least one ribbon, having stiffening elements along its longitudinal axis, secured to the wire carrier such that the ribbon(s) runs substantially perpendicularly to the limbs of the wire. The ribbon may be secured to the wire by adhesive, by weaving, or by at least one row of warp thread. The resulting wire carrier is prevented from elongating during extrusion and thus a resulting product does not experience shrinkage. Methods for manufacturing the carrier are also disclosed. | 3 |
BACKGROUND
[0001] Modern oil field operators demand access to a great quantity of information regarding the parameters and conditions encountered downhole. Such information typically includes characteristics of the earth formations traversed by the borehole and data relating to the size and configuration of the borehole itself. The collection of information relating to conditions downhole, which commonly is referred to as “logging,” can be performed by several methods including wireline logging, “logging while drilling” (LWD), and tubing-conveyed logging.
[0002] In wireline logging, a probe or “sonde” is lowered into the borehole after some or all of the well has been drilled. The sonde hangs at the end of a long cable or “wireline” that provides mechanical support to the sonde and also provides an electrical connection between the sonde and electrical equipment located at the surface of the well. In accordance with existing logging techniques, various parameters of the earth's formations are measured and correlated with the position of the sonde in the borehole as the sonde is pulled uphole.
[0003] In LWD, the drilling assembly includes sensing instruments that measure various parameters as the formation is being penetrated, thereby enabling measurements of the formation while it is less affected by fluid invasion. While LWD measurements are desirable, drilling operations create an environment that is generally hostile to electronic instrumentation, telemetry, and sensor operations.
[0004] Tubing-conveyed logging, like wireline logging, is performed in an existing borehole. Unlike wireline logging, tubing-conveyed logging enables a logging tool to travel where a wireline-suspended tool cannot, e.g., in a horizontal or ascending borehole. Tubing-conveyed logging, tools typically suffer from restricted communications bandwidths, meaning that acquired data is generally stored in memory and downloaded from the tool when the tool returns to the surface.
[0005] In these and other logging environments, measured parameters are usually recorded and displayed in the form of a log, i.e., a two-dimensional graph showing the measured parameter as a function of tool position or depth. In addition to making parameter measurements as a function of depth, some logging tools also provide parameter measurements as a function of azimuth, Such tool measurements have often been displayed as two-dimensional images of the borehole wall, with one dimension representing tool position or depth, the other dimension representing azimuthal orientation, and the pixel intensity or color representing the parameter value.
[0006] Once a borehole has been drilled, operators often wish to perform downhole formation testing before finalizing a completion and production strategy. Fluid sampling tools enable operators to draw fluid (i.e., gas or liquid) samples directly from the borehole wall and measure contamination levels, compositions, and phases, usually based on the properties (e.g., optical properties, electrical properties, density, NMR, and PVT properties) of the materials drawn into the sample chamber. Existing downhole fluid analysis tools may have a limited reliability due to, e.g., insufficient instrumentation to perform in-situ analysis, or conversely, too many moving parts.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] Accordingly, there are disclosed in the drawings and detailed description specific embodiments of methods, systems, and downhole tools that employ spatial heterodyne integrated computational element (“SH-ICE”) spectrometers. In the drawings:
[0008] FIG. 1 shows an illustrative environment for logging while drilling (“LWD”).
[0009] FIG. 2 shows an illustrative environment for wireline logging.
[0010] FIG. 3 shows an illustrative environment for tubing-conveyed logging.
[0011] FIG. 4 shows an illustrative formation fluid sampling tool.
[0012] FIGS. 5A-5C show illustrative embodiments of a SH-ICE spectrometer based fluid analyzer.
[0013] FIGS. 6A-6D illustrate a wavelength-to-spatial fringe relationship.
[0014] FIG. 6E shows an illustrative combined spatial fringe intensity.
[0015] FIG. 6F shows an illustrative spatial fringe image.
[0016] FIG. 7A shows an illustrative multiplex integrated computational element (“ICE”).
[0017] FIG. 7B shows an illustrative spatially-dependent ICE.
[0018] FIG. 7C shows an illustrative multiplex spatially-dependent ICE.
[0019] FIG. 8 is a flowchart of an illustrative downhole fluid analysis method.
[0020] It should be understood, however, that the specific embodiments given in the drawings and detailed description do not limit the disclosure. On the contrary, they provide the foundation for one of ordinary skill to discern the alternative forms, equivalents, and modifications that are encompassed in the scope of the appended claims.
DETAILED DESCRIPTION
[0021] Various systems and methods for performing optical analysis with combined spatial-heterodyne (“SH”) integrated computational element (“ICE”), or “SH-ICE” spectrometer. Light from a light source encounters a material to be analyzed, such as a formation fluid sample, a borehole fluid sample, a core sample, or a portion of the borehole wall. The encounter can take various forms, including transmission (attenuation) through the sample, reflection from the sample, attenuated total reflectance (evanescent wave), scattering from the sample, and fluorescence excitation. In any event, the spectral characteristics of the material are imprinted on the light beam and can be readily analyzed with the spectrometer to obtain a measure of characteristics of the substance such as concentrations of selected components. The disclosed spectrometer is believed to be capable of laboratory-quality measurements in a wide range of contexts including a hostile downhole environment.
Context
[0022] The disclosed systems and methods are best understood in the context of the larger systems in which they might be employed. FIG. 1 shows an illustrative logging while drilling (LWD) environment. A drilling platform 2 supports a derrick 4 having a traveling block 6 for raising and lowering a drill string 8 . A kelly 10 supports the drill string 8 as it is lowered through a rotary table 12 . A drill bit 14 is driven by a downhole motor and/or rotation of the drill string 8 . As bit 14 rotates, it creates a borehole 16 that passes through various formations 18 . A pump 20 circulates drilling fluid through a feed pipe 22 to kelly 10 , downhole through the interior of drill string 8 , through orifices in drill bit 14 , back to the surface via the annulus around drill string 8 , and into a retention pit 24 . The drilling fluid transports cuttings from the borehole 16 into the pit 24 and aids in maintaining the integrity of the borehole.
[0023] A LWD tool 26 is integrated into the bottom-hole assembly near the bit 14 . As the bit extends the borehole 16 through the formations 18 , logging tool 26 collects measurements relating to various formation properties as well as the tool orientation and. various other drilling conditions. The logging tool 26 may take the form of a drill collar, i.e., a thick-walled tubular that provides weight and rigidity to aid the drilling process. As explained further below, tool assembly 26 includes a optical fluid analysis tool that monitors wellbore fluid properties. A telemetry sub 28 may be included to transfer measurement data to a surface receiver 30 and to receive commands from the surface. In some embodiments, the telemetry sub 28 does not communicate with the surface, but rather stores logging data for later retrieval at the surface when the logging assembly is recovered.
[0024] At various times during the drilling process, the drill string 8 may be removed from the borehole as shown in FIG. 2 . Once the drill string has been removed, logging, operations can be conducted using a wireline logging tool 34 , i.e., a sensing instrument sonde suspended by a cable 42 having conductors for transporting power to the tool and telemetry from the tool to the surface. A wireline logging tool 34 may have pads and/or centralizing springs to maintain the tool near the axis of the borehole as the tool 34 is pulled uphole. As explained further below, tool 34 can include a formation fluid sampler that extends a probe against a borehole wall to draw fluids into a sample analysis chamber, A surface logging facility 44 collects measurements from the logging tool 34 , and includes a computer system 45 for processing and storing the measurements gathered by the logging tool.
[0025] An alternative logging technique is logging with coil tubing. FIG. 3 shows an illustrative coil tubing-conveyed logging system in which coil tubing 54 is pulled from a spool 52 by a tubing injector 56 and injected into a well through a packer 58 and a blowout preventer 60 into the well 62 . (It is also possible to perform drilling in this manner by driving a drill bit with a downhole motor.) In the well, a supervisory sub 64 and one or more logging tools 65 are coupled to the coil tubing 54 and optionally configured to communicate to a surface computer system 66 via information conduits or other telemetry channels. An uphole interface 67 may be provided to exchange communications with the supervisory sub and receive data to be conveyed to the surface computer system 66 .
[0026] Surface computer system 66 is configured to communicate with supervisory sub 64 during the logging process or alternatively configured to download data from the supervisory sub after the tool assembly is retrieved. Surface computer system 66 is preferably configured by software (shown in FIG. 3 in the form of removable information storage media 72 ) to process the logging tool measurements (including the fluid component measurements described further below). System 66 includes a display device 68 and a user-input device 70 to enable a human operator to interact with the system software 72 .
[0027] In each of the foregoing logging environments, the logging tool assemblies preferably include a navigational sensor package that includes directional sensors for determining the inclination angle, the horizontal angle, and the rotational angle (a.k.a. “tool face angle”) of the bottom hole assembly. As is commonly defined in the art, the inclination angle is the deviation from vertically downward, the horizontal angle is the angle in a horizontal plane from true North, and the tool face angle is the orientation (rotational about the tool axis) angle from the high side of the wellbore. In accordance with known techniques, wellbore directional measurements can be made as follows: a three axis accelerometer measures the earth's gravitational field vector relative to the tool axis and a point on the circumference of the tool called the “tool face scribe line”. (The tool face scribe line is typically drawn on the tool surface as a line parallel to the tool axis.) From this measurement, the inclination and tool face angle of the logging assembly can be determined. Additionally, a three axis magnetometer measures the earth's magnetic field vector in a similar manner. From the combined magnetometer and accelerometer data, the horizontal angle of the logging assembly can be determined.
[0028] FIG. 4 shows an illustrative formation fluid sampler tool 80 . Tool 80 can be a drill collar, a coil tubing joint, or a drilling tubular, but most commonly it is expected to be part of a wireline sonde. Tool 80 extends a probe 82 and a foot 84 to contact the borehole wall 17 , typically driving them outward from the tool body using hydraulic pressure. The probe 82 and foot 84 cooperate to seat the probe 82 firmly against the borehole wall 17 and establish a seal that keeps borehole fluids from being drawn into the tool 80 . To improve the seal, the wall-contacting face of the probe 82 includes an elastomeric material 85 that conforms to the borehole wall 17 . A pump 86 draws down the pressure, prompting fluid to flow from the formation through a probe channel 88 , a sample chamber 90 in fluid analyzer 92 , and a sample collection chamber 94 . The pump 86 exhausts fluid into the borehole 16 through a port 96 and continues pumping until a sampling process is completed. Typically, the sampling process continues until the tool 80 determines that the sample collection chamber 94 is full and any contaminants have been exhausted. Thereafter the sample collection chamber 94 is sealed and the probe 82 and foot 84 are retracted. If desired, the tool 80 can repeat the process at different positions within the borehole 16 . Sample collection chamber 94 may be one of many such sample collection chambers in a cassette mechanism 98 , enabling the tool 80 to return many fluid samples to the surface.
Spatial-Heterodyne Integrated Computational Element Spectrometer
[0029] FIGS. 5A-5C show illustrative embodiments of a SH-ICE spectrometer based fluid analyzer. In FIG. 5A , a light source 502 shines light through an inlet window 504 into a sample (shown here as fluid flow stream 506 ). The light source 502 can be either broadband or narrowband. For the purposes of this disclosure, the term “broadband” is used to distinguish from narrowband sources that provide only isolated peaks in their spectrum. The broadband sources contemplated for use downhole have continuous spectrums in the range of 200-400 nm (for UV absorption and fluorescence spectroscopy), 1500-2300 nm (for special purpose spectroscopy, e.g. GOR (gas to oil ratio) determination), and 400-6000 nm (for general purpose VIS-IR spectroscopy). These examples are merely illustrative and not limiting. One readily available source suitable for this purpose is a tungsten-halogen incandescent source with a quartz envelope, generating light across the 300-3000 nm range. Arc lamps, broadband fluorescent sources, broadband quantum light sources, or a combination of a number of relatively narrowband light sources (such as LEDs) may also be suitable light sources. Suitable narrowband light sources are lasers and single wavelength LEDs. Such narrowband light sources may be used for single wavelength excitation spectroscopy (e.g. Raman and Fluorescence).
[0030] The illustrated sample is a fluid flow stream 506 sandwiched between the inlet window 504 and an outlet window 508 . Windows 504 and 50 $ are made from a transparent material (e.g., quartz, diamond, sapphire, zinc selenide) so that the main effect on the spectrum of the light is produced by attenuation as the light passes through the fluid flow stream 506 (i.e., transmission spectroscopy). Other spectrometer configurations may cause the light to interact with the sample (which, in some tool configurations, may be a surface of a solid) via reflection, diffuse reflection, attenuated total reflectance, scattering, or fluorescence. Conversely, some spectrometer embodiments cause the light to pass multiple times through the sample to increase the transmission-induced attenuation.
[0031] The light from the sample chamber may captured by a collimation element such as a mirror or lens 510 . Spectrometer embodiments employing a narrowband source would typically include a notch filter 511 to block the central frequency emitted by the light source 502 to prevent the intensity at this wavelength from overwhelming the measurements at nearby frequencies. The notch filter 511 can be positioned anywhere on the optical path after the sample (e.g., fluid flow stream 506 ).
[0032] One or more apertures 512 may be positioned at various points along the optical path to define the light into a beam and limit the effects of the beam periphery. A dispersive two-beam interferometer 514 employs a beam splitter 516 to split the incoming light beam into two beams that travel along first and second optical paths before being recombined by the beam splitter 516 into an outgoing beam. (A 50/50 splitter is preferred, but not required.)
[0033] Light traveling along the first path interacts with a diffraction grating 518 or other dispersive element that reflects the light at an angle that is dependent on its wavelength. In other words, the beam that returns to the splitter has the spectral components propagating with wavelength-dependent wavefront angles. Similarly, the light traveling along the second path interacts with a second diffraction grating 520 or other dispersive element that produces a return beam with spectral components propagating with wavelength-dependent wavefronts angles. The dispersive elements 518 , 520 are positioned to provide the opposite wavefront angles. As the outgoing beam reaches a detector 530 , the difference in propagation angles produces a set of interference fringes. As explained below with reference to FIGS. 6A-6E (taken from Roesler, U.S. Pat. No. 5,059,027, “Spatial Heterodyne Spectrometer and Method”), the fringes vary based on the wavefront angle.
[0034] For a baseline or reference wavelength λ 0 , the wavefront angles in both beams are aligned, producing no fringes as indicated in FIG. 6A . Graph 602 shows that the intensity as a function of position on a detector (e.g., detector 530 in FIG. 5A ) is constant at this wavelength. As the wavelength increases, the wavefront angles of the two beams become increasingly different. FIG. 6B shows the wavefronts at an angle that produces one fringe on the detector (the intensity variation in graph 604 results when the path difference between the wavefronts varies from −λ/2 on one edge of the detector to +λ/2 on the other edge). FIG. 6C shows the wavefronts at an angle that produces two fringes on the detector (the intensity variation in graph 606 results when the phase difference between the wavefronts varies from −λ to +λ). As indicated in FIG. 6D , each increment of the wavelength by a value δλ adds one fringe across the width of the detector. (Graph 608 shows n fringes across the width of the detector.)
[0035] FIGS. 6A-6D illustrate examples of what occurs when only a single wavelength is present. When multiple wavelengths are present, the intensity vs. position relationship becomes more complex, as indicated by graph 610 in FIG. 6E . Nevertheless, a spatial Fourier transform can separate out the contributions from the individual wavelengths.
[0036] The actual image cast by the outgoing beam on the detector is two dimensional. FIG. 6F (excerpted from a figure in N. Gromer et al., “Raman spectroscopy using a spatial heterodyne spectrometer: proof of concept”, Appl. Spectroscopy v65, n8, 2011) shows an illustrative two dimensional image 612 . Along the width of the detector (i.e., in the x-dimension), the image demonstrates a complex fringe dependence, whereas along the height of the detector (i.e., in the y-dimension) the intensity is relatively constant. The signal-to-noise ratio may be improved by summing or averaging the columns of the image together before analyzing the fringe structure.
[0037] Returning to FIG. 5A , the foregoing discussion neglects the presence of element 522 , which as explained in greater detail below, is an integrated computation element (ICE) that modifies the outgoing beam image before it strikes detector 530 . The ICE 522 is included to exploit the observation that, in addition to spatial intensity variation, the image also contains wavelength-dependent intensity (“color”) variation, enabling further processing to be done on the image before it is captured by the detector 530 .
[0038] The ICE 522 operates to weight the various spectral components of the outgoing light beam by corresponding amounts, the weighting template being chosen based on what fluid properties are being measured. Many ICE implementations are known and potentially suitable, including a transparent substrate carrying a multilayered stack of materials having contrasting refractive indices, e.g., silicon and silica, niobium and niobia, germanium and germania, MgF and SiO. Suitable substrates may include BK-7 optical glass, quartz, sapphire, silicon, germanium, zinc selenide, zinc sulfide, various polymers (e.g., polycarbonates, polymethylmethacrylate, polyvinylchloride), diamond, ceramics, and the like. A transparent protective layer may further be provided over the layers with contrasting refractive indices. The relative weightings of different wavelengths are achieved through a judicious selection of the number, arrangement, and thicknesses of the layers to provide various degrees of optical interference at selected transmitted (or reflected) wavelengths. Other illustrative ICE implementations achieve the wavelength-dependent weightings by suitably varying their transmissivity, reflectivity, absorptivity, dispersivity, and/or scattering properties. Such implementations may employ engineered materials, holographic optical elements, gratings, acousto-optic elements, magneto-optic elements, electro-optic elements, light pipes, and digital light processors (DLPs) or other types of micro-electronic mechanical (MEMS) based light manipulation devices.
[0039] FIG. 7A shows an illustrative ICE 702 of the multi-layered contrasting-refractive index variety. The illustrated ICE 702 is a multiplex device having different multi-layered structures over different image regions 704 , but it is also contemplated that there may be only a single region 704 over the entire substrate surface. The regions 704 are continuous across the width of the device. Hereafter this type of region is described as “row-oriented”. There is no horizontal spatial dependence to the ICE, meaning that, when employed as ICE 522 in FIG. 5A , each of the image fringes is processed based solely on their wavelengths. Nevertheless, the fidelity of the fringe measurement is increased by the suppression of irrelevant wavelength intensities (and hence the spatial fringes irrelevant to the fluid property measurement). Note that this ICE embodiment can be positioned nearly anywhere in the optical path.
[0040] The use of different ICE structures in corresponding row-oriented regions enables different ICE templates to be applied simultaneously. As the number of regions increases, however, the size of each region decreases correspondingly, reducing the total light intensity associated with each measurement. In some embodiments, this loss may be compensated by lengthening the measurement time.
[0041] When the image is captured by a detector 530 ( FIG. 5A ) such as a ICCD (intensified charge coupled device), it is digitized and suitable for digital signal processing. (Other image capture detectors would also be suitable.) As previously mentioned, the processing may include combining measurements from different rows (albeit, different rows within the same region 704 ) to increase the signal to noise ratio, and may further include a spatial Fourier transform to derive the spectral content of the ICE-filtered outgoing beam. Such processing can be done using a software or firmware programmed general purpose processor, or an application specific integrated circuit. Fourier transform processing of the weighed or unweighted spatial pattern would allow for a system that uses SH-ICE to gather spectral data in-situ for calibration or re-calibration.
[0042] In most cases, however, it is expected that a Fourier transform would not be required, but rather the information in each row could be combined (averaged or summed) together to obtain a single value representative of the ICE-specific measurement (e.g., an analyte concentration). Such a measurement can be performed using software or hardware (e.g., an appropriately wired detector) or, as indicated in FIG. 5B , a mirror or lens 524 that focuses the information from each row onto a row-associated point, yielding a one dimensional line. An array of photodetectors 540 may be provided along the line to enable each photodetector 540 acquire a row-associated measurement. Because the imaging array is now only one-dimensional, it can be further simplified to, e.g., a single photodetector 540 and a scanning mirror. The photodetector 540 can take the form of a photodiode, a thermal detector (including thermopiles and pyroelectric detectors), a Golay cell, or a photoconductive element. Cooling can be employed to improve the signal-to-noise ratio of the photodetector 540 .
[0043] Whether the recombining of spatial fringe information is done optically ( FIG. 5B ) or electronically ( FIG. 5A , after image capture by detector 530 ), signal to noise ratio may be improved by combining the measurements associated with all of the rows in a given region 704 .
[0044] In FIGS. 5A and 5B , ICE 522 operates on the transmitted light. The systems can be readily modified to employ the reflected light, as indicated in FIG. 5C , ICE 526 has a wavelength-dependent reflectivity to provide the desired spectral weighting on the fringes that reach detector 530 . Still other system embodiments measure both the transmitted and reflected light to achieve even higher performance, However, a similar performance is achievable with a multiplex ICE 702 having a regions 704 with complementary ICE templates, or by employing at least one ‘reference’ region that is weighted to a constant value (e.g. neutral density) or left as an unweighted (clear) region.
[0045] FIG. 7B shows an alternative ICE 712 that employs a spatial dependence to provide the desired spectral weighting. It employs regions that are continuous across the height of the device, i.e., along the y-axis. Hereafter, this type of region is described as “column-oriented”. Because the spatial dependence corresponds to selected fringes, the wavelength selectivity of the regions can be relaxed. Indeed, some contemplated embodiments employ a mask that equally attenuates all wavelengths in that region of the beam. However, it is believed that the best efficiency will be achieved when at least some wavelength selectivity is combined with at least some spatial dependence, and the highest degree of performance should be achievable when the both the geometry and wavelength selectivity are carefully tailored to the desired measurement.
[0046] FIG. 7C shows an illustrative multiplex ICE 722 in which each row-oriented region 724 employs a spatially-dependent ICE structure. As before, the use of multiplexing enables multiple simultaneous measurements, though it does so by corresponding reducing the light intensity available for each measurement.
[0047] An alternative to a multiplex ICE is the use of multiple ICEs that can be sequentially positioned in the light path, e.g., with the use of a rotating filter wheel. As yet another alternative, the ICE can be dynamically changed, e.g., with a programmable acousto-optic ICE (for changeable wavelength dependence) or a programmable electro-optic ICE (for changeable spatial dependence). Dynamically changeable ICEs may use individually controllable pixels of a liquid crystal tunable filter or an acousto-optical tunable filter. Other programmable ICEs include but are not limited to DLP or other types of MEMS based devices.
[0048] FIG. 8 is a flowchart of an illustrative downhole fluid analysis method. It includes operations represented by blocks shown and described in sequential order, but this sequence is solely for explanatory purposes. In practice, the operations may be performed concurrently or, if sequential, may be performed in a different order or asynchronously.
[0049] In block 802 , the driller positions the fluid analysis tool downhole, e.g., in a wireline sonde or a LWD collar. In block 804 , fluid (e.g., from the formation) is drawn into a sample cell. In block 806 , the light source is energized and calibrated. In some embodiments, the calibration is performed by measuring light received from the source via a path that bypasses the fluid sample. A measurement correction may be derived from this measurement. In addition, or alternatively, a feedback signal may be derived from a measurement based on the output from the light source and used to adjust the light intensity applied to the fluid sample.
[0050] In block 808 , the tool illuminates the fluid sample with light from the source and analyzes the transmitted, reflected, or scattered light using a SH-ICE spectrometer. As discussed previously, the spectrometer obtains measurements indicative of fluid properties such as analyte concentrations. In block 810 , these measurements are processed, either by the tool itself or by a surface facility, to derive the fluid properties. Illustrative properties include amount and type of hydrocarbons (e.g., fractions of saturated, aromatics, resins, and asphaltenes), amount and type of gas phase (e.g., CO 2 , H 2 S, etc.), amount and type of liquid phase (e.g., water cut), PVT properties (including bubble point, gas-to-oil ratio, density variation with temperature), concentrations of compounds such as concentration of treatment fluid, and amount of contamination (e.g., drilling fluid) in formation fluid sample.
[0051] In block 812 , the tool and/or the surface facility communicates and stores the derived information. Contemporaneously, or later, the information is displayed to a user, preferably in the form of a log. In block 814 , the operation of the tool is optionally adjusted in response to the measurement, e.g., by terminating a pumping operation when the contamination level falls below a predetermined threshold.
[0052] The SH-ICE embodiments shown in FIGS. 5A-5C employ a series of discrete optical elements arranged along an optical path, which may further include additional mirrors, lenses, apertures, switches, filters, sources, and detectors. Some contemplated embodiments employ an integrated (“monolithic”) light path component. The integrated component provides reduced sensitivity to temperature changes, pressure changes, vibrations, and shock. A solid block of transparent material (e.g., quartz, sapphire, zinc selenide) is used as the body of the integrated component. Mirror gratings 518 , 520 , beam splitter 516 , also made of the same material, ICE 522 (or ICE 526 ), and focusing element 524 , are fused or otherwise attached to this body without any air gaps to maintain the alignment and spacing of the components over a wide range of temperature, pressure, vibration, and shock conditions.
[0053] Some tool embodiments, rather than being fluid analyzers, analyze a solid that is visible through a window or aperture, such as a core sample or a portion of the borehole wall adjacent to the tool. In such embodiments, the tool tracks the motion of the tool relative to the solid, associating the measurements with time and/or position to construct an image of the sample's surface.
[0054] Various techniques to maximize the quality of the measurements would be known to one of ordinary skill in the oil field industry and can be employed. For example, the tool may be outfitted with a reservoir of a reference fluid for downhole calibration of the system and for compensating for contamination on the windows of the flow cell. Detector cooling or temperature compensation can be used to minimize the effects of temperature drift in the electronics.
[0055] Various other features can be incorporated into the tool. For example, scattered light can be analyzed to determine the size distribution of particles entrained in a fluid flow. An ultraviolet light source can be included to induce fluorescence in the material, which fluorescence can be analyzed to aid in determining composition of the sample.
[0056] The spectrometer designs and methods disclosed herein may be used in technologies beyond the oil field including, for example, the food and drug industry, industrial processing applications, mining industries, or any field where it may be advantageous to quickly determine a spectrally-related characteristic of a material. These and other variations, modifications, and equivalents will be apparent to one of ordinary skill upon reviewing this disclosure, it is intended that the following claims be interpreted to embrace all such variations and modifications where applicable. | A spatial heterodyne spectrometer may employ an integrated computational element (ICE) to obtain a measure of one or more fluid properties without requiring any moving parts, making it particularly suitable for use in a downhole environment. One illustrative method embodiment includes: directing light from a light source to illuminate a sample; transforming light from the sample into spatial fringe patterns using a dispersive two-beam interferometer; adjusting a spectral weighting of the spatial fringe patterns using, an integrated computation element (ICE); focusing spectral-weight-adjusted spatial fringe patterns into combined fringe intensities; detecting the combined fringe intensities; and deriving at least one property of the sample. | 6 |
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims the benefit of U.S. Provisional Application Ser. No. 62/408,962, filed Oct. 17, 2016, and also U.S. Provisional Application Ser. No. 62/286,106, filed Jan. 22, 2016, which are both incorporated herein by way of reference in their entirety.
BACKGROUND OF THE INVENTION
[0002] 1. Technical Field
[0003] This invention relates generally to textile sleeves for protecting elongate members, and more particularly to braided textile sleeves.
[0004] 2. Related Art
[0005] Tubular textile sleeves are known for use to provide protection to internally contained elongate members, such as wire harnesses, fluid or gas conveying tubes, or cables, for example. It is further known to braid tubular textile sleeves for protecting elongate members contained therein. Modern vehicle applications for such sleeves are requiring greater protection to the elongate members, such as against increased environmental temperatures and increased resistance to abrasion. These increased demands require the sleeves to pass various test parameters, such as exposure to increased temperatures and exposure to specifically defined abrasion test specifications, such as abrasion tools being passed along both the length of the sleeve and transversely to the length of the sleeve without abrading through the full braided layer of the sleeve or causing any damage to the elongate member contained therein. Known braided sleeve constructions, under some test parameters, are unable to meet the test specifications, and thus, further development is needed. Of course, it is to be appreciated that the resulting sleeves must not only meet the various thermal and abrasion resistant test requirements, but also must be economical in manufacture; have a relatively small envelope and remain flexible to facilitate installation over meandering paths, which tend to be contrary to the ability to form a sleeve that meets increasingly stringent test parameters.
[0006] A braided sleeve constructed in accordance with this invention is able to meet the increasingly demanding temperature and abrasion resistant test parameters discussed above, while also having a relatively small envelope and remaining flexible, while other benefits may become readily recognized by those possessing ordinary skill in the art.
SUMMARY OF THE INVENTION
[0007] A textile sleeve having a seamless, flexible, abrasion resistant tubular wall of braided yarns is provided. The yarns of the wall are braided to withstand elevated temperatures, such as up to about 175° C., and to resist abrasion through the full wall thickness under specified test parameters, while also remaining sufficiently flexible such that the sleeve can be routed about meandering paths including sharp bends without kinking.
[0008] In accordance with another aspect of the invention, a protective textile sleeve is provided having a flexible, tubular wall of braided yarns. At least some of the yarns are provided as a plurality of monofilaments and at least some of the yarns are provided as a plurality of multifilaments. The plurality of multifilaments are braided in a plurality of separate bundles. Each of the bundles includes at least two multifilaments, wherein the flexible, tubular wall has an outer surface density of between about 500-700 g/m 2 .
[0009] In accordance with another aspect of the invention, the multifilaments have a denier of between about 1000-1200 dTex.
[0010] In accordance with another aspect of the invention, the multifilaments have a tenacity between about 60-85 cN/tex.
[0011] In accordance with another aspect of the invention, the multifilaments are polyester.
[0012] In accordance with another aspect of the invention, the monofilaments have a diameter between about 0.35-0.40 mm.
[0013] In accordance with another aspect of the invention, the monofilaments have a tenacity between about 40-55 cN/tex.
[0014] In accordance with another aspect of the invention, the monofilaments have a Young's Modulus of about 3 GPa.
[0015] In accordance with another aspect of the invention, the plurality of multifilaments and the plurality of monofilaments are braided in a respective ratio of about 2:1.
[0016] A protective textile sleeve constructed in accordance with another aspect of the invention has a flexible, tubular wall of braided yarns, with at least some of the yarns being provided as a plurality of monofilaments and at least some of the yarns being provided as a plurality of multifilaments. The plurality of multifilaments are braided as a plurality of separate bundles, with each of the bundles including at least two multifilaments. Further, the monofilaments have a tenacity between about 40-55 cN/tex, thereby being embedded into the multifilaments to lock the multifilaments in an “as braided” location to enhance the abrasion resistance of the sleeve wall.
[0017] A protective textile sleeve constructed in accordance with another aspect of the invention has a flexible, tubular wall of braided yarns, with at least some of the yarns being provided as a plurality of monofilaments and at least some of the yarns being provided as a plurality of multifilaments. The plurality of multifilaments are braided in a plurality of separate bundles, with each of the bundles including at least two multifilaments, wherein the monofilaments have a Young's Modulus of about 3 GPa, thereby being embedded into the multifilaments to lock the multifilaments in an “as braided” location to enhance the abrasion resistance of the sleeve wall.
[0018] In accordance with another aspect of the invention, a method of constructing a protective textile sleeve is provided. The method includes braiding a flexible, tubular wall from a plurality of monofilaments having a tenacity between about 40-55 cN/tex and a plurality of multifilaments having a denier of between about 1000-1200 dTex. The plurality of multifilaments are braided as a plurality of separate bundles, with each of the separate bundles including at least two multifilaments. The method includes embedding the plurality of monofilaments into the plurality of multifilaments during the braiding process to effectively lock the plurality of multifilaments in place.
[0019] In accordance with another aspect of the invention, the method further includes providing the multifilaments having a tenacity between about 60-85 cN/tex.
[0020] In accordance with another aspect of the invention, the method further includes providing the monofilaments having a diameter between about 0.35-0.40 mm.
[0021] In accordance with another aspect of the invention, the method further includes providing the monofilaments having a Young's Modulus of about 3 GPa.
BRIEF DESCRIPTION OF THE DRAWINGS
[0022] These and other aspects, features and advantages of the invention will become readily apparent to those skilled in the art in view of the following detailed description of the presently preferred embodiments and best mode, appended claims, and accompanying drawings, in which:
[0023] FIG. 1 is a schematic perspective view of a braided protective textile sleeve constructed in accordance with one aspect of the invention shown protecting an elongate member extending therethrough;
[0024] FIG. 2 is an enlarged fragmentary plan view of a wall of the sleeve of FIG. 1 ;
[0025] FIG. 3 is a schematic end view illustrating a braid structure of the sleeve of FIG. 1 depicting a ratio of bundled multifilaments and individual monofilaments;
[0026] FIG. 4 is a schematic partial end view illustrating a braid structure of the sleeve of FIG. 1 with an abrasion test tool arranged for contact therewith;
[0027] FIGS. 5A and 5B illustrate abrasion tests performed on a sleeve to determine if the sleeve meets predetermined specification requirements; and
[0028] FIG. 6 is a table listing different braid sleeve structures constructed in accordance with various aspects of the invention.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0029] Referring in more detail to the drawings, FIG. 1 illustrates a braided tubular textile sleeve 10 constructed according to one aspect of the invention. The sleeve 10 includes a plurality of multifilament yarns, referred to hereafter as simply as multifilaments 11 , braided with a plurality of monofilament yarns, referred to hereafter simply as monofilaments 12 , to form a tubular wall 14 of the sleeve 10 . The wall 14 is braided in seamless fashion and thus, has a circumferentially continuous, uninterrupted outer surface 16 and an inner surface 18 defining an inner tubular cavity 20 extending axially along a central longitudinal axis 22 between opposite ends 24 , 26 of the sleeve 10 . The cavity 20 is sized for receipt of an elongate member 28 to be protected, such as a wire harness, fluid or gas conveying conduit, cable or the like. The synergies created between the multifilaments 11 and the monofilaments 12 provide the sleeve 10 with an outer surface density as low as about 500 g/m 2 , resulting in a cost effective sleeve and a highly flexible wall 14 , while at the same time providing the wall 14 with a tough outer surface 16 that is highly resistant to abrasion, such that the wall 14 of the sleeve 10 is able to protect the elongate member 28 contained therein against damage. Evidence of such toughness under elevated temperatures has been empirically verified in abrasion testing, discussed in more detail below.
[0030] The wall 14 can be constructed having any suitable length and diameter and is braided having a tight braid structure to increase the impermeability of the wall 14 against the ingress of external fluid and/or debris into the cavity 20 without need for a secondary coating of any kind. Accordingly, the sleeve 10 is made cost effective given its ability to provide protection to the elongate member 28 without need for multiple wall layers or a secondary coating material. In accordance with one aspect of the invention, the wall 14 is formed with bundled, dual strands or ends of the multifilaments 11 in side-by-side, mirrored relation and with single strands or ends of the monofilaments 12 , wherein the bundled multifilaments 11 are braided with the single monofilament strands 12 . FIG. 3 illustrates the individual bundles of dual strands DS of multifilaments 11 , shown schematically, in relation to the single strands SS of monofilaments 12 , shown schematically. As such, if an equal number of carriers are used to braid the wall 14 , such as 36 carriers for the multifilaments 11 and 36 carriers for the monofilaments 12 , by way of example and without limitation, each of the carriers of the multifilaments 11 has 2 ends of the multifilaments 11 , while each of the carriers of the monofilaments 12 has a single end of the monofilaments 12 . Accordingly, the multifilaments 11 and monofilaments 12 are braided with one another in a respective ratio of 2:1 ends. As such, it should be recognized the two ends of multifilaments 11 on each carrier are braided in side-by-side, mirrored relation with one another as though they are a single, common yarn.
[0031] The monofilaments 12 play in important role in the performance of the sleeve 10 and provide the sleeve 10 with its ability to resist abrasion, and function in part to lock the bundled multifilaments 11 in their “as braided” location during use, thereby enhancing the abrasion resistance of the wall 14 provided by the “locked and fixed” high tenacity multifilaments 11 . The multifilaments of polyester are provided having a linear density of between about 1000-1200 dTex, and in one exemplary embodiment were provided having an 1100 denier and a count-related yarn tenacity between about 60-85 cN/tex, wherein cN/tex yarn=cN/tex fiber (×) substance utilization % (/) 100, and in particular, were provided as high tenacity PET sold under the tradename Diolen®, by way of example and without limitation. The ability of the monofilaments 12 to lock the multifilaments 11 in position is due in part to the diameter of the monofilaments, which is provided between about 0.35-0.40 mm, and also the high modulus and rigidity in the radial direction (lack of ability to be radially deformed elastically) of the monofilaments (it is to be understood that although the monofilaments 112 are rigid in the radial direction that they remain flexible along their length, thereby allowing the sleeve 10 to remain highly flexible), having a relatively high Young's Modulus of elasticity, such as about 3 GPa, and a tenacity between about 40-55 cN/tex, and in one particularly preferred embodiment, by way of example and without limitation, high tenacity thermoplastic polyamide, such as high tenacity nylon. With the monofilaments 12 having a relatively high Young's Modulus, they are able to be embedded into the multifilaments 11 , thereby acting to lock the multifilaments 11 in place in an “as braided” location. To the contrary, if the monofilaments were provided having a relatively low Young's Modulus, the monofilaments would be more elastic, both axially and radially, and as such, would not be embedded into the multifilaments to the degree needed to lock the multifilaments in an “as braided” location. As such, with a relatively low Young's Modulus monofilament, an increased surface area density of the wall would be needed, such as about 900 g/m 2 , to provide the degree of abrasion resistance needed to pass the abrasion test and to protect the elongate member against damage. Of course, it should be recognized that an increased surface area would come at an increased cost, add bulk, and further, would reduce the flexibility of the sleeve.
[0032] Tests used to validate the abrasion resistance of the sleeve 10 include a tool 30 , having an applied mass of 200 g, that is oriented with the length of the tool 30 extending generally transversely to the longitudinal axis 22 of the sleeve 10 ( 5 A and 5 B). In accordance with one test, the tool 30 is moved along the length of the sleeve 10 at a frequency of 10 Hz, such as shown in FIG. 5A , and in another test, the tool 30 is moved at a frequency of 10 Hz in a sawing type motion, transversely to the length of the sleeve, across the width of the sleeve 10 , such as shown in FIG. 5B . The number of cycles for a new sleeve test is 144,000. A sleeve 10 constructed in accordance with the invention, as described above, is able to pass the test having a rating of 4 or higher on a scale of 0-5. Passing the test requires only a partial wearing of the underlying braided yarns take place during testing, without breaking through the thickness or severing of any of the underlying braided yarns, and of course, no damage to an elongate member contained in the sleeve 10 can result. The abrasion resistance test procedure performed on a sleeve constructed in accordance with the invention, which passed the test with a score of no less than 4, is as follows:
Test #1: Abrasion resistance per D44 1959, category D per S21 5101 Procedure: The following was performed on a minimum of 3 samples per abrasion direction:
A sample was cut to a length of approximately 100 mm. The sample was installed over a PA hose of the nominal sleeve size and a steel mandrel was inserted inside the hose. The assembly sample/hose/mandrel was mounted on the sample holder. The abrasive tool, Category D (PA66GF30 plastic edge), was mounted on the tool holder such that the angle tool/sample was 90°. The contact tool/sample was created applying a mass of 200 g. The oven was pre-heated at 120° C. before testing. After stabilization of the oven temperature, the test was launched. After 144,000 cycles (4 hours) of abrasion test at 10 cycles/sec (stroke of 10 mm), per longitudinal (type A or grating) and transverse (type B or sawing) directions, The sample was visually inspected for grading from 0 to 5.
[0043] During construction of the sleeve 10 , including braiding the bundled multifilaments 11 and single monofilaments 12 with one another, as discussed above, the desired length of the sleeve 10 is preferably cut to length in the braiding process. Cutting the desired finished length of the sleeve 10 in the braiding process has been found to facilitate maintaining the round outer peripheral shape of the sleeve 10 , thereby facilitating insertion of the elongate member 28 through the cavity 20 .
[0044] The table illustrated in FIG. 6 shows six (6) different samples produced in accordance with various aspects of the invention, by way of example and without limitation, with the mean sleeve diameter listed in column B; the various types of multifilament and monofilament yarns listed in columns C and D, respectively, along with the number of carriers and ends of respective yarns; the braid wall mass listed in column E; and the braid wall density listed in column F.
[0045] It is to be understood that the above detailed description is with regard to some presently preferred embodiments, and that other embodiments readily discernible from the disclosure herein by those having ordinary skill in the art are incorporated herein and considered to be within the scope of any ultimately allowed claims. | A protective textile sleeve and method of construction thereof is provided. The sleeve has a flexible, tubular wall of braided yarns. At least some of the yarns are provided as a plurality of monofilaments and at least some of the yarns are provided as a plurality of multifilaments. The plurality of multifilaments are braided in a plurality of separate bundles. Each of the bundles includes at least two multifilaments. The monofilaments are embedded into the multifilaments during the braiding process to lock the multifilaments in an “as braided” location to prevent shifting of the multifilaments during application and during use, thereby enhancing the abrasion resistance of the sleeve wall. | 3 |
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of priority under 35 U.S.C. §119 of German Patent Application 10 2007 025 808.0 filed Jun. 2, 2007, the entire contents of which are incorporated herein by reference.
FIELD OF THE INVENTION
[0002] The present invention pertains to a connection head of an anesthetic breathing system with an inner gas duct and with an outer gas duct which is arranged concentrically thereto, in the connection area between an absorber and the connection head.
BACKGROUND OF THE INVENTION
[0003] A connection head of the type is known from DE 10 2004 020 133 B3 (corresponding to U.S. application Ser. No. 11/058,624). The connection head is used to connect an absorber cartridge to an anesthetic breathing system or to also replace a used absorber cartridge with a new one even during operation. Valves are used for this purpose within the connection head; on the one hand, these valves bridge over the gas ducts to the absorber in the form of a bypass when the absorber is removed, so that no gas can escape from the anesthetic breathing system. On the other hand, a gas connection is established to the absorber when the absorber cartridge is connected to the connection head.
[0004] The valves, which establish or interrupt gas connections, are accommodated in the prior-art connection head in a cylindrical cavity, which is accessible only from the side of the anesthetic breathing system. To clean the valves, the connection head must first be separated from the anesthetic breathing system so that the cover plate fixing the valves can be removed. This makes handling difficult during cleaning, especially because the cover plate is screwed to the housing of the connection head.
SUMMARY OF THE INVENTION
[0005] The basic object of the present invention is to improve a connection head of the type mentioned such that it has a simple design and can be easily taken apart.
[0006] According to the invention, a connection head is provided for an absorber of an anesthetic breathing system. The connection head comprises a pivotable mount for connecting the absorber to the connection head as well as an inner gas duct in a connection area between the absorber and the connection head and an outer gas duct arranged concentrically to the inner gas duct in the connection area between the absorber and the connection head sleeve, wherein a valve means can be opened towards the absorber. The connection head has a guide sleeve that receives the valve means in the line of the gas ducts. The valve means has a sealing surface for connection to the inner gas duct and a shut-off means in the outer gas duct. The valve means is actuated by the absorber via the sealing surface in such a way that the valve means performs a lifting motion. A sealing ring is provided for connection to the guide sleeve. The sealing ring has a one-piece design with a first sealing area directed towards the outer gas duct and with a second sealing area cooperating with the valve means as the shut-off means. The second sealing area is provided on an underside of the guide sleeve.
[0007] The valve means may comprise a hollow cylinder of a stepped design comprising a first cylinder section with a larger cross section forming a ring duct with the guide sleeve, a second cylinder section with a smaller diameter, the second cylinder section being closed off with the sealing surface and a ring section formed between the first cylinder section and the second cylinder section. The ring section forms a valve disk for an inner sealing lip of the sealing ring in the second sealing area. The hollow cylinder may have, at the end facing away from the sealing surface, a flow valve, which opens towards an interior space of the hollow cylinder. The flow valve and the shut-off means may be formed from the inner sealing lip and the ring section and are switched into the opening position with the absorber inserted in the connection head.
[0008] A locking means may be provided for fixing the pivotable mount in a use position. The locking means may comprise a barb at the pivotable mount and a locking element. The locking element may be actuated by a release element. The locking element may extend behind the barb and release the barb when the release element is actuated by pressure thereon.
[0009] The advantage of the present invention is essentially that the valve means, which switches over the path of the gas when the absorber is inserted into the connection head, is inserted into a guide sleeve, which is open towards the absorber and which is subsequently fixed by a sealing ring, which can be attached to the guide sleeve, within the guide sleeve. The sealing ring has, in a one-piece design, two sealing lips, an outer sealing lip of which, which has a great strain path, lies in contact with an outer valve crater (seat) of the absorber, while an inner sealing lip, which is located in an annular space between the valve means and the guide sleeve, cooperates with an outer ring section of the valve means as a valve disk for the inner sealing lip such that the path of gas through the annular space is interrupted when the absorber has been removed. The ring section lifts off from the inner sealing lip when the absorber is inserted and connected to the connection head, and the path of gas is released.
[0010] It is especially advantageous that two sealing areas can be formed due to the one-piece design of the sealing ring and that the corresponding sealing lips can be individually adapted to the particular requirements. For example, the outer sealing lip, which lies on the outer valve crater, must have a great strain path in order to be able to compensate differences in height between the outer valve crater and the guide sleeve. The differences in height are due to manufacturing tolerances between the absorber and the connection head. The inner sealing lip must be such that it possesses good sealing properties together with the outer ring section.
[0011] An exemplary embodiment of the present invention is shown in the figures and will be explained in more detail below. The various features of novelty which characterize the invention are pointed out with particularity in the claims annexed to and forming a part of this disclosure. For a better understanding of the invention, its operating advantages and specific objects attained by its uses, reference is made to the accompanying drawings and descriptive matter in which a preferred embodiment of the invention is illustrated.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] In the drawings:
[0013] FIG. 1 is a sectional view showing a connection head with an absorber;
[0014] FIG. 2 is a perspective sectional view schematically showing a connection area between the connection head and the absorber according to FIG. 1 ;
[0015] FIG. 3 is a sectional view showing an absorber connected to the connection head;
[0016] FIG. 4 is perspective sectional view showing the connection area between the connection head and the absorber according to FIG. 3 ;
[0017] FIG. 5 is a perspective sectional view showing the underside of the connection head with the locking element inserted; and
[0018] FIG. 6 is a perspective view of the locking element according to FIG. 5 .
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0019] Referring to the drawings in particular FIG. 1 schematically shows a longitudinal section of a connection head 1 with a valve means 2 and with an absorber 4 accommodated in a pivotable mount 3 .
[0020] FIG. 2 schematically illustrates the connection area between the connection head 1 and the absorber 4 . The connection head 1 has a housing 5 with a connection piece 6 for connection to an anesthetic breathing system, not shown more specifically in FIG. 2 ; a guide sleeve 7 , which accommodates the valve means, and a ring-shaped locking element 8 within the housing 5 with a release button 9 .
[0021] The mount 3 , which receives the absorber 4 , has a barb 10 , which snaps into a wall section 11 of the locking element 8 . To connect the absorber 4 to the connection head 1 , the absorber 4 is pushed into the mount 3 and pivoted in the direction of the connection head 1 . Reference is made in this connection to DE 10 2004 020 133 B3, which is part of this specification (corresponding to U.S. application Ser. No. 11/058,624, filed Feb. 15, 2005, is also hereby incorporated by reference).
[0022] The absorber 4 has an inner gas duct 12 with an inner valve crater 13 and an outer gas duct 14 arranged concentrically thereto with an outer valve crater 15 . The gas ducts 12 , 14 describe the flow paths through the absorber 4 .
[0023] The inner gas duct 12 extends within the connection head 1 through the interior space of the valve means 2 and the outer gas duct 14 in an annular space between the valve means 2 and the guide sleeve 7 . A sealing ring 16 , which has an outer sealing lip 17 directed towards the absorber 4 , and an inner sealing lip 18 , which is in contact with an outer ring section 19 of the valve means 2 , is located on the underside of the guide sleeve 7 . The ring section 19 is located between a first cylindrical wall section 20 of the valve means 2 with a larger cross section and a second cylindrical wall section 21 with a smaller diameter, which adjoins same. The wall sections 20 , 21 and the ring section 19 together form a valve housing 201 of the valve means 2 . The inner sealing lip 18 and the ring section 19 form a second sealing area 24 and are designed to interrupt the flow of gas in the annular space as a shut-off means when the absorber 4 has been removed from the connection head 1 .
[0024] The second wall section 21 is provided with an elastomer ring 22 at its free end, which extends in the direction of the absorber 4 . When the absorber 4 is pivoted in the direction of the connection head 1 , the outer sealing lip 17 lies on the outer valve crater 15 and forms a first sealing area 23 . The elastomer ring 22 is located in this position of the absorber 4 on the inner valve crater 13 .
[0025] A flow valve 31 with a valve body 25 , which is in contact with a sealing lip 26 , is located on the top side of the first wall section 20 of the valve means 2 . The valve body 25 is pressed by a compression spring 27 against the sealing lip 26 . The valve body 25 is in contact with a projection 29 of the housing 5 via spacers 28 . Due to fixation by means of the spacers 28 , the valve body 25 always has a fixed position in relation to the housing 5 . The flow valve 31 opens when the valve housing 201 is displaced in relation to the valve body 25 in the direction of the spacers 28 . In the position of the absorber 4 shown in FIG. 2 , the path of gas 30 runs via the inner gas duct 12 through the free spaces between the spacers 28 to the outer gas duct 14 .
[0026] FIG. 3 shows the connection head 1 with the absorber 4 connected.
[0027] FIG. 4 illustrates the connection area between the connection head 1 and the absorber 4 , corresponding to FIG. 3 , in a longitudinal section. Identical components are designated by the same reference numbers as in FIGS. 1 and 2 . In the coupled state, the barb 10 has snapped into the wall section 11 of the spring element 8 . The outer valve crater 15 is in contact with the outer sealing lip 17 . The inner valve crater 13 is located at the elastomer ring 22 and presses the valve housing 201 of the valve means 2 upward against the force of the compression spring 27 . Since the valve body 25 is supported at the projection via the spacers 28 and thus remains in its original position, the sealing lip 26 lifts off from the valve body 25 and the flow valve 31 is opened. At the same time, the ring section 19 separates from the inner sealing lip 18 and the second sealing area 24 is opened. The path of gas 30 from the anesthetic breathing system now leads via the opened flow valve 31 into the inner gas duct 12 and to the absorber 4 . The backflow takes place via the outer gas duct 14 , the opened second sealing area 24 and the annular gap between the valve means 2 and the guide sleeve 7 back into the anesthetic breathing system. The outer sealing lip 17 is designed as a lip seal with a large deformation area in order to reduce sealing forces, which must be overcome when the mount 3 is coupled with the connection head 1 , on the one hand, and to compensate differences in height in the form of manufacturing tolerances, on the other hand.
[0028] With the absorber 4 uncoupled, the sealing ring 16 is pulled off from the guide sleeve 7 downward for cleaning purposes and the valve means 2 can be removed and taken apart for cleaning purposes. No tool is necessary for the disassembly. The components of the connection head 1 can be manufactured from plastic according to the injection molding process and can therefore be manufactured at a very low cost as a result.
[0029] FIG. 5 shows a bottom view of the connection head 1 with the valve means 2 removed and with the mount 3 removed in view “A” according to FIG. 2 . The mount 3 is fastened pivotably in the bushes 32 of the housing 5 . The locking element 8 has spacing elements 33 , which are in contact with a leaf spring 36 , the leaf spring 36 being supported on projections 34 of the housing 5 .
[0030] FIG. 6 illustrates the locking element 8 in a perspective view. The locking element 8 comprises a rigid frame 35 , to which the likewise rigid spacing elements 33 are fastened. When applying pressure to the release button 9 , the frame 35 and the wall section 11 are displaced in the direction of arrow 37 against the spring force of the leaf spring 36 , FIG. 5 . The stroke of the locking element 8 is limited by a contact surface 38 , which is in contact with the housing 5 at maximum deflection, FIG. 5 . When applying pressure to the release button 9 , the barb 10 , FIG. 2 , is released.
[0031] While a specific embodiment of the invention has been shown and described in detail to illustrate the application of the principles of the invention, it will be understood that the invention may be embodied otherwise without departing from such principles. | A connection head for an absorber ( 4 ) of an anesthetic breathing system has a simple design and can be easily taken apart. A valve device ( 2 ) is inserted into a guide sleeve ( 7 ), which is open towards the absorber ( 4 ). A sealing ring ( 16 ), which has two sealing areas ( 23, 24 ) and fixes the valve means ( 2 ) within the guide sleeve ( 7 ), is arranged on the underside of the guide sleeve ( 7 ). | 0 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a completion application of co-pending U.S. Provisional Patent Application Ser. No. 60/566,673, filed Apr. 30, 2004, the entire disclosure of which is hereby incorporated by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] This invention relates to an enclosed structure that may be attached to the exterior wall of an existing or new building, such structure typically being referred to as a patio enclosure, sunroom, or solarium. More particularly, the invention relates to a patio enclosure having a high proportion of windows and a roof and constructed from a framework of composite members and insulating wall panels. Even more particularly, this invention relates to composite plastic members extruded from material having improved thermal characteristics and stability.
[0004] 2. Description of Prior Art
[0005] Patio enclosures and sunrooms are not new to the building industry. When adding onto or remodeling an existing home or other structure, many people turn to the patio enclosure or sunroom. Such rooms are relatively easy for trained technicians to construct and are inexpensive when compared to other improvements that can be made to a home, such as remodeled bathrooms or kitchens. These enclosures have traditionally been constructed of an aluminum frame with windows or glass sections. Aluminum sunrooms are shaped with vertical walls that have a curved transition to the roof, although most may have a marquee roof or gable type roof.
[0006] The following U.S. Patents and Patent Publication illustrate various enclosures, non-metallic structural elements used in constructing these enclosures, and the materials used in forming the non-metallic structural elements: Nos. 5,497,594 to Guiseppe et al.; 5,848,512 to Conn; 6,003,279 to Schneider; 6,015,611 to Deaner et al.; 6,117,924 to Brandt; 6,248,813 to Zehner; 6,412,227 to DeZen; 6,337,138 and 6,344,504 to Zehner et al.; 6,460,309 to Schneider; and 2002/0066248 to Buhrts et al.
[0007] As discussed in Schneider U.S. Pat. No. 6,003,279 and U.S. Pat. No. 6,460,309, aluminum framed enclosures have several disadvantages. The main problem is poor thermal efficiency. Due to the high rate at which aluminum conducts heat, a room constructed from aluminum cannot stay comfortably cool in the summer, without air conditioning, or warm in the winter, without supplemental heating. This drawback results in dramatically increased cooling and heating costs. Further, a high rate of heat transfer can lead to condensation on the interior surfaces of the aluminum structures. Moreover, many of the windows in aluminum frame type sunrooms are generally installed in such a way that the windows cannot be opened and no screens are present.
[0008] Another disadvantage is high maintenance. Aluminum must be painted if chipped and is easily dented. Construction of aluminum rooms is a major disadvantage as well. Because of the nature of the metal, the aluminum pieces must be assembled with external fasteners. External fasteners increase the time of assembly and degrade the overall aesthetics of the room.
[0009] In light of these various deficiencies, Schneider U.S. Pat. No. 6,003,279 discloses various structural members, which include reinforced and non-reinforced polyvinyl chloride extrusions, which are joined together at joints using hardware which cannot be seen from inside or outside the enclosure, thereby enhancing the aesthetic appeal of the enclosure. Further, Conn U.S. Pat. No. 5,848,512 and Schneider U.S. Pat. No. 6,460,309 disclose an I-beam that is extruded from plastic and configured such that the vertical spacer wall defines a central passageway that extends between the opposite ends of the beam. Schneider U.S. Pat. No. 6,460,309 is directed to a vinyl roofing system utilizing the channel beam to interconnect roof panels with a roof cap.
[0010] In obviating certain of the problems associated with unwanted condensation and thermal conductivity, many framing enclosure designs have used a “sleeve” approach wherein the aluminum elements and sections are enclosed within PVC frames. A drawback to this approach is that the aluminum reinforcing still has to be properly insulated from the rest of the vinyl profile. This approach results in massive, bulky sections with high material costs.
[0011] A need continues for a low maintenance sunroom/patio enclosure that is economical, has improved thermal efficiency and minimizes thermal condensation arising from thermal transmittance, provides sliding or double hung windows and/or doorway, has an aesthetic appearance, conceals connecting fasteners, and employs fastening components that are easy to use when erecting the enclosure.
[0012] Accordingly, a primary object of this invention is the provision of a sunroom/patio enclosure that obtains the benefits of framing elements and sections of polymeric and like material, and achieves the above noted needs.
[0013] Another object of this invention is the provision of a sunroom/patio enclosure using frame elements formed of composite PVC to allow parts to have smaller cross-sections without a great degree of internal reinforcing.
[0014] As is known, steel has much lower conductivity to thermal loss than aluminum, and has higher strength properties with lower cost.
[0015] Accordingly, another object of this invention is the elimination of most if not all aluminum components from the enclosure product, such as by replacing some frame connecting elements with galvanized steel.
[0016] Another object of this invention is the provision of an enclosure structure that shows no screw heads on the inside or the outside of the enclosure room.
[0017] A further object of this invention is the provision of an enclosure structure comprised of composite PVC to combine the properties of wood with the maintenance free advantages of vinyl.
SUMMARY OF THE INVENTION
[0018] Briefly described the objects of the present invention are achieved, in a room structure for attachment to the exterior wall of a building mounted on a foundation adjacent to said exterior wall, said room structure comprising an upright frame assembly having an upper end and formed by at least one enclosure wall and a roof structure extending between said exterior wall and the upper end of said frame assembly, said frame assembly including at least one vertically disposed support member, the improvement wherein
said support member comprises an assembly of an H-beam and a closure member, each said support member and H-beam being comprised of a single piece of composite and having a like vertical height, said H-beam being formed by a spacer wall and a pair of webs, the spacer wall extending between the webs and disposed inwardly and between the outer edges of the webs wherein to form a pair of outwardly open squared-C channels, and said closure member being formed by a pair of sidewalls and a base wall, the sidewalls extending from opposite edges of the base wall wherein to form a squared-C cross-section, the closure member being snap-fittable in a friction fit into one of the squared-C channels of the H-beam to substantially close said channel and in a manner that the exterior base wall of the closure member and the edges of webs of the squared-C channel into which interfitted are substantially coplanar.
[0023] According to an important aspect, the H-shaped beam and C-shaped closure member are extruded from a composite PVC plastic.
[0024] A preferred embodiment according to this invention is the provision of a beam structure for a patio enclosure, the beam structure comprising
a support member and a filler member, said members extending longitudinally and each of a generally constant cross-sectional shape, said support member having a base wall, first and second walls disposed generally perpendicularly to the plane of said base wall, and outer end faces disposed parallel to the plane of said base wall, the first and second walls cooperating to define an outwardly open longitudinally extending channel sized to receive said filler member, and said filler member having a base member and a pair of upstanding sidewalls adapted to frictionally engage and form a snug snap-fit engagement with a respective of said first and second walls, the base member and the outer end faces forming a generally continuous surface following said interfitment.
[0028] According to an aspect of this embodiment, the support member comprises a generally H-shaped beam member and the channel thereof has a squared-C cross-section, the filler member has a squared-C cross-section, and the H-shaped beam member and filler member are extruded, or injection molded from a synthetic wood composition.
[0029] According to another aspect of this invention, the H-shaped beam member has a pair of flange members, each forming a respective of said outer end faces, and the exterior surfaces of the outer end faces and the exterior surface of the filler member are clad with vinyl cap stock.
[0030] Another preferred embodiment according to this invention is the provision of modular wall for a patio enclosure formed as an add-on extension to an existing structure supported on the ground and having framing structure for at least one of a window or door, the modular wall comprising:
a longitudinally extending upper and lower track beam, the lower track beam being supported on the ground, a pair of vertically extending corner posts, each post having an upper and lower end portion and forming at least one outwardly open channel, at least one vertically extending H-beam disposed between the posts and defining a pair of separated wall sections, the H-beam having an upper and lower end portion and forming a pair of opposed outwardly open channels, said wall section including a lower and an upper C-shaped cross-beam, a lower and an upper wall panel, and the framing structure sandwiched between said wall panels, said cross-beam having opposite longitudinal ends, a base having an outer surface, and an outwardly open channel, said lower and upper wall panel having, respectively, upper and lower edges engaged with the outer surface of a respective cross-beam, lower and upper edges interfitted within the channel of said lower and upper track beam, and vertically disposed side edges interfitted within the channels of said corner posts and H-beam, first means for positioning and securing the lower end portions to the lower track beam and the upper end portions to the upper track beam, wherein said track beams are disposed in generally parallel horizontal relation, said corner posts are secured and positioned at the opposite longitudinal ends of the lower track beam, and the channels of said H-beam and said corner posts are facing one another, second means for enclosing the outwardly open channels of said corner posts and said H-beam wherein to cover said first means, at least in part, and third means for positioning and securing the opposite ends of the cross-beams to said corner post and H-beam.
[0038] According this embodiment of the invention, the second means comprises a filler beam of predetermined cross-section, which filler beam is frictionally interfit in a snug-fit into the respective channel to form an exterior surface that appears to be unitary.
[0039] Further, and according to an important aspect of this embodiment, the upper and lower track beams, the corner posts, the H-beam, the cross-beams, and the filler beam are extruded or injection molded from a synthetic wood PVC composition and have exterior surfaces selectively clad with vinyl cap stock.
[0040] Another preferred embodiment according to this invention is the provision of a wall joint for a patio enclosure, which enclosure is formed as an add-on extension to an existing structure, supported on the ground, and has framing structure for at least one of a window or door, the wall joint comprising:
a first pair of longitudinally extending upper and lower track beams and a second pair of longitudinally extending upper and lower track beams, the first pair of track beams being disposed at a right angle to the second pair of track beams and each said lower track beam being supported on the ground, a vertically extending corner post, said post having a lower and upper end portion and forming outwardly open first and second channels, the channels being disposed at right angles to one another, a vertically extending first and second wall section, each said wall section including upper and lower end portions that are juxtaposable with and extend along a respective pair of said lower and upper track beams, said first wall section having a first vertical edge that is juxtaposable with the first channel of said corner post and at least one framing structure, and said second wall section having a second vertical edge that is juxtaposable with the second channel of said corner post and at least one framing structure, first means for securing and positioning the lower end portion of said corner post and said lower track beams to said support wherein the first and second channels are juxtaposed with the ends of the lower track beams, second means for securing and positioning the upper end portion of said corner post to said upper track beams, third means for enclosing the outwardly open first and second channels of said corner post wherein to cover each said first and second means, at least in part, and fourth means for connecting the wall sections to the track beams and said corner post.
[0048] Another preferred embodiment according to this invention is the provision of a new and improved extruded article, said article produced by extruding a cellulosic inorganic filled plastic composite, the composite consisting of a bound together mixture of polyvinyl chloride, a cellulosic material, selected from sawdust, finely pulverized dried wood, and wood flour, baking flour, and a binder.
[0049] A further preferred embodiment according to this invention comprises a kit for constructing an enclosure to the exterior wall of an existing structure, said kit comprising:
a plurality of wall panels of predetermined height, width, and thickness, framing structure, such as for providing at least one window or door, as required, a plurality of elongated track beams, the track beams forming upper and lower end caps of front and side walls formed by the kit and each having a central track, a plurality of vertical uprights of H-shaped cross section, the H-beam forming two opposed outwardly opening C-shaped channels, a plurality of C-shaped cross-beams, the cross-beam having an outwardly open C-shaped channel, a plurality of corner posts of generally square cross section and forming two outwardly opening channels of squared-C cross-section, means for positioning and securing the wall panels, framing structure, track beams, H-beams, C-shaped cross-beams, and corner posts to one another and the support structure, and a plurality of closure members of squared-C cross-section, the closure members being snap-fittable into a respective C-shaped channel provided in the H-beam and corner post, wherein to close the channel and form a unitary appearing exterior.
[0058] Preferably, and according to this embodiment of the invention the track beams, H-beam, corner-post, C-shaped cross-beam, and closure members of the kit are extruded or injection molded of a composite PVC, with predetermined exterior surfaces of each clad with a protective surface of vinyl.
BRIEF DESCRIPTION OF THE DRAWINGS
[0059] These and other objects, advantages and features of the invention will become apparent from the following description taken in conjunction with the accompanying drawings, which illustrate specific embodiments of the invention. In the drawings:
[0060] FIG. 1 is an exploded perspective view of a patio enclosure positioned for assembly using a variety of frame members and structural elements according to this invention;
[0061] FIGS. 1A-1E are cross-sectional views of structural elements used in assembling the enclosure of FIG. 1 ;
[0062] FIG. 2 is an elevation view showing the front side of the patio enclosure of FIG. 1 , following assembly to an exterior wall of a house;
[0063] FIG. 3 is an elevation view showing the left side of the patio enclosure of FIG. 2 ;
[0064] FIG. 4 is an elevation view showing the right side of the patio enclosure of FIG. 2 ;
[0065] FIG. 5 is a section view of the front wall taken along line 5 - 5 of FIG. 2 showing an H-beam disposed vertically, C-shaped upper and lower track members disposed horizontally, L-shaped flanges securing the opposite ends of the beam to the track members, and connections that extend along the top and bottom ends of the front wall of the enclosure and connect the upper track member to the lower front end of the roof structure and the lower track member to the ground structure;
[0066] FIG. 6 is a section view of the front wall taken along line 6 - 6 of FIG. 2 showing a C-shaped channel member disposed horizontally, the bottom edge of a window channel supported on the channel member, the upper and lower edges of a front wall panel received in the channel member and lower track member, and a connection, which extends along and connects the front wall of the enclosure to the ground structure;
[0067] FIG. 7 is a section view of the front wall taken along line 7 - 7 of FIG. 2 showing the upper track member, the top edge of the window channel supporting a channel member, the upper and lower edges of a the front wall panel received in the upper track member and the channel member, and a the connection between the upper track member and the roof structure;
[0068] FIG. 8 is a section view of the right side wall taken along line 8 - 8 of FIG. 4 showing a channel member, the top edge of a window channel supporting the channel member, the upper and lower edges of a right side wall panel received in the upper and channel members, and a connection between the upper track member and the roof structure, which extends along and between the lower front and upper rearward end of the roof structure of the enclosure;
[0069] FIG. 9 is a section view of the front wall taken along line 9 - 9 of FIG. 2 showing two window channels separated by an H-beam, and a pair of L-shaped flanges and a pair of E-shaped filler channels interfitted into oppositely facing outwardly open channels of the H-beam, the flanges for connecting the H-beam to the a track member, and thus to the ground structure;
[0070] FIG. 10 is a section view of the front wall taken along line 10 - 10 of FIG. 2 showing opposite edges of front wall panels and an L-shaped flange for connecting the beam to the ground structure interfitted into oppositely facing outwardly open channels of the H-beam;
[0071] FIG. 11 is a section view of the right side wall taken along line 11 - 11 of FIG. 4 showing a C-shaped track member connected to the exterior wall, a window channel, and an E-shaped filler and an L-shaped flange interfitted into an outwardly open channel of the track member;
[0072] FIG. 12 is a section view of the right side wall taken along line 12 - 12 of FIG. 4 showing a track member disposed vertically and connected to the exterior wall and a vertical edge portion of an enclosure panel interfitted into the track member;
[0073] FIG. 13 is a section view of the left side wall taken along line 13 - 13 of FIG. 3 showing a C-shaped track member disposed vertically and connected to the exterior wall, a C-shaped track disposed vertically and connected by an L-shaped flange to the lower track, and thus to the ground structure, and a wall panel having opposite vertical edges interfitted into opposed channels of the track members; and
[0074] FIG. 14 is a section view taken along line 14 - 14 of FIG. 3 showing a box-shaped corner post having opposed channels for connecting the left and front wall panels to one another, and L-shaped flanges for connecting the corner post to a track member of the enclosure.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0075] Referring to FIGS. 1 and 2 - 4 there is shown an exemplary patio enclosure, generally indicated at 10 , constructed according to the present invention. The enclosure 10 is supported from below by a load-bearing substrate 12 and laterally by the exterior wall 14 of an existing structure, such as a house (not shown). The load bearing substrate 12 may be a concrete slab, wood decking, or the like.
[0076] As shown in FIG. 1 , the enclosure 10 comprises a front wall 16 , a pair of lateral side walls 18 and 20 , and a sloping roof 22 . The walls 16 , 18 and 20 project upwardly from the substrate 12 where they are joined to the roof 22 . The sidewalls 18 and 20 have opposite lateral ends connected, respectively, to the house and a respective lateral end of the front wall 16 .
[0077] The walls and roof of the enclosure 10 are formed by a framework of joined horizontal and vertical structural members, such as structural filler wall panels 24 and roof panels 26 , multiple pairs of sliding glass windows 28 , framed screens 30 for each pair of windows (one shown), and an optional conventional door assembly 32 .
[0078] Each wall panel 24 is generally rectangularly shaped and has a central body 24 a of polymeric material, such as foam, and outer layers 24 b and 24 c wherein to provide a wall panel element of generally uniform thickness. The thickness of the wall panel 24 is such that the lateral edges thereof may be interfitted into the squared-C channel of a structural element according to this invention (described in detail below). Preferably, both of the layers 24 b and 24 c are clad with vinyl.
[0079] Preferably and according to this invention, certain of the structural elements used in this assembly are shown and identified on FIGS. 1A-1E . These structural elements include a corner post 34 , a post or H-beam 36 , a base track 38 , a cross-beam channel 40 , and a filler 44 . As will be discussed below, nails, screws and like threaded fasteners, flanges and like connecting elements are used to connect the structural elements together and form modular wall portions and the patio enclosure 10 .
[0080] Preferably and according to this invention, each of these structural elements are comprised of a composite PVC material and extruded into the desired cross-section and length. Subsequent to extrusion, a vinyl surface is clad to the exterior surfaces of the structural elements. The resulting element is sometimes referred to a composite PVC element. The structural elements made from the composite PVC material are generally stronger than wood, metal, or vinyl, has no adverse heat conduction, and has the durability of vinyl. Although extrusion is a preferable method, these elements may be injection molded.
[0081] According to one aspect, the composite material is comprised of a bound together mixture of cellulosic material (esp. sawdust or like finely pulverized dried wood, such as wood flour) and baking flour (e.g., the fine powdery foodstuff obtained by grinding and sifting the meal of a grain, especially wheat, used chiefly in baking). Suitable woods for sawdust are resin-free softwoods such as pine, fir and spruce, and to a lesser extent, hardwoods. The percentage of sawdust to baking flour, measured by weight or volume, and a binder and/or mixer ingredient used to hold the composition together is determined, in part, on a cross-section property of the structural element that is desired (i.e., thickness and area moment of inertia of the cross-section).
[0082] Referring to FIG. 1A , the corner post 34 is box-like, in cross-section, axially elongated, and formed by walls 46 , 48 , 50 and 52 . The walls intersect with one another to form a square central opening 54 and outwardly open squared-C shaped channels 56 and 58 for receiving the lateral edge of a wall panel 24 . The walls 46 and 52 form an exterior corner with the outwardly facing surfaces 46 a and 52 a thereof clad with vinyl.
[0083] Referring to FIG. 1B , the post or H-beam 36 is axially elongated and includes a central body 60 and a pair of transverse flanges 62 and 64 , which define oppositely facing squared-C shaped channels 63 and 65 . The exterior surfaces 62 a and 64 a of the flanges 62 and 64 are clad with vinyl and the central body 60 is hollow and defines a central rectangular-shaped passageway 66 .
[0084] Referring to FIG. 1C , the base track 38 is axially extending and includes a flat base member 68 having opposite lateral edges 68 a and 68 b and a pair of opposed L-shaped arms 70 and 72 , the arms being spaced apart and defining a track 73 therebetween. The L-shaped arms 70 and 72 are generally perpendicular to the plane of the base member 68 and define opposed squared-C shaped channels 70 a and 72 a that are in faced relation and communicate with the central track 73 . The arm 70 extends along and upstands from the lateral edge 68 a of the base member 68 . The arm 72 extends along and upstands from the base member 68 at a location inwardly of the lateral edge 68 b of the base member 68 wherein to define an offset base portion 69 . The exterior surfaces 70 b, 72 b, and 69 a, respectively, of the upstanding arms 70 and 72 and the offset base portion 69 are clad with vinyl.
[0085] Referring to FIG. 1D , the cross-beam channel 40 is axially extending and forms a generally squared-C shape in cross-section. The channel 40 includes a base member 76 and a pair of opposed upstanding legs 78 wherein to define a squared-C shaped channel 80 having a width adapted to receive the lateral edge of a wall panel 24 interfitted therewithin. The base member 76 is hollow and defines a central rectangular shaped passageway 77 . The exterior surface 76 a and 78 a, respectively, of the base member 76 and the legs 78 are clad with vinyl.
[0086] Referring to FIG. 1E , the filler 44 is axially extending and generally E-shaped in cross-section. The filler 44 includes a flat base 82 and three upstanding legs 84 , 86 , and 88 , the legs 84 and 88 being outer legs and upstanding from the opposite respective lateral edges of the filler, and the leg 86 being a central leg upstanding from a central location of the base 82 . The legs 84 and 86 , and the legs 86 and 88 , respectively, cooperate to form two squared-C shaped channels 85 and 87 . The exterior surface 82 a of the central base member 80 is clad with vinyl.
[0087] As shown in FIGS. 1 and 2 - 4 , the front, left, and right walls 16 , 18 and 20 of the enclosure 10 are assembled by he formed by various of the structural elements 36 , 38 , 40 , 42 , and 44 and wall panels 24 . As shown in FIG. 2 , the front wall 16 is defined by and extends between two box-beams 34 and includes two H-beams 36 wherein to define three modular wall portions, each portion including a window framing 28 and wall panels 16 . As shown in FIGS. 3 and 4 , the left and right side walls 18 and 20 are defined by and extend between a box beam 34 and a base track 38 . The right side wall 20 includes an H-beam 36 and defines two modular wall portions and the left side wall 18 includes optional door framing 32 .
[0088] As shown in FIG. 5 , the modular wall portion of the front wall 16 includes elongated lower and upper base tracks 38 , denoted as 38 a and 38 b and disposed horizontally, and an H-beam 36 disposed vertically. L-shaped flanges 90 are secured at predetermined locations along the lower and upper base tracks 38 a and 38 b and serve to properly space and position the H-beams 36 and the corner box-beams 34 in a manner to receive wall panels 24 , or door or window framing 28 and 32 .
[0089] The lower base track 38 a is positioned atop the substrate 12 and secured thereto by an L-shaped flange 90 and at least one threaded fastener 92 . The flange 90 has opposite legs 90 a and 90 b and is nested in the track 73 formed between the opposed L-shaped arms 70 and 72 of the base member 68 with the flange leg 90 a seated atop the base member 68 of the base track 38 a and the flange leg 90 b extending vertically upwardly from the base track. Fasteners 92 extend through the flange leg 90 a, the base member 68 , and into the substrate 12 .
[0090] The upper track 38 b forms the upward vertical extension of the front wall 24 and is secured, at least in part, to the upward vertical extension of the H-beam 36 . As with the track 38 a, the upper track 38 b is provided with positioning flanges 90 .
[0091] The lower and upper ends 36 a and 36 b of the H-beam 36 are nested into a respective track 73 formed between the opposed L-shaped arms of each respective track 38 a and 38 b. So positioned by the flanges 90 secured to the lower and upper tracks 38 a and 38 b, the flange leg 90 b extending upwardly from the lower track 38 a is threadably secured to the lower end portion of the H-beam, and the flange leg 90 b extending downwardly from the upper track 38 b is threadably secured to the upper end portion of the H-beam.
[0092] A wall panel 24 is inserted downwardly into the opposed squared-C channels of successive H-beams 36 or corner post 34 and H-beam 36 . As can be seen in FIG. 5 , the protective outer layers 24 b and 24 c of the panel 24 are generally coextensive (i.e., flush) with the outward extension of the flanges 62 and 64 of the H-beam 36 .
[0093] The upper track 38 b forms a closure cap and support for a forward lower front end of the roof structure 22 . To provide support and sealing, an axially elongated, generally cylindrical strand 94 of elastomeric material is supported atop the upper track 38 b, on the extended base portion 74 thereof, and supports and moisture seals the roof structure 22 of the enclosure 10 .
[0094] As shown in FIG. 6 , a cross-beam channel 40 is interfitted onto and supported atop the upper lateral horizontally extending edge of the wall panel 24 . Further, window framing 28 is thereafter supported atop the cross-beam channel 40 .
[0095] As shown in FIG. 7 , a cross-beam channel 40 is interfitted onto the lower lateral horizontally extending edge of the wall panel 24 . Further, window framing 28 is thereafter abutted against the cross-beam channel 40 . In a manner described in connection with FIG. 5 , the upper track 38 b and strand 94 are shown in relation to the roof structure 22 .
[0096] As shown in FIG. 8 , the upper track 38 b of the right wall 20 is shown supporting the roof structure 22 . The right wall 22 includes an upper track 38 b, a wall panel 24 , and window framing 28 . Because the upper end of the right wall 20 angles upwardly and is supporting relation with the bottom surface of the roof structure 22 , the support strand 94 is not needed. Further, the base portion 74 extends in a direction outwardly of the enclosure 10 .
[0097] As shown in FIG. 9 , an H-beam 36 is shown separating two window framing sections 28 , and L-shaped flanges 90 are connected to opposite sides of the central body 60 extending between the flanges 62 and 64 of the H-beam. Importantly, an E-shaped filler 44 is inserted into each of the two opposed squared-C channels 63 and 65 of the H-beam.
[0098] According to this invention, the cross-sections of the filler 44 and the squared-C channels 63 and 65 of the H-beam are such that the filler 44 forms, with the flanges and channels of the H-beam, a closure that makes the beam and filler elements appear as one unitary structure. That is, the base surface 82 a of the filler 44 and the surfaces formed by the lateral edges of the respective flanges 62 and 64 are substantially coextensive with one another. The interfitment between the outer legs 84 and 88 of the filler 44 and the interior facing walls of the flanges 62 and 64 results in a snug frictional snap-fit interengegement.
[0099] As shown in FIG. 10 , the opposed squared-C channels 63 and 65 of an H-beam 36 are shown receiving opposite respective lateral vertical edges of a respective pair of panels 24 , and a flange 90 positioning the H-beam 36 .
[0100] As shown in FIG. 11 , a track 38 is disposed vertically and connected to the existing structure 14 , and window framing 28 of the left side wall 18 is shown relative to the track.
[0101] Further and according to this invention, the cross-sections of a filler 44 and the central track 73 of a base track 38 are such that the filler 44 forms, with the central track 73 , a closure that makes the two elements appear as one unitary structure. The interfitment between the outer legs 84 and 88 of the filler 44 and the interior facing ends of the L-shaped arms 70 and 72 of the base track 38 results in a snug snap-fit frictional interengagement.
[0102] As shown in FIG. 12 , a base track 38 is threadably fastened to the exterior wall 14 and the vertical lateral edge of a wall panel 24 is interfitted within the track 73 formed between the opposed L-shaped arms 70 and 72 of the base track 38 .
[0103] As shown in FIG. 13 , a base track 38 , a wall panel 24 , and a cross-beam channel 40 extend vertically upwardly from their connection to a horizontally extending lower base track (not shown). The opposite lateral vertically disposed edges of the wall panel 24 are interfitted within the central track 73 and squared-C channel 80 formed by the vertically disposed base track 38 and cross-beam channel 40 . A flange 90 positions and secures the lower end of the cross-beam channel 40 relative to the lower base track. Further, the cross-beam channel 40 positions associated window framing 28 .
[0104] As shown in FIG. 14 , a corner post 34 connects the vertical edges of the left and front walls 18 and 20 . The corner post 34 extends vertically upwardly from the substrate 12 and is connected to two base tracks 38 a, the base tracks extending horizontally along the substrate and at right angles to one another. The two base tracks 38 a are connected to the substrate 12 by L-shaped flanges 90 in a manner described above. One L-shaped flange 90 is disposed in one base track 38 a and has a vertical leg 90 a received in the squared-C channel 56 and threadably fastened to the wall 48 of the corner post beam. The other L-shaped flange 90 is disposed in the other base track 38 a and has a vertical leg 90 a received in the squared-C channel 58 and threadably fastened to the wall 50 of the corner post beam.
[0105] An E-shaped filler beam 44 is snugly interfitted within the squared-C channels 56 and 58 wherein to provide the corner post 34 with a clean aesthetic appearance.
[0106] As shown in FIG. 1 , the roof 22 is generally rectangularly shaped, angles downwardly from the exterior wall 14 , and is generally coextensive with the front and side walls 16 , 18 and 20 of the enclosure 10 . The roof structure includes severally generally rectangularly shaped roof panels 26 , a rearward channel bracket 98 , a forward channel bracket 100 , left and right end brackets 102 and 104 , and a plurality of H-beams 36 . The roof panels 26 are as described for the wall panels 24 . Further, the channels 98 and 100 and end brackets 102 and 104 are comprised of a composite PVC, as described herein above.
[0107] The rearward channel bracket 98 is mounted to the exterior wall 14 and has an outwardly open channel 98 a adapted to receive rearward lateral edges of the roof panels 26 and rearward end portions of the H-beams 36 .
[0108] The forward channel bracket 100 has an outwardly open channel 100 a adapted to receive forward lateral edges of the roof panels 26 and forward end portions of the H-beams 36 . Further, the channel bracket 100 includes an upwardly open channel 100 b which forms a gutter or trough for directing water from the roof
[0109] The left and right end brackets 102 ands 104 have outwardly open channels 102 a and 104 a, respectively, for receiving the lateral edge of a roof panel 26 .
[0110] As assembled, the rear channel 98 is connected to the exterior wall 14 . The rectangular roof panels 26 have their opposite longitudinal edge portions interfitted within the channel 63 and 65 of a respective H-beam 36 , or left and right end bracket 100 and 102 , and their opposite lateral edges ends interfitted within a channel 98 a and 100 a in the rearward and forward channel brackets 98 and 100 . The opposite ends of the channel brackets 98 and 100 are connected to the opposite ends of the left and right end brackets 102 and 104 .
[0111] As contemplated herein, the patio enclosure 10 may be advantageously supplied to the user in kit form, ready to go and for assembly to an existing structure. The kit for constructing an enclosure to the exterior wall of an existing structure would generally comprise the various structural elements as described in detail herein above.
[0112] In particular, the kit would comprise a plurality of wall panels 24 of predetermined height, width, and thickness, framing structure 28 and 32 for at least one window or door, a plurality of elongated track beams 38 , the track beams forming upper and lower end caps of front and side walls 16 , 18 and 20 formed by the kit, a plurality of vertical uprights 36 of H-shaped cross section, a plurality of corner posts 34 , a plurality of C-shaped cross-beams 40 , a plurality of closure members 44 of squared-C cross-section, the closure members being snap-fittable into a respective C-shaped channel provided in the H-beam and corner post, and fasteners 90 and 92 for positioning and securing the wall panels, framing structure, track beams, H-beams, corner posts, C-shaped cross-beams, and closure members to one another and the support structure.
[0113] Preferably, and according to this embodiment of the invention, the track beams, H-beam, corner-post, C-shaped cross-beam, and closure members of the kit are extruded or injection molded of a composite PVC, with predetermined exterior surfaces clad with a vinyl. | An enclosed structure, such as a patio enclosure, sunroom, or solarium, is attachable to the exterior wall of a building, has a high proportion of windows and a roof, and constructed from a framework of composite members and insulating wall panels, the panels and wall members being extruded from material having improved thermal characteristics and stability. | 4 |
RELATED APPLICATION
This application claims the benefit of U.S. Provisional Application No. 60/230,840 filed on Sep. 7, 2000, the entire teachings of which are incorporated herein by reference.
This application is related to United States Patent Application titled: COMPUTER METHOD AND APPARATUS FOR PETROLEUM TRADING AND LOGISTICS by Girish Navani, James Harrison Stommel, Barry H. Cohn, Michael P. Evans, Donald A. Dietrich, Bruce A. Logan, Michael D. Allen, Charles C. Moore, Linus Hakimattar, Stephen J. Doyle, Wayne C. Bartel, Scott Folger, Nigel Johnson, Nigel Kidd, Khaled Zayadine, Vip Patel, Ken Rosen, Sean Collins and Vlad Mahalec and United States Patent Application titled: COMPUTER SYSTEM FOR PROVIDING A COLLABORATIVE WORKFLOW ENVIRONMENT by Girish Navani, Michael P. Evans, Donald A. Dietrich, Michael D. Allen, Charles C. Moore, Linus Hakimattar, Stephen J. Doyle, Wayne C. Bartel, Kevin Maher, Vip Patel, Ken Rosen and Vlad Mahalec all related applications filed on even date herewith and commonly owned by the owner of this application.
BACKGROUND OF THE INVENTION
Generally speaking, the petroleum industry involves three major players—(1) oil refineries, (2) crude oil and refined products traders/brokers and (3) service providers such as vessel owners/brokers, inspectors, terminal operators and pipeline companies. Each party typically uses internal procedures and proprietary means to conduct business/trading. Crude oil and petroleum product trading is not standardized, there are over 600 types of crude oil around the world.
Briefly, the oil refineries receive crude oil and process the oil into usable products and/or blendable components such as fuel oil, intermediate feedstocks and high grade gasoline. The refinery receives orders for various quantities of products specified by respective grade and quality. Also, the refinery schedules specific dates by which to fulfill the orders.
An analyst of the refinery uses internal and/or published standards to determine the necessary ingredients and quantities thereof to blend together to form an ordered product to specification. Next, he checks the refinery's inventory for availability of these ingredients in the desired quantities. He may find some ingredients, at the desired quantities, to be in inventory while other ingredients need to be obtained. The analyst cross references the ingredients of his order with that of other orders to account for any inventory which may be in common with the order he is processing. Thus it is a complex exercise to determine which ingredients and at what quantities are needed to be added to the inventory in order to fulfill each product order.
Further, a product marketer forecasts demand of products. A refinery planner evaluates refinery operation, output and available resources, and monitors/maintains appropriate inventory. Inventory may include (i) various crude oils, (ii) intermediate feedstocks usable for component blending and (iii) end products. The refinery planner wants to optimize the plant (refinery) and thus needs to determine what crude oils are going to give the best yield given the current plant configuration (distillation columns, catalyst crackers, etc.).
The supply trader or an outside broker has the task of obtaining the needed feedstock at the necessary quantities for inventory. For each needed feedstock, the supply trader has a target receipt date and a total dollar budget which is acceptable to the refinery (in order to economically and timely fill product orders). The supply trader contacts his network of suppliers for respective quotes (going rates) on available quantities of the needed feedstock. Typically, rates change daily or within a day. Sometimes the supply trader will look to purchasing piecewise quantities from plural suppliers which in the aggregate meets the total needed amount of a feedstock within the acceptable budget. Variation in quality, and the like, affect the quantities and the price that the trader will pay for a given feedstock. Also the trader needs to work with scheduling personnel to arrange for shipping of the quantities of the feedstock, from the various sources, so that the total needed amount arrives at the refinery by an acceptable date (the target receipt date).
As can be seen given the foregoing, the trader must make multiple phone calls to his suppliers and shippers and maintain a complex tally of costs, quantities and time schedules in order to accomplish his task. That is, by the time the trader makes a series of phone calls, e.g. to a first supplier, a second supplier, a shipper and then re-calls the first supplier, the unit price may have changed or the shipping vessel is no longer available. Consequently the trader must make adjustments, more phone calls and recalculate totals to ensure he is within budget/target (dollar and timewise).
Further there is a dynamic aspect of crude oil and petroleum product trading. In transit amounts of crude oil (or intermediate feedstock/components) may become available to the market where that amount is arriving too late to fulfill an original order. Various amounts of crude oil, intermediate feedstocks (components) or end products may become available in a disaster recovery situation. Traders/brokers use these offers and the results thereof in fulfilling (in full or part) original orders.
Further, there are various distribution points for petroleum products (e.g., gasoline) throughout the United States. Different distribution points carry different grades of products as a function of local and state regulations. The U.S. Department of Energy controls amounts in inventory at each of the distribution points. The federal agency determines what amounts of which products need to be shifted among the distribution points based on monthly to quarterly reports by the distribution points. Accordingly, the petroleum industry supply chain is illustrated in FIG. 5 and discussed later.
SUMMARY OF THE INVENTION
Currently lacking are automated means for effecting real-time crude oil and petroleum product trading, refining and logistics support. The present invention addresses this and other needs in the industry.
In particular, the present invention provides a non-client computer resident method for optimizing vessel scheduling by aggregating vessel information. At least some of the vessel information is automatically downloaded from an electronic source. The aggregated vessel information is stored in a vessel information database comprising vessel information database records. Information is obtained about a potential vessel contracting transaction. The vessel information database is searched in a real-time manner to match the potential vessel contracting transaction to at least one of the vessel information database records such that the vessel contracting transaction is optimized. At least one of the optimized vessel contracting transactions is then reported. Optimization factors used to produce the optimized vessel contracting transactions include lowest cost and fastest delivery.
The vessel information comprises at least one of: vessel availability, physical vessel specifications, standard port-to-port pricing, physical port specifications and vessel vetting information.
In one preferred embodiment, optimized vessel scheduling is provided as part of an overall transportation search and optimization system.
Benefits of the present invention include more accurate data and fewer typographical errors. Efficiency is improved as lag-time is squeezed out of supply chain operations. The graphical user interface is easier to use than conventional methods of vessel scheduling and consolidates the interface to aggregated vessel data. Real-time access to server-based vessel scheduling applications provides optimized results faster.
BRIEF DESCRIPTION OF THE DRAWINGS
The foregoing and other objects, features and advantages of the invention will be apparent from the following more particular description of preferred embodiments of the invention, as illustrated in the accompanying drawings in which like reference characters refer to the same parts throughout the different views. The drawings are not necessarily to scale, emphasis instead being placed upon illustrating the principles of the invention.
FIG. 1 is a schematic overview of a computer network in which the present invention is operated.
FIG. 2 is a block diagram of the preferred embodiment of the invention.
FIG. 3 a is an illustration of a deal negotiation system main screen of the present invention in the embodiment of FIG. 2 .
FIGS. 3 b and 3 c are illustrations of working screen views of respective operations in the deal negotiation system main screen of FIG. 3 a.
FIGS. 4 a and 4 b are schematic diagrams of trade deal objects and supporting tables employed in the embodiment of FIG. 2 .
FIG. 4 c is a flow diagram of the operations and screen views of FIGS. 3 a – 3 c based on the data structures of FIGS. 4 a and 4 b.
FIG. 5 is a schematic view of the supply chain and related roles in the petroleum industry.
FIG. 6 a is a block diagram of an arbitrage analyzer configured according to an embodiment of the present invention.
FIG. 6 b illustrates a graphical user interface for defining and viewing an arbitrage relationship configured according to a preferred embodiment of the present invention.
FIG. 6 c illustrates a petroleum trading, refining and logistics aware search engine configured according an embodiment of the present invention.
FIG. 7 is a flow diagram of an online analysis program supporting decision support tools of the preferred embodiment of the present invention.
FIG. 8 is a diagram of the hierarchical structure of the collaborative workflow environment configured according an embodiment of the present invention.
FIG. 9 illustrates the various participants involved in a refinery upset collaborative workflow process configured according an embodiment of the present invention.
FIG. 10 illustrates the various participants involved in a closed deal tracking collaborative workflow process configured according an embodiment of the present invention.
FIG. 11 a illustrates a collaborative workflow environment view of collaborative workflow processes.
FIG. 11 b illustrates a view of business processes associated with a specific collaborative workflow process.
FIG. 11 c illustrates a view of an activity associated with a specific business process.
FIG. 12 is an illustration of a graphical user interface for vessel searching and optimization configured according to an embodiment of the present invention.
FIG. 13 a illustrates the CBAT-G tool being used to evaluate components for blending.
FIG. 13 b illustrates the CBAT-G tool being used to integrate to decision support tools providing vessel scheduling and optimization services for components and blends.
DETAILED DESCRIPTION OF THE INVENTION
Illustrated in FIG. 1 is a plurality of networks 19 a , 19 b , 19 c . Each network 19 includes a multiplicity of digital processors 11 , 13 , 15 , 17 (e.g., PC's, mini computer and the like) loosely coupled to a host processor or server 21 a , 21 b , 21 c for communication among the processors within that network 19 . Also included in each network 19 are printers, facsimiles and the like. In turn, each host processor 21 is coupled to a communication line 23 which interconnects or links the networks 19 a , 19 b , 19 c to each other to form an internet. That is, each of the networks 19 are themselves loosely coupled along a communication line 23 to enable access from a digital processor 11 , 13 , 15 , 17 of one network 19 to a digital processor 11 , 13 , 15 , 17 of another network 19 . In the preferred embodiment, the loose coupling of networks 19 is a global computer network, such as the Internet.
Also linked to communication line 23 are various servers 25 a , 25 b which provide to end users access to the Internet (i.e., access to potentially all other networks 19 , and hence processors 11 , 13 , 15 , 17 connected to the Internet). The present invention is a software program 31 operated and connected through a server 27 to the Internet for communication among the various networks 19 and/or processors 11 , 13 , 15 , 17 and other end user connected through respective servers 25 . In the preferred embodiment, the server 27 is, for example, Sun Microsystems UltraSparc (e.g., Enterprise series), or a multiplicity of similar such servers running HyperText Transfer protocol (HTTP) server software to support operation of present invention program 31 .
Upon an end user logging onto program 31 through a common Internet protocol, program 31 generates an initial screen view and displays the same to the end user. Depending on the unique user ID that the end user enters during user logon, a different initial screen, view and subsequent series of screens, per user, are displayed. The unique user ID is preferably assigned to the user during a registration process prior to use of the program 31 . Through the registration process the type of user (plant manager, analyst, oil trading broker, . . . etc.), security level or access (read, write, modify) privileges and other determinations about the user are made. Based on these determinations, the features and tools of program 31 most usable and pertinent to the particular user are tagged/flagged and linked to the user's unique user ID. Upon a login bearing the unique user ID, the program 31 formulates an appropriate initial screen view for the corresponding user. The preferred embodiment is a role-based system defined by user type.
Referring to FIG. 2 , a table, set of pointers, or other means 35 are employed to cross reference unique user ID to user type, security/access level, and/or features and tools of program 31 . Various data structures and constructs are suitable and are in the purview of one skilled in the art. In the preferred embodiment, user type (in user ID table 35 ) is defined in a role-based definitions table 38 . Definitions table 38 is indexed by user type, and for each user type, definitions table 38 specifies a corresponding business or industry role and respective tasks of that role. Thus, for example, a user type “B” may be defined in table 38 to correspond to the role of “Broker”, and definitions table 38 specifies the corresponding tasks of creating deals, negotiating deals, closing deals, etc., for that user type and role.
The possible tools, links, subsequent screens and other information that an initial screen view may have are discussed next. It is understood that various combinations of the following are employed for various end users depending on the use determinations made at the registration stage and tied (through tables 35 and 38 ) to the unique user ID per user.
Continuing with FIG. 2 , program 31 is formed of an assembly of user-interactive applications programs 37 (namely, the deal negotiation system 37 a , the scheduling application 37 b and collaborative workflow application 37 c ), corresponding screen views 33 and user interface. As mentioned above, depending on user ID (and hence user types), the different application programs 37 provide different support tools 39 and screen views 33 for use by the end user during execution of the respective application program 37 .
For example, the deal negotiation system 37 a provides a main screen view 41 as illustrated in FIG. 3 a . The deal negotiation system main screen 41 enables end users to create, view, discuss, negotiate and close a trade (i.e., define and complete a transaction) for a desired quantity and grade of crude oil, intermediate feedstock or petroleum product. To that end, the deal negotiation system main screen 41 and series of subscreens (from tabs) and windows (from drop down, pop-up or cascading menus) provide an online trading process that allows end users to buy or sell crude oil and petroleum products online and to handle other necessary operations related to petroleum trading. As such, the deal negotiation application 37 a allows end users to conduct trading in a private and/or public marketplace in a secure-data, real-time environment.
In the preferred embodiment, the deal negotiation system main screen 41 displays information about bids and offers (of an end user) according to markets in which they are currently posted. That is, the “U.S. Crudes” tab (subscreen view) 43 a displays the end user's current trade deals involving U.S. crude oil. The “International Crudes” tab (subscreen view) 43 b displays the end user's current trade deals involving international crude oil. The “U.S. Products” tab (subscreen view) 43 c displays the end user's current U.S. petroleum products trade deals. The “International Products” tab (subscreen view) 43 d displays the end user's current international petroleum product trade deals. The “Intermediates” tab (subscreen view) 43 e displays the end user's current intermediates feedstock trade deals. The “What's New” tab (subscreen view) 43 f displays trades on which the end user has not yet acted.
For each posted trade deal 45 of a given tab 43 (subscreen view), the deal negotiation application 37 a displays:
(i) Name (abbreviated or the like) of the counter party making or receiving a bid or offer,
(ii) type of trade (e.g., basis trade, index trade, fixed and flat trade or buy and sell trade),
(iii) grade of petroleum being traded,
(iv) geographic location where the crude oil, intermediate feedstock or petroleum product is being loaded or delivered,
(v) delivery terms and time period/date range (e.g., free on board (FOB); cost, insurance and freight (CIF); cost and freight (C&F); delivered (DLVD); delivered exship (DES); delivered duty paid (DDP); delivered duty unpaid (DDU)),
(vi) pricing basis used to determine final price of the closed deal, and
(vii) bid or offer information 55 . (to be associated to the pricing basis (above)
Bid and offer information 55 includes:
(i) status of a bid/offer (e.g., new/not yet acted on by recipient, active trade/can be negotiated and closed, inactive trade/closed by other trading party, expired trade/no longer available for negotiating, on hold/temporarily unavailable for negotiating or acceptance). Symbols, icons or other indicators may be employed to indicate each different status;
(ii) quantity being traded;
(iii) quantity unit of measure for the posted material; and
(iv) bid/offer amount that is over or under market or index price. A bid or offer amount may alternatively be indicated as a flat amount instead of as a differential.
For filtered views of the foregoing trade data, the deal negotiation system 37 a provides Tips check box 47 , first view list 49 , second view list 51 and grades 53 features. Tip check box 47 enables the “mouse-over display of bid and offer information 55 in expanded or spelled-out fashion instead of abbreviations and symbols, when the cursor is moved across (hovers over) the posted trades (deals) 45 . The first view list 49 controls the types of trade deals displayed. In the preferred embodiment, the types of trade deals that can be selected are: public, private and all active. The second view list 51 further filters the types of trade deals of the first view list 49 between all and self-posted trades 45 . The grades feature 53 controls display of posted trades 45 based on user-selected grade of petroleum.
The deal negotiation system 37 a also provides various operations on trades (deals) 45 , individually or as a group (e.g., in a common market, tab/subscreen 43 ). The operations are implemented through pop up menus, pull down menus, icons, buttons or other working areas in the screen views. In the preferred embodiment, the operations include “view”, “create”, “hold”, “resume”, “cancel”, “negotiate”, “delivery term details” and “add to decision support tools”, each described next.
The “view” operation 40 ( FIG. 3 a ) displays details of a user-selected offer or bid of a posted trade (deal) 45 displayed in the deal negotiation system main screen 41 or subscreens 43 . The displayed detailed information about the selected trade includes the trade type, the trade commodity details, market and pricing details, quantity and trader information.
The “create” operation 42 displays a working area in which to add a trade deal 45 , i.e. allows the end user to create an offer or bid in a desired marketplace. Inviting selected individuals from a deal negotiation system suppliers address book and/or private address book and buddy list. Creating an offer is a seller's function that allows the seller to place the commodity on the deal negotiation system main screen 41 to one or more invited parties with the same price or separate privately offered quantity selling prices. Likewise, creating a bid is a buyer's function which enables the buyer to buy a commodity that may be available in the market to one or more invited parties. FIG. 3 b is illustrative of the working area 57 supporting the “create” operation 42 .
Preferably in the working area 57 to add a trade deal, the end user indicates either offer or bid and either public or private to define the nature of the new trade. A public trade deal is posted to all trader end users that log into, and are authorized to access, the Web server 27 running invention program 31 . In that case, a seller may obtain bids from all end users who are interested in bidding for the posted offer. A private trade deal is posted to a selected list of the server 27 end users (as further described below).
The working area 57 to add a trade deal 45 provides a field for the end user creating the trade (and hence the “originating user” ) to specify a campaign name or identifier for the new trade or group of trades. Next the originating user specifies a grade and geographic region (market) for the commodity being traded. In the preferred embodiment the market options are U.S. crudes, international crudes, U.S. products, international products and U.S. intermediates these categories have become more granular, for example US products has been divided into US gasoline and US distillate. The same will hold true for International Products. The originating user may select different predefined grades from these markets along with an optional default delivery location. In response the deal negotiation system 37 a populates the market region and grade fields with appropriate standard specifications and populates the delivery location field. Alternatively, the originating end user may type in a grade and corresponding specifications overriding the predefined standard specifications. Predefined templates of frequently executed trades will facilitate the way trades are posted and negotiated.
Next in FIG. 3 b , the originating user specifies delivery type, such as one of the standard delivery options of FOB, CIF, DLVD, etc. The end user also specifies the deal type such as a basis trade, fixed trade or index trade. The end/originating user defines delivery dates by indicating a start time and an end time of availability of the commodity being traded. Depending on the deal type, the delivery type information may vary. That is, if a basis deal type is specified, the end user may select an exchange and the contract month. If the index deal type is specified, the end user may select a pricing index and enter the pricing commodity in the working area 57 . If a fixed deal type is specified, then no further options are available for delivery. If a buy/sell option is specified, then the end user may further specify commodity trade details.
Next in FIG. 3 b the end (originating) user enters quantity and pricing information for the new trade deal. Included in the quantity is the unit of measurement. The pricing information includes the pricing basis and either the flat price or price differential above or below the Exchange (index) price. The pricing basis indicates how the published prices of an Exchange will be used to determine the pricing of the new trade. The pricing basis and pricing window may be, for example, price established by a settlement committee, the published Exchange price three days around the bill of lading, the published Exchange price of a designated month, the scheduled monthly average, and the like. An expiration hour or period of time may also be specified by the end/originating user. The system will keep count down and expire trades that are set to expire. The originating user may specify a different quantity, price and/or expiration time per trader to whom the subject new trade deal is posted.
Finally in FIG. 3 b , the originating user selects or otherwise specifies traders to whom the new trade deal is to be posted. This may be accomplished through a selection off of a drop down list of registered end users of program 31 or a private list of the originating user selected traders. At the end of entering the foregoing information in the working area 57 to add a trade deal 45 , the originating user completes the create operation 42 by signaling deal negotiation application 37 a to post the new trade 45 on the deal negotiation system main screen view 41 , either in the private or public sector accordingly. This selection process comprises the following sequence of events:
1. define the market and terms. 2. invite counter parties 3. set price/quantity/expiration 4. post trade(s)
After a trade is posted on the deal negotiation system invitations are sent to counter parties via e-mail, pagers, and other electronic devices.
Inviting Unlicensed PetroVantage Users to Trade
The system allows for a licensed PetroVantage User to “invite” and unlicensed PetroVantage User to a “Private” offering. The steps included are:
1. Licensed Trader sets up an Unlicensed Party in their PetroVantage Private Address Book, simultaneously creating limited access to their transactions posted to the PetroVantage deal negotiation system. 2. The Unlicensed Party becomes available to the licensed party only in the selection list in the Add A Trade application. 3. The licensed party may then select the unlicensed party to be included in a Private posting. 4. The Unlicensed Party receives an invitation to Trade via e-mail which includes a URL directing the unlicensed User to their private posting on the PetroVantage Deal negotiation system. 5. The Unlicensed User gains limited access to the PetroVantage System and only their Private postings. The Unlicensed User may then negotiate and close the deal with the licensed User. 6. The Unlicensed Users access expires over a time period with no activity
Referring back to FIG. 3 a , the “hold” operation 44 may be effected to one posted trade deal 45 or all posted trade deals 45 displayed and originally posted by the user in the deal negotiation system screen views 41 , 43 . An end user may hold only a trade deal 45 that he has posted and not trades posted by another trader user. The hold operation 44 changes the status indication (in bid/offer information 55 , FIG. 3 a ) and prevents counterparties from closing the trade deal 45 . The respective end user must resume a trade deal 45 before another trader may accept the trade deal 45 .
The “resume” operation 46 enables an end user to resume one or all trades 45 that the end user has on hold. Resuming a trade deal 45 through the resume operation 46 changes the status indication to active (in bid/offer information 55 , FIG. 3 a ) and allows other traders to close or otherwise act on the re-posted trade 45 .
The “cancel” operation 48 ( FIG. 3 a ) enables an end user to cancel one or all trade deals 45 that he has originated and posted to the deal negotiation system screen views 41 , 43 . Canceling a trade deal 45 permanently removes the trade deal 45 from the deal negotiation system screen views 41 , 43 . A canceled trade deal cannot be resumed. Only the originating user (original creator of the trade) may cancel a trade deal 45 , to remove it from the deal negotiation system screen views 41 , 43 of all end users.
Continuing with FIG. 3 a , the “negotiate” operation 50 affects the posted trade deal 45 selected by the end user. The negotiate operation 50 enables the end user to conduct trade 45 negotiations using a secure instant messaging. That is, the path toward closing a trade 45 requires a back and forth dialog between trading partners. Traditionally the trade negotiation involves discussions on issues such as the material quality and quantity, the delivery terms, the expected arrival and departure times, the parcel details, etc.
Thus in the present invention 31 , negotiating involves private message exchanges between two parties. The messages provide requested information and allow an end user and trading partners to exchange trading details in real time. In the preferred embodiment, the negotiate operation 50 provides a working negotiation window 59 as shown in FIG. 3 c . The working negotiation window 59 displays summary information about the respective trade deal 45 (i.e., deal identification name or number, trade status, deal type of the trade, grade, delivery location and starting date of the delivery and the trade market—U.S. vs. international crudes vs. products).
The working negotiation window 59 also displays buyer information or seller information as appropriate. The buyer information includes buyer name, commodity description/petroleum grade, pricing basis including exchange and month that the exchange price was published, the buyer's bid or offer amount equal to, above or below the exchange price, quantity the buyer wishes to bid on, pricing window for the bid, time that the bid will remain active/expiration date time. The seller's information includes seller's name, commodity description/petroleum grade, pricing basis, the seller's offered amount that is equal to, above or below the exchange price, quantity that the seller wishes to sell, pricing window for this offer, the amount of time that the offer will remain active, messages received from trading partners and a text field for entering an instant message to a trading partner.
Additional features of working negotiation window 59 include an automated warning, or trigger alert, to indicate when other end users are attempting to negotiate. Another feature enables the end user to invite additional traders to the current posted trade 45 .
Returning to FIG. 3 a , the “delivery term details” operation 52 enables an end user to view and modify the delivery terms of a posted trade 45 created by that end user. In the preferred embodiment, the delivery terms may be made flexible by applying a tolerance to the subject commodity's volume. To that end, the end user specifies a percentage of the total volume or an absolute minimum and maximum limit on the commodity's quantity through the delivery term details operation 52 .
The “add to decision support tools” operation 54 ( FIG. 3 a ) enables an end user to download trade deal information of a selected posted trade 45 to a selected support tool 39 . That is, trade information of a desired posted trade 45 may be shared across various working screens 33 and support tools 39 of invention program 31 without requiring the end user to re-enter and retype the information at each use of a feature or tool. The support tools 39 in the preferred embodiment are discussed later.
To accomplish the foregoing operations 40 , 42 , 44 , 46 , 48 , 50 , 52 , 54 and to display the functioning thereof, in deal negotiation system main screen view and subscreens 41 , 43 , the preferred embodiment employs the data structures (e.g., tables and objects) illustrated in FIGS. 4 a and 4 b . In particular there is a respective trade object 67 ( FIG. 4 a ) for each trade deal 45 posted on trade screens 41 , 43 .
Turning to FIG. 4 a , trade object 67 stores the following data regarding a respective trade deal 45 . Trade object 67 stores and may be indexed by originating user ID (i.e., the user ID of the end user who originally created the subject trade deal 45 ). The full spelling of the originating user's name is linked from table 35 to object 67 . Trade object 67 stores an indication of status for bid and offer information 55 in deal negotiation system screen views 41 , 43 . Per end user, trade object 67 stores a substatus indication of “cancel” where the given end user has applied the cancel operation 48 to the subject trade deal 45 .
Trade object 67 stores indications of whether the subject trade deal 45 is a bid or offer and a public or private trade. In the case of a private trade, the object 67 also indicates the originating user-specified invitees (recipients of the trade).
A deal ID 79 and originating end-user specified campaign name uniquely identifies the trade object 67 . Consequently deal ID 79 is used as an index or key to object 67 .
The trade object 67 stores deal specifications such as general market categories (i.e., U.S. crude oil, international crude oil, U.S. intermediate feedstocks and U.S. products), grade of commodity being traded, quantity, units of measure for the quantity and expiration of trade bid/offer. Trade object 67 also stores defining attributes such as delivery/load location and dates, delivery type, deal type and pricing (including index or basis, and differential relative to index/basis). Per trader, trade object 67 may indicate different deal types, pricing, quantity and expiration of the subject trade deal 45 as illustrated by the asterisks in FIG. 4 a.
A log 71 of instant messages and the like from negotiations in the subject trade deal 45 is stored and linked to object 67 at 69 . User ID of the traders involved in the negotiations/ messages are linked to the log 71 from the object's 67 list of invitees at 73 . Access to view and/or update is determined to be “private” based on the following rules:
A trader posting a bid or offer may view and update all active transactions posted by that trader.
A trader receiving a private bid or offer may view and post counter bids/offers only against the private bid/offer made to that trader
Similarly, counter offers made in this trade deal 45 are logged at 75 . Details of each counter offer are stored in a respective trade object 67 n . Pointers or other link mechanisms are used from counter offers in log 75 to respective trade objects 67 n.
Once the subject deal is closed, the trade details at closing are indicated (directly or indirectly) at 77 and appropriately linked to trade object 67 . Confirmation to both the buyer and seller is generated and sent via e-mail. Using the unique ID of trade object 67 (i.e., deal ID 79 ), the closing trade details 77 are shared with collaborative workflow applications 37 c ( FIG. 2 ), scheduling application 37 b ( FIG. 2 ), back office applications and so forth.
One part of the closing details 77 is vessel or transportation information for shipping the subject commodity from seller to buyer. FIG. 4 b illustrates the data tables storing the supporting vessel information. For each vessel in deal negotiation application 37 a , vessel table 81 indicates a unique vessel identifier, class 85 of the subject vessel, waterway restrictions 91 , schedule of the subject vessel (including in-use periods indexed by deal ID 79 of closed deals 45 from deal negotiation system screens 41 , 43 ) and cost rate. Also vessel table 81 indicates the last cargo carried by the subject vessel and whether the vessel is cleaned after that load. A history data portion in vessel table 81 indicates name of vessel, owner's name and captain's name. The historical data is optionally hidden from display to end-user traders to keep the subject vessel anonymous for scheduling purposes.
Class 85 of a vessel is defined by supporting class definitions table 83 . For each class 85 , class table 83 indicates load capacity, vessel dimensions, hull structure (e.g., double hulled, . . . ) travel rate and load rate. According to the indicated vessel dimensions and hull structure, vessels of the subject class are allowed or limited access to certain waterways and ports. The class definition table 83 together with a port table 87 and processing rules 89 are used to determine specific waterway restrictions per vessel in vessel table 81 .
Port table 87 specifies each port by location, harbor depth, pipe availability and other accommodations. Local and federal government rules governing waterway restrictions are specified in processing rules 89 for rules-based generation of restrictions 91 . Processing rules 89 are applied to a given class 85 (from class definition table 83 ) across all ports in port table 87 and produce the list of waterways/ports from which the given class 85 of vessels is restricted. The resulting list is indicated at 91 for vessels of the given class 85 .
Turning now to FIG. 4 c , the operations 40 , 42 , 44 , 46 , 48 , 50 , 52 , 54 and working views of the deal negotiation system 37 a are supported by trade objects 67 ( FIG. 4 a ) as follows. In step 95 , per end user login, deal negotiation application 37 a gathers trade objects 67 with the corresponding user ID in the object originating user ID field or invitee field. The deal negotiation system 37 a uses the data from the gathered trade objects 67 to form the deal negotiation system screens 41 , 43 . In particular, deal negotiation application 37 a displays the trade deals 45 corresponding to the gathered trade objects 67 and omits from view, the trade deals 45 corresponding to gathered trade objects 67 with substatus equal to “cancel” (from a cancel operation 48 ). Further deal negotiation application 37 a arranges the subject trade deals 45 according to market indicated in the corresponding trade objects 67 attribute (US/International Crude oil, U.S. Intermediate feedstocks and U.S. products, FIG. 4 a ).
In step 96 , the deal negotiation system 37 a responds to the end user setting first view list 49 in FIG. 3 a . In response, deal negotiation application 37 a filters the displayed trade deals 45 based on public or private indication in corresponding trade objects 67 or on object status being set to “active” accordingly. In response to the end user setting the second view list 51 ( FIG. 3 a ), the deal negotiation application 37 a further filters the displayed trade deals 45 based on the originating user attribute of the trade objects 67 being set to the end user ID of the current user. Also in step 96 , the deal negotiation system 37 a filters the displayed trade deals 45 based on grade attribute of the corresponding trade objects 67 in response to the grade feature 53 ( FIG. 3 a ).
In step 97 , the deal negotiation system 37 a checks the Tips check box 47 of FIG. 3 a . If box 47 is set, then the deal negotiation system 37 a links to user data table 35 ( FIG. 2 ) and supporting standards lists (or other wise obtains the data contained therein) to display full spellings instead of abbreviations or symbols in screen views 41 , 43 . Full spellings of users/traders names, status indications, delivery type, deal type and pricing are available from respective lists as illustrated in FIG. 4 a.
In step 98 , the deal negotiation system 37 a responds to operations 40 , 42 , 44 , 46 , 48 , 50 , 52 , 54 ( FIG. 3 a ). In response to end user activation of the “view” operation 40 on a displayed trade deal 45 , deal negotiation application 37 a checks the status and expiration attributes of the corresponding trade object 67 . As appropriate, the deal negotiation system 37 a then composes a window view with trade type, commodity details, market and pricing details, quantity and trader information, each from respective attributes of the corresponding trade object 67 .
In response to end user activation of the “create” operation 42 on a displayed trade deal 45 , the deal negotiation system 37 a displays the working screen 57 ( FIG. 3 b ) to add a trade and prompts the end user to enter trade details. The deal negotiation system 37 a displays the predefined values/options for certain fields in response to end user request. The deal negotiation system 37 a at step 42 ( FIG. 4 c ) also populates the delivery/load location, deal type and delivery type fields of the displayed working screen 57 , with respective data from the user data table 35 and standards lists. Lastly, the deal negotiation system 37 a instantiates a trade object 67 with attributes set according to the values that the end user has entered into the displayed working screen 57 . The new trade object 67 corresponds to the new trade deal 45 created by the end user, and steps 95 and 96 use new trade object 67 to refresh the deal negotiation system views 41 , 43 to now include the newly created trade deal 45 corresponding to new trade object 67 .
In response to end user activation of the “hold” operation 44 on a displayed trade deal 45 , the deal negotiation system 37 a checks the originating user attribute of the corresponding trade object 67 . If the attribute is set to the user ID of the current end user, then the deal negotiation system 37 a changes trade object 67 status to hold. In turn, the corresponding trade deal 45 status (as displayed at bid/offer information 55 in views 41 , 43 ) is likewise changed to “hold”. Similarly, in response to end user activation of the “resume” operation 46 on a displayed trade deal 45 , the deal negotiation system 37 a checks the originating user attribute of the corresponding trade object 67 . If the attribute is set to the user ID of the current end user, then the deal negotiation system 37 a changes trade object 67 status from “hold” back to “active”. In turn the corresponding trade deal 45 status (as displayed at bid/offer information 55 in views 41 , 43 ) is likewise changed back to active.
In response to end user activation of the “cancel” operation 48 on a displayed trade deal 45 , the deal negotiation system 37 a checks the originating user attribute of the corresponding trade object 67 . If the attribute is set to the user ID of the current end user, then the deal negotiation system 37 a deletes the trade object 67 , thus removing the corresponding trade deal 45 from floor screen views 41 , 43 . If the attribute is not set to the user ID of the current end user, then the deal negotiation system 37 a sets the trade object substatus attribute to “cancel”. In turn, when steps 95 and 96 refresh the deal negotiation system screen views 41 , 43 , the subject trade deal 45 is omitted from display.
In response to end user activation of the “negotiate” operation 50 on a displayed trade deal 45 , the deal negotiation system 37 a checks the status and expiration attributes of the corresponding trade object 67 . If the status attribute is set to new or active and not on hold, then the deal negotiation system 37 a launches instant messaging and sets trigger alerts to other traders of the subject trade as indicated in the invitee attribute of the trade object 67 . The instant messaging is initialized between the originating user of the subject trade (as indicated in the originating user attribute of the trade object 67 ) and the current end user. The deal negotiation system 37 a obtains the originating user's email address from the user data table 35 as illustrated by the link to table 35 from the originating user attribute in trade object 67 in FIG. 4 a . The deal negotiation system 37 a further logs or stores each message at 71 in FIG. 4 a . As counter offers are made, the deal negotiation system 37 a follows create operation 42 steps to create a trade object 67 corresponding to the counter offer and links the counter offers 67 n to the subject trade deal 45 at 75 in FIG. 4 a.
In response to end user activation of the “Delivery Term Details” operation 52 on a displayed trade deal 45 , the deal negotiation system 37 a checks the status and expiration attributes of the corresponding trade object 67 . As appropriate, the deal negotiation system 37 a next checks the originating user attribute of the corresponding trade object 67 . If the attribute is not set to the user ID of the current end user, then the deal negotiation system 37 a composes a window with delivery location, delivery type and delivery dates information from respective attributes of the corresponding trade object 67 . Otherwise, the deal negotiation system 37 a composes a window for enabling the end user to specify tolerances as described previously.
In response to end user activation of the “add to decision support tools” operation 54 on a displayed trade deal 45 , the deal negotiation system 37 a checks the status and expiration attributes of the corresponding trade object 67 . If the status attribute is set to new or active and not on hold, then the deal negotiation system 37 a copies the contents of the corresponding trade object 67 and hence the specifications of the subject trade deal 45 and passes the copied data to the user-desired application 37 or support tool 39 . In particular, the deal negotiation system 37 a provides the copied data to scheduling application 37 b and support tools 39 b thereof, as well as to support tools 39 a of the deal negotiation system 37 a . The deal negotiation system 37 a can also provide the copied data to collaborative workflow application 37 c and support tools 39 c thereof.
Continuing with FIG. 4 c , at step 99 the deal negotiation system 37 a checks the status attribute of trade objects 67 . If a trade object 67 is found with a status attribute set to inactive/closed, then the corresponding trade deal 45 has been closed. The deal negotiation system 37 a accordingly copies the closed deal details 77 to collaborative work flow application 37 c , scheduling application 37 b and to back office applications and the like for generating the contracts, confirmations and other notifications of the final deal/trade. Word processing forms and merge document technology are employed to accomplish this. In one embodiment, the deal negotiation system 37 a at this juncture triggers an email message to the vessel broker/owner of the vessel indicated in the closed deal details 77 to secure/reserve the vessel. Other electronic messaging and confirmation is similarly suitable.
The deal negotiation system 37 a continues looping through steps 95 through 99 in FIG. 4 c as appropriate to support the end user activity in deal negotiation system screen views 41 , 43 (including application of operations 40 , 42 , 44 , 46 , 48 , 50 , 52 , 54 upon user command).
FIG. 5 is a schematic view of the supply chain and related roles in the petroleum industry. The petroleum supply chain 100 is composed of a trading & supply logistics component 102 , a refining operations component 104 and a marketing and distribution component 106 . Each of these components play a role in the supply of crude oil, intermediate feedstock and finished crude products to consumers.
Trading & supply logistics component 102 comprises the tasks of moving crude from a well head through a transportation system to a refinery. Crude typically transfers through vessels, pipelines and rail to terminals controlled by a terminal operator 108 . Alternately, the pipeline can be attached directly from the well head source to the refinery. Once the crude is stored in a terminal, barges, tanker ship, other pipelines or trucks are used to transport the crude oil to a refinery. Crude suppliers & brokers 112 interact with refinery supply schedulers 114 to coordinate the logistics (quantities, costs, time-frames, etc.) of supplying crude to a refinery.
Refining operations 104 process crude oil into intermediate feedstocks (e.g., butane) and finished crude products (e.g., jet fuel, gasoline) using distillation and/or catalyst-based procedures. Refineries are typically large and complex operations that require significant amounts of planning and analysis to perform at optimum levels. Refinery planning/scheduling 116 operations typically coordinate the logistics of obtaining crude for processing and allocating finished crude products for delivery in an efficient manner. Refinery economist or LP analyst 118 analyze the economics of the refinery operations. The analysis can be based on actual experience and knowledge of current situations and/or through the use of a liner programming (LP) model of the refinery.
During all aspects of the petroleum supply chain 100 , traders may buy or sell the crude, intermediate feedstock or finished product in order to maximize their profit. Paper crude traders 120 will trade a petroleum product in the petroleum supply chain 100 without any expectation of ever taking delivery of the commodity. Wet crude traders 124 , on the other hand, trade with an expectation of accepting delivery of a petroleum product for processing or sale. Various aspects of a petroleum trade may require credit & underwriting 122 in order to consummate the trade. Additionally, inspectors are employed at various point in the petroleum supply chain 100 to inspect and report on the quality and/or quantity of crude oil, intermediate feedstocks and petroleum products.
Marketing and distribution 126 move petroleum products produced by refinery operations 104 to retail and wholesale consumers. When the movement of petroleum products by ship is involved ship charter brokers 128 are employed to charter appropriate vessels to move the petroleum product to terminals/distribution points close to consumers. Tanker trucks often complete the movement by moving the petroleum products to their final destination (e.g., retail gasoline stations) where product marketers 126 have initiated marketing and sales campaigns to sell the petroleum products.
As mentioned above, the deal negotiation system 37 a provides support tools 39 for the various end users, including refinery supply traders (e.g., wet crude trader 124 ), product traders, brokers, plant analysts (e.g., refinery economist or LP analyst 118 ) and the like. The process of trade deal evaluation is supported by a set of decision support tools that help the end user to quickly evaluate crude oils and petroleum products for supply, blending and trading purposes. These tools include profit margin evaluation tools, component blending and trading tools, transport scheduling tools, arbitrage tools and automated search engine tools.
The decision support tools are a set of applications based on supply chain management technology, including Aspen Process Industry Modeling System (PIMS), the leading process industry planning software; Aspen MIMI; and Aspen Bulk & Retail (see Process Industry Modeling System Training Manual Part 1, Jun. 1, 1998 and Process Industry Modeling System Training Manual Part 2, Jun. 1, 1998) each by Aspen Technology, Inc., of Cambridge, Mass., the entire teachings of which are incorporated herein by reference. Using these tools, traders and schedulers can quickly identify and evaluate trading and logistics opportunities; specifically, these tools allow traders and schedulers to: estimate the potential value of specific crudes—or combinations of crudes—against a particular set of target refineries in a real-time market environment, evaluate the relative margins of available crudes in order to make the optimal supply decision, determine the value of intermediate feedstocks—either those in the market or those within the company's own processing facilities, find the most efficient way to acquire or dispose of product blend components and on-spec products to meet the company's current and strategic business needs and maximize the profit margins, evaluate discounted market blendstocks when they become available on short notice and enhance profitability with faster response to rapidly changing market opportunities.
Decision support tools can be used on a stand-alone basis or in conjunction with existing refinery planning and scheduling applications in order to leverage the more detailed linear program (LPs) programming models. The decision support tools provide: instant and secure access from any Web browser, integration with other software platforms (e.g., the deal negotiation system 37 a ), providing immediate access to the benefits of the collaborative workflow application 37 c . Only one click is required to access the decision support tools from the deal negotiation system 37 a.
Easy-to-use manual entry screens to input deal information gained from telephone or face-to-face conversations are provided. A library of international product specifications and crude assays is available. The ability to override any input data, including product and components specifications is provided. The decision support tools provide the ability to perform “what if” analysis and perform automatic pricing uploads for a given product and time period from all major price feed sources, including Platt's, NYMEX, and IPE, as well as third-party private forward price curves. The user can build complex price formulas to value un-priced commodities, based on qualities and relationships to other commodities.
In the preferred embodiments, various Crude Oil Evaluation (COE) tools are used to evaluate profit margins by refinery (e.g., COE-R) or by yield and quality (e.g., COE-Q). Additionally, evaluation tools are used to evaluate profit margins for Intermediate Feedstock Selection (IFS).
The Crude Oil Evaluation by Refinery (COE-R) tool is designed for Equity Crude Oil Marketers, Refinery Supply Traders and Trading company professionals who need to evaluate the current market value of a crude oil or blend of crude oils against multiple refineries' specification limits in various geographical locations. Since the refinery configuration, crude oils, product specifications, and prices are different for each region the user need the tool to evaluate the profit margins of refineries against the available crude oil or blend of crude oils. This information can be used to increase revenues by trading with refineries that can get the maximum benefits from a given batch of crude oil.
The Crude Oil Evaluation by Quality (COE-Q) tool enables traders to perform a quick evaluation of crude oil stocks and transportation costs in order to calculate the incremental net value of each crude oil based upon accurate yield and product quality. Using this tool, the trader performs simultaneous analysis of different crude oils to purchase and make a margin-based real time crude oil deal selection decision.
The Intermediate Feedstock Selection (IFS) tool allows traders to evaluate deal negotiation system components to ensure their compliance to the desired intermediate refinery component specifications, required volumes and the acquisition strategy. The trader can use this tool to perform an in-depth analysis of available components and their impact on the overall economics and logistics of a trade deal.
The component blending and trading tools include Crude Oil Blending and Trading (COBAT), multi-Component Blending and Trading (CBAT) tools for gasolines (CBAT-G), for fuel oils (CBAT-F) and for diesel fuel blends (CBAT-D).
The Crude Oil Blending and Trading (COBAT) tool is used to evaluate the most efficient combination of available crudes to meet refinery specification limits and to complete a refinery supply program. It enables traders to evaluate a wide range of crudes to determine the optimal combination of constrained raw materials needed to produce specific amounts of finished product at the lowest cost.
The purpose of blending crude oils is to produce certain types of feedstocks with specific characteristics. Refineries can use these composite feedstocks to optimize their profit while meeting the refinery specifications limits. To make the right selection of components and to optimize the use of downstream conversion units in a refinery, refinery supply traders 116 and analysts 118 need to consider the following: different refinery specifications, monthly refinery requirements, the variety of crude oils available in petroleum markets in geographical zones worldwide, the spectrum of crude oils to produce an intermediate petroleum product that would meet the refinery specifications and fluctuating oil prices.
Thus in the preferred embodiment, the COBAT tool is designed for traders and analysts who need to perform a quick “what-if” analysis to determine whether a particular crude or crudes being blended with other crudes will ensure the optimal final result that would meet the specifications and yield required by the processing refinery. Using COBAT, traders may evaluate a wide variety of crude oils to determine the optimal combination of raw materials needed to produce specific amounts of finished product at the lowest cost. It also helps them to evaluate the relative margins of crudes available in the market in order to make the right negotiating or purchasing decision.
In one preferred embodiment a trader selects and enters volume and characteristics of each of his current crude oils in stock, recent purchases, and any term supply he may have. This data can be entered manually or uploaded from the company mid office application. The trader sets the specification for the required final crude blend including various properties of the target composite. Preferably the properties include API quality, density, sulphur content, bulk pour point and others, estimation of quality and product yield of particular crude oil. Once the trader has defined characteristics of the desired composite(s), he selects crude oils whose combination might meet the refinery specification limits and produce the required volume of this composite at the lowest price. The negotiation operation discussed above allows the trader to upload information about a wide variety of crude oils available in the market and to see the current prices for each of these.
Upon trader command to evaluate, COBAT performs a “what-if” analysis to determine whether the target crude oil composite meets the specifications and yields required by the processing refinery. The trader makes a business decision based on the results of the analysis performed by the COBAT tool. The trader reviews the results and makes a purchasing decision. As soon as the trader has made a decision to buy, he employs the negotiation operation on the corresponding posted trade deal 45 of deal negotiation system screen views 41 , 43 to negotiate the deal. The trader closes the deal, saves the results and exits the application 37 a.
The multi-Component Blending and Trading (CBAT) tool is used to rapidly evaluate the marginal value of various blend stocks available in the market, providing traders with the most economic way to acquire or dispose of blend components to satisfy long/short positions. The tool functionalities may be used for various grades of gasoline including Reformulated, Conventional and CARB Gasolines (CBAT-G tool), Fuel Oils of various qualities (CBAT-F tool), and kerosene, jet fuel, and diesel fuels blends (CBAT-D tool). Restated, multi-component blending is a complex process that allows Traders and Analysts to make the best use of the available blendstocks in the market. Multi-component blending produces a variety of refined products, including different grades of gasoline, jet fuel oil, diesel oil, or lubricants. Each blend component has its own unique physical and chemical characteristics or properties. These components can be mixed with other components to create a finished product specification.
The Component Blending and Trading—Gasoline (CBAT-G) tool helps the trader to choose the type and quantity of each available blendstock needed to produce the desired volume of specific grades of gasoline. It also provides the actual value of each gasoline component, which allows the trader to calculate the marginal value of each gasoline component to produce or to buy.
By way of background, to produce what is known as finished gasoline, several components must be mixed together. Depending on what grade of gasoline one is trying to obtain, the target product may include six or more blending components. The quality and marketability of the finished product are determined by: (i) the product compliance with the gasoline specifications; and (ii) the product ability to meet local regulatory and economic requirements in different geographical locations.
Employing the CBAT-G tool, one can select and define the target product. In the preferred embodiment, the user scrolls up or down a predefined list to find the desired product to be made and selects the name of the desired gasoline grade from the list of predefined products. One may select as many products as desired, depending on how many gasoline blends are desired to be produced. Next, the user views the product specification for each selected gasoline blend. The product specification lists various gasoline properties, such as API gravity, octane number, sulfur content, etc. The user may review the gasoline blend specifications, or modify it according to desired specifications for gasoline performance. To do that, the user types in a new value for a property desired to be changed and presses a “Save Data” button at the bottom of the page. Once the user has saved the modified specifications, it will be automatically added to the list of custom blends below the predefined list of original products.
Once the user has defined characteristics of the desired final product(s), the user selects gasoline components whose combination might meet the target product specification and produce the required volume of this product at the lowest possible cost. The negotiation operation (discussed above) allows the user to select from a wide variety of gasoline components available in the market and to see the current pricing information for each of them. The user enters the desired minimum and maximum quantity and price for each added component. Once he has finished defining the components, CBAT-G evaluates the components to determine the optimal combination of gasoline components.
While evaluating the optimal combination of gasoline components, CBAT-G considers the availability and price of the optional product, compares it to the same parameters of the required components, and decides whether or not it should be used for blending. An optional parameter tells CBAT-G that the minimum volume specified is a lower threshold limit. This means CBAT-G will choose the best solution for either zero or between the minimum and maximum allowed but not between zero and the minimum. If the optional component is used for blending, the volume will be greater than the minimum amount mentioned. If the option parameter is not used, CBAT-G will use at least the minimum quantity of each added component.
Depending on whether or not the user has any gasoline components on hand, he may start the evaluation or continue the selection process. If he decides to use the gasoline components he already has in stock, he proceeds to the In-Stock or On-Hand Components view. Otherwise, he presses the Evaluate button to start the data analysis.
Once CBAT-G completes the analysis of data, it displays the Result page (see FIG. 13 b ). While evaluating the combination of existing gasoline blend components, CBAT-G tries to find a feasible and optimal solution for the most cost-effective gasoline blend that will meet the target gasoline specifications and yields desired by the processing refinery. In one example, after having analyzed all possible combinations of the selected gasoline blend components, CBAT-G chose the most cost-effective combination of the Negotiation Center MTBE, Normal Butane, Lt Alkylate and Russian Naphtha to produce the desired volume of Colonial PL Conv 93. The target product is checked to determine if it meets the desired specification requirements. The specification page for the Colonial P/L Conv 93gasoline will appear. The top portion of the specification page indicates the proportion of each blending component in the finished product. The lower part of the specification page shows blended products of the finished product that meet all specification requirements, with the API Gravity, Research Octane, Motor Octane, Benzene and other properties values falling between the lower and upper bounds imposed by the processing refinery. The user clicks the Save Data button to save the final product specification to their local system.
The Component Blending and Trading—Diesel (CBAT-D) tool helps the trader to choose the type and quantity of each available blendstock needed to produce the desired volume of specific grades of diesel oil.
By way of overview, the purpose of distillate blending is to manufacture a variety of products including various grades of diesel oil and kerosene, jet fuel oil, and gas oil. The actual production of the amounts of specific products fluctuates within limited parameters, based on seasonal demands or economic market situation. During the blending process, various refinery streams are mixed together to create finished products that should conform to the refinery product specification and meet local regulatory and economic requirements in different geographical locations.
The CBAT-D tool enables the user to: evaluate feasibility and cost-effectiveness of specific blendstocks available in the market, find the optimal way to acquire or dispose of blend components to meet the company current and planned business needs and maximize the profit margins and rapidly estimate the potential value of finished products based on blending components specifications.
Employing CBAT-D, the user selects the name of the required distillate blend from a Blend Specifications table. The user may select as many products as he likes, depending on how many distillate blends he wants to produce, but he can add only one product at a time. Before beginning to enter the quantity and price information for the desired distillate product(s), the user may view and modify the specification for the selected product. The specification is set by the ASTM and lists basic properties of the selected jet fuel, such as API gravity, Sulfur Content, Flash Point, Freezing Point, Smoke Point, Pour Point, etc. The CBAT-D functionality enables the user to create a new product specification by modifying the existing specification properties as viewed in a separate working window.
Changing the specification does not modify the underlying database entry. The saved specification will only be available to the author of the specification. Once the user has saved the modified product specification, it will be automatically added to the list of custom blends below the predefined list of original products.
Once the user has defined characteristics of the desired final product(s), he selects blend components whose combination will meet the final product specification and produce the required volume of this product at the lowest cost. The deal negotiation screen views 41 , 43 and above discussed functionality allows the user to select from a wide variety of distillate components available in the market and to see the current pricing information for each of them.
Depending on whether the plan is to use any Distillate components in stock for blending, the evaluation may be started or the selection process may continue.
To choose certain amounts of in stock components for blending with components selected from the deal negotiation system: the user selects the desired distillate blendstock from the In-Stock or On-Hand Components view, selects the desired blending date from the dropdown list box, enters the name of the destination place for the product delivery, presses the Add button at the bottom of the screen to move the selected component into the table, closes the dialog box, enters the maximum quantity he wants to use and the cost of the component, checks the Optional checkbox if needed and finally presses the Evaluate button to start the data analysis.
Once CBAT-D completes the analysis of data the user has entered, it displays the Result page similar to the one shown in FIG. 6 . While evaluating the combination of selected distillate components, CBAT-D tries to find the optimal solution for the most feasible and cost-effective distillate blend that will meet the target product specifications and yields desired by the processing refinery.
In one example, after having analyzed all possible combinations of the selected blend components, CBAT-D chose the most cost-effective combination of the deal negotiation system HT Kerosene and Straight-run Kerosene to produce the desired volume of Jet Fuel. To make sure that the final product meets the specification requirements, a user clicks on the downward arrow in the Resultant Product Blends page. The specification page for the Jet Fuel blend then appears. The upper portion of the specification page indicates the composition of the finished product (40% of HT Kerosene+60% of Straight-run Kerosene). The lower part of the specification page indicates that the target product meets all specification requirements, with the API Gravity, Sulfur content, Smoke Point and other properties values falling between the lower and upper bounds imposed by the processing refinery. To user saves the final product specification to their local system, by clicking the Save Data button.
The Component Blending and Trading—Fuel (CBAT-F) tool helps the trader to choose the type and quantity of each available blendstock needed to produce the desired volume of specific grades of fuel oil. The purpose of Fuel Oil Blending is to manufacture a variety of products including various grades of bunker oil, furnace oil and heating oil.
By way of background, during the blending process, various refinery streams are mixed together to make a finished fuel oil product with specific qualities and characteristics. Typically, a refinery uses its own raw materials, but sometimes a trader has to purchase blendstocks in the open market to produce a specific amount of the target product at the lowest cost. While evaluating various blendstocks to purchase, the trader should consider the following: the processing refinery's specification limits, seasonal demands (i.e., during the winter, a refinery produces more heating oil) and economic market situation (fluctuations in product prices and demand/supply balance).
The CBAT-F Tool enables the user to evaluate feasibility and cost-effectiveness of specific blendstocks available in the market and to rapidly estimate the potential value of finished products based on blending components specifications.
In the preferred embodiment, the CBAT-F tool is used to select the name of the required Fuel Oil blend from the Blend Specifications List Box in the Target Product table. A user elects as many products as desired, depending on how many fuel oil blends he wants to produce. To view the specification for the desired product, the user clicks on the downward arrow button to the right of the product name. The specification page will appear. The specification lists basic properties of the selected fuel oil, such as API gravity, Flash Point, Pour Point, Viscosity, etc.
To modify the product specification according to a user's own quality requirements, the user types in a new value for a property he wants to change and presses the Save Data button at the bottom of the page. The specification will be saved to the user's local system (note: changing the specification will not modify the underlying database). The saved specification will only be available to the author of the specification. Once the user has saved the modified specification, it will be automatically added to the list of custom blends below the predefined list of original products. To move it to the target view, the user clicks on the button to the right of the list.
Once the user has defined characteristics of the desired final product(s), he needs to select fuel oil blend components whose combination will meet the target product specification and produce the required volume of this product at the lowest cost. The deal negotiation screen views 41 , 43 functionality allows the user to select from a wide variety of fuel oil components available in the market and to see the current pricing information for each of them.
To select components using the negotiation operation, the user clicks on the Add button in the upper right comer of the view. The Select Component and Location dialog appears. The user selects the Fuel Oil component he wants to use for blending from the Components list box. The user select the desired blending date from the drop-down list box. He enters the name of the destination place for the product delivery into the Location box. He next presses the Add button at the bottom of the dialog to move the selected components to the Negotiation Center Components view. To close the dialog, the user presses the Close button. If the user wants to view and edit specs for the selected components, he clicks on the arrow button to the right of the component name. The user enters the desired minimum and maximum quantity and price for each added component. Once he has correctly defined all the selected components, the Evaluate button appears at the bottom of the screen allowing him to start the data analysis.
While evaluating the optimal combination of Fuel oil components, CBAT-F will consider the availability and price of the optional product, compare it to the same parameters of the required components, and decide whether or not it should be used for blending. The user checks the Optional checkbox if needed. Note that checking Optional tells CBAT-F that the minimum volume specified is a lower threshold limit. This means CBAT-F will choose the best solution for either zero or between the minimum and maximum allowed but not between zero and the minimum. If the optional component is used for blending, its volume will be greater that the minimum amount mentioned. If the user leaves the checkbox unchecked, CBAT will use at least the minimum quantity of each added component.
Depending on whether the user has any Fuel Oil components on hand, he may start the evaluation or continue the selection process. If the user decides to use the Fuel Oil components already in stock, he proceeds to the In-Stock or On-Hand Components view, otherwise, he presses the Evaluate button to start the data analysis (note: the Evaluate button appears at the bottom of the screen only if all necessary components are properly defined, if the definition was incomplete, the user will see an appropriate warning instead).
Once CBAT-F completes the analysis of data entered by the user, it displays the Result page similar to the one shown in FIG. 6 .
While evaluating the combination of existing fuel oil components, CBAT-F tries to find the optimal solution for the most feasible and cost-effective Fuel Oil blend that will meet the target product specifications and yields desired by the processing refinery.
In one example 700 bbl of fuel oil are required, after having analyzed all possible combinations of the selected blend components, CBAT-F chose 400 bbl of the optional Naphtha, 200 bbl of the required Heavy Oil Cracker Cycle Oil, and only 100 bbl of Heavy Oil Cracker Distillate that is the most costly of all components. The finished product meets the target product volume requirements (700 bbl) and maximizes the profit margin ($3800).
The foregoing decision support tools are executed as non-client computer resident processes as illustrated in FIG. 7 . Typically, a user on a client computer 25 ( FIG. 1 ) launches a browser program (e.g., a Web browser, such as Microsoft® Internet Explorer). The browser program accepts a Uniform Resource Identifier (URI) as a target address (e.g., www.petrovantage.com\lp-models) for a host computer 27 ( FIG. 1 ). The host computer 27 manages and executes linear programs to provide analysis of a specific aspect of petroleum trading, refining or logistics. Hosting the decision support tools 39 on a non-client computer 27 avoids problems associated with specific client computer 25 installations and provides for improved maintenance situations. Providing the decision support tools 39 on an Internet-connected host 27 allows users access from any Internet-connected client computer 25 with effectively unlimited availability.
A conventional linear program for running petroleum trading, refining or logistics models is Aspen PIMS. The models requires various inputs that are typically supplied through an input spreadsheet (e.g., Microsoft® Excel) read by the linear program. Embodiments of the present invention replace the spreadsheet input mechanism with a series of graphical user interface screens that allow the user to enter input data in real-time about the specific petroleum trading, refining or logistics problem as described above for the CBAT, COBAT and COE tools. Additionally, embodiments of the present invention can receive input data about the specific petroleum trading, refining or logistics problem as a programming object (e.g., trade object 67 ).
Conditioning of the various inputs to the linear programming models allows for improved reliability. Conditioning involves placing the various inputs in better order for processing and can include format and units of measure conversions (e.g., API v. specific gravity).
Analysis of a particular petroleum trading, refining or logistics problem includes receiving the input data describing the problem to be solved. This data is conditioned such that the linear program operates most effectively. Additionally, certain equations that make up the linear programming model are modified to account for the fact that multiple instances of the linear program may be executing. In particular, known unreliable paths of existing linear programming models are avoided, or minimized, in the equations that form embodiments of the present invention. The modifications provide for increased stability in a multi-instance environment.
Management of the linear programming model on a host computer 27 involves a cycle of launch/execute, check status and close. Multiple instances of the linear programming model can be running simultaneously. The host computer 27 periodically checks the status by “pinging” a specific instance. In the preferred embodiment, status checking/pinging occurs every three seconds. Pinging is a non-resource intensive operation directed at an instance to determine whether it is still executing (i.e., not hung). An executing instance will respond to a ping. This allows the host computer 27 to clean-up instances that have “hung” (i.e., are no longer responding to a ping). An example of a system that supports pinging is the Microsoft® Component Object Model (COM) system.
Output from the linear programming analysis is packaged using standard Internet protocols for display (e.g., HTML or XML with Cascading Style Sheets). The output is sent over the network 23 using standard HTTP communication standards. This output mechanism allows a standard Web browser to display the output from the linear programming analysis, where conventional systems typically produce output as a spreadsheet-formatted or database-formatted file.
The combination of Internet access to a non-client computer resident linear programming model (included as part of software program 31 ), use of HTML protocol for reporting, use of HTTP protocol for communication, providing stability through variable/equation conditioning and real-time access provides a much improved user experience for analysis of petroleum trading, refining or logistics problems. Further tools are available in the preferred embodiment of deal negotiation system 37 a . For instance, the arbitrage analyzer tool is designed for refinery supply traders, trade houses, cash brokers, ship brokers, producers/marketers, and the like, enabling them to automatically monitor and analyze fluctuations in the economics of crude oils and refined products. The tool continuously monitors the changing market opportunities, including cross commodity prices and freight-arbitrage relationships, in order to evaluate margin opportunities (e.g., FOB versus CIF decisions). Additionally, users can quickly respond to short notice market opportunities and make timely decisions to capture the advantageous yields versus cost opportunities.
FIG. 6 a is a block diagram of an arbitrage analyzer 310 configured according to an embodiment of the present invention. An arbitrage relationship is defined as having two elements (offerings) that will be adjusted and compared in order to determine if a predefined spread has been triggered.
In a preferred embodiment of the present invention elements A 312 and B 314 define two elements of an arbitrage relationship. Adjustments are made to the elements A 312 and B 314 using functions f 1 318 and f 2 320 , respectively. These adjustments allow for more effective comparisons. Functions f 1 318 and f 2 320 take inputs X 1 316 and X 2 322 in order to produce outputs. The difference between adjusted elements A 312 and B 314 is compared (e.g., less than, greater than or equal to) to a predefined spread, S 324 , by arbitrage function 326 to determine if a trigger, T 328 , should be activated.
In the simplest case f 1 318 and f 2 320 are the identify function and elements A 312 and B 314 are processed through the arbitrage analyzer unadjusted. In more interesting cases, elements A 312 and B 314 are adjusted using algorithms and internal and external data to condition those elements for comparison. Inputs X 1 316 and X 2 322 need not be simple scalar values, these inputs can be the results of economic evaluation tools (e.g., COE-R) or blending analysis tools (e.g., COBAT), described above.
In one example element A 312 represents an available crude oil in one part of the world (e.g., Brent crude) while element B 314 represents an available crude in another part of the world (e.g., West Texas Intermediate). Functions f 1 318 and f 2 320 act on elements A 312 and B 314 using data X 1 316 and X 2 322 . This data will typically include the commodity (crude) price. Additionally the present invention will factor in other external data elements such as freight options/costs, financing options/costs, contract and delivery times, storage options/costs, the time value of money, and the like. The results of all the adjustments are normalized into a price for each arbitrage element. For example, the Brent price might come out to $34 per barrel, whereas the West Texas Intermediate price might come out to $35 per barrel. A trigger T 328 can be set to detect when the price per barrel of these two commodities differ by more than $1 per barrel. The triggers can be visual, audible and/or activated to execute another processes (e.g., a messaging or electronic mail system).
This “geographical arbitrage” is only one example of the types of arbitrage analysis available in the present invention. The arbitrage elements can represent crude oil, intermediate feedstocks and/or petroleum products. Arbitrage relationships do not necessarily have to be defined on identical element types (e.g., crude v. crude, or product v. product). Interesting arbitrage relationships can be defined on dissimilar elements (e.g., Brent crude v. U.S. unleaded gasoline).
In another preferred embodiment a user-interactive graphical user interface (GUI) is provided to define trader specific arbitrage views (e.g., Brent crude v. West Texas Intermediate). The GUI allows a user to select a specific region of the world (e.g., by clicking on an interactive computer map) and view a list of posted crude oil prices from online pricing feeds, such as Reuters or Platts. The use can choose a desired crude oil and select another crude oil to make up an arbitrage relationship. Graphically this is accomplished by using interactive graphic tools to draw a line (i.e., define an arbitrage relationship) between two geographical regions and selecting specific crude oil products. Once an arbitrage relationship is defined a graph based on the associated data from the online pricing feeds is produced. The graph provides a visual comparison of price differences between the crude oils that make up the defined arbitrage relationship. Alarms and triggers may also be set execute when the price differential reaches, exceeds, or drops below a predefined limit. Alarms and triggers can be audible, visual or based in other mediums.
FIG. 6 b illustrates a graphical user interface for defining and viewing an arbitrage relationship configured according to a preferred embodiment of the present invention. A world map 131 is displayed in order to focus the user's selection of a particular crude oil on a specific geographic region (e.g., the North Sea v. Texas). The user invokes (e.g., by right-clicking a mouse button) the selection tool 130 to display a list of available crude oil for that geographic region. For example, when the selection tool 130 is invoked over the North Sea are off the coast of the United Kingdom, North Sea 1, Brent and North Sea 2 crude oils are displayed. The geographic region boundaries are preset, and re-configurable. Selection tool 130 allows a user to select an available crude oil and using a pointing device (e.g., a mouse), to draw a line 132 to another geographic region of the world represented on the world map 131 . Once the line 132 is drawn the selection tool 130 is invoked for the end-point of the line 132 . For example, if the end-point is located near Texas, US, the selection tool 130 can display West Texas Intermediate (WTI), East Texas Intermediate (ETI) and South Texas Intermediate (STI). The user now selects an additional available crude oil to define an arbitrage relationship. An arbitrage charting tool displays an arbitrage chart 133 that shows the difference in per barrel price of each of the selected crude oils over a predefined time. The arbitrage analyzer tool allows a trader to visualize differentiations among arbitrage relationship elements.
Embodiments of the present invention provide petroleum trading, refining and logistics aware search engines. These specialized search engines recognize attributes associated specifically with petroleum trading and logistics. The search engines contain search-library knowledge bases which define attributes for a specific domain (e.g., petroleum trading and logistics). These attributes provide enhanced navigation of petroleum-based or logistics-based Web sites or other data stores. The petroleum aware search engines can be configured to navigate a specific Web site (e.g., a user's internal Web site) or they can be configured to crawl over a series of external Web sites.
For example, a trader may be “looking for a deal on Brent crude”. The domain aware search engine will recognize that this query is a crude oil trade query and associate specific attributes from the search-library knowledge base with it. In this case, the commodity type, location, price and availability dates attributes will be used to search for records, pages or other storage elements that relate to “a deal on Brent crude”. Each record, page or other storage element found will display values for commodity type, location, price and availability dates attributes.
Refinery supply planners periodically create refinery supply plans. These plans typically model the supply needs and expected output of a specific refinery for a specific period of time (e.g., monthly). In conventional systems these plans are not adjusted until the next planning period. Using the domain aware search engine of the present invention refinery supply planners can encode searching requirements to uncover economic, logistic or other interesting developments in supply elements (e.g., a price drop in the Brent crude used as input to a refinery) or output elements (e.g., gas price increase 20 cents/gallon). The automated detection of these external changes allows a refinery supply planner to modify his plan on a weekly, daily or almost continuous basis to achieve the highest possible margins for his refinery.
The domain aware search engine can be configured to search various types of data sources, including Web pages and networked databases. In one preferred embodiment the domain aware search engine can search deal negotiation system 37 a . Alternate data sources include published market price provides (e.g., Platts, NYMEX), internal customer price/availability forecasts as well as private market maker Web sites (e.g., EnronOnline.com) and public markets (e.g., HoustonStreet.com, RedMeteor.com). The markets providers may or may not be in a partnership relationship with the searcher.
FIG. 6 c illustrates a petroleum trading, refining and logistics aware search engine configured according an embodiment of the present invention. A series of server computers 143 , 144 , 145 are connected to a network 146 . Each server computer 143 , 144 , 145 may contain searchable content. A domain-aware search engine 141 executes on client computer 140 and searches on computers connected to network 146 for content using domain specific knowledge stored in search library knowledge base 142 .
Transport selection and optimization tools enable the petroleum trader to screen and select available fleets, vessels, barges and pipeline cycles for the transportation of specific cargos and to evaluate the most economical way to deliver a product to its final destination.
With regard to vessel scheduling application 37 b ( FIG. 2 ), bulletin board technology is employed. The vessel scheduling bulletin board enables brokers and vessel owners to post available dates and times for transportation by subject vessel. In a preferred embodiment, the postings are supported by the data stored in vessel objects 81 ( FIG. 4 b ). The vessel name and owner name may initially remain anonymous. A unique identifier (vessel ID) and class (from a predefined class type) sufficiently identify the vessel and capacity. In addition to on-line browsing of the bulletin board of available vessels, scheduling application 37 b provides a search function or operation. The search function searches for available vessels given a specified load/quantity, location and delivery dates of a subject petroleum commodity. The user can add specific filtering ‘rules’ to refine the search to include company specific operating philosophy (e.g., to select only double hulled vessels). For example, the “add to decision support tools” operation 54 downloads quantity, location and delivery date data of a user-selected deal 45 displayed in the deal negotiation system screens 41 , 43 . Scheduling application 37 b uses the downloaded data (e.g., trade object 67 ) as input to the search function. The search function compares the input quantity to load capacity of various classes of vessels and consequently identifies appropriate vessel classes for the subject deal 45 . Based on the identified vessel classes appropriate for the subject deal 45 , the search function looks at schedules and waterway restrictions of specific vessels of that identified class. The search function compares the input delivery dates to the schedules of the vessels ( FIG. 4 b ) and determines available suitable vessels. The search function compares the input location to the waterway restrictions 91 of the identified and determined vessels and accordingly filters out the vessels that are restricted from the target (input) load/delivery locations. The remaining date-wise available vessels that meet the delivery port requirements are candidate vessels that the search function recommends on output.
Cost of each of the candidate vessels is calculated based on a completed voyage as determined by related market variables (load port to load port), capacity transported, clean/dirty status and cost rate found in respective vessel objects 81 ( FIG. 4 b ). The search function may also output respective transportation costs of each candidate vessel for the given deal 45 .
The deal negotiation system 37 a and other decision support tools 39 use the results of the scheduling application 37 b search function to generate a delivered commodity price. In particular, for a given trade deal 45 , the deal negotiation system 37 a sums the commodity price and transportation cost to form the delivered commodity price in arbitrage analyses and various deal negotiation system screen displays 33 (including the main deal negotiation view 41 and subscreen/tab views 43 ).
FIG. 12 is an illustration of a graphical user interface for vessel searching and optimization configured according to an embodiment of the present invention. Three panels are displayed. The Search for a Ship panel 260 provides an interface to specify search attributes for use in locating an available ship to carry a cargo. These attributes include: quantity and type of the cargo, port to/from information and various required attributes of the ship. The List of Ships that are Available panel 270 displays a list of ship that are available and meet the requirements of the search attributes defined in the Search for a Ship panel 260 . The name of the ship may not be displayed, or may be a pseudo-name, such that the actual name is not revealed until later in the contracting process. The List of Ships that are Available panel 270 display various ship specific attributes, including: World Scale Rate, last cargo and flag, among others. The List of Ships that are Available panel 270 allows a user to select one of the available ships and have it appear in the Select a Ship panel 280 . A ship in the Select a Ship panel 280 can be “put on subs” using the Put on Subject button 284 . Putting a ship “on subs” effectively holds a ship of a predetermined amount of time without committing to contract for it. The Notify button 286 informs the ship owner of a offer to contract for the ship. The owner's name may not be available to the user at this point.
The vessel scheduling application 37 b may be integrated with other decision support tools 39 (e.g., CBAT-G) to provide vessel scheduling support to a petroleum product trade deal 45 . FIG. 13 a illustrates the CBAT-G tool being used to evaluate (using Evaluate button 296 ) in stock or on hand components (displayed in the In Stock or On Hand Components panel 294 ) and components available for trading (displayed in Trade Floor Components panel 292 ). The blend specification of the desired resultant petroleum product is selected using the Blend Specification panel 290 .
FIG. 13 b illustrates a graphical user interface for displaying resultant petroleum product blends resulting from a CBAT-G evaluation. Resultant Product Blends panel 300 displays the blend specification and various related attributes, including: volume, cost per barrel and value of the resultant blend. The resultant In Stock or On Hand Components panel 304 now provides a Remove From Available Stock button 308 to affect the allocation of various components to the resultant product blend. The resultant Trade Floor Components panel 302 now provides a Make a Deal button 306 . Make a Deal button 306 launches a decision support tool that will provide access to vessel scheduling application 37 b such that the user can optimize his selection of vessel used to ship components of the resultant petroleum product blend, or the resultant petroleum product blend itself.
A collaborative workflow environment 200 ( FIG. 8 ) configured according to an embodiment of the present invention provides automation for routine business process standardization, reduces error rate and frees users to perform higher-level tasks. One key aspect of the collaborative workflow environment is the ability to communicate and transfer data among users performing roles in a collaborative workflow process. The Collaborative Workflow Environment (“CWE”) is an easy to use point and click way to automate work processes and collaborate with partners. It allows for customization of these processes/activities through a ‘builder’ interface which produces templates matching a business process flow. The templates are applied to the matching business condition/transaction and keeps track of the various activities for a customer. The Collaborative Workflow Process (“CWP”) allows for alarms, alerts, data sharing, discussion groups, and integration with internal and external systems reducing the cost of business and maximizing efficiency.) The collaborative workflow environment 200 can integrate with other systems (e.g., via workflow object) to provide integrated collaborative workflow. This enhances the coordination of team activities in both normal and upset situations. The collaborative workflow environment 200 also provides high visibility of end-to-end supply chain points.
The transient nature of many crude oil, intermediate feed stock and crude products deals requires an efficient mechanism for coordinating the many tasks associated with a trade deal 45 . Conventional methods of telephone communication and paper task tracking are costly and error prone. A method of providing automated workflow management would reduce the cost and increase the accuracy of conducting crude oil, intermediate feedstock or petroleum product trades.
During the lifecycle of a trade, four types of interactions are typically repeated again and again: (1) iterative work review and approval processes, such as working with the refinery planner and economist to produce the crude oil basket; (2) notifying other participants in planning, trading and logistics processes, such as confirming deals with the refinery scheduler, ship broker, storage and terminal operator and inspection surveying company; (3) tracking, aligning, or transferring work from one person or group to another, such as passing the deal sheet to the accounting and scheduling groups; and (4) transferring and transmitting data among different software systems, such as transferring data to back office and risk management systems.
The present invention collaborative workflow environment 200 allows user to deal rapidly with these activities, dramatically reducing the time and complexity necessary to coordinate the multiple resources required to close deals and arrange associated logistics. It also enables rapid response internally and from business partners to unexpected deviations and opportunities in supply chain logistics, commodity markets, or transportation markets.
In order to help customers establish the collaborative trading and logistics networks that make this goal a reality, the collaborative workflow environment 200 enables: (1) internal processes which are completely secure and internal to a company, such as coordinating trading with supply planning and scheduling; (2) private processes conducted between a company and its closest partners, such as managing long-term crude supply contracts and long-term ship charters; (3) public processes which are conducted in the general marketplace, such as the purchase of a large lot of gasoline or chartering of a vessel for a specific voyage.
In a preferred embodiment, the collaborative workflow environment 200 is delivered via role-based consoles, thereby increasing staff productivity by capturing the relationships between people, organizations, deals, and deadlines; and coordinating and synchronizing the work within and between companies. The collaborative workflow environment 200 can also automatically send notifications, route records for review and completion, and trigger the electronic transfer of pertinent data from the one business system to another (internal or external).
Supporting each console is a respective set of pre-configured collaborative workflow processes 210 (CWPs) which represent common work practices such as: close deal notification, close deal tracking, refinery upset, crude basket, ship late, pre-deal, product long/short, ship charter, inspection nomination and tanker lease inquiry are created as predefined templates. Additionally, client customized workflow processes can be defined. Once implemented, these workflow templates are modifiable to reflect specific needs and implement a company's own best practices.
Supply chain team members around the globe can work together economically in real time using the collaborative workflow environment. Changes in delivery schedules, upsets, or other unforeseen events are quickly broadcast to team members who can make contingency plans. Money and time are leveraged by circulating time-critical information quickly among integrated team members. Important milestones can be focused on without distraction. Ease of use puts all pieces of information at user's fingertips. Messages and alerts are displayed in the message center, flagged by their level of importance. Multiple collaborative work processes 200 (CWPs) can be active at the same time; the CWE console organizes them, sorts them, and flags them to the user. The provided set of templates, designed by leading industry experts, give system analysts a jumpstart on process design. Flexible architecture allows for the design of work processes to suit the company's requirements. Powerful messaging and discussion group features provide for the design of activities that reach out to every supply chain team member simultaneously. Links with the Deal negotiation application 37 a provides automated workflows that originate at trade deal 45 closing. Links with the decision support tools 39 allow inclusion of decision support analysis into a workflow. Links provide for launching internal processes that retrieve information to feed back into a workflow.
The collaborative work environment provides 200 a robust infrastructure that allows a user to establish and automate a company's work processes. A work process, known also as collaborative work process 210 , or CWP, is an automated and controlled flow of tasks performed by multiple participants. The tasks are linked together into a structured flow of work that can involve as many participants as the user defines and can consist of as many steps as needed. CWE's robust infrastructure allows business process experts and system analysts to design and automate workflows that link together people, deals, and deadlines to accomplish time-critical activities. The CWE 200 infrastructure contains the following key features: set of predefined workflow templates, a flexible architecture, messaging and discussion group features, links with the Deal negotiation application 37 a , links with the DSTs 39 . In one preferred embodiment these features are represented in a hierarchical structure of CWE 200 , CWP 210 , business processes 220 , 222 and activities 230 , 232 , 234 (see FIG. 7 ).
Each activity that comprises a CWP 210 is performed by the person responsible for its functions. Most activities 230 , 232 , 234 can have one and only one owner, discussion groups can have multiple owners. Since activities 230 , 232 , 234 can span all aspects of the industry, CWP 210 participants can be any of the following: contract administrators, credit managers, inspectors, ship brokers, terminal operators, pipeline operators, traders (e.g., crude traders, intermediate feedstock traders and refined product traders), schedulers (e.g., supply schedulers, crude refinery schedulers, products refinery schedulers, logistics schedulers), planners (e.g., refinery planners, refinery demand planners). CWE templates can specify individuals or roles as the initiator and/or responder. The roles will be resolved at run time allowing for easy maintenance as people with an organization changes job responsibilities. Typically, of course, a particular CWP 210 covers a set of work processes involving one segment of work, so its participants are those who perform that segment. For example, a refinery upset CWP would include a different set of participants, or roles (see FIG. 9 ) than the participants/roles involved in a Closed Deal Notification Message CWP (see FIG. 10 ).
Depending on a user's role in the organization, and their participation in one or more CWPs 210 , a user may work with CWE 200 in one or more ways. A user may be an initiator of an activity, the initiator is the owner of the activity, and therefore responsible for the successful and timely completion of the activity. An initiator will track their own activity, ensure that necessary responses are received, and send out necessary confirmations. An initiator may also track the other activities in their CWP 210 .
A respondent to an activity has the role of responding with the correct information within the allotted time-frame. This means that the respondent must keep an eye on the message center to watch for incoming messages. A respondent will also want to monitor the CWP 210 as a whole, to watch its progress and to be aware of any changes or delays.
Managers and other interested parties (i.e., “watchers”) will want to maintain an overview of CWPs 210 in progress at their site. They might filter the CWP 210 list to show only overdue CWPs 210 , so they know when action might be required.
The CWE 200 has its own console, the CWE view 240 , where a user can see a list of active CWPs 210 . In addition, CWE 200 uses many other panels to display the full set of features that make up a CWP 200 . In one preferred embodiment the CWE view 240 displays all the CWPs 210 in an organization each work process can be expanded to display its sub-processes (e.g., business processes 220 , 222 ) and activities (e.g., activities 230 , 232 , 234 ). The message center displays any messages that come to the user as part of a CWP. 210 . The instant message console displays real-time instant messaging discussions that come to the user as part of a CWP 210 . The time-line provides a linear, graphical view of the linked tasks contained in a CWP 210 , organized by date. The time-line shows task dependencies at a glance. The spider diagram shows relationships between CWP 210 work and players (persons performing roles).
The CWE view 240 ( FIG. 11 a ) displays the list of work processes in the CWE 200 as configured by the system administrator based upon which CWPs 210 are active at the present time. Each user logged into the CWE 200 can see all the work processes set up for his or her organization, but the list of CWPs 210 viewable may depend on the role associated with the user's login ID. FIG. 11 a shows a list of four active CWPs 210 for a planner. The list of CWPs 210 will change dynamically, throughout the day or even from hour to hour, depending on the CWPs 210 at the site and their status. Once all the activities in a CWP 210 are completed, the CWP 210 is moved to an archive.
List of CWPs 210 can be expanded to show more detail. Clicking on the plus (+) sign next to a CWP 210 in CWE view 240 expands it to display its business processes 220 , 222 and activities 230 , 232 , 234 . FIG. 11 b shows an expanded Closed Deal Notification CWP. This CWP sends out messages to key players once a deal is closed. Notifications to individuals can be configured in the builder, based on changes, past due status, or other milestones. A business process 220 , 222 is illustrated as Notification to Primary Party by System 250 . The business process has a beginning and end date. Two activities, Notify Internal Trader Team 252 and Notify Mid-Office System 254 are also illustrated (note: this CWP 210 has many more activities than are shown here). Each activity 230 , 232 , 234 is associated with an initiator and a respondent, and with beginning and end dates.
FIG. 11 c illustrates activity 230 , 232 , 234 details. Each activity listed in a CWP 210 is underlined, enabling the user to click on it and see its activity details dialog. The Activity Details dialog lists all the information contained in the activity as well as any documents attached by initiators or respondents. Activity data can be updated by users who have edit privileges and a change log will record the updates. Users who has reader access will see these updates when reviewing the activity.
While this invention has been particularly shown and described with references to preferred embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the scope of the invention encompassed by the appended claims.
Trading in petroelum-based products involves crude oil itself as well as many derivative products. For example, intermediate feed stocks are produced from crude oil and refined to produce petroleum products. Any final crude-based produce may be generally referred to as a petroleum product. The present invention considers a trade deal 45 to cover any crude-based product.
A vessel as used in reference to the present invention may be a ship, tanker, truck, airplane, or any other transportation container used to carry cargo.
The computer architecture of host server 27 may be distributed processing, parallel processing and the like. To that end a plurality of networked computers may form host server 27 . Certain data structures are disclosed as preferred embodiments, various other data structures besides definition tables 83 , 87 , 35 and programming objects 67 , 81 may be employed. | Currently lacking are effective and accurate tools to help petroleum traders and logistics personnel to make better decisions, collaborate in real-time and negotiate deals in a private and secure environment. The present invention addresses this and other needs in the industry.
In particular, the present invention provides a non-client computer resident method optimizes vessel scheduling by aggregating vessel information. At least some of the vessel information is automatically downloaded from an electronic source. The aggregated vessel information is stored in a vessel information database comprising vessel information database records. Information is obtained about a potential vessel contracting transaction. The vessel information database is searched in a real-time manner to match the potential vessel contracting transaction to at least one of the vessel information database records such that the vessel contracting transaction is optimized. At least one of the optimized vessel contracting transactions is then reported. Optimization factors used to produce the optimized vessel contracting transactions include lowest cost and fastest delivery. | 6 |
This application claims the benefit of U.S. provisional applications Nos. 60/247,184 filed Nov. 9, 2000 and 60/247,488 filed Nov. 8, 2000 both incorporated herein by reference in their entirety.
Reference to Government Funding
This invention was made with Government support under Contract Number N66001-00-C-8001 awarded by Space and Naval Warfare Systems Center. The Government has certain rights in this invention.
FIELD OF THE INVENTION
The field of the invention is secure groupware management.
BACKGROUND OF THE INVENTION
A virtual private network (VPN) is an overlay network that provides secure communication channels through an underlying (usually public) network infrastructure (such as the Internet), as a relatively inexpensive alternative to private secure lines. Communications among the members of a VPN are typically automatically encrypted using secure keys known to the members of the group, as a means of achieving the desired privacy for the members.
The management of encrypted group communications entails burdens such as the establishment, maintenance, and distribution of encryption keys. For example, in some systems, all members of a particular VPN may utilize a single global encryption key for private communication with other group members. In such systems, removing a member from the VPN typically requires the group manager to revoke the old key and to distribute a new group key to all members, so that the removed member can no longer decrypt private group communications. In addition, a VPN application may require individual members or various combinations of members to use different keys for particular interactions. In such an application there is an even greater key management burden. Generally, as the number of members increases, and as membership changes dynamically with greater frequency, the complexity of the management burden increases. Thus, very large and/or dynamic VPNs can cause overloading of the group manager, that represents a potential single point-of-failure, and consequently traditional VPNs may be considered relatively non-scalable. As large, distributed enterprises and organizations in our society rely increasingly on secure and private electronic communication and interaction, the need for highly scalable VPN architecture grows ever more pronounced.
FIG. 1 is a schematic of a prior art system where VPN 110 is managed by master node 120 . Prior art system VPN 110 is a typical simple-VPN. Communications among member nodes 130 a-c in VPN 110 are automatically encrypted using keys known to the appropriate group members, such that even though the communications are typically transmitted via the ordinary underlying public network infrastructure (e.g., the Internet), a “virtual” private channel may be effectively provided for group communications.
In a prior art system such as shown in FIG. 1 , master node 120 is responsible for managing VPN 110 group membership by performing the functions associated with entry or exit to or from a group, such as authentication, as well as distribution and maintenance of the secure encryption keys for private communication. Master node 120 may simply be a service-providing node, or may be a member of the group who also serves as a group leader; see, e.g., the Enclaves™ system created by the assignee of the present invention and described in L. Gong, “Enclaves: Enabling Secure Collaboration Over the Internet,” published in Proceedings of the 6 th USENIX Security Symposium, pp. 149-159, San Jose, CA (July 1996). In some typical VPN systems, the master node makes sure that all member nodes have up-to-date knowledge of the group encryption key and the identity of all current VPN group members, so that client communication software and/or hardware for each member node 130 can automatically encrypt communications and interactions addressed to other group members using appropriate encryption keys. Thus, if a group member leaves or is removed from the VPN group, master node 120 must notify all active group members of the membership change; must revoke the old group encryption key and generate a new one; and must provide the new key to all current members. Similarly, if a new node joins the group as a member, master node 120 usually notifies all active group members of the membership change. As noted previously in the “Background” section, this imposes a management burden on master node 120 , resulting in scalability problems and limitations for large, dynamic, and other VPNs.
SUMMARY OF THE INVENTION
The present invention provides a groupware management system that is scalable to include large, dynamic, and even multiple virtual VPNs. Scalability may be improved by introducing a graph (or hierarchical) structure to the VPN, thereby providing multiple master nodes controlling membership to the collaborative group.
In an aspect of the subject matter, multiple master nodes, each controlling a subset of the members, need only communicate with the subset of the member nodes for which it is directly responsible. Therefore, the communication and management burden on any given master node is preferably reduced relative to what it would have been in a single-master implementation.
A distributed approach tends to lead to a collaborative group that is relatively more scalable in terms of number of member nodes, dynamic nature, the number of separate VPNs that may be managed by a given master node, and other variables.
Some embodiments of the present invention include a group management system for use with a communications network. The group management system may have multiple interconnected nodes communicating with each other via the network as members of a VPN. A first master node preferably controls membership in the VPN of a first subset of the members, and a second master node, different from the first master node, preferably controls membership in the VPN of a second subset of the member nodes. Similarly, additional master nodes may each control VPN membership for an associated subset of member nodes. Use of multiple master nodes in a graph-structured (or hierarchical) manner relaxes the need for a single, centralized, globally consistent view of the group membership of the VPN. Not requiring a globally consistent view of the group membership generally enables distribution of the management burden among multiple master nodes. Membership in the VPN may be changed dynamically by the second master node for the member nodes of the second subset, without requiring the first master node to dynamically update its group membership records to reflect the change and in many cases without even having to notify the first master node (and vice versa), for example.
In an embodiment, the use of multiple master nodes communicating with each other may increase the reliability and efficiency of VPNs, such as by enabling load balancing of master node tasks. Fail-over mechanisms may also be used to transparently re-route management tasks to an alternate master node in the case of failure of the current master node serving a given member node.
In another embodiment, master nodes may provide remote installation of software communication mechanisms for a new member node. Efficiency may be further increased when the master nodes operate as components of an edge-based content delivery server network. Due to the relative proximity of edge network server nodes to member nodes, the use of an edge network usually provides more reliable connectivity between master nodes and member nodes, at higher speed, with lower latency and jitter, and generally allows for a broader geographic distribution of the master nodes.
Some embodiments may employ a viral construction of VPNs in a peer-to-peer network, and/or graph structured VPN topologies, including for example, multiple paths within the virtual overlay network between particular master nodes and member nodes. Such topologies may offer intrusion detection, improved fault tolerance, and other beneficial capabilities.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 schematically represents a prior art group management system.
FIG. 2 schematically represents a VPN management system having two or more master nodes.
FIG. 3 is a flow diagram illustrating a management method for joining a multi-master VPN.
FIG. 4 is a flow diagram illustrating a management method for leaving a multi-master VPN.
FIG. 5 schematically represents a system architecture in which group management responsibilities for a plurality of VPN groups are distributed and shared among multiple master nodes.
FIG. 6 schematically represents a multi-master VPN having a complex graph structure.
DETAILED DESCRIPTION
Network Definitions
A network “node” may be any type of device or collection of devices capable of processing instructions including (but not limited to) a cellular phone, a PDA, an intelligent household appliance, a general-purpose computer, a network server, a multi-processor cluster of computers, and a computer network such as a LAN. Network nodes are considered “interconnected” if there is a path for communication between them including a potential path, regardless of whether that path is direct.
A “simple-VPN” may be viewed as a collection of nodes that are interconnected in a secure manner. A simple-VPN is typically a communications group - that is, a simple-VPN generally enables every member node to transparently send private communications to other member nodes. A simple-VPN may employ a single encryption domain, i.e. a single encryption key is utilized for communications among all member nodes. The key may change over time, advantageously providing only one key is considered active for group communications within the VPN at any time. Simple-VPNs may consist of a master node and member nodes. The master node may be responsible for key management and group membership. A simple-VPN master node may also be a member node of the simple-VPN, and further, a single node may be a master node for more than one simple-VPN.
A “super-VPN”, as described herein, is an extension of the simple-VPN in which there may be standard simple-VPN member nodes, and further member nodes. In certain aspects, each of the further member nodes may be the master node of one or more other simple-VPN or (recursively) a master node of one or more other super-VPN. A super-VPN can thus be represented by a graph structure of simple-VPNs, or in a simple case, a hierarchy of simple-VPNs. A super-VPN generally comprises a single communication group—that is, every member node of the super-VPN may transparently send private communications to other member nodes. The super-VPN also may comprise one or more encryption domains. In the case of multiple encryption domains within a single super-VPN, inter-domain encryption translation becomes one of the group management tasks to be performed, preferably by the master nodes.
Distributed Management in a Super-VPN, with Dynamic Group Membership
The prior art described with reference to FIG. 1 corresponds to a simple-VPN in our terminology, and consists of a single encryption domain, or a collection of encryption domains, that utilize a single master node to mediate and manage all group communications.
A more scalable super-VPN architecture, especially suitable for highly dynamic VPN groups, is employed by a preferred embodiment of the present invention. This architecture and methodology may provide the same secure group communications functionality as the traditional VPN with lower overall management overhead, by distributing responsibility for managing VPN membership among at least two or more master nodes, each of which is assigned responsibility for a subset of the member nodes.
FIG. 2 depicts a super-VPN 200 , containing the master node 240 of the simple-VPN 230 as a member. This creates a hierarchical structure in super-VPN 200 whereby the management burden for controlling member nodes 250 a - c is delegated to master node 240 , as each master node manages and maintains its own membership list. Thus, the first master node 210 manages a member list including nodes 220 a - c and the second master node 240 manages a member list including nodes 250 a - c.
Some of the advantages of the super-VPN may be better appreciated if one considers the procedures typically entailed in joining or leaving a VPN. In a traditional VPN, as described above, all communications involving member nodes joining or leaving the VPN are typically directed to the single, over-worked, master node. In a super-VPN, these communications may instead be distributed over a plurality of master nodes. It is further contemplated that communications may be load-balanced among the master nodes using standard techniques of the network load balancing art.
FIG. 3 depicts a process for joining the super-VPN in one embodiment of the present invention. At step 300 , a node wishing to join a super-VPN locates a master node of the system. This may be performed using network resource discovery methods such as described in the present assignee's co-pending patent application Ser. No. PCT/US00/29290, “Resource Distribution and Addressing” (the “NEVRLATE” methods), or by any other suitable resource location method. The overall system of network master nodes may, in some embodiments, service and support more than one VPN communication group, and so in principle the first located master node may not necessarily currently manage membership for the particular VPN that the prospective member node wishes to join. Therefore, in some embodiments and as shown in FIG. 3 , at step 310 the first master node locates a second master node that is currently responsible and accepting enrollment for the requested super-VPN. The search for an appropriate second master node may similarly be accomplished using NEVRLATE or by any other suitable resource location method, just as for location of the first master node. In other embodiments, the initial query used at step 300 to locate a master node includes an identifier of the requested super-VPN, such that a currently participating master node is returned to the prospective member node making the query. In such embodiments step 310 is unnecessary and the flow of control proceeds directly from step 300 to step 320 .
Once the appropriate managing master node is located, at step 320 the master node authenticates the prospective member node. Assuming authentication is successful, at step 330 the master node preferably assesses whether to add the prospective member node to an existing encryption domain, or whether it would be better to create a new encryption domain for the new member. For example, as will be discussed further below in connection with FIG. 4 , practitioners may design the master node to assess and optimize the tradeoff between the additional work required to translate information flowing among additional encryption domains, versus the potential work associated with re-keying all members of a given encryption domain each time any current member of that domain leaves. Depending on the outcome of that assessment, the master node may add the new member to an existing encryption domain at step 340 , or initiate creation of a new encryption domain at step 335 . The master node may then add the new member node to said new domain at step 340 . In other embodiments, assessment element step 330 may be omitted and the master node may simply proceed directly from authentication at step 320 to adding the new member node as a client at step 340 within one of the encryption domains of the super-VPN currently managed by the master node.
In some embodiments, at step 350 the master node may provide remote online installation of software for VPN group communication mechanisms (encryption, etc.) for the new member node, obviating or reducing the need for local manual installation of such mechanisms by end-users. For example, the “Enclaves” technology referenced earlier herein includes relatively lightweight software modules implementing such mechanisms, or practitioners may readily create their own. In accordance with the teachings herein, a super-VPN master node may remotely install such software on behalf of its new member client nodes.
Step 360 , assigning a backup-master node, is employed in some embodiments as discussed below under the heading “Failure Tolerance in Super-VPNs”.
FIG. 4 describes a process of leaving a super-VPN. At step 400 , the member node intending to leave the super-VPN transmits notification of such intent to its assigned master node. At step 410 , the notification is authenticated as genuine to avoid the potential for unauthorized third-party nodes to remove illicitly a member node from a super-VPN. Once the notification has been authenticated, at step 420 the member node is removed from group communication. At step 430 the encryption key currently in use by the former member's encryption domain is revoked, and at step 440 the remaining member nodes in that encryption domain are given new encryption keys for further group communications.
The re-keying process just described at 430 - 440 presents a tradeoff against performing decryption and re-encryption in order to transmit information between encryption domains. In other words, minimizing the number of different encryption domains for a given collection of VPN member nodes (i.e. increasing the number of member nodes allocated to each encryption domain) generally reduces workload on the master node(s) to perform inter-domain encryption translation, but may increase the amount of re-keying that is performed when a member node leaves. Conversely, increasing the number of different encryption domains for a given collection of VPN member nodes (i.e. decreasing the number of member nodes allocated to each encryption domain) may increase the workload of the master node(s) to perform encryption translation for inter-domain communications, but may decrease the amount of re-keying that is performed when a member node leaves.
As mentioned previously, in preferred embodiments the master node may gather statistics on the dynamic nature of each simple-VPN encryption domain, and dynamically adjust the size of encryption domains by utilizing decision making techniques (such as “MCDA”—Multi Criteria Decision Analysis) to minimize or reduce the workload on the master node. In any event, it should be noted that because the super-VPN architecture introduced herein typically allocates and distributes membership management tasks among multiple master nodes, the overall workload for each master node to perform re-keying and/or translation for its assigned member nodes and encryption domains may be significantly reduced relative to what is required for traditional, single-master, single encryption domain simple-VPNs.
Even in the worst case, each master node in a preferred embodiment need only be responsible for re-keying its assigned member nodes; in contrast, in a traditional simple-VPN architecture, the single master node typically re-keys all members of its VPN whenever any member node leaves the group.
At step 450 , it is determined whether the removal of the member node from the simple-VPN hosted by the assigned master node results in a “trivial” simple-VPN, i.e., one in which the assigned master node is the only surviving member. If so, then the surviving master node may cease to be a participant in the super-VPN, by recursively applying to the surviving master node the procedure for leaving described in connection with FIG. 4 . In particular, if the surviving master node has one or more super-master nodes (i.e. master nodes to whom the surviving master node is a member in a simple-VPN, within the structure of the super-VPN), then the surviving master node preferably sends notification at step 400 to its super-master nodes that it wishes to leave the super-VPN, etc., with the entire process as described in connection with FIG. 4 being applied recursively. Said recursive application may eventually result in reducing the super-VPN to a trivial simple-VPN, in which case the super-VPN may cease to exist.
The use of multiple master nodes in a super-VPN in accordance with the teachings disclosed herein may thus increase the scalability of VPNs through distribution of encryption key management and other related tasks. Preferred super-VPN embodiments may similarly increase the reliability and efficiency of a VPN by enabling distribution and load balancing of other master node management tasks such as address management and validation of nonces. The latter (nonces) may be employed, for example, for purposes of the intrusion tolerance protocols disclosed In the PCT patent application entitled “Methods And Protocols For Intrusion-Tolerant Management Of Collaborative Network Groups, ” Ser. No. PCT/US01/1 3848, filed by the assignee of the present invention on even date with the present filing.
Failure Tolerance in Super-VPNs
In embodiments, fail-over mechanisms may be used to transparently re-route management tasks to an alternate master node in the case of a failure including failure of the current master node serving a given member node.
In a traditional VPN, failure of the single master node effectively disables the virtual secure communication channel among all of the individual member nodes of the VPN, and may therefore be considered a relatively catastrophic system failure. In the case of failure of a master node in a super-VPN, in contrast, what typically results is one or more super-VPN “islands”, meaning the super-VPN graph has been split into two or more disjoint sub-graphs due to the failure of a connecting master node.
When a super-VPN island is created, there may be no global knowledge of the group membership of a super-VPN, and some additional procedures may thus be necessary in order to re-establish complete group communication. One contemplated mechanism for re-establishing super-VPN group communications after the creation of islands, for example, relies on the assignment of a backup master node at step 360 of the process shown in FIG. 3 for joining a super-VPN. At step 360 , when a member node joins the super-VPN, the new node is preferably assigned and informed of a secondary (or “backup”) master node that may be contacted by the member node in the case of failure of its primary master node. In this event, the backup master node may perform the procedure outlined in steps 320 et seq. of FIG. 3 with respect to each of the member nodes isolated on the “island” for which the backup master is now responsible. This provides a mechanism for “island” recovery that can tolerate at least one super-VPN master fault, subject to the time required for re-joining the super-VPN at the secondary master node.
An embodiment involving island recovery includes the master node of the island super-VPN re-initiating the process described earlier in connection with FIG. 3 for joining the super-VPN, however treating the island VPN as a new prospective member node. Similarly, skilled practitioners may recognize other suitable systems and methods for re-establishing VPN group communication with respect to “island” nodes created in the wake of a master node failure.
Master Node Participation in Multiple VPNS; Edge Networks
In a further aspect, as shown in FIG. 5 , a given master node may have management responsibilities for two or more distinct super-VPNs and/or simple-VPNs. With reference to FIG. 5 , master node 500 has responsibility for member nodes 510 a - c belonging to super-VPN 520 , and master node 500 also has responsibility for members nodes 530 a - c belonging to simple-VPN 540 . Super-VPN 520 may further include master node 550 , with responsibility for member nodes 560 a - b . Although master node 500 often has responsibilities for both super-VPN 520 and simple-VPN 540 , the two VPNs typically represent two distinct communication groups; i.e., private communications within super-VPN 520 are not available to simple-VPN 540 , and vice versa. Membership and key management within simple-VPN 540 generally proceeds in the traditional manner, while membership and key management within super-VPN 520 are preferably handled in a distributed manner by master nodes 500 and 550 using the methods described earlier herein in connection with FIGS. 3 and 4 .
Master nodes 500 and 550 in FIG. 5 , for example, may be advantageously implemented and deployed as servers that are part of an edge-based content delivery network. Edge-based content delivery networks may be deployed to improve the speed, throughput, and so on of traffic flow through the Internet by using techniques such as the replication and caching of content (especially relatively static content) at so-called “edge” servers located around topological edges of the Internet. For example, when a client requests particular data content from a network source, this approach may automatically forward or re-route the client's request to an edge server where that content has previously been replicated or cached and that is positioned relatively close to the requesting client (or otherwise determined to have a good quality of connectivity with that client). The desired content is then preferably served to the client from that point, instead of having to traverse the interior “cloud” of the Internet all the way from an original, central server. Preferably the edge server is selected at least partly on the basis of performance criteria including best/closest connection to the requesting client. For example, selection criteria may preferably include connectivity estimates/metrics between the selected edge server and client system such as: geographical distance, topological distance, bandwidth, latency, jitter, financial costs (e.g. fees associated with any necessary traversals of commercial network backbone crossing points), and national/political boundaries that would be traversed. Note that edge-based content delivery network technology is known to skilled practitioners in the art, and has been widely commercialized by companies including Digital Island and Akamai. For more details see, for example, www.digisle.net, www.akamai.com; and U.S. Pat. No. 6,185,598 entitled “Optimized Network Resource Location.”
Due to the frequent proximity of edge network nodes to corresponding client nodes, implementing VPN master nodes as the servers of an edge network often provides more reliable connectivity between master nodes and member (client) nodes, usually at higher speed, with lower latency and jitter and may allow for a broader geographic distribution of the master nodes. These benefits are potentially available even in embodiments where the master nodes do not necessarily each manage multiple VPNs, as they do in the embodiment of FIG. 5 . However, the embodiment of FIG. 5 may further facilitate a business strategy whereby a managed network of server nodes, such as the edge-based servers of a content delivery network, can be exploited to provide services such as commercial hosting and management for relatively numerous concurrent simple and/or super-VPNs. The architecture shown in FIG. 5 may provide increased utilization and returns especially when employed for a given network of edge servers.
Super-VPN Graphs
It is contemplated that a member node of a first super-VPN may be the master node of one or more other super-VPNs or simple-VPNs. More generally, network configurations of arbitrary complexity may readily be implemented.
The earlier described FIG. 2 showed a super-VPN hierarchy of two master nodes. FIG. 6 further shows a super-VPN graph 600 containing the same number of nodes as FIG. 2 , but exemplifying how more complex arrangements of nodes may be constructed. In general, graph structures of arbitrary complexity may be designed and deployed by practitioners, as appropriate to various applications. Earlier, we described herein how the hierarchical structure of FIG. 2 allowed for the delegation of management burden from master node 210 to master node 240 . In embodiments with more complex graph structures such as shown in FIG. 6 , several aspects of reliability may be added to the super-VPN, as will now be discussed.
A difference between the super-VPN 200 of FIG. 2 and the super-VPN 600 of FIG. 6 is topology: super-VPN 600 provides multiple paths between any two member nodes, in contrast to the single path between any two nodes of super-VPN 200 . For example, a first path between member node 650 a and member node 620 a passes through both master nodes 640 and 610 , while a second path proceeds simply through master node 610 . Similarly, member nodes 650 a and 650 b are connected by three paths: one path proceeding through master 640 , a second path through master 610 , and a third path through both of the master nodes. In general, having N paths (where N>1) between two nodes enables the system to provide greater assurance that the group communications will reach every member node of the super-VPN, as the super-VPN can therefore tolerate the failure of N−1 paths between the two nodes. In addition to the fault-tolerance often exemplified by multiple paths between two nodes, a cyclic graph topology may provide a level of intrusion-detection in a super-VPN, i.e., detecting when a node in the super-VPN is not correctly forwarding messages but instead is modifying the content in some way prior to forwarding. The level of intrusion-detection may be achieved by comparing group communications that arrive at any given node having followed diverse paths from the communication's source node. A security advantage may be derived at the cost of relatively more network traffic being passed around overall (through the different paths), however, presenting a cost-benefit tradeoff for practitioners who may elect different decision choices for different applications.
Further contemplated super-VPN embodiments may utilize “peer-to-peer” networks. In contrast with a managed “edge network” deployment strategy, a characteristic feature generally is that no single authority has control over the nodes in the peer-to-peer network. Such deployments do not require any centrally managed build-up of infrastructure, and instead rely on “grass-roots” efforts to bootstrap the network infrastructure. Current examples of peer-to-peer networks include file/resource-sharing services like GNUtella. Embodiments are contemplated wherein master and member nodes of the super-VPN belong to a peer-to-peer network; essentially, a viral model of VPN deployment is adopted. Because the infrastructure nodes in peer-to-peer embodiments are typically unmanaged, in general there is no trust between any two nodes in the network. This may not be of paramount concern in some overlay applications; however, in the case of VPN services that require strict authentication and encryption, utilizing a viral peer-to-peer deployment may require extra security safeguards. Thus in peer-to-peer embodiments, the fault tolerance and intrusion-detection features described in connection with FIG. 6 may be especially beneficial.
Further Embodiments
Thus, specific embodiments and applications of groupware related methods and devices have been disclosed. It should be apparent, however, to those skilled in the art that many more modifications besides those described are possible without departing from the inventive concepts herein. For example, in a preferred embodiment, the master nodes control membership to a VPN, but it is contemplated that membership may be to a virtual overlay other than a VPN. For example, a master node may be controlling membership to a non-encrypted collaborative group communication or a multi-player game instead of a VPN. Such alternative applications may take advantage of the teachings herein for distributed and fault-tolerant group management (possibly still including the use of authentication of prospective member nodes) without the use of encrypted communications, and hence without the master nodes having to perform key management for the overlay network.
The inventive subject matter, therefore, is not to be restricted except in the spirit of the following claims. | A groupware management system for collaborative groups is disclosed that is scalable to support large, dynamic, multiple, and other virtual VPNs. The system may introduce a graph (or hierarchical) structure to the VPN, providing multiple master nodes controlling membership in subsets of the collaborative group. Use of multiple master nodes in a graph-structured (or hierarchical) network topology often relaxes the need for a single, centralized, globally consistent view of VPN group membership, and enables distribution of the management burden among multiple master nodes. Membership in the VPN may be changed dynamically by the second master node for the member nodes of the second subset, without requiring the first master node to dynamically update its group membership records to reflect the change and in many cases without even having to notify the first master node (and vice versa), for example. In further embodiments, the use of multiple master nodes may increase the reliability and efficiency of VPNs, such as by enabling load balancing of master node tasks. Fail-over mechanisms may also be used to transparently re-route management tasks to an alternate master node especially in the case of failure of the current master node serving a given member node. | 7 |
FIELD OF THE INVENTION
[0001] The disclosed invention relates to adsorbents for removing sulfur and sulfur compounds from liquid and gaseous hydrocarbon streams such as but not limited to gasoline, jet fuel, diesel fuel, naphtha, kerosene, gas oil, vacuum gas oil and cycle oil.
BACKGROUND OF THE INVENTION
[0002] Use of ultra deep desulfurization of liquid hydrocarbon fuels such as gasoline, diesel, and jet fuel to satisfy new environmental regulations and fuel cell applications is receiving increased attention worldwide. Conventional hydrodesulfurization (HDS) technology is difficult and costly to use to remove sulfur compounds from liquid hydrocarbon fuels to levels suitable for use in fuel cells, particularly for removal of refractory sulfur compounds such as 4,6-dimethyl-dibenzothiophene (4,6-DMDBT).
[0003] Several non-HDS-based desulfurization technologies for use with liquid fuels have been proposed. These technologies include adsorptive desulfurization biodesulfurization, oxidative desulfurization and extraction desulfurization.
[0004] Various desulfurization processes are known or have been proposed. For example, U.S. Pat. No. 3,063,936, issued on Nov. 13, 1962 to Pearce et al. discloses that sulfur reduction can be achieved for straight-run naphtha feedstocks from 357 ppmw to 10-26 ppmw levels by hydrotreating at 380° C. using an alumina-supported cobalt molybdate catalyst. According to Pearce et al., a similar degree of desulfurization may be achieved by passing the straight-run naphtha with or without hydrogen, over a contact material comprising zinc oxide, manganese oxide, or iron oxide at 350 to 450° C. Pearce et al. propose to increase sulfur removal by treating the straight run naphtha feeds in a three-stage process in which the hydrocarbon oil is treated with sulfuric acid in the first step, a hydrotreating process employing an alumina-supported cobalt molybdate catalyst is used in the second step, and an adsorption process, preferably using zinc oxide is used for removal of hydrogen sulfide formed in the hydrotreating step as the third step. The process is said to be suitable only for treating feedstocks that are substantially free from ethylenically or acetylenically unsaturated compounds. In particular, Pearce et al. disclose that the process is not suitable for treating feedstocks, such as hydrocarbons obtained as a result of thermal cracking processes that contain substantial amounts of ethylenically or acetylenically unsaturated compounds such as full-range FCC naphtha, which contains about 30% olefins.
[0005] A challenge in development of an effective adsorptive desulfurization process is development of an adsorbent which has high sulfur capacity, high selectively to the sulfur compounds over other aromatic and olefinic compounds coexisting in the fuels, and high regenerability and stability during recycle.
[0006] A need therefore exists for adsorbents which may be effectively used in adsorptive desulfurization processes.
SUMMARY OF INVENTION
[0007] In a first aspect, the disclosed invention relates to novel metal oxide-CeO 2 -based adsorbents of the formula MO—CeO 2 where M is any of Ag, Au, Ba, Be, Ca, Co, Cr, Cu, Fe, Ge, Hf, Ir, La, Mg, Mo, Ni, Os, Pb, Pd, Pt, Rh, Ru, Sc, Sn, Sr, Ti, W, Y 2 , Zr and mixtures thereof such as AgO—CeO 2 -based adsorbents such as Ag 0.1 Ce 0.9 O 2 , AuO—CeO 2 -based adsorbents such as Au 0.1 Ce 0.9 O 2 , BaO x —CeO 2 -based adsorbents where 1≦x≦2 such as Ba 0.1 Ce 0.9 O 2 , BeO x —CeO 2 -based adsorbents where 1≦x≦2 such as Be 0.1 Ce 0.9 O 2 , CaO—CeO 2 -based adsorbents such as Ca 0.1 Ce 0.9 O 2 , CoO—CeO 2 -based adsorbents such as Co 0.1 Ce 0.9 O 2 , CrO x —CeO 2 -based adsorbents where 1≦x≦3 such as Cr 0.1 Ce 0.9 O 2 , CuO—CeO 2 -based adsorbents such as Cu 0.1 Ce 0.9 O 2 , FeO—CeO 2 -based adsorbents such as Fe 0.1 Ce 0.9 O 2 , GeO x —CeO 2 -based adsorbents where 1≦x≦2 such as Ge 0.1 Ce 0.9 O 2 , HfO x —CeO 2 -based adsorbents where 1≦x≦2 such as Hf 0.1 Ce 0.9 O 2 , IrO 2 —CeO 2 -based adsorbents such as Ir 0.1 Ce 0.9 O 2 , La 2 O 3 —CeO 2 -based adsorbents such as La 0.1 Ce 0.9 O 2 , MgO x —CeO 2 -based adsorbents where 1≦x≦2 such as Mg 0.1 Ce 0.9 O 2 , MoO x —CeO 2 -based adsorbents where 1<x≦3 such as Mo 0.1 Ce 0.9 O 2 , NiO—CeO 2 -based adsorbents such as Ni 0.1 Ce 0.9 O 2 , OsO 2 —CeO 2 -based adsorbents such as Os 0.1 Ce 0.9 O 2 , PbO—CeO 2 -based adsorbents such as Pb 0.1 Ce 0.9 O 2 , PdO x —CeO 2 -based adsorbents where 0<x≦1 such as Pd 0.1 Ce 0.9 O 2 , PtO x —CeO 2 -based adsorbents where 0<x≦2 such as Pt 0.1 Ce 0.9 O 2 , RhO x —CeO 2 -based adsorbents where 0<x≦2 such as Rh 0.1 Ce 0.9 O 2 , RuO 2 —CeO 2 -based adsorbents such as Ru 0.1 Ce 0.9 O 2 , ScO—CeO 2 -based adsorbents such as Sc 0.1 Ce 0.9 O 2 , SnO x —CeO 2 -based adsorbents where 0<x≦2 such as Sn 0.1 Ce 0.9 O 2 , SrO—CeO 2 -based adsorbents such as Sr 0.1 Ce 0.9 O 2 , TiO 2 —CeO 2 -based adsorbents such as Ti x Ce y O 2 where 0<x/y≦1 and where 0<x≦1 and 0<y≦1 such as Ti 0.1 Ce 0.9 O 2 , Ti 0.5 Ce 0.5 O 2 , and Ti 0.9 Ce 0.1 O 2 , WO 3 —CeO 2 -based adsorbents such as W 0.1 Ce 0.9 O 2 , Y 2 O 3 —CeO 2 -based adsorbents such as Y 0.1 Ce 0.9 O 2 , and ZrO x —CeO 2 -based adsorbents where 0<x≦2 such as Zr 0.1 Ce 0.9 O 2 .
[0008] The novel adsorbents have high adsorptive selectivity and capacity for sulfur compounds in the presence of aromatics.
[0009] In a second aspect, the invention relates to the use of these novel adsorbents in, such as, devices such as fixed-bed type absorbers, fluidized-bed type absorbers, moving-bed type absorbers, and rotating type absorbers to remove sulfur and sulfur compounds such as thiols, disulfides, sulfides and thiophenic compounds from hydrocarbon streams such as hydrocarbon fuels, lubricant oils and hydrocarbon solvents and mixtures thereof, preferably hydrocarbon fuels such as gasoline, jet fuel, diesel fuel, naphtha, kerosene, gas oil and vacuum gas oil and mixtures thereof.
[0010] In this second aspect, a hydrocarbon stream contacts any one or more of the adsorbents over a temperature range of about 0° C. to about 100° C., preferably about 5° C. to about 70° C., more preferably at about 25° C., and at a pressure of about 0.05 MPa to about 0.20 MPa, preferably at about 0.10 MPa to about 0.15 MPa, more preferably at about atmospheric pressure, for a time sufficient to enable the adsorbent to adsorb sulfur and sulfur compounds such as thiols, disulfides, sulfides and thiophenic compounds and mixtures thereof, which may present in the hydrocarbon streams.
[0011] Use of these adsorbents to remove any one or more of sulfur and sulfur compounds from the hydrocarbon streams advantageously may be performed without hydrogen to produce clean liquid and gaseous hydrocarbon streams having less than about 1 ppmw sulfur to about 50 ppmw sulfur, typically about 10 ppmw sulfur or less, and clean hydrocarbon fuels having less than about 1 ppmw sulfur to about 50 ppmw sulfur, typically about 1 ppmw sulfur or less. The clean liquid and gaseous hydrocarbon streams may be used for fuel processing as well as directly in fuel cells.
[0012] The invention is further described in detail below by reference to the following detailed description and non-limiting examples.
DETAILED DESCRIPTION OF THE INVENTION
Method of Manufacture of Adsorbents
[0013] Generally, the novel adsorbents are made by mixing an aqueous solution of a cerium oxide precursor that has a concentration range of about 0.02 M to about 1.0 M, preferably about 0.05 M to about 0.5 M, more preferably about 0.10 M to about 0.20 M with an aqueous metal salt solution that has a concentration range of about 0.002 M to about 0.10 M, preferably about 0.005 M to about 0.05 M, more preferably about 0.01 M to about 0.02 M to form a first solution. Useful aqueous solutions of cerium oxide precursors include but are not limited to any one or more of ammonium cerium nitrate, cerium nitrate hexahydrate, cerium acetylacetonate hydrate, cerium sulfate hydrate, and mixtures thereof. Useful aqueous metal salt solutions include but are not limited to aqueous solutions of a metal oxide precursor such metal chlorite hydrates such as osmium chlorite hydrate, metal nitrate hydrates such as lanthanum nitrate hydrate, ferrous nitrate hydrate, cobalt nitrate hydrate, nickel nitrate hydrate, gold chloride hydrate and mixtures thereof, metal chlorides such as ruthenium chloride, iridium chloride, rhodium chloride, hafnium chloride, tin chloride, germanium chloride, platinum chloride, palladium chloride and mixtures thereof, metal nitrates such as lead nitrate, strontium nitrate, silver nitrate, barium nitrate, beryllium nitrate, calcium nitrate and mixtures thereof, chromium nitrate nonahydrate, ammonium molybdate tetrahydrate, magnesium nitrate hexahydrate, zirconyl nitrate titanium oxysulfate-sulfuric acid complex hydrate and mixtures of any one or more of the above.
[0014] The first solution is mixed with an aqueous urea solution that has a concentration range of about 10 M to about 0.1 M, preferably about 2.0 M to about 0.2 M, more preferably about 1.0 M to about 0.5 M to produce a mixed solution. The mixed solution is heated to form precipitates, and then cooled to room temperature to produce a cooled slurry solution. The cooled slurry solution is filtrated to generate precipitates which are heated to form dried precipitates. The dried precipitates then are calcined, such as at about 400° C. to about 600° C. in an oxidizing atmosphere such as air and to produce the adsorbent.
[0015] The adsorbents may include one or more oxidation catalysts such as Pt, Pd, V 2 O 5 , CuO, CrO x , Ag 2 O, MoO 3 , WO 3 , MnO, Nb 2 O 5 , CoO, Fe 2 O 5 , ZnO and NiO to accelerate oxidation of the adsorbed sulfur and sulfur compounds and to enable use of lower oxidation temperatures. The catalysts may be present in an amount of about 0.2 wt. % to about 25 wt. %, preferably about 0.5 wt. % to about 2.0 wt. %, based on the weight of the adsorbent. The oxidation catalysts may be incorporated into the adsorbent by loading the catalyst onto adsorbent by, such as, the incipient wetness impregnation method.
Method of Use of Adsorbents
[0016] In use, an influent liquid or gaseous hydrocarbon stream to be desulfurized is passed through a bed of adsorbent, such as a fixed bed of the adsorbent to produce a desulfurized hydrocarbon stream. A liquid hydrocarbon stream typically is passed at a temperature of about 0° C. to about 100° C., preferably about 5° C. to about 70° C., more preferably about 20° C. to about 30° C., even more preferably at about 25° C., and at a pressure of about 0.05 MPa to about 0.20 MPa, preferably about 0.10 MPa to about 0.15 MPa, more preferably at about atmospheric pressure. A gaseous influent hydrocarbon stream is passed at a temperature of about 0° C. to about 100° C. and at a pressure of about 0.1 MPa to about 5.0 MPa, preferably about 0.1 MPa to about 10 MPa. Typically, the adsorbent is at a temperature of about 0° C. to about 100° C. Adsorbent saturated with sulfur and sulfurized compounds may be regenerated and then reused.
Regeneration
[0017] Regeneration of the saturated adsorbent may be performed by passing an oxidizing agent, such an oxidizing gas or an oxidizing liquid, over the adsorbent. Oxidizing gases which may be used include air, ozone, N 2 O, O 2 -containing gas, N 2 O-containing gas or ozone-containing gas, or mixtures thereof. Oxidizing liquids which may be employed include H 2 O 2 , nitric acid, alkyl hydroperoxides such as tert-butyl hydroperoxide and cumene hydroperoxide, or mixtures thereof.
[0018] Oxidizing gases used for regeneration have an oxidizing gas partial pressure of about 5 v % to about 100 v %, preferably about 10 v % to about 90 v %, more preferably about 20 v % to about 80 v %. When an oxidizing gas or gases is passed through the adsorbent, the oxidizing gases are heated to about 100° C. to about 700° C., preferably about 200° C. to about 600° C., more preferably about 350° C. to about 600° C. The oxidizing gases are passed over the adsorbent for a time sufficient to achieve the regeneration, i.e., to remove about 90% or more of adsorbed sulfur and sulfur compounds from the adsorbent. This time is typically about 10 min to about 120 min. During regeneration, the adsorbed sulfur and sulfur compounds react with O 2 , or ozone or N 2 O to form SO x and CO 2 which leave the adsorbent. When oxidizing liquids are used, they typically are at a temperature of about 50° C. to about 300° C., preferably about 80° C. to about 250° C., more preferably about 80° C. to about 200° C. After oxidation by using oxidizing liquids, the adsorbent is dried under a flow of air, N 2 or oxygen-containing gas at about 100° C. to about 700° C., preferably about 200° C. to about 600° C., more preferably about 350° C. to about 500° C. After regeneration, the adsorbent is cooled to room temperature for use in a next cycle of adsorptive desulfurization of hydrocarbon streams.
[0019] The invention is further described below by reference to the following non-limiting examples.
EXAMPLE 1
Manufacture of La 0.1 Ce 0.9 O 2 Adsorbent
[0020] Urea in an amount of 35 g is placed in a glass beaker, and 800 ml deionized water is added to make 800 ml of 0.728 M aqueous urea solution.
[0021] 8.22 g of 99.99% pure ammonium cerium nitrate from Aldrich is dissolved in 100 ml deionized water to make 100 mL of 0.149 M ammonium cerium nitrate solution.
[0022] 0.8403 g of 99.99% pure lanthanum nitrate hydrate from Aldrich is dissolved in 100 ml deionized water to make 100 mL of 0.0259 M lanthanum nitrate solution.
[0023] 100 mL of the lanthanum nitrate hydrate complex solution is mixed with 100 mL of the ammonium cerium nitrate solution to form a first solution.
[0024] All of the first solution is mixed with 800 ml of the aqueous solution and vigorously mixed by magnetic stirrer to produce a mixed solution. The mixed solution is heated at 2° C./min to 90° C., maintained at 90° C. for 8 hours to produce precipitates, and then cooled at 10° C./min to room temperature to produce a cooled slurry solution.
[0025] The cooled slurry solution is filtrated to separate the precipitates. The precipitates then are dried at 100° C. under air flow to produce dried precipitates. The dried precipitates are calcined in air flowing at 100 mL/min flow while heating at 1.5° C./min to 450° C. The precipitates are maintained at 450° C. for 6 hours to produce La 0.1 Ce 0.9 O 2 adsorbent.
EXAMPLE 2
Manufacture of Y 0.1 Ce 0.9 O 2 Adsorbent
[0026] Urea in an amount of 35 g is placed in a glass beaker, and 800 ml deionized water is added to make 800 ml of 0.728 M aqueous urea solution.
[0027] 8.22 g of 99.99% pure ammonium cerium nitrate from Aldrich is dissolved in 100 ml deionized water to make 100 mL of 0.149 M ammonium cerium nitrate solution.
[0028] 0.5795 g of 99.9% pure yttrium nitrate hydrate from Aldrich is dissolved in 100 ml deionized water to make 100 mL of 0.013 M yttrium nitrate solution.
[0029] 100 mL of the yttrium nitrate hydrate solution is mixed with 100 mL of the ammonium cerium nitrate solution to form a first solution.
[0030] All of the first solution is mixed with 800 ml of the aqueous solution and vigorously mixed by magnetic stirrer to produce a mixed solution.
[0031] The mixed solution is heated at 2° C./min to 90° C., maintained at 90° C. for 8 hours to produce precipitates, and then cooled at 10° C./min to room temperature to produce a cooled slurry solution. The cooled slurry solution is filtrated to separate the precipitates.
[0032] The precipitates then are dried at 100° C. under air flow to produce dried precipitates. The dried precipitates are calcined in air flowing at 100 mL/min flow while heating at 1.5° C./min to 450° C. The precipitates are maintained at 450° C. for 6 hours to yield Y 0.1 Ce 0.9 O 2
EXAMPLE 2A
Manufacture of Sc 0.1 Ce 0.9 O 2 Adsorbent
[0033] Urea in an amount of 35 g is placed in a glass beaker, and 800 ml deionized water is added to make 800 ml of 0.728 M aqueous urea solution.
[0034] 8.22 g of 99.99% pure ammonium cerium nitrate from Aldrich is dissolved in 100 ml deionized water to make 100 mL of 0.149 M ammonium cerium nitrate solution.
[0035] 0.388 g of 99% pure scandium nitrate from Aldrich is dissolved in 100 ml deionized water to make 100 mL of 0.017 M scandium nitrate solution. 100 mL of the scandium nitrate solution is mixed with 100 mL of the ammonium cerium nitrate solution to form a first solution.
[0036] All of the first solution is mixed with 800 ml of the aqueous solution and vigorously mixed by magnetic stirrer to produce a mixed solution. The mixed solution is heated at 2° C./min to 90° C., maintained at 90° C. for 8 hours to produce precipitates, and then, cooled at 10° C./min to room temperature to produce a cooled slurry solution.
[0037] The cooled slurry solution is filtrated to separate the precipitates. The precipitates are dried at 100° C. under air flow. The dried precipitates are calcined in air flowing at 100 mL/min flow while heating at 1.5° C./min to 450° C. The precipitates are maintained at 450° C. for 6 hours to yield Sc 0.1 Ce 0.9 O 2 adsorbent.
EXAMPLE 3
Manufacture of Cu 0.1 Ce 0.9 O 2 Adsorbent
[0038] Urea in an amount of 35 g is placed in a glass beaker, and 800 ml deionized water is added to make 800 ml of 0.728 M aqueous urea solution.
[0039] 8.22 g of 99.99% pure ammonium cerium nitrate from Aldrich is dissolved in 100 ml deionized water to make 100 mL of 0.149 M ammonium cerium nitrate solution.
[0040] 0.4142 g of 98% pure copper nitrate hydrate from Aldrich is dissolved in 100 ml deionized water to make 100 mL of 0.016 M copper nitrate-solution.
[0041] 100 mL of the copper nitrate hydrate solution is mixed with 100 mL of the ammonium cerium nitrate solution to form a first solution.
[0042] All of the first solution is mixed with 800 ml of the aqueous solution and vigorously mixed by magnetic stirrer to produce a mixed solution. The mixed solution is heated at 2° C./min to 90° C., maintained at 90° C. for 8 hours to produce precipitates, and then, cooled at 10° C./min to room temperature to produce a cooled slurry solution.
[0043] The cooled slurry solution is filtrated to separate the precipitates. The precipitates are dried at 100° C. under air flow. The dried precipitates are calcined in air flowing at 100 mL/min flow while heating at 1.5° C./min to 450° C. The precipitates are maintained at 450° C. for 6 hours to yield Cu 0.1 Ce 0.9 O 2 adsorbent.
EXAMPLE 3A
Manufacture of Au 0.1 Ce 0.9 O 2 Adsorbent
[0044] Urea in an amount of 35 g is placed in a glass beaker, and 800 ml deionized water is added to make 800 ml of 0.728 M aqueous urea solution.
[0045] 8.22 g of 99.99% pure ammonium cerium nitrate from Aldrich is dissolved in 100 ml deionized water to make 100 mL of 0.149 M ammonium cerium nitrate solution.
[0046] 0.5663 g of 99.999% pure gold chloride hydrate from Aldrich is dissolved in 100 ml deionized water to make 100 mL of 0.015 M gold chloride solution.
[0047] 100 mL of the gold chloride solution is mixed with 100 mL of the ammonium cerium nitrate solution to form a first solution.
[0048] All of the first solution is mixed with 800 ml of the aqueous solution and vigorously mixed by magnetic stirrer to produce a mixed solution. The mixed solution is heated at 2° C./ min to 90° C., maintained at 90° C. for 8 hours to produce precipitates, and then, cooled at 10° C./min to room temperature to produce a cooled slurry solution.
[0049] The cooled slurry solution is filtrated to separate the precipitates. The precipitates then are dried at 100° C. under air flow. The dried precipitates are calcined in air flowing at 100 mL/min flow while heating at 1.5° C./min to 450° C. The precipitates are maintained at 450° C. for 6 hours to yield Au 0.1 Ce 0.9 O 2 adsorbent.
EXAMPLE 4
Manufacture of Ni 0.1 Ce 0.9 O 2 Adsorbent
[0050] Urea in an amount of 35 g is placed in a glass beaker, and 800 ml deionized water is added to make 800 ml of 0.728 M aqueous urea solution.
[0051] 8.22 g of 99.99% pure ammonium cerium nitrate from Aldrich is dissolved in 100 ml deionized water to make 100 mL of 0.149 M ammonium cerium nitrate solution. 0.3826 g of 99.999% pure nickel nitrate hydrate from Aldrich is dissolved in 100 ml deionized water to make 100 mL of 0.013 M nickel nitrate solution.
[0052] 100 mL of the nickel nitrate solution is mixed with 100 mL of the ammonium cerium nitrate solution to form a first solution.
[0053] All of the first solution is mixed with 800 ml of the aqueous solution and vigorously mixed by magnetic stirrer to produce a mixed solution. The mixed solution is heated at 2° C./min to 90° C., maintained at 90° C. for 8 hours to produce precipitates, and then, cooled at 10° C./min to room temperature to produce a cooled slurry solution.
[0054] The cooled slurry solution is filtrated to separate the precipitates. The precipitates then are dried at 100° C. under air flow. The dried precipitates are calcined in air flowing at 100 mL/min flow while heating at 1.5° C./min to 450° C. The precipitates are maintained at 450° C. for 6 hours to yield Ni 0.1 Ce 0.9 O 2 adsorbent.
EXAMPLE 4A
Manufacture of Pd 0.1 Ce 0.9 O 2 Adsorbent
[0055] Urea in an amount of 35 g is placed in a glass beaker, and 800 ml deionized water is added to make 800 ml of 0.728 M aqueous urea solution.
[0056] 8.22 g of 99.99% pure ammonium cerium nitrate from Aldrich is dissolved in 100 ml deionized water to make 100 mL of 0.149 M ammonium cerium nitrate solution.
[0057] 0.2956 g of 99% pure palladium chloride from Aldrich is dissolved in 100 ml deionized to make 100 mL of 0.015 M palladium chloride solution.
[0058] 100 mL of the palladium chloride solution is mixed with 100 mL of the ammonium cerium nitrate solution to form a first solution.
[0059] All of the first solution is mixed with 800 ml of the aqueous solution and vigorously mixed by magnetic stirrer to produce a mixed solution. The mixed solution is heated at 2° C./min to 90° C., maintained at 90° C. for 8 hours to produce precipitates, and then cooled at 10° C./min to room temperature to produce a cooled slurry solution. The cooled slurry solution is filtrated to separate the precipitates. The precipitates are dried at 100° C. under air flow. The dried precipitates are calcined in air flowing at 100 mL/min flow while heating at 1.5° C./min to 450° C. The precipitates are maintained at 450° C. for 6 hours to yield Pd 0.1 Ce 0.9 O 2 adsorbent.
EXAMPLE 4B
Manufacture of Pt 0.1 Ce 0.9 O 2
[0060] Urea in an amount of 35 g is placed in a glass beaker, and 800 ml deionized water is added to make 800 ml of 0.728 M aqueous urea solution.
[0061] 8.22 g of 99.99% pure ammonium cerium nitrate from Aldrich is dissolved in 100 ml deionized water to make 100 mL of 0.149 M ammonium cerium nitrate solution.
[0062] 0.5614 g of 99% pure platinum chloride from Aldrich is dissolved in 100 ml deionized water to make 100 mL of 0.015 M platinum chloride solution.
[0063] 100 mL of the platinum chloride solution is mixed with 100 mL of the ammonium cerium nitrate solution to form a first solution.
[0064] All of the first solution is mixed with 800 ml of the aqueous solution and vigorously mixed by magnetic stirrer to produce a mixed solution. The mixed solution is heated at 2° C./min to 90° C., maintained at 90° C. for 8 hours to produce precipitates, and then, cooled at 10° C./min to room temperature to produce a cooled slurry solution.
[0065] The cooled slurry solution is filtrated to separate the precipitates. The precipitates are dried at 100° C. under air flow. The dried precipitates are calcined in air flowing at 100 mL/min flow while heating at 1.5° C./min to 450° C. The precipitates are maintained at 450° C. for 6 hours to yield Pt 0.1 Ce 0.9 O 2 adsorbent.
EXAMPLE 5
Manufacture of Ca 0.1 Ce 0.9 O 2 Adsorbent
[0066] Urea in an amount of 35 g is placed in a glass beaker, and 800 ml deionized water is added to make 800 ml of 0.728 M aqueous urea solution. 8.22 g of 99.99% pure ammonium cerium nitrate from Aldrich is dissolved in 100 ml deionized water to make 100 mL of 0.149 M ammonium cerium nitrate solution.
[0067] 0.2612 g of 99% pure calcium nitrate from Aldrich is dissolved in 100 ml deionized water to make 100 mL of 0.014 M calcium nitrate solution.
[0068] 100 mL of the calcium nitrate solution is mixed with 100 mL of the ammonium cerium nitrate solution to form a first solution.
[0069] All of the first solution is mixed with 800 ml of the aqueous solution and vigorously mixed by magnetic stirrer to produce a mixed solution. The mixed solution is heated at 2° C./min to 90° C., maintained at 90° C. for 8 hours to produce precipitates, and then, cooled at 10° C./min to room temperature to produce a cooled slurry solution.
[0070] The cooled slurry solution is filtrated to separate the precipitates. The precipitates are dried at 100° C. under air flow. The dried precipitates are calcined in air flowing at 100 mL/min flow while heating at 1.5° C./min to 450° C. The precipitates are maintained at 450° C. for 6 hours to yield Ca 0.1 Ce 0.9 O 2 adsorbent.
EXAMPLE 5A
Manufacture of Be 0.1 Ce 0.9 O 2 Adsorbent
[0071] Urea in an amount of 35 g is placed in a glass beaker, and 800 ml deionized water is added to make 800 ml of 0.728 M aqueous urea solution.
[0072] 8.22 g of 99.99% pure ammonium cerium nitrate from Aldrich is dissolved in 100 ml deionized water to make 100 mL of 0.149 M ammonium cerium nitrate solution.
[0073] 0.2993 g of 99% pure beryllium nitrate solution from Aldrich is dissolved in 100 ml deionized water to make 100 mL of 0.020 M beryllium nitrate solution.
[0074] 100 mL of the beryllium nitrate solution is mixed with 100 mL of the ammonium cerium nitrate solution to form a first solution.
[0075] All of the first solution is mixed with 800 ml of the aqueous solution and vigorously mixed by magnetic stirrer to produce a mixed solution. The mixed solution is heated at 2° C./min to 90° C., maintained at 90° C. for 8 hours to produce precipitates, and then, cooled at 10° C./min to room temperature to produce a cooled slurry solution.
[0076] The cooled slurry solution is filtrated to separate the precipitates. The precipitates are dried at 100° C. under air flow. The dried precipitates are calcined in air flowing at 100 mL/min flow while heating at 1.5° C./min to 450° C. The precipitates are maintained at 450° C. for 6 hours to yield Be 0.1 Ce 0.9 O 2 adsorbent.
EXAMPLE 5B
Manufacture of Mg 0.1 Ce 0.9 O 2 Adsorbent
[0077] Urea in an amount of 35 g is placed in a glass beaker, and 800 ml deionized water is added to make 800 ml of 0.728 M aqueous urea solution.
[0078] 8.22 g of 99.99% pure ammonium cerium nitrate from Aldrich is dissolved in 100 ml deionized water to make 100 mL of 0.149 M ammonium cerium nitrate solution.
[0079] 0.4274 g of 99% pure magnesium nitrate hexahydrate from Aldrich is dissolved in 100 ml deionized water to make 100 mL of 0.015 M magnesium nitrate solution.
[0080] 100 mL of the magnesium nitrate solution is mixed with 100 mL of the ammonium cerium nitrate solution to form a first solution.
[0081] All of the first solution is mixed with 800 ml of the aqueous solution and vigorously mixed by magnetic stirrer to produce a mixed solution. The mixed solution is heated at 2° C./min to 90° C., maintained at 90° C. for 8 hours to produce precipitates, and then, cooled at 10° C./min to room temperature to produce a cooled slurry solution.
[0082] The cooled slurry solution is filtrated to separate the precipitates. The precipitates are dried at 100° C. under air flow. The dried precipitates are calcined in air flowing at 100 mL/min flow while heating at 1.5° C./min to 450° C. The precipitates are maintained at 450° C. for 6 hours to yield Mg 0.1 Ce 0.9 O 2 adsorbent.
EXAMPLE 5C
Manufacture of Ba 0.1 Ce 0.9 O 2 Adsorbent
[0083] Urea in an amount of 35 g is placed in a glass beaker, and 800 ml deionized water is added to make 800 ml of 0.728 M aqueous urea solution.
[0084] 8.22 g of 99.99% pure ammonium cerium nitrate from Aldrich is dissolved in 100 ml deionized water to make 100 mL of 0.149 M ammonium cerium nitrate solution.
[0085] 0.4356 g of 90% pure barium nitrate hydrate from Aldrich is dissolved in 100 ml deionized water to make 100 mL of 0.015 M barium nitrate solution.
[0086] 100 mL of the barium nitrate solution is mixed with 100 mL of the ammonium cerium nitrate solution to form a first solution.
[0087] All of the first solution is mixed with 800 ml of the aqueous solution and vigorously mixed by magnetic stirrer to produce a mixed solution. The mixed solution is heated at 2° C./min to 90° C., maintained at 90° C. for 8 hours to produce precipitates, and then, cooled at 10° C./min to room temperature to produce a cooled slurry solution.
[0088] The cooled slurry solution is filtrated to separate the precipitates. The precipitates are dried at 100° C. under air flow. The dried precipitates are calcined in air flowing at 100 mL/min flow while heating at 1.5° C./min to 450° C. The precipitates are maintained at 450° C. for 6 hours to yield Ba 0.1 Ce 0.9 O 2 Adsorbent.
EXAMPLE 6
Manufacture of Ag 0.1 Ce 0.9 O 2 Adsorbent
[0089] Urea in an amount of 35 g is placed in a glass beaker, and 800 ml deionized water is added to make 800 ml of 0.728 M aqueous urea solution.
[0090] 8.22 g of 99.99% pure ammonium cerium nitrate from Aldrich is dissolved in 100 ml deionized water to make 100 mL of 0.149 M ammonium cerium nitrate solution.
[0091] 0.7031 g of 99% pure silver nitrate from Aldrich is dissolved in 100 ml deionized water to make 100 mL of 0.037 M silver nitrate solution.
[0092] 100 mL of the silver nitrate solution is mixed with 100 mL of the ammonium cerium nitrate solution to form a first solution.
[0093] All of the first solution is mixed with 800 ml of the aqueous solution and vigorously mixed by magnetic stirrer to produce a mixed solution. The mixed solution is heated at 2° C./min to 90° C., maintained at 90° C. for 8 hours to produce precipitates, and then, cooled at 10° C./min to room temperature to produce a cooled slurry solution.
[0094] The cooled slurry solution is filtrated to separate the precipitates. The precipitates then are dried at 100° C. under air flow. The dried precipitates are calcined in air flowing at 100 mL/min flow while heating at 1.5° C./min to 450° C. The precipitates are maintained at 450° C. for 6 hours to yield Ag 0.1 Ce 0.9 O 2 adsorbent.
EXAMPLE 7
Manufacture of Sr 0.1 Ce 0.9 O 2 Adsorbent
[0095] Urea in an amount of 35 g is placed in a glass beaker, and 800 ml deionized water is added to make 800 ml of 0.728 M aqueous urea solution.
[0096] 8.22 g of 99.99% pure ammonium cerium nitrate from Aldrich is dissolved in 100 ml deionized water to make 100 mL of 0.149 M ammonium cerium nitrate solution.
[0097] 0.5711 g of 99% pure strontium nitrate from Aldrich is dissolved in 100 ml deionized water to make 100 mL of 0.024 M strontium nitrate solution.
[0098] 100 mL of the strontium nitrate solution is mixed with 100 mL of the ammonium cerium nitrate solution to form a first solution.
[0099] All of the first solution is mixed with 800 ml of the aqueous solution and vigorously mixed by magnetic stirrer to produce a mixed solution. The mixed solution is heated at 2° C./min to 90° C., maintained at 90° C. for 8 hours to produce precipitates, and then, cooled at 10° C./min to room temperature to produce a cooled slurry solution.
[0100] The cooled slurry solution is filtrated to separate the precipitates. The precipitates then are dried at 100° C. under air flow. The dried precipitates are calcined in air flowing at 100 mL/min flow while heating at 1.5° C./min to 450° C. The precipitates are maintained at 450° C. for 6 hours to yield Sr 0.1 Ce 0.9 O 2 adsorbent.
EXAMPLE 8
Manufacture of Pb 0.1 Ce 0.9 O 2 Adsorbent
[0101] Urea in an amount of 35 g is placed in a glass beaker, and 800 ml deionized water is added to make 800 ml of 0.728 M aqueous urea solution.
[0102] 8.22 g of 99.99% pure ammonium cerium nitrate from Aldrich is dissolved in 100 ml deionized water to make 100 mL of 0.149 M ammonium cerium nitrate solution.
[0103] 1.3506 g of 99% pure lead nitrate from Aldrich is dissolved in 100 ml deionized water to make 100 mL of 0.036 M lead nitrate solution.
[0104] 100 mL of the lead nitrate solution is mixed with 100 mL of the ammonium cerium nitrate solution to form a first solution.
[0105] All of the first solution is mixed with 800 ml of the aqueous solution and vigorously mixed by magnetic stirrer to produce a mixed solution. The mixed solution is heated at 2° C./min to 90° C., maintained at 90° C. for 8 hours to produce precipitates, and then, cooled at 10° C./min to room temperature to produce a cooled slurry solution.
[0106] The cooled slurry solution is filtrated to separate the precipitates. The precipitates then are dried at 100° C. under air flow. The dried precipitates are calcined in air flowing at 100 mL/min flow while heating at 1.5° C./min to 450° C. The precipitates are maintained at 450° C. for 6 hours to yield Pb 0.1 Ce 0.9 O 2 adsorbent.
EXAMPLE 8A
Manufacture of Ge 0.1 Ce 0.9 O 2 Adsorbent
[0107] Urea in an amount of 35 g is placed in a glass beaker, and 800 ml deionized water is added to make 800 ml of 0.728 M aqueous urea solution.
[0108] 8.22 g of 99.99% pure ammonium cerium nitrate from Aldrich is dissolved in 100 ml deionized water to make 100 mL of 0.149 M ammonium cerium nitrate solution.
[0109] 0.3574 g of germanium chloride from Aldrich is dissolved in 100 ml deionized water to make 100 mL of 0.015 M germanium chloride solution.
[0110] 100 mL of the germanium chloride solution is mixed with 100 mL of the ammonium cerium nitrate solution to form a first solution.
[0111] All of the first solution is mixed with 800 ml of the aqueous solution and vigorously mixed by magnetic stirrer to produce a mixed solution. The mixed solution is heated at 2° C./min to 90° C., maintained at 90° C. for 8 hours to produce precipitates, and then, cooled at 10° C./min to room temperature to produce a cooled slurry solution.
[0112] The cooled slurry solution is filtrated to separate the precipitates. The precipitates are dried at 100° C. under air flow. The dried precipitates are calcined in air flowing at 100 mL/min flow while heating at 1.5° C./min to 450° C. The precipitates are maintained at 450° C. for 6 hours to yield Pd 0.1 Ce 0.9 O 2 adsorbent.
EXAMPLE 8B
Manufacture of Sn 0.1 Ce 0.9 O 2 Adsorbent
[0113] Urea in an amount of 35 g is placed in a glass beaker, and 800 ml deionized water is added to make 800 ml of 0.728 M aqueous urea solution.
[0114] 8.22 g of 99.99% pure ammonium cerium nitrate from Aldrich is dissolved in 100 ml deionized water to make 100 mL of 0.149 M ammonium cerium nitrate solution.
[0115] 0.4342 g of 98% pure tin chloride from Aldrich is dissolved in 100 ml deionized water to make 100 mL of 0.015 M tin chloride solution.
[0116] 100 mL of the tin chloride solution is mixed with 100 mL of the ammonium cerium nitrate solution to form a first solution.
[0117] All of the first solution is mixed with 800 ml of the aqueous solution and vigorously mixed by magnetic stirrer to produce a mixed solution. The mixed solution is heated at 2° C./min to 90° C., maintained at 90° C. for 8 hours to produce precipitates, and then, cooled at 10° C./min to room temperature to produce a cooled slurry solution. The cooled slurry solution is filtrated to separate the precipitates. The precipitates are dried at 100° C. under air flow. The dried precipitates are calcined in air flowing at 100 mL/min flow while heating at 1.5° C./min to 450° C. The precipitates are maintained at 450° C. for 6 hours to yield Sn 0.1 Ce 0.9 O 2 adsorbent.
[0118] Particularly preferred adsorbents are TiO 2 —CeO 2 based adsorbents of the formula Ti x Ce y O 2 , where 0<x/y≦1 and where 0<x<1 and 0<y<1.
EXAMPLE 9
Manufacture of Ti 0.1 Ce 0.9 O 2 Adsorbent
[0119] Urea in an amount of 35 g is placed in a glass beaker, and 800 ml deionized water is added to make 800 ml of 0.728 M aqueous urea solution. 8.22 g of 99.99% pure ammonium cerium nitrate from Aldrich is dissolved in 100 ml deionized water to make 100 mL of 0.149 M ammonium cerium nitrate solution.
[0120] 0.3120 g of synthesis grade titanium oxysulfate-sulfuric acid complex hydrate from Aldrich is dissolved in 100 ml deionized water over a period of 1.5 hours to make 100 mL of titanium oxysulfate-sulfuric acid solution.
[0121] 100 mL of the titanium oxysulfate-sulfuric acid complex hydrate solution is mixed with 100 mL of the ammonium cerium nitrate solution to form a first solution.
[0122] All of the first solution is mixed with 800 ml of the aqueous solution and vigorously mixed by magnetic stirrer to produce a mixed solution. The mixed solution is heated at 2° C./min to 90° C., maintained at 90° C. for 8 hours to produce precipitates, and then, cooled at 10° C./min to room temperature to produce a cooled slurry solution.
[0123] The cooled slurry solution is filtrated to separate the precipitates. The precipitates then are dried at 100° C. under air flow to produce dried precipitates. The dried precipitates are calcined in air flowing at 100 mL/min flow while heating at 1.5° C./min to 450° C. The precipitates are maintained at 450° C. for 6 hours to yield Ti 0.1 Ce 0.9 O 2 adsorbent.
EXAMPLE 9A
Manufacture of Zr 0.1 Ce 0.9 O 2 Adsorbent
[0124] Urea in an amount of 35 g is placed in a glass beaker, and 800 ml deionized water is added to make 800 ml of 0.728 M aqueous urea solution.
[0125] 8.22 g of 99.99% pure ammonium cerium nitrate from Aldrich is dissolve in 100 ml deionized water to make 100 mL of 0.149 M ammonium cerium nitrate solution.
[0126] 0.3854 g of 99% pure zirconyl nitrate from Aldrich is dissolved in 100 ml deionized water to make 100 mL of 0.015 M zirconyl nitrate solution.
[0127] 100 mL of the zirconyl nitrate solution is mixed with 100 mL of the ammonium cerium nitrate solution to form a first solution.
[0128] All of the first solution is mixed with 800 ml of the aqueous solution and vigorously mixed by magnetic stirrer to produce a mixed solution. The mixed solution is heated at 2° C./min to 90° C., maintained at 90° C. for 8 hours to produce precipitates, and then, cooled at 10° C./min to room temperature to produce a cooled slurry solution.
[0129] The cooled slurry solution is filtrated to separate the precipitates. The precipitates are dried at 100° C. under air flow. The dried precipitates are calcined in air flowing at 100 mL/min flow while heating at 1.5° C./min to 450° C. The precipitates are maintained at 450° C. for 6 hours to yield Zr 0.1 Ce 0.9 O 2 adsorbent.
EXAMPLE 9B
Manufacture of Hf 0.1 Ce 0.9 O 2 Adsorbent
[0130] Urea in an amount of 35 g is placed in a glass beaker, and 800 ml deionized water is added to make 800 ml of 0.728 M aqueous urea solution.
[0131] 8.22 g of 99.99% pure ammonium cerium nitrate from Aldrich is dissolved in 100 ml deionized water to make 100 mL of 0.149 M ammonium cerium nitrate solution.
[0132] 0.5338 g of 98% pure hafnium chloride from Aldrich is dissolved in 100 ml deionized water to make 100 mL of 0.015 M hafnium chloride solution.
[0133] 100 mL of the hafnium chloride solution is mixed with 100 mL of the ammonium cerium nitrate solution to form a first solution.
[0134] All of the first solution is mixed with 800 ml of the aqueous solution and vigorously mixed by magnetic stirrer to produce a mixed solution. The mixed solution is heated at 2° C./min to 90° C., maintained at 90° C. for 8 hours to produce precipitates, and then, cooled at 10° C./min to room temperature to produce a cooled slurry solution.
[0135] The cooled slurry solution is filtrated to separate the precipitates. The precipitates are dried at 100° C. under air flow. The dried precipitates are calcined in air flowing at 100 mL/min flow while heating at 1.5° C./min to 450° C. The precipitates are maintained at 450° C. for 6 hours to yield Hf 0.1 Ce 0.9 O 2 adsorbent.
EXAMPLE 10
Manufacture of Co 0.1 Ce 0.9 O 2 Adsorbent
[0136] Urea in an amount of 35 g is placed in a glass beaker, and 800 ml deionized water is added to make 800 ml of 0.728 M aqueous urea solution.
[0137] 8.22 g of 99.99% pure ammonium cerium nitrate from Aldrich is dissolved in 100 ml deionized water to make 100 mL of 0.149 M ammonium cerium nitrate solution.
[0138] 0.3842 g of 99% pure cobalt nitrate hydrate from Aldrich is dissolved in 100 ml deionized water to make 100 mL of 0.013 M cobalt nitrate solution.
[0139] 100 mL of the cobalt nitrate solution is mixed with 100 mL of the ammonium cerium nitrate solution to form a first solution.
[0140] All of the first solution is mixed with 800 ml of the aqueous solution and vigorously mixed by magnetic stirrer to produce a mixed solution. The mixed solution is heated at 2° C./min to 90° C., maintained at 90° C. for 8 hours to produce precipitates, and then, cooled at 10° C./min to room temperature to produce a cooled slurry solution.
[0141] The cooled slurry solution is filtrated to separate the precipitates. The precipitates then are dried at 100° C. under air flow to produce dried precipitates. The dried precipitates are calcined in air flowing at 100 mL/min flow while heating at 1.5° C./min to 450° C. The precipitates are maintained at 450° C. for 6 hours to yield Co 0.1 Ce 0.9 O 2 adsorbent.
EXAMPLE 10A
Manufacture of Rh 0.1 Ce 0.9 O 2 Adsorbent
[0142] Urea in an amount of 35 g is placed in a glass beaker, and 800 ml deionized water is added to make 800 ml of 0.728 M aqueous urea solution.
[0143] 8.22 g of 99.99% pure ammonium cerium nitrate from Aldrich is dissolved in 100 ml deionized water to make 100 mL of 0.149 M ammonium cerium nitrate solution. 0.3488 g of 98% pure rhodium chloride from Aldrich is dissolved in 100 ml deionized to make 100 mL of 0.015 M rhodium chloride solution.
[0144] 100 mL of the rhodium chloride solution is mixed with 100 mL of the ammonium cerium nitrate solution to form a first solution.
[0145] All of the first solution is mixed with 800 ml of the aqueous solution and vigorously mixed by magnetic stirrer to produce a mixed solution. The mixed solution is heated at 2° C./min to 90° C., maintained at 90° C. for 8 hours to produce precipitates, and then, cooled at 10° C./min to room temperature to produce a cooled slurry solution.
[0146] The cooled slurry solution is filtrated to separate the precipitates. The precipitates are dried at 100° C. under air flow. The dried precipitates are calcined in air flowing at 100 mL/min flow while heating at 1.5° C./min to 450° C. The precipitates are maintained at 450° C. for 6 hours to yield Rh 0.1 Ce 0.9 O 2 adsorbent.
EXAMPLE 10B
Manufacture of Ir 0.1 Ce 0.9 O 2 Adsorbent
[0147] Urea in an amount of 35 g is placed in a glass beaker, and 800 ml deionized water is added to make 800 ml of 0.728 M aqueous urea solution.
[0148] 8.22 g of 99.99% pure ammonium cerium nitrate from Aldrich is dissolved in 100 ml deionized water to make 100 mL of 0.149 M ammonium cerium nitrate solution.
[0149] 0.4976 g of 99.9% pure iridium chloride from Aldrich is dissolved in 100 ml deionized water to make 100 mL of 0.015 M iridium chloride solution.
[0150] 100 mL of the iridium chloride solution is mixed with 100 mL of the ammonium cerium nitrate solution to form a first solution.
[0151] All of the first solution is mixed with 800 ml of the aqueous solution and vigorously mixed by magnetic stirrer to produce a mixed solution. The mixed solution is heated at 2° C./min to 90° C., maintained at 90° C. for 8 hours to produce precipitates, and then, cooled at 10° C./min to room temperature to produce a cooled slurry solution.
[0152] The cooled slurry solution is filtrated to separate the precipitates. The precipitates are dried at 100° C. under air flow. The dried precipitates are calcined in air flowing at 100 mL/min flow while heating at 1.5° C./min to 450° C. The precipitates are maintained at 450° C. for 6 hours to yield Ir 0.1 Ce 0.9 O 2 adsorbent.
EXAMPLE 11
Manufacture of Fe 0.1 Ce 0.9 O 2 Adsorbent
[0153] Urea in an amount of 35 g is placed in a glass beaker, and 800 ml deionized water is added to make 800 ml of 0.728 M aqueous urea solution.
[0154] 8.22 g of 99.99% pure ammonium cerium nitrate from Aldrich is dissolved in 100 ml deionized water to make 100 mL of 0.149 M ammonium cerium nitrate solution.
[0155] 0.3640 g of 99% pure iron nitrate hydrate from Aldrich is dissolved in 100 ml deionized water to make 100 mL of 0.015M ferrous nitrate solution.
[0156] 100 mL of the iron nitrate solution is mixed with 100 mL of the ammonium cerium nitrate solution to form a first solution.
[0157] All of the first solution is mixed with 800 ml of the aqueous solution and vigorously mixed by magnetic stirrer to produce a mixed solution. The mixed solution is heated at 2° C./min to 90° C., maintained at 90° C. for 8 hours to produce precipitates, and then, cooled at 10° C./min to room temperature to produce a cooled slurry solution.
[0158] The cooled slurry solution is filtrated to separate the precipitates. The precipitates then are dried at 100° C. under air flow to produce dried precipitates. The dried precipitates are calcined in air flowing at 100 mL/min flow while heating at 1.5° C./min to 450° C. The precipitates are maintained at 450° C. for 6 hours to yield Fe 0.1 Ce 0.9 O 2 adsorbent.
EXAMPLE 11A
Manufacture of Ru 0.1 Ce 0.9 O 2 Adsorbent
[0159] Urea in an amount of 35 g is placed in a glass beaker, and 800 ml deionized water is added to make 800 ml of 0.728 M aqueous urea solution.
[0160] 8.22 g of 99.99% pure ammonium cerium nitrate from Aldrich is dissolved in 100 ml deionized water to make 100 mL of 0.149 M ammonium cerium nitrate solution.
[0161] 0.3457 g of 99.98% pure ruthenium chloride from Aldrich is dissolved in 100 ml deionized water to make 100 mL of 0.015 M ruthenium chloride solution.
[0162] 100 mL of the ruthenium chloride solution is mixed with 100 mL of the ammonium cerium nitrate solution to form a first solution.
[0163] All of the first solution is mixed with 800 ml of the aqueous solution and vigorously mixed by magnetic stirrer to produce a mixed solution. The mixed solution is heated at 2° C./min to 90° C., maintained at 90° C. for 8 hours to produce precipitates, and then, cooled at 10° C./min to room temperature to produce a cooled slurry solution.
[0164] The cooled slurry solution is filtrated to separate the precipitates. The precipitates are dried at 100° C. under air flow. The dried precipitates are calcined in air flowing at 100 mL/min flow while heating at 1.5° C./min to 450° C. The precipitates are maintained at 450° C. for 6 hours to yield R4 0.1 Ce 0.9 O 2 adsorbent.
EXAMPLE 11B
Manufacture of Os 0.1 Ce 0.9 O 2 Adsorbent
[0165] Urea in an amount of 35 g is placed in a glass beaker, and 800 ml deionized water is added to make 800 ml of 0.728 M aqueous urea solution.
[0166] 8.22 g of 99.99% pure ammonium cerium nitrate from Aldrich is dissolved in 100 ml deionized water to make 100 mL of 0.149 M ammonium cerium nitrate solution.
[0167] 0.4493 g of 95% osmium chloride hydrate from Aldrich is dissolved in 100 ml deionized water to make 100 mL of 0.015 M osmium chloride solution.
[0168] 100 mL of the osmium chlorite hydrate solution is mixed with 100 mL of the ammonium cerium nitrate solution to form a first solution.
[0169] All of the first solution is mixed with 800 ml of the aqueous solution and vigorously mixed by magnetic stirrer to produce a mixed solution. The mixed solution is heated at 2° C./min to 90° C., maintained at 90° C. for 8 hours to produce precipitates, and then, cooled at 10° C./min to room temperature to produce a cooled slurry solution.
[0170] The cooled slurry solution is filtrated to separate the precipitates. The precipitates are dried at 100° C. under air flow. The dried precipitates are calcined in air flowing at 100 mL/min flow while heating at 1.5° C./min to 450° C. The precipitates are maintained at 450° C. for 6 hours to yield Os 0.1 Ce 0.9 O 2 adsorbent.
EXAMPLE 12
Manufacture of W 0.1 Ce 0.9 O 2 Adsorbent
[0171] Urea in an amount of 35 g is placed in a glass beaker, and 800 ml deionized water is added to make 800 ml of 0.728 M aqueous urea solution.
[0172] 8.22 g of 99.99% pure ammonium cerium nitrate from Aldrich is dissolved in 100 ml deionized water to make 100 mL of 0.149 M ammonium cerium nitrate solution.
[0173] 0.1406 g of 99.99% pure ammonium metatungstate hydrate from Aldrich is dissolved in 100 ml deionized water to make 100 mL of 0.015 M W-containing solution.
[0174] 100 mL of the W-containing solution is mixed with 100 mL of the ammonium cerium nitrate solution to form a first solution.
[0175] All of the first solution is mixed with 800 ml of the aqueous solution and vigorously mixed by magnetic stirrer to produce a mixed solution. The mixed solution is heated at 2° C./min to 90° C., maintained at 90° C. for 8 hours to produce precipitates, and then, cooled at 10° C./min to room temperature to produce a cooled slurry solution.
[0176] The cooled slurry solution is filtrated to separate the precipitates. The precipitates then are dried at 100° C. under air flow to produce dried precipitates. The dried precipitates are calcined in air flowing at 100 mL/min flow while heating at 1.5° C./min to 450° C. The precipitates are maintained at 450° C. for 6 hours to yield W 0.1 Ce 0.9 O 2 adsorbent.
EXAMPLE 12A
Manufacture of Mo 0.1 Ce 0.9 O 2 Adsorbent
[0177] Urea in an amount of 35 g is placed in a glass beaker, and 800 ml deionized water is added to make 800 ml of 0.728 M aqueous urea solution.
[0178] 8.22 g of 99.99% pure ammonium cerium nitrate from Aldrich is dissolved in 100 ml deionized water to make 100 mL of 0.149 M ammonium cerium nitrate solution.
[0179] 0.2943 g of 99.98% pure ammonium molybdate tetrahydrate from Aldrich is dissolved in 100 ml deionized water to make 100 mL of 0.015 M ammonium molybdate tetrahydrate solution. 100 mL of the ammonium molybdate tetrahydrate solution is mixed with 100 mL of the ammonium cerium nitrate solution to form a first solution.
[0180] All of the first solution is mixed with 800 ml of the aqueous solution and vigorously mixed by magnetic stirrer to produce a mixed solution. The mixed solution is heated at 2° C./min to 90° C., maintained at 90° C. for 8 hours to produce precipitates, and then, cooled at 10° C./min to room temperature to produce a cooled slurry solution.
[0181] The cooled slurry solution is filtrated to separate the precipitates. The precipitates are dried at 100° C. under air flow. The dried precipitates are calcined in air flowing at 100 mL/min flow while heating at 1.5° C./min to 450° C. The precipitates are maintained at 450° C. for 6 hours to yield Mo 0.1 Ce 0.9 O 2 adsorbent.
EXAMPLE 12B
Manufacture of Cr 0.1 Ce 0.9 O 2 Adsorbent
[0182] Urea in an amount of 35 g is placed in a glass beaker, and 800 ml deionized water is added to make 800 ml of 0.728 M aqueous urea solution.
[0183] 8.22 g of 99.99% pure ammonium cerium nitrate from Aldrich is dissolved in 100 ml deionized water to make 100 mL of 0.149 M ammonium cerium nitrate.
[0184] 0.670 g of 99% pure chromium nitrate nonahydrate from Aldrich is dissolved in 100 ml deionized to make 100 mL of 0.015M chromium nitrate solution.
[0185] 100 mL of the nitrate nonahydrate solution is mixed with 100 mL of the ammonium cerium nitrate solution to form a first solution.
[0186] All of the first solution is mixed with 800 ml of the aqueous solution and vigorously mixed by magnetic stirrer to produce a mixed solution. The mixed solution is heated at 2° C./min to 90° C., maintained at 90° C. for 8 hours to produce precipitates, and then, cooled at 10° C./min to room temperature to produce a cooled slurry solution.
[0187] The cooled slurry solution is filtrated to separate the precipitates. The precipitates are dried at 100° C. under air flow. The dried precipitates are calcined in air flowing at 100 mL/min flow while heating at 1.5° C./min to 450° C. The precipitates are maintained at 450° C. for 6 hours to yield Cr 0.1 Ce 0.9 O 2 adsorbent
Adsorption Performance
[0188] During adsorption tests of the adsorbents of Examples 1-12, model fuel (I) having the composition shown in Table A is passed at a flow rate of 0.05 mL/min over 1 g of adsorbent in a bed having the dimensions of 4.6 mm (ID)×37.5 mm (length) at room temperature (25° C.) and 4.8 −1 LHSV (liquid hour space velocity).
[0189] The sulfur breakthrough capacity (mg-S/Ads-g) at sulfur levels of 1 ppmw and 30 ppmw, respectively, are measured by analyzing sulfur concentration at the outlet of the bed using gas chromatography—with a flame ionization detector (“GC-FID”).
[0190] The adsorptive breakthrough capacities of the adsorbents at sulfur levels of 1 ppmw and 30 ppmw, respectively, are shown in Table 1.
[0000]
TABLE A
Model fuel (I) composition
S conc.
Mol conc.
Compound
(ppmw)
(%)
Sulfur
Thiophene (T)
110
0.034
Tetrahydrothiophene (THT)
95
0.030
2-methyl benzothiophene (2MBT)
115
0.036
Benzothiophene (BT)
100
0.031
Aromatics
Toluene
0.033
Olefin
1-C 8
0.033
Internal standard (IS)
n-C 9
0.033
Solvent
n-C 7
99.770
[0000] TABLE 1 Capacity: mg-S/Ads.-g Capacity: mg-S/Ads.-g Example Adsorbent (<1 ppmw) (<30 ppmw) 1 La 0.1 Ce 0.9 O 2 0.00 0.00 2 Y 0.1 Ce 0.9 O 2 0.00 0.00 3 Cu 0.1 Ce 0.9 O 2 0.19 0.33 4 Ni 0.1 Ce 0.9 O 2 0.00 0.38 5 Ca 0.1 Ce 0.9 O 2 0.00 0.07 6 Ag 0.1 Ce 0.9 O 2 0.20 0.36 7 Sr 0.1 Ce 0.9 O 2 0.00 0.07 8 Pb 0.1 Ce 0.9 O 2 0.00 0.00 9 Ti 0.1 Ce 0.9 O 2 0.55 0.86 10 Co 0.1 Ce 0.9 O 2 0.22 0.48 11 Fe 0.1 Ce 0.9 O 2 0.00 0.28 12 W 0.1 Ce 0.9 O 2 0.98 0.98
The adsorption capacities of the fresh and regenerated Ti 0.1 Ce 0.9 O 2 adsorbents of Example 9 also are measured in a fixed-bed flow system. Adsorption by the fixed-bed flow system entails first pretreating a fixed bed of the adsorbent by passing air/O 2 which contains oxygen in an amount of 21 vol. % at a flow rate of 100 ml/min through the adsorbent while increasing the temperature of the adsorbent to 350° C. for 2 hours to activate the adsorbent. The adsorbent then is cooled to room temperature under air/O 2 flow at 100 ml/min with heat turned off.
[0191] The adsorption is conducted at LHSV: 4.8 h −1 and room temperature using model fuel (I) feedstock. The spent adsorbents are regenerated by the procedure: 1) passing air at a flow rate of 100 ml/min through the adsorbent bed for 10 min; 2) increasing the temperature of the adsorbent bed to 375° C. at a rate of 15° C./min under 100 ml/min air flow; 3) holding at 375° C. for 120 min, and 4) cooling the temperature to room temperature under the air flow. Adsorption then again is conducted at LHSV: 4.8 h −1 and room temperature using model fuel (I). The adsorption capacity results for the fresh and regenerated adsorbents at sulfur levels of 1 ppmw and 30 ppmw, respectively, are shown in Table 2.
[0000]
TABLE 2
Capacity: mg-S/
Capacity: mg-S/
Ads.-g
Ads-g
Cycles
Sample
(<1 ppmw)
(<30 ppmw)
1
Fresh
2.3
3.3
Adsorbent
2
Regenerated
2.5
2.9
Adsorbent
EXAMPLE 13
Ti 0.1 Ce 0.9 O 2 Adsorbent Doped with 1 wt % of Pd Oxidation Catalyst
[0192] 1 wt. % Pd doped Ti 0.1 Ce 0.9 O 2 adsorbent is prepared by loading Pd onto the Ti 0.1 Ce 0.9 O 2 of example 9 by using the incipient wetness impregnation method. In this method, a Pd doping solution is prepared by dissolving 0.213 g of >99% pure tetrammine palladium (II) nitrate from Aldrich in 12.34 mL of deionized water. All of this solution is mixed with 11.5 gm of the precipitates dried at 450 C for 6 hours as in Example 9 to form Pd impregnated samples. The Pd impregnated samples are dried at 100° C. overnight to yield Ti 0.1 Ce 0.9 O 2 adsorbent doped with 1 wt % of Pd.
[0193] The adsorption capacities of fresh and regenerated 1 wt. % Pd doped Ti 0.1 Ce 0.9 O 2 adsorbent are evaluated in the fixed-bed flow system. Adsorption is conducted at room temperature and 1.2 h −1 of LHSV. Model fuel (II) having the composition shown in Table B is used for these tests. Regeneration is conducted at 375° C. under an air flow of 100 mL/min for 2 hrs at sulfur levels of 1 ppmw and 30 ppmw, respectively. The results are shown in Table 3.
[0000]
TABLE B
Model fuel (II) composition
S conc.
Mol conc.
Compound
(ppmw)
(%)
Sulfur
Thiophene (T)
50
0.021
2-methylthiophene (2MT)
50
0.021
3-methylthiophene (3MT)
50
0.021
2,5-dimethylthiophene (2,5-DMT)
50
0.021
Benzothiophene (BT)
60
0.025
Solvent
Iso-octane
99.893
[0000]
TABLE 3
Capacity: mg-
Capacity: mg-
S/Ads.-g
S/Ads-g
Cycles
Sample
(<1 ppmw)
(<30 ppmw)
1 st
Fresh
2.8
2.8
2 nd
Reg. @ 375° C., 2 h
2.7
2.7
3 rd
Reg. @ 375° C., 2 h
2.4
2.9
EXAMPLE 14
Manufacture of Ti 0.5 Ce 0.5 O 2 Adsorbent
[0194] Urea in an amount of 75 g is placed in a glass beaker, and 800 ml deionized water is added to make 800 ml of 1.56 M aqueous urea solution.
[0195] 32.9 g of 99.99% pure ammonium cerium nitrate from Aldrich is dissolved in deionized water to make 100 mL of 0.60 M ammonium cerium nitrate solution.
[0196] 18.0 g of synthesis grade titanium oxysulfate-sulfuric acid complex hydrate from Aldrich is dissolved in deionized water over a period of 1.5 hours to make 100 mL of 0.60 M titanium oxysulfate-sulfuric acid complex hydrate solution.
[0197] 100 mL of the titanium oxysulfate-sulfuric acid complex hydrate solution is mixed with 100 mL of the ammonium cerium nitrate solution to form a first solution.
[0198] All of the first solution is mixed with 800 ml of the aqueous solution and vigorously mixed by magnetic stirrer to produce a mixed solution. The mixed solution is heated at 2° C./min to 90° C., maintained at 90° C. for 8 hours to produce precipitates, and cooled at 10° C./min to room temperature to produce a cooled slurry solution.
[0199] The cooled slurry solution is filtrated to separate precipitates. The precipitates are dried at 100° C. under air flow to produce dried precipitates. The dried precipitates are calcined in air flowing at 100 mL/min flow while heating at 1.5° C./min to 450° C. The precipitates are maintained at 450° C. for 6 hours to yield Ti 0.5 Ce 0.5 O 2 adsorbent.
EXAMPLE 15
Manufacture of Ti 0.9 Ce 0.1 O 2 Adsorbent
[0200] Urea in an amount of 75 g is placed in a glass beaker, and 800 ml deionized water is added to make 800 ml of 1.56 M aqueous urea solution. 8.22 g of 99.99% pure ammonium cerium nitrate from Aldrich is dissolved in deionized water to make 100 mL of 0.149 M ammonium cerium nitrate solution.
[0201] 32.7 g of synthesis grade Titanium oxysulfate-sulfuric acid complex hydrate from Aldrich is dissolved in deionized water over a period of 1.5 hours to make 100 mL of 1.215 M Ti oxysulfate-sulfuric acid complex hydrate solution.
[0202] 100 mL of the titanium oxysulfate-sulfuric acid complex hydrate solution is mixed with 100 mL of the ammonium cerium nitrate solution to form a first solution. All of the first solution is mixed with 800 ml of the urea aqueous solution and vigorously mixed by magnetic stirrer to produce a mixed solution.
[0203] The mixed solution is heated at 2° C./min to 90° C., maintained at 90° C. for 8 hours to produce precipitates, and then cooled at 10° C./min to room temperature to produce a cooled slurry solution. The cooled slurry solution is filtrated to separate precipitates. The precipitates are dried at 100° C. under air flow to produce dried precipitates. The dried precipitates are calcined in air flowing at 100° C. mL/min flow while heating at 1.5° C./min to 450° C. The precipitates are maintained at 450° C. for 6 hours to yield Ti 0.9 Ce 0.1 O 2 adsorbent.
[0204] The adsorption capacities of the adsorbents of examples 9, 14 and 15 are evaluated in the fixed-bed flow system. The adsorption is conducted at room temperature and 1.2 h −1 of LHSV using a light JP-8 fuel, which contains 373 ppmw of sulfur compounds, mainly alkylated benzothiophenes. The adsorptive breakthrough capacities of the adsorbents at sulfur levels of 1 and 30 ppmw, respectively, are shown in Table 4.
[0000]
TABLE 4
Capacity: mg-S/
Capacity: mg-
Ads.-g
S/Ads.-g
Example
Adsorbent
Fuel
(<1 ppmw)
(<30 ppmw)
9
Ti 0.1 Ce 0.9 O 2
Light JP-8
0.04
0.23
14
Ti 0.5 Ce 0.5 O 2
Light JP-8
0.31
0.85
15
Ti 0.9 Ce 0.1 O 2
Light JP-8
2.01
3.26
[0205] For comparison of performance of the novel adsorbents with known metal oxide adsorbents, all of the adsorbents, before evaluation, are dried in an oven at 100° C. overnight. Then, 5 g of model fuel (III) having the composition shown in Table C is poured into a glass vial having 0.5 g of the adsorbent. Adsorption is conducted under stirring for 120 min. at room temperature and ambient pressure. After adsorption, the treated fuel is filtered, and total sulfur concentration in the treated fuel is analyzed by an ANTEK 9000 Total Sulfur Analyzer. This procedure is repeated three times for each adsorbent. The average of the results for each adsorbent is shown in Table 5.
[0000]
TABLE C
Model fuel (III) composition
S conc.
Mol conc.
Mol conc.
Compound
(ppmw)
(mmol/kg)
(mmol/L)
Sulfur
Tetrahydrothiophene (THT)
106.7
3.333
2.543
Benzothiophene (BT)
100.8
3.149
2.403
2-methyl benzothiophene (2MBT)
105.6
3.299
2.517
Dibenzothiophene (DBT)
100.4
3.137
2.393
4,6-dimethyl benzothiophene
100.5
3.140
2.396
(4,6DMDBT)
Aromatics
Naphthalene (Na)
3.148
2.402
1-methyl naphthalene (1MNa)
3.211
2.450
Phenanthrene (PNT)
3.138
2.394
Olefin
1-C 8
3.204
2.445
Internal standard (IS)
n-C 10
3.338
2.547
Solvent
n-C 14 + n-C 12
—
—
[0000]
TABLE 5
Adsorbents
Capacity (mg-S/g-Ads.)
MgO
4.22
CaO
0.48
SrO
0.71
Y 2 O 3
0.01
La 2 O 3
0.06
TiO 2
0.14
ZrO 2
0.30
V 2 O 5
1.31
Nb 2 O 5
0.03
CrO 3
1.27
Cr 2 O 3
3.37
MoO
0.37
WO 2
0.19
MnO
0.04
Fe 2 O 3
0.71
RuO 2
2.44
CoO
0.80
NiO
1.69
PdO
1.78
CuO
0.39
Ag 2 O
0.24
ZnO
0.14
Al 2 O 3
5.04
Ga 2 O 3
0.0
PbO
0.06
Bi 2 O 3
0.05
Ti 0.9 Ce 0.1 O 2 .*
7.32
*Adsorbent of Example 15
EXAMPLE 16
Manufacture of Ti—Ce—Al—O Adsorbent
[0206] Urea in an amount of 60.00 g is transferred to a glass beaker; deionized water in an amount of 500 mL is added to make 500 mL of 1.998 M aqueous urea solution.
[0207] 32.32 g of synthesis grade titanium oxysulfate-sulfuric acid complex hydrate from Aldrich is mixed with 100 ml deionized water to form a 1.077M titanium oxysulfate-sulfuric acid complex solution.
[0208] 6.58 g of 99.9% pure ammonium cerium nitrate from Aldrich is mixed with 100 ml deionized water to make 100 mL of 0.120 M ammonium cerium nitrate solution.
[0209] 10.04 g of 98% pure aluminum nitrate nonahydrate from Aldrich is mixed with 100 ml deionized water to make 100 ml of 0.262 M aluminum nitrate nonahydrate solution.
[0210] All the titanium oxysulfate-sulfuric acid complex solution, ammonium cerium nitrate solution and aluminum nitrate nonahydrate solution are mixed with 500 ml of the aqueous urea solution for form a mixed solution. Deionized water is added to the solution to achieve a total volume of 1000 mL of the solution, and stirred vigorously by magnetic stirrer.
[0211] The mixed solution then is heated at 2° C./min to a temperature of 95° C., maintained at 95° C. for 6 hours to produce precipitates, and then cooled at 1° C./min down to room temperature to produce a cooled slurry solution. The cooled slurry solution is filtrated to remove the precipitates. The precipitates then are dried at 110° C. in an oven under air flow to produce dried precipitates. After drying, the precipitates are calcined under 100 mL/min of air flow at a heating rate of 1° C./min to 500° C., and maintained at 500° C. for 4 hours to produce adsorbent. The composition of the adsorbent is shown in Table 6. The adsorbent has a particle size range of 0.1 micron to 30 micron, a pore size range of 0.001 micron to 0.01 micron, and a porosity of 10 vol. % to 70 vol. %.
EXAMPLE 17
Manufacture of Ti—Ce—Al—Ag—O Adsorbent
[0212] Urea in an amount of 60.00 g is transferred to a glass beaker; deionized water in an amount of 500 mL is added to make a 1.998 M aqueous urea solution.
[0213] 32.32 g of synthesis grade titanium oxysulfate-sulfuric acid complex hydrate from Aldrich is mixed with 100 ml deionized water to form a 1.077M titanium oxysulfate-sulfuric acid complex hydrate solution.
[0214] 6.58 g of 99.9% pure ammonium cerium nitrate from Aldrich is mixed with 100 ml deionized water to make 100 mL of 0.120 M ammonium cerium nitrate solution.
[0215] 10.04 g of 98% pure aluminum nitrate nonahydrate from Aldrich is mixed with 100 ml deionized water to make 100 ml of 0.262M an aluminum nitrate solution.
[0216] 4.95 g of 99% pure silver nitrate from Aldrich is mixed with 100 ml deionized water to make 100 mL of 0.288M silver nitrate solution.
[0217] All the titanium oxysulfate-sulfuric acid complex solution, ammonium cerium nitrate solution, aluminum nitrate solution and silver nitrate solutions are mixed with 500 ml of the urea solution to make a reaction solution. Deionized water is added to the reaction solution to achieve a total volume of 1000 mL of reaction solution, and stirred vigorously by magnetic stirrer.
[0218] The reaction solution then is heated at 2° C./min to a temperature of 95° C., maintained at 95° C. for 6 hours to produce precipitates, and then cooled at 10° C./min to room temperature to produce a cooled slurry solution.
[0219] The cooled slurry solution then is subjected to filtration to remove the precipitates. The precipitates then are dried at 110° C. in an oven under air flow to produce dried precipitates. The dried precipitates are calcined under 100 mL/min of air flow at a heating rate of 1° C./min to 500° C., and maintained at 500° C. for 4 hours to produce adsorbent. The composition of the calcined precipitates is shown in Table 6. The adsorbent has a particle size range of 0.1 micron to 30 micron, a pore size 0.001 micron to 0.1 micron, and a porosity of 10 vol. % to 70 vol. %.
[0000]
TABLE 6
Metal oxide weight percentage (wt %)
Adsorbent
Ag 2 O
Al 2 O 3
TiO 2
CeO 2
Example 15
80.7
19.3
Example 16
11.1
71.7
17.2
Example 17
21.7
8.7
56.1
13.5
[0220] The sulfur adsorption capacities of the fresh adsorbents and regenerated adsorbents of examples 15-17 are evaluated by the batch system. Adsorption by the batch system entails first heating the adsorbent from room temperature to 300° C. at 1.5° C./min in an oven, maintaining the adsorbent at 300° C. for 2 hours, and cooling to room temperature at 10° C./min to produce a pretreated adsorbent.
[0221] Model fuel (IV) having the composition shown in Table D is added to the pretreated adsorbent and placed into a batch adsorption reactor. The adsorbent is stirred in the fuel for 2 hours at room temperature and ambient atmosphere. The resulting treated fuel and adsorbent are separated from each other by centrifuge.
[0222] The treated fuel is analyzed by an HP 5890 gas chromatograph with a flame ionization detector (FID) and an Antek 9000S total sulfur analyzer. The spent adsorbent is regenerated in an oven in the air flowing at the rate of 80 mL/min while heating the adsorbent from room temperature to 500° C. at 2° C./min and then maintaining the adsorbent at 500° C. for 4 hours to produce regenerated adsorbent. The adsorbent then is cooled to room temperature under the air flow.
[0223] The adsorptive capacities of the fresh and regenerated adsorbents are shown in Table 7. The spent adsorbents are regenerated by increasing the adsorbent-bed temperature to 500° C. at 5° C./min and maintaining at 500° C. for 2 hours under an airflow rate of 20 ml/min. The adsorptive capacities of the regenerated adsorbents treated according to this procedure are also shown in Table 7 with the symbol*.
[0000]
TABLE D
Model fuel (IV) composition
Molar
Purity
Concentration
concentration
Chemicals
(g/g)
wt. %
ppmw S
(mmol/kg)
Sulfur compounds
0.99
0.03
105
3.3
Tetrahydrothiophene
Benzothiophene
0.99
0.04
100
3.1
2-MBT
0.97
0.05
100
3.1
DBT
0.98
0.06
100
3.1
4,6-DMDBT
0.97
0.07
100
3.1
Total
505
Aromatics
Naphthalene
0.99
0.04
3.1
1-
0.97
0.04
3.1
Methylnaphthalene
Phenanthrene
0.98
0.06
3.1
Olefin
1-Octene
0.98
0.04
3.1
Alkanes
n-Dodecane
0.99
0.05
3.1
n-Decane
0.99
49.76
n-Hexadecane
0.99
49.76
Total
100.00
[0000]
TABLE 7
Sulfur adsorptive capacity (mg-S/g-Ads.)
Regen.-
Regen.-
Adsorbents
Fresh
1st
Regen.-2nd
Regen.-3rd
4th
Example 16
3.6
1.6*
1.7*
1.4*
3.4
Example 17
4.1
4.0
3.8
3.7
*The adsorbents are regenerated from room temperature to 500° C. at a temperature ramp of 5° C./min and keep final temperature for 2 hours. The air flow rate of 20 ml/min is used.
[0224] The adsorption capacities of the adsorbents of examples 15, 16 and 17 for real fuel JP-5 with 1040 ppmw of sulfur also are evaluated in the batch system described above. The adsorptive capacities of the adsorbents are shown in Table 8.
[0000]
TABLE 8
Adsorbents
Sulfur adsorptive capacity (mg-S/g-Ads.)
Example 15
0.8
Example 16
1.8
Example 17
5.7
[0225] The adsorption capacities of the adsorbents of examples 15, 16 and 17 for real fuel JP-5 with 1040 ppmw of sulfur are also evaluated in the fixed-bed flow system. The adsorption is conducted at room temperature and 1.2 h −1 of LHSV. The adsorptive capacities of the adsorbents at different breakthrough sulfur levels are shown in Table 9.
[0000]
TABLE 9
Sulfur adsorptive capacity (mg-S/g-Ads.)
5 hours
Adsorbent
<1 ppmw*
<10 ppmw*
<30 ppmw*
adsorption
Example 15
0.90
1.77
2.20
4.96
Example 16
2.03
3.47
3.82
6.93
Example 17
0.30
1.50
2.10
5.09
*The breakthrough sulfur level | Compositions and processes are disclosed for removing sulfur and sulfur compounds from hydrocarbon fuel feedstocks. The feedstock is contacted with a regenerable sorbent such as a compound of the formula Ti x Ce y O 2 where 0<x/y≦1 and where 0<x≦1 and 0<y≦1 capable of selectively adsorbing sulfur compounds present in the hydrocarbon feedstock at about 0° C. to about 100° C. such as at about 25° C. | 2 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to adaptive information compression. More specifically, the present invention relates to the compression of bandwidth in order to recreate active portions of the bandwidth at a remote location.
2. Background Information
Commercial services such as radiotelephone and television require the use of expensive transmitters or base stations to provide coverage for their target areas. Remote locations, such a rural areas, sometimes have difficultly receiving such signals due to their distance from the nearest transmitter or due to elements of their terrain (such as a mountain range).
In addition, with respect to radiotelephone coverage, certain public events, such as stadium events, can cause a temporary sharp increase in demand for available channels.
The cost of building additional transmitters and base stations in order to provide service to remote areas, poor signal areas, or temporary increased demand areas is not always cost effective. Therefore, there is a need for a low cost system and method that can provide signal coverage for these aforementioned areas.
One solution is to sample the entire relevant frequency band from a given signal area and using a fiber-optic cable, transport the entire spectrum to a target location where the entire spectrum is retransmitted. This solution is expensive, requires a large storage capability, and uses excessive processing time, since for example, the necessary bandwidth could be on the order of 25 MHz or more, thus requiring large storage space. In addition, because the above solution uses fiber-optic cable, the above system and method would not be feasible for temporary use.
Therefore, there is a need for a low cost system and method that can provide signal coverage for remote areas, poor signal areas, and temporary areas, without the need to process and transport a signal having a large bandwidth.
SUMMARY OF THE INVENTION
The present invention is directed to conserving information bandwidth or storage space by compressing underutilized information present in a wide-band signal into a much narrower maximum utilized information band signal. This is achieved by obtaining a spectral concentration map of an input wide-band signal by transforming the wide-band signal into the frequency domain and de-selecting the data space where there is substantially little spectral activity. A narrow-band signal is created by reformatting the remaining data space into a contiguous narrow-band signal. Finally, the original time-domain image of the data, which has the inactive spectra removed, is reconstructed from the narrow-band signal, thus allowing the total time-domain bandwidth to be significantly less than the original.
BRIEF DESCRIPTION OF THE DRAWINGS
Other objects and advantages of the present invention will become apparent to those skilled in the art from the following detailed description of exemplary embodiments, when read in conjunction with the accompanying drawings wherein like elements have been designated with like reference numerals and wherein:
FIG. 1 illustrates an exemplary block diagram of an embodiment of the present invention;
FIG. 2 illustrates an exemplary embodiment of the selection and storage stage of the present invention;
FIG. 3 illustrates an exemplary embodiment of blocks 106 and 108 of FIG. 1 ; and
FIG. 4 illustrates an exemplary embodiment of the present invention which recovers individual channels from a contiguous band.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 illustrates a block diagram of an exemplary embodiment of the present invention. In block 102 , uncompressed digitized data representing a wide-band signal in the time domain 100 is transformed to the frequency domain. In block 104 , the frequency domain signal is broken down into segments which represent the width of a channel, e.g., a 30 kHz segment for a cellular radio telephone. Each segment is evaluated to determine if the segment contains active spectrum. Active spectrum is defined as spectrum which contains an energy or power level higher than a predetermined threshold. One skilled in the art will readily appreciate that the appropriate predetermined threshold will vary based on the actual use of the present invention for a given environment. That is, the sensitivity of the evaluation will relate to the expected energy levels or signal strengths common to the type of signal or spectrum which is being compressed by the present invention, e.g., cellular telephone, trunked radio, television, radio, etc.
The active segments are then reformatted into a contiguous order in a narrow-band signal (i.e., a smaller band than the uncompressed digitized data 100 ) in block 106 . The frequency domain narrow-band signal is then transformed to the time domain in block 108 which provides a compressed digitized narrow-band signal in the time domain 110 .
FIG. 2 illustrates an exemplary embodiment of the selection and storage stage of the present invention which corresponds to blocks 102 and 104 in FIG. 1 . The following discussion is framed in the context of a cellular radiotelephone system using the Advanced Mobile Phone Service (AMPS) standard. The AMPS system uses ordinary FM modulation and frequency-division multiple access (FDMA). Those skilled in the art will recognize that the principals disclosed herein are applicable to other radio environments, such as trunked radio, television, radio, etc.
The AMPS standard for a cellular radiotelephone system uses 416, 30 kHz channel pairs allocated to a 25 MHz portion of the UHF band. If the 416 channel pairs were contiguous, then the bandwidth required by the channel pairs would only be 12.48 MHz. However, since the 416 available channel pairs are not contiguous, in order to access all of the available channels, the full 25 MHz portion of the UHF band must be processed.
In an exemplary embodiment of the present invention, the 25 MHz portion is first selected and then translated to baseband using a conventional complex demodulator so that the band of interest occupies the spectral region from 0 to 25 MHz, positive frequencies only. The translated 25 MHz portion is then passed through an analog-to-digital (A/D) converter 214 that, for example, produces complex samples having a sample rate of 30.72 MHz. A/D conversion is well-known in the art and is described, for example, in U.S. Pat. No. 4,831,382, the disclosure of which is hereby incorporated by reference.
The digitized signal is then provided as an input to a Fast Fourier Transform (FFT) module 216 . Fast Fourier Transforms are well-known in the art and are described, for example, in U.S. Pat. No. 6,081,821, the disclosure of which is hereby incorporated by reference. One skilled in the art will recognize that the FFT module can be replaced with modules that implement other conventional algorithms which efficiently compute the Discrete Fourier Transform (DFT) of signal data or images, such as a prime factor algorithm (e.g., the Good algorithm) or the Winograd algorithm. The exemplary FFT module 216 produces a spectral estimate by forming a 1024 point FFT for each channel. The 1024 points correspond to a time record of 33.3 μs and a spectral resolution of 30 kHz, the bandwidth of the exemplary AMPS channel. The FFT module 216 produces 128 consecutive complex samples which, for example, takes 4.267 milliseconds at the aforementioned sample rates.
In an exemplary embodiment of the present invention, FFT 216 includes an 80 dB Dolph-Chebyshev weighting on the input data to prevent spectral leakage from producing an unacceptable level of cross-talk or adjacent channel interference. In this exemplary embodiment, the input signals are multiplied by the 80 dB Dolph-Chebyshev weighting function prior to transformation into the frequency domain by FFT 216 . Dolph-Chebyshev weighting functions are well-known in the art and are described, for example, in U.S. Pat. No. 5,491,727, the disclosure of which is hereby incorporated by reference. When an 80 dB Dolph-Chebyshev weighting is used on signals input to FFT 216 , greater than 60 dB of spectral leakage interference rejection is achieved in any channel situated more than three channels removed from any occupied channel. However, those of ordinary skill in the art will recognize that Dolph-Chebyshev weighting functions at different amplitude levels can be used. In addition, windowing functions other than Dolph-Chebyshev can also be used, such as Hamming, Taylor, and Gaussian.
The 128 consecutive complex samples taken from the FFT module 216 produce a 128-point frequency domain signal for each of the 416 channels. The frequency domain signals for each of the 416 channels are then stored in memory module 222 . Memory module 222 can be comprised of, for example, commercially-available random access memory. However, those of ordinary skill in the art will recognize that other forms of memory can be used for memory module 222 , such as commercially-available hard-disk drives. In addition, at the same time the 128 consecutive complex samples for each channel are stored in the memory module 222 , the samples are also provided to a power calculation module 218 . Power calculation module 218 converts the 128 consecutive complex samples for each channel into a power spectrum by, for example, computing the square magnitude for each channel and averaging the 128 consecutive power spectra to form a single power spectral estimate. The power spectral estimate for each channel is then provided to the select module 220 .
The select module 220 compares the power spectral estimate for each channel with a threshold value to determine which channels are active, i.e., in use, and which are inactive. Once an active channel is found, the select module 220 informs memory module 222 of the existence of the active channel.
In an alternate exemplary embodiment of the present invention, the power calculation module 218 and the select module 220 can be replaced by other determination modules which use criteria other than power to select the active channels. For example, the active channels may already be known to the system and/or a data signal can be provided from an external source which identifies which channels are active.
After all of the active channels have been identified by select module 220 , memory module 222 then provides the 128 consecutive complex samples for each active channel 224 to block 106 (see FIG. 1 ) which produces a contiguous frequency domain composite signal. In an exemplary embodiment of the present invention, the composite signal also includes mapping data produced by the memory module 222 that indicates the original frequency assignments for each of the active channels so that the original wide-band spectrum can be reproduced from the composite signal. Alternatively, the mapping data can be contained in a separate signal and can be produced, for example, by the power calculation module 218 , the FFT 216 , or the A/D converter 214 .
FIG. 3 further illustrates blocks 106 and 108 of FIG. 1 . For simplification purposes only, it is assumed that up to 16 channels were selected by the select module 220 (see FIG. 2 ). However, those of ordinary skill in the art will recognize that any number of channels can be selected by select module 220 . 16×30 kHz channels will require a total of 480 kHz, therefore the present invention reorganizes the 16 channels present in the 0–25 MHz band into a contiguous 0–480 kHz frequency band. The reorganization can be accomplished by zero-filling (i.e., padding with zeroes at the end of each of the signals) each of the selected 128-point frequency domain signals 328 from the memory module 222 using zero fill module 330 to create a 2048 point frequency domain signal. The 2048-point zero-padded frequency domain signals are then converted back into the time domain using inverse FFT (IFFT) module 332 . Inverse FFTs are well-known in the art and are described, for example, in the above-incorporated U.S. Pat. No. 6,081,821. Zero fill module 330 and IFFT module 332 effectively resample each of the selected time domain signals from the 30 kHz sampling rate to a 480 kHz sampling rate. Following the effective resampling, each selected channel is translated to a unique and non-overlapping 30 kHz section of the 480 kHz band. The translation is effected by multiplying the resampled signals by the appropriate complex sinusoid 334 :
y ( n ) = x ( n ) ⅇ j2 π f k n f s n = 0 , 1 , … , 2047
where y(n) is the modulated signal, x(n) is the time domain signal, f k is the translation frequency, e.g., 0 kHz–450 kHz, and f s is the sampling rate, e.g., 480 kHz.
The modulated signals for each of the 16 channels are added together in sum module 336 which produces a contiguous 480 kHz band 338 of 16×30 kHz channels.
The contiguous band can then be transported to a remote location so that the channels can be extracted and remodulated using their original frequencies. Using this technique, for example, a cellular base station can be extended to cover a remote area by transporting the contiguous band and retransmitting the channels of the base station in the remote area without the need for building a new base station. Since the contiguous band has a significantly smaller bandwidth than the total possible bandwidth of a base station (e.g., 480 kHz vs. 25 MHz) the resources needed to transport the effective bandwidth are greatly reduced. The contiguous band can be transported using any known transmission medium such as, fiber, coax, microwave link, satellite link, etc.
FIG. 4 illustrates an exemplary embodiment of the present invention which recovers the individual channels from the contiguous band. As stated above with reference to FIG. 3 , the contiguous band is made up of 2048 complex samples representing 0–480 kHz having a sample rate of 480 kHz. Data blocking module 440 divides the 2048 complex values into 128 blocks of 16 samples each. Each 16-sample block is weighted with, for example, a 16-point 80 dB Dolph-Chebyshev weight and input to the FFT 442 . The FFT 442 converts each 16-sample block into 16 channels 444 , each channel 444 having bandwidth of 30 kHz. The successive 128 blocks are converted by the FFT 442 into 128 frequency domain samples in each channel 444 . Each 30 kHz frequency domain channel 444 is then re-modulated to its original frequency using conventional digital-to-analog (D/A) conversion and frequency translation techniques so that a cellular radiotelephone user present in a remote location would be able to use a base station (or neighboring base station) without the need for additional equipment. D/A conversion is well-known in the art and is described, for example, in U.S. Pat. No. 6,140,953, the disclosure of which is hereby incorporated by reference. Frequency translation is also well-known in the art and is described, for example, in U.S. Pat. No. 4,316,282, the disclosure of which is hereby incorporated by reference.
It will be appreciated by those skilled in the art that the present invention can be embodied in other specific forms without departing from the spirit or essential characteristics thereof, and that the invention is not limited to the specific embodiments described herein. The presently disclosed embodiments are therefore considered in all respects to be illustrative and not restrictive. The scope of the invention is indicated by the appended claims rather than the foregoing description, and all changes that come within the meaning and range and equivalents thereof are intended to be embraced therein. | An adaptive information compression system and method conserves information bandwidth or storage space by compressing underutilized information present in a wide-band signal into a much narrower maximum utilized information band signal. This is achieved by obtaining a spectral concentration map of an input wide-band signal by transforming the wide-band signal into the frequency domain and de-selecting the data space where there is substantially little spectral activity. A narrow-band signal is created by reformatting the remaining data space into a contiguous narrow-band signal. The original time-domain image of the data, which has the inactive spectra removed, is reconstructed from the narrow-band signal, thus allowing the total time-domain bandwidth to be significantly less than the original. | 7 |
BACKGROUND OF THE INVENTION
The present invention relates to a gas detecting sensor for detecting the partial pressure of oxygen gas contained within exhaust gases discharged from an internal combustion engine and measuring air/fuel ratio of the combustion mixture to be supplied into the internal combustion engine.
Recently, "lean burn system" that is, the system of operating an internal combustion engine with an air/fuel ratio larger than the stoichiometric value thereof, is proposed and employed in practice in order to reduce harmful components contained within the exhaust gases and lower the fuel consumption.
The above described "lean burn system" requires a detecting means for accurately detecting air/fuel ratio in a range of lean mixtures.
U.S. Pat. Nos. 3,933,028 and 4,012,709 show examples of such a detecting sensor as described above.
These detecting sensors are provided with a sensing element made of cobalt monoxide (CoO) or an alloy of cobalt monoxide (CoO) and magnesium oxide (MgO). These detecting sensors are further provided with a heating means for heating and maintaining the sensing element at a predetermined temperature, for example 900° C. in order to prevent cobalt monoxide from changing into tricobalt tetroxide (Co 3 O 4 ) and to compensate output fluctuation caused by the temperature change.
These conventional detecting sensors have problems as follows.
Since the heating coil is used for heating the sensing element, the structure of the sensor becomes complex and it is troublesome to mount the sensor to the exhaust pipe.
Since the sensing element is formed into a cylindrical or disc-shaped block and the heating coil is arranged around the housing which supports the sensing element, the device becomes large.
Since the sensing element is thick, the sensing element does not exhibit excellent responsive characteristic to the change of the partial pressure of oxygen gas.
Since the sensing element which is supported within the housing, is not directly contacted with the heating coil which is arranged around the housing, high heating efficiency is not obtained so that it takes a while for heating the sensing element to a predetermined temperature and that the consumption of electric power becomes large.
Accordingly, one object of the present invention is to provide a compact gas detecting sensor having simple construction of which sensing element exhibits excellent responsive characteristic.
Another object of the present invention is to provide an improved gas detecting sensor which can be produced with high working efficiency.
DESCRIPTION OF THE DRAWINGS
Other objects and advantages of the invention will become apparent from the follwing description of embodiments with reference to the accompanying drawings wherein:
FIG. 1 is a sectional veiw of a gas detecting device wherein a gas detecting sensor of the present invention is accomodated;
FIG. 2 is a perspective view of the sensor of a first embodiment;
FIG. 3 to FIG. 6 are views showing the process of producing the sensor of a first embodiment;
FIG. 7 to FIG. 9 are views showing the arrangement of electrodes and lead wires in sensors of a second to a fourth embodiments of the present invention, respectively;
FIG. 10 to FIG. 13 are views showing the steps for producing a sensor of a fifth embodiment;
FIG. 14 is a plane view of a sensor of a sixth embodiment; and
FIG. 15 is an end view of the sensor of the sixth embodiment.
SUMMARY OF THE INVENTION
The gas detecting sensor of the present invention is provided with a base member which also operates as a heating means, electrodes formed on the base member and a sensing element formed on the base member so as to be contacted with the electrodes. The base member is made of ceramic materialwhich generates heat when an electric current is supplied thereto.
According to the present invention, since the base member on which the sensing element is formed, also operates as the heating means, the structure of the sensor can be made simple and the size thereof can be made small.
Since the sensing element is formed like a film, the sensing element exhibits excellent responsive characteristic.
And since the sensing element is formed on the base member which also operates as a heating means, heating efficiency can be made high.
Furthermore, according to the present invention, a gas detecting sensor canbe easily produced by printing the materials for the electrodes and the sensing element on the surface of the ceramic base member and sintering together.
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be explained in detail in accordance with several embodiments with reference to the accompanying drawings.
FIG. 1 and FIG. 2 show a first embodiment of the present invention.
In the first embodiment, the gas detecting sensor S comprises a plate shaped base body 2, one pair of electrodes 3c which are continuously formed along both side edges of the upper surface of the base body 2 and on both side surfaces of the top end portion thereof for supplying electric current to the base body 2, a film shaped sensing element 1 whichis formed on the top end portion of the surface of the base body 2 so as tobe electrically insulated therefrom, another pair of electrodes 3e which are formed on the surface of the base body 2 so as to be electrically insulated therefrom, one end of which is connected to the sensing element 1, respectively, lead wires 3a and 3d which are connected to the electrodes 3c and 3e, respectively, and an insulating layer covering the electrodes 3e.
The base body 2 is made of ceramic material which generates heat when an electric current is supplied thereto, such as silicon carbide, lanthanchromite, silicon nitride and titanium carbide.
The sensing element 1 is made of ceramic material of which electric resistance changes in accordance with the change of the partial pressure of oxygen gas, such as cobalt monoxide, titanium oxide, nickel monoxide, zirconium oxide, tin oxide and zinc oxide.
The electrodes 3c and 3e are made of platinum, platinumrhodium alloy or thelike.
The insulating layer is made of alumina, spinel, mullite or the like.
The base body 2 is accomodated within a protecting cover member 9 made of heat resistant metal and provided with holes 9a for introducing exhaust gases therein, and a pipe member 10 connected to the cover member 9. In the connecting portion of the protecting cover member 9 and the pipe member 10, a flange member 11 for fixing the cover member 9 and the pipe member 10 to an exhaust pipe (not shown) is mounted.
The sensor S is supported by a retaining member 6 made of a sintered body such as alumina within the pipe member 10. And to the base end portion of the base body 2, the lead wires 3a and 3d and the sub lead wires 5 which are connected to the lead wires 3a and 3d are fixed within the pipe member10 by means of inorganic binding agent 7.
To the pipe member 10, pipe members 13 and 14 are connected in order. Within the pipe members 13 and 14, an insulating pipe 8 made of alumina orthe like, a bush 12 made of fluorine-contained rubber or the like and a heat resistant rubber member 15 made of silicon rubber or the like are accomodated and the sub-lead wires 5 are inserted therethrough and extendsoutside the pipe member 14 with being covered by a covered member 16.
Hereinafter, the structure of the detecting sensor S of the present invention will be explained together with the producing steps thereof withreference to FIGS. 3 to 6.
As shown in FIGS. 3A, 3B and 3C, on the upper surface of the sintered ceramic base plate 2, insulating layers 4a made of alumina paste or the like are printed along both side edges thereof so as to extend in the longitudinal direction thereof and dried. Then, one portion 3c 1 of each electrode 3c is printed on each insulating layer 4a. And on each sidesurface of the top end portion of the base plate 2, the other portion 3c 2 of each electrode 3c is printed so as to continue from one portion 3c 1 of each electrode 3c.
Next, as shown in FIGS. 4A and 4B, on the whole surface of the base plate 2, on which one electrode portion 3c 2 are formed, an insulating layer4b made of alumina paste or the like is printed except for the base end portion (righthand portion in FIG. 4A) of each of one electrode portion 3c 1 .
After the insulating layer 4b is dried, a pair of electrodes 3e are printedin the central portion of the surface of the insulating layer 4b. Then, theobtained base plate on which the insulating layers and the electrodes are printed is sintered at 1500° to 1600° C. for about 5 hours.
Then, as shown in FIGS. 5A and 5B, the vase end portion of each of the electrodes 3c 1 and 3e is coated with nickel and lead wires 3a and 3d are copper-soldered thereto, respectively. And the surface of the base plate 2 except for the top end portion thereof is covered with electric insulating material such as the paste of glass matter so as to completely cover the electrodes 3c 1 and 3e to form a protecting layer 4c.
Next, as shown in FIGS. 6A and 6B, on the surface of the top end portion ofthe base plate 2 on which the protecting layer 4c is not formed, paste likecobalt monoxide (CoO) is printed so as to cover the end of each of the electrodes 3e and sintered at 800° C. for about 1 hour to form a sensing element 1.
In FIGS. 3B, 4B, 5B and 6B, each of the electrodes 3c 1 , 3c 2 , and 3e and the insulating layers 4a, 4b and 4c is drawn thicker than the actual thickness thereof in order to clarify the structure thereof.
In the detecting sensor produced by the above described producing steps, the base plate 2 which supports the sensing element 1 also operates as theheating means. When the electric current is supplied to the base plate 2 through the lead wires 3a and the electrodes 3c 1 , the temperature of the top end portion of the base plate 2 to which the sensing element 1 is fixed, rapidly rises so that large electric consumption is not required for heating the sensing element 1.
Since the sensing element 1 is formed into a thin film, the exhaust gases diffuse within the sensing element 1 for a very short time so that excellent responsive characteristic can be obtained.
Furthermore, since the electrodes 3c 1 and 3e which are fixed to the upper surface of the base plate 2 are completely covered with the protecting layer 4c and the sensing element 1, short circuit which would occur between the electrodes 3c and 3e when electric-conductive substance such as carbon contained within the exhaust gases is accumulated therebetween, can be prevented.
The electrodes for supplying an electric current to the base body can be modified into various forms due to the resistance value of the base body, electric power, heating temperature, etc.
In the second embodiment shown in FIG. 7, electrodes 3c are formed in nearly whole width of each of the top and base ends of the base plate 2. One of the electrodes 3c is connected to one of lead wires 3a through a longitudinally extending portion 3c 1 thereof which is formed along one of the side edges of the base plate 2 while the other electrode 3c is connected to the other lead wire 3a. In the gas detecting sensor of the second embodiment, the whole of the base plate 2 is heated.
In the third embodiment shown in FIG. 8, the base plate 2 is formed into a U-shape and lead wires 3a are connected to two base ends of the base plate2. The gas detecting sensor of the third embodiment provided with the U-shaped base plate 2 does not require such insulating layers 4a as shown in FIG. 3.
In The fourth embodiment shown in FIG. 9, on the whole of the side surfacesof the base plate 2, electrodes 3c are formed and a lead wire 3a is connected to each end of the electrodes 3c.
FIGS. 10 to 13 show a fifth embodiment of the present invention. The structure of the gas detecting sensor of the fifth embodiment will be explained together with the producing method thereof.
A pair of semi-columnar base bodies 2a and 2b are made of ceramic material which generates heat by supplying electric current thereto.
As shown in FIG. 10, on the flat surface and one semicircular end surface of the base body 2a, insulating layers 4d and 4e are printed.
And as shown in FIG. 11, on the flat surface of the base body 2b, an insulating layer 4f is printed except for rectangular portions 21 whcih are formed in both sides of one end portion thereof. And also on one semicircular end surface of the base body 2b, an insulating layer 4h is printed.
Next, as shown in FIG. 12, on the flat surface of the base body 2b, electrodes 3f are printed along the side edges thereof. One end of each electrode 3f is located in each rectangular portion 21 and is printed on the base body 2 directly. And on the flat surface of the base body 2b, a pair of electrodes 3h are printed between the electrodes 3f, so as to extend on the side surface of the base body 2b on which the insulating layer 4h is formed. Then, the obtained base body 2b is sintered at 1500° C. to 1600° C. for about 5 hours.
Next, as shown in FIG. 13, on the flat surface of the base body 2b, the flat surface of the base body 2a is laid and the base bodies 2a and 2b areheated under pressure to form a columnar structure 2. At this time, the electrodes 3f and 3h are connected to lead wires (not shown), respectively.
At last, on one end surface of the structure 2 on which the electrodes 3h are formed, paste of cobalt monoxide is printed and sintered at about 800° C. for about 1 hour to form a sensing element 1.
FIGS. 14 and 15 show a sixth embodiment of the present invention. To the top end of a cylindrical supporting member 20, a disc-shaped base body 2 made of ceramic material which generates heat when electric current is supplied thereto, is adhered. On the surface of the base body 2, an insulating layer 4k is formed and on the surface of the insulating layer 4k, a sensing element 1 is formed. Within the base body 2, a pair of electrodes 3c which are connected to lead wires 3a, respectively are embedded. And also within the base body 2 and the insulating layer 4k, a pair of electrodes 3e are embedded so that one end thereof extends to the sensing element 1. The other end of each of the electrodes 3e is connectedto each of lead wires 3d, and the electrodes 3e is covered with an insulating layer 4n within the base body 2.
As described above, according to the present invention, the base member on which the sensing element is fomed, also operates as the heating means so that the structure of the sensor can be made simple and the size thereof can be made small.
Since the sensing element is formed on the base member which also operates as a heating means, like a film, the sensing element exhibits excellent responsive characteristic and high heating efficiency is obtained.
Furthermore, according to the present invention, a gas detecting sensor canbe easily produced by printing the materials for the electrodes and the sensing element on the surface of the ceramic base member and sintering together.
Having now fully described the invention, it will be apparent to one of ordinary skill in the art that many changes and modifications can be made thereto without departing from the spirit or scope of the invention as setforth herein. | A compact and high sensitive gas detecting sensor for detecting the partial pressure of oxygen gas in the exhaust gases of an internal combustion engine is disclosed. The sensor is provided with a sensing element made of the ceramic material having an electrical characteristic which varies in response to variations in the partial pressure of oxygen gas, such as CoO, a base member made of ceramic material having a characteristic of generating heat when an electric current is supplied thereto, such as silicon carbide. The sensing element is integrally fixed to the base member through an insulating layer made of ceramic material. To the base member, electrodes are connected for supplying an electric current thereto so that the base member is maintained at a predetermined temperature regardless of the temperature change of the exhaust gases. | 6 |
This application is a divisional of U.S. application Ser. No. 09/843,603, filed on Apr. 26, 2001 now abandoned.
FIELD OF THE INVENTION
The present invention relates to the surface treatment of pigments, particularly white pigments, to improve dispersibility in polymeric materials, processability, and performance characteristics of the pigments. The pigments are treated with an organosilicon compound having at least one functional group that is capable of reacting with an acid or an anhydride. More specifically, the present invention relates to polymeric compositions comprising the surface treated pigments of the present invention.
BACKGROUND OF THE INVENTION
The treatment of titanium dioxide pigments with organosilicon compounds to improve dispersibility in a polymer matrix is well known in the art. For instance, U.S. Pat. No. 4,061,503 to Berger et al. and U.S. Pat. No. 4,151,154 to Berger describe the treatment of particulate titanium dioxide to improve its dispersibility in a resin or plastic medium. The titanium dioxide contains on its surface a silane possessing at least two to about three hydrolyzable groups bonded to the silicon, and an organic group which contains a polyalkylene oxide group.
Further, U.S. Pat. No. 4,810,305 to Braun et al. discloses a modified hydrophobic pigment or filler containing 0.05 to 10 wt. % of an organopolysiloxane having improved dispersibility in synthetic resins. U.S. Pat. Nos. 5,607,994 and 5,631,310, both to Tooley et al., disclose white-pigmented polymers (particularly, polyolefins such as polyethylene) containing white pigments treated with at least one silane or a mixture of at least one silane and at least one polysiloxane to improve processability in compounding and to improve performance properties such as lacing resistance in a polymeric matrix, as well as other physical characteristics.
SUMMARY OF THE INVENTION
The present invention relates to a pigment surface treated with a silane having at least one functional group capable of reacting with acids and anhydrides. The surface treated pigment or extended white pigment can then be compounded with at least one polymeric material and at least one compatibilizer.
The silane of the present invention useful for surface treating the pigments or extended white pigments has the following general structure:
R x Si(R′) 4-x
wherein
R is a nonhydrolyzable functional group directly or indirectly bonded to the silicon atom such as epoxy, isocyanato, mercapto, and mixtures thereof;
R′ is a hydrolyzable group such as alkoxy, halogen, acetoxy or hydroxy or mixtures thereof; and
x is 1 to 3.
Preferably, the pigment or extended white pigment is titanium dioxide.
The compatibilizer has at least one group which is acidic, or is an anhydride thereof.
The resultant polymer composition may further comprise lubricants, as well as a variety of other conventional additives.
The silanized pigments of the present invention exhibit improved processability, lower viscosity, increased lacing resistance, improved dispersion in polymeric materials and excellent optical properties including improved whiteness and yellowness index over the untreated pigments. The polymeric compositions of the present invention may be used in an endless variety of articles and applications.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
In general, the present invention encompasses the whitening treatment of potentially any inorganic oxide particulate material, clays, pigments, extended white pigments, and so forth. These materials are typically from classes of materials referred to as fillers, pigments, and reinforcing materials such as inorganic particulate materials and fibers (such as glass fibers, aluminum fibers and steel fibers), and so forth. Such materials include aluminum trihydroxide, magnesium hydroxide, calcined clays, kaolin clays, nanoclays, brass (with an oxidized surface), copper metal (oxidized at its surface), aluminum metal (oxidized at its surface), iron or steel (oxidized at its surface), alumina, aluminum trihydrate, siliceous materials such as fumed silica, hydrated silica (precipitated silica), silica aerogels, silica xerogels, aluminum silicates, calcium magnesium silicate, asbestos, glass fibers, molecular sieves, Wallostonite, calcium carbonate, carbon black (including lamp black), titanium dioxide (including titanium dioxide which contains HCl soluble alumina and/or silica), calcium sulphate, magnesium sulfate, calcium carbonate containing a silica coating or agglomerated to silica, and the like. In particular, the present invention is especially useful for the surface treatment of white pigments or extended white pigments, and even more particularly for the surface treatment of titanium dioxide pigments.
The titanium dioxide, TiO 2 , pigments useful in the present invention generally are in the rutile or anatase crystalline form and are commonly made by either a chloride process or a sulfate process. The optimum average particle size can range from about 0.005 to about 1 micron. The TiO 2 pigments may also contain ingredients added thereto to further improve dispersibility characteristics or other properties such as durability.
It has been found that the silane treatment of this invention can be used not only for TiO 2 but also for so-called extended white pigments such as calcium carbonate.
Additives and/or inorganic oxides are commonly added to the pigments and include but are not limited to aluminum, silicon, tin, triethanolamine, trimethylolpropane, phosphates, and so forth. Such additives are known to one of skill in the art.
“Silanized TiO 2 ” is defined herein as TiO 2 treated with either at least one silane, or a mixture of at least one silane and at least one polysiloxane (collectively referred to herein as organosilicon compounds).
The silanes useful herein are those that have a functional group capable of reacting with anhydrides or acids, their hydrolyzates or condensates thereof. Examples of such silanes include those having epoxy, isocyanato, and mercapto groups. In preferred embodiments, the silanes have epoxy groups.
Suitable silanes have the following general formula:
R x Si(R′) 4-x
wherein
R is a nonhydrolyzable functional group directly or indirectly bonded to the silicon atom; R′ is a hydrolyzable group such as alkoxy, halogen, acetoxy, hydroxy or mixtures thereof; and x=1 to 3.
Examples of suitable silanes useful in carrying out the invention include but are not limited to γ-(3,4-epoxycyclohexyl)ethyltrimethoxysilane such as Silquest® A-186, γ-glycidoxypropyltrimethoxysilane such as Silquest® A-187, γ-Glycidoxypropylmethyldiethoxysilane such as Silquest® Y-15078, 2-(3,4-epoxycyclohexalethyltriethoxysilane such as Silquest® Y-11870), γ-isocyanatopropyltrimethoxysilane such as Silquest® A-1310, γ-mercaptopropyltrimethoxysilane such as Silquest® A-189, and so forth. All of the above mentioned Silquest® materials are available from Crompton Corporation of Greenwich, Conn. Preferably, the silanes utilized include Silquest® A-187, Silquest® Y-11870and Silquest® Y-15078.
The silanes of the present invention may be used in combination with a lubricant including, but not limited to, polysiloxanes, silicone fluids, stearates, paraffin oils, fluorocarbon lubricants, and so forth. The polysiloxanes useful herein include polydimethylsiloxane and organomodified polydimethylsiloxane. “Organomodified” refers to organic pendant groups on the molecules that may include polyalkylene oxides such as polyethylene oxide, polyether groups, vinylic groups, and so forth.
In one embodiment, a mixture of at least one silane with at least one polysiloxane is advantageous in carrying out the invention. Suitable polysiloxanes for use in combination with at least one silane have the following general formula:
(R″ n SiO (4-n)/2 ) m
wherein
R″ is an organic or an inorganic group;
n is 0 to 3; and
m is equal to or greater than 2.
Examples of useful polysiloxanes in carrying out the present invention include, but are not limited to, polydimethylsiloxane (PDMS), vinyl phenylmethyl terminated dimethyl siloxanes, divinylmethyl terminated PDMS and the like, PDMS with polyether pendant groups including Silwet® PA-1 available from Crompton Corporation. PDMS such as Silwet® L-45, available from Crompton Corporation, is an example of a particularly useful polysiloxane.
The silanes preferable for use in combination with the polysiloxanes include those silanes described above such as 2-(3,4-epoxycyclohexaethyl triethoxy silane such as Silquest® Y-11870, and γ-glycidoxypropyltrimethoxy silane such as Silquest® A-187. The silane/polysiloxane mixture is useful from about 0.1 wt. % to about 5.0 wt. %, and preferably from about 1.0 wt. % to about 3.0 wt. %, based on a total weight of the silanized pigments. A preferred combination is about 0.5 wt. % to about 1.5 wt. % of the silane(s), and about 0.5 wt. % to about 1.5 wt. % of the polydimethylsiloxane based on a total weight of the silanized pigments. The ratio of silane(s) to polysiloxane may be from about 1:2 to about 2:1, with the preferred ratio being about 1:1.
In preparing the silanized pigment, the order of addition is not especially critical and the pigment may be treated with the silane using a number of different methods. For example, the silane can be either added neat or in a prehydrolyzed form to a dry pigmentary base, or it can be added into a slurry. The silane can be added during filtration, during drying, at a sizing operation such as a fluid energy mill, e.g. micronizer, or at a media mill. The silane may also be post blended after micronizing. One of skill in the art would be knowledgeable in treating the pigmentary base with the silane(s). For instance, media milling first involves reducing the viscosity of a high solids TiO 2 pigment slurry by adjusting the pH in the range of about 7.5 to about 11 with caustic or the like, or by contacting the slurry with a reducent, and then treating the slurry with an organosilicon reagent. The treating step is either preceded by and/or followed by media milling the high solids slurry to reduce the TiO 2 particle size. The slurry is then dried as a product thereby eliminating the post drying manipulation to control pigment properties such as particle size distribution.
The surface modification of pigments by may also be effectuated by adding amino organosilane to a pigment dispersion directly in a suitable solids mixing apparatus. Postblending processes may also be employed as well.
The description of the various preparation methods described herein is intended for guidance purposes only, and is in no way intended as a limitation on the scope of the present invention. One of skill in the art would realize that there are various methods and modifications of such methods which may be utilized to prepare the silanized pigments or fillers of the present invention. Such methods and modifications are seen to be within the scope of the present invention.
The polysiloxane addition may be made in conjunction with the silane, or added to the already silanized pigment. The silane addition and polysiloxane addition is described in greater detail below.
If water, either liquid or vapor (steam), is present as a component of the process stream, hydrolysis of the hydrolyzable groups of the silane will occur and the silane coating will bond to the TiO 2 base. Pre-hydrolyzing the silane is a preferred step in treating the TiO 2 pigment with the silane. Hydrolysis of silanes is described in greater detail in “ Organofunctional Silanes ” by Union Carbide (1991).
The treated pigment compositions of the present invention may further comprise a compatibilizer. The compatibilizer comprises at least one reactive group capable of reacting with the functional groups of the organosilicone compound. If, however, the polymeric material itself comprises such a functional group, a compatibilizer may not be utilized. For instance, if a modified polyolefin polymer with such a functional group is used, a compatibilizer may be superfluous. In the alternative, a compatibilizing compound may be added in addition to the polymeric material being utilized. In the case of a polymeric composition wherein the polymeric material is an unmodified polyolefin without any reactive groups, then a compatibilizer is additionally added to the composition.
Examples of useful compatibilizers include copolymers of ethylene or propylene with anhydride or acid groups capable of reacting with the functional groups of the organosilicon compound such as an epoxy group. The copolymers useful herein include ethylene maleic anhydride copolymers (EMAH), ethylene acrylic acid copolymers (EAA), ethylene methacrylic acid copolymers (EMAA), propylene maleic anhydride copolymers (PMAH), propylene acrylic acid copolymers (PAA), ethylene propylene copolymers with maleic anhydride or acid functional groups (EPMAH or EPAA), olefinic ionomer resins such as ethylene ionomers, and so forth. Ethylene maleic anhydride copolymers (EMAH) and ethylene-acrylic acid copolymers (EAA) are preferred.
Some specific examples of useful compatibilizers include ACX® ethylene-maleic anhydride copolymer resins from Allied Signal Corporation of Morristown, N.J., Primacor® ethylene-acrylic acid copolymer resins from The Dow Chemical Company of Midland, Mich., Surlyn® ionomer resins available from E.I. du Pont de Nemours and Company of Wilmington, Del., and Nucrel® ethylene methacrylic acid (EMAA) copolymers also available from E.I. du Pont de Nemours and Company. The compatibilizer is present in an amount from about 0.5 wt. % to about 20 wt. %, preferably from about 1.0 wt. % to about 10 wt. %, more preferably from about 1.0 wt. % to about 6.0 wt. %, and most preferably from about 3.0 wt. % to about 5.0 wt. % based on a total weight of the mixture which include the treated TiO 2 , polymer, compatibilizer, and any other components used in the mixture.
The silanized compounds of the present invention may be used in combination with any polymeric material with which such compounds are typically used. The silane acts, in a sense, as a dispersion promoter, by increasing the compatibility or dispersibility of the inorganic oxide or other particulate material within the plastic or resin system in which it is supplied.
The polymers useful herein are known to those of skill in the art. The general classes of polymers suitable for use herein are thermoplastic or thermosetting polymeric resinous materials, and include but are not limited to, the olefinic polymers including polyethylene and its copolymers and terpolymers, polybutylene and its copolymers and terpolymers, polypropylene and its copolymers and terpolymers; alphaolefins including linear or substantially linear interpolymers of ethylene and at least one α-olefin and atactic polyalphaolefins; rubbery block copolymers; polyamides; polyesters such as polyethyleneterephthalate and polybutyleneterephthalate; vinylic polymers; acrylics; epoxies; polycarbonates; and so forth; and mixtures thereof. Preferably, the polymers are selected from the group consisting of polyethylene, ethylene copolymers, polypropylene, propylene copolymers, and mixtures thereof.
Olefinic polymers, such as polyethylene, polypropylene and polybutylene, are from a broad class of polymers typically referred to as polymers of ethylenically unsaturated monomers, and the copolymers and terpolymers of such polymers with higher olefins such as alpha olefins containing 4 to 10 carbon atoms, or vinyl acetate, and the like.
Olefins, i.e. ethylene, are often copolymerized with vinyl monomers such as acrylates or vinyl esters of carboxylic acid compounds. Specific acrylate monomers include acrylic acid, methacrylic acid, acrylamide, methacrylamide, methyl acrylate, methyl methacrylate, methoxyethyl methacrylate, methoxyethyl acrylate, and so forth. Vinyl esters of carboxylic acids include vinyl acetate, vinyl butyrate and so forth. Commonly used polymers of this variety include, for instance, ethylene vinyl acetate, ethylene ethyl acrylate, ethylene n-butyl acrylate, and ethylene methylacrylate.
Other useful polymeric resins include vinylic compounds such as polyvinyl chloride; polyvinyl esters such as polyvinyl acetate; polystyrene, acrylic homopolymers, copolymers and terpolymers; phenolics; alkyds; amino resins; epoxy resins; polyamides; polyurethanes; phenoxy resins; polysulfones; polycarbonates; polyesters and chlorinated polyesters; polyethers; acetal resins; polyimides; polyoxyethylenes; and so forth.
Other useful polymers include various rubbers and/or elastomers including both natural and synthetic rubbers. Such polymers may be copolymerized, grafted, physically blending with various diene monomers, and so forth. Block copolymers are a commonly used elastomer and include polymers formed of styrene, butadiene, isoprene and so forth. More specifically, styrene-butadiene-styrene, styrene-isoprene-styrene, styrene-ethylene/butylene-styrene, styrene-ethylene/propylenestyrene, and so forth. Other elastomers include natural rubber, i.e. polyisoprene; polyisobutylene; butyl rubbers; and so forth.
Some polymers preferable for use in combination with the silanized compounds of the present invention include polyolefins such as polyethylene, polypropylene, polyvinyl chloride, polyamides, polyesters and copolymers and terpolymers thereof.
“High loaded” TiO 2 may depend on the type of polymer used and may be anywhere from about 40 wt. % TiO 2 , up to about 90 wt. % TiO 2 . For instance, in a polyolefin matrix, a high loaded TiO 2 would be about 50 wt. % or more of the TiO 2 pigment, based on a total weight of polyolefin matrix.
A wide variety of conventional additives may be optionally added to the polymeric compositions of the present invention as is necessary, desirable or conventional for the intended end use. Such additives include but are not limited to antioxidants, ultraviolet (UV) stabilizers, lubricants, thermal processing additives, and so forth. Such additives are known to those of skill in the art.
TiO 2 coated with organosilicon compounds can be incorporated with a polymer in a melted state to form the polymeric compositions of the present invention by any melt compounding technique known to those of skill in the art. Generally, TiO 2 and polymeric resin are added together, and are subsequently mixed in a blending apparatus that applies shear to the melted polymer. The polymeric resin is typically commercially available in a variety of forms including but not limited to powder, granules, pellets, cubes, and so forth.
In a typical mixing operation, pigment and polymer are first dry blended while the polymer is still in a solid, pre-melted state. This can be accomplished with simple processes such as by shaking in a bag or by tumbling in a closed container. More sophisticated methods include blending apparatuses having agitators or paddles. The pigment and the polymeric resin can be co-fed into mixers having an internal screw, i.e. an extruder device, which mixes the pigment and polymer prior to the polymer achieving a molten state.
Melt blending the components may be accomplished using any conventional equipment known to those of skill in the art including single-screw extruders, twin-screw extruders including the broad range twin screw extruders and corotating twin screw extruders, high shear mixers, blender type mixers, and so forth. Twin-screw extruders are commonly used. The melt blending can be accomplished during formation of an article such as during a melt extrusion process. Melt extrusion can also be combined with blow molding, for instance.
Exemplary mixers include co-rotating twin screw extruders manufactured by Werner & Pfleiderer in Ramsey, N.J., and by Leistritz Extruder Corporation in Somerville, N.J. Farrel Corporation in Ansonia, Conn. manufacturers the Farrel Continuous Mixers (FCM).
There are numerous ways of preparing the polymeric compositions of the present invention. A concentrate may first be prepared having a high concentration of TiO 2 , commonly referred to as a masterbatch, and then subsequently combining the concentrate with polymeric resin.
The highly loaded polymer concentrates are made as described above with the desirable weight % of pigment for the intended end use. For example, in polyolefin concentrates, about 50 wt. % to 85 wt. % concentrate may be used to opacify the composition. The TiO 2 concentrate is “let down” into the polymer. As used herein, “let down” refers to process of lowering the TiO 2 concentration in a resultant polymer. For example, in optical property evaluation, a concentrate having about 50 wt. % to about 87 wt. % TiO 2 may be let down to about 0.2 wt. % to about 30 wt. % by dry mixing polyolefin, extruding at a specific temperature, and casting it into a film. The pigment performance is then evaluated in an end use application.
The highly loaded silanized pigmentary TiO 2 exhibits outstanding processibility in polyolefinic matrices, and excellent lacing resistance. The torque and pressure can be utilized to determine the relative ease with which the compositions are processed through a mixer, e.g. an extruder, for instance. The lower the torque and pressure required to mix and move the composition through the equipment, the easier the processing. Furthermore, typically, the higher the loading of pigment or filler, i.e. TiO 2 , in a polymer concentrate, the slower the processing rates.
The compositions of the present invention require lower torque and pressure for processing, particularly through an extruder, than do those polymeric compositions compounded with untreated titanium dioxide, and faster processing rates can also be obtained. Another advantage of the polymeric films made using the pigmented compositions of the present invention, particularly those made with the silanized TiO 2 of the present invention, is increased lacing resistance. Other advantages include increased bulk density, lower viscosity, excellent dispersion, excellent moisture resistance, and excellent optical properties such as high whiteness and gloss.
The polymeric materials containing the treated pigments of the present invention are useful in a variety of applications. The polymeric compositions of the present invention may be employed, for example, for molding (including extrusion, injection, calendering, casting, compression, lamination, and/or transfer molding), coating (including lacquers, film bonding coatings and painting), inks, dyes, tints, impregnations, adhesives, caulks, sealants, rubber goods, and cellular products. Thus, the choice and use of the polymeric compositions with the treated particles of this invention is essentially limitless.
One of ordinary skill in the art would understand that there are a vast number of modifications which could be made without changing the scope of the invention, those modifications and embodiments thereof are contemplated to be within the scope of the present invention.
The following non-limiting examples are further illustrative of the present invention, and are in no way intended to limit the scope of the present invention.
EXAMPLES
Test Methods
1. Viscosity (Pascal/second) and Melt Flow Index (g/10 Minutes)
The viscosity and melt flow index were measured at 190° C. using a Tinius Olsen Extrusion Plastometer available from Tinius Olsen Corporation in Willow Grove, Pa.
2. Yellow Index and Whiteness
The yellowness index and whiteness were measured using the films and plaques as prepared above using a Colorgard System™ 1000 colorimeter manufactured by Pacific Scientific Corporation in Silver Spring, Md. Film thickness was about 4 mils.
3. Gloss
The gloss of the film and plaque samples was measured with a GL-4525 glossmeter manufactured by Paul N. Guard Co. in Pompano Beach, Fla. Film thickness was about 4 mils.
4. Hue and Chroma
The hue and chroma of the film and plaque samples were measured using a Minolta® CR 231 chromameter available from Minolta Corporation in Osaka, Japan. The films tested had a thickness of about 4 mils.
5. Dispersion
The dispersion of the pigment was tested using a light box. Film thickness was approximately 1 mil. The dispersion is rated according to the distribution and uniformity using a rating of excellent, good, fair and poor.
The following examples were prepared using a masterbatch concentrate prepared in the following manner. The masterbatch concentrate contained 80 wt. % TiO 2 in low density polyethylene (LDPE). The TiO 2 powder was treated with silane or a silane/siloxane combination, and mixed with low density Microthene® GMN 711-20 LDPE available from Equistar Corporation in Houston, Tex., having a melt flow index (MFI) of 22, and a compatibilizer which was an ethylene-maleic anhydride copolymer, ACX® 575 available from Allied Signal Corporation in Morristown, N.J., or Primacor® 2410, an ethylene-acrylic acid copolymer available from The Dow Chemical Company, in Midland, Mich. The composition was mixed in a Henschel dry mixer manufactured by Prodex Corporation in Fords, N.J. The dry mix was then fed into a twin screw extruder (ZSK 30 by Werner & Pfleiderer of Ramsey, N.J.) for a melt compounding. The twin screw extruder was equipped with recording equipment for recording temperature, pressure, rotating speed, torque and power consumption. The extruded rods were fed into a water bath, air knife and pelletizer. The 80 wt. % high loaded TiO 2 /LDPE pellets were dried at 140° F. (60° C.) for about 8 hours and then made into films using a Brabender PL-V302 single extruder with a 6″ wide slot die. The films were tested for dispersion of TiO 2 in LDPE using a light box.
The masterbatch was then let down to 8%. The balance of LDPE (Petrothene® NA206, MFI™ 13 available from Equistar Corporation), antioxidant (Irganox® B-215 and 1010, from Ciba Specialty Chemicals in Tarrytown, N.Y.) and ultraviolet stabilizer (Tinuvin® 783FP, also from Ciba Specialty Chemicals) were added into the Masterbatch pellets with a bag dry mixing. The dry mix was fed into a 2″ single screw extruder (Midland Ross Hartic) for a melt compounding. The extruded strands went through a water bath and pelletizer.
The let down pellets were made into film samples using a Brabender model PL-V302 single extruder with a 6″ wide slot die. The dispersion of TiO 3 in LDPE was checked for these film samples with a light box. The film samples were also used for the measurement of optical performance (whiteness, yellow index, gloss, hue and chroma).
The let down pellets were also made into plaques by compression molding. Film thicknesses were approximately 4 mils.
Example 1
RCL-9™ pigmentary rutile TiO 2 supplied by Millenium Inorganic Chemicals in Baltimore, Md. (2500 g) was added to a Patterson-Kelly Twin shell V-Blender and sprayed with a solution of 25 g of A-187 γ-glycidoxy propyltrimethoxysilane available from Crompton Corporation. The solution was about 20 wt. % silane in 90/10 methanol/water. The silanized TiO 2 (2400 g) was then dried in an oven at 140° F. (60° C.) for 8 hours.
The silanized TiO 2 was then compounded with 450 g of Microthene® GMN 711-20 LDPE having a MFI of 22 available from Equistar, and 150 g of ACX® 575 ethylene-maleic anhydride copolymer compatibilizer available from Allied Signal. The compounding was accomplished using a twin screw extruder model ZSK 30 by Werner & Pfleiderer. The weight ratio of treated TiO 2 to LDPE to compatibilizer was 80:15:5. The composition was formed into pellets and film samples were prepared using a Brabender model PL V302 single screw extruder with a 6″ wide slot die.
Example 2
RCL-9 pigmentary rutile TiO 2 was treated with 1% γ-glycidoxy propyltrimethoxysilane and 1% L-45 polydimethylsiloxane (PDMS) available from Crompton Corporation. The TiO 2 was first treated with the γ-glycidoxy propyltrimethoxysilane. The PDMS (24 g) was then mixed with the silanized TiO 2 (2400 g), LDPE (450 g) and compatibilizer (150 g) in a Henschel mixer for about one minute at 2200 RPM as in Example 1. The dry mix was then compounded through a twin screw extruder as in Example 1.
Example 3
Example 1 was repeated using 2-(3,4-epoxycyclohexal)ethyltriethoxysilane, Y-11870, available from Crompton Corporation, instead of the γ-glycidoxypropyltrimethoxysilane.
Example 4
Example 2 was repeated using Silquest® Y-11870 2-(3,4-epoxycyclohexal)ethyltriethoxysilane, available from Crompton Corporation, instead of the γ-glycidoxypropyltrimethoxysilane.
Comparative Example A
Untreated RCL-9 TiO 2 was dry mixed with Microthene GMN-711-20 LDPE (MFI 22) using a plastic bag. The mix was then fed into a twin screw extruder for compounding.
The results of the tests using Examples 1-4 and Comparative A are summarized in Table I below.
TABLE I
Observations
Torque
Pressure
during
Example
(ft-lb)
(psi)
Dispersion
extrusion
1
1640
<25
good
low feed rate
but acceptable
2
1650
<25
good
runs well,
smooth surface
3
1780
<25
good
low feed rate
but acceptable
4
1750
20
excellent
runs well,
smooth surface
Comparative
2600
400
a film could
Brittle, rough
A
not be made
Surface, very
difficult to
process
The data found in Table I demonstrates the processing advantages of using TiO 2 that has been treated with an organosilicone compound (Examples 1-4) as compared to an untreated TiO 2 (Comparative A) as opposed to using an untreated TiO 2 pigment (Comparative A) in a high loaded 80 wt. % TiO 2 /polyethylene masterbatch. The torque and pressure can be used as a means of determining the relative ease with which each composition is processed through the extruder. As can be seen from the data, the comparative example with the untreated titanium dioxide requires both higher torque and higher pressure for processing the composition through the extruder.
Using the untreated TiO 2 lead to compounding difficulty in making a high loaded 80 wt. % TiO 2 masterbatch with LDPE. Films could not be made using the composition with the untreated TiO 2 . Compounding was accomplished at a 30 wt. % level of TiO2.
The 30 wt. % loaded compositions were selected due to the incompatibility between untreated TiO 2 and LDPE. This incompatability resulted in difficulty in producing a masterbatch of LDPE filled with untreated TiO 2 . Furthermore, films of LDPE highly loaded with untreated TiO 2 could not be successfully made. The untreated TiO 2 could be used to successfully produce a 30 wt. % loaded LDPE masterbatch, and films could be made thereof. Consequently, compounding experiments were conducted at a 30 wt. % loading of both treated and untreated TiO 2 to ensure accurate comparative results.
Comparative Example B
Untreated RCL-9 TiO 2 was dry mixed with Microthene® GMN 711-20 LDPE (MFI 22) at a weight ratio of 30:70 using a plastic bag. The mixture was then fed into a twin screw extruder and compounded as in Comparative Example A. The composition was formed into pellets dried. Film samples were prepared using a Brabender PL-V302 single extruder with a 6″ wide slot die.
Example 5
Comparative example B was repeated except that the TiO 2 was treated with 1% γ-glycidoxy propyltrimethoxysilane (A-187) available from Crompton Corporation, and a compatibilizer (ACX® 575 ethylene-maleic anhydride copolymer available from Allied Signal) was added. The weight ratio of treated TiO 2 to LDPE to compatibilizer was 30:67:3.
Example 6
Example 5 was repeated using TiO 2 treated with 1% γ-glycidoxy propyltrimethoxysilane (A-187) and 1% PA-1 organomodified polydimethylsiloxane available from Crompton Corporation The weight ratio of treated TiO 2 to LDPE to compatibilizer was 30:67:3.
Example 7
Comparative example B was repeated using TiO 2 treated with 1% 2-(3,4-epoxycyclohexyl)ethyltriethoxysilane (Y-11870), and a compatibilizer (ACX 575, ethylene-maleic anhydride copolymer) was added. The weight ratio of treated TiO 2 to LDPE to compatibilizer was 30:67:3.
Example 8
Example 7 was repeated using TiO 2 treated with 1% 2-(3,4-epoxycyclohexal)ethyltriethoxysilane (Y-11870) and 1% PA-1 organomodified polydimethylsiloxane. The weight ratio of treated TiO 2 to LDPE to compatibilizer was 30:67:3.
The viscosity and melt flow rate of the pellets were measured using an extrusion plastometer manufactured by Tinius Olsen. The whiteness and yellowness index of the film samples were measured using a Colorgard® System 05 colormeter manufactured by Pacific Scientific. The results are summarized in Table 2 below.
TABLE II
Viscosity
Flow Rate
Whiteness
Yellowness
Example
(Pa/sec)
g/10 minutes
ASTM D 1925
ASTM D 1925
Comparative
841.5
12.6
71
7.32
B
5
869.1
12.3
90
2.56
6
746.2
13.1
89
2.52
7
776.6
13.0
86
3.36
8
696.3
14.8
86
3.0
The data found in Table II demonstrates the improved processing parameters, lower viscosity, higher whiteness and lower yellowness achieved using the organosilicone treated TiO 2 pigments (Examples 5-8) versus using an untreated TiO 2 pigment (Comparative B) in a 30 wt. % TiO 2 /polyethylene masterbatch. The viscosity and melt flow rate were measured using the pellets, and the whiteness and yellowness index were measured using films having a thickness of approximately 4 μm.
Comparative Example C
Comparative Example B was repeated using untreated ground CaCO 3 . The weight ratio of untreated CaCO 3 and Microthene® GMN 711-20 LDPE (MFI 22) was 30:70.
Example 9
Example 6 was repeated using ground CaCO 3 treated with 1% γ-glycidoxy propyltrimethoxysilane (A-187) and 1% L-45 polydimethylsiloxane available from Crompton Corporation at Greenwich, Conn. The weight ratio of treated CaCO 3 to LDPE to compatibilizer (ACX 575) was 30:67:3.
TABLE III
Whiteness
Yellowness
Example
ASTM D 1925
ASTM D 1925
Comparative C
22
20.89
Example 9
40
14.52
The data found in Table III demonstrates the higher whiteness and lower yellowness achieved using the organosilicone treated CaCO 3 (extended white pigment, Example 9) versus using an untreated CaCO 3 (Comparative Example C) in a 30 wt. % CaCO 3 /polyethylene masterbatch.
Example 10
By weight, 20% of an epoxysilane (Silquest® A-187) treated TiO 2 was compounded with 2% EMAH and balance polyethylene. Material was extruded on a Brabender PL-V302 single screw extruder through a slit film die at 620° F. Evaluation of the film on a light box revealed superior integrity with no thin spots or pin-holes. Rating of material equaled 10. Lacing resistance was comparable to the industry standard Ti-Pure® R-104, available from E.I. du Pont de Nemours and Company.
Comparative Example D
By weight, 20% of an untreated TiO 2 pigment RCL-9 available from Millenium Chemicals, Inc. in Baltimore, Md., was compounded into balance polyethylene. Material was extruded on a Brabender PL-V302 single screw extruder through a slit film die at 620° F. The film exhibited thin spots and pin-holes under a light box. The material was rated as a 6.
Lacing occurs as a function of pigment volatility at specific wt-% pigment loadings and processing temperature. For polyethylene films pigmented with titanium dioxide, 20% wt. % Ti 2 in the film processed at temperature of 620° F. or greater will readily exhibit lacing of the film. Typically, materials are rated 10 if they do not lace, and below 10 if they begin to lace. Example 10 and comparative example D were compared above for lacing.
Having thus described and exemplified the invention with a certain degree of particularity, it should be appreciated that the following claims are not to be so limited but are to be afforded a scope commensurate with the wording of each element of the claim and equivalents thereof. | The present invention is directed to a composition comprising a white pigment or extended white pigment surface treated with a silane having at least one functional group capable of reacting with acids and anhydrides, at least one polymeric material and a compatibilizer. Once treated, the pigment has improved processability and dispersibility in polymeric materials. Silanizing the pigment also enhances the brightness (increase whiteness and reduce yellowness) of the pigment. | 2 |
BACKGROUND OF INVENTION
The present invention relates to a process for improving the adhesion of organic coatings such as paint to metal surfaces, particularly aluminum and aluminum alloys. The process cleans and prepares the metal surfaces such that subsequently applied organic coatings to the metal surfaces, such as paint, adhere to the metal surface in a superior fashion.
SUMMARY OF THE INVENTION
The proposed invention teaches the treatment of metal surfaces, particularly aluminum or aluminum alloy surfaces, with a process comprising:
1. Contacting the metal surface with an adhesion promoting solution comprising:
a) a glycol ether;
b) an oxidizing acid;
c) a nitro sulfonic acid; and optionally, 1,2 bis(beta-chloroethoxy)ethane;
2. subsequently contacting the metal surface with a chromating composition in order to create a chromate conversion coating on the metal surface; and
3. subsequently applying an organic coating to the metal surface.
DETAILED DESCRIPTION OF THE INVENTION
The inventor herein that discovered that treatment of metal surfaces, particularly surfaces of aluminum and aluminum alloys, with a specific process greatly improves the adhesion of subsequently applied organic coatings to such metal surfaces. In order to accomplish this, the inventor proposes the following process:
1. contacting the metal surface with an adhesion promoting solution comprising:
a) a glycol ether;
b) an oxidizing acid; and
c) a nitro sulfonic acid; and
d) optionally, 1,2 bis(beta-chloroethoxy)ethane;
2. subsequently contacting the metal surface with a chromating composition in order to create a chromate conversion coating on the metal surface; and
3. subsequently applying an organic coating to the metal surface.
Many metals may be treated with the process of the invention but the inventor has found the process to be particularly useful in preparing aluminum and aluminum alloys for painting.
The adhesion promoting composition of the proposed process optionally contains 1,2-bis(beta-chloroethoxy)ethane at a concentration of from 0.1 to 10 percent by weight. Preferably the concentration of 1,2-bis(beta-chloroethoxy)ethane is from 0.5 to 2.0 percent by weight. 1,2-bis(beta-chloroethoxy)ethane is only sparingly soluble in water, however a glycol ether, or equivalent substance or solvent, may be utilized to increase the solubility of 1,2-bis(beta-chloroethoxy)ethane in the adhesion promoting composition.
The adhesion promoting composition may contain a glycol ether. Preferably the glycol ether will be a lower alkyl ether of ethylene glycol, propylene glycol, polyethylene glycol and polyproplene glycol. Some examples of appropriate glycol ethers include ethylene glycol mono butyl ether, ethylene glycol monomethyl ether, propylene glycol monomethyl ether, diethylene glycol monomethyl ether, diethylene glycol mono-n-butyl ether, diethylene glycol monohexyl ether, triethylene glycol monomethyl ether, other similar glycol ethers and mixtures of any of the foregoing. The concentration of the glycol ether may range from 2 to 40 percent by weight but is preferably from 10 to 20 percent by weight. Ethylene glycol mono-butyl ether, commonly marketed under the tradename Butyl Cellosolve, is a preferred glycol ether.
The adhesion promoting composition will contain an oxidizing acid. As indicated, the composition will also comprise a nitro sulfonic acid. The nitro sulfonic acid may also act as the necessary oxidizing acid.
The oxidizing acid is preferably nitric acid and/or a nitro sulfonic acid but most preferably both nitric acid and a nitro sulfonic acid are utilized in combination. The concentration of the oxidizing acid may range from 0.1 to 20 percent by weight, but is preferably from 0.1 to 10 percent by weight. If nitric acid is utilized in combination with a nitro sulfonic acid then the concentration of nitric acid (69%) is preferably from 0.1 to 2 percent by weight and the concentration of the nitrosulfonic acid is from 2 to 8 percent by weight.
The adhesion promoting composition contains a nitro sulfonic acid. Examples of useful nitro sulfonic acid include p-nitro benzene sulfonic acid, M-nitrobenzene sulfonic acid, 2-chloro-5 nitrobenzene sulfonic acid, 2,4 dinitrobenzene sulfonic acid, p-nitrotoluene sulfonic acid, 3,5 dinitro-p-toluene sulfonic acid and the like. The concentration of the nitrosulfonic acid may range from 2 to 10 percent by weight but is preferably from 3 to 8 percent by weight.
The adhesion promoting composition may also contain surfactants or water soluble polymers. The inventors have found that the addition of non-ionic surfactants and water soluble polymers are advantageous to the performance of the adhesion promoting composition. In particular homopolymers or copolymers of ethylene oxide and/or propylene oxide have been found to be useful. In addition non-ionic surfactants have also proven to be useful. The concentration of surfactant and water soluble polymers in the adhesion promoting composition may range from 0.5 to 3 percent by weight but is preferably from 1 to 2 percent by weight.
Finally, it may be advantageous to incorporate thickeners into the formulation, if the adhesion promoting composition is to be applied to vertical surfaces.
The chromating composition to be used in the process can be any composition capable of effectively creating a chromate conversion coating on the surface of the metal being treated. In this regard the teachings of U.S. Pat. No. 2,796,370 are herein incorporated by reference in their entirety. The inventors have found Iridite 14-2 a chromating solution available from MacDermid, Incorporated of 245 Freight Street, Waterbury, Conn. to be particularly useful in this regard.
The adhesion promoting composition and the chromating composition may be applied to the metal surface by either immersion, spray or equivalent method. The compositions should preferably remain in contact with the metal surface for a minimum of several minutes.
The inventors have found an unexpected synergism to occur when utilizing both the adhesion promoting composition and the chromating composition. The synergism is particularly unexpected since both the adhesion promoting composition and the chromating composition are reactive coatings (ie. react with the surface treated to create a modified surface). Conventional wisdom would dictate that it would not be advisable to employ two reactive coatings, one on top of the other since the first should either inhibit the formation of the second or the second will overcome and replace the first. In this case the unexpected synergism between the two coatings indicates that the coatings unexpectedly co-exist on the treated surface in some way.
The following example illustrates the foregoing invention but should not be taken as limiting in any way.
EXAMPLE I
An air-foil shaped piece of aluminum metal was processed through the following process:
Time
1. alkaline soak cleaner to
7 minutes
remove any oily residues
2. clean water rinse
2 minutes
3. adhesion promoting composition
15 minutes
4. clean water rinse
2 minutes
5. MacDermid Iridite 14-2 chromate
5 minutes
6. clean water rinse
2 minutes
7. dry
The adhesion promoting composition contained the following:
Concentration
Substance
(weight percent)
ethylene glycol monobutyl ether
16
p-nitro toluene sulfonic acid
6
1,2 bis (beta-chloroethoxy) ethane
1
nitric acid (42 BE)
0.4
ethylene oxide homopolymer (MW = 7700)
0.5
ethoxylated non-ionic surfactant
1
water
75.1
An epoxy primer and polyester top coat was applied to the processed aluminum specimen and allowed to cure. The adhesion of the paint was checked using the rain erosion method, a paint adhesion test method well known in the aerospace industry. In the rain erosion test water droplets impinge at high speed upon the line of demarcation between a painted and unpainted area on the specimen. The test is intended to simulate the water-blast stripping or eroding effect on the painted surface of an aircraft moving at high speed. A reasonable pass-fail criterion for this test requires that no greater than ¼ inch erosion occur behind the leading edge of the paint line. The specimen which was prepared in accordance with this example yielded a passing adhesion valve of not more than ⅛ inch erosion.
EXAMPLE II
Example I was repeated except that only steps 1,2 and 7 of the process were employed (ie. the aluminum was cleaned, rinsed and dried only). The same paint system cited in Example I was used along with the same testing scheme. The adhesion was found to be lacking in that the rain erosion test produced a maximum allowable erosion of ¼ inch or more. | A process is described for increasing the adhesion of organic coatings to metal surfaces, particularly aluminum and aluminum alloys. The process involves the utilization of an adhesion promoting composition in conjunction with a chromating composition in treating the metal surface prior to application of the organic coating. The adhesion promoting composition comprises (i) 1,2-bis(beta-chloroethoxy)ethane, (ii) a glycol ether, (iii) an oxidizing acid and (iv) a nitro sulfonic acid. | 1 |
This application is a continuation-in-part application of U.S. patent application Ser. No. 872,121 filed June 9, 1986, now U.S. Pat. No. 4,677,883 issued on July 7, 1987.
BACKGROUND OF THE INVENTION
This invention relates to a cork screw construction and particularly to one having a rotary handle incorporating a stem and a penetrating screw, and a housing pedestal to be seated against a spout of a bottle, wherein an improved engaging dog member is mounted in the pedestal and a sliding sleeve is provided around the stem to cause the dog member to engage with and disengage from a helical groove of the stem upon rotation of the handle.
The basic application of this application discloses a cork screw of the above described type but with two fulcrumed dog members at two opposite outer sides of the pedestal. In operation, the dog members are first manipulated to be in a position disengaging from the helically grooved stem before the handle is rotated to cause the screw to penetrate the cork. The helical groove of the stem and the screw are arranged in such a manner that they are not in the same screw direction, i.e. if the screw is right-handed, the helical groove of the stem is left-handed. During the handle rotation, the dog members return to their normal position engaging with the stem, causing the stem to turn upward and pulling the screw upward. The above described cork screw is still inconvenient since the dog members must be depressed by hand to a position disengaging from the stem before the rotation of the handle.
SUMMARY OF THE INVENTION
An object of the invention is to provide a cork screw which can be manipulated in a manner more convenient than conventional cork screws.
Another object of the invention is to provide a cork screw with a sanitary holding member that can prevent a pulled out cork from being polluted by a hand when the cork is reused.
The present invention provides a cork screw which comprises, a rotary handle, a stem connected to the handle and having a helical groove extending on the periphery of the stem, a penetrating screw fixed to the bottom of the stem, a hollow pedestal having an upper surrounding wall portion receiving the stem and a lower portion having a cross-section greater than the upper wall portion and adapted to be seated against a spout of a bottle, the upper wall portion having a hole therein, a sliding sleeve surrounding the stem and fitted in the upper wall portion in an axially slideable position, the sleeve having an opening aligned radially with the hole, a dog member pivotally mounted in the hole and having an engaging end extending into the opening, the engaging end extending to the interior of the sleeve through the opening and engaging the stem when the opening is at a first level relative to the hole, and a spring means for biasing the sleeve to move the opening to a second level higher than the first level so as to retract the engaging end.
In one aspect of the invention, the cork screw further comprises a holding member which can be inserted in and separated from the pedestal, the holding member including a substantially cylindrical hollow base member and a plurality of separate upstanding clamping members which are of one piece with and extending from the base member at annularly spaced apart positions and each of which has an inwardly projecting clamping face, and a tongue-and-groove engagement means to interengage the holding member and the pedestal.
The present exemplary preferred embodiment will be described in detail with reference to the following drawings, in which:
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a sectional view of a first embodiment of a cork screw according to the present invention;
FIG. 2 is a fragmentary elevation view of the cork screw of FIG. 1;
FIG. 3 is a sectional view showing that the penetrating screw of the cork screw of FIG. 1 penetrates into a cork;
FIG. 4 is a perspective view of a second embodiment of the invention;
FIG. 5 shows a holding member to be incorporated in the cork screw of FIG. 1;
FIG. 6 is a sectional view showing an application of the holding member; and
FIG. 7 is a sectional view showing another application of the holding member.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to FIGS. 1, 2, and 3, a preferred embodiment of a cork screw according to the present invention is shown, having a rotary handle 10 connected to a stem 20 having a helical groove 21 extending on its periphery, and a penetrating screw 30 connected to the stem 20. Around the stem 20 and the cork screw 30 is a one-piece pedestal 40 which includes an upper cylindrical surrounding wall portion having a cylindrical inner periphery 41 with a first annularly stepped portion 42 and a second annularly stepped portion 43. Two axial column 45 extend downwardly from two diametrically opposite positions of the pedestal 40, carrying a substantially cylindrical portion 46 which has two inwardly projecting flanges 46a to abut against a spout 63 of a bottle. A hole 44 is disposed in the top portion of one of the columns 45 and in the upper wall portion of the pedestal.
In the hole 44 is mounted pivotally a dog member 48 which has an engaging end 49. A sleeve 50 is fitted slideably in the upper portion of the pedestal and sleeved around the stem 20. On the inner periphery 41 of the pedestal 40 is two diametrically opposite axial projections 41a to engage with two axial grooves 51 of the sleeve 50, whereby the sleeve 50 slides only in an axial direction relative to the pedestal 40. The sleeve 50 has a neck portion 52 and an annular shoulder 52 which combine with the annularly stepped portions 42 and 43 to confine a space for receiving a spring 54. The spring 54 normally biases the sleeve 50 upward. The sleeve 50 further has an opening 55 aligned radially with the hole 44 of the pedestal 40, and the engaging end 49 of the dog member 48 extend into the opening 55, thereby preventing the sleeve from releasing out of the pedestal.
In one of the columns 45 of the pedestal 40 is pivoted a knife 58 which can be pulled out of the column 45 for use. The knife 58 can be used to cut a plastic sealing sheet (not shown) that wraps around a spout of a bottle by placing the spout against the cutting edge of the knife 58 and the column 45 and then rotating the bottle.
Normally, the engaging end 49 of the dog member 48 does not extend into the interior of the sleeve 50 due to the action of the spring 54 to move the sleeve 50 upward. When one turns the handle 10 to cause the penetrating screw 30 to penetrate into a cork 66 of a bottle, the handle moves towards and depressed the sleeve 50 so that the sleeve slides downward against the action of the spring 54 until the engaging end 49 of the dog member 48 extends into the interior of the sleeve 50 and engages with the stem 20. As soon as the engaging end 49 engages the stem 20, the continuous turning of the handle 10 in the same direction causes the stem 20 to rotate and move upward relative to the pedestal 40, thereby lifting the cork from the bottle. The engaging end 49 of the dog member 48 does not disengage from the helical groove 21 of the stem 20 until the cork is pulled entirely out of the bottle. This is because the engaging end 49 is prevented from moving upward by its engagement with the ridge surface 211 confining the helical groove 21 due to the stem 20 which is subjected to a downward force caused by the cork still held in the bottle, as better shown in FIG. 3. When the cork is pulled entirely out of the bottle, the downward force disappears and the engaging end 49 is moved upward by the action of the spring 54 and disengages from the helical groove 21. The stem 20 is restricted from moving out of the pedestal by its flange 22 which can engage with the inner surface of the pedestal. With the sleeve 50, the cork screw can pull out a cork just by simply rotating the handle 10 in one direction without a need to operate manually the dog member.
FIG. 4 shows a second embodiment of the invention, wherein elements similar to that of the first embodiment are designated by similar reference numerals. This embodiment is substantially similar to the first embodiment except for that two semi-cylindrical bottom members 46' are provided to replace the cylindrical member 46 which is connected to the two columns 45. On the inner surfaces of the semi-cylindrical bottom members are provided respectively two inwardly projecting clamping members 46a' each with a toothed clamping surface 46b'. When the two semi-cylindrical bottom members 46' are squeezed, the inwardly projecting clamping members 46a' will clamp the cork which is pulled out of the bottle. While clamping the cork, the penetrating screw 30 can be released from the cork by rotating the handle in the direction opposite to that which causes the penetrating screw 30 to penetrate into the cork.
FIGS. 5 through 7 show a third embodiment of the present invention wherein elements similar to that of the first embodiment are designated by similar reference numerals. In comparison with the first embodiment, this embodiment additionally includes a holding member 60 detachably inserted in the pedestal 40'. The holding member 60 includes a substantially cylindrical hollow base portion 61 having an inner shoulder formation 62 to abut against the spout of a bottle, and an upper clamping portion extending upwardly from the top of the cylindrical base portion 61. The upper clamping portion has a plurality of upstanding clamping members 64 and upstanding blocks 65 oriented annularly and slightly spaced apart from each other. The clamping members 64 are longer than the upstanding blocks 65 and are provided with clamping projections 64a with toothed clamping surfaces 64b. The clamping members 64 are disposed alternatingly with respect to the upstanding blocks 65. On the outer sides of the upstanding blocks 65 are provided axially extending tongues 67. When the holding member 60 is press fitted in the lower portion of the pedestal 40', the tongues 67 are engaged in axial grooves 68 provided in the inner side of the pedestal 40', preventing the member 60 from rotation relative to the pedestal 40'.
The holding member 60 can be used to hold the stem 20 in the pedestal 40' when the device is not in use, and to clamp a cork and separate it from the penetrating screw 30 after the cork is pulled out of the bottle. When the member 60 is inserted into the pedestal as shown in FIG. 6, the clamping members 64 are bent inwardly by inwardly projecting members A of the pedestal 40' and thus clamp the flange 22 of the stem 20, thereby holding the stem 20 against an outward movement.
After the penetrating screw 30 pulls out a cork, the cork can be removed from the penetrating screw 30 by inserting the member 60 into the pedestal 40' as shown in FIG. 7. The clamping members 64 clamp the cork and prevent it from moving together with the penetrating screw 30 when the penetrating screw is moved upward by turning the handle 10 or stem 20 is turned in a direction opposite to that which causes the penetrating screw to move downward. If the pulled out cork is to be re-inserted into the spout of a bottle one may seat the base member 61 of the holding member 60 against the spout and depress the top side of the cork to cause the cork to enter the spout. The holding member provides an advantage in that a pulled out cork will not be polluted by hand when it is either pulled out of or put into the spout.
With the invention thus explained, it is apparent that various modifications and variations can be made without departing from the scope of the invention. It is therefore intended that the invention be limited as indicated in the appended claims. | A cork screw which comprises a pedestal and a rotary handle incorporating a stem and a penetrating screw wherein the pedestal incorporates a dog member to engage with a helical groove of the stem and a spring biased sleeve around the stem to cause the dog member to engage with the helical groove when the handle is turned in a certain direction and disengage therefrom when a cork is pulled entirely out of a bottle. A holding member is incorporated in the pedestal to hold a cork after it has been pulled out of a bottle. | 1 |
BACKGROUND
[0001] 1. Field of the Invention
[0002] The present invention relates generally to improved energy efficient air and process gas adsorption/desorption vessel assemblies with removable radial-flow adsorption bed cartridge subassemblies, particularly applied to VSA gas separation vessels producing a high purity oxygen gas product or other purified process product.
[0003] Within the process gas industry, and in particular within the air separation market, the continuing increasing costs of electric power makes the energy efficiency of gas separation systems of ever increasing importance. The common art methods of separating a desired molecular gas from a mixture of process gases, or the separation of nitrogen from air to provide a highly predominant oxygen gaseous product stream, commonly includes the utilization of (a) power-intensive multi-stage membrane separation system, or refrigerated or cryogenic generated liquid extraction systems; (b) pressure swing adsorption (PSA) systems for producing moderate pressure supplies of predominant oxygen gas; and (c) vacuum pressure swing adsorption (VPSA) units, or also interchangeably referred to as vacuum swing adsorption swing units (VSA) units. VSA units generally require the least of all system power consumptions per ton of product gas of less than 100% purity.
[0004] Controlled temperature swing adsorption (TSA) applied within PSA or VSA cycles can be employed when a selected preferred adsorbent exhibits superior gas adsorption/desorption performance within specific ranges of operating gas temperature. Application of TSA is typically employed in the example separation of hydrogen from within a catalytic steam-reforming process reaction system that produces a typical process gas stream mixture of hydrogen, carbon monoxide and carbon dioxide, and the separation of one or more hydrocarbon gases from a petrochemical or petroleum refining process supplied feed gas mixture of hydrocarbon gases. In the case of adsorbed hydrogen being the preferred gas product, the hydrogen gas product is discharged from the gas separation vessel during the desorption cycle portion of the gas separation process.
[0005] There is therefore a need for a gas separation vessel apparatus assembly that can operate with, but not limited to, low pressure gas feedstock adsorption/desorption systems with extraordinary low system differential pressures that further contributes to achieving the lowest VSA gas separation systems energy consumptions (or Best Available Technology energy performance). A need also exists for an assembly that addresses other important long-term operational requirement needs for future rapid adsorbent replacement for upgraded performance capabilities.
[0006] Gas separation feedstock gases can comprise low positive pressure ‘vapor recovery’ or process ‘off-gases’ developed within facility petrochemical process or petroleum refining operations. They can also comprise feedstock air (or conditioned air at atmospheric or slight sub-atmospheric pressure) to produce a predominant rich oxygen product gas of lesser flow during a gas separation vessel's adsorption sequence of operation, and a predominant nitrogen gas waste gas of greater flow during a gas separation vessel desorption sequence of operation.
[0007] In the case of petroleum refining operations wherein at least two hydrocarbon gases having different adsorption characteristics are present, the more strongly adsorbable gas can be an impurity which is removed from the less strongly adsorbable gas which is taken off as a product gas; or, the more strongly adsorbable gas can be the desired product gas that is separated from the less strongly adsorbable gas. A petroleum refining process stream mixture of propylene and propane is such an example. Propylene is the more valued product and the more strongly adsorbable gas which can be separated from the less strongly adsorbable propane gas of lesser value.
[0008] In the case with large industrial petrochemical and petroleum refining facilities, process gas streams may be varied in composition within a relative short time period, compared to other industries continuous process streams that may remain unchanged for a number of years. From a facility lost revenue and operating cost standpoint, it is important to be able to minimize labor, material expense, and the time required to remove and replace the old adsorbents with new optimum performance adsorption materials as required to adapt existing gas separation or adsorption-desorption vessels to these new variances in process gas composition streams. Especially in low pressure gas streams, unnecessarily high adsorbent bed gas velocities and accompanying separation vessel pressure drops can result in the loss of adsorbent performance from bed fluidization and significant increased electric power costs for gas compression. To achieve the combined needs of providing operating high energy efficient gas separation vessels that are economically adaptable to rapid upgrades or changes in adsorbent bed material, the present invention includes an improved gas separation vessel assembly and internal subassembly device Adapted to satisfy these needs.
[0009] 2. Description of Related Art
[0010] A sample review of known U.S. patents having variations of typical current art gas separation vessels within PSA and VSA systems includes the following: U.S. Pat. No. 5,759,242 discloses the design of a vertical adsorber vessel having an internal means to direct gas flows radially through the molecular sieve adsorbent material contained within the welded-closed vertical adsorber vessel. The ‘Background of the Art’ within U.S. Pat. No. 5,759,242 extensively describes the numerous operating shortcomings of conventional VSA vertical adsorber vessels having axial gas flows through the vertical beds of molecular sieve adsorbents.
[0011] U.S. Pat. No. 5,964,259 discloses an apparatus design and method of loading multiple molecular sieve adsorbents into the interior of a welded-closed vertical adsorber vessel therein designed to contain vertical radial-flow adsorbent beds as described in U.S. Pat. No. 5,759,242.
[0012] U.S. Pat. No. 6,086,659 addresses adsorption vessel design approaches relating to radial-flow type vessels employing temperature swing adsorption (“TSA”), in order to minimize or offset the multiple consequences of cyclic thermal expansion and contraction of materials within the adsorption vessel. The U.S. Pat. No. 6,086,659 discloses a welded-closed type vertical adsorption vessel, therein containing multiple radially gas-outward flow vertical beds concentrically-positioned around the vessel center axis positioned cylindrical feed gas delivery chamber into which feed gas is introduced through the top of the vessel. Each described vertical adsorbent bed can contain a different adsorbent material, the containment of each bed being accomplished with the invention described perforated metal bed partition and screen design configuration to withstand thermal expansion and contraction stresses. The final product gas exits the outer-most concentric bed retention screen into the outer annulus gas flow space between the vessel inside diameter and the described outer concentric bed retention screen. The product gas is thereafter withdrawn through the bottom portion of the vessel assembly apparatus. Individual single flanged nozzles are provided and aligned-positioned in the top welded head of the vessel, to enable the filling or empting of each separate individual adsorbent bed. U.S. Pat. No. 6,770,120 discloses a welded-closed type vertical adsorption vessel, therein containing either (1) two radial gas-inward flow connected vertical beds concentrically-positioned around the vessel center axis positioned inner cylindrical product delivery chamber through which the product gas exits from the bottom of the vessel; (2) one radial gas-inward flow connected vertical bed concentrically-positioned around the vessel center axis positioned inner cylindrical volume space that is occupied by a vertical axial-flow adsorption bed receiving a series-connected flow of gases from the upstream radial-flow adsorption bed, with final product gas flow exiting from the bottom of the vertical vessel; or (3) one radial gas-inward flow connected vertical bed concentrically-positioned around the vertical vessel center axis positioned inner cylindrical volume space that can be utilized in one variation as a gas storage tank. U.S. Pat. Nos. 5,674,311, 5,538,544, and 6,334,889 respectively describe methods by which the conventional art PSA and VSA systems' (comprising vertical adsorber vessels and vertically deep adsorbent beds) inherit problems of adsorbent bed temperature gradients, uneven gas flow distribution, and adsorbent bed fluidization can be reduced to improve adsorbent bed efficiencies.
[0013] Those skilled in the art will appreciate that the various approaches to PSA and VSA vessel apparatus separation of gases, contained within the above example patents and other existing published art, predominantly limit themselves to employed vertical vessel apparatus that comprise either vertical axial gas flows or horizontal radial gas flows of gases through a ‘fixed’ vertically disposed bed column of adsorbent material. The described current art vertical vessel configurations share many common limitations that negatively impact the vessel's overall consistent gas product purity, maintenance of operating adsorbent bed uniformity and adsorbent structural form integrity, and economical power consumption. Previous art vessels have not addressed the need for a means to carry out a rapid and economical adsorbent bed removal and replacement as new improved performance adsorbent materials become available, or when the existing adsorbent bed becomes contaminated from a process upstream upset condition that contaminates both the process feed gas supplied to the gas separation vessels and the adsorbent materials contained therein.
[0014] A need exists, therefore, for a horizontal vessel apparatus that can overcome conventional art air or process gas separation vessel apparatus limitations. A need also exists for a vertical vessel apparatus that can overcome conventional art air or process gas separation vessel apparatus limitations. The presented invention gas separation vessel apparatus, and embodiments thereof, satisfy these needs and have the following objectives:
[0015] 1. It is a first objective to significantly reduce the electric power consumption by reducing the air or process gas separation vessel's radial-gas flow adsorbent bed depth, and therefore reduce the gas flow differential pressure across the gas flow bed depth that conventionally requires gas compression power to overcome.
[0016] 2. It is a second objective to provide an air or process gas separation vessel apparatus that greatly reduces the molecular sieve bed gas velocities as are employed within conventional PSA and VSA axial gas flow vertical vessel systems, and further reduce current art radial-gas flow bed velocities, thereby achieving significantly increased feedstock gases ‘residence time’ for gases to permeate into the porous structure of employed molecular sieve adsorbent bed material and decreased potential of “bed fluidization” with accompanying molecular sieve material degrading attrition from occurring.
[0017] 3. It is a third objective to achieve a level of precise quantitative adsorbent placement and desired compaction within each multiple separated adsorbent bed material segments that make up the total employed adsorbent bed material employed with each invention embodied radial-flow bed cartridge subassembly. This degree of adsorption bed placement quality control is not possible with existing art axial flow or radial flow adsorbent beds contained within present art vertical gas separation vessels. This objective can also improve both the uniform adsorbent material's adsorption-desorption performance throughout the invention embodied radial-flow bed cartridge, as well as to further eliminate the potential of “bed fluidization” described in the above second objective.
[0018] 4. It is a fourth objective to provide the means of eliminating conventional PSA or VSA air separation vertical vessel's deep molecular sieve adsorbent beds' operational axial gas flow temperature variance characteristics that can negatively affect the beds' nitrogen adsorbed gas separation efficiencies.
[0019] 5. It is a fifth objective of the present air or process gas separation vessel apparatus described herein, to provide an apparatus can be adaptable to a manufacturer's or system fabricator's chosen selection of adsorbent molecular sieve materials, desired product gas production rate and purity, length and diameter dimensional configurations of vessel assemblies, and the employment of selected embodiments and variations provided by the invention.
[0020] 6. It is a sixth objective that the employed air or process gas separation vessel apparatus have the inherit subassembly design means that can accommodate the long-term operational employment of both present or later added future molecular sieve material adsorbents whose fragile structures can be incompatible with the combined cyclic adsorption-desorption pressure swings and weight bearing loads imposed by conventional vertical adsorber vessel designs having either radial or axial style gas flows through their common configuration of vertically disposed and fixed adsorbent beds.
[0021] All references cited herein are incorporated by reference to the maximum extent allowable by law. To the extent a reference may not be fully incorporated herein, it is incorporated by reference for background purposes and indicative of the knowledge of one of ordinary skill in the art.
SUMMARY
[0022] The invention generally is directed to a vessel apparatus used in gas separation processes employing an adsorbent bed material. More specifically, the invention is directed to apparatus means that includes an air or process gas separation vessel with one or multiple embodied radial-flow bed cartridge-type adsorbent bed subassembly devices contained therein. Hereafter, the adsorbent bed subassembly may be referred to as a “Radial-Flow Bed Cartridge” subassembly, or more simply referred to as a “RFBC subassembly.” The invention embodiment vessel assembly apparatus into which a RFBC subassembly is inserted, may hereafter be referred to more simply as a “RFBC vessel assembly.” One or multiple embodied RFBC subassembly devices can provide the entire designated rated gas adsorption capacity of a gas separation vessel apparatus. The present invention apparatus is distinguished from other art by its embodiments of unique simplified gas separation vessel design and replaceable internal vessel positioned RFBC subassembly devices.
[0023] A first embodiment of the invention responds to a need wherein a horizontal RFBC vessel assembly configuration is particularly suited to, but not limited to, large volume rated air or gas process streams. In this embodiment, the design of the RFBC vessel assembly is specific to the invention installed in a horizontal-axis plane. The horizontal position and design of the vessel permits manageable onsite installation or removal/replacement of individual non-conventional adsorbent bed subassemblies that are typically larger in size and greater in weight when applied to the gas separation of large capacity flow process streams. There can be variances to this first embodiment of the invention, as described later.
[0024] A second embodiment of the invention responds to the need to satisfy the invention's stated objectives that overcome the operational shortcomings that presently exist with present art large capacity air or gas conventional vertical adsorber vessel designs having either radial or axial style gas flows through the adsorbent beds, but both styles having fixed vertically disposed high adsorbent beds. The invention second embodiment comprises a horizontal RFBC subassembly for exclusive employment within the horizontal-positioned first embodiment RFBC vessel assembly.
[0025] A third embodiment of the invention responds to need wherein a vertical RFBC vessel assembly apparatus configuration is particularly suited to, but not limited to, smaller volume rated air or gas process streams. In this embodiment, the design of the RFBC vessel assembly apparatus is specific to the invention installed in a vertical-axis plane. The vertical positioning and vessel vertical design dimensions can permit easily manageable onsite installation or removal/replacement of individual RFBC subassemblies that are typically smaller in size and of lesser weight than those applied within large capacity flow process streams. There can be variances to the third embodiment of the invention, as described later.
[0026] A fourth embodiment of the invention responds to the need to satisfy the invention's stated objectives that overcomes the operational shortcomings that presently exist with present art small to medium air or gas capacity conventional vertical adsorber vessel apparatus designs having either radial or axial style gas flows through the adsorbent beds, wherein both styles have common fixed vertically disposed high adsorbent beds. The fourth embodiment comprises a vertical RFBC subassembly for exclusive employment within vertically-positioned air or gas RFBC vessel assemblies.
[0027] The present invention apparatus embodies a non-conventional art RFBC vessel assembly and a non-conventional art RFBC subassembly that collectively therein achieve all of the fore-described invention's six objectives during PSA or VSA system methods of air or process gas separation, the PSA or VSA methods alternatively comprising controlled gas temperature swings during sequenced adsorption and desorption cycles within each of two conventionally applied parallel trains, each train comprising one or more RFBC vessel assembly.
[0028] Other objects, features, and advantages of the present invention will become apparent with reference to the drawings and detailed description that follow.
BRIEF DESCRIPTION OF THE DRAWINGS
[0029] FIG. 1 is a side view of the invention's first embodiment described horizontal-type RFBC vessel assembly with centerline-position gas connections.
[0030] FIG. 1A is a cross-sectional view of the invention's first embodiment described horizontal-type RFBC vessel assembly with centerline-position gas connections and displayed invention's second embodiment internally-positioned radial-flow bed cartridge RFBC sub-assembly.
[0031] FIG. 2 is a side view of the horizontal-type gas adsorption-desorption vessel 1 with side tangential-position gas connections.
[0032] FIG. 2A is a cross-sectional view of the invention's first embodiment variance employed horizontal-type RFBC vessel assembly with side tangential-position gas connections, and displayed second embodiment internally-positioned RFBC sub-assembly.
[0033] FIG. 3 is a perspective view of an example second embodiment RFBC sub-assembly and communicating positioning devices.
[0034] FIG. 4 is a perspective view for an example of two series-positioned second embodiment RFBC subassemblies and inner-subassembly communicating product gas flow device.
[0035] FIG. 5 is a side view of the invention's third embodiment employed vertical-type RFBC vessel assembly.
[0036] FIG. 6 is a cross-sectional view of the invention's third embodiment employed vertical-type gas RFBC vessel assembly with displayed internally-positioned fourth embodiment RFBC sub-assembly.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0037] In the following detailed description of the preferred embodiments, reference is made to the accompanying drawings which form a part hereof, and in which is shown by way of illustration specific preferred embodiments in which the invention may be practiced. These embodiments are described in sufficient detail to enable those skilled in the art to practice the invention, and it is understood that other embodiments may be utilized and that logical changes may be made without departing from the spirit or scope of the invention. To avoid detail not necessary to enable those skilled in the art to practice the invention, the description may omit certain information known to those skilled in the art. The following detailed description is, therefore, not to be taken in a limiting sense, and the scope of the present invention is defined only by the appended claims.
[0038] The application of the present invention in its following first and second embodiment form is initially disclosed in the inventor's U.S. Pat. No. 6,878,188, issued on Apr. 12, 2005, the teachings of which are incorporated herein by reference in their entirety.
[0039] The invention gas separation vessel apparatus is intended to be primarily employed in PSA and VSA adsorption/desorption gas separation systems, wherein most commonly two parallel trains of vessels (each train comprising one, or two or more parallel vessels) operating together, one train operating in the adsorption cycle mode, while the other train operates in the desorption cycle mode. Each vessel apparatus is designed to alternately function in one described cycle mode before alternating to function in the other cycle mode. Applications to which the invention can be applied include gas separation systems requiring two steps of gas separation that embodies a series-connection of a first PSA or VSA adsorption/desorption gas separation subsystem employing a first adsorbent material in communication with a downstream positioned second PSA or VSA adsorption/desorption gas separation subsystem employing a second adsorbent material of different molecular composition than employed in the first subsystem.
[0040] For larger industrial applications requiring on-site equipment deliveries by conventional over the road flatbed tractor trailers, the horizontal RFBC vessel assemblies may preferably range in diameter between 3 feet to 8 feet and the vessel shell lengths may preferably range between 20 feet to 40 feet. For small commercial to moderate size industrial applications, the vertical RFBC vessel assemblies may preferably comprise, but not limited to, a range in diameters between 1 foot to 4 feet. The vessel shell lengths may preferably comprise, but not limited to, a range of lengths between 2 feet to 10 feet. The vertically disposed depth of adsorbent material within each adsorbent bed segment contained within a single RFBC subassembly, may preferably comprise, but not limited to, a range of depths between 4 inches to 3 feet depending on the application and the ability of the selected adsorbent bead, pellet, or other shape to withstand fracturing or attrition during the long-term applied combined adsorbent weight loads and cycling of gas flows. The radial-flow depth of adsorbent through which a gas flows within a RFBC subassembly embodiment may preferably comprise, but not limited to, a range of depths between 1 inch to 40 inches over a range of small commercial to large industrial gas volume flow rate applications.
[0041] The invention RFBC vessel assembly apparatus can employ within its embodied RFBC subassemblies those absorbents known in the art that are suitable for specific gas pre-conditioning and/or primary process gas separation applications. Examples can include, but are not limited to microporous crystalline zeolite and non-zeolite catalysts, particularly aluminophosphates (AIPO) and silicoaluminophosphates (SAPO), carbon zeolites, other zeolite like materials, activated aluminas, silica gel, other commercially available molecular sieves or mixtures thereof. Commercially available molecular sieve materials suitable for air separation can include, among others, zeolite 4A, 5A, 13X, and various lithium caton forms of zeolite X. The invention provided vessel assembly embodied features are described later that enable rapid and economical on-site conversion to future developed high efficiency adsorbent materials.
[0042] Referring now more particularly to FIG. 1 , the invention's RFBC vessel assembly with outer shell 1 is shown in a first embodiment horizontal side-view position. The RFBC vessel assembly cylindrical body shell material can include either a typical example carbon steel or alloy steel pipe or rolled and welded alloy steel sheet or plate, or alternately commercially available pipe of high density polyethylene (HDPE) grade 3408 extruded pipe of appropriate diameter and SDR number. The material, diameter, and length of the RFBC vessel assembly outer shell 1 will primarily vary with the economical accommodation of desired rated gas separation capacity for each RFBC vessel assembly and the chosen operating pressure and temperature of the adsorbent or molecular sieve material employed within the selected RFBC subassembly. Typically, the RFBC vessel assembly outer shell 1 will have a length to diameter ratio of greater than 2:1.
[0043] RFBC vessel assembly shell flanged inlet gas connections 2 are shown as being of quantity three in number but can be one in number for adsorber assemblies of less than 6 feet in shell length. Gas connections 2 serve as both supply gas connection means for the flow of feedstock gases into the RFBC vessel assembly during the assembly's adsorption sequence operation as well as the connections for the discharge of exhaust flows comprising waste gases extracted from within the RFBC vessel assembly during its desorption sequence operation.
[0044] As shown in FIG. 1 , flanged connections 3 can be welded to both ends of the example RFBC vessel assembly shell 1 . A gasketed blind flange 4 can provide the closure means for one end of the example RFBC vessel assembly. Alternately on one end of an example steel vessel assembly shell 1 , flanged connections 3 and gasketed blind flange 4 may be replaced by one ASME pipe or vessel weld cap. Although a detailed fabrication design of the RFBC vessel assembly is not within the scope of the invention, one or both ends of the RFBC vessel assembly can be provided with a subassembly closure means, which can comprise the comparable elements of a machined blind flange component 5 , a packing or sealing gland component 8 , and a adjustable axial-positioned cylindrical hollow element or pipe 7 with end welded flange 6 . Element 7 extends into the RFBC vessel assembly, therein establishing a gas sealing contact and flow communication with the RFBC sub-assembly's central axial-positioned gas void space 14 as provided by the inside bore of pipe 16 in FIG. 1A and FIG. 2A . As a PSA or VSA desorption operation may require, purge gas can also be emitted into connection 6 for flow passage into the described central axial-positioned gas void space 14 of the RFBC sub-assembly(s) positioned within the RFBC vessel assembly. Any design of similar functioning closure and sealing means can provide the connection and conduit means for the RFBC vessel assembly separated product gas stream flow to be extracted or exhausted from within the RFBC vessel assembly for conduit flow-communication to an employed gas separation system. Said designs of similar functioning closure and sealing means can also be provided as modified commercially available pipe or vessel hinged closure assemblies that are welded to either or both ends of the RFBC vessel assembly shell 1 , therein providing the means for easy installation or change-out of RFBC subassembly(s) contained within the RFBC vessel assembly.
[0045] The FIG. 1 described invention's unique gas RFBC vessel assembly apparatus with end-closure design means can accept the employment of herein described RFBC sub-assembly that can be readily inserted or removed when the gas separation system's feed gas and desired gas product duties change or when more advanced and efficient molecular sieves become available as new products of advanced gas adsorbent technology.
[0046] Referring now more particularly to FIG. 1A therein showing the 1 A- 1 A cross-sectional view of the FIG. 1 RFBC vessel assembly, the flow stream 9 of air or process gas feedstock enters the invention's RFBC vessel assembly apparatus through flange connection 2 . When the RFBC vessel assembly shell diameters are dimensionally greater than 4 feet, flange connections 2 can alternately be positioned on both sides of the vessel assembly shell 1 at example 3 o'clock and 9 o'clock positions. This described positioning of flange connections 2 can facilitate the closely positioned installation of one horizontal RFBC vessel assembly over the top of another horizontally installed RFBC vessel assembly.
[0047] During the gas adsorption sequence of operation, the in-flow of air or process gas feedstock 9 enters the RFBC vessel assembly apparatus through flange connection 2 and the flow of gases are distributed at low gas flow velocities within the outer annular void space 10 surrounding combined adsorbent bed material 13 contained within the one or multiple RFBC subassembly. The flow of air or process gas feedstock 9 within void space 10 flows radially-inward as shown by directional gas flow 12 through perforated corrosion resistant alloy metal cover sheet 11 and inner surface attached corrosion resistant alloy wire mesh or other porous glass fiber or synthetic fiber based media material 19 that collectively secures the outer surface of each wedge-shape adsorbent bed segment 13 positioned within each RFBC subassembly. The air or process gas feedstock flow 12 initial flow velocity into the adsorbent bed 13 of greatly increased surface area is corresponding greatly reduced in velocity, as compared to a conventional PSA or VSA system's vertical vessel's gas velocity from its axial gas flow through an equal volume of bed adsorbent. As the waste gas portions of the feedstock gas are steadily adsorbed during the progressive radially-inward gas flow penetration into each molecular sieve bed segment 13 depth of progressive decreasing cross-section area, the desired product gas flow 14 (high purity oxygen in the case of a preferred pure VSA air separation system) emerges from the inner surface of the adsorbent bed 13 at an approximate continued equal gas flow velocity rate as the feedstock flow 12 gas entry velocity into the adsorbent bed 13 . The product gas further emerges from the adsorbent bed segment 13 and passes through corrosion resistant alloy wire mesh or other porous glass fiber or synthetic fiber based media material 15 and through the perforated or slotted wall of pipe or tubing centerline axis-positioned central core pipe or tubing 16 as the gross product 14 oxygen stream that is subsequently thereafter flow-exhausted from the RFBC vessel assembly through connection 6 shown in FIG. 1 .
[0048] During the RFBC vessel assembly's PSA or VSA desorption sequence of operation (with counter-current directional gas flow to that indicated in FIG. 1A for the adsorption operation), the extracted or exhausted flow of waste gases (contained with the RFBC subassembly adsorbent 13 ) comprise a reverse radially-outward flow of extracted waste gases that enters outer annular flow void space 10 . Thereafter, the combined flow of waste gases within void space 10 exits the RFBC vessel assembly through gas connection 2 in a radial-outward direction. As a concluding portion of the RFBG vessel assembly's desorption operation and prior to the low-end psia desorption operation pressure condition being achieved, a limited flow quantity of produced product gas can be axially introduced through RFBC vessel assembly connection 6 of FIG. 1 into the central axial core pipe or tubing 16 . The flow of purge gas passes through the perforated or slotted openings in pipe or tubing 16 , through described media 15 and adsorbent 13 , and described media 19 and perforated corrosion resistant alloy cover sheet 11 as a resulting mixture of waste gas and product purge gas flowing into outer void space 10 before exiting radially-outward from the from the RFBC vessel assembly through connection 2 . According to a separation system's design, the flow of purge gas into the RFBC vessel assembly may be terminated just prior to the end of the employed system's desorption sequence of operation, or may be continued briefly to establish a system desired level of internal vessel pressure.
[0049] Within a provided inner diameter of vessel shell 1 , the uniform annular gas distribution void space 10 cross-sectional flow area and volume is established by the diameter of the RFBC subassembly, RFBC subassembly centering provided by the projection of the threaded end of pipe 16 alignment with the centerline of cylindrical hollow element or pipe 7 with end welded flange 6 shown in FIG. 2 , and the height of the short-length low surface friction spacer blocks 18 that are appropriately and intermittently spaced longitudinally along the length of the RFBC vessel assembly's inner surface of vessel shell 1 .
[0050] Additional low surface friction spacer blocks 18 can be positioned as required to increase the ease in which the RFBC vessel assembly's RFBG subassemblies can be inserted into or removed from the interior of the horizontal-positioned RFBC vessel assembly.
[0051] Each wedge-shape adsorbent bed segment 13 is established within the cross-section space boundary formed by (a) the combined perforated metal corrosion resistant alloy cover sheet 11 and inner surface attached corrosion resistant alloy wire mesh or other porous glass fiber or synthetic fiber based media material 19 , (b) the adsorbent side-support plate partitions 17 connected to both perforated corrosion resistant alloy cover metal sheet 11 and central axial core pipe or tubing 16 , and (c) an outer diameter arc segment of the centerline axis-positioned central core perforated or slotted pipe or tubing 16 with attached layer of corrosion resistant alloy wire mesh or other porous glass fiber or synthetic fiber based media material 15 . FIG. 1A shows five adsorbent side-support plate partitions 17 . However the quantity of employed partitions 17 can vary preferably between two and twelve depending on the diameter of the RFBC subassembly and the structural strength characteristics of the employed adsorbent material form.
[0052] The inner end surface of each radial partition 17 can be welded to inner pipe 16 , and the outer perforated corrosion resistant alloy metal cover 11 skip-spot-welded to the mating outer end contact surfaces of the radial partition 17 . The longitudinal end surfaces of the radial partitions have mating contact with the inner surfaces of the RFBC subassembly end caps 20 and 21 as shown in the following FIG. 3 and FIG. 4 drawings. The adsorbent volume contained within each adsorbent segment 13 , is therefore established by its cross-section space boundary area and the length of the longitudinal radial partition 17 .
[0053] The corrosion resistant alloy wire mesh or other porous glass fiber or synthetic fiber based media materials 15 and 19 can be positioned and bonded respectively to the outer diameter surface of perforated or slotted inner pipe 16 and the inner surface of perforated metal corrosion resistant alloy outer cover sheet 11 , each positioning further occurring between individual adjacent partitions 17 as joined to inner pipe 16 and to outer cover 11 , with each described media segment being approximately equal to the longitudinal length of the radial partitions 17
[0054] Referring now more particularly to FIG. 2 , the drawing is a variance of the first embodiment of the invention as illustrated in the preceding FIGS. 1 and 1 A drawings, such that like reference characters refer to the same parts throughout the different variance views of the same embodiment.
[0055] A first embodiment variation configuration of the invention RFBC vessel assembly is shown in the side-view FIG. 2 drawing of a RFBC vessel assembly having alternative provided flanged tangential connected gas nozzles 2 welded to vessel shell 1 in lieu the centerline-positioned gas nozzles 2 shown in FIG. 1 . The 2 A- 2 A cross-sectional view of the FIG. 2 RFBC vessel assembly is shown in the FIG. 2A cross-section view drawing. This first embodiment variation can alternatively be employed as a means of optimizing the distribution and efficiency of outer annular space 10 gas flows within the vessel.
[0056] Referring now more particularly to FIG. 3 , the drawing is a 3-dimensional exterior view of the invention embodiment example of a single RFBC subassembly 50 as partially illustrated in the preceding FIG. 1A and FIG. 2A drawings for placement exclusively within the invention respective FIG. 1 or FIG. 2 horizontally installed RFBC vessel assembly. Like reference characters appear in FIG. 3 as they are shown in FIGS. 1, 1A , 2 , and 2 A.
[0057] The cylindrical RFBC subassembly 50 total volume of interior adsorbent bed material closely approximates that of the volume contained within; (a) the outer surface boundary formed by the perforated metal corrosion resistant alloy sheet outer cover 11 with attached corrosion resistant wire mesh or other porous glass fiber or synthetic fiber based media material, (b) male end cap 20 , and female end cap 21 , and (c) the inner surface boundary formed by the outer diameter of perforated pipe or tube 16 with attached outer surface corrosion resistant wire mesh or other porous glass fiber or synthetic fiber based media material 15 .
[0058] The female end cap 21 can be first connected to the outer cylindrical formed perforated metal corrosion resistant alloy sheet outer cover 11 by means of bonding, fusion, or other means. The inner pipe 16 can be machine threaded on both ends, with the pipe passing first through the center of end caps 21 , followed later in assembly by passing through end cap 20 .
[0059] On the female end cap 21 end of the RFBC subassembly, the inner pipe 16 end (not visible in this view) passing through the end cap 21 is sealed closed with a pipe cap 26 , which further provides a means of: (a) securing the ends of the fore-described adsorbent bed partitions 17 to the interior face of end cap 21 , (b) placing the RFBC subassembly in sealing compression (following installation of the adsorbent material) with the installation of male end cap 20 and tightening of hex nut 22 on other inner pipe end 16 . Installation of threaded coupling 25 on the remaining threaded portion of inner pipe end 16 provides the means for the RFBC subassembly product gas flow to be flow communicated into the RFBC vessel assembly's adjustable axial-positioned and threaded cylindrical hollow element or pipe 7 with end welded flange 6 as shown in FIG. 1 and FIG. 2 drawings. When the RFBC subassembly is installed within the RFBC vessel assembly as shown in FIG. 1 and FIG. 2 , one end of spring 27 is in contact with the end cap 21 , and the other end is in spring compression contact with RFBC vessel assembly blind flange 4 as shown in FIG. 1 and FIG. 2 .
[0060] Referring now more particularly to FIG. 4 , the drawing is a 3-dimensional exterior view of the invention embodiment example of two series-positioned RFBC subassemblies as positioned together within the invention RFBC vessel assembly. Like reference characters appear in FIG. 4 as they are shown in the FIG. 3 drawings. The presented example of two series-positioned and identically constructed RFBC subassembly, that can be can be employed within RFBC vessel assembly embodiment FIGS. 1, 1A , 2 , and 2 A, are typical also of greater than two series-connected RFBC subassembly that can be installed within the invention first embodiment described RFBC vessel assembly. With the FIG. 4 RFBC subassembly being of similar construction to that presented in the FIG. 3 RFBC subassembly, the following additional FIG. 4 description details pertains primarily to the presented RFBC subassembly features that have been provided exclusively for the viable application of common multiple series-positioned RFBC subassembly within a single RFBC vessel assembly.
[0061] Each presented RFBC subassembly contains a male end cap 20 with male ‘lugs’ identified as 20 a , 20 b , and 20 c . To maintain a common alignment of all series-connected and identically constructed RFBC subassembly as they are installed within a common RFBC vessel assembly, each male lug 20 a , 20 b , and 20 c is aligned with and inserted into the preceding installed RFBC subassembly female end cap 21 having identically aligned respective female lug inserts 21 a , 21 b (not shown), and 21 c . A soft compressible RFBC subassembly transition gas seal 28 is provided for the connecting of gas flows 14 between each RFBC subassembly's inner pipe 16 . The inner diameter of the transition gas seal 28 is slightly greater than the hex head nut 22 point-to-point hex dimension, and the outside diameter dimension provides sufficient resultant gas seal face contact with end caps 20 and 21 . The uncompressed height of the seal is slightly greater than the combined heights of the recessed face depths of end caps 20 and 21 in direct contact with each other.
[0062] During the assembly of the RFBC subassembly, the male lug 20 b on male end cap 20 and female lug recess 21 b on end cap 21 are positioned to be in the 6 o'clock position as coinciding with the thickest bed partition 17 as shown in FIGS. 1A and 2A drawings. From the insertion of the RFBC subassembly (internally having the thickest bed partition 17 in the 6 o'clock position) into the RFBC vessel assembly, a large diameter and long RFBC subassembly will have the greatest resistance to bending moments created by the weight of the adsorbent material contained within the RFBC subassembly. The intermittent longitudinal spacing of anti-friction blocks 18 within the inside diameter of the vessel shell 1 (as shown in FIGS. 1A and 1B drawings), provides additional means of minimizing bending stresses within the RFBC subassembly. On both the male end cap 20 and female end cap 21 A, a partially completed drilled hole 23 is furnished at the 12 o'clock position, as a vertical position reference to enable the proper positioning of the RFBC subassembly position within the RFBC vessel assembly. In future applications when new highly efficiency semi-conducting porous synthetic molecular sieve adsorbents become commercially available, partially drilled hole location 23 in end caps 20 and 21 will be replaced by an incorporated internal female-end electrical connector (not shown), electrically connected to future supplied electrode means (not shown) distributed through each previously described RFBC subassembly adsorbent bed segment 13 . Male electrical pin connector 24 shall electrically connect one series-positioned RFBC subassembly to the other adjacent series-positioned RFBC subassembly. The future inserted and partially exposed electrical pin connector 24 projecting from each end cap that is not connected with an adjacent series-connected end cap, can in the future be electrically cable-connected to a controlled intrinsically-safe source of control power within electrical conduit boxes 40 shown in FIGS. 1, 2 , and 5 .
[0063] Referring now more particularly to FIG. 5 , a side view is shown of the invention's third embodiment employed vertical-type gas adsorption-desorption vessel with flanged-pipe gas connections 33 and 34 radially-positioned to the vertical centerline of the vessel and welded to the outer vessel shell 29 . For those skilled in the art, it will be readily apparent that the invention's third embodiment of a vertical vessel can also be configured with vessel tangential gas connections as shown in FIG. 2 . A vessel mounting cylindrical base plate 32 is welded to the bottom end of outer shell 29 , and upper vessel bolted flange 31 welded to the upper end of outer shell 29 . A welded threadolet-type coupling 39 is attached to the vessel shell for future installation of electrical conduit box 40 . A blind flange vessel gasketed cover plate 30 is bolted to flange 31 to form a gas tight vessel end seal. A variance to the cover plate 30 and flange 31 can comprise a commercially available pipe or vessel hinged closure assembly that is welded to the upper end of the RFBC vessel assembly shell 29 .
[0064] Referring now more particularly to FIG. 6 , the FIG. 6 drawing shows the 6 - 6 cross-sectional view of the FIG. 5 RFBC vessel assembly. The FIG. 6 cross-sectional view shows the invention's fourth embodiment RFBC subassembly as predominantly having identical identified external and internal components to those of the invention's second embodiment as presented in the FIG. 3 RFBC subassembly 50 , and FIG. 1A and FIG. 2A . The invention fourth embodiment shown RFBC subassembly varies from the second embodiment RFBC subassembly in the manner and device by which one internal adsorbent bed segment 13 is internally partitioned from another adjacent adsorbent bed segment 13 . In a like manner, the invention's fourth embodiment RFBC subassembly can be series connected to another RFBC subassembly as shown in FIG. 4 subassembly view 60 for installation within a single RFBC vessel assembly.
[0065] The flow stream 37 of air or process gas feedstock enters the invention's RFBC vessel assembly apparatus through flange connection 33 that is welded to the RFBC vessel assembly outer shell 29 . When the RFBC vessel assembly shell diameters are dimensionally greater than 4 feet, flange connections 33 can alternately be positioned on both sides of the adsorber assembly shell 29 . This described positioning of flange connections 33 on larger diameter vessels can facilitate the flows of feed gas into the vessel during the adsorption operation sequence and the exiting of waste gases during the desorption operation sequence of gas separation. During the gas adsorption sequence of operation, the in-flow of air or process gas feedstock 37 enters the RFBC vessel assembly apparatus through flange connection 33 and the flow of gases are distributed at low gas flow velocities within the outer annular void space 10 surrounding RFBC subassembly 60 as further described later. The introduced flow of air or process gas feedstock 37 within void space 10 flows radially-inward as shown by directional gas flow 12 through perforated metal corrosion resistant alloy cover sheet 11 and inner surface attached corrosion resistant alloy wire mesh or other porous glass fiber or synthetic fiber based media material 19 that collectively secures the outer porous wall of each cylindrical adsorbent bed segment 13 as positioned within each radial-flow cartridge subassembly. The initial air or process gas feedstock flow velocity of gases 12 into the adsorbent bed 13 of greatly increased surface area is corresponding greatly reduced in velocity, as compared to a conventional PSA or VSA system's vertical vessel's gas velocity from its axial gas flow through an equal volume of adsorbent bed. As the waste gas portions of the feedstock gas are steadily adsorbed during the progressive radially-inward gas flow 12 penetration into each adsorbent bed segment 13 depth having a decreasing cross-sectional area, the desired product gas flow 14 that enters into the interior of pipe 16 (high purity oxygen in the case of a preferred type VSA air separation system) emerges from the inner surface of the adsorbent bed 13 at an approximate continued equal gas flow velocity rate as the feedstock flow 12 gas entry velocity into the adsorbent bed 13 .
[0066] The product gas emerging from the adsorbent bed segments 13 passes through corrosion resistant alloy wire mesh or other porous glass fiber or synthetic fiber based media material 15 and through the perforated or slotted wall of pipe or tubing centerline axis-positioned central core pipe or tubing 16 as the total gross product 14 oxygen stream that is subsequently thereafter flow-exhausted from the lower portion of the RFBC vessel assembly as gas product stream 38 through pipe connection 34 . One skilled in the art will readily recognize that the invention is not limited to oxygen separation, but can be adapted to separate other desired gases.
[0067] During the RFBC vessel assembly's PSA or VSA desorption sequence of operation (with counter-current directional gas flow to that indicated in FIG. 6 for the adsorption operation), the extraction flow of waste gases (contained with the RFBC subassembly adsorbent 13 and RFBC vessel assembly outer annular void space 10 ) comprise a reverse radially-outward flow of extracted or exhausted waste gases that collectively exits through connection 33 . Prior to the low-end psia desorption operation pressure condition being achieved, a limited flow quantity of produced product gas can be axially introduced through RFBC vessel assembly connection 34 into the central axial core pipe or tubing 16 . The flow of purge gas passes through the perforated or slotted openings in pipe or tubing 16 and attached wire mesh or other porous glass fiber or synthetic fiber based media material 15 into the RFBC subassembly adsorbent 13 for a contributed and continued radially-outward flow of mixed waste gases and purge gases that passes through adsorbent bed 13 and then through corrosion resistant alloy wire mesh or other porous glass fiber or synthetic fiber based media material 19 and perforated metal corrosion resistant alloy cover sheet 11 into outer void space 10 before exiting from the from the RFBC vessel assembly through connection 33 in a counter-current direction to the FIG. 6 shown feedstock gas supply stream 37 employed for the adsorption operation. The flow of purge gas into the RFBC vessel assembly can be terminated just prior to the end of the employed system's designed desorption sequence of operation, or can be continued briefly to establish a system desired degree of internal vessel pressure.
[0068] Within a provided inner diameter of vessel shell 29 , the annular gas distribution void space 10 cross-sectional flow area and volume is established by the diameter of the example RFBC subassembly 50 ( FIG. 3 ), and proper RFBC subassembly centering provided by the combined lower RFBC subassembly projection of the threaded end of pipe 16 passing through the RFBC vessel assembly bottom plate 36 at the vessel's vertical centerline position and the outer face of end cap 21 compression contact on the horizontal bottom plate 36 of the RFBC vessel assembly.
[0069] Whereas FIG. 6 shows a single invention fourth embodiment RFBC subassembly whose total adsorbent bed as divided into two example bed segments, each hollow core cylindrical adsorbent bed segment 13 is established within the volumetric boundary formed by: (a) the combined perforated metal corrosion resistant alloy cover sheet 11 and inner surface attached corrosion resistant alloy wire mesh or other porous glass fiber or synthetic fiber based media material 19 , (b) a circular metal intermediate diaphragm adsorbent support partition 35 either fastened, bonded, or fused to both perforated metal corrosion resistant alloy cover sheet 11 and the central axial core pipe or tubing 16 , (c) the interior surface of end caps 20 or 21 , and (d) central axial core pipe or tubing 16 and outer surface attached corrosion resistant wire mesh or other porous glass fiber or synthetic fiber based media material 15 . In the case wherein the RFBC subassembly total adsorbent bed is divided into three or more (not shown) bed segments 13 , each additional adsorbent bed segment 13 would be positioned between the two fore-described adsorbent bed segments 13 . Each additional hollow core cylindrical adsorbent bed segment 13 volumetric boundary then would be formed by the combined: (a) perforated metal corrosion resistant alloy cover sheet 11 and inner surface attached corrosion resistant wire mesh or other porous glass fiber or synthetic fiber based media material 19 , (b) central axial core pipe or tubing 16 outer surface attached corrosion resistant wire mesh or other porous glass fiber or synthetic fiber based media material 15 , (c) a top and bottom circular solid metal adsorbent intermediate support tray partition 35 , either fastened, bonded, or fused to both perforated metal corrosion resistant alloy cover sheet 11 and the central axial core pipe or tubing 16 .
[0070] Male end cap 20 and female end cap 21 maintain a compression contact on the assembly method provided precisely pre-compacted adsorbent bed segments 13 and the outer perforated metal corrosion resistant alloy cover sheet 11 from the applied tightening of the machine thread hex head nuts 22 on both ends of pipe 16 and in compression contact with the end caps recessed face surfaces. Following assembly, either or both end caps may undergo a heat fusion or bonding action for permanently mating to the outer perforated metal corrosion resistant alloy cover sheet 11 portions that are recessed partially into each end cap. The portion of threaded pipe end 16 extending above the face of end cap 20 is closed and sealed with the installation of machine thread pipe cap 26 . Upon closure of the top portion of the vertical RFBC vessel assembly from the installation of top gasketed cover plate 30 , spring 27 installed around pipe cap 26 exerts a compression securing force on the top of the RFBC subassembly 50 . The fore-described bottom vessel horizontal plate 36 is welded to the inside surface of vessel shell 29 , and one end of cylindrical support member 41 having multiple support wall circular hole gas passageways 42 is welded to plate 36 . The other end of pipe 36 maintains surface contact with the horizontal vessel floor mounting plate 32 welded to the lower end of vessel shell 29 .
[0071] FIG. 6 does not show all identified described end cap 20 and end cap 21 details presented for FIG. 3 and FIG. 4 drawings, nor the presented provisions for future applications when new highly efficiency semi-conducting porous synthetic molecular sieve adsorbents become commercially available. These details are however included by reference to the FIG. 6 descriptive references to FIG. 3 and FIG. 4 .
[0072] While the invention has been particularly shown and described with references to preferred employed embodiments of single RFBC subassembly or series-connected RFBC subassemblies positioned within a RFBC vessel assembly in order to simplify the described and visually presented invention, it is appreciated that apparatus variations may be made to best adapt the invention to varied gas capacity rated separation applications. It will be additionally understood by those skilled in the art and having familiarity with conventional art natural gas particulate and coalescing filter separators, that highly economical standardized designed production line quantities of multiple small diameter filter cartridge elements may be parallel-positioned within a vessel assembly with their centerlines concentrically arranged about the centerline of the vessel. A similar described parallel arrangement of smaller diameter RFBC subassemblies can be employed as an economically viable and desirable variance to the second and fourth embodiment of RFBC subassemblies and their placement within their respective first and third embodiment RFBC vessel assemblies, without departing from the scope and spirit of the invention.
[0073] While this invention has been particularly described with references to the embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the scope of the invention encompassed by the appended claims. | An improved gas separation vessel apparatus is provided. The gas separation vessel apparatus is adapted to separate oxygen and other process gases, and it employs both vertically-, or alternatively, horizontally-positioned vessels. The gas separation vessels disclosed contain removable radial-flow bed cartridge-type adsorbent subassemblies, which may be replaced, substituted, or serviced with minimal system down time. | 1 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present application is a nonprovisional and claims the benefit of 60/687118, filed Jun. 2, 2005 and 60/751092 filed Dec. 15, 2005, both incorporated by reference in their entirety for all purposes.
STATEMENT OF GOVERNMENT INTEREST
[0002] The work described in this application was funded in part by Grants 1R43CA101283-01A1 and RO1 NS32148 from the National Institutes of Health. The U.S. government may have certain rights in this invention.
FIELD OF THE INVENTION
[0003] The present invention relates generally to treatment of brain tumors with antibodies and more particularly, for example, to treatment of brain tumors with monoclonal antibodies that bind to and neutralize Hepatocyte Growth Factor.
BACKGROUND OF THE INVENTION
[0004] Human Hepatocyte Growth Factor (HGF) is a multifunctional heterodimeric polypeptide produced by mesenchymal cells. HGF has been shown to stimulate angiogenesis, morphogenesis and motogenesis, as well as the growth and scattering of various cell types (Bussolino et al., J. Cell. Biol. 119: 629, 1992; Zarnegar and Michalopoulos, J. Cell. Biol. 129:1177, 1995; Matsumoto et al., Ciba. Found. Symp. 212:198, 1997; Birchmeier and Gherardi, Trends Cell. Biol. 8:404, 1998; Xin et al. Am. J. Pathol. 158:1111, 2001). The pleiotropic activities of HGF are mediated through its receptor, a transmembrane tyrosine kinase encoded by the proto-oncogene cMet. In addition to regulating a variety of normal cellular functions, HGF and its receptor c-Met have been shown to be involved in the initiation, invasion and metastasis of tumors (Jeffers et al., J. Mol. Med. 74:505, 1996; Comoglio and Trusolino, J. Clin. Invest. 109:857, 2002). HGF/cMet are coexpressed, often over-expressed, on various human solid tumors including tumors derived from lung, colon, rectum, stomach, kidney, ovary, skin, multiple myeloma and thyroid tissue (Prat et al., Int. J. Cancer 49:323, 1991; Chan et al., Oncogene 2:593, 1988; Weidner et al., Am. J. Respir. Cell. Mol. Biol. 8:229, 1993; Derksen et al., Blood 99:1405, 2002). HGF acts as an autocrine (Rong et al., Proc. Natl. Acad. Sci. USA 91:4731, 1994; Koochekpour et al., Cancer Res. 57:5391, 1997) and paracrine growth factor (Weidner et al., Am. J. Respir. Cell. Mol. Biol. 8:229, 1993) and anti-apoptotic regulator (Gao et al., J. Biol. Chem. 276:47257, 2001) for these tumors. Thus, antagonistic molecules, for example antibodies, blocking the HGF-cMet pathway potentially have wide anti-cancer therapeutic potential.
[0005] HGF is a 102 kDa protein with sequence and structural similarity to plasminogen and other enzymes of blood coagulation (Nakamura et al., Nature 342:440, 1989; Weidner et al., Am. J. Respir. Cell. Mol. Biol. 8:229, 1993, each of which is incorporated herein by reference). Human HGF is synthesized as a 728 amino acid precursor (preproHGF), which undergoes intracellular cleavage to an inactive, single chain form (proHGF) (Nakamura et al., Nature 342:440, 1989; Rosen et al., J. Cell. Biol. 127:1783, 1994). Upon extracellular secretion, proHGF is cleaved to yield the biologically active disulfide-linked heterodimeric molecule composed of an α-subunit and β-subunit (Nakamura et al., Nature 342:440, 1989; Naldini et al., EMBO J. 11:4825, 1992). The a-subunit contains 440 residues (69 kDa with glycosylation), consisting of the N-terminal hairpin domain and four kringle domains. The β-subunit contains 234 residues (34 kDa) and has a serine protease-like domain, which lacks proteolytic activity. Cleavage of HGF is required for receptor activation, but not for receptor binding (Hartmann et al., Proc. Natl. Acad. Sci. USA 89:11574, 1992; Lokker et al., J. Biol. Chem. 268:17145, 1992). HGF contains 4 putative N-glycosylation sites, 1 in the α-subunit and 3 in the β-subunit. HGF has 2 unique cell specific binding sites: a high affinity (Kd=2×10-10 M) binding site for the cMet receptor and a low affinity (Kd=10-9 M) binding site for heparin sulfate proteoglycans (HSPG), which are present on the cell surface and extracellular matrix (Naldini et al., Oncogene 6:501, 1991; Bardelli et al., J. Biotechnol. 37:109, 1994; Sakata et al., J. Biol. Chem., 272:9457, 1997). NK2 (a protein encompassing the N-terminus and first two kringle domains of the α-subunit) is sufficient for binding to cMet and activation of the signal cascade for motility, however the full length protein is required for the mitogenic response (Weidner et al., Am. J. Respir. Cell. Mol. Biol. 8:229, 1993). HSPG binds to HGF by interacting with the N terminus of HGF (Aoyama, et al., Biochem. 36:10286, 1997; Sakata, et al., J. Biol. Chem. 272:9457, 1997). Postulated roles for the HSPG-HGF interaction include the enhancement of HGF bioavailability, biological activity and oligomerization (Bardelli, et al., J. Biotechnol. 37:109,1994; Zioncheck et al., J. Biol. Chem. 270:16871, 1995).
[0006] cMet is a member of the class IV protein tyrosine kinase receptor family. The full length cMet gene was cloned and identified as the cMet proto-oncogene (Cooper et al., Nature 311:29, 1984; Park et al., Proc. Natl. Acad. Sci. USA 84:6379, 1987). The cMet receptor is initially synthesized as a single chain, partially glycosylated precursor, p170(MET) ( FIG. 1 ) (Park et al., Proc. Natl. Acad. Sci. USA 84:6379, 1987; Giordano et al., Nature 339:155, 1989; Giordano et al., Oncogene 4:1383, 1989; Bardelli et al., J. Biotechnol. 37:109, 1994). Upon further glycosylation, the protein is proteolytically cleaved into a heterodimeric 190 kDa mature protein (1385 amino acids), consisting of the 50 kDa α-subunit (residues 1-307) and the 145 kDa β-subunit. The cytoplasmic tyrosine kinase domain of the β-subunit is involved in signal transduction.
[0007] Several different approaches have been investigated to attempt to obtain an effective antagonistic molecule of HGF/cMET: truncated HGF proteins such as NK1 (N terminal domain plus kringle domain 1; Lokker et al., J. Biol. Chem. 268:17145, 1993), NK2 (N terminal domain plus kringle domains 1 and 2; Chan et al., Science 254:1382, 1991) and NK4 (N-terminal domain plus four kringle domains; Kuba et al., Cancer Res. 60:6737, 2000) and anti-cMet mAbs (Dodge, Master's Thesis, San Francisco State University, 1998).
[0008] Most recently, Cao et al. (Proc. Natl Acad. Sci. USA. 98: 7443, 2001, which is incorporated herein by reference) reported that administration of a combination of 3 mAbs to HGF inhibited growth of subcutaneous glioma xenografts in mice. WO 2005/017107 A2, which is herein incorporated by reference in its entirety for all purposes, reported that treatment with a single anti-HGF mAb could inhibit growth of subcutaneous glioma xenografts in mice. However, these publications did not address the question of whether systemic administration of an anti-HGF or other mAb can inhibit growth of a tumor in the brain, where the blood-brain barrier presents obstacles (Rich et al., Nat. Rev. Drug Discov. 3: 430, 2004). Indeed, previously observed inefficacy of systemic antibody therapies against central nervous system (CNS) tumors has been attributed to restricted vascular permeability even for CNS metastases (Bendell et al., Cancer 97: 2972, 2003).
[0009] Thus, there is a need for a method to treat brain tumors by systemic administration of a mAb. The present invention fulfills this and other needs.
BRIEF SUMMARY OF THE INVENTION
[0010] In one embodiment, the invention provides a method of treating a brain tumor in a patient by systemic administration of a mAb. The brain tumor may be a glioma such as an astrocytoma, e.g., a glioblastoma. Administration may be, for example, by intravenous, intramuscular or subcutaneous routes. In a preferred embodiment, the mAb is a neutralizing mAb to Hepatocyte Growth Factor (HGF) such as a humanized L2G7 mAb. In another preferred embodiment, systemic administration of a mAb such as a neutralizing anti-HGF mAb is used to induce regression of a brain tumor.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] FIG. 1 . Binding and blocking activities of anti-HGF mAbs measured by ELISA. A. For binding, mAbs were captured onto a goat anti-mouse IgG coated ELISA plate, blocked with BSA and incubated with HGF-Flag (1 μg/ml), followed by HRP-M2 anti-Flag mAb (Invitrogen). B. For blocking of HGF-Flag to Met-Fc binding, plates were coated with goat anti-human IgG-Fc, blocked with BSA, incubated with Met-Fc (2 μg/ml), and then with HGF-Flag (1 μg/ml)±anti-HGF mAbs. The bound HGF-Flag bound was detected with HRP-M2 anti-Flag mAb.
[0012] FIG. 2 . Blocking effects of mAb L2G7 on the scattering, mitogenic, angiogenic, and anti-apoptotic activities of HGF. A. MDCK cells (ATCC) were stimulated with 50 ng/ml of HGF±10 μg/ml L2G7 for 2 days as described (Cao et al., Proc. Natl Acad. Sci. USA. 98: 7443, 2001). Photographs were taken at 100× magnification after the cells were stained with crystal violet. B. Mv 1 Lu mink lung epithelial cells (ATCC;5×104 cells/ml) were incubated in serum free DMEM with or without HGF (50 ng/ml ) and L2G7 or isotype-matched control mAb (mIgG) for 24 hr, and the level of cell proliferation determined by addition of 3H-thymidine for 6 hr. C. As described (Xin et al. Am. J. Pathol. 158, 1111, 2001), HUVEC (CAMBREX; 104 cells/100 μl/well) were incubated in EBM-2/0.1% FCS with or without HGF (50 ng/ml) and L2G7 or control mAb for 72 hr and the level of proliferation determined by the addition of WST-1. D. As described (Xin et al. Am. J. Pathol. 158, 1111, 2001), HUVEC (6×104 cells/100 μl/well) in DMEM/gel were overlayed with 100 μl/well of EMB-2/0.1% FCS/0.1% BSA with or without 200 ng/ml of HGF±20 μg/ml of L2G7. After 48 hr incubation, cells were fixed and stained using toluidine blue and photographs taken at 40× magnification. E. As described (Fan et al. Oncogene 24: 1749, 2005), U87 tumor cells in serum free DMEM were treated with or without HGF (20 ng/ml)±mAb L2G7 (20 μg/ml) or isotype control antibody (mIgG) for 48 hr and then with anti-Fas mAb CH-11 (Upstate Biotechnology, 40 ng/ml) for 24 hr, and cell viability determined by the addition of WST-1. In b, c and e, values are mean±s.d.
[0013] FIG. 3 . Inhibition or regression of glioma tumor xenografts by L2G7. U118 (A) or U87 (B) glioma tumor cells were implanted subcutaneously into NIH III Beige/Nude mice and tumor size monitored as described (Kim et al., Nature 362: 841, 1993). After tumor size had reached ˜50 mm3, groups of mice (n=6 or 7) were treated twice weekly i.p. with 50 or 100 μg L2G7 or 100 μg isotype-matched control mAb (mIgG) or PBS as indicated; arrows show first day of treatment. Values are mean tumor volume±s.e.m. C. U87 tumor cells (105 per mouse) were injected intracranially into the caudate/putamen of Scid/beige mice as described (Abounader et al. FASEB J. 16, 108, 2002). Starting and ending respectively on day 5 and day 52 as indicated by arrows, groups of mice (n=10) were administered i.p. 100 μg L2G7 or PBS twice weekly and survival monitored. Survival studies were analyzed by Kaplan-Meier plots. D. Brain sections prepared as described (Abounader et al. FASEB J. 16, 108, 2002) from representative mice sacrificed on day 21 after 3 doses of twice weekly i.p. treatment with 100 μg L2G7 or PBS, showing size of U87 intracranial xenografts. E. Intracranial U87 tumor volumes in individual mice on Day 18 before starting treatment and on Day 29 after treatment 3 times with L2G7. F. Brain sections from representative mice on Day 18 before treatment and on Day 29 after treatment with L2G7 or control mAb.
[0014] FIG. 4 . Histological analysis of brain sections from mice with U87 intracranial xenografts. The mice were sacrificed after treatment of pre-established tumors with three twice-weekly doses of L2G7 or control. Perfusion-fixed cryostat sections were stained with H&E and the indicated antibody and indexes quantified using computer-assisted image analysis. A. Anti-Ki67 (DAKO) to detect proliferating cells. B. Anti-laminin (Life Technologies) to detect blood vessels. C. Antibody to cleaved caspase-3 (Cell Signaling Technology) to detect apoptotic tumor cell responses.
DETAILED DESCRIPTION OF THE INVENTION
[0015] The invention provides a method of treating brain tumors by systemic administration of a neutralizing mAb to HGF or antibodies against other cytokines such as growth factors or against cell surface proteins such as cytokine receptors. Although an understanding of mechanism is not required for practice of the invention, it is believed that the success of the invention resides at least in part due to passage of antibody from the blood into brain tumors due to a defective blood brain barrier within the tumors.
[0000] 1. Antibodies
[0016] Antibodies are very large, complex molecules (molecular weight of ˜150,000 or about 1320 amino acids) with intricate internal structure. A natural antibody molecule contains two identical pairs of polypeptide chains, each pair having one light chain and one heavy chain. Each light chain and heavy chain in turn consists of two regions: a variable (“V”) region involved in binding the target antigen, and a constant (“C”) region that interacts with other components of the immune system. The light and heavy chain variable regions fold up together in 3-dimensional space to form a variable region that binds the antigen (for example, a receptor on the surface of a cell). Within each light or heavy chain variable region, there are three short segments (averaging 10 amino acids in length) called the complementarity determining regions (“CDRs”). The six CDRs in an antibody variable domain (three from the light chain and three from the heavy chain) fold up together in 3-D space to form the actual antibody binding site which locks onto the target antigen. The position and length of the CDRs have been precisely defined. Kabat, E. et al., Sequences of Proteins of Immunological Interest, U.S. Department of Health and Human Services, 1983, 1987. The part of a variable region not contained in the CDRs is called the framework, which forms the environment for the CDRs.
[0017] A monoclonal antibody (mAb) is a single molecular species of antibody and therefore does not encompass polyclonal antibodies produced by injecting an animal (such as a rodent, rabbit or goat) with an antigen, and extracting serum from the animal. A humanized antibody is a genetically engineered (monoclonal) antibody in which the CDRs from a mouse antibody (“donor antibody”, which can also be rat, hamster or other similar species) are grafted onto a human antibody (“acceptor antibody”). Humanized antibodies can also be made with less than the complete CDRs from a mouse antibody (e.g., Pascalis et al., J. Immunol. 169:3076, 2002). Thus, a humanized antibody is an antibody having CDRs from a donor antibody and variable region framework and constant regions from a human antibody. In addition, in order to retain high binding affinity, at least one of two additional structural elements can be employed. See, U.S. Pat. No. 5,530,101 and 5,585,089, each of which is incorporated herein by reference, which provide detailed instructions for construction of humanized antibodies.
[0018] In the first structural element, the framework of the heavy chain variable region of the humanized antibody is chosen to have maximal sequence identity (between 65% and 95%) with the framework of the heavy chain variable region of the donor antibody, by suitably selecting the acceptor antibody from among the many known human antibodies. In the second structural element, in constructing the humanized antibody, selected amino acids in the framework of the human acceptor antibody (outside the CDRs) are replaced with corresponding amino acids from the donor antibody, in accordance with specified rules. Specifically, the amino acids to be replaced in the framework are chosen on the basis of their ability to interact with the CDRs. For example, the replaced amino acids can be adjacent to a CDR in the donor antibody sequence or within 4-6 angstroms of a CDR in the humanized antibody as measured in 3-dimensional space.
[0019] A chimeric antibody is an antibody in which the variable region of a mouse (or other rodent) antibody is combined with the constant region of a human antibody; their construction by means of genetic engineering is well-known. Such antibodies retain the binding specificity of the mouse antibody, while being about two-thirds human. The proportion of nonhuman sequence present in mouse, chimeric and humanized antibodies suggests that the immunogenicity of chimeric antibodies is intermediate between mouse and humanized antibodies. Other types of genetically engineered antibodies that may have reduced immunogenicity relative to mouse antibodies include human antibodies made using phage display methods (Dower et al., WO91/17271; McCafferty et al., WO92/001047; Winter, WO92/20791; and Winter, FEBS Lett. 23:92, 1998, each of which is incorporated herein by reference) or using transgenic animals (Lonberg et al., WO93/12227; Kucherlapati WO91/10741, each of which is incorporated herein by reference).
[0020] As used herein, the term “human-like” antibody refers to a mAb in which a substantial portion of the amino acid sequence of one or both chains (e.g., about 50% or more) originates from human immunoglobulin genes. Hence, human-like antibodies encompass but are not limited to chimeric, humanized and human antibodies. As used herein, a “reduced-immunogenicity” antibody is one expected to have significantly less immunogenicity than a mouse antibody when administered to human patients. Such antibodies encompass chimeric, humanized and human antibodies as well as antibodies made by replacing specific amino acids in mouse antibodies that may contibute to B- or T-cell epitopes, for example exposed residues (Padlan, Mol. Immunol. 28:489, 1991). As used herein, a “genetically engineered” antibody is one for which the genes have been constructed or put in an unnatural environment (e.g., human genes in a mouse or on a bacteriophage) with the help of recombinant DNA techniques, and would therefore, e.g., not encompass a mouse mAb made with conventional hybridoma technology.
[0021] The epitope of a mAb is the region of its antigen to which the mAb binds. Two antibodies bind to the same or overlapping epitope if each competitively inhibits (blocks) binding of the other to the antigen. That is, a 1×, 5×, 10×, 20× or 100× excess of one antibody inhibits binding of the other by at least 50% but preferably 75%, 90% or even 99% as measured in a competitive binding assay (see, e.g., Junghans et al., Cancer Res. 50:1495, 1990, which is incorporated herein by reference). Alternatively, two antibodies have the same epitope if essentially all amino acid mutations in the antigen that reduce or eliminate binding of one antibody reduce or eliminate binding of the other. Two antibodies have overlapping epitopes if some amino acid mutations that reduce or eliminate binding of one antibody reduce or eliminate binding of the other.
[0000] 2. Neutralizing Anti-HGF Antibodies
[0022] A monoclonal antibody (mAb) that binds HGF (i.e., an anti-HGF mAb) is said to neutralize HGF, or be neutralizing, if the binding partially or completely inhibits one or more biological activities of HGF (i.e., when the mAb is used as a single agent). Among the biological properties of HGF that a neutralizing antibody may inhibit are the ability of HGF to bind to its cMet receptor, to cause the scattering of certain cell lines such as Madin-Darby canine kidney (MDCK) cells; to stimulate proliferation of (i.e., be mitogenic for) certain cells including hepatocytes, 4MBr-5 monkey epithelial cells, and various human tumor cells; or to stimulate angiogenesis, for example as measured by stimulation of human vascular endothelial cell (HUVEC) proliferation or tube formation or by induction of blood vessels when applied to the chick embryo chorioallantoic membrane (CAM). Antibodies used in the invention preferably bind to human HGF, i.e., to the protein encoded by the GenBank sequence with Accession number D90334. Similarly, a neutralizing, i.e., antagonist antibody against any cytokine or cytokine receptor may inhibit binding of the cytokine to the receptor and/or inhibit transmission of a signal to the cell by the cytokine. If the cytokine is a growth factor, such an antibody may inhibit proliferation of cells induced by the cytokine.
[0023] A neutralizing mAb used in the invention typically inhibits at a concentration of, e.g., 0.01, 0.1, 0.5, 1, 2, 5, 10, 20 or 50 μg/ml a biological function of a cytokine, e.g., HGF (for example., stimulation of proliferation or angiogenesis) by about at least 50% but preferably 75%, more preferably by 90% or 95% or even 99%, and most preferably approximately 100% (essentially completely) as assayed by methods described under Examples or known in the art. Typically, the extent of inhibition is measured when the amount of cytokine used is just sufficient to fully stimulate the biological activity, or is 0.05, 0.1, 0.5, 1, 3 or 10 μg/ml. Preferably, at least 50%, 75%, 90%, or 95% or essentially complete inhibition isachieved when the molar ratio of antibody to cytokine is 0.5×, 1×, 2×, 3×, 5× or 10×. Preferably, the mAb is neutralizing, i.e., inhibit the biological activity, when used as a single agent, but in some methods, two mAbs are used together to give inhibition. Most preferably, the mAb neutralizes not just one but several of the biological activities listed above; for purposes herein, an anti-HGF mAb that used as a single agent neutralizes all the biological activities of HGF is called “fully neutralizing”, and such mAbs are most preferable. MAbs used in the invention are preferably be specific for HGF, that is they do not bind, or only bind to a much lesser extent, proteins that are related to HGF such as fibroblast growth factor (FGF) and vascular endothelial growth factor (VEGF). The mAbs typically have a binding affinity (Ka) of at least 10 7 M −1 but preferably 10 8 M −1 or higher, and most preferably 10 9 M −1 or higher or even 10 10 M −1 or higher.
[0024] MAbs used in the invention include antibodies in their natural tetrameric form (2 light chains and 2 heavy chains) and may be of any of the known isotypes IgG, IgA, IgM, IgD and IgE and their subtypes, i.e., human IgG1, IgG2, IgG3, IgG4 and mouse IgG1, IgG2a, IgG2b, and IgG3. The mAbs are also meant to include fragments of antibodies such as Fv, Fab and F(ab′)2; bifunctional hybrid antibodies (e.g., Lanzavecchia et al., Eur. J. Immunol. 17:105, 1987), single-chain antibodies (Huston et al., Proc. Natl. Acad. Sci. USA 85:5879, 1988; Bird et al., Science 242:423, 1988); and antibodies with altered constant regions (e.g., U.S. Pat. No. 5,624,821). The mAbs maybe of animal (e.g., mouse, rat, hamster or chicken) origin, or they may be genetically engineered. Rodent mAbs are made by standard methods well-known in the art, comprising multiple immunization with HGF in appropriate adjuvant i.p., i.v., or into the footpad, followed by extraction of spleen or lymph node cells and fusion with a suitable immortalized cell line, and then selection for hybridomas that produce antibody binding to HGF, e.g., see under Examples. Chimeric and humanized mAbs, made by art-known methods mentioned supra, are used in preferred embodiments of the invention. Human antibodies made, e.g., by phage display or transgenic mice methods are also preferred (see e.g., Dower et al., McCafferty et al., Winter, Lonberg et al., Kucherlapati, supra). More generally, human-like, reduced immunogenicity and genetically engineered antibodies as defined herein are all preferred.
[0025] The neutralizing anti-HGF mAb L2G7 (deposited at the American Type Culture Collection under ATCC Number PTA-5162 according to the Budapest treaty) is a preferred example of a Mab for use in the invention. The deposit will be maintained at an authorized depository and replaced in the event of mutation, nonviability or destruction for a period of at least five years after the most recent request for release of a sample was received by the depository, for a period of at least thirty years after the date of the deposit, or during the enforceable life of the related patent, whichever period is longest. All restrictions on the availability to the public of these cell lines will be irrevocably removed upon the issuance of a patent from the application. Neutralizing mabs with the same or overlapping epitope as L2G7 provide other examples. Variants of L2G7 such as a chimeric or humanized form of L2G7 are especially preferred. A mAb that competes with L2G7 for binding to HGF and neutralizes HGF in in vitro or in vivo assays described herein is also preferred. Other variants of L2G7 such as mAbs that are 90%, 95% or 99% identical to L2G7 in variable region amino acid sequence (e.g., when aligned by the Kabat numbering system; Kabat et al., op. cit.), at least in the CDRs, and maintain its functional properties, or which differ from it by a small number of functionally inconsequential amino acid substitutions (e.g., conservative substitutions), deletions, or insertions may also be used in the invention. Other preferred mAbs include human-like, reduced-immunogenicity and genetically engineered mAbs as defined herein.
[0026] Any amino acid substitutions from exemplified immunoglobulins are preferably conservative amino acid substitutions. For purposes of classifying amino acids substitutions as conservative or nonconservative, amino acids may be grouped as follows: Group I (hydrophobic sidechains): met, ala, val, leu, ile; Group II (neutral hydrophilic side chains): cys, ser, thr; Group III (acidic side chains): asp, glu; Group IV (basic side chains): asn, gln, his, lys, arg; Group V (residues influencing chain orientation): gly, pro; and Group VI (aromatic side chains): trp, tyr, phe. Conservative substitutions involve substitutions between amino acids in the same class. Non-conservative substitutions constitute exchanging a member of one of these classes for a member of another.
[0027] Yet other mAbs preferred for use in the invention include all the anti-HGF mAbs described in US 2005/0019327 A1 or WO 2005/017107 A2, whether explicitly by name or sequence or implicitly by description or relation to explicitly described mAbs (both cited applications are herein incorporated by reference for their disclosure of antibodies and all other purposes). Especially preferred mAbs are those produced by the hybridomas designated therein as 1.24.1, 1.29.1, 1.60.1, 1.61.3, 1.74.3, 1.75.1, 2.4.4, 2.12.1, 2.40.1 and 3.10.1 and respectively defined by their heavy and light chain variable region sequences provided by SEQ ID NO's 24-43 of WO2005/017107 A2; mAbs possessing the same respective CDRs as any of these listed mabs; mAbs having light and heavy chain variable regions that are at least 90%, 95% or 99% identical to the respective variable regions of these listed mAbs or differing from them only by inconsequential amino acid substitutions, deletion or insertions; mAbs binding to the same epitope of HGF as any of these listed mAbs, and all mAbs encompassed by claims 1 through 94 therein. Sequence identities are determined between immunoglobulin variable region sequences aligned using the Kabat numbering convention.
[0028] In other embodiments, a mAb for use in the invention, i.e., for treatment of a brain tumor by systemic administration of the mAb, binds to one or more of the following growth factors: vascular endothelial cell growth factor (VEGF); a neurotrophin such as nerve growth factor (NGF), brain-derived neurotrophic factor (BDNF), or NT-3; a transforming growth factor such as TGF-alpha or TGF-beta (TGF-β1 and/or TGF-β2); platelet-derived growth factor (PDGF); epidermal growth factor (EGF); heregulin; epiregulin; emphiregulin; a neuregulin (NRG-1α and/or NRG-1β, NRG-2α and/or NRG-2β, NRG-3, or NRG-4), insulin-like growth factor (IGF-1 and IGF-2); or in a preferred embodiment a fibroblast growth factor (FGF) especially acidic FGF (FGF-1) or most preferably basic FGF (FGF-2), but alternatively FGF-n, where n is any number from 3 to 23. In general, such a mAb is neutralizing. In still other embodiments, the mAb for use in the invention binds to a cellular receptor for any one or more of the above-mentioned growth factors.
[0029] Native mAbs for use in the invention may be produced from their hybridomas. Genetically engineered mAbs, e.g., chimeric or humanized mAbs, may be expressed by a variety of art-known methods. For example, genes encoding their light and heavy chain V regions may be synthesized from overlapping oligonucleotides and inserted together with available C regions into expression vectors (e.g., commercially available from Invitrogen) that provide the necessary regulatory regions, e.g., promoters, enhancers, poly A sites, etc. Use of the CMV promoter-enhancer is preferred. The expression vectors may then be transfected using various well-known methods such as lipofection or electroporation into a variety of mammalian cell lines such as CHO or non-producing myelomas including Sp2/0 and NSO, and cells expressing the antibodies selected by appropriate antibiotic selection. See, e.g., U.S. Pat. No. 5,530,101. Larger amounts of antibody may be produced by growing the cells in commercially available bioreactors.
[0030] Once expressed, the mAbs or other antibodies for use in the invention may be purified according to standard procedures of the art such as microfiltration, ultrafiltration, protein A or G affinity chromatography, size exclusion chromatography, anion exchange chromatography, cation exchange chromatography and/or other forms of affinity chromatography based on organic dyes or the like. Substantially pure antibodies of at least about 90 or 95% homogeneity are preferred, and 98% or 99% or more homogeneity most preferred, for pharmaceutical uses.
[0000] 3. Therapeutic Methods
[0031] In a preferred embodiment, the present invention provides a method of treatment with a pharmaceutical formulation comprising a mAb described herein. Pharmaceutical formulations of the antibodies contain the mAb in a physiologically acceptable carrier, optionally with excipients or stabilizers, in the form of lyophilized or aqueous solutions. Acceptable carriers, excipients or stabilizers are nontoxic to recipients at the dosages and concentrations employed, and include buffers such as phosphate, citrate, or acetate at a pH typically of 5.0 to 8.0, most often 6.0 to 7.0; salts such as sodium chloride, potassium chloride, etc. to make isotonic; antioxidants, preservatives, low molecular weight polypeptides, proteins, hydrophilic polymers such as polysorbate 80, amino acids, carbohydrates, chelating agents, sugars, and other standard ingredients known to those skilled in the art (Remington's Pharmaceutical Science 16th edition, Osol, A. Ed. 1980). The mAb is typically present at a concentration of 1-100 mg/ml, e.g., 10 mg/ml. The mAb can also be encapsulated into carrying agents such as liposomes.
[0032] In another preferred embodiment, the invention provides a method of treating a patient with a brain tumor by systemic administration of a mAb, such as a neutralizing anti-HGF mAb or an antibody against a cytokine or its receptor. The patient is preferably human but may be any mammal. By systemic administration, we mean herein a route of administration in which the mAb has general access to the circulatory system, and therefore to the organs of the body, including the blood vessels of the brain. In other words, the mAb is administered on the peripheral side of the blood brain barrier. Examples of systemic administration include intravenous infusion or bolus injection, or intramuscularly or subcutaneously or intraperitoneally. However, systemic administration does not encompass injection directly into the tumor or into an organ such as the brain or its surrounding membranes or cerebrospinal fluid. Intravenous infusion can be given over as little as 15 minutes, but more often for 30 minutes, or over 1, 2, 3 or even 4 or more hours. The dose given is sufficient to cure, at least partially alleviate or inhibit further development of the condition being treated (“therapeutically effective dose”). A therapeutically effective dose preferably causes regression or more preferably elimination of the tumor. A therapeutically effective dosage is usually from 0.1 to 5 mg/kg body weight, for example 1, 2, 3 or 4 mg/kg, but may be as high as 10 mg/kg or even 15 or 20 mg/kg. A fixed unit dose may also be given, for example, 50, 100, 200, 500 or 1000 mg, or the dose may be based on the patient's surface area, e.g., 100 mg/M 2 . A therapeutically effective dosage administered at a frequency sufficient to cure, at least partially alleviate or inhibit further development of the condition being treated is referred to as a therapeutically effective regime. Such a regime preferably causes regression or more preferably elimination of the tumor. Usually between 1 and 8 doses, (e.g., 1, 2, 3, 4, 5, 6, 7 or 8) are administered to treat cancer, but 10, 20 or more doses may be given. The mAb can be administered daily, biweekly, weekly, every other week, monthly or at some other interval, depending, e.g. on the half-life of the mAb, for 1 week, 2 weeks, 4 weeks, 8 weeks, 3-6 months or longer. Repeated courses of treatment are also possible, as is chronic administration.
[0033] The methods of this invention, e.g., systemic administration of a mAb such as anti-HGF mAb, especially L2G7 and its variants including humanized L2G7 , can be used to treat all brain tumors including meningiomas; gliomas including ependymomas, oligodendrogliomas, and all types of astrcytomas (low grade, anaplastic, and glioblastoma multiforme or simply glioblastoma); medullablastomas, gangliogliomas, schwannomas, chordomas; and brain tumors primarily of children including primitive neuroectodermal tumors. Both primary brain tumors (i.e., arising in the brain) and secondary or metastatic brain tumors can be treated by the methods of the invention. Brain tumors that express Met and/or HGF, especially at elevated levels, are particularly suitable for treatment by systemic administration of a neutralizing anti-HGF antibody such as L2G7 or its variants.
[0034] In a preferred embodiment, the mAb is administered together in combination with (i.e., before, during or after) other anti-cancer therapy. For example, the mAb, e.g., an anti-HGF mAb such as L2G7 and its variants, may be administered together with any one or more of the chemotherapeutic drugs known to those of skill in the art of oncology, for example alkylating agents such as carmustine, chlorambucil, cisplatin, carboplatin, oxiplatin, procarbazine, and cyclophosphamide; antimetabolites such as fluorouracil, floxuridine, fludarabine, gemcitabine, methotrexate and hydroxyurea; natural products including plant alkaloids and antibiotics such as bleomycin, doxorubicin, daunorubicin, idarubicin, etoposide, mitomycin, mitoxantrone, vinblastine, vincristine, and Taxol (paclitaxel) or related compounds such as Taxotere®; agents specifically approved for brain tumors including temozolomide and Gliadel® wafer containing carmustine; and other drugs including irinotecan and Gleevec® and all approved and experimental anti-cancer agents listed in WO 2005/017107 A2 (which is herein incorporated by reference). The mAb can be administered in combination with 1, 2, 3 or more of these agents, e.g., in a standard chemotherapeutic regimen. Other agents with which an anti-HGF mAb can be administered include biologics such as monoclonal antibodies, including Herceptin™ against the HER2 antigen, Avastin™ against VEGF, antibodies to the EGF receptor such as Erbitux®, or an anti-FGF mAb, as well as small molecule anti-angiogenic or EGF receptor antagonist drugs such as Iressa® and Tarceva®. In addition, the mAb can be administered together with any form of radiation therapy including external beam radiation, intensity modulated radiation therapy (IMRT) and any form of radiosurgery including Gamma Knife, Cyberknife, Linac, and interstitial radiation (e.g. implanted radioactive seeds, GliaSite balloon).
[0035] Although in a preferred embodiment of the invention, the mAb is not linked or conjugated to any other agent, in other embodiments the mAb may be conjugated to a radioisotope, chemotherapeutic drug or prodrug or a toxin. For example, it may be linked to a radioisotope that emits alpha, beta and/or gamma rays, e.g., 90Y, isotopes of iodine such as 131I, or isotopes of bismuth such as 212Bi or 214Bi; to a plant or bacterial protein toxin such as ricin or pseudomonas exotoxin or their fragments such as PE40; to a small-molecule toxin such as compounds related to or derived from calicheamicin, auristatin or maytansine; or to a chemotherapeutic drug such as doxorubin or any of the others chemotherapeutic drugs listed above. Methods of linking such agents to a mAb are well-known to those skilled in the art.
[0036] Systemic administration of a mAb, e.g., a neutralizing anti-HGF mAb such as L2G7 or its variants, optionally plus other treatment (e.g., chemotherapy or radiation therapy), can increase the median progression-free survival or overall survival time of patients with certain brain tumors (e.g., glioblastomas) by at least 30% or 40% but preferably 50%, 60% to 70% or even 100% or longer, compared to a control regime without administration of the mAb. If administration of anti-HGF mAb is accompanied by other treatment such as chemotherapy or radiation, the other treatment is also included in the control regime. If anti-HGF mAb is administered without other treatment, the control regime is a placebo or no specific treatment. In addition or alternatively, systemic administration of a mAb, e.g., a neutralizing anti-HGF mAb such as L2G7 or its variants, plus other treatment (e.g., chemotherapy or radiation therapy), may increase the complete response rate (complete regression of the tumor, i.e., remission), partial response rate (a partial response in a patient means partial shrinkage of the tumor size, e.g., by at least 30% or 50%), or objective response rate (complete+partial) of patients with certain brain tumors by at least 30% or 40% of the patients but preferably 50%, 60% to 70% or even 90% or more compared to a control regime without administration of the mAb as described above. Changes in the size of a tumor responsive to treatment can be determined by MRI, CT scanning and the like.
[0037] Similarly, when systemically administered to animals (e.g., immunodeficient mice such as nude mice or SCID mice) bearing intracranial xenografts of human glioma tumors, e.g., as described in Example 2 below, the neutralizing anti-HGF mAb or anti-FGF mAb or other mAb will prolong median survival of the animals by at least about 25 or 30 or 40 days, but preferably 50, 60, or 70 days or even longer, and such an extension will be statistically significant. This will be true even when initiation of treatment is delayed until at least 5 or 18 days or longer after tumor cell implantation. Moreover, such treatment will on average shrink the tumors by at least 25% but preferably 50% or even 75%; and the average tumor volume in animals treated with the mAb will be less than 50% or even 25% or 10% of the average tumor volume in control-treated animals. The tumor size will typically be measured 21 or 29 days after tumor cell implantation.
[0038] Typically, in a clinical trial (e.g., a phase II, phase II/III or phase III trial), the aforementioned increases in median progression-free survival and/or response rate of the patients treated by administration of a mAb, e.g., an anti-HGF mAb, optionally plus other treatment relative to the patients receiving a control regime without the antibody, are statistically significant, for example at the p=0.05 or 0.01 or even 0.001 level. The complete and partial response rates are determined by objective criteria commonly used in clinical trials for cancer, e.g., as listed or accepted by the National Cancer Institute and/or Food and Drug Administration.
EXAMPLES
[0000] 1. Generation and In Vitro Properties of Anti-HGF mAbs
[0039] The development of a fully neutralizing anti-HGF mAb L2G7 has been described in U.S. Patent Application Pub. No. US 2005/0019327 A1, which is herein incorporated by reference. In summary, Balb/c mice were extensively immunized with recombinant human HGF by footpad injections, and hybridomas were generated from them by conventional means. Chimeric fusion proteins consisting of HGF fused to Flag peptide (HGF-Flag), and the Met extracellular domain fused to the human IgG1 Fc region (Met-Fc), were produced by conventional recombinant techniques and used to determine the ability of the anti-HGF mAbs to inhibit the binding of HGF to its Met receptor. FIG. 1 a demonstrates the ability of three separate anti-HGF mAbs, each recognizing a different epitope to capture HGF in solution. Although the IgG2a mAb L2G7 has intermediate affinity for HGF as judged by binding ability, it is the only mAb identified that completely blocks binding of HGF-Flag to Met-Fc in an ELISA ( FIG. 1 b ). The mAb L2G7 is specific for HGF, as it shows no binding to other growth factors such as VEGF, FGF or EGF.
[0040] The ability of mAb L2G7 to block HGF binding to Met suggested that it would inhibit all HGF-induced cell responses, but this supposition required verification because the α and β-subunits of HGF mediate different activities (Lokker et al., EMBO J. 11: 2503, 1992; Hartmann et al., Proc. Natl Acad. Sci. USA 89: 11574, 1992). One important bioactivity of HGF mediated through its α-subunit, from which its alternate name “scatter factor” derives, is the ability to induce cell scattering. FIG. 2 a shows that L2G7 is able to completely inhibit HGF-induced scattering of MDCK epithelial cells, a widely used biological assay for quantifying HGF scatter activity. A key biological activity of HGF mediated through its β subunit is mitogenesis of certain cell types. FIG. 2 b shows that L2G7 at a 1:1 molar ratio of mAb to HGF completely inhibits HGF-induced 3H-thymidine incorporation in Mv 1 Lu mink lung epithelial cells. Thus, mAb L2G7 blocks HGF-induced biological activities attributable to both the α- and β-HGF subunits.
[0041] Angiogenesis is required for growth of solid tumors. HGF is a potent angiogenic factor (Grant et al., Proc. Natl Acad. Sci. USA 90: 1937, 1993) and tumor levels of HGF correlate with the vascular density of human malignancies including gliomas (Schmidt. et al. Int. J. Cancer 84: 10, 1999). HGF can also stimulate the production of other angiogenic factors such as VEGF and can potentiate VEGF-induced angiogenesis (Xin et al. Am. J. Pathol. 158, 1111, 2001). Two early steps involved in angiogenesis are endothelial cell proliferation and tubule formation. The effect of L2G7 on HGF-induced proliferation of human umbilical vein endothelial cells (HUVEC) and formation of vessel-like tubules in 3 dimensional collagen gels was therefore determined. Stimulation of HUVEC proliferation by HGF (50 ng/ml, 72 hr) was completely inhibited by L2G7 at a 1.5:1 mAb to HGF molar ratio ( FIG. 2 c ). HUVECs suspended in 3-D collagen gels developed an interconnected branching tubule network after stimulation with HGF (200 ng/ml, 48 hr), while cells treated with HGF plus L2G7 showed little or no such tubule formation ( FIG. 2 d ). Hence L2G7 blocks HGF-induced proliferative and morphogenic aspects of angiogenesis.
[0042] HGF protects tumor cells from apoptotic death induced by numerous modalities including DNA-damaging agents commonly used in cancer therapy (Bowers et al. Cancer Res. 60: 4277, 2000; Fan et al. Oncogene 24: 1749, 2005). The majority of human malignant glioma cells express the death receptor FAS, making them susceptible to apoptosis induced by anti-FAS antibody in vitro (Weller et al. J. Clin. Invest. 94: 954, 1994). Thus, the effects of L2G7 on HGF-mediated cytoprotection of U87 glioma cells treated with apoptotic anti-FAS mAb CH-11 were determined. U87 cell viability after CH-11 treatment (24 hr) was reduced to ˜45% of that in untreated controls, an effect that was completely reversed by pre-incubating cells with HGF in the presence of an irrelevant isotype control antibody but not by HGF in the presence of L2G7 ( FIG. 2 e ).
[0000] 2. Effects of Anti-HGF mAb in Glioma Xenograft Tumor Models
[0043] The ability of L2G7 to block multiple tumor-promoting activities of HGF suggested this mAb would have anti-tumor activity against at least HGF+/Met+human tumors. The majority of gliomas appear to express Met and HGF (Rosen et al. Int. J. Cancer 67: 248, 1996). For the glioma cell lines U87 and U118, Met expression was confirmed by flow cytometric analysis, and ˜20-35 ng/ml HGF in supernatants from 7-day old confluent cultures using an HGF-specific ELISA was detected. The anti-tumor effect of L2G7 in nude mouse models of pre-established U118 and U87 subcutaneous xenografts was determined. L2G7 was administered i.p. twice weekly after tumor sizes had reached ˜50 mm 3 as described (Kim et al., Nature 362: 841, 1993, which is herein incorporated by reference). At 100 μg (˜5 mg/kg) per injection, L2G7 completely inhibited growth of U118 tumors ( FIG. 3 a ). In the U87 xenograft model, either 50 μg or 100 μg L2G7 per injection not only inhibited tumor growth but actually caused tumor regression ( FIG. 3 b ). Control mAb (100 μg per injection) only slightly inhibited tumor growth compared to PBS control. L2G7 had no effect on the growth of U251 glioma tumor xenografts, which express Met but do not secrete HGF. These in vivo results demonstrate that L2G7 as a single agent prevents tumor growth by specifically blocking HGF activity.
[0044] Next, L2G7 efficacy was examined in mice bearing pre-established intracranial U87 glioma xenografts. Mice were implanted with U87 human malignant glioma cells (100,000 cells/animal) by stereotactic injection to the right caudate/putamen. L2G7 (100 μg/injection, i.p., twice weekly) administered from post-implantation day 5 though day 52 significantly prolonged animal survival ( FIG. 3 c ). In control mice, median survival was 39 days and all mice died from progressive tumors by day 41. In contrast, all mice treated with L2G7 survived through day 70, and 80% survived through day 90, seven weeks after cessation of mAb treatment ( FIG. 3 c ). In sacrificed mice, on day 21 after three doses of L2G7 , control tumors were more than 10-fold larger than L2G7 -treated tumors (6.6+2.7 mm3 vs. 0.54+0.17 mm3) ( FIG. 3 d ).
[0045] To test the mAb efficacy under even more stringent conditions, in a similar experiment initiation of L2G7 treatment was delayed until day 18. A subset of mice (n=5 per group) was sacrificed early in the course of treatment, and tumor volumes were quantified by measuring tumor cross-sectional areas of H&E stained brain sections using computer assisted image analysis. L2G7 induced substantial tumor regression ( FIG. 3 e, f ). Specifically, pre-treatment tumor volumes on day 18 were 26.7+2.5 mm3 (range 19.5-54 mm3, median 27.9 mm3). On day 29, after 3 doses of L2G7 , tumors were only 11.7+5.0 mm3 (range 0-26.2 mm3 median 7.5 mm3), so the tumors had actually regressed or shunk in size on average by 50% or more. Tumor volumes on day 29 from mice treated with isotype-matched control mAb were 134.3+22.0 mm3 (range 71.2-196.8 mm3, median 128 mm 3 ). Hence, tumors treated with control mAb grew nearly 5 fold with a mean volume 12 times larger than the L2G7 -treated tumors. In the mice that were not sacrificed (n=10 per group), median survival in the control mice was 32 days and all died by day 42, while none of the L2G7 -treated mice died until day 46, and L2G7 extended median survival to day 61. Thus, L2G7 induced tumor regression in mice with very high tumor burdens.
[0046] A more detailed analysis of histological sections of intracranial tumors was performed to investigate potential mechanisms of the anti-tumor effects of L2G7 ( FIG. 4 ). Following three doses of L2G7 , tumor cell proliferation (Ki-67 index) and angiogenesis (vessel density, i.e. area of anti-laminin stained tumor vessels as percent of tumor area) were reduced by 51% and 62% respectively, while the apoptotic index of tumor cells quantified by the number of activated caspase-3 positive cells was increased 6-fold. The pronounced tumor regression that occurred soon after initiating L2G7 therapy is indicative of a cell death response similar to that observed in human colon tumor Colo 205 xenografts treated with an agonist anti-death receptor 4 (TRAIL1) mAb (Chuntharapai et al. J. Immunol. 166: 4891, 2001).
[0047] The results reported here are a striking example of brain tumor responses from a mAb not linked to a toxin or radionuclide. As a comparison, in subcutaneous xenograft models the anti-VEGF murine mAb A4.6.1, which was later humanized to create the drug Avastin®, inhibited growth of the G55 human glioma by only ˜50-60% (Kim et al., Nature 362: 841, 1993), contrasted with essentially complete growth inhibition of the U87 and U118 gliomas by mAb L2G7. In an orthotopic intracranial tumor model, systemic anti-VEGF mAb administered simultaneously with G55 glioma cell implantation prolonged animal survival by only 2-3 weeks (Rubenstein et al. Neoplasia 2: 306, 2000). Similarly, systemic administration of a mAb to a variant of the EGF receptor prolonged median survival of mice with intracranial xenografts of glioma cells transfected with the variant EGF receptor, in general modestly (from 13 to 21 days or from 13 to 19 days, but in one case from 19 days to 58 days; Mishima et al., Cancer Res. 61: 4349, 2001). However, these modest effects were achieved when mAb administration began simultaneously with or shortly after xenograft implantation and hence were likely caused, at least in part, by delaying the initiation of xenograft vascularization, an event that cannot be targeted in patients with pre-existing brain tumors. In contrast, systemic administration of anti-HGF mAb L2G7 prolonged survival and caused tumor regression even when administered on Day 5 or even Day 18 after implantation when the tumors were well-established, and thus corresponds to the situation in human patients.
[0048] The pronounced anti-tumor effects of mAb L2G7 are likely due to the unique multifunctional properties of its molecular target HGF, i.e., mitogenic, angiogenic, and cytoprotective (Birchmeier et al. Nat. Rev. Mol. Cell Biol. 4: 915, 2003; Trusolino et al. Nat. Rev. Cancer 4: 289, 2002). The ability of L2G7 to induce glioma regression implicates a cell death response that could result from Fas-mediated apoptosis, which is blocked by HGF binding to Met (Wang et al. Cell. 9: 411, 2002) or from inactivating HGF-induced cytoprotective pathways that involve phosphatidyl inositol 3-kinase, Akt, and NF-kappaB intermediates (Fan et al. Oncogene 24: 1749, 2005). The ability of L2G7 to block the cytoprotective and angiogenic effects of HGF predicts that L2G7 delivered systemically potentiates cytotoxic modalities such as γ-radiation and chemotherapy currently used to treat malignant brain tumors.
[0049] Although the invention has been described with reference to the presently preferred embodiments, it should be understood that various modifications can be made without departing from the invention.
[0050] All publications, patents and patent applications cited are herein incorporated by reference in their entirety for all purposes to the same extent as if each individual publication, patent and patent application was specifically and individually indicated to be incorporated by reference in its entirety for all purposes. | The application is directed toward a method of treating a brain tumor in a patient comprising systemically administering a monoclonal antibody. | 2 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority to PCT Application No. PCT/EP2015/077065, having a filing date of Nov. 19, 2015, based off of German application No. 1020152004 20.1 having a filing date of Jan. 14, 2015, the entire contents both of which are hereby incorporated by reference.
FIELD OF TECHNOLOGY
[0002] The following relates to a method and a system for populating printed circuit boards. To this end, a pick-and-place line is provided, which is designed to populate printed circuit boards with components.
BACKGROUND
[0003] An electronic module comprises a printed circuit board and components which are mechanically and electrically attached thereto. To produce the printed circuit board, components are arranged on the printed circuit board using an automatic pick-and-place unit, and thereafter soldered thereto in a reflow oven. A plurality of automatic pick-and-place units can be arranged sequentially on a pick-and-place line. For the production of multiple printed circuit boards, a pick-and-place system can be employed, comprising a plurality of pick-and-place lines.
[0004] A combination of component types on the automatic pick-and-place unit is described as a set-up. Using a set-up, a quantity of different printed circuit boards can be produced, which are described as a set-up family. Customarily, however, printed circuit boards of more different printed circuit board types are to be produced than is possible using a single set-up, thereby necessitating a change of set-up in the course of production.
[0005] A set-up can be accommodated on one or more set-up tables, which can easily be replaced on the automatic pick-and-place unit. However, the equipment of a set-up table with components of predefined component types is complex. Consequently, a distinction is frequently drawn between fixed set-ups and variant set-ups, wherein a fixed set-up table is intended to retain its composition of component types over a predefined planning period, whereas a variant set-up table will foreseeably be refitted within said planning period.
[0006] DE 10 2012 220 904 A1 relates to a method for determining a most advantageous fixed set-up possible for a pick-and-place line.
SUMMARY
[0007] An aspect relates to an improved method, a computer program product and a system for populating printed circuit boards which permit a more efficient population of a pick-and-place line.
[0008] For populating printed circuit boards by a pick-and-place line, set-up families having associated set-ups are provided. Each set-up family is assigned at least one printed circuit board type, and each set-up is assigned at least one component type, such that a printed circuit board of a printed circuit board type of a set-up family can be populated by components of the component types of the set-up assigned to the printed circuit board type on the pick-and-place line. A set-up can be implemented in the form of supplies of components of the component types, in order to be fitted on the pick-and-place line. A method for populating printed circuit boards comprises steps of acquiring jobs, in each case relating to the population of printed circuit boards of a printed circuit board type on the pick-and-place line, and associated probabilities with which a job is to be executed in each case, assigning printed circuit board types of the jobs to set-up families, determining, for each set-up family, a characteristic number which comprises the sum of probabilities of those jobs, the printed circuit board types of which are comprised by the set-up family, optimizing the assignment in such a way that the characteristic numbers of different set-up families are as different as possible, providing a set-up from one of the determined set-up families on the pick-and-place line, and populating printed circuit boards on the pick-and-place line.
[0009] Jobs can be associated with practically any time period in the future. Customarily, it is not known—or not exactly known—when a job is actually on hand, and thus when the job is to be executed. The operation of the pick-and-place line customarily follows a predefined rotation wherein, for a given forthcoming period, it is known in each case which jobs are to be processed. The probability of the job indicates how probable it is that a job will need to be executed within any given time period.
[0010] By means of the method, set-ups or set-up families can be constituted in consideration of the knowledge that the population of specific printed circuit board types will recur on a regular basis. The determination of set-ups can thus be improved, such that the change of set-ups during production is reduced. The number of set-ups to be produced can thus be reduced. Preferably, by the method, fixed set-ups are defined which, within a long-term planning period, for example of several days or weeks, are to be fitted to the pick-and-place line in a repeated manner. Jobs which, at the time of execution of the method, are not known, can be processed by variant set-ups, which are only equipped on a one-off basis, then employed on the pick-and-place line on a one-off basis and removed again thereafter. Of the present jobs, not all will need to be considered in the determination of fixed set-ups, as described hereinafter—specifically, jobs with the lowest probabilities can also be ignored in the constitution of fixed set-ups.
[0011] Preferably, optimization is executed such that the number of set-up families is minimized. A number of set-ups can also be reduced accordingly, thereby generating advantages with respect to handling and costs.
[0012] The method can be executed with respect to a predefined time period, wherein the processing time for a job does not exceed said time period. Specifically, the probabilities can relate to the occurrence of a job within the respective time period. This time period is also described as the short-term planning horizon and can, for example, be one day. In other words, it is preferably assumed that each job can be completely processed before the time period has expired. Customarily, predefined jobs to be processed are specified for each time period.
[0013] Probabilities can be determined with reference to previous jobs. For example, experiences obtained from previous production periods can be advantageously employed. Specifically, frequencies of previous jobs can be known, and probabilities determined therefrom. Alternatively or additionally, knowledge of forthcoming jobs can also be employed. In an actual production operation, for example, jobs can be defined for a specific rotation.
[0014] In a first variant, the set-up families are constituted individually in sequence, wherein optimization is executed in each case such that a number of jobs which can be processed using set-ups from the set-up families is maximized.
[0015] In a second variant, the set-up families are constituted individually in sequence, and optimization is executed in each case such that, for the printed circuit board types assigned to a new set-up family, the following characteristic number is minimized:
[0000] log(1−p r ); where p r is the probability of an occurrence of a job for the population of printed circuit boards of printed circuit board type r. The probability customarily relates to the predefined time period, i.e. the short-term planning horizon.
[0016] Optimization is preferably executed by mixed integer optimization. Effective optimization can thus be achieved in a relatively short processing time; the discrepancy (gap) of optimization from a best possible solution can also be defined.
[0017] A computer program product comprises programming code means or programming code for executing a method, where said computer program product is run on a processing device or is stored on a computer-readable data medium.
[0018] A control unit is designed for acquiring jobs, in each case relating to the population of printed circuit boards of a printed circuit board type on the pick-and-place line, and associated probabilities with which a job is to be executed in each case, assigning printed circuit board types of the jobs to set-up families, determining, for each set-up family, a characteristic number which comprises the sum of probabilities of those jobs, the printed circuit board types of which are comprised by the set-up family, optimizing the assignment in such a way that the characteristic numbers of different set-up families are as different as possible, and controlling the population of printed circuit boards on the pick-and-place line, where a set-up from one of the determined set-up families is fitted on the pick-and-place line.
BRIEF DESCRIPTION
[0019] Some of the embodiments will be described in detail, with references to the following figures, wherein like designations denote like members, wherein:
[0020] FIG. 1 shows a pick-and-place system, in accordance with embodiments of the present invention;
[0021] FIG. 2 shows a representation of set-up families on a pick-and-place line according to FIG. 1 ;
[0022] FIGS. 3-5 show job numbers for various set-up families in different examples; and
[0023] FIG. 6 shows a flow chart of a method for the constitution of fixed set-ups for a pick-and-place system according to FIG. 1 .
DETAILED DESCRIPTION
[0024] FIG. 1 shows an exemplary pick-and-place system 100 . The pick-and-place system 100 comprises one or more pick-and-place lines 110 and a processing or control unit 115 . Each pick-and-place line 110 comprises an optional conveyor system 125 and one or more automatic pick-and-place units 130 . Each automatic pick-and-place unit 130 comprises one or more pick-and-place heads 135 , each of which is designed for the pick-up of components 155 from a set-up table 140 and the placement thereof at a predefined position on the printed circuit board 120 , which is located on the conveyor system 125 . During the population process, the printed circuit board 120 is customarily stationary, in relation to the automatic pick-and-place unit 130 .
[0025] The set-up tables 140 each comprise a plurality of infeed devices 150 of which, in FIG. 1 , only one is represented for exemplary purposes. Each infeed device 150 holds a stock of components 155 of a predefined component type 160 . For the components 155 , the infeed device 150 customarily has a holding capacity, which can be expressed in terms of tracks. A track is customarily 8 mm wide, and the number of tracks on a set-up table 140 is limited, for example to 40. Components 155 of the same component type 160 are customarily delivered in the form of a belt, on a tablet or in a tube. Each component type 160 requires a predefined number of tracks on the infeed device 150 and on the set-up table 140 , which are customarily mutually adjoining.
[0026] Generally, an infeed device 150 can be configured for the accommodation of components 155 of different component types 160 and, customarily, different infeed devices 150 can be fitted to a set-up table 140 . In the present case, in the interests of simplification, it is assumed that a stock of components 155 of a component type 160 on an infeed device 150 is practically inexhaustible, such that restocking is not required.
[0027] If, on the automatic pick-and-place unit 130 , a component 155 of a component type 160 is required which is not present on one of the set-up tables 140 , customarily, the assignment of components 155 on one of the set-up tables 140 fitted is not altered, but the set-up table 140 is completely replaced with another and appropriately-populated set-up table 140 . The population of a set-up table 140 , which is not fitted to the pick-and-place line 110 , with components 155 is described as prefitting, and can require a processing time of the order of one or more hours, for example approximately 6-10 hours.
[0028] As a change of set-up tables 140 on the pick-and-place line 110 , or so-called set-up change, is customarily associated with an interruption in production, it is endeavored to change the set-up tables 140 as infrequently as possible. Given that, moreover, the set-up tables 140 are expensive, and the changeover of a set-up table 140 can be a complex and lengthy operation, it is moreover endeavored to constitute the smallest possible number of set-ups, in order to manufacture a predefined production volume of printed circuit boards 120 of predefined printed circuit board types 122 . In this case, the production volume comprises a plurality of printed circuit board types 122 , of which in each case a predetermined batch quantity of printed circuit boards 120 is to be populated with components 155 of predefined component types 160 . For example, 300 printed circuit boards 120 of a first printed circuit board type 122 , and 200 printed circuit boards 120 of a second circuit board type 122 , can be populated.
[0029] A set-up 165 , 170 comprises a quantity of component types 160 , and is comprised of one or more set-up tables 140 , which are equipped with stocks of components 155 of the component types 160 of the set-up 165 , 170 , and are fitted to the pick-and-place line 110 .
[0030] A set-up family 175 is assigned to the set-up 165 , 170 , which comprises printed circuit board types 122 , from which printed circuit boards 120 can be populated by components 155 of the component types 160 from the set-up 165 , 170 . A set-up family 175 is specifically assigned to a set-up 165 , 170 and vice versa.
[0031] In order to increase capacity utilization on a pick-and-place line 110 , or to reduce a requirement for set-up tables 140 , the constitution of set-up families 175 on the basis of the printed circuit board types 122 to be populated is therefore critical. The constitution of set-ups 165 , 170 or set-up families 175 can involve the consideration of ancillary conditions, such as compliance with a limited holding capacity of a set-up table 140 for component types 160 or a grouping of predefined printed circuit board types 160 in the same set-up family 175 , for example on the grounds of the use of lead-based or lead-free solder.
[0032] Set-ups can be divided into fixed set-ups 165 and variant set-ups 170 , wherein the fitting of a fixed set-up 165 is intended to remain unchanged on a number of shuttle tables 140 over a predefined planning period, whereas a shuttle table 140 of a variant set-up 170 will foreseeably be refitted with components 155 of different component types 160 within the planning period. The planning period can be, for example, 6-12 months. A variant set-up 165 is customarily present in a predefined configuration for a substantially shorter time than the planning period, for example a number of hours or days, but customarily not more than one week.
[0033] A static set-up can also be constituted, which includes elements of the fixed set-up 165 and the variant set-up 170 . The static set-up, in the same way as the fixed set-up 165 , is constituted for a longer period, during which it customarily remains unchanged. However, a static set-up does not customarily remain fitted, i.e. constituted as a physical set-up on set-up tables 140 , but can also be removed after use. Moreover, a static set-up can also be fitted (i.e. completed) on a partial basis only if, for example, the static set-up comprises a plurality of printed circuit board types 122 and, at a given time point, only jobs for the production of printed circuit boards 120 of some of these printed circuit board types 122 are on hand. In this case, components 155 of such component types 160 which are not required for the population of the printed circuit boards 120 ordered do not need to be fitted.
[0034] Administratively, the static set-up is substantially easier to manage than a fixed set-up 165 or a variant set-up 170 . If the static set-up, further to the use thereof, is not set down, it can also be described as a fixed set-up 165 . Hereinafter, unless indicated otherwise, reference is preferably intended to static set-up families and the static set-ups assigned thereto.
[0035] Set-ups 165 , 170 can be replaced, as required, on the pick-and-place line 110 . In order to constitute a fixed set-up 165 or a variant set-up 170 , a set-up table 140 , while not fitted to the pick-and-place line 110 , can be equipped with stocks of components 155 of predefined component types 160 . Previously fitted components 155 of component types 160 which are not required can be removed beforehand. This refit can involve a substantial amount of manual labor, and can be time-intensive.
[0036] In order to minimize the complexity associated with a variant set-up 170 , it is endeavored that fixed set-ups 165 should accommodate as many printed circuit board types 122 as possible. In practice, however, a target case involving no variant set-ups 170 is scarcely achievable.
[0037] The control device 115 , in the context of the control of the pick-and-place system 100 , assigns printed circuit board types 122 , the associated printed circuit boards 120 whereof are to be populated on the pick-and-place line 110 , to one set-up family 175 respectively, wherein fixed set-up families 175 , which are assigned respectively to a fixed set-up 165 , and variant set-up families 175 , which are assigned respectively to a variant set-up 170 , can be constituted.
[0038] In practice, for example, for a given production quantity of printed circuit board types 122 , in a first step, a fixed set-up 165 is constituted for a (largest possible) proportion of printed circuit board types 122 , whereafter, in a second step, variant set-ups 170 are constituted for the remaining proportion of printed circuit board types 122 . The quality of these assignment operations dictates, to a substantial degree, the extent of effective capacity utilization of production means of the pick-and-place system 100 , and how efficiently population is executed.
[0039] FIG. 2 shows a representation of exemplary set-up families 175 on a pick-and-place line 110 according to FIG. 1 . In this case, the set-up families 175 are divided into a fixed set-up family 210 , which is assigned to a fixed set-up 165 , and a variant set-up family 215 , which is assigned to a variant set-up 170 . In the example represented, within a planning period 205 , printed circuit board types 122 of a single fixed set-up family 210 or of a single variant set-up family 215 can be populated on the pick-and-place line 110 .
[0040] It is assumed that, at the start of the planning period 205 , a number of jobs 220 are on hand, which are to be executed as efficiently as possible. The number of jobs is described as the job number. Each job 220 comprises at least one printed circuit board type 122 and one batch quantity 225 of printed circuit boards 120 to be populated. Component types 160 are assigned to the printed circuit board type 122 , components 155 whereof are to be fitted to the individual printed circuit boards 120 .
[0041] Further information can be assigned to a printed circuit board type 122 . For example, a number 230 of component types 160 which are to be fitted to each printed circuit board 120 , a number 235 of population positions on a printed circuit board 120 , or a production time 240 for a printed circuit board 120 of the respective printed circuit board type 122 , can be indicated. The number of population positions corresponds to the number of components 155 which are to be fitted to a printed circuit board 120 of a printed circuit board type 122 , of whatever component type 160 . Moreover, a job number 245 can be indicated, which indicates how many jobs 220 for the population of printed circuit boards 120 of a printed circuit board type 122 are on hand within a predefined planning period 205 .
[0042] By the employment of mathematical methods, significantly superior solutions for the assignment of printed circuit board types 122 to fixed set-up families 175 or to pick-and-place lines 110 can be achieved than by the methods applied previously in practice. For the determination of an optimum assignment of printed circuit board types 122 to a fixed set-up family 175 , automatic optimization can be employed. To this end, different optimization methods can be applied, for example, on the basis of local search methods or metaheuristic algorithms.
[0043] Preferably, however, an IP model (integer programming or an integer program, or a mixed integer optimization model) is employed. One of the principal methods in the field of mathematical optimization is linear optimization, which involves the optimization of linear target functions in respect of a quantity which is restricted by linear equalities and inequalities. Linear optimization forms the basis of the procedural solution of (mixed) integer linear optimization.
[0044] Advantages of linear optimization are as follows:
A global optimization approach Easily extendable Commercial availability of very effective standard solvers (Ilog, Gurobi, Xpress), which are widespread and proven in practice, For any solution determined, the maximum discrepancy thereof (gap) from the optimum solution is known.
[0049] Hereinafter, examples of IP formulations are provided for the optimization of the described assignment of printed circuit board types 122 to a fixed set-up family 175 .
[0050] A short-term planning period T K is assumed, for example of several hours or days, and a long-term planning period T L , which is a number of times longer than T K , for example of several days, weeks or months. Fixed set-ups are defined for the pick-and-place line 110 , which are to remain unchanged over the long-term planning period T L , and can be employed a number of times. The definition should proceed such that, in the operation of the pick-and-place line 110 , as few set-up changeovers and as few set-ups as possible are required. To this end, the circumstance is exploited whereby, at the time of definition of fixed set-ups, some information on forthcoming jobs is already known.
[0051] In the operation of the pick-and-place line 110 , it is known which jobs are to be processed in the next respective short-term planning period. If a job cannot be processed using one of the fixed set-ups, a variant set-up must be prepared. The frequency of set-up changeovers, and the frequency of the necessity for the preparation of variant set-ups, is therefore critically dependent upon the quality of the aforementioned assignment of printed circuit board types to fixed set-up families.
[0052] Symbols
R is the quantity of printed circuit board types Cl is the quantity of set-up families, consisting of all the printed circuit board types from R Order r is the number of jobs for the printed circuit board type r in the long-term planning period T L is the number of days in the long-term planning period T K is the number of days in the short-term planning period
[0059] Evaluation Model
[0000] Order r <T L /T K applies. This condition can be fulfilled, where applicable, by a setting for Order r :=T L /T K .
p r is the probability of the execution of a job for the population of a printed circuit board 120 of a printed circuit board type 122 within the short-term planning period T K , for example 0.08. The probability p r corresponds to the average relative frequency at which such jobs occur, in the above case, for example, where 8 such jobs are to be executed in the course of 100 short-term planning periods T K . This frequency can be determined, for example, with reference to previous planning periods T K , or with reference to the knowledge of forthcoming jobs.
[0060] It is assumed that, in each case, jobs are distributed evenly over the short-term planning periods T K .
[0000]
p
r
=
T
K
Order
r
T
L
[0061] It is further assumed that the jobs are mutually independent. Within the short-term planning period T K , all jobs on hand can be processed by the fixed set-up and one or more variant set-ups. To this end, each variant set-up required in the short-term planning period T K is set up only once, all the printed circuit boards of the assigned printed circuit board types which are to be produced are populated, and the variant set-up is set down again thereafter. A further application of the variant set-up on the pick-and-place line 110 is not anticipated.
[0062] The expected value for the required set up of a set-up family clεCl on the pick-and-place line 110 within the short-term planning period is determined as follows:
[0000]
EW
(
cl
)
=
probability
that
at
least
one
module
r
∈
cl
must
be
produced
=
1
-
probability
that
no
module
r
∈
cl
must
be
produced
=
1
-
∏
r
∈
cl
(
1
-
p
r
)
[0063] An expected value “EW(Number)” for the number of set-up families to be set up within a short-term planning period is thus given by the following:
[0000]
EW
(
Number
)
=
∑
cl
∈
Cl
1
-
∏
r
∈
cl
(
1
-
p
r
)
=
Number
of
set
-
up
families
-
∑
cl
∈
Cl
∏
r
∈
cl
(
1
-
p
r
)
[0064] This expected value is an effective quality criterion for a quantity of fixed set-up families Cl.
Examples
[0065] In the following examples, the long-term planning period is 100 days and the short-term planning period is 1 day. It has been shown that, with respect to the order number, unbalanced fixed set-up families are tendentially superior to balanced fixed set-up families.
[0066] Modules and their associated job numbers are given by the following:
[0000]
Module
r1
r2
r3
r4
r5
r6
Number of jobs
90
70
50
50
30
10
pr
0.9
0.7
0.5
0.5
0.3
0.1
[0067] It is assumed that the set-ups, for example by means of the capacities of the set-up tables, are restricted in each case to the accommodation of components of component types for two printed circuit board types only, such that a set-up family can only accommodate two printed circuit board types.
[0068] FIG. 3 a represents balanced set-up families with respect to absolute job frequencies. A job number is plotted on the vertical axis, while different set-up families are represented on the horizontal axis. The first set-up family can be used to process the jobs r 1 , the second to process the jobs r 2 and r 5 , and the third to process the jobs r 3 and r 4 .
[0069] The expected value EW for the number of set-ups in the short-term planning period is as follows:
[0000]
EW
=
3
-
(
0.1
*
0.9
+
0.3
*
0.7
+
0.5
*
0.5
)
=
3
-
(
0.09
+
0.21
+
0.25
)
=
3
-
0.55
=
2.45
[0070] FIG. 3 b represents unbalanced set-up families with respect to absolute job frequencies. The expected value for the number of set-ups is the short-term planning period is now only 2.09 set-ups. Fewer set-up changeovers are therefore required, thereby permitting the efficiency of the pick-and-place line 110 to be improved.
[0071] Improved Solution with an Additional Set-Up Family
[0072] Hereinafter, it is demonstrated that it is not always better to pursue the target of a minimum number of set-up families. Modules and the number of corresponding jobs within the long-term planning horizon are given by the following:
[0000]
Module
r1
r2
r3
r4
r5
Number of jobs
90
50
50
10
10
pr
0.9
0.5
0.5
0.1
0.1
[0073] FIG. 4 a shows a breakdown of jobs into three set-up families. The expected value for the number of set-ups in the short-term planning period is 1.76 set-ups.
[0074] FIG. 4 b shows a breakdown involving four set-up families. The expected value for the number of set-ups in the short-term planning period is 1.65 set-ups:
[0000]
EW
=
4
-
(
0.1
*
0.5
+
0.5
+
0.9
+
0.9
)
=
4
-
2.35
=
1.65
Heuristics
[0075] The assignment problem can be formulated as a mixed integer non-linear optimization problem. It is assumed, however, that this problem can only be resolved with difficulty. Consequently, various heuristics are proposed hereinafter, in order to permit the resolution of the problem by means of linear optimization.
Heuristic 1
[0076] Using the method described in patent application DE 10 2012 220 904.2, set-ups can be constituted with a maximum number of jobs. Using this method, heuristic 1 involves the constitution of successive fixed set-up families, each with a maximum number of jobs. Accordingly, the set-up families are fully-packed, and the resulting number of set-up families is relatively low. Moreover, the last set-up families to be constituted include only very few jobs, which only increase the anticipated number of set-ups to a limited extent (c.f. the previous example in FIGS. 3 b and 3 c ).
Heuristic 2
[0077] In common with heuristic 1, heuristic 2, by the application of the aforementioned method, involves the successive constitution of set-up families cl from the quantity of residual modules. In this case, however, the target criterion:
[0000]
EW
(
cl
)
=
1
-
∏
r
∈
cl
(
1
-
p
r
)
[0000] assumes a maximum value in each case. To this end, in the method according to application DE 10 2012 220 904.2, the MIP target function is adjusted as follows.
[0078] R′ represents the quantity of residual modules, which are not yet incorporated in fixed set-up families. It is moreover assumed that pr<1 applies to all rεR′. Only one fixed set-up family/static set-up family cl is constituted. The following designation from MIP also applies:
[0079] Assign r,cl : a variable which indicates whether a printed circuit board r is assigned to a fixed set-up family cl. If an assignment exists, this variable assumes a value of 1, or otherwise assumes a value of 0.
[0080] The target function max EW(cl) can be formulated as a non-linear target function with the whole-number variables Assign r,cl :
[0000]
maximize
1
-
∏
r
∈
R
′
(
1
-
p
r
)
Assign
r
,
cl
[0081] This is equivalent to:
[0000]
minimize
1
-
∏
r
∈
R
′
(
1
-
p
r
)
Assign
r
,
cl
(*
)
[0082] The following also applies:
[0000]
∏
r
∈
R
′
(
1
-
p
r
)
Assign
r
,
cl
=
e
log
∏
r
∈
R
′
(
1
-
p
r
)
Assign
r
,
cl
[0083] As the exponential function increases in a strictly monotonic manner, and the following applies
[0000]
log
∏
r
∈
R
′
(
1
-
p
r
)
Assign
r
,
cl
=
∑
r
∈
R
′
log
(
1
-
p
r
)
Assign
r
,
cl
[0000] the target function (*) is equivalent to:
[0000]
minimize
∑
r
∈
R
′
log
(
1
-
p
r
)
Assign
r
,
cl
[0084] This target function is linear, and can thus be employed in MIP as a new target function. In one example, in which heuristic 2 is superior to heuristic 1, the modules and job numbers considered are as follows:
[0000]
Module
r1
r2
r3
r4
Number of jobs
90
50
50
50
[0085] It is assumed that r 1 is appropriate to only one further printed circuit board type in a set-up family, and that r 2 -r 4 are appropriate to a common set-up family.
[0086] FIG. 5 a shows the result of heuristic 1. The expected value for the number of set-ups in the short-term planning period is 1.775 set-ups.
[0087] FIG. 5 b shows the result of heuristic 2. The expected value for the number of set-ups in the short-term planning period is 1.7 set-ups.
Heuristic 3
[0088] If, by the application of heuristics 1 and 2 respectively, the minimum number of set-up families is exceeded, a further heuristic 3 is proposed.
[0089] FIG. 6 shows a flow diagram of a method 300 for heuristic 3. The method 300 commences with a step 305 , in which the quantity of printed circuit board types R′ yet to be assigned is equal to the original quantity of printed circuit board types R to be assigned. The present set-up family cl opt is blank in the first instance.
[0090] Thereafter, in a step 310 , the remaining modules from R′ are divided into set-up families, for example using the “method for constituting set-up families on pick-and-place lines” described in patent application DE 201 213 064, such that, in each iteration, a further alternative solution cl min is obtained respectively.
[0091] The combination of the solutions cl opt and cl min is evaluated in a step 315 with respect to the expected value for the number of set-ups in the short-term planning horizon, and the best solution is selected.
[0092] In a step 320 , it is decided whether further printed circuit board types are present in R′. If this is not the case, the method 300 terminates at step 325 . Otherwise, the method proceeds directly to a step 330 . Alternative or additional interruption criteria, such as the achievement of a maximum execution time or the constitution of a predefined number of fixed set-ups, are also possible.
[0093] In step 330 , again as in the case of heuristics 1 and 2, for example by the method described in DE 10 2012 220 904.2, a set-up family cl opt is constituted successively with respect to a maximum job number or a maximum expected value.
[0094] In a subsequent step 325 , cl opt is added to the set-up family quantity Cl opt . The printed circuit boards of cl opt are removed from R′. Thereafter, the method 300 continues with the aforementioned step 310 .
[0095] Although the invention has been illustrated and described in greater detail with reference to the preferred exemplary embodiment, the invention is not limited to the examples disclosed, and further variations can be inferred by a person skilled in the art, without departing from the scope of protection of the invention.
[0096] For the sake of clarity, it is to be understood that the use of “a” or “an” throughout this application does not exclude a plurality, and “comprising” does not exclude other steps or elements. | Provided is a method for populating printed circuit boards, which includes the steps of acquiring jobs, in each case relating to populating printed circuit boards of a printed circuit board type on the pick-and-place line, and associated probabilities by a job is to be executed in each case, assigning printed circuit board types of the jobs to set-up families, determining for each set-up family the characteristic number which comprises the sum of probabilities of those jobs, the printed circuit board types of which are comprised by the set-up family, optimizing the assignment in such a way that the characteristic numbers of different set-up families are as different as possible, providing a set-up from one of the determined set-up families on the pick-and-place line, and populating printed circuit boards on the pick-and place line. | 7 |
The present application claims priority of Japanese patent application No. 61-153250 filed on June 30, 1986.
FIELD OF THE INVENTION AND RELATED ART STATEMENT
This invention relates to a magnetic disk device which uses as a data recording medium, a metallic film disk having a smooth layer of magnetic material formed by spattering or plating.
Of all the data recording media used in conventional magnetic devices, a coating disk having a magnetic powder applied on the surface has assumed the leadership. In recent years, the growing trend in magnetic disk devices toward an increase in recording density has encouraged adoption of a magnetic film disk material formed by spattering or plating.
The magnetic film disk has an average roughness in the range of 0.01 to 0.002 μm as expressed by the Ra value. Compared with the coating disk whose Ra value falls in the range of 0.07 to 0.04 μm, the magnetic film disk material formed by spattering or plating has a high level of surface smoothness.
When a floating head possessing an extremely smooth slider surface lands on the disk of the foregoing description and remains in contact for a long time it adheres to the disk due to van der Waals forces.
In magnetic disk devices of the ordinary grade, the disk drive motors for rotating the disks (hereinafter referred to as "DDM") are given the smallest possible torques partly for the reason of production cost. These magnetic disk devices, therefore, have the disadvantage that their disks cease rotating.
OBJECT AND SUMMARY OF THE INVENTION
An object of this invention is to provide a magnetic disk device which warrants safe rotation of the disk even when the slider surface of the magnetic head and the disk develop the phenomenon of fast mutual adhesion.
The magnetic disk device of the present invention comprises disk rotating means for rotating a disk possessing a smooth recording surface, a magnetic head possessing a smooth slider surface adapted to contact the aforementioned recording surface when the disk is kept at rest, a carriage arm for retaining the magnetic head, carriage arm displacing means for changing the position of the carriage arm, a stopper enabled to change position into a closed state and an opened state and, in the closed state, control the movement of the aforementioned carriage arm, means for opening and closing the stopper, and control means for controlling the aforementioned disk rotating means, carriage arm displacing means, and stopper opening and closing means so as to enable the aforementioned carriage arm to swing with the stopper kept in the closed state.
In the magnetic device of the present invention, the carriage arm is able to swing with the stopper kept in the closed state when the disk is set rotating. Even when the disk and the magnetic head happen to come into mutual adhesion, therefore, they can be separated from each other and the disk can be easily set rotating.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a plan view illustrating the configuration of a typical device embodying the present invention,
FIG. 2, (A)-(E), is a flow diagram illustrating the operation of the typical device,
FIG. 3, (a)-(e), is a timing chart illustrating the operation of the typical device of the first embodiment with reference to relevant electric currents,
FIG. 4, (a)-(e), is a timing chart illustrating the operation of the typical device of the second embodiment of the present invention with reference to relevant electric currents,
FIG. 5, (a)-(e), is a timing chart illustrating the operation of the typical device of the third embodiment of the present invention with reference to the relevant electric currents, and
FIG. 6 is a plan view illustrating the configuration of an essential part of a further typical device embodying the present invention.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
Now, preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings.
FIG. 1 is a plan view illustrating the configuration of one typical device embodying the present invention.
The present embodiment represents application of the invention to a swing arm type magnetic disk device.
In the diagram, 1 stands for a disk having an extremely smooth layer of magnetic material formed on a surface by the process of spattering or plating, 2 for a DDM serving to impart rotation to the disk 1, 3 for a magnetic head adapted to effect writing and reading of data while being slightly floated up by the current of air generated during the rotation of the disk 1, 4 for a carriage arm adapted to support the magnetic head 3 and further move this magnetic head 3 substantially in the direction of the radius of the disk 1, and 5 for a voice coil motor (hereinafter referred to as "VCM") serving to change the position of the carriage arm 4.
Further, 6 stands for a hook-shaped stopper adapted to assume a closed state (the state resulting from the movement in the direction of the arrow A) and fix the carriage arm 4 so that the magnetic head 3 will be positioned in the contact-start-stop zone C 1 on the inner circumferential side of the disk 1, 7 for a projecting part formed on the carriage arm 4 side as opposed to the stopper 6, and 8 for a pin raised from the rear side of the projecting part 7 and adapted to control the change of position of the carriage arm 4 in the direction of the inner circumference of the disk 1.
Then, 9 stands for a solenoid for permitting change of position of the stopper 6 between the closed state (the state resulting from the movement in the direction of the arrow A) and the opened state (the state resulting from the movement in the direction of the arrow B) and 10 for a control circuit serving to control the DDM 2, VCM 5, and solenoid 9.
In the present embodiment of this invention, a gap M of a size of about 0.5 mm is formed between the leading end of the stopper 6 and the leading end of the projecting part 7 so that the carriage arm 4 may be allowed to move slightly between the stopper 6 and the pin 8 even when the stopper 6 is kept in the closed state.
Owing to this arrangement, the magnetic head 3 is allowed to change position on the disk 1 to the zone C 2 slightly on the outer circumferential side from the zone C 1 even when the stopper 6 is in the closed state thereof.
FIG. 2 is a flow diagram illustrating the operation of the device of the present embodiment. Now, the operation of this device will be described below with reference to FIG. 2.
After the device is connected to the main power source, the control circuit 10 permits flow of DC electric current to the VCM 5 for a duration of about 100 ms simultaneously with the start of the DDM 2 (Step A).
Subsequently, it permits flow of DC electric current in the reverse direction to the VCM 5 for a duration of about 100 ms (Step B).
The control circuit 10, with these steps of operation as one cycle, causes the carriage arm 4 to swing several times and then discontinues the flow of DC electric current to the VCM 5.
Since these steps enable the magnetic head 3 and the disk 1 to be separated from each other even after they have been in the state of mutual adhesion, the DDM 2 is able to start. Thus, the DDM 2 is set rotating normally (Step C).
Then, the control circuit 10 permits the flow of electric current to the solenoid 9 and causes the stopper 6 to assume the open state (Step D). Subsequently, it permits the flow of a prescribed magnitude of electric current to the VCM 5 in its normal routine and causes it to start a seek operation (Step E).
FIG. 3 is a timing chart illustrating all the aforementioned steps of operation with reference to the relevant electric currents.
In the chart, (a) stands for the main power source, (b) for the electric current caused to flow to the VCM 5, (c) for the electric current caused to flow to the DDM 2, (d) for the revolution number of the disk 1, and (4) for the electric current caused to flow to the solenoid 9.
As noted from this chart, the device of the present invention causes the carriage arm 4 to swing by alternately feeding DC electric currents flowing in opposite direction to VCM 5 simultaneously with the start of the DDM 2 after the connection of the device to the main power source. At this step, therefore, the disk 1 and the magnetic head 3 can be separated from each other even when they have been in the state of mutual adhesion and the disk 1 is able to rotate without fail.
In the present embodiment, the electric current is permitted to flow to the VCM 5 at the same time that the electric current flows to the DDM 2. In an alternative embodiment, as illustrated in FIG. 4, the electric current is first permitted to flow only to the VCM 5 and, after the magnetic head 3 and the disk 1 in the state of mutual adhesion have been separated from each other, the electric current is permitted to flow to the DDM 2.
Further in the device of this embodiment, the carriage arm 4 is caused to swing whether or not the disk 1 and the magnetic head 3 have developed the phenomenon of fast mutual adhesion. In a third embodiment, as illustrated in FIG. 5, the device is configured so that the presence or absence of the phenomenon of fast mutual adhesion between the disk 1 and the magnetic head 3 is discriminated (as by detection of a rotation error of the DDM 2, for example) and the carriage arm 4 is caused to swing only when fast mutual adhesion exists between the disk 1 and the magnetic head 3.
The device may be configured in a further embodiment so that the number of swings the carriage arm 4 is caused to produce is varied by the number of retries.
Generally, when the number of disks 1 falls in the range of 6 to 8, the largest coefficient of static friction per surface at which rotation is permitted is about 0.9μ.
In the conventional magnetic disk device, therefore, the DDM 2 fails to rotate when the degree of mutual adhesion between the disk 1 and the magnetic head 3 exceeds this magnitude of static friction.
The torque of the VCM 5 generally is large enough to cause change of the position of the carriage arm so long as the aforementioned largest coefficient of static friction per surface does not exceed 2μ.
This invention, therefore, is capable of amply coping with even the otherwise helpless situation involving unduly strong mutual adhesion between the disk 1 and the magnetic head 3. Thus, the disk 1 is always allowed to start safe rotation.
The device of the embodiment described above is configured so that the VCM 5 is utilized for changing the position of the carriage arm 4. This invention is not limited to this particular arrangement.
For example, the present invention can be equally applied to the magnetic disk device of the class which relies on a stepping motor or a DC motor to drive the carriage arm 4.
Further, in the device of the above embodiments, the carriage arm 4 is designed in the swing arm pattern so as to effect change of the position by rotation. Alternatively, this invention can be equally applied to the so-called linear type magentic disk device in which the carriage arm 4 will effect the change of position linearly.
The device of the foregoing embodiment is further configured so that the movement of the magnetic head 3 will be controlled by the hook-shaped stopper 6 and the projecting part 7 of the carriage arm 4. This invention is not required to be limited to this particular arrangement.
For example, as illustrated in FIG. 6, a gap M for play of the magnetic head 3 may be interposed between a bar-shaped stopper 6' and a depressed part 4a of the carriage arm 4 so that the movement of the magnetic head 3 will be controlled by the stopper 6' and the depressed part 4a.
As described above, the magnetic disk device of the present invention, in starting the disk, causes the carriage arm to swing with the stopper kept in the closed state. Even when the disk and the magnetic head happen to develop the phenomenon of fast mutual adhesion, therefore, the device readily separates them and permits the disk to be rotated without fail. | A magnetic disk device of the present invention is configured so that a stopper for controlling the movement of a carriage arm is adapted to give rise to play in controlling the carriage arm when the stopper is in the closed state. When a disk rotating means is actuated, the magnetic disk device permits a disk and a magnetic head in the state of fast mutual adhesion to be separated from each other by causing the carriage arm to swing with the stopper kept in the closed state, and consequently, the magnetic disk device enables the disk to rotate without fail. | 6 |
RELATED APPLICATIONS
This application is related to and claims priority from U.S. Provisional application 60/554,265 (filed 18 Mar. 2004).
TECHNICAL FIELD OF THE INVENTION
The present invention relates hairdryers and, more particularly, to an improved hairdryer in which the air intake is cleansed of dust particles with an electrostatic precipitator.
BACKGROUND OF THE INVENTION
It is known in the art to filter intake air into a hair dryer in order to cleanse the air, which is to be blown upon the head and face. Prior art filters have employed various direct filter medias of various densities. However, the coarse filters remove little dust and the fine filters interfere significantly with the airflow. A clogged filter can result in hairdryers that quickly overheat and, as a result, can cycle on and off during normal use.
It is known in the art to utilize electronic precipitators to cleanse air in room air cleaners by charging airborne dust particles and then collecting these charged particles in a grounded filter medium.
OBJECTS AND SUMMARY OF THE INVENTION
It is an object of the present invention to provide a hairdryer that overcomes the shortcomings of known hair dryers mentioned above. These and other objects are achieved by the present invention described herein.
The present invention avoids the problem of passive porous filters used in a hair dryer intake by employing an electronic precipitator to more efficiently remove air contaminants such as dust, smoke and pollen particles. The active filtration allows more efficient removal of airborne particles while reducing the resistance to the airflow.
A charged screen can be employed at the air intake to ionize air upstream of a grounded, porous media, with a potential between the screen and media of at least 3 to 10 KV. The collection media can made of a number of alternative porous and conductive materials, such as a carbon-loaded plastic foam, metallized glass fiber or metallic foam. The electrical activation of the downstream media allows a much coarser filter pore to be used than in a passive media. Alternatively an array of metal plates or an expanded metal or woven screen can also be used as a dust collector. Dust collecting media or plates can be designed for easy removal for cleansing.
An assembly of porous, dielectric foam sandwiched closely between opposing electrode screens can be used as the charging device and as a removable collecting cartridge. The proximity of the opposing electrical fields to the insulating filter media results in the dielectric material actively and efficiently collecting dust.
Alternatively, a grounded media or collection screens can be used downstream of a high Voltage, ionizing point source or a similar array of point sources. With these or similar ionizing and collection structures, intake air to a hairdryer can be efficiently cleaned with considerably less resistance to the airflow through the dryer.
The precipitator device can be designed to be switched on or off, and the device can also be switched selectively through various voltage levels to increase or decrease the amount of ionization and the filtering efficiency of the aircleaner. The insulation and electrode architecture is designed to avoid visible arcs or sparkovers.
The high voltage generation can be accomplished with a number of well-known electronic circuits. Coil windings and piezo crystals can generate sufficient voltage. The high voltage generator can be housed within the dryer body, within the handle of the dryer, inside the filter structure, pendant on the dryer supply cord, or at the wall plug. The generator and leads to the precipitator can be wired into the dryer or they can be designed with the generator and power supply cord independent of the hairdryer so that the active filter can be sold as an optional add on to a conventional hairdryer.
In addition, when the filter media does eventually become clogged with dust particles, the increased resistance will reduce the air intake. When the air volume is significantly reduced the dryer temperatures will climb. It is common to employ a “split circuit” in hairdryers, which switches out a large portion of the heater on a thermostat, while maintaining the dropping circuit to the motor. The present invention employs a neon light wired across the temperature-limiting thermostat of the split circuit, so that when the thermostat opens, the neon will see an increased current, sufficient to light, thereby indicating the need to clean the filter.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention is more fully understood by reference to the following detailed description of an illustrative embodiment with the drawings identified below.
FIG. 1 is an exploded view of the preferred embodiment of a hairdryer with and electronic precipitator on the air intake.
FIG. 2 is a schematic illustration, as well as a cross section, of the preferred embodiment of the electronic precipitator assembly.
FIG. 3 is an orthographic illustration and a partial section of an alternative electronic precipitator filter assembly.
FIG. 4 . is an orthographic illustration and a partial section of a second alternative electronic precipitator filter assembly.
FIG. 5 is a circuit diagram illustrating a neon lamp used as a warning indicator for a clogged air intake filter.
DETAILED DESCRIPTION OF THE INVENTION
Referring to FIG. 1 , the preferred embodiment of the present invention an improved hair dryer employing an electronic precipitator, is illustrated in an exploded schematic view. The device overall is made up of a handle and barrel housing ( 10 ), a removable filter assembly ( 2 ), a precipitator housing ( 4 ), a charging screen ( 1 ), a protective rear screen ( 3 ), a rear hairdryer housing ( 5 ), a fan ( 6 ), a motor mount ( 7 ), a motor ( 8 ), a heater assembly ( 9 ), a supply cord and strain relief ( 12 ), switches ( 11 ) and an indicator light ( 13 ).
FIG. 2 is a closer view of the exploded precipitator assembly as well as a schematic view of the assembled assembly. Also shown in Figure two is a cross sectional view of the assembly. The assembly is made up of a protective cover ( 3 ), a precipitator housing ( 4 ), a charging screen ( 1 ) and a grounded filter ( 2 ).
FIG. 3 shows an orthographic drawing of an alternative assembly of a removable filter ( 14 ) and a partial cross section of such a filter. The alternative construction employs a sandwich of charged metallic screens, a high voltage screen ( 15 ) and a grounded screen ( 16 ). Between the two charged screens is a pad of a porous, dielectric filter material ( 17 ) and an air gap ( 19 ). The screens mount and make electrical contact inside the hairdryer between two spring contacts ( 18 ).
FIG. 4 illustrates an additional alternative embodiment of an electronic precipitator employed on the intake of a hairdryer. In this alternative the ionization and charging of the intake air is accomplished with a corona discharge off a highly tensioned needlepoint ( 20 ) which is located upstream of a grounded filter ( 2 ).
FIG. 5 is an illustration depicting a circuit diagram for the preferred embodiment of the improved hairdryer that illustrates how a neon lamp ( 22 ) can be switched around a temperature limiting thermostat to indicate that the normally closed thermostat ( 21 ) is open. The thermostat will generally open due to overheating of the hairdryer as a result of a dirty intake filter. The lamp thus operates as a filter cleaning indicator and warning. Such a warning light will also, in addition, indicate other, generally significant problems, if cleaning the filter fails to eliminate the warning light. Such a warning light can be used with an electronic precipitator or alternatively with a passive filter system.
While a preferred embodiment of the invention has been herein disclosed and described, it is understood that various modifications can be made without departing from the scope of the invention. | A hairdryer air intake is cleansed of dust particles with an electrostatic precipitator. The precipitator consists of a charging device ( 1 ) and a grounded filter media ( 2 ) that can be removed and cleaned. A warning lamp ( 13 ) indicates the need to clean the filter. | 0 |
CROSS REFERENCE TO RELATED APPLICATION
This application is a continuation-in-part of our co-pending U.S. patent application Ser. No. 07/882,820, filed May 14, 1992, now U.S. Pat. No. 5,246,348.
FIELD OF THE INVENTION
The present invention relates to water inlets for liquid ring vacuum pumps, and more particularly to an apparatus, the use of which will result in lowering present maintenance time and cost over the operating life of the pump while retaining the efficiency of pump operation throughout its operating life, and for reducing the amount of fresh water required in the operation of the pump. Specifically the invention is a manifold for transporting secondary water into a liquid ring vacuum pump for cooling and operational purposes.
BACKGROUND OF THE INVENTION
Liquid ring vacuum pumps, as exemplified by Roe et al U.S. Reissue Pat. No. 29,747, which is incorporated herein by reference, use "seal water" for two purposes, first to form a liquid ring of working pistons that compress the gas and push it out of the pump, and second to form a seal between high pressure gas being discharged and low pressure gas entering the pump. This seal is formed in the angular segment land area of the 360 degree cycle, where the liquid ring pistons contact the cone surface. As used herein, the land, or land area, of the cone shall mean that portion of the cone which is in closest communication with the working water pistons. The efficiency of the pump depends on the seal created by both the clearance of the metal surfaces of the rotor vanes and cone surface and the pistons contacting the cone land area.
Shaft packing rings in a "stuffing box" require water for both sealing and cooling. If secondary (or recycled) water is pumped into the liquid ring pump through the center of the cone, then fresh water is piped separately into the stuffing box to avoid erosion of the shaft.
Metal parts of a liquid ring pump, particularly the vane surface at the inner tapered diameter of vanes and the cone land area surface, become worn during operation, causing an opening of clearances and subsequent loss of efficiency. After an extended time in operation, costly replacement or repair of the worn parts is required to rebuild the pump in order for it to perform anywhere approaching its original efficiency. Using only clean fresh water with known liquid ring vacuum pumps will reduce the cause for repair of such pumps, but with ever increasing costs for use of fresh water, and sometimes limited fresh water availability, use of 100% fresh water has become expensive or prohibitive. Also, the pre-treatment/filtration equipment necessary to remove suspended particulates from the secondary plant water to produce water with the degree of cleanliness that would minimize the erosive wear is both costly to purchase and expensive to operate and maintain. Additionally, a problem with using secondary plant water for sealing water is that it contains erosive particulates and will wear away the metal, both on the inner surface of the rotor vanes at the small diameter end of the tapered cone, and on the land area of the cone. This loss of metal weakens the liquid seal in the land area and causes an early loss of pump efficiency, thereby causing the need for costly pump repairs.
It is not recommended to use secondary plant water to seal and cool the shaft packing rings, since secondary plant water contains particles that would be captured between the shaft and packing, and cause excessive wear of the shaft material. Clean fresh water is piped separately to the stuffing box that holds the packing rings.
Secondary plant water can be used to form the piston of the pump, thereby saving fresh water. Secondary plant water contains sediment and particulates which over time will accumulate in the manifold delivery system. The result is an inadequate supply of secondary water to assure adequate cooling. To correct this condition it would be necessary to remove the manifold to clean out the accumulated sediment which is costly both in terms of down time of the pump and in labor costs.
DESCRIPTION OF THE PRIOR ART
Applicants are aware of the following U.S. Patents concerning
______________________________________U.S. Pat. No. Inventor Title______________________________________3,209,987 Jennings LIQUID RING PUMP3,743,443 Jennings VACUUM PUMPRe. 29,747 Roe et al. LIQUID RING PUMP LOBE PURGE4,747,752 Somarakis SEALING AND DYNAMIC OPERATION OF A LIQUID RING PUMP______________________________________
Jennings U.S. Pat. No. 3,209,987 is exemplary of liquid ring pumps over which the present invention is an improvement.
Jennings U.S. Pat. No. 3,743,443 teaches a seal apparatus in a central groove between successive stages, and a deflector blade for cooling the packing gland. The liquid is introduced into the pump through a pipe running parallel to the shaft and introduced into the pump around the cone in the middle of the rotor.
Roe et al. U.S. Reissue Pat. No. 29,747 teaches apparatus for purging or draining of contaminants from a liquid ring pump.
Somarakis U.S. Pat. No. 4,747,752 teaches apparatus for sealing the shaft and redirecting leakage toward a low pressure area. Here, liquid is introduced into the pump through a pipe just underneath the shaft of the pump. All the liquid is introduced in the same area.
SUMMARY OF THE INVENTION
The invention provides a manifold apparatus having a structure which allows quick and simple access to the interior of the manifold. The structure includes a water intake pipe which then branches off into usually four water discharge pipes. Opposite, and aligned with the same axis as the water discharge pipe is a cap or plug which is secured by means of a screw type threading. When water flow to the pipe becomes restricted, or on regularly scheduled intervals, sediment is removed by shutting off the water flow to the pump, removing the caps from the manifold, then inserting a brush, hook, or dowel rod into the manifold through the openings to clear out any sediment or debris which has accumulated therein. After the sediment and debris is cleared out the caps are replaced and secured, and the water flow is resumed.
During normal operation, secondary water is introduced through the housing wall into the annular peripheral space near the interior of the housing wall to provide the water necessary to form the working piston of the pump. Clean fresh water flows through the cone to the land area, forming a liquid seal.
The present invention solves the problem of sediment build-up within the manifold, which restricts the flow of water to the pump. At regularly scheduled intervals, the manifold is easily and quickly cleaned assuring that there will always be an adequate supply of secondary plant water to form the working piston of the pump.
The invention also solves the environmental problem caused by requiring too much fresh water in the operation of a liquid ring vacuum pump. Clean fresh water is only used where it is essential. Secondary plant water is used more effectively by delivering it to the location within the pump where its usage will cause the fewest problems. The invention uses secondary plant water more efficiently because the maintenance time associated with using secondary plant water has been drastically reduced.
OBJECTS OF THE INVENTION
The principal object of the invention is to provide apparatus for delivering fluid such as water through the water through a wall of a housing of a liquid ring vacuum pump.
It is also an object of the invention to provide means for reducing cleaning time to the secondary plant water manifold of a liquid ring vacuum pump.
Another object of this invention to provide quick access to the interior of the manifold.
Another object of the invention is to provide access to the intake water orifices on the liquid ring vacuum pump.
Another object of the invention is to provide a method of using inexpensive secondary plant water to form the working piston of the pump.
Another object of the invention is to provide an adequate seal at the cap in the manifold, to avoid leakage during normal operation.
A further object of this invention is to provide direct access to the manifold for the removal of sediment.
BRIEF DESCRIPTION OF THE DRAWINGS
The foregoing and other objects will become more readily apparent by referring to the following detailed description and the appended drawings in which:
FIG. 1 is an isometric view of a manifold adapted for flush mounting with a liquid ring vacuum pump.
FIG. 2 is an isometric view of a manifold having individual water outlet pipes.
FIG. 3 is a side elevational view of a liquid ring vacuum pump showing schematically secondary water injection, and associated control system.
FIG. 4 is a side elevational view of a liquid ring vacuum pump showing a manifold in place.
FIG. 5 is a schematic cross section of a liquid ring vacuum pump showing a working piston, and secondary water injection, in accordance with the present invention.
FIG. 6 is a side elevational view of the liquid ring vacuum pump of FIG. 3 showing alternative placements of the manifold.
FIG. 7 is an isometric view of an alternative embodiment of a manifold adapted for flush mounting on a liquid ring vacuum pump housing.
FIG. 8 is an isometric view of an alternative embodiment of a manifold having dual threaded outlet pipes, and two alternative manifold caps, a cap with square or nut-mounted head, and a cap with a hexagonal head.
FIG. 9 is an isometric view of another alternative manifold embodiment in which a flush mounted manifold has a water intake pipe connected to the end of the manifold distribution tube.
FIG. 10 is an isometric view of a further alternative embodiment in which a manifold has caps at both ends of the manifold distribution tube.
DETAILED DESCRIPTION
The four stages of liquid ring pump operation, which take place about specific angular segments of the cone, as depicted in FIG. 5, are: the gas inlet or intake stage A, the gas compression stage B, the compressed gas discharge stage C, and the liquid seal stage D, the last of which occurs at the land area.
Referring now to the drawings, in FIG. 1, a flush mount manifold 10 for make-up water of the liquid ring vacuum pump receives water through water intake pipe 12 and distributes the water across manifold distribution tube 16, which feeds the water directly into pump 30 through make-up water injection orifices or intakes 70, as seen in FIG. 3. The flush mount manifold 10 is provided with caps 14 for direct access to the interior of manifold distribution tube 16. Each cap 14 preferably is provided with threads 22 for engaging internally threaded cap receptacles in the manifold distribution tube 16. The orifices 21 of the manifold or the discharge pipes 20 can be inclined to mate and be in axial alignment with water injection inlets 70A, 70B, 70C or 70D, as shown in FIG. 5, whereby the axes of the opposing caps 14 will also be aligned with the axes of the mating orifices 70, 21 or orifices 70 and pipes 20, and parallel with each other cap axis. A nut-type square head 26 is used to remove the cap. The flush mount manifold 10 is affixed directly to the pump housing 34 by connecting flange 28 to the housing, as with bolts.
Overall, the pump 30 is shown without the manifold distribution tube 16 in FIG. 3. In operation, a motor 40 drives a shaft 32 through a bearing housing 36. Gas is injected into the pump through an inlet passageway 38. Make-up secondary plant water from a source 68 is fed into the pump through the manifold. The manifold distributes the water through the wall of the pump housing 34 through the injection orifices 70. The manifold distribution tube 16 is attached to the pump 30 as shown in FIG. 4. The manifold distribution tube 16 can be attached to the pump 30 at positions 80A, 80B, 80C, or 80D, as shown in FIG. 6. As indicated in FIG. 5, those positions on the exterior of the pump 30 correspond with positions 70A, 70B, 70C, and 70D in FIG. 5, which is a diagram of the inside of the pump. It is preferred that make-up water be injected tangentially in the same direction as the direction of rotation of the pump to avoid any extraneous water ejection along with compressed gas. The optimum location for make-up water injection is 70D opposite the land area section D.
ALTERNATIVE EMBODIMENTS
Alternatively, the standard mount manifold 18 may be mounted at a spaced distance away from the pump housing 34 by using water discharge pipes 20, shown in FIG. 2. Discharge pipes 20 each have a flange 29 shown in FIG. 2 and are mounted to the pump housing 34 by affixing each flange 29 thereto. In the alternative embodiment of FIG. 8, pipe 46 is threaded at both ends in opposite directions, whereby insertion of the pipe 46 in threaded manifold orifice 64 and in threaded housing orifice 70, then rotation of the pipe 46 attaches the manifold distribution tube 16 FIG. 8 to the pump housing 34 by drawing them together.
The cap 24 in FIG. 8 can also be provided with a torque fitting, allen, screw head or similar fitting in place of the nut 26. The cap 25 in FIG. 8 can have any convenient configuration such as hexagonal or square shape to facilitate removal with a wrench.
The water intake pipe 12 may be branched, or connected to the end of the manifold distribution tube 16 as shown in FIG. 9. A removable cap 14 is situated opposite the water intake pipe to provide access to the interior of the manifold distribution tube 16.
The cap 24 shown in FIG. 8 can be fitted with a gasket to insure a secure seal. A gasket may also be employed between the manifold distribution tube 16 and the pump housing when the tube 16 is bolted to the housing.
While the drawings show four discharge tubes 20 or orifices 21, (see FIG. 1), with opposed caps 14 on the manifold distribution tube 16, it is possible to use more or fewer tubes or orifices, depending on the pump design. Note that the depicted pump 30 is a double cone pump, with two intakes 70 for each cone.
The elongated flush mount manifold 10 may be cast or otherwise fabricated without a flange 28 as shown in FIG. 7. This manifold can be welded to the pump housing 34 or it may be cast directly into the pump housing 34.
Additionally a manifold 10 may employ a cap 14 at either or both ends of the manifold distribution tube 16 as shown in FIG. 10, or may employ both end caps and caps mounted axially with the orifices in the pump housing.
SUMMARY OF THE ACHIEVEMENT OF THE OBJECTS OF THE INVENTION
From the foregoing, it is readily apparent that we have invented an improved method and apparatus for effectively delivering secondary plant water, to be used in a liquid ring vacuum pump, through the wall of the pump housing. The manifold affords quick and easy access for cleaning, which will be necessitated by the use of secondary plant water, as well as an inspection port.
It is to be understood that the foregoing description and special embodiments are merely illustrative of the best mode of the invention and the principles thereof, and that various modifications and additions may be made to the apparatus by those skilled in the art, without departing from the spirit and scope of this invention, which is therefore understood to be limited only by the scope of the appended claims. | An improved water delivery system for a liquid ring vacuum pump which delivers water through the side of the pump wall. A manifold system aligns outlet ports of the manifold with the inlet ports of the pump itself. Access ports with plugs or caps are also aligned with the pump inlet ports, to provide a quick and easy access to clean out sediment from the manifold. The improved manifold system allows efficient employment of secondary plant liquid in the operation of a liquid ring vacuum pump. | 5 |
[0001] This application claims priority from provisional application 60/337,574, filed Oct. 22, 2001.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to commodes and toilets for ill and/or elderly people.
[0004] 2. Description of the Related Art
[0005] In the field of toilets, there are two types of seats, standard and elongated. While the exact dimensions can sometimes vary, a standard toilet, is a toilet having a generally round (or egg shaped) opening toilet, and which is installed in most homes and offices, etc. A standard toilet (sometimes referred to as a regular toilet), or also referred to as a household toilet (which is not the most accurate description as standard toilets are available in offices, commercial buildings, etc.) .
[0006] Standard toilet bowls are adapted to use standard toilet seats. The standard toilet seat has an opening commensurate with the opening of a standard toilet bowl.
[0007] On the other hand, an elongated toilet is generally defined as any toilet other than a standard toilet (except for a pediatric size) which has a larger opening than the standard toilet. Elongated toilet seats are adapted to fit on elongated toilets, which are generally more oblong, elliptical, and/or rectangular in shape (generally with rounded edges) , and has a larger open area than the more circular standard toilet.
[0008] Elongated toilets (and elongated toilet seats) are desirable for excessively obese patients, as well as people with certain medical conditions (swelling) where the standard toilet seat is too small.
[0009] Commodes are often used in hospitals, hospices, and are used in the homes by ill and elderly people because they provide support that is not available from a stationary toilet. Specifically, a commode generally comprises at least a front cross bar, a rear cross bar, and two side cross bars. A toilet seat usually is arranged so that at least two sides rest on either the front and rear crossbar, or the two side cross bars, to stabilize the seat.
[0010] A commode has a pan having an upper portion and a lower portion, the pan being arranged underneath the toilet seat. While the pan could have a solid bottom, most commodes have an opening in the bottom of the pan. The entire commode itself is arranged to be placed over a toilet, so that waste will be discharged from the opening in the bottom of the pan directly into the toilet. This permits a more hygienic design than a closed pan, which would have to be removed and discharged.
[0011] The upper portion of the pan has a generally arcuate surface extending downwardly from the upper portion of the pan to a generally circular bottom. Although the generally circular bottom is preferred, other shapes, (square, substantially triangular, rectangular, etc.) could be used. However, the prior art is lacking in providing a commode adapted to specifically accommodate the larger and ill patients.
SUMMARY OF THE INVENTION
[heading-0012] Three-In-One Commode
[0013] The present invention provides a three-in-one commode, the three features being a commode which has drop arms, an elongated toilet seat and a pan having an integrally formed or attached a splash guard adapted so that the commode can be positioned over a standard toilet, yet provide a user with the comfort of an elongated toilet. The pan, which communicates with the elongated toilet seat at an upper portion, is tapered downwardly to fit over or in a standard toilet bowl. The commode comprises a front cross bar assembly, a rear cross bar assembly, and two drop arms which are pivotally connected, slidably connected, or attachable/detachable from at least one of the front or rear cross bars so as to provide adjustable arm rests and provide support while getting on or off the commode, an elongated toilet seat arranged on top at least two opposing crossbars, and a pan arranged below the elongated toilet seat, said pan having an elongated upper portion which is tapered downwardly to a lower portion having an opening on the bottom, so that the lower portion fits over a standard toilet bowl, yet the commode provides the user with the comfort of an elongated toilet.
[0014] The arms rails provide an additional source of stability for a user to hold on while getting on or off the commode. There are often patients with mobility and balance problems, such as stroke patients, patients taking medications that can cause drowsiness, patients in wheelchairs and/or have multiple sclerosis and their need to use their arms to pull themselves onto or off of the commode because of weakness in their legs, just to name a few.
[0015] The three-in-one commode may optionally include side cross bars, the side cross bars are attached to portions of the front and rear cross bars by any of clamping, welding, bolting, riveting, bonding, spring loaded pins, etc.
[0016] Optionally, in an embodiment, the front cross bar assembly and the rear cross bar assembly have lower stabilizer bars which are formed so that a least a center portion of each lower stabilizer bar is in contact with the center portion of the other stabilizer bar, and can be clamped, welded, bolted, nailed, screwed, snapped, riveted, glued, or even sintered together. For purposes of illustration and not limitation, the rear stabilizer bar can be generally U-shaped, C-shaped, V-shaped, or L-shaped, and the front stabilizer can be shaped the same way, except that its orientation is changed so that the stabilizer bars will contact each other for at least a portion of their length. Generally, the rear stabilizer bar is formed so that the commode could be pushed from the front of a stationary toilet so that it fits over the stationary toilet, wherein the portion where the stabilizer bars contact each other serve an alignment function.
[0017] Optionally, the three-in-one commode could have a closed pan, or come with a bucket that either attaches to the pan, or positioned directly under the pan.
[0018] Optionally, in another aspect of the invention, a backrest may be attached to, extend from, or form part of the rear cross bar assembly.
[0019] The three-in-one commode permits heavy-duty support for ill and/or elderly people having problems with balance, walking, etc., by supporting the user via the drop arms arranged on the sides. In one embodiment, the three-in-one commode can support as much as 600 pounds in weight. In another embodiment, the three-in-one commode can support more than 1000 pounds of weight.
[0020] Optionally, a lower portion of the elongated toilet seat may have side rails by which the pan is slidably installed and/or removed from underneath the elongated toilet seat.
[0021] Optionally, the rim of the pan may be arranged over at least upper portions of the front and rear cross bars.
[0022] The elongated toilet seat can be attached by a hinge mechanism so as to be pivotally moved in a first position directly over the pan, and in a second position perpendicular to the upper surface of the pan, permitting removal for cleaning, etc.
[0023] Optionally, while the three-in-one commode provides the advantage of providing the comfort of an elongated toilet with the practicality of being adapted for use over a standard toilet seat, in an embodiment, the commode could be adapted to be positioned over an elongated and/or non-standard toilet bowl.
[0024] Optionally, the height of the commode can be adjustable by having an upper portion of the front cross bar and rear cross bar being arranged so as to be telescopically arranged in tubular lower portions, and a pin or key can be used to adjust the height defined by a series of holes in both the upper portion and lower portions of the cross bars, the holes which need to be aligned so that the pins or keys can penetrate the aligned holes.
[0025] Optionally, the height of the arm rests can be adjustable by having the upper portions of the side cross bars being telescopically arranged in tubular lower portions of the side cross bars, and a pin or key can be used to adjust the height defined by a series of holes in both the upper portion and lower portion, the holes which need to be aligned so that the pins or keys can penetrate the aligned holes.
[0026] Optionally, a toilet paper roll can be attached anywhere on frame of the three-in-one commode, meaning anywhere on any of the front, rear and/or side cross bars.
[0027] Optionally, the three-in-one commode can have non-skid feet attached at the bottom, to decrease the possibility that a person with mobility problems is not injured by the commode sliding while a person is mounting or dismounting same.
[0028] The downward tapering of the pan is optionally tapered downward and toward the back, allowing for a an improved splash guard function as the liquid flowing into the pan will tend to contact the upper portion of the pan in the front and roll downward toward the opening. This design prevents the ricochet of fluids off the sidewalls of the pan, keeping the user dry and providing a more hygienic commode than heretofore known in the prior art.
[0029] For purposes of illustration and not limitation, preferably the angle in the front is approximately 45 degrees, as a lower angle tends to make the front portion too flat, which will increase the possibility of ricochet, and a higher angle than 45 degrees may also contribute to increased splatter. However, this 45 degree angle is intended only for one particular aspect of the invention, and a person of ordinary skill in the art should understand that the presently claimed invention is not limited to a 45 degree angle in the front of the pan, and can be any angle as a predetermined, so long as there is a downward tapering so that the elongated opening fits into a standard toilet.
[0030] Optionally, in another aspect of the present invention, there can be two pan support bars connecting the front cross bar to the rear cross bar along the top of each cross bar, the pan support bars being spaced apart sufficiently so that the pan can be placed therebetween, and a rim along the edge of the pan can rest stably on the pan support bars.
[heading-0031] Waste Diverting Toilet Seat
[0032] The present invention includes a waste diverting toilet seat, wherein the seat and splashguard comprise a single unit. The waste diverting seat can be integrally formed from a single mold, or the seat and splashguard can be joined by any known method, such as adhesive, sintering, fasteners, bolts, screws, pins, nails, or even temporary connections such as Velcro. In addition, the splashguard make snap into the toilet seat, which is adapted to receive the splashguard. Alternatively, the splashguard or toilet could have flanged surfaces adapted for slidable installation and removal along rails formed in a portion of the toilet seat. For example the thickness of the seat could be reduced at a front portion so the flanged front of the splashguard fits in rails formed on a lower portion of the seat.
[0033] The portion of the splashguard that fits into the toilet seat may optimally have a thickness so as to fill in the reduced thickness of the front portion of the seat so that the thickness of the seat that rests upon the upper surface of a toilet bowl is approximately equal.
[0034] Alternatively, the waste diverting seat may have the front portion of the toilet seat (that receives or is attached to the splashguard) oriented at a slight incline to add in the diversion of the waste down the splashguard and toward the back of the lower portion of a toilet bowl, where the opening to the sewage pipe is situated.
[0035] The waste diverting seat may also have a splashguard with a spiral inner configuration to aid in centrifugal action of the waste as it is diverted down into the toilet bowl.
[0036] The waste diverting toilet seat can have a standard opening, or elongated opening, these sizes being known by persons of ordinary skill in the art.
[0037] The waste diverting toilet seat may also have a provide an elongated opening for a toilet bowl having a standard opening (The terms for elongated and standard being known to persons of ordinary skill in the art). This particular embodiment would extended beyond the front portion of a standard toilet bowl, and the splashguard formed in the waste diverting toilet seat would be tapered back toward the standard toilet opening because it would be arranged in a channel, groove, or void in the lower portion of the toilet seat, preferably toward the front. The thickness of the seat should be chosen to provide the clearance necessary for a person to sit on an elongated seat, and if they were sitting toward the front of the seat, not physically contact the front of the toilet seat. This could be a approximately several inches thick, optionally but in no way limited to at least three inches. Of course, an approximate two inch thick seat, or any number (such as four inches, six inches eight inches, etc. ) would be within the spirit and scope of the invention. The thicker toilet seat would assist ill/elderly people because they would not have to sit as low as they would on a standard toilet seat, yet have the comfort of an elongated opening with a splashguard so that the waster diverting seat can be arranged on a standard size opening toilet bowl.
[0038] The waste diverting seat could be used in homes, hospitals, hospices, doctors offices, offices, public restrooms, anywhere that accomodates a toilet.
BRIEF DESCRIPTION OF THE DRAWINGS
[0039] FIG. 1 is a perspective view of one embodiment the three-in-one commode according to the present invention.
[0040] FIG. 2 . is bottom view of the embodiment shown in FIG. 1 , showing the arrangement of the pan, which slides along rails underneath a stationary seat. FIG. 3 a bottom view of the embodiment shown in FIG. 2 , rotated by 90 degrees to illustrate the arrangement of the rear cross bar and the rear stabilizer bar.
[0041] FIG. 4 is a rear view of the first embodiment.
[0042] FIG. 5 is a plan view of the first embodiment, illustrating the view of the tapered pan, which includes a splashguard integrally formed therein.
[0043] FIG. 6 is the plan view of FIG. 5 rotated by 90 degrees.
[0044] FIG. 7 is a plan view illustrating how an elongated opening in the toilet seat is adapted for use over a standard toilet by tapering the pan downward from the front of the elongated opening toward the back, so that the opening of the pan fits in or over a standard toilet opening.
[0045] FIG. 8 shows an embodiment where the opening is more central arranged relative to the elongated opening in the toilet seat than the illustration shown in FIG. 7 .
[0046] FIG. 9 illustrates another embodiment of the present invention, wherein the commode has a standard weight capacity (a person or ordinary skill in the art knows and understands what the term standard weight capacity means with regard to commodes). The toilet seat is hinged in the back so as to be flipped substantially perpendicular to the upper opening of the pan, or parallel to the upper opening of the pan when in use.
[0047] FIG. 10 is a plan view of the embodiment shown in FIG. 9 , showing how the elongated opening of the pan matches the opening of the toilet seat, then tapers downward and back so as to provide a splash guard function while permitting the comfort of an elongated toilet seat in use with homes having a standard toilet bowl.
[0048] FIG. 11 illustrates how the elongated toilet seat of the three-in-one commode of the present invention can be pivoted by hinges, and wherein in lieu of a pan, the seat is attached to a splash guard without an actual pan, because the splash guard is adapted to be positioned over a standard toilet bowl.
[0049] FIG. 12 illustrates a bottom view of the embodiment depicted in FIGS. 9 and 10 , wherein the pan support bars can be seen providing support to the rim of the pan, which extends over portions of the support bars.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0050] FIG. 1 illustrates an embodiment of a three-in-one commode according to the present invention. While this embodiment is a heavy-duty commode, which permits weight capacities up to 600 lbs, the invention is not limited to this weight. For example, the same basic structure can be used to permit capacities of 1000 lbs. or more, or it could also be made to support a standard weight.
[0051] Normally, for reasons of safety, it is preferred that the commode be able to provide a minimum of 300 lbs. of support, because of the possibility that it can be used in care facilities as well as home use, and there is a possibility that even the intended user weighs far less than 300 lbs., another person who is considerably heavier but in the high end of the normal range of weight could use the commode without risk of injury.
[0052] FIG. 1 shows a frame comprising a front cross bar assembly 100 , a rear cross bar assembly 110 , drop arms 120 , a stationary seat 130 (this seat could be removable, pivotable or slidably detachable from the frame) and a pan 140 .
[0053] The arms 120 are shown where the left arm is in an upright locked positioned, but the right arm is in an unlocked positioned. There can be instances where locking and using only one side is preferable, for example, when a person suffering from paralysis on one side needs the assistance of a care-taker to get on and off the seat. By keeping one rail down, this could assist the caretaker in holding on and providing support to the patient's weak side during the seating and dismount from the commode.
[0054] The arms, also referred to as “drop arms” could be pivotable, slidable, and snappable, include fasteners, which can be fastened and or unfastened by the user. The arms may have a series of holes therein whereby a pin and or bolt is arranged, which may or may not be spring loaded, can be used to adjust and or lock the arm into position. In the depicted embodiment in FIG. 1 , clamps 150 are used. The clamps could be tensioned to remain closed but have a space in a center portion just slightly smaller than the width of each of the arms, so that the arm is pushed into the clamp and remains held in place by the bias in the closed position. Alternatively, there could be spring-loaded clips, pins, etc, which are pushed into the clamps after the arm is positioned in place. The arms could pivot from a lower position horizontally, vertically, or a combination of the two, depending on the particular shape of the arms, the type of clamp or fastener.
[0055] The backrest 160 , may telescopically extend out of the rear cross bar, or it could be attached by any known method. The backrest is not required, and could either be adjustable, or permanently welded into position, if present. The backrest in the depicted embodiment has a U-shape, but the artisan understand that any shape (e.g. V-Shape, C-shaped, L-shaped, A-shaped, tapered, round, oval, triangular, polygonal) could be used.
[0056] As shown in FIG. 2 , the seat 130 has two side rails 210 which are spaced apart at a predetermined length to permit the pan 220 , having a rim 230 , slide in and out of the rails for cleaning and/or storage.
[0057] The pan 220 has an opening on the bottom to permit the commode to be arranged over a standard toilet. Alternatively, the commode could be positioned over a bucket, or a bucket could be attached to the pan but providing, for example, a flanged rim on the bottom of the pan, so that a bucket could be slide thereon.
[0058] FIG. 2 also shows the front stabilizer bar 240 and the rear stabilizer bar 250 . As shown in the figure, the front stabilizer bar attaches to the front cross bar, and the rear stabilizer bar attaches to the rear cross bar. Both stabilizer bars are formed so that at least a portion of the stabilizer bars is in contact with each other to provide the additional stability. FIGS. 3 and 4 also show different views of the stabilizer bars.
[0059] In the depicted embodiment, the stabilizer bars are welded. However, they could be epoxied, sintered clamped, riveted, bolted, clipped together by retaining pins, etc. Also, there does not have to be literal contact between the stabilizer bars, although this is the preferred embodiment. In other words there could a clamp which has center portion that is wedged between the stabilizer bars and the when the clamp is closed, the stabilizer bars are not in literal contact with each other but are in contact with the clamp (or other fastener).
[0060] It is to be understood that the particular bending of the stabilizer bars is not the only way by which they can be formed so as to be joined, clamped, clipped, glued or welded together. While the bars can be joined according to predetermined needs for stability, the particular arrangement shown in FIG. 2 illustrates that the front stabilizer bar 240 does not have as pronounced of a bend as the rear stabilizer bar.
[0061] This forming of the stabilizer bars can be made so as to position the opening of the pan directly over a standard towel bowl, where the rear bar is has a more pronounced bend so that the rear stabilizer bar fits around the base of a standard toilet bowl, at such a positioned that when the stabilizer bar is close to contact with the standard toilet, the opening of the pan is centered over the opening of the standard toilet bowl, preferably over the portion where having the water remains when a toilet is ready for flushing.
[0062] The pan itself has an elongated upper portion comprising a splashguard that tapers down to the bottom opening. This permits the commode to have an elongated toilet seat with an elongated opening, but allows for easy usability with a standard toilet bowl. Of course, the commode could also be positioned over an elongated toilet bowl, but the advantage lies in that many homes, hospitals, hospices, health care facilities and offices have standard size toilet bowls.
[0063] The splashguard portion 510 of the pan 250 is shown in an overhead view in FIG. 5 and FIG. 6 . In addition, FIG. 7 , which is a plan view of the pan shown in FIG. 2 , shows how the splash guard is formed so that fluids would flow back and down toward the opening of the pan. The splash guard provides a much more hygienic commode than previously known, and allows for the use of an elongated toilet seat having an elongated opening, which via the structure of the splash guard, is formed for use with a standard toilet bowl.
[0064] Optionally, the interior of the splashguard and the pan could be spirally formed to cause the fluid to centrifugually travel a spiral path downward prior to exiting the pan. This improvement could reduce the splashing upward if the angle of exit is something other than substantially perpendicular to the water in the toilet bowl. Also, the spirals could be designed for counter-clockwise and clockwise flow, to facilitate flushing in both areas above and below the equator, because in these geographical areas the orientation of the rotation of drainage is different.
[0065] FIG. 2 also shows that the commode has feet 260 , which are optional. Preferably, the feet are made of a non-skid material to reduce the possibility of the commode sliding while a user is getting on or off.
[0066] FIG. 7 shows a much more pronounced difference between the elongated opening of the toilet seat and the opening of the pan at the bottom where fluid is discharged. Alternatively, the pan can be adjusted to fit at several positions below the seat to allow for custom centering of the pan over a standard toilet, elongated toilet, bucket, etc.
[0067] FIG. 8 shows a different position of the pan with regard to the seat than shown in FIG. 7 .
[0068] FIG. 9 shows yet another embodiment, where heavy-duty use is not required. In this three-in-one commode, an elongated toilet seat 910 is arranged to fit over the opening of the pan 920 . The pan itself has flanged edges that are used to position same on pan support bars 930 . In this embodiment, the pan support bars are arranged from front to back, but they could be arranged from side to side. This pan also has a splash guard portion 940 which permits more hygienic use and serves to guide the fluid to an opening suitable for positioning over the opening of a standard toilet bowl, while allowing the advantages and comfort of an elongated toilet seat and elongated opening.
[0069] FIG. 10 is a plan view of the embodiment shown in FIG. 9 . It should be noted that an artisan understands that the toilet seat can be hinged to the rear cross bar, backrest, and could even be pivotally attached to side bars or side rails.
[0070] FIG. 11 depicts how a toilet seat and splashguard can be pivotally attached to the commode. It should be understood that the splashguard is not required to be integrally formed with the pan, although such construction is preferred. For example, the splash guards could attached to the toilet seat (the toilet seat could be any of elongated, standard or pediatric) and provide direction of the fluid to a separate pan.
[0071] Finally, FIG. 12 is a bottom view of the embodiment depicted in FIG. 9 , showing the pan support bars, in this embodiment, being attached to a horizontal support. It is by the artisan that the pan support bars can be connected to other portions of the frame (sides) etc., that would not depart from the spirit and scope of the invention.
[heading-0072] INVENTION NOT LIMITED TO DEPICTED EMBODIMENTS
[0073] It is understood by an artisan that many modifications may be made from the embodiments depicted and/or described which does not part from the spirit and scope of the invention.
[0074] It is to be understood by persons of ordinary skill in the art that the present invention shown in the drawings and described herein are for purposes of illustration, not limitation. An artisan understands and it is well within the spirit and scope of the claimed invention that minor changes might be made to the depicted embodiments that do not depart from the invention. For example, the shapes of the crossbars do not have to be U-shaped, as they could be A-shaped, V-shaped, C-Shaped, L-shaped. square, square with rounded edges, square with chamfered edges, round, partially oval, oblong, have acute angles of intersection, have obtuse or right angles of intersection, can be a single piece, can made from multiple pieces joined together which can be pivotable, slidable, snap at least partially within one another, telescopically extended from a least a portion of each other.
[0075] Furthermore, the siderails can have polygonal shapes whereby only a handle portion extends up from two ends which are adjoined at lower ends to clamps, cross bars, side bars, legs, support bars, stabilizer bars, etc. The adjustable height can be lockable by any known method known to an artisan, including but not limited to cotter pins, flat pins, bolts, wing nuts. through-shafts, rivets, nails, bolts, etc.
[0076] It should also be understood that while the preferred material for the commode frame is metal, any substance having sufficient durability, such as plastic or wood, could be used for portions of, or all of the structure of the commode frame provided that the material can withstand the weight capacity. Further, care should be exercised so that a material is not chosen that is either too brittle that the structure could crack when under stress, or too deformable so as to bend or become misaligned, which could also be a source of injury, as persons using these type of structure are often in poor health and/or just had major surgery, and often have problems with balance and walking. | A three-in-one commode with waste diverting capability is disclosed for use by elderly or infirm people wherein the commode can interface with both a standard and an elongated toilet, yet provides the comfort and ease of use of an elongated size toilet seat for the users. | 8 |
FIELD OF THE INVENTION
[0001] This invention relates to delivery vectors for antigen producing genes (heterologous gene sequences or fragments thereof) used to generate immune responses in commercial pigs susceptible to decimation by disease. Such vectors are especially useful for the preparation of vaccines which can be easily administered on a large scale to protect pigs against disease. This invention also relates to a method of production of suitable delivery vectors, to methods of preparation of vaccines based on the vectors, to administration strategies and to a method protecting pigs from disease.
BACKGROUND
[0002] The productivity of the intensive pig industry depends on the control of infectious diseases. Whilst diseases can be controlled in part by good hygiene and quarantine measures, the industry must still rely on vaccination to protect herds. In a commercial situation, the cost per animal is high in terms of feed and current disease control costs and therefore, the costs in disease prevention and control by any newly proposed vaccine must be cheap, effective and easy to deliver.
[0003] Conventionally, vaccines constituting, live viral particles have been prepared by virus passage and selection of attenuated forms. Alternatively, killed vaccines were prepared from virulent viruses.
[0004] The most recent description of the use of viral vectors in the control of disease in pigs was the deletion mutant of pseudorabies virus for the control of Aujesky's disease. The use of a herpesvirus as a vector has the advantage of being able to stimulate a humoral and cell-mediated response, thus providing possible life long protection. Another advantage is the ability to insert other heterologous sequences in this vector, being expressed from a suitable promoter, to produce antigens for exposure to the animals immune system, thus protecting against two diseases. There are disadvantages of this system. Firstly, there is the issue of latency. Herpesviruses have the ability to integrate into the neurons in ganglia for the life of the animal. It only requires a suitable stress on the animal to cause the reactivation of the virus and consequently full disease. However, it is now known that the deletion of a specific gene, glycoprotein E, will attenuate the virus and prevent reactivation from latency. Therefore, this deletion vector is now widely used as an eradication vector for Aujesky's disease and subsequently will not be available as a suitable vector for the delivery of other antigens.
[0005] It is thus the aim of this invention to provide a delivery vehicle for heterologous sequences of genetic material that is particularly suited to administration on a large scale.
[0006] In particular, it is the aim of this invention to provide or enhance means for generation and/or optimisation of antibodies or cell-mediated immunity so as to provide protection against infection with common porcine diseases. It is an additional aim to provide a process for preparation of a suitable means for generation and/or optimisation of antibodies or cell-mediated immunity so as to protect pigs against infection with common porcine diseases. It is a further aim to provide a protection strategy.
SUMMARY OF INVENTION
[0007] The invention provides, in one embodiment, a recombinant porcine adenovirus capable of expressing DNA of interest, said DNA of interest being stably integrated into an appropriate site of said recombinant porcine adenovirus genome.
[0008] In another embodiment the invention provides a recombinant vector including a recombinant porcine adenovirus which stably incorporates at least one heterologous nucleotide sequence. Preferably the heterologous nucleotide sequence is capable of expression as an antigenic polypeptide. The antigenic polypeptide encoded by at least one nucleotide sequence is preferably foreign to the host vector.
[0009] In a further embodiment of the present invention the heterologous nucleotide sequence is capable of expression as an immuno-potentiator molecule.
[0010] It is also to be understood that the heterologous nucleotide sequence may encode for and/or express, an antigenic polypeptide and an immuno-potentiator molecule.
[0011] The recombinant vector may comprise a live recombinant porcine adenovirus in which the virion structural proteins are unchanged from those in the native porcine adenovirus from which the recombinant porcine adenovirus is produced.
[0012] This invention is partially predicated on the discovery that there are non-essential regions in the porcine adenovirus genome which do not correspond to those characterised previously on other adenoviruses thus making this virus particularly suited to delivery of heterologous sequences.
[0013] This invention is also predicated on the discovery that the porcine adenovirus generates a prolonged response in pigs thus making it well suited as a vaccine vehicle. Furthermore, the existence of a number of serotypes specific to respiratory or gastrointestinal tracts, allows the selection of a vaccine vehicle suited to a target organ and the type of immune response required.
[0014] The invention is also predicated on the discovery that porcine adenovirus can package genomic DNA greater than the 105% rule for mammalian adenoviruses with intermediate size genomes and that the resultant packaged virions are stable in vitro and in vivo.
[0015] Adenoviruses are a large and diverse family, having been isolated from many living species, including man and other mammals as well as a variety of birds. As a result adenoviruses have been separated into at least two genera, the Mastoadenoviridae and the Aviadenoviridae, and more recently a third genera has been proposed, the Atadenovirdae, which includes some bovine and avian adenoviruses (egg drop syndrome) (Benkö and Harrach, Archives of Virology 143, 829-837, 1998).
[0016] Porcine adenoviruses are prevalent infectious agents of pigs and to date four distinct serotypes have been recognised (Adair and McFerran, 1976) and evidence for at least one more (Derbyshire et al., 1975). Of the four serotypes found, three (serotypes 1 to 3) were isolated from the gastrointestinal tract while the fourth was recovered from the respiratory system. The porcine adenoviruses are considered to be a low pathogenic widespread agent and although isolations were made in general from diseased animals, it was most likely that the adenovirus was present only as a secondary infection. They have been isolated from pigs with diarrhoea and respiratory infections but it has been considered that at least the gastrointestinal adenovirus infections are usually asymptomatic (Sanford and Hoover, 1983). Porcine adenoviruses are spread by ingestion or inhalation and experimental infection via oral, intranasal and intratracheal inoculations have resulted in uptake of the virus. Experimental pathogenicity studies have shown that the primary sites of infection are the lower small intestine probably the tonsil (Sharpe and Jessett, 1967; Shadduck et al., 1968). With serotype 4 infection, a viraemia appears to develop in experimental infections. However, this may be a less common manifestation with the gastrointestinal serotypes (Shadduck et al., 1968). Faecal excretion is the most common cause for spread of PAV, being present for several weeks post infection. Nasal shedding also occurs under experimental conditions. PAV's role in pneumonia has been suggested to be that of either a predisposing factor or a synergist (Kasza et al., 1969; Schiefer et al., 1974) but experimental pneumonia with serotype 4 did not require a second agent to produce disease (Smith et al., 1973).
[0017] Porcine adenoviruses have yet to be examined in much detail and little is known about their role in disease or how common they are. This is due to the fact that they do not produce any significant disease in herds and have failed to draw the interest of industry through loss of production. It is likely that the number of serotypes of porcine adenoviruses is much greater than four and that it probably exists in the majority of pig herds as a normal commensal.
[0018] Work done on porcine adenovirus in regards to its morphology and molecular biology, has shown some similarities with other Mastadenoviruses examined. Its morphology is that of other adenoviruses examined with an icosahedral capsid containing a core of a double stranded DNA genome. Very little work on the characterisation of the PAV genome has been published (Benkö et al, 1990, Kleiboeker et al., 1993, Reddy et al., 1993, Kleiboeker, 1994). The size of the PAV genome (approx. 34.8 kb) is slightly smaller than that of human adenoviruses (approx. 35.9 kb). One study has shown using hybridisation with DNA probes from the total genome of human adenovirus type 2 that there is reasonable DNA homology between the porcine and human adenoviruses (Benkö et al., 1990). A recent report on the serotype 4 PAV demonstrated that its genomic layout was also similar to that of the human adenoviruses in the area of the L4 and E3 regions (including the 33K and pVIII genes) even though the sequence homology was not as strong as may have been expected (Kleiboeker, 1994).
[0019] While choosing appropriate PAV for development as a live vectors to deliver vaccines to pigs, it is important to take into account the natural prevalence of serotypes. Those serotypes not commonly encountered in the field have an obvious advantages over those to which pigs are frequently exposed and to which they may have developed immunity.
[0020] A further consideration is the ability of the vector to remain active in the pig beyond the period which maternal antibodies in colostrum protect pigs immediately post-birth.
[0021] Other important considerations in choosing potential PAV vectors are pathogenicity and immunogenicity. Preferably live vector viruses should be highly infectious but non-pathogenic (or at least attenuated) such that they do not themselves adversely affect the target species.
[0022] The preferred candidates for vaccine vectors are non-pathogenic isolates of serotype 4 (respiratory) and serotype 3 (gastrointestinal). Serotype 3 has been chosen as the serotype of choice due to excellent growth abilities in continuous pig kidney cell lines. The isolation of other serotypes, which seems likely, may well alter this selection. It is notable that the more virulent strains produce a greater antibody response.
[0023] Heterologous nucleotide sequences which may be incorporated into non-essential regions of the viral genome and which may encode the antigenic determinants of infectious organisms against which the generation of antibodies or cell-mediated immunity is desirable may be those expressing antigenic determinants of intestinal infections caused by gastrointestinal viruses; for example rotavirus or parvovirus infections, or respiratory viruses, for example parainfluenza virus, or that of Japanese encephalitis.
[0024] Heterologous nucleotide sequences which may be incorporated include the antigenic determinants of the agents of:
Porcine parvovirus Mycoplasma hyopneumonia Porcine parainfluenza Transmissable gastroenteritis (porcine coronavirus) Porcine rotavirus Hog cholera virus (Classical swine fever) Swine dysentery African swine fever virus Pseudorabies virus (Aujesky's disease virus) in particular, the glycoprotein D of the pseudorabies virus Porcine respiratory and reproductive syndrome virus (PRRSV) Heterologous nucleotide sequences more preferred for incorporation in the vectors of the invention are those expressing antigenic determinants of porcine parvovirus, porcine rotavirus, porcine coronavirus and classical swine fever virus.
[0036] It is also envisaged the heterologous sequences incorporated may be immuno-potentiator molecules such as cytokines or growth promoters, for example porcine interleukin 4 (IL4), gamma interferon (γIFN), granulocyte macrophage colony stimulating factor (GM-CSF), granulocyte colony stimulating factor (G-CSF), FLT-3 ligand and interleukin 3 (IL-3).
[0037] The type of immune response stimulated by candidate vectors may affect the selection of heterologous nucleotide sequences for insertion therein. PAV serotypes 1, 2 and 3, which naturally infect via the gut may induce local mucosal immunity and are thus more suitable for infections of the intestines (eg classical swine fever virus). PAV serotype 4, which naturally infects via the respiratory system, may be more suitable for infections of the respiratory tract (eg porcine parainfluenza) may also induce good local immunity.
[0038] The DNA of interest which may comprise heterologous genes coding for antigenic determinants or immuno-potentiator molecules may be located in at least one non-essential region of the viral genome.
[0039] Non-essential regions of the viral genome which may be suitable for the purposes of replacement with or insertion of heterologous nucleotide sequences may be non-coding regions at the right terminal end of the genome at map units 97 to 99.5. Preferred non-coding regions include the early region (E3) of the PAV genome at map units 81-84.
[0040] The heterologous gene sequences may be associated with a promoter and leader sequence in order that the nucleotide sequence may be expressed in situ as efficiently as possible. Preferably the heterologous gene sequence is associated with the porcine adenoviral major late promoter and splice leader sequence. The mammalian adenovirus major late promoter lies near 16-17 map units on the adenovirus genetic map and contains a classical TATA sequence motif (Johnson, D. C., Ghosh-Chondhury, G., Smiley, J. R., Fallis, L. and Graham, F. L. (1988), Abundant expression of herpes simplex virus glycoprotein gB using an adenovirus vector. Virology 164, 1-14).
[0041] The splice leader sequence of the porcine adenovirus senotype under consideration is a tripartite sequence spliced to the 5′ end of the mRNA of all late genes.
[0042] The heterologous gene sequence may also be associated with a poly adenylation sequence.
[0043] Instead of the porcine adenoviral major late promoter, any other suitable eukaryotic promoter may be used. For example, those of SV40 virus, cytomegalovirus (CMV) or human adenovirus may be used.
[0044] Processing and poly adenylation signals other than those of porcine adenoviruses may also be considered, for example, that of SV40.
[0045] In a further aspect of the invention there is provided a recombinant vaccine for generating and/or optimising antibodies or cell-mediated immunity so as to provide or enhance protection against infection with an infectious organism in pigs, the vaccine including at least one recombinant porcine adenovirus vector stably incorporating at least one heterologous nucleotide sequence formulated with suitable carriers and excipients. Preferably the nucleotide sequence is capable of expression as an antigenic polypeptide or as an immuno-potentiator molecule. More preferably, the heterologous nucleotide sequence may encode for and/or express, an antigenic polypeptide and an immuno-potentiator molecule.
[0046] The antigenic polypeptide encoded by the at least one nucleotide sequence is preferably foreign to the host vector. At least one nucleotide sequence may be associated with a promoter/leader and a poly A sequence.
[0047] The recombinant vaccine may include live recombinant porcine adenovirus vector in which the virion structural proteins are unchanged from that in the native porcine adenovirus from which the recombinant porcine adenovirus is produced.
[0048] Preferred vector candidates for use in the recombinant vaccine are PAV isolates of serotype 3 and 4. Use of other serotypes is possible, depending on herd existing immunity and its environment
[0049] The vaccine may be directed against respiratory and intestinal infections caused by a variety of agents. In order to direct the vaccine against a specific infectious organism, heterologous gene sequences encoding the antigenic determinants of those infectious organisms may be incorporated into non-essential regions of the genome of the porcine adenovirus comprising the vector. If the vaccine is to be used to optimise protection against disease, suitable heterologous nucleotide sequences may be those of immuno-potentiators such as cytokines or growth promoters.
[0050] The vaccine may comprise other constituents, such as stabilisers, excipients, other pharmaceutically acceptable compounds or any other antigen or part thereof. The vaccine may be in the form of a lyophilised preparation or as a suspension, all of which are common in the field of vaccine production.
[0051] A suitable carrier for such as a vaccine may be isotonic buffered saline.
[0052] In a further aspect of the invention, there is provided a method of preparing a vaccine for generation and/or optimisation of antibodies or cell-mediated immunity so as to induce or enhance protection against an infectious organism in a pig, which includes constructing a recombinant porcine adenovirus vector stably incorporating at least one heterologous nucleotide sequence, and placing said recombinant porcine adenovirus vector in a form suitable for administration. Preferably the nucleotide sequence is capable of expression as an antigenic polypeptide although it may also be an immuno-potentiator molecule. More preferably, the nucleotide sequence may encode for and/or express, an antigenic polypeptide and an immuno-potentiator molecule. The nucleotide sequence is conveniently foreign to the host vector.
[0053] Even more preferably, the nucleotide sequence is associated with promoter/leader and poly A sequences.
[0054] The form of administration may be that of an enteric coated dosage unit, an inoculum for intra-peritoneal, intramuscular or subcutaneous administration, an aerosol spray, by oral or intranasal application. Administration in the drinking water or in feed pellets is also possible.
[0055] In another aspect of the invention, there is provided a method of producing a porcine adenovirus vaccine vector which includes inserting into a porcine adenovirus at least one heterologous nucleotide sequence. Said heterologous nucleotide sequence is preferably capable of expression as an antigenic polypeptide although it may also be an immuno-potentiator molecule. More preferably, the nucleotide sequence may encode for and/or express, an antigenic polypeptide and an immuno-potentiator molecule.
[0056] Preferably the antigenic polypeptide encoded by the at least one nucleotide sequence is foreign to the host vector.
[0057] More preferably, the heterologous nucleotide sequence is associated with promoter/leader and poly A sequences.
[0058] In one method of construction of a suitable vector the non-essential region to be altered to incorporate foreign DNA could be constructed via homologous recombination. By this method the non-essential region is cloned and foreign DNA together with promoter, leader and poly adenylation sequences is inserted preferably by homologous recombination between flanking sequences. By this method also, deletion of portions of the non-essential region is possible to create extra room for larger DNA inserts that are beyond the normal packing constraints of the virus.
[0059] By this method a DNA expression cassette containing an appropriate PAV promoter with foreign gene sequence as well as leader sequences and poly adenylaton recognition sequences can be constructed with the unique restriction enzyme sites flanking the cassette enabling easy insertion into the PAV genome.
[0060] In another aspect of the invention there is provided strategies for administration of the vaccines of the invention.
[0061] In one strategy, a heterologous antigen and immuno-modulatory molecule such as a cytokine may be expressed in the same recombinant and delivered as a single vaccine.
[0062] In one strategy according to the invention PAV vector based vaccines may be administered as ‘cocktails’ comprising 2 or more virus vectors carrying different foreign genes or immuno-potentiators.
[0063] In a preferred vaccination strategy of the invention, the ‘cocktail’ or simultaneous strategy, a vaccine based on both PAV serotype 3 and serotype 4 is used.
[0064] In another preferred strategy, a base recombinant serotype 3 porcine adenovirus is constructed and the fiber gene from serotype 4 replacing that of serotype 3 or the fiber from serotype 4 additionally cloned into the vaccine to broaden the targeting of the invention to both gut and respiratory delivery.
[0065] In an alternative strategy according to the invention, PAV vector based vaccines may be administered consecutively of each other to either administer booster vaccines or new vaccines at some stage subsequent to initial PAV vaccination. The vaccines used are preferably based on heterologous PAV isolates.
[0066] In a preferred version of the “consecutive” strategy, vaccines based on isolates serotypically unrelated are selected so as to achieve maximum protection against infection. In one example of such a strategy a vaccine based on PAV serotype 3 is administered subsequently or prior to vaccination with a vaccine based on PAV serotype 4.
[0067] Pigs are conveniently inoculated with vector vaccines according to the invention at any age. Piglets may be vaccinated at 1 day old, breeders may be vaccinated regularly up to point of giving birth and thereafter.
[0068] Preferably according to either the consecutive strategy or the cocktail strategy, pigs are vaccinated while still not fully immunocompetent. More conveniently, day-old pigs can be vaccinated for protection against re-infection after a period of 4 weeks subsequent to initial vaccination.
[0069] In a further embodiment of the invention there is provided a method for producing an immune response in a pig including administering to the pig an effective amount of a recombinant vaccine according to the invention. An effective amount is an amount sufficient to elicit an immune response, preferably at least 10 4 TCID 50 per dose.
[0070] The vaccine of the invention may of course be combined with vaccines against other viruses or organisms such as parvovirus or Aujesky's disease at the time of its administration.
[0071] In a preferred aspect of this embodiment of the invention, administration is by oral delivery or intra-nasally.
[0072] Methods for construction and testing of recombinant vectors and vaccines according to this invention will be well known to those skilled in the art. Standard procedures for endonuclease digestion, ligation and electrophoresis were carried out in accordance with the manufacturer's or suppliers instructions. Standard techniques are not described in detail and will be well understood by persons skilled in the art.
BRIEF DESCRIPTION OF THE DRAWINGS
[0073] FIG. 1 illustrates the DNA restriction endonuclease map of the entire PAV serotype 3 genome.
[0074] FIG. 2 illustrates the sequence characterisation and cloning of the major later promoter and splice leader sequences of PAV serotype 3. The sequence is SEQ ID NO:1.
[0075] FIG. 3 illustrates the sequences of the major later promoter, upstream enhancer sequence and splice leaders 1, 2 and 3. The 5′ (upstream) sequence included in the long cassette=SEQ ID NO:2; the sequence including the USF, TATA motif and sequence to the cap site=SEQ ID NO:3; the first leader sequence=SEQ ID NO:4; the second leader sequence=SEQ ID NO:5; the third leader sequence=SEQ ID NO:6.
[0076] FIG. 4 illustrates the terminal 720 bases of the right end of the genome (SEQ ID NO:7).
[0077] FIG. 5 illustrates the promoter region of E3 and the overlapping L4 area.
[0078] FIG. 6 illustrates a preferred method of construction of a PAV vector.
[0079] FIG. 7 represents temperature data of pigs vaccinated with a PAV based vaccine following challenge with CSFV antigen.
[0080] FIG. 8 graphically represents anti-PAV antibody levels detected by ELISA in pigs pre and post vaccination with a PAV based vaccine.
[0081] FIG. 9 graphically illustrates the development of neutralising antibodies in pigs vaccinated with a PAV based vaccine pre and post challenge with CSFV antigen.
[0082] FIG. 10 graphically illustrates the mean white blood cell (WBC) counts of pigs vaccinated with a recombinant PAV vaccine expressing porcine G-CSF.
[0083] FIG. 11 graphically illustrates the percentage change in white blood cell (WBC) counts following vaccination with a recombinant PAV vaccine expressing porcine G-CSF.
[0084] FIG. 12 graphically represents the percentage change in monocyte cell populations following vaccination with recombinant PAV-G-CSF.
[0085] FIG. 13 graphically represents the percentage change in lymphocyte cell populations following vaccination with recombinant PAV-G-CSF.
[0086] FIG. 14 graphically represents the change in stimulation of T-cells following vaccination with recombinant PAV-G-CSF.
[0087] FIGS. 15 a, b and c graphically illustrate a method of construction of a PAV E3 vector.
PREFERRED EMBODIMENTS
[0088] Aspects of preferred embodiments of the invention based on PAV isolates serotype 3 and serotype 4 will now be described. Whilst these two isolates have been selected because of their sites of infection in the pig, it will be appreciated that other isolates of porcine adenovirus may be more suitable for construction of vaccine vectors provided the criteria for selection described herein before are met.
[0089] In general, PAV are considered of low pathogenicity with little consequence in the field. The pathogenic significance of PAV is reviewed in Derbyshire, 1989. The first report of isolation of PAV was from a 12 day old pig with diarrhoea (Haig et al., 1964). Two years later, PAV type 4 was first reported, isolated from the brain of a pig suffering from encephalitis of unknown cause (Kasza, 1966). Later reports have associated PAV mainly with diarrhoea in the field although this is normally low grade. PAV can also be regularly isolated from healthy animals with no disease signs and it is quite likely that its isolation from diseased animals is more a coincidence of its prevalence than an indicator of pathogenicity. However, an association between serotype 4 and respiratory disease has been reported (Watt, 1978) and this has been supported by experimental infection (Edington et al, 1972). Experimental infections with gastrointestinal serotypes of the virus (eg serotype 3) have been able to produce diarrhoea but the pathological changes produced were not clinically significant.
[0090] The genome of the selected PAV serotype 3 was characterised by conventional methods. The DNA restriction endonuclease maps of the entire genome is illustrated in FIG. 1 . The genomes are orientated left to right. By convention adenovirus genomes are normally orientated such that the terminal region from which no late mRNA transcripts are synthesised is located at the left end. The enzymes used to generate the map are indicated at the edge of each map.
[0091] Characterisation of Major Late Promoter (MLP) and Splice Leader Sequences (LS) of PAV Serotype 3
[0092] Identification and Cloning of the PAV MLP
[0093] By use of restriction enzyme and genetic maps of the PAV serotype 3 genome, a region was located that contained the MLP and leader sequences ( FIG. 1 ). The fragments identified in this region were cloned into plasmid vectors and sequenced.
[0094] The MLP promoter sequence was identified as containing a classical TATA sequence, the only one in the region sequenced, as well as upstream factors and was subsequently confirmed by the location of the leader sequence and the transcriptional start site.
[0095] FIGS. 2 and 3 illustrate the sequence characterisation of the major late promoter and splice leader sequences of PAV serotype 3.
[0096] In order to determine the structure and sequence of the leader sequence spliced to late mRNA, porcine kidney cells were infected with PAV and the infection was allowed to proceed until late in the infection cycle (usually 20-24 hr p.i.). At this time total RNA was purified from the infected cells using the RNAgents total RNA purification kit (Promega). The isolated RNA was precipitated with isopropanol and stored at −70° C. in 200 μl aliquots until required. Poly A (mRNA) was isolated from total RNA by the use of the Poly AT tract System (Promega, USA). The isolated mRNA was used in cDNA production.
[0097] For cDNA production, oligonucleotides were produced to the complimentary strand of the hexon gene and the penton base gene, both being MLP transcripts. A further oligonucleotide was produced which covered the proposed cap site of the major late transcript, 24 bases downstream of the TATA box. This oligonucleotide was used in conjunction with that used in cDNA production in Taq polymerase chain reaction. The resulting DNA produced from positive clones was digested with appropriate restriction enzymes to determine the size of the inserted fragment. DNA sequencing of these inserted fragments was performed using a modification of the chain termination technique (Sanger, F., Nicklen, S and Gulson, A. R., 1977, DNA sequencing with chain terminating inhibitors. PNAS USA 74: 5463-5467) so as to allow Taq DNA polymerase extension (Promega, USA).
[0098] To confirm the leader sequence cap site, fresh cDNA was prepared and this time a tail of dGTP residues added to it. Briefly, cDNA was incubated with 1 mM dGTP and approximately 15 units of terminal deoxynucleotidyl transferase (Promega) in 2 mM CaCl2 buffer at 37° C. for 60 minutes. The reaction was stopped by heating to 70° C. for 10 minutes. The DNA was then ethanol precipitated and resuspended in a volume suitable for use in polymerase chain reaction (PCR). PCR was performed as previously described using a poly (dC) oligonucleotide with a XbaI site at the 5′ end. Resulting fragments were blunt ended with T4 DNA polymerase at 37° C. for 30 minutes in the presence of excess nucleotides and cloned into the SmaI site of the pUC18 vector. DNA preparation and sequencing were performed, as described previously, on clones shown to be positive by hybridisation.
[0099] FIG. 3 illustrates the separate sequences of the major late promoter, upstream enhancer sequence and splice leaders 1, 2 and 3 as determined from cDNA studies. FIG. 2 illustrates the DNA sequence of the complete promoter cassette with the components joined together.
[0100] Characterisation of Non-Essential Regions of Viral Genome
[0101] The right end was identified by cloning and complete sequencing of the PAV serotype 3 ApaI fragment J of approximately 1.8 Kbp. The inverted terminal repeat (ITR) has been determined by comparison of the RHE sequence with that of the left hand end. The ITR is 144 bases long and represents the starting point into which potential insertions can be made. FIG. 4 shows the sequence of the terminal 720 bases. Restriction endonuclease sites of interest for insertion of foreign DNA are indicated in the terminal sequence. A putative TATA site for the E4 promoter is identified, this being the left most end for the possible site of insertion. Initial insertions will be made into the SmaI or EcoRI sites.
[0102] The E3 region of the genome, this also being a non-essential area, has been located and cloned. The promoter region of E3 has been identified and the overlapping L4 area sequenced ( FIG. 5 ). The region of the E3 after the polyadenylation signal of the L4 is also a possible site for insertion and can also be used for deletion to create more room for larger cassette insertions.
[0103] Construction of PAV Vector
[0104] FIG. 6 illustrates a preferred method of construction of a PAV vector. The right hand end ApaI fragment J of PAV serotype 3 is cloned and a unique SmaI restriction endonuclease site 230 bp from the inverted repeats was used as an insertion site.
[0105] The major late promoter expression cassette containing the E2 (gp55) gene of classical swine fever virus (hog cholera virus) was cloned into the SmaI site of the RHE fragment.
[0106] A preferred method of homologous recombination was cutting genomic PAV 3 DNA with HpaI, a unique site in the genome, and transfecting this DNA with ApaI cut expression cassette plasmid containing gp55.
[0107] The DNA mix was transfected into preferably primary pig kidney cells by standard calcium chloride precipitation techniques.
[0108] The preferred method of transfection generates recombinant virus through homologous recombination between genomic PAV 3 and plasmid ( FIG. 6 ).
DETAILED DESCRIPTION OF THE INVENTION
Construction of PAV Vector
[0109] The following examples show the constriction of representative recombinant porcine adenoviruses of this invention. The recombinant viruses were propagated and titred on primary porcine kidney cells.
[0110] 1 Construction of PAV-gp55
[0111] An expression cassette consisting of the porcine adenovirus major late promoter, the classical swine lever virus (CSFV) gene (gp55) and SV 40 polyA was inserted into the SmaI site of the right hand end (MU 97-99.5) of porcine adenovirus serotype 3 and used to generate in porcine primary kidney cells a recombinant PAV 3. The size of the expression cassette was 2.38 kilobase pairs. No deletion of the genomic PAV 3 was made. Mammalian adenoviruses with intermediate genomes (˜36 kb) have been shown to accommodate up to 105% of the wild-type genomic length, and genomes larger than this size are either unpackageable or extremely unstable, frequently undergoing DNA rearrangements (Betts, Prevec and Graham, Journal of Virology 67, 5911-5921 (1993). Packaging capacity and stability of human adenovirus type 5 vectors: Parks and Graham, Journal of Virology, 71, 3293-3298, (1997). A helper dependent system for adenovirus vector production helps define a lower limit for efficient DNA packaging). In this invention, PAV genomic length was 34.8 kb, into which was inserted without any other deletion an expression cassette of 2.38 kb. The resulting genomic DNA length of the recombinant porcine adenovirus of this invention was 106.8%, and therefore exceeded the putative maximum limit for construction of a stable recombinant The recombinant virus was plaque purified three times and passaged stably in primary pig kidney cells. The recombinant was shown to contain gp55 by Southern blot hybridisation. Expression of gp55 was demonstrated by infecting primary PK cell line grown on glass cover slips with the recombinant porcine adenovirus. After 24 hours, immunoflouresencent staining (IF) showed infected cells expressing gp55.
[0112] 2 Construction of Recombinant PAV-G-CSF
[0113] An expression cassette comprising of the porcine adenovirus major late promoter, the gene encoding porcine granulocyte-colony stimulating factor G-CSF) and SV40 polyA was inserted into the SmaI site of the right hand end (MU 97-99.5) of porcine adenovirus serotype 3 and used to generate in porcine primary kidney cells a recombinant PAV 3. The size of the expression cassette was 1.28 kilobase pairs. No deletion of the genomic PAV 3 was made. The recombinant virus was plaque purified two times and passaged stably in primary pig kidney cells. The recombinant was shown to contain G-CSF by Southern blot hybridisation and polymerase chain reaction (PCR). Expression of G-CSF was demonstrated by infecting primary kidney cells with the recombinant PAV-G-CSF. Tissue culture supernatants from the infected primary kidney cells were then electrophoresed in SDS-PAGE gels and transferred to filters. Infected cells expressing G-CSF were detected in a Western blot using a rabbit polyclonal antiserum against porcine G-CSF expressed by purified recombinant E coli.
[0114] 3 Construction of Recombinant PAV-gp55T/GM-CSF
[0115] An expression cassette consisting of the porcine adenovirus major late promoter, a truncated form of the classical swine fever virus gene gp55 fused in frame to the gene encoding either the full length or the mature form of porcine granulocyte/macrophage-colony stimulating factor (GM-CSF) and SV40 polyA was inserted into the SmaI site of the right hand end (MU 97-99.5) of porcine adenovirus serotype 3 and used to generate in porcine primary kidney cells a recombinant PAV 3. The size of the expression cassette was 2.1 kilobase pairs. No deletion of the genomic PAV 3 was made. The recombinant virus was plaque purified two times and shown to contain gp55 and GM-CSF by PCR.
[0116] 4 Construction of Recombinant PAV-gp55/E3
[0117] The insertion vector pJJ408 containing the right hand end ApaI fragment J of the PAV serotype 3 genome (approximately 1.8 kbp), was enlarged to contain the complete Bg1II B fragment comprising 7.2 kbp of the PAV3 right hand end ( FIGS. 15 a and b ). This fragment contains both the right hand end insertion site described previously and the E3 region. The right hand end insertion site was engineered to contain the PAV3 MLP/TPL sequences followed by a multiple cloning site and the SV40 poly A sequence.
[0118] An E3 insertion site was constructed by excising a 622 bp SnaBI/BsrGI fragment within the E3 region of the PAV serotype 3. The MLP/TPL-gp55-Poly A expression cassette was inserted into the SnaBI/BsrGI site ( FIGS. 15 b and c ). This plasmid was used in transfections to produce a recombinant PAV3 containing the MLP/TPL-gp55-poly A cassette inserted in the partially deleted E3 region ( FIG. 15 c ).
[0119] Wild type PAV3 DNA was digested with SnaBI restriction enzyme yielding two fragments of 28.712 kbp and 5.382 kbp. The large left hand fragment which includes the overlap region of the right hand end and the left hand end of the PAV3 genome was gel purified. This fragment was transfected into primary PK cells along with KpnI restricted E3/rhe insertion vector DNA in 3 cm petri dishes to allow homologous recombination to occur between the PAV3 and insertion vector DNA. Using this method, only recombinant virus are recovered.
[0120] Cells were maintained for 5 days at 37° C. and then frozen and thawed twice. Lysate was passaged into fresh primary PK cells and observed for the development of plaques. The recombinant virus was plaqued purified and shown to contain gp55 by PCR.
[0121] Vaccination Strategy
[0122] 1. Vaccination with PAV-gp55
[0123] In this experiment 5-6 week old piglets were used to represent immunocompetent pigs. A group of the piglets (#2, 6 and 7) were vaccinated with recombinant PAV-gp55 administered subcutaneously at a dose of 1×10 7 pfu per piglet. A control group of piglets (#3, 8, 11, 12, 13 and 14) were unvaccinated. No clinical signs were observed (no rise in temperature) in the vaccinated group of piglets (Table 1).
[0000]
TABLE 1
Temperatures of pigs vaccinated with rPAV::gp55
Temperatures of pigs vaccinated with rPAV::gp55
Pig
Day
No.
0
1
2
3
6
9
10
13
2
39.7
39.2
39.4
39.8
39.6
39.8
39.6
39.2
3 (control)
39.5
39.2
39.4
39.0
38.8
39.3
39.0
39.7
6
39.7
39.1
39.1
39.0
39.1
39.8
39.1
39.8
7
39.4
39.8
39.8
39.4
39.9
38.9
39.6
39.7
8 (control)
39.6
39.5
39.4
39.0
40.5
39.4
39.1
39.7
[0124] Five weeks after vaccination with the recombinant PAV-gp55 both groups of pigs were challenged with a lethal dose (1×10 3.5 TCID 50 ) of virulent Hog Cholera virus (Classical swine fever virus) applied subcutaneously.
[0125] The temperatures of the pigs were monitored and the results tabulated in Table 2 and graphically represented in FIG. 7 .
[0000]
TABLE 2
Temperatures post challenge with CSFV (° C.)
Pig
Day
No.
−1
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
2
39.6
39.9
40.1
40.3
40.1
39.2
39.7
39.5
39.5
39.7
39.4
39.1
39.5
39.1
40.0
39.4
38.9
3
39.6
40.4
39.6
40.0
40.7
40.7
41.9
40.7
40.9
42.0+
6
39.5
39.5
40.0
40.0
39.6
40.5
39.9
39.2
39.2
38.8
39.3
38.8
38.9
39.6
39.3
39.1
38.9
7
39.8
39.9
40.4
40.6
40.3
39.7
39.7
39.7
39.5
39.3
39.1
39.3
39.6
40.6
39.7
39.8
39.7
8
39.9
40.6
40.5
40.3
40.0
41.4
39.8
41.0
40.6
39.0+
11
39.6
39.9
40.0
40.3
40.7
40.5
40.0
41.8
41.5
41.3+
12
39.8
39.9
40.9
41.0
41.2
40.6
40.1
41.0
41.7
40.3+
13
39.7
40.0
41.2
41.5
41.6
41.0
39.7+
14
39.3
40.0
39.6
39.8
40.3
40.7
41.2
40.8
40.2
41.7+
[0126] The results show that by day 5 the control group had elevated temperatures (greater than 40.5° C.) and showed clinical signs of disease. The vaccinated group showed no clinical signs of disease. Pigs from the control group were dead or euthanased by day 9. The vaccinated group were euthanased at day 16. At post mortem all control pigs showed severe clinical disease, the vaccinated pigs showed no clinical signs of disease.
[0127] The results indicate that the pigs vaccinated subcutaneously with the recombinant PAV-gp55 survived challenge with classical swine fever virus at a lethal dose.
[0128] Sera were collected from both groups of pigs and tested for the presence of antibodies to PAV by ELISA. These tests showed the presence of pre-existing antibodies to PAV before vaccination. The level of these antibodies increased following vaccination with the recombinant PAV-gp55 to peak between days 28 and 36 post vaccination. These results are tabulated in FIG. 8 .
[0129] Sera were collected from the vaccinated group of pigs pre and post challenge with CSFV and tested in the presence of neutralising antibodies to CSFV. Sera were tested at days 0 and 28 after vaccination with recombinant PAV-gp55 (pre challenge) and then again at day 16 post challenge (day 52 after vaccination). The results in FIG. 9 show no neutralising antibodies detected at day 0, low levels of neutralising antibodies at day 28 and high levels at day 52.
[0130] These results show that the recombinant PAV-gp55 can protect pigs from lethal challenge with classical swine fever virus in the presence of pre-existing antibodies to PAV.
[0131] 2. Vaccination with PAV-G-CSF
[0132] In this experiment 5-6 week old piglets were used to represent immunocompetent pigs. A group of pigs (n=4) were vaccinated with recombinant PAV-G-CSF administered subcutaneously at a dose of 1×10 7 pfu per piglet A second group (n=4) were vaccinated with PAV wild type (wt) administered subcutaneously at a dose of 1×10 7 pfu per piglet. A control group (n=4) were unvaccinated. Pigs were bled at 8 hour intervals for a period or 104 hours post vaccination. Complete blood counts were determined and the mean white blood cell (WBC) counts for each group monitored. These results are graphically represented in FIG. 10 and the percentage change in mean WBC counts graphically represented in FIG. 11 .
[0133] Pigs vaccinated with either PAV wt or PAV-G-CSF showed clinical signs of disease with mild diahorrea 24-72 hours post vaccination. Both groups of pigs were completely recovered by 80-96 hours post-vaccination. Control pigs showed no clinical signs of disease.
[0134] Complete blood screening results show that the mean WBC counts for control pigs increased over the duration of the experiment.
[0135] PAV wt vaccinated pigs also show an increase in WBC counts, with a depression in WBC counts between 48-80 hours post-vaccination and recovery from 80-96 hours onwards.
[0136] Pigs vaccinated with the recombinant PAV-G-CSF show a significant depression in WBC counts over the duration of the experiment. A statistical analysis of these results is tabulated in Table 3. The analysis shows that differences between the mean WBC counts (controls and PAV-G-CSF; PAV wt and PAV-G-CSF) were significant indicating that the recombinant PAV-G-CSF altered the proportions of cells involved with immunity.
[0000]
TABLE 3
Results of t-tests between mean WBC counts of groups of pigs
vaccinated with either PAV wild type (wt), PAV recombinant
expressing G-CSF (PAV-G-CSF) or unvaccinated controls.
Pre vacc
0 hr
8-24 hr d
32-48 hr
56-72 hr
80-104 hr
Control vs PAV-G-CSF a
p > 0.2 b
P > 0.2
P > 0.2
P > 0.2
P < 0.005
Control vs PAV wt
p > 0.1
p > 0.01 c
p > 0.02
p > 0.2
P < 0.05
PAT-G-CSF vs PAV wt
p > 0.2
p > 0.05
p > 0.05
P < 0.05
P < 0.001
a null hypothesis; there is no difference between the mean WBC counts.
b p > 0.05, insufficient to reject the null hypotheses at the 95% confidence level, conclude that there is no difference between mean leucocyte levels.
c p < 0.05, null hypothesis rejected at 95% confidence level, conclude that there is a difference between the mean leucocyte levels.
d 4 pigs in each group were bled at 8 hour intervals.
[0137] Differential WBC counts were also determined and monitored for each group. The percentage change in mean monocyte cell populations graphically represented in FIG. 12 and the percentage change in mean lymphocyte cell populations graphically represented in FIG. 13 . FIG. 12 shows that monocyte cell populations increased rapidly in pigs following vaccination with PAV wt, but were suppressed by vaccination with the recombinant PAV-G-CSF. This effect was due to the expression of G-CSF by the recombinant. A statistical analysis of these results is tabulated in Table 4. The analysis shows that there was a significant difference between the PAV wt and PAV-G-CSF from 32 to 96 hours post vaccination. FIG. 13 shows that there were shifts in lymphocyte cell population numbers following vaccination with the recombinant PAV-G-CSF. Unvaccinated controls show stable lymphocyte cell numbers over the duration of the experiment, whereas pigs vaccinated with PAV wt show a significant increase in lymphocyte cell population as a response to infection. Pigs vaccinated with the recombinant PAV-G-CSF show a decline in lymphocyte cell population. A statistical analysis of these results is tabulated in Table 5. The analysis shows that there was a significant difference between PAV wt and the recombinant PAV-G-CSF between 8 and 96 hours post vaccination. The different responses in lymphocyte cell proliferation following vaccination with recombinant PAV-G-CSF and PAV wt were due to the expression of G-CSF by the recombinant. These results show that vaccination with recombinant PAV-G-CSF produces a shift in sub-populations of cells involved in immunity.
[0000]
TABLE 4
Results of t-tests between mean monocytes cell populations following vaccination of pigs
with either recombinant PAV-G-CSF, wilt type PAV (PAV wt) or unvaccinated controls.
Pre vacc
8-24 hr d
32-48 hr
56-72 hr
80-96 hr
104 hr
Control vs PAV-G-CSF a
p > 0.1 b
P > 0.2
P > 0.2
P > 0.2
P < 0.2
p > 0.2
Control vs PAV wt
p > 0.2
p < 0.002 c
p > 0.2
P < 0.001 c
P > 0.2
p > 0.2
PAV wt vs PAV-G-CSF
p > 0.2
P < 0.001
p > 0.2
P > 0.2
P > 0.2
p > 0.05
a null hypothesis; there is no difference between the mean monocyte cell counts.
b p > 0.1, insufficient to reject the null hypothesis at the 90% confidence level, conclude that there is no difference between mean monocyte cell levels.
c p < 0.05, null hypothesis rejected at 95% confidence level, conclude that there is a difference between the mean monocyte cell levels.
d 4 pigs in each group were bled at 8 hour intervals.
[0000]
TABLE 5
Results of t-tests between mean lymphocyte cell populations following vaccination of pigs
with either recombinant PAV-G-CSF, wild type PAV (PAV wt) or unvaccinated controls.
Pre vacc
8-24 hr d
32-48 hr
56-72 hr
80-96 hr
104 hr
Control vs PAV-G-CSF a
p > 0.2
P > 0.05 b
P > 0.2
P > 0.2
P > 0.2
p > 0.2
Control vs PAV wt
p > 0.2
P > 0.2
P < 0.01 c
P < 0.001 c
P < 0.001 c
p > 0.2
PAV wt vs PAV-G-CSF
p > 0.2
P < 0.05 c
P < 0.002 c
P < 0.005 c
P < 0.001 c
p > 0.05
a null hypothesis; there is no difference between the mean lymphocyte cell counts.
b p > 0.05, insufficient to reject the null hypothesis at the 95% confidence level, conclude that there is no difference between mean lymphocyte cell levels.
c p < 0.05, null hypothesis rejected at 95% confidence level, conclude that there is a difference between the mean lymphocyte cell levels.
d 4 pigs in each group were bled at 8 hour intervals.
[0138] FIG. 14 graphically represents changes in the proliferation of T cells of each group following stimulation with Concanavalin A (Con A). These results confirm that there was a significant proliferation of T-cells following vaccination with PAV wt at day 2 post vaccination, whereas vaccination with the recombinant PAV-G-CSF resulted in a suppression of T-cell proliferation by day 3.
[0139] The results of vaccination with a recombinant PAV expressing porcine G-CSF shows that G-CSF has a significant effect on the cells involved with immune responses.
[0140] It will be appreciated that whilst this document establishes the metes and bounds of this invention, all embodiments falling within its scope for example with regard to heterologous genes, insertion sites, types of promoter and senotype have not necessarily been specifically exemplified although it is intended that they should fall within the scope of protection afforded this invention.
[0141]
FIG. 2
[0142] Total Sequence of the PAV Major Late Promoter cassette (SEQ ID NO:1) including the added nucleotides 5′ (upstream) of the USF.
[0000]
Nucleotide base count: 76 A 143 C 187 G 96 T Total 502 bp
1
GGTGCCGCGG TCGTCGGCGT AGAGGATGAG GGCCCAGTCG GAGATGAAGG CACGCGCCCA
61
GGCGAGGACG AAGCTGGCGA CCTGCGAGGG GTAGCGGTCG TTGGGCACTA ATGGCGAGGC
121
CTGCTCGAGC GTGTGGAGAC AGAGGTCCTC GTCGTCCGCG TCCAGGAAGT GGATTGGTCG
181
CCAGTGGTAG TCĊACGTGAC CGGCTTGCGG GTCGGGGGGT ATAAAA GGCG CGGGCCGGGG
241
TGCGTGGCCG TC A GTTGCTT CGCAGGCCTC GTCACCGGAG TCCGCGTCTC CGGCGTCTCG
301
CGCTGCGGCT GCATCTGTGG TCCCGGAGTC TTCA GG TCCT TGTTGAGGAG GTACTCCTGA
361
TCGCTGTCCC AGTACTTGGC GTGTGGGAAG CCGTCCTGAT C GC GATCCTC CTGCTGTTGC
421
AGCGCTTCGG CAAACACGCG CACCTGCTCT TCGGACCCGG CGAAGCGTTC GACGAAGGCG
481
TCTAGCCAGC AACAGTCGCA AG
[0143] The Upstream Stimulatory Factor (USF) and TATA motif are in bold. The complete leader sequence is italised with the cap site and splice sites between the individual leaders indicated by double underlining or single underlining respectively.
[0144]
FIG. 3
[0145] Individual sequences of the Promoter cassette components. The 5′ (upstream) sequence included in the long cassette=SEQ ID NO:2; the sequence including the USF, TATA motif and sequence to the cap site=SEQ ID NO:3; the first leader sequence=SEQ ID NO:4; the second leader sequence=SEQ ID NO:5; the third leader sequence=SEQ ID NO:6.
Individual Sequences of the Promoter Cassette Components:
[0146] I. The 5′ (upstream) sequence included in the long cassette.
[0000] 1 GGTGCCGCGG TCGTCGGCGT AGAGGATGAG GGCCCAGTCG GAGATGAAGG CACGCGCCCA 61 GGCGAGGACG AAGCTGGCGA CCTGCGAGGG GTAGCGGTCG TTGGGCACTA ATGGCGAGGC 121 CTGCTCGAGC GTGTGGAGAC AGAGGTCCTC GTCGTCCGCG TCCAGGAAGT GGATTGGTCG 181 CCAGTGGTAG
II. Sequence including the USF, TATA motif and sequence to the cap site.
[0000] 1 CCACGTGACC GGCTTGCGGG TCGGGGGTA TAAAAGGCGC GGGCCGGGGT GCGTGGCCGT 61 C
III. First leader sequence.
[0000] 1 AGTTGCTTCG CAGGCCTCGT CACCGGAGTC CGCGTCTCCG GCGTCTCGCG CTGCGGCTGC 61 ATCTGTGGTC CCGGAGTCTT CAG
IV. Second leader sequence.
[0000] 1 GTCCTTGTTG AGGAGGTACT CCTGATCGCT GTCCCAGTAC TTGGCGTGTG GGAAGCCGTC 61 CTGATCG
V. Third leader sequence.
[0000]
1
CGATCCTCCT GCTGTTGCAG CGCTTCGGCA AACACGCGCA CCTGCTCTTC GGACCCGGCG
61
AAGCGTTCGA CGAAGGCGTC TAGCCAGCAA CAGTCGCAAG
[0147]
FIG. 4
[0148] FIG. 4 Sequence of the right hand end of the PAV genome this area being a proposed site for insertion of expression cassettes (SEQ ID NO:7).
Nucleotide Base Count 183 A 255 C 306 G 204 T Total 948 Bases
[0149]
[0000]
1
CATCATCAAT AATATACCGC ACACTTTTAT TGCCCCTTTT GTGGCGTGGT GATTGGCGGA
61
GAGGGTTGGG GGCGGCGGGC GGTGATTGGT GGAGAGGGGT GTGACGTAGC GTGGGAACGT
121
GACGTCGCGT GGGAAAATAA CGTGGCGTGG GAACGGTCAA AGTCCGAGGG GCGGGGTCAA
181
AGTCCGCAGT CGCGGGGCGG AGCCGGCTGG CGG GAATTCC CGGG ACTTTC TGGGCGGGTA
EcoRI SmaI
241
AT CGTTAAC G CGGAGGCGGG G GAATTC CGA TCGGACGATG TGGTACTGAT TAACCGACCG
HpaI EcoRI
301
CAGGCGTGTC CACATCCGCT GTGGGTATAT CACCGGCGCT CGCGGTGTTC GCTCACAGTC
361
GTCTCGGCGC TGTCACAGAG AGAGACACTG AGAGCGAGAC GAGGAGAAAC CGAAAGCGGG
421
GCAGGAGGAG TCACCGGGCC ATCTTCCAT CAGAGCCCTC TCATGGCCCA CGACCGACTG
481
CTGCTGGCCG CGGTGGCTGA CTGTTGCTCG CCGTGCTCTA TCTGTACTTC GCCTACCTCG
541
CGTGGCAGGA TCGGGACACT CTTCACACTC AGGAGGCCGC CTCTCCTCGC TTCTTCATCG
601
GGTCCAACCA CCAGCCCTGG TGCCCGGATT TTGATTGGCA GGAGCAGGAC GAGCACACTC
661
ACTAGACGTT TAGAAAAAAG ACACACATTG GAACTCATAT ATGTCTGCGG GACCGCATCA
721
GCAGCCCGGT CTGCTGTTGG CTGCGGGTGA G AGGCCT CCG GTAATTCATC AGAACCGCAT
StuI
781
TCATCTGCGC CACGTCCCGA CATATGGTGC T GACGTC AGA ACAGCCCAGC GTGATCCTTT
SacIII
841
TAATGTGCTA GTCTACGTGC CCACTGGGTT TGCTGTGTTT GTGCCGACTG AGCGAGATTT
901
TCAGAGGAGG GATCTGGTCC GTTCCAGAC CTGCTGCTTC CGGCATCA
[0150] The Inverted Terminal Repeat (ITR) is shown in bold. Enzyme sites of interest are underlined with the enzyme name below. Putative TATA for E4 region is also shown. | This invention relates to a recombinant vector including a recombinant porcine adenovirus, stably incorporating and capable of expression of at least one heterologous nucleotide sequence. The nucleotide sequence is preferably one which encodes an antigenic determinant of Hog Cholera Virus or Pseudorabies virus. The further invention relates to a method of production of recombinant vectors, to methods of preparation of vaccines based on the vectors, to administration strategies and to methods of protecting pigs from disease. | 2 |
RELATED APPLICATIONS AND PRIORITY
[0001] THIS APPLICATION is a continuation in part of and therefore entitled to the filing date of copending U.S. patent application Ser. No. 08/716,672 titled “Twisting Cylinder Display” filed Sep. 13, 1996 which claimed priority from the following U.S. provisional applications having the same assignee and at least one common inventor: No. 60/020,651, filed Jun. 27, 1996; and No. 60/020,522, also filed Jun. 27, 1996.
INCORPORATION BY REFERENCE
[0002] The following U.S. patents are fully incorporated herein by reference: U.S. Pat. No. 4,126,854, (Sheridon, “TWISTING BALL PANEL DISPLAY”); U.S. Pat. No. 4,143,103 (Sheridon, “METHOD OF MAKING A TWISTING BALL PANEL DISPLAY”); U.S. Pat. No. 5,262,098 (Crowley et al., “METHOD AND APPARATUS FOR FABRICATING BICHROMAL BALLS FOR A TWISTING BALL DISPLAY”); U.S. Pat. No. 5,344,594 (Sheridon, “METHOD FOR THE FABRICATION OF MULTICOLORED BALLS FOR A TWISTING BALL DISPLAY”); and U.S. Pat. No. 5 , 389 , 945 (Sheridon, “WRITING SYSTEM INCLUDING PAPER-LIKE DIGITALLY ADDRESSED MEDIA AND ADDRESSING DEVICE THEREFOR”), U.S. patent application Ser. No. 08/572,779 (Attorney Docket No. D/95115), entitled “POLYCHROMAL SEGMENTED BALLS FOR A TWISTING BALL DISPLAY”; U.S. patent application Ser. No. 08/572,778 (Attorney Docket No. D/95115Q1), entitled “APPLICATIONS OF A TRANSMISSIVE TWISTING BALL DISPLAY”; U.S. patent application Ser. No. 08/572,819 (Attorney Docket No. D/95115Q2), entitled “CANTED ELECTRIC FIELDS FOR ADDRESSING A TWISTING BALL DISPLAY”; U.S. patent application Ser. No. 08/572,927 (Attorney Docket No. D/95115Q3), entitled “HIGHLIGHT COLOR TWISTING BALL DISPLAY”; U.S. patent application Ser. No. 08/572,912 (Attorney Docket No. D/95115Q4), entitled “PSEUDO-FOUR COLOR TWISTING BALL DISPLAY”; U.S. patent application Ser. No. 08/572,820 (Attorney Docket No. D/95116), entitled “ADDITIVE COLOR TRANSMISSIVE TWISTING BALL DISPLAY”; U.S. patent application Ser. No. 08/572,780 (Attorney Docket No. D/95116Q1), entitled “SUBTRACTIVE COLOR TWISTING BALL DISPLAY”; U.S. patent application Ser. No. 08/572,775 (Attorney Docket No. D/95116Q2), entitled “MULTITHRESHOLD ADDRESSING OF A TWISTING BALL DISPLAY”; U.S. patent application Ser. No. 08/572,777 (Attorney Docket No. D/95116Q3), entitled “FABRICATION OF A TWISTING BALL DISPLAY HAVING TWO OR MORE DIFFERENT KINDS OF BALLS”; and U.S. patent application Ser. No. 08/573,922 (Attorney Docket No. D/95271), entitled “ADDITIVE COLOR TRISTATE LIGHT VALVE TWISTING BALL DISPLAY.” All filed concurrently on Dec. 15, 1995, and two divisional applications from U.S. patent application Ser. No. 08/572,779 (Attorney Docket No. D/95115), entitled “POLYCHROMAL SEGMENTED BALLS FOR A TWISTING BALL DISPLAY”, “POLYCHROMAL SEGMENTED BALLS FOR A TWISTING BALL DISPLAY”(Attorney Docket No. D/95115D1) now U.S. Pat. No. A,AAA,AAA, U.S. patent application Ser. No. 08/BBB,BBB (Attorney Docket No. D/95115D2), entitled “APPARATUS FOR FABRICATING POLYCHROMAL SEGMENTED BALLS FOR A TWISTING BALL DISPLAY” filed on Jul. 10, 1997
RELATED PATENT APPLICATIONS
[0003] The following copending, coassigned U.S. patent applications are related to this case: U.S. patent application Ser. No. 08/713935 (Attorney Docket No. D/96129), entitled “MONOLAYER GYRICON DISPLAY”; U.S. patent application Ser. No. 08/713,936 (Attorney Docket No. D/96129Q1), entitled “HIGH REFLECTANCE GYRICON DISPLAY”; U.S. patent application Ser. No. 08/716,675 (Attorney Docket No. D/96129Q2), entitled “GYRICON DISPLAY WITH INTERSTITIALLY PACKED PARTICLE ARRAYS”; and U.S. patent application Ser. No. 08/713,325 (Attorney Docket No. D/96129Q3), entitled “GYRICON DISPLAY WITH NO ELASTOMER SUBSTRATE.”
BACKGROUND OF THE INVENTION
[0004] The invention pertains to visual displays and more particularly to twisting-ball displays, such as gyricon displays and the like.
[0005] Gyricon displays, also known by other names such as electrical twisting-ball displays or rotary ball displays, were first developed over twenty years ago. See U.S. Pat. Nos. 4,126,854 and 4,143,103, incorporated by reference hereinabove.
[0006] An exemplary gyricon display 10 is shown in side view in FIG. 1A (PRIOR ART). Bichromal balls 1 are disposed in an elastomer substrate 2 that is swelled by a dielectric fluid creating cavities 3 in which the balls 1 are free to rotate. The balls 1 are electrically dipolar in the presence of the fluid and so are subject to rotation upon application of an electric field, as by matrix-addressable electrodes 4 a , 4 b . The electrode 4 a closest to upper surface 5 is preferably transparent. An observer at I sees an image formed by the black and white pattern of the balls 1 as rotated to expose their black or white faces (hemispheres) to the upper surface 5 of substrate 2 .
[0007] A single one of bichromal balls 1 , with black and white hemispheres 1 a and 1 b , is shown in FIG. 1B (PRIOR ART).
[0008] Gyricon displays have numerous advantages over conventional electrically addressable visual displays, such as LCD and CRT displays. In particular, they are suitable for viewing in ambient light, retain an image indefinitely in the absence of an applied electric field, and can be made lightweight, flexible, foldable, and with many other familiar and useful characteristics of ordinary writing paper. Thus, at least in principle, they are suitable both for display applications and for so-called electric paper or interactive paper applications, in which they serve as an electrically addressable, reuseable (and thus environmentally friendly) substitute for ordinary paper. For further advantages of the gyricon, see U.S. Pat. No. 5,389,945, incorporated by reference hereinabove.
[0009] Known gyricon displays employ spherical particles (e.g., bichromal balls) as their fundamental display elements. There are good reasons for using spherical particles. In particular:
[0010] Spherical bichromal balls can be readily manufactured by a number of techniques. See the '098 and '594 patents, incorporated by reference hereinabove, in this regard.
[0011] Spheres are symmetrical in three dimensions. This means that fabrication of a gyricon display sheet from spherical particles is straightforward. It is only necessary to disperse the balls throughout an elastomer substrate, which is then swelled with dielectric fluid to form spherical cavities around the balls. The spherical balls can be placed anywhere within the substrate, and at any orientation with respect to each other and with respect to the substrate surface. There is no need to align the balls with one another or with the substrate surface. Once in place, a ball is free to rotate about any axis within its cavity.
[0012] “In the ‘white’ state, the gyricon display reflects almost entirely from the topmost layer of bichromal balls and, more particularly, from the white hemispherical upper surfaces of the topmost layer of balls. In a preferred embodiment, the inventive display is constructed with a single close-packed monolayer of bichromal balls.”
[0013] Ideally, a close-packing arrangement would entirely cover the plane with the monolayer of gyricon elements. However,. Inasmuch as a planar array of spheres cannot fully cover the plane, but must necessarily contain interstices, the best that can be achieved with a single population of uniform-diameter spherical elements is about 90.7 percent areal coverage, which is obtained with a hexagonal packing geometry. A second population of smaller balls can be added to fill in the gaps somewhat, but this complicates display fabrication and results in a tradeoff between light losses due to unfilled interstices and light losses due to absorption by the black hemispheres of the smaller interstitial balls.
[0014] Therefore, it would be desirable to provide a close-packed monolayer gyricon display in which areal coverage surpasses 90.7 percent or approaches 100 percent, without any need for interstitial particles. This can be done by using cylindrical rather than spherical elements. For example, a rectangular planar monolayer array of cylinders can be constructed that entirely or almost entirely covers the plane. With the white faces of the cylinders exposed to an observer, little if any light can get through the layer.
SUMMARY OF THE INVENTION
[0015] The invention provides a gyricon display having cylindrical, rather than spherical, rotating elements. The elements can be bichromal or polychromal cylinders, preferably aligned parallel to one another and packed close together in a monolayer. The close-packed monolayer configuration provides excellent brightness characteristics and relative ease of manufacture as compared with certain other high-brightness gyricon displays. The cylinders can be fabricated by techniques that will be disclosed. The substrate containing the cylinders can be fabricated with the swelled-elastomer techniques known from spherical-particle gyricon displays, with a simple agitation process step being used to align the cylinders within the sheeting material.
[0016] Further, the invention is well-suited to providing a gyricon display having superior reflectance characteristics comparing favorably with those of white paper. A gyricon display is made with a close-packed monolayer of cylinders, wherein cylinders are placed, preferably in a rectangular packing arrangement, so that the surfaces of adjacent cylinders are as close to one another as possible. The light reflected from the inventive gyricon display is reflected substantially entirely from the monolayer of cylinders, so that lower layers are not needed. The areal coverage fraction obtainable with cylinders is greater than that obtainable with a single monolayer of uniform-diameter spheres.
[0017] In one aspect, the invention provides a material comprising a substrate and a plurality of nonspheroidal (e.g., substantially cylindrical) optically anisotropic particles disposed in the substrate. A rotatable disposition of each particle is achievable while the particle is thus disposed in the substrate; for example, the particles can already be rotatable in the substrate, or can be rendered rotatable in the substrate by a nondestructive operation performed on the substrate. In particular, the substrate can be made up of an elastomer that is expanded by application of a fluid thereto so as to render the particles rotatable therein. A particle, when in its rotatable disposition, is not attached to the substrate. A display apparatus can be constructed from a piece of the material together with means (such as an electrode assembly) for facilitating a rotation of at least one particle rotatably disposed in the substrate of the piece of material.
[0018] In another aspect, the invention provides a material comprising a substrate having a surface and a plurality of nonspheroidal optically anisotropic particles disposed in the substrate substantially in a single layer. The particles (e.g., cylinders) are of a substantially uniform size characterized by a linear dimension d (e.g., diameter). Each particle has a center point, and each pair of nearest neighboring particles in the layer is characterized by an average distance D therebetween, the distance D being measured between particle center points. A rotatable disposition of each particle is achievable while the particle is thus disposed in the substrate. A particle, when in its rotatable disposition, is not attached to the substrate. Particles are sufficiently closely packed with respect to one another in the layer such that the ratio of the union of the projected areas of the particles to the area of the substrate surface exceeds the areal coverage fraction that would be obtained from a comparably situated layer of spheres of diameter d disposed in a hexagonal packing arrangement with an average distance D therebetween as measured between sphere centers. If the ratio Dld is made as close to 1.0 as practicable, the ratio of the union of the projected areas of the particles to the area of the substrate surface can be made to exceed the maximum theoretically possible areal coverage fraction for a maximally close-packed hexagonal packing geometry of a layer of spheres of diameter d, which is approximately equal to 90.7 percent.
[0019] The invention will be better understood with reference to the following description and accompanying drawings, in which like reference numerals denote like elements.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] [0020]FIG. 1A is an exemplary gyricon display of the PRIOR ART, incorporating bichromal balls;
[0021] [0021]FIG. 1B illustrates a spherical bichromal ball of the PRIOR ART.
[0022] [0022]FIG. 2 illustrates a bichromal cylinder, showing in particular the diameter and height thereof.
[0023] [0023]FIG. 3 illustrates bichromal cylinders in cavities in an elastomer substrate.
[0024] [0024]FIG. 4 illustrates bichromal cylinders arrayed in an ideal close-packed monolayer.
[0025] FIGS. 5 A- 5 B are, respectively, side and top views of a gyricon display of the present invention in an embodiment wherein bichromal cylinders of unit (1:1) aspect ratio are arrayed in a monolayer configuration.
[0026] [0026]FIG. 6 is a side view of a gyricon display of the present invention in an alternative embodiment wherein the bichromal cylinders are arrayed in a multilayer configuration, with relatively large cavity size.
[0027] FIGS. 7 - 8 illustrate top views of gyricon displays of the present invention in alternative embodiments in which the cylinders are, respectively, staggered in their alignment or randomly oriented.
[0028] [0028]FIG. 9 illustrates a top views of gyricon display of the present invention in an alternative embodiment in which the cylinder aspect ratio is greater than 1:1.
[0029] [0029]FIG. 10 illustrates a side view of a spinning-disk mechanism for fabrication of bichromal balls in the PRIOR ART.
[0030] [0030]FIG. 11 illustrates a top view of a spinning-disk mechanism for fabrication of bichromal cylinders of the invention.
[0031] [0031]FIG. 12 illustrates an alternative embodiment of the gyricon display of the invention wherein there is no elastomer or other cavity-containing substrate to retain the monolayer of cylinders in place.
[0032] [0032]FIG. 13A illustrates a polychromal sphere with three display states.
[0033] [0033]FIG. 13B illustrates a polychromal cylinder with three display states.
[0034] [0034]FIG. 13C illustrates an alternative embodiment of a polychromal cylinder with three display states.
[0035] [0035]FIG. 14A illustrates a polychromal sphere for use in a pseudo four color gyricon.
[0036] [0036]FIG. 14B illustrates a polychromal cylinder for use in a pseudo four color gyricon.
[0037] [0037]FIG. 15A illustrates a sphere for use in a full color gyricon or as a light valve.
[0038] [0038]FIG. 15B illustrates a cylinder for use in a full color gyricon device or as a light valve.
[0039] [0039]FIG. 16A illustrates an alternative sphere for use in a gyricon device as a light valve.
[0040] [0040]FIG. 16B illustrates an alternative cylinder for use in a gyricon device as a light valve.
[0041] [0041]FIG. 17A illustrates a multiple-disk assembly for fabricating multichromal gyricon balls.
[0042] [0042]FIG. 17B illustrates a portion of the multiple-disk assembly shown in FIG. 17A.
[0043] [0043]FIG. 17C illustrates a side view of multichromal gyricon ball made using the disk assembly shown in FIGS. 17 A-B.
[0044] [0044]FIG. 17D illustrates a top view of multichromal gyricon ball made using the disk assembly shown in FIGS. 17 A-B
[0045] [0045]FIG. 18 illustrates a top view of a spinning-disk mechanism for fabrication of polychromal cylinders of the invention.
DETAILED DESCRIPTION
[0046] In a preferred embodiment of the invention, bichromal cylinders are arranged in a close-packed planar monolayer, as close to one another as possible, so as to cover the plane of the monolayer. The advantages of a close-packed monolayer display are discussed at length in copending, coassigned U.S. patent application Ser. No. 08/713,935 (Attorney Docket No. D/96129), entitled “Monolayer Gyricon Displays”; suffice it to say here that close-packed monolayer displays exhibit superior reflectance and brightness characteristics as compared with conventional gyricon displays, and that the more of the monolayer plane that is covered by the gyricon elements, the better the reflectance and the brighter the display.
[0047] To quote briefly from Ser. No. 08/713,935: “In the ‘white’ state, the inventive display reflects entirely from the topmost layer of bichromal balls and, more particularly, from the white hemispherical upper surfaces of the topmost layer of balls. In a preferred embodiment, the inventive display is constructed with a single close-packed monolayer of bichromal balls.”
[0048] Ideally, a close-packing arrangement according to Ser. No. 08/713,935 would entirely cover the plane with the monolayer of gyricon elements. However, the displays disclosed in Ser. No. 08/713,935 are all based on spherical balls of the prior art. In as much as a planar array of spheres cannot fully cover the plane, but must necessarily contain interstices, the best that can be achieved with a single population of uniform-diameter spherical elements is about 90.7 percent areal coverage, which is obtained with a hexagonal packing geometry. A second population of smaller balls can be added to fill in the gaps somewhat, but this complicates display fabrication and results in a tradeoff between light losses due to unfilled interstices and light losses due to absorption by the black hemispheres of the smaller interstitial balls.
[0049] The present invention provides a close-packed monolayer gyricon display in which areal coverage can approach 100 percent, without any need for interstitial particles. It does so by using cylindrical rather than spherical bichromal elements. For example, a rectangular planar monolayer array of cylinders can be constructed that entirely or almost entirely covers the plane. With the white faces of the cylinders exposed to an observer, little if any light can get through the layer.
[0050] [0050]FIG. 2 illustrates a bichromal cylinder 20 suitable for use as a rotating element of the inventive gyricon display. Cylinder 20 has white face 21 and black face 22 . Cylinder 20 is of height (or length) h and has diameter d. The aspect ratio of cylinder 20 is defined herein as the ratio h/d. In the presence of a dielectric fluid, cylinder 20 is electrically dipolar, with the dipole moment preferably oriented perpendicular to the plane separating the white and black portions of the cylinder and passing perpendicularly through the longitudinal axis of the cylinder.
[0051] [0051]FIG. 3 illustrates how bichromal cylinders can be arranged in an elastomer substrate for use in the inventive display. A portion of a gyricon display 30 is shown. In display 30 , bichromal cylinders 31 are disposed in an elastomer substrate 32 that is swelled by a dielectric fluid (not shown) creating cavities 33 in which the cylinders 31 are free to rotate about their respective longitudinal axes. Cavities 33 are preferably not much larger in diameter than cylinders 31 , so that cylinders 31 are constrained from rotating about their medial axes. Cylinders 31 are electrically dipolar in the presence of the dielectric fluid, and so are subject to rotation upon application of an electric field. As shown, cylinders 31 can be rotated so as to expose either their white or black faces to an observer at I.
[0052] [0052]FIG. 4 illustrates bichromal cylinders arrayed in a close-packed monolayer. A portion of a gyricon display 40 includes rows of bichromal cylinders 41 a and 41 b of uniform diameter. Cylinders 41 a , 41 b are disposed in a monolayer between the upper and lower surfaces 44 a , 44 b of display 40 . Preferably there is exactly one cylinder between any given point on upper surface 44 a and the corresponding point directly beneath it on lower surface 44 b.
[0053] The white faces of cylinders 41 a , 41 b are shown turned towards transparent viewing surface 44 a . In this configuration, light from a light source L incident on upper surface 44 a is scattered by the white faces of cylinders 41 a , 41 b and is reflected so as to be visible to an observer at I. Thus display 40 appears white to the observer.
[0054] As shown, the cylinders are aligned end-to-end within the monolayer, the circular ends of cylinders 41 a being aligned with the circular ends of cylinders 41 b so that the longitudinal axis of each cylinder 41 a is colinear with the longitudinal axis of its respective neigboring cylinder 41 b . Further as shown, the cylinders are aligned side-to-side within the monolayer, so that the circumferences of neighboring cylinders 41 a touch each other, and the circumferences of neighboring cylinders 41 b likewise touch each other. Thus aligned end-to-end and side-to-side, the cylinders form a rectangular array, whose structure is observable from above (as by an observer at I) through surface 44 a.
[0055] Preferably, there are no gaps between adjacent cylinders in the rectangular array. That is, the cylinders 41 a , 41 b touch each other end-to-end and side-to-side, or come as close as possible to touching each other as is consistent with proper cylinder rotation. Accordingly, there is preferably little or no opportunity for incident light from source L to be scattered from the white faces of the cylinders down to the black faces, where it would be absorbed. Likewise, there is little or no opportunity for incident light to pass between adjacent cylinders, where it would be absorbed in or below lower surface 44 b.
[0056] FIGS. 3 - 4 depict their respective gyricon displays in simplified form, with details not pertinent to the discussion omitted for clarity. FIGS. 5A and 5B provide, respectively, more detailed side and top views of a gyricon display 50 of the invention in a specific embodiment.
[0057] In display 50 , bichromal cylinders 51 of unit (that is, 1:1) aspect ratio are arrayed in a monolayer array having a rectangular packing geometry. Preferably, bichromal cylinders 51 are placed as close to one another as possible in the monolayer. Cylinders 51 are situated in elastomer substrate 52 , which is swelled by a dielectric fluid (not shown) creating cavities 53 in which the cylinders S 1 are free to rotate. The cavities 53 are made as small as possible with respect to cylinders 51 , so that the cylinders nearly fill the cavities. Also, cavities 53 are placed as close to one another as possible, so that the cavity walls are as thin as possible. Preferably, cylinders 51 are of uniform diameter and situated at a uniform distance from upper surface 55 . It will be appreciated that the arrangement of cylinders 51 and cavities 53 in display 50 minimizes both the center-to-center spacing and the surface-to-surface spacing between neighboring bichromal cylinders.
[0058] Cylinders 51 are electrically dipolar in the presence of the dielectric fluid and so are subject to rotation upon application of an electric field, as by matrix-addressable electrodes 54 a , 54 b . The electrode 54 a closest to upper surface 55 is preferably transparent. An observer at I sees an image formed by the black and white pattern of the cylinders 51 as rotated to expose their black or white faces to the upper surface 55 of substrate 52 . For example, the observer sees the white faces of cylinders such as cylinder 51 a and the black faces of cylinders such as cylinder 51 b.
[0059] The side view FIG. 5A reveals the monolayer construction of display 50 . The top view of FIG. 5B illustrates the rectangular packing geometry of cylinders 51 in the monolayer. The cylinders 51 appear as squares visible through transparent upper surface 55 . The centers of cylinders 51 form a square pattern, as shown by exemplary square S.
[0060] The projected areas of cylinders 51 in the plane of surface 55 preferably cover as much of the total area of the plane of surface 55 as possible. To this end, cavities 53 preferably are made as small as possible, ideally no larger than the cylinders themselves (or as close to this ideal as is consistent with proper cylinder rotation). The greater the ratio between the sum of the projected areas of the cylinders in the plane of viewing surface 55 and the total area of viewing surface 55 , the greater the display reflectance and the brighter the display. It will be appreciated that, whereas the maximum areal coverage theoretically possible with spherical bichromal balls (of a single uniform diameter, without interstitial smaller balls) is about 90.7 percent, the maximum for bichromal cylinders is 100 percent. Thus a gyricon display made from a close-packed monolayer of cylinders according to the invention can be made brighter than a gyricon display made from a close-packed monolayer of spherical balls.
[0061] [0061]FIG. 6 shows a side view of a gyricon display 60 of the invention in an alternative embodiment. In display 60 , bichromal cylinders 61 are in a top layer 67 and additional lower layers (here represented by second layer 68 ). Elastomer substrate 62 is swelled by a dielectric fluid (not shown) creating cavities 63 in which the cylinders 61 are free to rotate. Cylinders 61 are electrically dipolar in the presence of the dielectric fluid and so are subject to rotation upon application of an electric field, as by matrix-addressable electrodes 64 a , 64 b . The electrode 64 a closest to upper surface 65 is preferably transparent. An observer at I sees an image formed by the black and white pattern of the cylinders 61 as rotated to expose their black or white faces to the upper surface 65 of substrate 62 .
[0062] To improve the brightness of display 60 so that it is comparable to the brightness of display 50 (of FIGS. 5 A- 5 B), the top layer 67 can be made close-packed, with packing geometry and reflectance characteristics similar to those of the close-packed monolayer of cylinders 51 in display 50 . In this case, cavities 63 are made as small as possible with respect to cylinders 61 , and particularly with respect to cylinders in top layer 67 , so that these cylinders nearly fill the cavities. Also, cavities 63 are placed as close to one another as possible, so that the cavity walls are as thin as possible. Preferably, cylinders in top layer 67 are of uniform diameter and are situated at a uniform distance from upper surface 65 . It will be appreciated that if top layer 67 is close-packed, almost all the light reflected from display 60 so as to be observable to an observer at I is reflected from the white faces of cylinders in top layer 67 . At least for top layer 67 , the arrangement of cylinders 61 and cavities 63 in display 60 minimizes both the center-to-center spacing and the surface-to-surface spacing between neighboring bichromal cylinders. Cylinders in the lower layers (such as layer 68 ) can also be close-packed in order to reduce overall display thickness.
[0063] In general, a monolayer display, such as display 50 of FIGS. 5 A- 5 B, is preferable to a thicker display, such as display 60 of FIG. 6. This is because a thinner display can operate with a lower drive voltage, which affords concomittant advantages such as reduced power consumption, improved user safety, and the possibility of less expensive drive electronics. Further, a thinner display can offer better resolution than a thicker one, due to reduced fringing fields between adjacent black and white pixels. A thicker display offers fringing fields a greater volume in which to develop, and bichromal cylinders caught in the fringing fields are partially but not fully rotated so that they present a mix of black and white to the observer. Consequently, the display appears gray in the fringing field regions. The thin display has minimal fringing fields, and so provides a sharp demarcation between adjacent black and white pixels. (A more detailed discussion of fringing fields in thick and thin gyricon displays, and the effects of these fields on display resolution, is given in Ser. No. 08/713,935 with reference to FIG. 14 and the accompanying text therein.)
[0064] Although it is preferred to align the cylinders end-to-end and side-to-side within the monolayer (or top layer) of the display, so as to form a rectangular array, in alternative embodiments other arrangements of cylinders within the layer can be used. Some examples are seen in FIGS. 7 - 8 .
[0065] [0065]FIG. 7 illustrates a top view of gyricon display 70 of the present invention in an alternative embodiment in which neighboring rows a, b of cylinders 71 are staggered with respect to one another. That is, the cylinders in rows a are aligned end-to-end with each other, as are the cylinders in alternate rows b, but the cylinders in rows a are not aligned side-to-side with those in rows b. The arrangement of FIG. 7 covers the plane as completely as the arrangement of FIG. 5B; however, the arrangement of FIG. 5B can be preferable, because this arrangement produces a well-defined rectangular array of pixels for pixels as small as a single cylinder.
[0066] [0066]FIG. 8 illustrates a top view of gyricon display 80 of the present invention in an alternative embodiments in which cylinders 81 are in random orientations with respect to one another. That is, the longitudinal axes of cylinders 81 are not parallel to one another. This arrangement of cylinders covers the plane less completely than the arrangements shown in FIG. 5B and FIG. 7, and so is less preferable from the standpoint of maximizing display reflectance.
[0067] [0067]FIG. 9 illustrates a top views of gyricon display 90 of the present invention in an alternative embodiment in which the aspect ratio of the cylinders 91 is greater than 1:1. This alternative embodiment covers the plane comparably with the arrangements of FIG. 5B and FIG. 7. It can be useful, for example, in situations where different display resolutions are desired in the x- and y-dimensions (e.g., a display having a resolution of 1200 by 300 dots per inch).
[0068] Up to this point, the discussion of gyricon displays utilizing cylinders instead of spheres has focussed on applications originally utilizing bichromal spheres and how to achieve an enhancement in brightness by using bichromal cylinders. However, gyricon displays utilizing polychromal segmented balls are also known. These displays are fully discussed in U.S. patent application Ser. No. 08/572,779 (Attorney Docket No. D/95115), entitled “POLYCHROMAL SEGMENTED BALLS FOR A TWISTING BALL DISPLAY”; U.S. patent application Ser. No. 08/572,778 (Attorney Docket No. D/95115Q1), entitled “APPLICATIONS OF A TRANSMISSIVE TWISTING BALL DISPLAY”; U.S. patent application Ser. No. 08/572,819 (Attorney Docket No. D/95115Q2), entitled “CANTED ELECTRIC FIELDS FOR ADDRESSING A TWISTING BALL DISPLAY”; U.S. patent application Ser. No. 08/572,927 (Attorney Docket No. D/95115Q3), entitled “HIGHLIGHT COLOR TWISTING BALL DISPLAY”; U.S. patent application Ser. No. 08/572,912 (Attorney Docket No. D/95115Q4), entitled “PSEUDO-FOUR COLOR TWISTING BALL DISPLAY”; U.S. patent application Ser. No. 08/572,820 (Attorney Docket No. D/95116), entitled “ADDITIVE COLOR TRANSMISSIVE TWISTING BALL DISPLAY”; U.S. patent application Ser. No. 08/572,780 (Attorney Docket No. D/95116Q1), entitled “SUBTRACTIVE COLOR TWISTING BALL DISPLAY”; U.S. patent application Ser. No. 08/572,775 (Attorney Docket No. D/95116Q2), entitled “MULTITHRESHOLD ADDRESSING OF A TWISTING BALL DISPLAY”; U.S. patent application Ser. No. 08/572,777 (Attorney Docket No. D/95116Q3), entitled “FABRICATION OF A TWISTING BALL DISPLAY HAVING TWO OR MORE DIFFERENT KINDS OF BALLS”; and U.S. patent application Ser. No. 08/573,922 (Attorney Docket No. D/95271), entitled “ADDITIVE COLOR TRISTATE LIGHT VALVE TWISTING BALL DISPLAY.” All filed concurrently on Dec. 15 ,1995 as well as two divisional applications from U.S. patent application Ser. No. 08/572,779 (Attorney Docket No. D/95115), entitled “POLYCHROMAL SEGMENTED BALLS FOR A TWISTING BALL DISPLAY”, “POLYCHROMAL SEGMENTED BALLS FOR A TWISTING BALL DISPLAY” (Attorney Docket No. D/95115D1) now U.S. Pat. No. A,AAA,AAA, U.S. patent application Ser. No. 08/BBB,BBB (Attorney Docket No. D/95115D2), entitled “APPARATUS FOR FABRICATING POLYCHROMAL SEGMENTED BALLS FOR A TWISTING BALL DISPLAY” filed on Jul. 10, 1997. These applications have been incorporated by reference above.
[0069] A corresponding desirable increased display quality can be achieved for these embodiments of gyricon displays as well if the polychromal balls were replaced by polychromal cylinders.
[0070] For example, a highlight color gyricon display is described which uses a polychromal ball 200 as shown in FIG. 13A. The polychromal ball 200 has 5 portions. Two end segments 202 , 204 are made of a clear material, while the remaining segments 206 , 208 , 210 are made from opaque material. The broad central segment 208 may be made white while slice 206 is colored black and slice 210 is chosen to be any other desired color, for instance red as a highlight color. The polychromal ball 200 may be rotated to show either black, from segment 206 , white from segment 208 or the highlight color from segment 210 .
[0071] A highlight color display using cylinders can be assembled using the techniques described above and using a plurality of cylinders as shown in FIG. 13B. FIG. 13B shows a cylinder 212 with three portions, two cylinder segments 214 , 218 and a central cylinder slice 216 . A cylinder segment is defined as that portion of the cylinder enclosed when the cylinder surface subtended by a plane. A cylinder slice is defined as that portion of a cylinder enclosed when a cylinder is cut by two substantially parallel planes. If cylinder segment 214 is made black, cylinder slice 216 is made white, and cylinder segment 218 is made to be any other color, for example red as a highlight color, then the resulting gyricon display will operate in exactly the same manner as one made from the sphere shown in FIG. 13A except that it will have a corresponding increase in display quality due to better areal coverage obtainable by cylinders over spheres.
[0072] The resulting product would be configured in any of FIGS. 5 through 9 or FIG. 12 With the substitution of cylinder 212 for cylinder elements 51 , 61 , 71 , 81 , 91 or 1201 shown therein. The resulting sheet can be used in any application that previously used a gyricon sheet constructed using the polychromal ball shown in FIG. 13A.
[0073] An alternative highlight color display using cylinders can be assembled using the techniques described above and using a plurality of cylinders as shown in FIG. 13C. The cylinder 220 (FIG. 13C) should provide an increase in display quality over the cylinder 212 (FIG. 13B) when used in a gyricon system, and is therefore the preferred cylinder for use in this type of gyricon system. FIG. 13C shows a cylinder 220 with five portions, 2 cylinder segments 222 , 230 and three cylinder slices 224 , 226 , 228 . If both cylinder segments 222 and 230 are made clear, cylinder slice 226 is made white, cylinder slice 224 is made black and cylinder slice 228 is made to be any other color, for example red as a highlight color, then the resulting gyricon display will operate in exactly the same manner as one made from the sphere shown in FIG. 13A except that it will have a corresponding increase in display quality due to better areal coverage obtainable by cylinders over spheres.
[0074] The resulting product would be configured in any of FIGS. 5 through 9 or FIG. 12 With the substitution of cylinder 220 for cylinder elements 51 , 61 , 71 , 81 , 91 or 1201 shown therein. The resulting sheet can be used in any application that previously used a gyricon sheet constructed using the polychromal ball shown in FIG. 13A.
[0075] An overlay transparency gyricon display is also described which uses a polychromal ball 200 as shown in FIG. 13A. Again the polychromal ball 200 has 5 segments however, both two end segments 202 , 204 and the central segment 208 are made of a clear material, while the remaining segments 206 , 210 are made from opaque material. Segments 206 and 210 may be chosen to be any desired color, for instance one segment may be red as a highlight color and the other black to provide an underline color, or one segment may be red as a highlight color and the other may be yellow as a second highlight color. The polychromal ball 200 may be rotated to be either transparent from central segment 208 , or show either of the two colors from segment 206 or segment 210 .
[0076] An overlay transparency display using cylinders can be assembled using the techniques described above and using a plurality of cylinders as shown in FIG. 13B. FIG. 13B shows a cylinder 212 with three portions, two cylinder segments 214 , 218 and a central cylinder slice 216 . If cylinder segment 214 is made one opaque color, cylinder slice 216 is made clear, and cylinder segment 218 is made to be any other color, for example red as a highlight color, then the resulting gyricon display will operate in exactly the same manner as one made from the sphere shown in FIG. 13A except that it will have a corresponding increase in display quality due to better areal coverage obtainable by cylinders over spheres.
[0077] The resulting product would be configured in any of FIGS. 5 through 9 or FIG. 12 With the substitution of cylinder 212 for cylinder elements 51 , 61 , 71 , 81 , 91 or 1201 shown therein. The resulting sheet can be used in any application that previously used a gyricon sheet constructed using the polychromal ball shown in FIG. 13A.
[0078] An alternative overlay transparency gyricon using cylinders can be assembled using the techniques described above and using a plurality of cylinders as shown in FIG. 13C. The cylinder 220 (FIG. 13C) should provide an increase in display quality over the cylinder 212 (FIG. 13B) when used in a gyricon system, and is therefore the preferred cylinder for use in this type of gyricon system. FIG. 13C shows a cylinder 220 with five portions, 2 cylinder segments 222 , 230 and three cylinder slices 224 , 226 , 228 . If both cylinder segments 222 and 230 and cylinder slice 226 are made clear,, cylinder slice 224 is made any one color and cylinder slice 228 is made to be any other color, for example red as a highlight color, then the resulting gyricon display will operate in exactly the same manner as one made from the sphere shown in FIG. 13A except that it will have a corresponding increase in display quality due to better areal coverage obtainable by cylinders over spheres.
[0079] The resulting product would be configured in any of FIGS. 5 through 9 or FIG. 12 With the substitution of cylinder 220 for cylinder elements 51 , 61 , 71 , 81 , 91 or 1201 shown therein. The resulting sheet can be used in any application that previously used a gyricon sheet constructed using the polychromal ball shown in FIG. 13A.
[0080] A pseudo-four color gyricon is described which uses a polychromal ball 222 as shown in FIG. 14A. The polychromal ball 222 has 7 segments 224 , 226 , 228 , 230 , 232 , 234 , 236 . Both two end segments 224 , 236 and the central segment 230 are made of a clear material, while the remaining segments 226 , 228 , 232 , 234 are made from opaque material. Segments 226 , 228 , 232 , 234 may be chosen to be any combination of desired colors, for instance segment 226 may be red, segment 228 may be green while segment 232 is yellow and segment 234 is blue. The polychromal ball 222 may be rotated to be either transparent from central segment 230 , or to show either of the two colors from segment 226 or segment 234 . Additionally, while using a canted field electrode configuration the polychromal ball 222 may be rotated to a position intermediate between its transparent state and opaque states to partially show two colors, either a portion of segment 226 with a portion of segment 232 or a portion of segment 234 with a portion of segment 228 . Finally, a background color may be chosen, such as white, which is visible when the polychromal ball is rotated to show transparent segment 230 .
[0081] A pseudo-four color gyricon using cylinders can be assembled using the techniques described above and using a plurality of cylinders as shown in FIG. 14B. FIG. 14B shows a cylinder 238 with seven portions, two cylinder segments 240 , 252 and five cylinder slices 242 , 244 , 236 , 248 , 250 . If both cylinder segments 240 , 252 , and the central cylinder slice 246 are made of clear material, and the remaining cylinder slices 242 , 244 , 248 , 250 are made from a selection of opaque colors, then the resulting gyricon display will operate in exactly the same manner as one made from the sphere shown in FIG. 14A except that it will have a corresponding increase in display quality due to better areal coverage obtainable by cylinders over spheres.
[0082] The resulting product would be configured in any of FIGS. 5 through 9 or FIG. 12 with the substitution of cylinder 238 for cylinder elements 51 , 61 , 71 , 81 , 91 or 1201 shown therein. The resulting sheet can be used in any application that previously used a gyricon sheet constructed using the polychromal ball 222 shown in FIG. 14A.
[0083] An additive full color RGB gyricon has been described which uses a polychromal ball 254 as shown in FIG. 15A. The polychromal ball 254 has 3 segments 256 , 258 , 260 . Both of the two end segments 256 , 260 are made of a clear material, while the remaining thin central segment 258 is made from either clear or opaque colored material. Segment 258 will be either red, blue or green. The polychromal ball 254 may be rotated to be substantially transparent, showing only the thin edge of central segment 258 , or rotated to show the fully saturated opaque color of segment 258 , or rotated at intermediate values, using a canted field electrode configuration, to show a partially saturated color of segment 258 . A pixel of the additive full color RGB gyricon is made up of at least one polychromal ball 254 having a central segment 258 in each of the three colors red, blue, and green. That is the minimal number of polychromal balls 254 needed to make one pixel is three, wherein one ball has a red central segment, one ball has a green central segment and one ball has a blue central segment, although in practice one pixel will contain more than three balls.
[0084] An additive full color RGB gyricon using cylinders can be assembled using the techniques described above and using a plurality of cylinders as shown in FIG. 15B. FIG. 15B shows a cylinder 262 with three portions, two cylinder segments 264 , 268 and one cylinder slice 266 . If both cylinder segments 264 , 268 are made of clear material, and the remaining cylinder slice 266 is made from either a clear or opaque color, then the resulting gyricon display will operate in exactly the same manner as one made from the sphere shown in FIG. 15A except that it will have a corresponding increase in display quality due to better areal coverage obtainable by cylinders over spheres.
[0085] The resulting product would be configured in any of FIGS. 5 through 9 or FIG. 12 with the substitution of cylinder 262 for cylinder elements 51 , 61 , 71 , 81 , 91 or 1201 shown therein. The resulting sheet can be used in any application that previously used a gyricon sheet constructed using the polychromal ball 262 shown in FIG. 15A.
[0086] A multi-layer subtractive CMY or CMYK color gyricon has been described which also uses a polychromal ball 254 as shown in FIG. 15A. Again, both of the two end segments 256 , 260 are made of a clear material, but the remaining thin central segment 258 is made from clear colored material. Segment 258 will be either cyan, magenta, yellow or black. The polychromal ball 254 may be rotated to be substantially transparent, showing only the thin edge of central segment 258 , or rotated to show the fully saturated color of segment 258 , or rotated at intermediate values, using a canted field electrode configuration, to show a partially saturated color of segment 258 . A pixel of the subtractive full color CMY gyricon is made up of at least one polychromal ball 254 having a central segment 258 in each of the three colors cyan, yellow, and magenta. A pixel of the subtractive full color CMYK gyricon is made up of at least one polychromal ball 254 having a central segment 258 in each of the three colors cyan, yellow, and magenta plus black. However, unlike the previously described RGB gyricon the polychromal balls of a single color reside in separate layers superposed on each other. That is, one layer will contain polychromal balls 254 wherein segment 258 is a transparent magenta color, another layer will contain polychromal balls 254 wherein segment 258 is a transparent cyan color, a the third layer will contain polychromal balls 254 wherein segment 258 is a transparent yellow color, and possibly in a fourth layer there will be polychromal balls 254 wherein segment 258 is black. The transparent segments 258 act as color filters. The three layers may be contained within one sheet or each layer may reside in its own sheet, as is known in the art for polychromal spheres. Each layer may be rotated independently of the other layers, that is, it is possible to rotate only the polychromal balls 254 which have the same color segment 258 without affecting the polychromal balls 254 which have different color segments 258 . Independent rotation of layers may be accomplished, by either locating each layer independently of the others with a dedicated addressing electrode scheme or by using for each layer elements which have different rotation thresholds and locating all the elements in one layer and using a single addressing electrode scheme.
[0087] A subtractive full color CMY or CMYK gyricon using cylinders can be assembled using the techniques described above and using a plurality of cylinders as shown in FIG. 15B. FIG. 15B shows a cylinder 262 with three portions, two cylinder segments 264 , 268 and one cylinder slice 266 . If both cylinder segments 264 , 268 are made of clear material, and the remaining cylinder slice 266 is made from a clear color, then the resulting gyricon display will operate in exactly the same manner as one made from the sphere shown in FIG. 15A except that it will have a corresponding increase in display quality due to better areal coverage obtainable by cylinders over spheres.
[0088] The resulting product could be configured such that each layer appears as in any of FIGS. 5 through 9 or FIG. 12 with the substitution of cylinder 262 for cylinder elements 51 , 61 , 71 , 81 , 91 or 1201 shown therein. The resulting sheet can be used in any application that previously used a gyricon sheet constructed using the polychromal ball 262 shown in FIG. 15A.
[0089] Additive full color RGB gyricons have been described which use polychromal balls as a light valve.
[0090] In a first approach, a polychromal ball 254 , as shown in FIG. 15A, is used. Both of the two end segments 256 , 260 are made of a clear material, while the remaining central segment 258 is made from opaque colored material. The polychromal ball 254 may be rotated to be substantially transparent, showing only the thin edge of central segment 258 , or rotated to be completely opaque showing all of segment 258 , or rotated at intermediate values, using a canted field electrode configuration, to be partially opaque showing a portion of segment 258 . Each polychromal ball 254 is used as a valve to either reveal, obscure, or partially obscure a colored dot situated behind the polychromal ball 254 depending on the orientation of the polychromal ball 254 . In a minimum set, the colored dots will be of least three colors (red, blue and green), and a pixel will contain at least one dot of each color and its associated polychromal ball 254 to act as a light valve.
[0091] An additive full color RGB gyricon using cylinders as a light valve can be assembled using the techniques described above and using a plurality of cylinders as shown in FIG. 15B. FIG. 15B shows a cylinder 262 with three portions, two cylinder segments 264 , 268 and one cylinder slice 266 . If both cylinder segments 264 , 268 are made of clear material, and the remaining cylinder slice 266 is made from opaque material, then the resulting gyricon display will operate in exactly the same manner as one made from the sphere shown in FIG. 15A except that it will have a corresponding increase in display quality due to better areal coverage obtainable by cylinders over spheres. Due to the better areal coverage obtainable by cylinders, the colored dots to be obscured by the light valve may be replaced with a shape described by the projection of a cylinder rather than a circle (which is the shape projected by a sphere). That shape depends on the shape of the specific cylinders used and may be either a square or a rectangle.
[0092] The resulting product would be configured in any of FIGS. 5 through 9 or FIG. 12 with the substitution of cylinder 262 for cylinder elements 51 , 61 , 71 , 81 , 91 or 1201 shown therein. The resulting sheet can be used in any application that previously used a gyricon sheet constructed using the polychromal ball 262 shown in FIG. 15A.
[0093] In a second approach, a polychromal ball 270 , as shown in FIG. 16A, is used. Both of the two end segments 272 , 278 are made of a clear material, while the two central segments 274 , 276 are made from opaque colored material. One central segment 274 is colored black, while the other central segment 276 is colored white. The polychromal ball 270 may be rotated to be substantially transparent, showing only the thin edge of both central segments 274 , 276 , to be white showing all of segment 274 , to be black showing all of segment 276 or rotated at intermediate values, using a canted field electrode configuration, to be partially opaque showing a portion of either segment 274 , 276 . Each polychromal ball 270 is used as a valve to either reveal, obscure, or partially obscure a colored dot situated behind the polychromal ball 270 depending on the orientation of the polychromal ball 270 . In a minimum set, the colored dots will be of least three colors (red, blue and green), and a pixel will contain at least one dot of each color and its associated polychromal ball 270 to act as a light valve.
[0094] An additive full color RGB gyricon using cylinders as a light valve can be assembled using the techniques described above and using a plurality of cylinders as shown in FIG. 16B. FIG. 16B shows a cylinder 280 with three portions, two cylinder segments 282 , 288 and two cylinder slices 284 , 286 . If both cylinder segments 280 , 288 are made of clear material, and the two cylinder slices 284 , 286 are made from opaque black and white material respectively, then the resulting gyricon display will operate in exactly the same manner as one made from the sphere shown in FIG. 16A except that it will have a corresponding increase in display quality due to better areal coverage obtainable by cylinders over spheres. Due to the better areal coverage obtainable by cylinders, the colored dots to be obscured by the light valve may be replaced with a shape described by the projection of a cylinder rather than a circle (which is the shape projected by a sphere). That shape depends on the shape of the specific cylinders used and may be either a square or a rectangle.
[0095] The resulting product would be configured in any of FIGS. 5 through 9 or FIG. 12 with the substitution of cylinder 280 for cylinder elements 51 , 61 , 71 , 81 , 91 or 1201 shown therein. The resulting sheet can be used in any application that previously used a gyricon sheet constructed using the polychromal ball 270 shown in FIG. 15A.
[0096] Cylinder Fabrication Techniques
[0097] [0097]FIG. 10 (PRIOR ART) illustrates a side view of a spinning-disk mechanism 100 for fabrication of bichromal spherical balls. Mechanism 100 is equivalent to the “spinning disc configuration 50 ” disclosed in the '098 patent incorporated by reference hereinabove; see FIG. 4 therein and the accompanying description at col. 4, line 25 to col. 5, line 7.
[0098] In the prior art, the spinning disk mechanism was used in conjunction with low-viscosity hardenable liquids. Low viscosity was considered necessary to ensure the formation of good-quality bichromal spheres; if viscosity was too high, the ligaments streaming off the disk would freeze in place instead of fragmenting into balls as desired. For example, as stated in the '098 patent (col. 5, line 64-col. 6 line 2), “the black and white pigmented liquids are delivered . . . in a heated, molten state . . . so that they flow freely and do not harden prematurely, i.e., long enough to prevent the ligaments from freezing.”
[0099] According to the invention, the spinning disk mechansm is used in conjunction with high-viscosity hardenable liquids. These liquids do, indeed, “freeze” (harden) in place, the very result not desired in the prior art. However, according to the invention the frozen ligaments that are considered undesirable for making bichromal spheres can be used to make bichromal cylinders. FIG. 11 illustrates this. A spinning disk 110 , shown here in a top view, is used according to the technique of the '098 patent to form bichromal ligaments, but with high-viscosity hardenable white and black liquids being used in place of the low-viscosity liquids of the prior art. The resulting ligaments 115 harden into fine bichromal filaments (roughly analogous to the way in which molten sugar hardens into filaments when spun in a cotton-candy machine). The filaments can be combed or otherwise aligned and then cut into even lengths, as with a tungsten carbide knife or a laser, to produce the desired bichromal cylinders. End-to-end and side-to-side alignment of the cut cylinders can be achieved by precise alignment of the filament ends on the working surface where the cutting takes place; for example, if the cylinders are to have aspect ratio 1:1 and diameter 100 microns, then the filament ends can be aligned with one another to within a tolerance on the order of 5 to 10 microns.
[0100] In the same manner that a modification of the method used to produce bichromal spheres can be used to produce bichromal cylinders, just so can a modification of the method used to produce polychromal spheres be used to produce polychromal cylinders. A modification of the spinning-disk technique can be used to fabricate multichromal balls. The modification uses a spinning multiple-disk assembly instead of a single spinning disk. An example is illustrated in FIG. 17A. Assembly 1700 has three disks 1710 , 1711 , 1712 that rotate uniformly about shaft 1715 . The concave or “dish-shaped” outer disks 1710 , 1712 curve or slope toward the flat inner disk 1711 at their respective peripheries. Other geometries are possible, and the exact geometry for a particular embodiment can be determined, for example, by hydrodynamic modeling, as will be appreciated by those of skill in the art.
[0101] The three-disk assembly of FIG. 17A can be used to produce multichromal balls and cylinders having certain useful properties, as will be discussed below. It will be appreciated, however, that other assemblies having different numbers of disks can also be used in the present invention, with the number and configuration of the disks varying according to the kind of ball that is to be produced.
[0102] If differently pigmented low viscosity hardenable plastic liquids are introduced to each side of each of the three disks 1710 , 1711 , 1712 in FIG. 17A, flow patterns of pigmented liquids at the edge of the disks can be obtained that result in multichromal ligaments that break up to form multichromal balls. FIG. 17B illustrates a close-up cross-sectional view of an example of the flow of pigmented plastic liquids at the edge of the three-disk assembly of FIG. 17A. First and second liquids 1721 , 1722 flow over opposite sides of disk 1710 , whose downward-sloping edge can be seen in the figure. Third and fourth liquids 1723 , 1724 flow over opposite sides of disk 1711 , and fifth and sixth liquids 1725 , 1726 flow over opposite sides of disk 1712 . The combined flows give rise to ligament 1730 , which breaks up into multilayer balls such as the ball 1740 illustrated in FIG. 17C (side view) and FIG. 17D (top view).
[0103] Ball 1740 has six segments corresponding to the six streams of plastic liquid used to make it. Segments 1741 and 1742 join at planar interface 1743 ; segments 1744 and 1745 , at planar interface 1746 ; and segments 1747 and 1748 , at planar interface 1749 . If different pigments are used in the various plastic liquids 1721 , 1722 , 1723 , 1724 , 1725 , 1726 , then ball 1740 will be multichromal. In general, a three-disk assembly like the one shown in FIG. 17A can produce gyricon balls having six segments of up to six different colors.
[0104] More generally, a multi-disk assembly with N disks can be used to produce gyricon balls having up to 2N segments in arbitrary color combinations. Black, white, or other color pigments or dyes can be used, alone or in combination, so that segments can be made in virtually any desired color or shade. Segments can be made clear by using unpigmented, undyed plastic liquid. Different segments can be made to have different widths by adjusting the flow rates of the various plastic liquids used to make the segments, with faster flow rates corresponding to wider segments and slower rates to narrower. Two or more adjacent segments can be made the same color so that they effectively merge to form a single broader segment.
[0105] As discussed earlier and shown in FIG. 11, when the spinning disk mechansm is used in conjunction with high-viscosity hardenable liquids these liquids do, indeed, “freeze” (harden) in place to create ligaments that can be used to make polychromal cylinders. FIG. 18 illustrates this for the case of a multiple disk system. When a spinning disk assembly 180 , shown here in a top view, is used according to the technique of the '098 patent to form bichromal ligaments, but with high-viscosity hardenable liquids being used in place of the low-viscosity liquids of the prior art the resulting ligaments 185 harden into fine bichromal filaments (roughly analogous to the way in which molten sugar hardens into filaments when spun in a cotton-candy machine). The filaments can be combed or otherwise aligned and then cut into even lengths, as with a tungsten carbide knife or a laser, to produce the desired bichromal cylinders. End-to-end and side-to-side alignment of the cut cylinders can be achieved by precise alignment of the filament ends on the working surface where the cutting takes place; for example, if the cylinders are to have aspect ratio 1:1 and diameter 100 microns, then the filament ends can be aligned with one another to within a tolerance on the order of 5 to 10 microns.
[0106] By way of example, any given gyricon cylinder segment can be: black; white; clear (that is, essentially transparent and without chroma, like water or ordinary window glass); a transparent color (e.g., transparent red, blue, or green, as for certain additive color applications; transparent cyan, magenta, or yellow, as for certain subtractive color applications); an opaque color of any hue, saturation, and luminance; any shade of gray, whether opaque or translucent; and so forth. Any given gyricon cylinder segment can also have other optical properties polarization, birefringence, phase retardation, light absorption, light scattering, and light reflection. For ease of reference, “achromatic colors” will be used herein below to refer to colors essentially lacking in chroma, that is, to black, white, gray, and clear, and “chromatic colors” will be used hereinbelow to refer to other colors, including red, orange, yellow, green, blue, indigo, violet, cyan, magenta, pink, brown, beige, etc.
[0107] Alternative techniques can also be used to produce the bichromal cylinders. For example, injection molding can be used, albeit perhaps with some inconvenience. As another example, the bichromal jet technique disclosed in the '594 patent can be used, again substituting high-viscosity hardenable liquids for the usual low-viscosity liquids.
[0108] No-Cavities Cylinder Display
[0109] In a gyricon display made with swelled elastomer, each bichromal cylinder is situated in a cavity. To achieve the closest possible packing of bichromal cylinders in such a display, the cavities are preferably made as small and as close together as possible.
[0110] To achieve still higher packing density, a gyricon display can be constructed without elastomer and without cavities. In such a display, the bichromal cylinders are placed directly in the dielectric fluid. The cylinders and the dielectric fluid are then sandwiched between two retaining members (e.g., between the addressing electrodes). There is no elastomer substrate. In this case, the packing geometry can closely approach, or even achieve, the ideal close-packed monolayer geometry shown in FIG. 4.
[0111] [0111]FIG. 12 illustrates a side view of a no-cavities gyricon display. In display 1200 , a monolayer of bichromal cylinders 1201 of uniform diameter is situated in dielectric fluid 1209 between matrix-addressable electrodes 1204 a , 1204 b . Preferably cylinders 1201 of unit aspect ratio are arranged in a rectangular array, aligned end-to-end and side-to-side within the monolayer and packed as close together as is possible consistent with proper cylinder rotation. Cylinders 1201 are electrically dipolar in the presence of dielectric fluid 1209 and so are subject to rotation upon application of an electric field, as by electrodes 1204 a , 1204 b . The electrode 1204 a closest to upper surface 1205 is preferably transparent. An observer at I sees an image formed by the black and white pattern of the cylinders 1201 as rotated to expose their black or white faces to the upper surface 1205 of display 1200 .
[0112] Electrodes 1204 a , 1204 b serve both to address cylinders 1201 and to retain cylinders 1201 and fluid 1209 in place. Preferably the spacing between electrodes 1204 a , 1204 b is as close to the diameter of cylinders 1201 as is possible consistent with proper cylinder rotation. Cylinders 1201 and fluid 1209 can be sealed in display 1200 , for example by seals at either end of the display (not shown). The close packing of cylinders 1201 in the monolayer, together with the close spacing of the electrodes 1204 a , 1204 b , ensures that cylinders 1201 do not settle, migrate, or otherwise escape from their respective positions in the monolayer.
[0113] It should be pointed out that the no cavities cylinder display is not limited to the bichromal cylinders 1201 shown in FIG. 12, but in fact any of the cylinders described herein may be used to construct the no cavities cylinder display.
[0114] Conclusion
[0115] A new gyricon display based on cylindrical elements instead of spherical elements has been described. This new display makes possible a close-packed monolayer providing nearly 100 percent areal coverage. Such a display provides superior reflectance and brightness, and requires no interstitial particles.
[0116] The foregoing specific embodiments represent just some of the possibilities for practicing the present invention. Many other embodiments are possible within the spirit of the invention. For example:
[0117] The electrical anisotropy of a gyricon cylinder need not be based on zeta potential. It is sufficient that there is an electrical dipole moment associated with the cylinder, the dipole moment being oriented with respect to the long axis of the cylinder in such a way as to facilitate a useful rotation of the cylinder in the presence of an applied external electric field. (Typically, the dipole moment is oriented along a medial axis of the cylinder.) Further, it should be noted that a gyricon cylinder can have an electrical monopole moment in addition to its electrical dipole moment, as for example when the dipole moment arises from a separation of two positive charges of different magnitudes, the resulting charge distribution being equivalent to a positive electrical monopole superposed with an electrical dipole.
[0118] The optical anisotropy of a gyricon cylinder need not be based on black and white. For example, bichromal cylinders having hemispheres of two different colors, e.g. red and blue, can be used. As another example, cylinders that are black in one hemisphere and mirrored in the other might be used for some applications. In general, various optical properties can vary as different aspects of a gyricon cylinder are presented to an observer, including (but not limited to) light scattering and light reflection in one or more regions of the spectrum. Thus the gyricon cylinders can be used to modulate light in a wide variety of ways.
[0119] The incident light that encounters a gyricon display need not be restricted to visible light. Given suitable materials for the gyricon cylinders, the incident “light” can be, for example, infrared light or ultraviolet light, and such light can be modulated by the gyricon display.
[0120] On several occasions the foregoing description refers to a planar monolayer of bichromal cylinders. However, persons of skill in the art will appreciate that a gyricon display (or a sheet of bichromal cylinders for use in such a display) made of a flexible material can be temporarily or permanently deformed (for example, flexed, folded, or rolled) so as not to be strictly planar overall. In such cases, the plane of a monolayer can be defined, for example, in a locally planar neighborhood that includes the gyricon cylinder or cylinders of interest. Also, it will further be apprecated that in practice the monolayer can vary somewhat from what has been described, for example, due to manufacturing tolerances or slight imperfections of particular gyricon sheets.
[0121] Accordingly, the scope of the invention is not limited to the foregoing specification, but instead is given by the appended claims together with their full range of equivalents. | A gyricon or twisting-particle display based on nonspheroidal (e.g., substantially cylindrical) optically anisotropic particles disposed in a substrate. The particles can be either bichromal or polychromal cylinders, preferably aligned parallel to one another and packed close together in a monolayer. A rotatable disposition of each particle is achievable while the particle is thus disposed in the substrate; for example, the particles can already be rotatable in the substrate, or can be rendered rotatable in the substrate by a nondestructive operation performed on the substrate. In particular, the substrate can be made up of an elastomer that is expanded by application of a fluid thereto so as to render the particles rotatable therein. A particle, when in its rotatable disposition, is not attached to the substrate. The close-packed monolayer configuration of particles provides excellent brightness characteristics and relative ease of manufacture as compared with certain other high-brightness gyricon displays. The substrate containing the cylinders can be fabricated with the swelled-elastomer techniques known from spherical-particle gyricon displays, with a simple agitation process step being used to align the cylinders within the sheeting material. Techniques for fabricating the cylinders are also disclosed. | 6 |
FIELD OF THE INVENTION
The invention relates to a monobutyltin trichloride (MBTC) which is particularly suitable for hollowware coating and which is stabilized against the influence of moisture and darkening.
BACKGROUND OF THE INVENTION
It is known to apply coatings of all sorts of metal oxides, in particular of tin dioxide, to glass containers in order to improve their resistance to impact and abrasion. This tin dioxide coating acts as a primer for the so-called cold end coating applied after the annealing process.
Customarily, tin compounds are brought into contact with the hot glass surface in vapor or spray form in the so called hot end coating, a thin tin dioxide coating being produced pyrolytically. On account of their physical properties, such as water solubility, vaporizability and the like, and of their low toxicity, monoorganotin trichlorides are, in particular, employed for this purpose (DE-C-25 41 710).
Depending on the purity and quality of the products, however, it has been shown in the processing of these compounds that due to the occurrence of solid particles, in particular after long storage, significant trouble can occur with the glass coating process. significant trouble can occur with the glass coating process.
According to EP-A-0 132 024, to avoid the occurrence of solid particles, dopants of all sorts of types, in particular alcohols, are added to the monoalkyltin trihalides.
A further problem which occurs with monobutyltin trichloride after long storage is darkening, which can lead at its most pronounced to a dark brown coloration. This dark coloration of the product can likewise significantly adversely affect the working process, in particular in measuring and metering operations. Furthermore, with monobutyltin trichloride visible crystallizations very rapidly occur under the influence of moisture; on longer action, presumably caused by hydrate formation, the formation of a liquid multiphase system can even occur.
BRIEF SUMMARY OF THE INVENTION
It has been found that a monobutyltin trichloride composition stabilized against the effects of moisture and darkening is obtained when one or more glycerol esters of aliphatic carboxylic acids are added to it. Suitable esters are the glycerol mono-, di- and triesters of aliphatic, optionally unsaturated carboxylic acids having 1 to 18 carbon atoms. Suitable glycerol esters are, for example, acetates, propionates, 2-ethylhexanoates, valerates, caprylates, dodecanoates and octadecanoates. Particularly active here are glycerol mono- and diacetates or mixtures of the two, and 2-ethylhexanoic acid esters.
Amounts of additive from 0.5 to 10% by weight can be employed; as a rule 0.5 to 1.5% by weight is adequate.
DETAILED DESCRIPTION OF THE INVENTION
The stabilizers employed according to the invention are in this case surprisingly considerably more active than the dopants of the prior art. Thus, for example (see examples), when using 1% glycerol monoacetate crystallization only occurs to 15%, while in the case of the dopants according to EP-A-0 132 024 crystallization is present on the entire surface after the same time.
The activity of the stabilizers employed is explained in greater detail by means of the following examples.
Testing of MBTC for stability to environmental moisture
In order to test the effects of environmental moisture on MBTC, MBTC samples standing open are observed and the time is determined after which noticable changes in the product can be recorded in each case.
For this purpose, clock glasses of 10 cm diameter are provided with 2 ml each of MBTC sample and are exposed next to one another to the surrounding air while standing open in a hood.
The hood front flap is kept open 15 cm above the bottom; the center of the sample glasses is located at a distance of 10 cm from the opening.
The tests are repeated using different positions of the clock glasses relative to one another and the test results meaned in order to compensate for any possible test scatter.
In the experimental arrangement, this crystallization begins at the edge of the liquid surface and then continues inwards.
The table indicates the proportion of the surface crystallized relative to the total surface area. The lower the proportion of the surface crystallized, the better the stabilizing action.
__________________________________________________________________________Glmono: glycerol monoacetateGldiac: glycerol diacetateGltriac: glycerol triacetateGl-2eth-mono glycerol 2-ethylhexanoic acid monoesterGl-2eth-di: glycerol 2-ethylhexanoic acid diesterTest MBTC MBTC MBTC MBTC MBTC MBTC MBTC MBTCperiodwithout + 1% + 0.5% + 1% + 1.5% + 0.5% + 1% + 1.5%(Hours)additions Ethanol * Glmono Glmono Glmono Gldiac Gldiac Gldiac__________________________________________________________________________1 100% 15% 10% 5% 2% 10% 5% 1%2 -- 50% 15% 10% 5% 15% 10% 5%3 -- 100% 50% 15% 10% 40% 15% 10%__________________________________________________________________________ * Comparison experiment
__________________________________________________________________________Test MBTC + MBTC + MBTC +period0.5% 1% 1.5% MBTC + 1% MBTC + 1%(hours)Gltriac Gltriac Gltriac Gl-2eth-mono Gl-2eth-di__________________________________________________________________________1 15% 10% 5% 5% 5%2 20% 15% 10% 5% 5%3 50% 25% 15% 10% 10%__________________________________________________________________________
Testing of MBTC for stability to darkening
MBTC darkens on standing in the light, which leads to the initially almost water-clear liquid assuming a dark-brown appearance after some time.
An additional effect which is seen, in particular with the mono/diesters of glycerol, is a stabilization against this darkening, so that this process is considerably slowed.
__________________________________________________________________________ Starting color Stored 1 week Stored 1 month Stored 3 months__________________________________________________________________________MBTC + 1% almost water- yellow light brown dark brownEthanol clearMBTC + 1% almost water- almost water- almost water- light yellowGlmono clear clear clearMBTC + 1% almost water- almost water- almost water- light yellowGldiac clear clear clear__________________________________________________________________________ * Comparison experiment | The invention relates to monobutyltin trichloride which, as a stabilizer, comprises one or more glycerol esters of optionally unsaturated aliphatic carboxylic acids having 1 to 18 carbon atoms. | 2 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] Sometimes visibility can change within minutes, helicopters operations from small surface ships can be cut short by rough seas, low visibility and darkness, landing being by far the greatest problem. This invention is designed to greatly help solve this problem in an economical way; a system that is effective and reduces the need for at least some of the costly electronic systems. This is an electrical system not an electronic one.
[0003] 2. Description of the Related Art
[0004] Radars can be too powerful to be used at short ranges. Some can have blind spots close to the ship because of sea return. Others are not designed for tracking helicopters all the way to the deck.
[0005] To guide a helicopter all the way to the deck, a high-resolution surface surveillance radar with effective filters that take away sea and rain clutter. Integrated with the radar is an electro-optical infrared camera to provide a clearer picture of the helicopter to the controllers. The above system can solve the problem. Then there is the cost factor to consider for the above and other highly technical electronic systems.
BRIEF SUMMARY OF THE INVENTION
[0006] On a small ship especially, visibility can suddenly deteriorate to a degree that, the approach for landing a helicopter becomes a hazardous task. For visual landing in rough seas, low visibility and darkness, this light system alone, or in combination with one or more less complex electronic systems for added safety can be used. Better visibility will be possible for the air crew to make a safe approach and landing. This is an electrical system not an electronic one. No high profile technical knowledge is needed to operate or repair this system, just some basic knowledge of electrical theory.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] FIG. 1 is a top view of a light-circle showing the lighting effects of several light units.
[0008] FIG. 2 is a sectional view of FIG. 1 .
[0009] FIG. 3 is a top view of a helicopter landing into the light-circle.
[0010] FIG. 4 is a side view of a light unit.
[0011] FIG. 5 is a schematic of an electromagnet and its DC circuit.
[0012] FIG. 6 is a top view of the light unit.
[0013] FIG. 7 is a front view of the light unit.
[0014] FIG. 8 is a block diagram showing the electrical parallel connections within each light unit and an input AC power supply connection.
[0015] FIG. 9 is a block diagram showing the cable length and type between the light units.
[0016] FIG. 10 is a block diagram showing the electrical connections within each light unit and an input DC power supply connection.
[0017] FIG. 11 is a side view of a light unit with a portable, metallic stabilizing plate.
[0018] FIG. 12 is a block diagram showing the electrical series connections to within each light unit and an input AC power supply.
DETAILED DESCRIPTION
[0019] FIG. 1 embodies the combination of the heating and lighting effects of several light units 20 A, 20 B, 20 C, 20 D, 20 E, 20 F, 20 G, 20 H, forming a light-circle 10 with an intense, red light-center 15 . This light system will generate the necessary visibility needed by a pilot to safely land a helicopter, in rough seas, low visibility and darkness.
[0020] The light units 20 A- 20 H should be placed as close to an actual circle as is humanly possible. This embodiment has 8 light units 20 A- 20 H placed approximately 45 degrees apart. Other numbers of light units can be used. Light units 20 A- 20 H are connected by means of connecting N, O, P, Q, R, S, T, U. A portable or fixed power supply is connected to the light-circle 10 by a connecting means N. See FIG. 2 .
[0021] FIG. 3 shows a helicopter H landing in the light-circle 10 of the light system. A pilot can get his bearing from the positions of one or more light units 20 A- 20 H. The up and down movement of the light units 20 A- 20 H, can tell the pilot the degree to which the ship is rocking from side to side. The pilot can slowly head for the intense, red light-center 15 and go down, see FIG. 1 and FIG. 2 .
[0022] FIG. 4 is a side view of a light unit 20 A- 20 H. Mechanically, each light unit comprises a base 22 , a body 24 and a carrying handle 26 . Electrically, each light unit comprises a floodlight lamp 40 , a circular electromagnet 42 and its circuit 42 A, an electrical connector (female) 44 A, and on the opposite side is another connector (female) 44 B, not shown.
[0023] A means for lighting can comprise a light bulb, a floodlight lamp, a heat light or others. It can range over a wide range of wattages; it can be between 60 and 1000 watts. It can have a narrow or wide light beam. It can generate a white light or color light of many types, red, green, blue and yellow being only a few.
[0024] For practical purposes, a means for lighting 40 will be an energy-efficient, outdoor, AC floodlight lamp 40 that generate a red light with a wide beam. A lamp 40 with substantial wattage, an 80 to 100 watts lamp would be ideal. The lamp 40 should be able to withstand harsh weather conditions.
[0025] The center line 50 A of the lamp 40 should make an approximately 45 degrees angle with the horizontal base 22 . Other angles can be used as well. The light beam 50 can shine upward slightly to create a depth in the intense, red light-center 15 of the light circle 10 . A pilot can see the landing area better, review FIG. 1 . The electromagnet 42 will hold a light unit 20 A- 20 H in one place on the metallic deck 55 of a ship. The electromagnet 42 is centered in the base 22 . Each of the light unit's body 24 should be painted red. This would help with the visibility of the light-circle 10 .
[0026] FIG. 5 is the embodiment of the electromagnet 42 and its circuit 42 A. Alternating current (AC) powering an electromagnet will be less efficient than a comparable direct current (DC) powered electromagnet. It will suffer from hysteresis losses in its magnetic core, due to the repeatedly reversing the polarity of the magnetic domains in the core; this consumes power. The solution would be to use a DC circuit 42 A to power the electromagnet 42 . This circuit 42 A will give you a pulsating DC, a more complex circuit to get a linear DC will not be necessary.
[0027] FIG. 6 is a top view of a light unit showing its body 24 , carrying handle 26 and lamp 40 . FIG. 7 is a front view of the light unit 20 A- 20 H showing its body 24 , base 22 , carrying handle 26 , and lamp 40 . The electromagnet 42 should be just strong enough to stabilize the light unit against the ship's metallic deck 55 , but can be lifted by an adult.
[0028] Series circuits use a single path to connect the electric source or sources to the output device (load) or devices (loads). They have limited uses because any change in one circuit part affects all the circuit parts. For an example, some Christmas tree lights are connected in series, when one bulb goes out they all go out. Therefore, parallel circuits are the most practical ones to use in this system.
[0029] FIG. 8 shows each light unit 20 A- 20 H with its floodlight lamp 40 and the electromagnet 42 and its DC circuit 42 A, they are connected in parallel with an electrical AC input.
[0030] FIG. 9 shows the means for connecting the light units N, O, P, Q, R, S, T, U, of the light system. The input electric power cable N can be to a portable or fixed AC or DC power supply. The electric power cables O, P, Q, R, S, T, U between the light units 20 A, 20 B, 20 C, 20 D, 20 E, 20 F, 20 G, 2011 can be of a certain length. The circumference of a light-circle 10 can be changed with different sets of lengths. Each light unit 20 A- 20 H has two electrical connectors (female) 44 A and 44 B, review FIG. 4 . Most cables used to transmit or distribute electric power are coaxial cables.
[0031] In FIG. 10 shows each light unit 20 A- 20 H with its floodlight lamp 60 and an electromagnet 62 both of DC specifications, and both are connected in parallel with an electrical DC input.
[0032] FIG. 11 shows a light unit 20 A- 20 H holding onto a fairly wide, light metallic plate 70 with its electromagnet 42 . On a non-metallic surface 75 the wide portable metallic plate 70 helps stabilize the light unit 20 A- 20 H.
[0033] FIG. 12 is an alternative embodiment showing each light unit 20 A- 20 H with its floodlight lamp 40 and the electromagnet 42 and its DC circuit 42 A, they are connected in series with an electrical AC input.
[0034] No new technology is needed. The parts for this system can be purchased off a store shelf, a minor modification of an existing item, or made by relatively minor fabrication. No high profile technical knowledge is needed to operate or repair this system, just some basic knowledge of electrical theory. | This is an electrical system not an electronic one. The light units should be placed as close to an actual circle as possible. For a helicopter visual landing in rough seas, low visibility and darkness, the approach for landing becomes a hazardous task. Good visibility of the landing area will be possible due to this system effectiveness. The helicopter can now become a truly all-weather vehicle. No new technology is needed. The parts for the system can be purchased off a store shelf, a minor modification of an existing item, or made by relatively minor fabrication. | 1 |
FIELD OF THE INVENTION
Flow sensors or air mass flow sensors are known in practice for measuring flow velocities, volume flows or air mass flows. With the aid of these devices, the corresponding variable is output as a signal value, be it as voltage, as frequency, as pulse-width ratio etc., in accordance with a characteristic curve. The characteristic curve, however, in this context usually corresponds to static air mass flows. For this reason, correction methods must be used in the case of pulsating flows.
BACKGROUND INFORMATION
In order to correct false indications in the case of pulsating flows, for example in the intake tract of an internal combustion engine, the following methods are used.
A correction map is stored in the engine control unit of the internal combustion engine, which can be addressed via the characteristic quantities of the speed of the internal combustion engine (measured via a speed sensor) and the load (e.g. the throttle valve opening position). In addition, nonlinear optimized characteristic curves are used in engine control units.
Raw signals U HFM of an air mass detector are detected in that the air mass detector is exposed to an air mass flow m at different operating points on an engine test bench and the signal generated by the air mass detector is recorded. The raw signals U HFM of the air mass detector are converted into air mass flow values by interpolation on an output characteristic. Subsequently, average values of the air mass flow values are formed via integral multiples of a pulsation period for the respective operating points of the internal combustion engine, given by the speed and the specific output. A deviation dm/m, which corresponds to the average deviation of the average air mass flow of a comparison air mass flow, is calculated for the respective operating points (n, p ME ) of the internal combustion engine. Subsequently, the quadratic norm (X 2 ) over the matrix of the deviation is calculated. An adjusted characteristic curve in the sense of an optimization is produced, the characteristic curve being optimized with respect to the condition that the quadratic norm (X 2 ) becomes a minimum. The raw signals U HFM of the air mass detector are converted into air mass flow values by interpolation to the adjusted characteristic curve, several of the above-mentioned method steps being iteratively run through by repetition.
A flow meter is known from German Published Patent Application No. 197 43 340. The flow meter takes the form of a measuring tube through which the medium to be measured flows, the medium being exposed to at least one ultrasonic transmitter/receiver unit. At least one reflector is situated in the measuring tube for reflecting an ultrasonic signal sent by an ultrasonic transmitter/receiver unit either directly or via a reflection on a measuring tube wall in the direction of the same or of other ultrasonic transmitter/receiver units. To avoid surface waves in the reflection, an angle of incidence of the ultrasonic signal on a reflector, measured between a normal to the surface and a reflector and the incident ultrasonic signal, is provided, which is greater than a Rayleigh angle or the material properties of the reflectors have an appropriately high Rayleigh speed or there is a combination of these.
SUMMARY OF THE INVENTION
Following the method provided according to the present invention, a more precise measurement of air mass flows can be achieved even in pulsating, i.e. non-static air mass flows. When used in the intake tract of an internal combustion engine, for example, this allows for a more precise detection of the charge of the individual cylinders, which in turn makes possible a clear reduction of the emission of pollutants of the internal combustion engine.
The present invention provides for an air mass signal representing an air mass flow to be processed in a nonlinear manner, the nonlinear processing preferably already occurring within the sensor. Since no information exists in the air mass sensor about the operating state of the internal combustion engine with respect to speed and load, no characteristics map can be stored in the air mass sensor itself, which could be addressed via these variables known in the engine control unit. The present invention therefore provides for the use of a correction characteristics map internal to the sensor, which is addressed via variables that are obtained from the raw signal of the sensor itself following an appropriate frequency filtering. For this purpose, empirically known, nonlinear characteristics of the sensor geometry, particularly of a bypass channel, can be utilized. This procedure allows one to dispense with painstaking transformation methods such as e.g. a Fourier transform.
A decisive advantage over an exclusive use of a correction characteristics map in the control unit lies in the fact that all relevant influence variables are taken into account. In the control unit of the internal combustion engine, by contrast, in addition to speed and load, there are in part also new pulsation-determined parameters such as e.g. camshaft settings, which do not enter into the characteristics map addressing of a characteristics map stored in an engine control unit. In the case of strong pulsations, these parameters result in errors in the air mass signal that cannot be compensated.
In an advantageous, previously unknown manner, it is possible to correct false indications that cannot be compensated, which allows for a significantly more precise detection of the charge of the cylinders of the internal combustion engine with the air mass required for combustion. Compared to previously used characteristic curve and characteristics map concepts, the method provided according to the present invention not only takes into account the current signal state of the flow sensor element of an air mass flow sensor, for example, but also its temporally preceding values.
An almost complete error-correction may be achieved simply by frequency-filtering the raw signal. Following the frequency filtering of the raw signal, the obtained signals are smoothed and used to address a characteristics map. The values of the respectively addressed characteristics maps are added to the raw signal. In this manner it is possible individually to correct false indications in the dependence on the pulsation frequency, the pulsation amplitude and the average air mass flow (which corresponds to the amplitude of the frequency 0). Depending on the justifiable expense and the required compensation ability, the size of the characteristics map and of the frequency filters used may be reduced. Thus it is already possible to achieve an effective pulsation correction with the aid of transfer functions. A particularly simple possibility for frequency filtering is provided by a low-pass and a high-pass filter.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a pulsation correction by non-linear characteristic curve distortion.
FIG. 2 a compensation circuit for error correction by signal filterings.
FIGS. 3.1 to 3 . 4 show pulsation errors of an air mass flow sensor sample at a frequency of f =58 Hz.
FIGS. 4.1 to 4 . 4 show pulsation errors of an air mass flow sensor sample at a pulsation frequency of f=145 Hz.
FIG. 5.1 shows frequency response characteristics of a low-pass and of a high-pass filter.
FIG. 5.2 shows frequency response characteristics of a low-pass, a band-pass and a high-pass filter.
FIG. 6 shows a block diagram of an analog compensation circuit having multipliers, adders as well as filter stages.
FIG. 7 shows a representation of a plug sensor extending into a measuring tube.
DETAILED DESCRIPTION
FIG. 1 shows a pulsation correction by non-linear characteristic curve distortion. In the non-linear characteristic curve optimization, the characteristic curve for converting signal voltages U A into air mass flows m is distorted in such a way that false pulsation indications are at least partially corrected and pulsation-free static flows are likewise indicated as correctly as possible. In the characteristic curve represented in FIG. 1 , the characteristic curve pattern a is changed by a modified characteristic curve pattern b. A constant signal voltage U 1 is converted into an associated corrected air mass signal m 1 . If pulsations of the signal voltage U A occur, given by U max (maximum signal voltage) and U min (minimum signal voltage), then, depending on the specific sensor properties, an excess indication may result for example. In the case of U max , an inference is made to a maximum air mass flow m max ; while in the case of the minimum of the pulsation at U min of the signal voltage, a minimum air mass flow m min is inferred. The air mass flow signal generated for signal voltage U A for value U min may now be converted into an air mass flow m both on original characteristic curve a as well as on modified characteristic curve b. In case of the correlation via the original characteristic curve a, m min (a) is inferred from U min . If b is read off from the modified characteristic curve b, then air mass flow m min (b) results for the minimum signal voltage U min . In the case of pulsations having reverse flow components, a relative diminished indication may be generated by modifying the characteristic curve and thus the false indication—correlation via the original characteristic curve a—may be compensated. By this method explained in connection with FIG. 1 , however, it is possible to compensate for false indications only incompletely since these also depend on the average air mass flow, on the pulsation amplitude, i.e. the difference between U max and U min , as well as on the pulsation frequency.
FIG. 2 shows a compensation circuit for error correction by signal filtering.
A nearly complete error correction may be achieved by the compensation circuit shown in FIG. 2 . Reference numeral 10 indicates the signal input, while reference numeral 11 marks the signal output. The signal entering at signal input 10 is supplied to a multiple frequency filter 12 and parallel to an adder 17 . Multiple frequency filter 12 comprises, for example, a low-pass filter 13 , a high-pass filter 14 as well as a band-pass filter 15 , which can optionally have a smoothing function connected in the outgoing circuit. The signals filtered by multiple frequency filter 12 are smoothed and used for addressing a correction characteristics map 16 . Correction characteristics map 16 is constructed as an m x n matrix. The frequency components f 1 , f 2 , . . . f n are written into addresses 1 , 2 , 3 , . . . m of correction characteristics map 16 and in the addition are added to the raw signal applied at signal input 10 . This makes it possible individually to correct false indications as a function of the pulsation frequency, the pulsation amplitude and the average air mass flow. The average air mass flow corresponds to the amplitude for frequency 0, i.e. of the low-pass output. FIG. 2 shows the most general possibility for implementing a compensation circuit for error correction by signal filtering. Depending on the justifiable expenditure and the required compensation ability, the size of correction characteristics map 16 and the size of multiple frequency filter 12 may be reduced. An effective pulsation correction can already be implemented, for example, by the transfer functions shown in FIGS. 5.1 and 5 . 2 . The representation of the sequence of FIGS. 3.1 , 3 . 2 , 3 . 3 and 3 . 4 shows pulsation errors of an air mass flow sensor pattern, which were recorded at a standard frequency of e.g. f=58 Hz. Reference numeral 21 indicates a first air mass flow of e.g. 10 kg/h, reference numeral 22 a second air mass flow of e.g. 30 kg/h, reference numeral 23 a third air mass flow of e.g. 60 kg/h, and reference numeral 24 a fourth air mass flow of e.g. 90 kg/h, while reference numeral 25 indicates the pulsation amplitude.
FIGS. 3.1 , 3 . 2 , 3 . 3 and 3 . 4 each show in the upper curve the pattern of an original air mass flow sensor signal as well as in the lower curve a signal corrected by the compensation circuit shown in FIG. 3 .
For first air mass flow 21 shown in FIG. 3.1 , a significant reduction of the error in the order of 5% may be achieved by frequency filtering the signal using the compensation circuit in accordance with FIG. 2 , while the sensor signal at a rising pulsation amplitude 25 may be faulty by up to 30%.
In FIG. 3.2 , the original air mass flow sensor signal for second air mass flow 22 of 30 kg/h is plotted against pulsation frequency 25 . With increasing pulsation frequency, the original signal takes on a steadily rising pattern, and at greater pulsation amplitudes 25 has errors that are greater than 40% and thus unusable. In the lower curve path in FIG. 3.2 , a signal corrected by the evaluation circuit according to FIG. 2 is entered, which still is 7% faulty. FIG. 3.3 shows the signal pattern of the original sensor signal for a third air mass flow of 60 kg/h. With the rise of pulsation amplitude 25 , the original air mass flow sensor signal is 25% faulty, while the signal filtered by the compensation circuit according to FIG. 2 shows an error in the order of 10%.
FIG. 3.4 shows the original air mass flow sensor signal for the fourth air mass flow of approx. 90 kg/h, which at a rising pulsation amplitude has an error in the order of 20%. In contrast, the signal filtered and smoothed by the compensation circuit according to FIG. 2 shows a significant error of between 2 and 8% only starting at a pulsation amplitude of 0.6.
The representations of FIGS. 4.1 , 4 . 2 , 4 . 3 and 4 . 4 show the air mass flows 21 , 22 , 23 and 24 at a second frequency 30 of f 2 =145 Hz or the signal resulting from these plotted against pulsation amplitude 25 .
As emerges from a comparison of the two curve patterns shown in FIG. 4.1 , with a rising pulsation amplitude 25 , the original signal of the air mass flow sensor represented by a bolded line has a sharply increasing error in the order of between 20 and 30%. By contrast, with an increasing pulsation duration, the signal, represented by a thinner line, which is filtered and smoothed by the compensation circuit according to the representation in FIG. 2 , only has an error of approximately 10%.
The situation is similar for the second air mass flow 22 (30 kg/h). With an increasing pulsation amplitude, the signal originally produced by the air mass flow sensor is in the order of beyond 30%, while the signal filtered and smoothed by the compensation circuit according to FIG. 2 has an error in the order of between 10 and 15% even at pulsation amplitudes of>2.5.
FIG. 4.3 shows the errors of the original signal pattern of the air mass flow sensor as well as the pattern of a signal filtered and smoothed by the compensation circuit according to the representation in FIG. 2 for a third air mass flow of approximately 60 kg/h. At pulsation amplitudes 25 , which are>1, the original signal generated by the air mass flow sensor are faulty at 30% and are thus no longer usable. By contrast, the signal filtered and smoothed by the compensation circuit according to the representation in FIG. 2 has a maximum error of 12%, which at a pulsation amplitude 25 of 1.5 steadily falls to 5%.
FIG. 4.4 shows a comparison of the signal patterns of the signal originally generated by the air mass flow sensor, which for pulsation amplitudes 25 ≧1 has an error of more than 15%. By contrast, the signal of the pulsation amplitude≧1 plotted as a thin line and filtered and smoothed by the compensation circuit according to the representation in FIG. 2 has an error in the order of 5%.
FIG. 5.1 shows frequency response characteristics of filter components, which can be used within multiple frequency filter 12 according to the representation in FIG. 2 . In the representation according to FIG. 5.1 , the frequency response characteristics of a low-pass filter, a frequency response characteristic of a high-pass filter 32 as well as the frequency response characteristic of a flow bypass are represented for the most simple case. Measuring elements for measuring the air mass flow are normally integrated into a flow bypass. This is provided for aerodynamic reasons and keeps contaminants away from the measuring element. On the other hand, the bypass is also used for damping rapidly varying flow components, which include high frequency pulsations and turbulences. The geometry of bypass 33 on the one hand may be optimized with a view to minimum contamination and on the other hand with a view to pulsation damping.
The representation according to FIG. 5.3 shows the frequency response characteristics of a low-pass filter 31 , of high-pass filter 32 , of flow bypass 32 as well as a frequency response characteristic 34 of a band-pass filter. The frequency response characteristics of the representation in FIG. 5.2 correspond to a characteristics map dimension n=3 (cf. representation according to FIG. 2 , correction characteristics map 16 ) and reflect the characteristic of the exemplary circuit implemented there. If the second characteristics map dimension is reduced from m to m=2, then this corresponds to a correction that is a linear function of the amplitudes of the individual frequency ranges.
For this case, the function of the compensation circuit can be reproduced using an analog circuit shown in FIG. 6 .
FIG. 6 shows the block diagram of the analog compensation circuit. The multiplier, adder and filter stages are implemented by operational amplifiers.
Analogous to the representation according to FIG. 2 , the signal input of signal voltage U A is indicated by reference numeral 10 , while the signal output behind adder 17 is indicated by reference numeral 11 . Input signal U A is on the one hand fed directly to adder 14 , to which a constant voltage k is applied. On the other hand, input signal U A is fed to low-pass filter 13 , to high-pass filter 14 as well as to band-pass filter 15 . Low-pass filter 13 is followed by multiplier 41 (low-pass), to which in turn a constant voltage U 1 is applied. Band-pass filter 15 is followed by another multiplier 42 (band-pass), to which in turn a constant voltage U 2 is applied. High-pass filter 14 is followed by a blocking diode 44 as well as by a smoothing stage 45 . Smoothing stage 45 of high-pass filter 14 is followed by a third multiplier 43 (high-pass), to which in turn a constant voltage U 3 is applied. Constant voltages U 1 , U 2 , U 3 and k can be set by a voltage divider to between GND and U Ref =+5 V, where k corresponds to an offset, while voltages U 1 , U 2 and U 3 to the gradients of the characteristics map entries of correction characteristics map 16 , which takes the form of an m×n matrix.
Multipliers 41 , 42 and 43 used in compensation circuit 40 according to the representation in FIG. 6 can take the form of operational amplifiers.
With the aid of the analog compensation circuit 40 shown in FIG. 6 it is possible to obtain the compensated signal patterns represented by thin lines in FIGS. 3.1 through 3 . 4 for the first frequency f 1 (58 Hz), which are distinguished with respect to pulsation amplitude 25 by a significantly reduced error component in comparison to the original signal of the air mass flow sensor for air mass flows 21 , 22 , 23 , 24 . The components of the total pulsation error that grow in a linear manner with a growing pulsation amplitude 25 are significantly reduced by compensation circuit 40 as in the sequence of FIGS. 3.1 through 3 . 4 for the first frequency f 1 of 58 Hz as well as in the representation according to FIGS. 4.1 through 4 . 4 for the second frequency f 2 of 145 Hz.
If compensation circuit 40 shown in FIG. 6 is implemented in a digital manner, or if a digital circuit corresponding to it is integrated into an ASIC of a hot air mass flow sensor, then multipliers 41 , 42 and 43 may be omitted completely. In this case, the multiplication is replaced by a determination of the amplitudes of individual frequency ranges and the appropriate addressing of correction characteristics map 16 . This in turn makes it possible to increase the dimension m of correction characteristics map 16 further, which allows for a further reduction of the occurring pulsation errors.
The basic measurements represented in the sequences of FIGS. 3.1 through 3 . 4 and 4 . 1 through 4 . 4 provide the basis for voltages U 1 , U 2 , U 3 and k. The measurements may be carried out at a pulsation test stand. Supplementary measurement may be carried out at engine test stands for combustion engines in the course of the application work. The more basic measurements and supplementary measurements are available as individual measurements, the greater is the application range that compensation circuit 40 is able to cover, whether it takes an analog or a digital form or whether it is integrated into an ASIC.
For applications, in which no specifically adjusted pulsation correction is required or desired, the entire correction function can be switched off in that all correction variables in correction characteristics map 16 are set to the value 0. The representation according to FIG. 7 shows that a plug sensor 52 is inserted into a measuring tube 50 , which has a flow cross-section 51 . An electronics 55 is integrated into the body of plug sensor 52 . Further, plug sensor 52 receives a bypass 53 , into which a measuring element 54 is integrated. Measuring element 54 integrated into bypass 53 is connected to electronics 55 . The air mass flow flowing in measuring tube 50 is indicated by m. Bypass 53 is provided for aerodynamic reasons and is further used to keep contaminants away from measuring element 54 . On the other hand, bypass 53 can also be used to dampen rapidly varying flow components, including high frequency pulsations and turbulences.
LIST OF REFERENCE NUMERALS
a original characteristic curve
b modified characteristic curve
m air mass flow
m max maximum air mass flow
U 1 constant signal voltage U A
U pulsating signal voltage
U max maximum signal voltage U A
U min minimum signal voltage U A
m 1 air mass flow at u 1
m min (b) air mass flow at U min (characteristic curve region b)
m max (a) air mass flow at U max (characteristic curve region a)
10 signal input U A
11 signal output
12 multiple frequency filter
13 low-pass filter
14 high-pass filter
15 band-pass filter
16 correction characteristics map (m×n matrix)
17 adder
20 1 . frequency F 1 =58 Hz
21 1 . air mass flow 10 kg/h
22 2 . air mass flow 30 kg/h
23 3 . air mass flow 60 kg/h
24 4 . air mass flow 90 kg/h
25 pulsation amplitude
30 2 . frequency F 2 =145 Hz
31 frequency response characteristic of low-pass filter
32 frequency response characteristic of high-pass filter
33 frequency response characteristic of flow bypass 53
34 frequency response characteristic of band-pass filter
40 block diagram of compensation circuit
u 1 1st constant voltage
u 2 2nd constant voltage
U 3 3rd constant voltage
k 4th constant voltage
41 multiplier (low-pass)
42 multiplier (band-pass)
43 multiplier (high-pass)
44 blocking diode
45 smoothing stage
50 measuring tube
51 flow cross-section
52 plug sensor
53 bypass
54 measuring element
55 electronics | A method and a device for the pulsation correction of measured values of a flow device, which is used to measure pulsating gas flows in internal combustion engines. A raw signal of the flow sensor is fed to an adder of a compensation circuit. The raw signal is at the same time fed to a multiple frequency filter, which has at least one high-pass filter, at least one low-pass filter and at least one band-pass filter. The filtered signals are written into addresses of a correction characteristics map. The values stored in addresses are added to the raw signal by the adder. | 5 |
ORIGIN OF THE INVENTION
The invention described herein was made in the performance of work Under a U.S. Army contract No. W911QX-09-C-0069, and is subject to provisions of public law 96-517 (35 USC 202) in which the contractor has elected to retain title.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to dense, virtually pore free, sintered silicon nitride ceramic compositions having simultaneously high mechanical strength, high reliability (Weibull Modulus) and high fracture toughness.
2. Background Art
Silicon nitride ceramics are well known as materials capable of high strengths, high toughness values (relative to most ceramics), and high strength at temperatures above 1000° C. Silicon nitride ceramics also have high reliability relative to other ceramics, exhibited by a small variation of strengths when a large number of samples is tested. If the composition and microstructure are designed well, the material can be flaw tolerant. Strength variation and flaw tolerance are expressed by high Weibull modulus values. It is desirable to have high values for all three mentioned properties: strength, Weibull modulus and fracture toughness, and this has not been achieved simultaneously by prior art. It is also desirable to produce silicon nitride with these properties at a reasonable cost without the use of expensive densification techniques.
Silicon nitride with the above combination of properties would be very desirable for a variety of industrial applications where strength and reliability are important. Examples are cutting tools, ball bearings, dewatering paper segments, insulators for down-hole oil drilling, cam-roller followers or tappet shims, gun barrels, vehicle and personnel armor.
Silicon nitride toughness is a result of the material's inter-twining needle-like grain structure, which can hinder the crack extension in the material by bridging the crack with intercepting grains. It is well known to anyone familiar with silicon nitride that the toughness is influenced by the nature and amount of the sintering aids used in the ceramic, the developed microstructure (grain width and length distribution) as well as the de-bonding ease at the silicon nitride grain and its grain boundary interface. State of the art silicon nitride materials typically have a fracture toughness values in the 5-7 MPa·m 1/2 range, and can have strengths ranging from 600 MPa to over 1000 MPa. Typically, however a compromise has to be reached between the two, since high fracture toughness requires a well developed network of large, reinforcing elongated grains in the microstructure, which then become strength limiting for the material. Additionally, due to these issues, even when high strength material can be made, occasional low strength specimens are encountered, reducing reliability and Weibull modulus.
The difficulty in attaining a combination of properties mentioned above can be seen in the prior art.
Li et al. (U.S. Pat. No. 5,637,540) teach a manufacturing method for silicon nitride material with fracture toughness values from 8 to 9.2 MPa·m 1/2 , but report room temperature strengths between 650 and 866 MPa. The exact bar size is not reported. The invention further reports that the majority of fracture origins are long β-Si3N4 grains, reported to be approximately 28-40 μm in size. This disclosure teaches additions of at least two rare earth oxides in combination with SrO and metal carbides, that are densified to full density at above 1900° C., followed by an even higher temperature heat treatment.
Similarly, Li et al. (U.S. Pat. No. 5,449,649) show that while making silicon nitride with fracture toughness of 10.6 MPa·m 1/2 (example 3 in patent), this material's 4-point average bend strength is below 600 MPa.
Pujari (WIPO Patent Application WO 2008/080058) shows a single example of a silicon nitride material (coded N3 in application) with fracture toughness over 8.12 MPa·m 1/2 (measured using a non standard technique) with a strength of 841 MPa evaluated on MOR bars of unknown size but with length up to 12 mm. It is known that small bars have lower strength than larger ones. The same material composition processed for shorter times or different temperatures resulted in a stronger material but with toughness less than 6 MPa·m 1/2 . This clearly shows the difficulty in attaining both high strength and toughness simultaneously in silicon nitride. The teachings of the above disclosure are based on silicon nitride with simultaneous additions of La 2 O 3 , Al 2 O 3 , Nd 2 O 3 , AlN, TiC and TiO 2 , and the reinforcing grains are shown to be up to approximately 4 μm in size.
Quadir et al. (U.S. Pat. No. 5,030,599) teaches a method of manufacture of Si 3 N 4 by adding at least three rare earth oxide sintering aids in addition to alumina to silicon nitride. However, the resulting strengths of the materials were below 650 MPa, and fracture toughness was not reported.
Becher et al. (J. Am. Ceram. Soc., 91 [7] 2328-2336) have reported that hot pressed strengths of over 1000 MPa (on small, non-standard bars) can be obtained on silicon nitride with 8% additions of La 2 O 3 , Gd 2 O 3 or Lu 2 O 3 with 2% MgO additions. Weibull moduli were not reported in the paper, however based on the reported standard deviations and mean values, and by using Monte Carlo simulations, the Weibull modulus was most likely below 10 in all three tested materials. All three of these materials were measured to have a high long crack (R-curve) toughness (10 to 12 MPa·m 1/2 ). The toughness was not measured using any of the standard ASTM C1421 techniques, therefore values can not be compared to other materials. In the reported micrographs, the largest reinforcing grains in the materials were up to about 5 μm.
Satet et al (J. Am. Ceram. Soc., 88 [9] 2485-2490) reported mean strengths of silicon nitride (with RE 2 O 3 , MgO and SiO 2 additions, where RE=Sc; Lu; Yb; Y; Sm or La) from approximately 900 to 1050 MPa, but the toughness was from 5.5 to 7.0 MPa·m 1/2 (using a standard method). The reinforcing grain length was up to 8 μm.
SUMMARY OF THE INVENTION
The present invention provides silicon nitride materials with high strength, fracture toughness values, and Weibull moduli simultaneously, due to unique large grain reinforcing microstructures and well engineered grain boundary compositions. The invention demonstrates that, surprisingly and contrary to prior art, a silicon nitride material can be made which simultaneously has high strength above about 850-900 MPa, a Weibull above about 15 and high fracture toughness (above about 8 and 9 MPa·m 1/2 ), and has reinforcing grains longer than 5 μm, typically longer than 10 μm in the microstructure without compromising its properties and reliability ( FIG. 1 , comprising FIGS. 1A and 1B ). The product of this invention can be processed using a variety of densification methods, including gas-pressure sintering, hot pressing, hot isostatic pressing, but is not limited to these, and does not require multiple heat treatments for all of these features to be achieved.
According to one aspect of the invention, there is provided a silicon nitride dense body of at least 98% theoretical density and virtually pore free, consisting essentially of the following:
a. About 85-93 wt % of β-Si 3 N 4 ; b. With the remaining 5-15 wt % material, mostly contained within grain boundary phase, involving one or more selected rare earth atomic species in the total amount of about 4.0-12% (expressed as oxides) and about 0.5-3% total Mg, Ca, or Ba alkaline earth species (or mixtures thereof) expressed as oxides; c. With the at least about 1% of one of the rare earth species (as oxide) selected from the list 1, and the remaining amount to be added as oxide can be chosen from list 1 or 2: List 1: La, Gd, Ce, Sm, Nd, Pr, Yb, Eu List 2: Lu, Y and Er
According to another aspect of the present invention, there are provided processes for sintering the silicon nitride at temperatures ranging from about 1600° C. to about 1950° C. for a time from about 1 hour to about 8 hours, with these values being approximate and requiring adjustment for the furnace type and size used, as known to the persons knowledgeable in the art. The sintering is carried out in a nitrogen containing atmosphere with sufficient pressure to suppress Si 3 N 4 decomposition, and can be done by gas pressure sintering, hot pressing, hot isostatic pressing or pressureless sintering. This allows fabrication of materials with large shapes by hot pressing, or can be shaped by dry pressing, green machining or casting methods to near net shape and sintered. No additional post densification heat treatments are necessary to attain the combination of properties in this invention.
According to another aspect of the invention, the final microstructure of the material after tailoring a wide range of sintering cycles, contains evenly distributed elongated grains with lengths from about 5 μm to about 30-40 μm in size without substantially reducing the material strength.
According to the present invention, there is provided a silicon nitride ceramic body that has a fracture toughness greater than about 8 MPa·m 1/2 (by Chevron Notch technique), a four point bend strength of at least 900 MPa at room temperature, and a Weibull modulus of at least 15.
BRIEF DESCRIPTION OF THE DRAWINGS
The various embodiments, features and advances of the present invention will be understood more completely hereinafter as a result of a detailed description thereof in which reference will be made to the following drawings:
FIG. 1 , comprising FIGS. 1A and 1B , are respective microphotographs of the structure of the silicon nitride material having the inventive features hereof.
DETAILED DESCRIPTION OF THE EMBODIMENTS
Three requirements have to be met concurrently to produce a high room temperature strength, high Weibull modulus and high toughness silicon nitride material:
1. the material has to be virtually pore free; 2. the microstructure of the Si 3 N 4 needs to consist of interpenetrating elongated β-Si 3 N 4 grains of tailored size distribution, aided by the chemically tailored grain boundary phase, and 3. the grain boundary phase needs to allow relatively easy de-bonding along the β-Si 3 N 4 grains, allowing crack bridging and arresting to occur. If this de-bonding is not possible due to strong bonding between grains and the grain boundary phase, the cracks will travel indiscriminately through both without deflections, and strength and toughness will be low.
In general, the sintered body of the present invention is formed by sintering a composition comprising: 1) silicon nitride powder; and 2) at least one rare earth compound (preferably in form of an oxide—but not limited to this) from a selected list; and 3) at least one compound from the group of Mg, Ca or Ba, also preferably as an oxide, hydroxide, carbonate or similar.
In one embodiment of the material: 1) silicon nitride should be present from about 85 to about 93 wt %; 2) the total rare earth metals content (as oxides) should be about 4-12% and; 3) the total alkaline earths content (MgO+CaO+BaO) about 0.5-4 w %, calculated as starting powders. In addition, the rare earth metals need to contain at least about 1% of one of the rare earth species (as oxide) selected from the list 1, and the remaining amount to be added as oxide can be chosen from list 1 or 2:
List 1: La, Gd, Ce, Sm, Nd, Pr, Yb, Eu List 2: Lu, Y and Er
The low limit of silicon nitride content prevents serious degradation of material properties by increasing the amount of grain boundary phases, and the high limit allows the material to sinter to full density at practical temperatures, as the oxide additives act as sintering aids. The selection of the rare earth oxide additions is made as described to allow effective de-bonding between the β-Si 3 N 4 grains and the grain boundary. The powders mixed according to the above description, can be pressed into desired shapes and densified in nitrogen atmosphere in a gas pressure furnace using two levels of gas pressure at temperatures from about 1600° C. to about 1950° C. for about 1 to about 8 hours. Instead of gas pressure sintering, hot isostatic pressing, hot pressing or pressureless sintering can be used under similar conditions.
It has been found that any (rare earth) RE-oxide from List 1 (or their mixtures) with other additions, result in grain boundaries that easily de-bond along Si 3 N 4 grains.
Unexpectedly, the inventors hereof have found that rare earth oxide additions solely from list 2, in combination with MgO, form a grain boundary that bonds strongly with the silicon nitride grains, causing low fracture toughness as well as low strength. This was observed despite a well developed microstructure with elongated grains.
Even more surprisingly, the inventors have found that if the RE oxides from List 2 are combined with at least about 1 w % of oxides from list 1, the resulting grain-boundary phase de-bonding along the Si 3 N 4 grains occurs again, resulting in high fracture toughness.
Another unexpected result of this invention is that the strength and fracture toughness of the described compositions are very stable and do not change measurably if the sintering temperature is changed by as much as 150° C., in contrast to prior art and practice.
In this embodiment the material properties are as follows: characteristic strength greater than 850 MPa, fracture toughness (Chevron Notch) greater than about 7.5 MPa·m 1/2 and Weibull modulus greater than about 15. The microstructure of the materials consists of elongated Si 3 N 4 grains with the largest reinforcing grains ranging from about 5 to about 40 μm in length.
In a preferred embodiment of the material: 1) silicon nitride should be present from about 89 to about 95 wt %; 2) the total rare earth metals (as oxides) content should be about 4-10%; and 3) the total alkaline earths content (MgO+CaO+BaO) about 0.5-3 w %, calculated as starting powders. In addition, the rare earth metals need to contain at least about 0.5% of one of the rare earth species (as oxide) selected from the list 1, and the remaining amount to be added as oxide can be chosen from list 1 or 2:
List 1: La, Gd, Ce, Sm, Nd, Pr, Yb, Eu List 2: Lu, Y and Er
The low limits of silicon nitride content are there to prevent serious degradation of material properties by increasing the amount of grain boundary phases, and the high limits are to allow the material to sinter to full density at practical temperatures, as the oxide additives act as sintering aids. The selection of the rare earth oxide additions is made as described to allow effective de-bonding between the β-Si 3 N 4 grains and the grain boundary. The powders mixed according to the above description, can be pressed into desired shapes and densified in nitrogen atmosphere in a gas pressure furnace using two levels of gas pressure at temperatures from about 1700° C. to about 1950° C. for about 1-about 8 hours. Instead of gas pressure sintering, hot isostatic pressing, hot pressing or pressureless sintering can be used under similar conditions.
Grain boundary phases in the compositions of this invention, when cooled naturally after sintering, can be amorphous or crystalline, depending on the rare earth metal being used as a sintering aid. The degree of crystallinity of the grain boundary phases can be increased by post sintering heat treatments to improve high temperature properties of the material, but this is not necessary for the room temperature strength and toughness. High temperature properties may require optimized post heat treatment and this would not be a departure from the teachings of this invention.
It is evident that further optimization of properties can be achieved by modifying the composition ratios of the rare earths and alkaline earth compounds within the defined range, as well as the processing conditions, including potential post densification treatments, without departing from the invention.
It is also evident that the compositions of this invention can be obtained using different starting materials, without departing from the teachings of the invention. For instance, silicon nitride powder can be used as a starting material, but also Si powder can be used instead, followed by a nitriding step. Also, the sintering aids can be added as oxides, hydroxides, carbonate or similar compounds that will yield oxides after the sintering heat treatment. Additions can be made in a form of finely dispersed powders, or as metal salt solutions in water in some cases. Other combinations of compounds and other methods of applying them are also possible without deviating from the invention.
Since strength and fracture toughness can be measured using different sample sizes and different methods, which can not be directly compared, it is important to define measurement methods used in this invention. For strength evaluation, ASTM C1161 method with B size bars was used, with a 4 point loading with a 40/20 mm spans. Fracture toughness was measured using ASTM C1421 with Chevron Notch type A bars. Weibull moduli were calculated using maximum likelihood estimation methodology using a minimum of 15 broken bars, in most cases 30 bars. In addition Vickers hardness at a 5 kg·f load (HV5) was measured. Thermal conductivity of selected samples was measured using the laser flash method.
In the following examples, these raw powders were used:
Si 3 N 4 from Ube, SN-E10 grade with a specific surface area (SSA) of about 10 m 2 /g and oxygen content of about 1.5%
Rare earth oxide powders with 99.9% or higher purity:
Nd 2 O 3 powder with SSA of 9.5 m 2 /g
Er 2 O 3 powder 1 with SSA of 1 m 2 /g
Er 2 O 3 powder 2 with SSA of 5 m 2 /g
Sm 2 O 3 powder with 3 m 2 /g
Pr 2 O 3 powder with SSA 2.5 m 2 /g
CeO 2 powder with SSA 10 m 2 /g
La 2 O 3 powder with SSA 5 m 2 /g
Gd 2 O 3 powder with SSA 2.4 m 2 /g
Y 2 O 3 powder with SSA of 15 m 2 /g
Lu 2 O 3 with SSA 4 m 2 /g
MgO powder with SSA of 15 m 2 /g
Powders batches were mixed by weighing appropriate amounts of powders for the composition to be made and by dispersing them in alcohol in a ball mil. The powder slurry was ball milled for 16 hours using Si 3 N 4 milling media. The slurry was then poured out of the mill though a 325 mesh screen and was dried in a distillery set-up. Dried powder was screened though a 60 mesh nylon screen, and stored in a labeled plastic container.
EXAMPLES 1-8
Powders batches in Table 1 were mixed as described above. Batched powders from Table 1 were weighed and loaded in a hot press graphite die (10 cm×10 cm size). Graphite tooling was coated with BN slurry. Four different billets were stacked in one die and the die was loaded into a hot press. The hot press runs were performed in a flowing nitrogen atmosphere at maximum temperatures indicated in Table 2, and the applied pressure was 10.3 MPa (1500 psi). After the run was cooled, billets were separated from the tooling, and were cleaned. Density was measured by water displacement, and then the MOR bars and Chevron notch bars were made from the material to evaluate its properties. Table 2 shows the results of property measurements.
TABLE 1
Compositions
Composition Code
Si 3 N 4 (wt %)
REO
MgO (wt %)
PR8-2
90
8 (Pr 2 O 3 )
2
YB8-2
90
8 (Yb 2 O 3 )
2
SM8-2
90
8 (Sm 2 O 3 )
2
CE8-2
90
8 (CeO 2 )
2
TABLE 2
Max temp
Characteristic
Thermal
Exp.
Comp
(° C.)/
Strength
Kic
Conductivity
#
Code
30 min
(MPa)
Weibull
(MPa · m 1/2 )
(W/m · K)
1
PR8-2
1850
1030
16
9.3
46
2
YB8-2
1850
1048
9
9.3
52
3
SM8-2
1850
1020
31
9.6
54
4
CE8-2
1850
1107
22
9.8
46
5
PR8-2
1900
1012
16
12.8
55
6
YB8-2
1900
814
9
9.9
65
7
SM8-2
1900
1008
22
9.2
56
8
CE8-2
1900
1090
18
9.3
66
EXAMPLES 9-16
Powders batches in Table 3 were mixed as described earlier. Powders from Table 3 were weighed and loaded in a hot press graphite die (10 cm×10 cm size). Graphite tooling was coated with BN slurry. Four different billets were stacked in one die and the die was loaded into a hotpress. The hot press runs were performed in a flowing nitrogen atmosphere at maximum temperatures indicated in Table 4, and the applied pressure was 10.3 MPa (1500 psi). After the run was cooled, billets were separated from the tooling, they were cleaned. Density was measured by water displacement, and then the MOR bars and Chevron notch bars were made from the material to evaluate its properties. Table 4 shows the results of property measurements.
TABLE 3
Compositions
Composition Code
Si 3 N 4 (wt %)
REO
MgO (wt %)
GD8-2
90
8 (Gd2O3)
2
ER(1)8-2
90
8 (Er2O3 powder 1)
2
ND8-2
90
8 (Nd2O3)
2
ER(2)8-2
90
8 (Er2O3 powder 2)
2
Examples 9-12 show lower strength and fracture values for several compositions due to a short time at the 1800° C., which did not allow the desired microstructure to be developed in the material.
TABLE 4
Characteristic
Thermal
Exp.
Comp
Max temp
Strength
KiC
Cond.
#
Code
(° C.)
(MPa)
Weibull
(MPa · m 1/2 )
(W/m · K)
9*
GD8-2
1800/30 min
1051
12
7.5
46
10*
ER(1)8-2
1800/30 min
846
12
5.2
52
11*
ND8-2
1800/30 min
986
7.5
7.3
51
12*
ER(2)8-2
1800/30 min
918
22
5.7
45
13
GD8-2
1850/60 min
978
20
8.8
63
15
ND8-2
1850/60 min
979
20
9.5
60
16
ER(2)8-2
1850/60 min
894
15
8.2
67
EXAMPLES 17-20
Powder compositions made in Table 1 were dry-pressed in a 10×10 cm steel die, followed by isopressing after sealing the part in a plastic bag. The parts were then sintered in a hot isostatic gas pressure sintering furnace at 1850° C., with 2 hours at low nitrogen pressure 1400 KPa (200 psi) followed by 1 hour at 277 MPa (30 Kpsi) pressure. All the materials achieved densities of over 98% of theoretical density. Table 5 shows the properties measured on the material from this run.
TABLE 5
HIP run data
Ch.
Kic
Hard-
Exp.
Comp
Str
(MPa ·
ness
Density
#
Code
(MPa)
Weibull
m 1/2 )
(GPa)
(g/cm 3 )
17
PR8-2
888
26
8.2
15.1
3.312
18
YB8-2
865
15
8.1
15.1
3.362
19
SM8-2
926
29
8.1
14.9
3.323
20
CE8-2
917
22
8.2
14.7
3.319
Examples 17 to 20 demonstrate that two stage hot isostatic pressing techniques can be used to successfully densify the compositions of this invention with high strength, Weibull modulus and fracture toughness values. Further optimization and property improvement are possible by optimizing the run parameters as well as powder processing techniques, without deviations from the teachings of the invention.
EXAMPLES 21-31
Powder batches in Table 6 were mixed as described earlier. Powders from Table 6 were weighed and loaded in a hot press graphite die (10 cm×10 cm size). Graphite tooling was coated with BN slurry. Four different billets were stacked in one die and the die was loaded into a hotpress. The hotpress runs were performed in a flowing nitrogen atmosphere at a maximum temperatures indicated in Table 7, and the applied pressure was 10.3 MPa (1500 psi). After the run was cooled, billets were separated from the tooling, they were cleaned. Density was measured by water displacement, and then the MOR bars and Chevron notch bars were made from the material to evaluate its properties. Table 7 shows the results of property measurements.
TABLE 6
Compositions
Composition Code
Si 3 N 4 (wt %)
REO
MgO (wt %)
LA8-2
90
8 (La 2 O 3 )
2
GD8-2
90
8 (Gd 2 O 3 )
2
Y8-2
90
8 (Y 2 O 3 )
2
LU8-2
90
8 (Lu 2 O 3 )
2
In Table 7, examples 23, 24, 27, 28 and 31 are comparative examples showing that additions of solely Y 2 O 3 or Lu 2 O 3 with MgO result in materials with low fracture toughness and low strength. It should also be noticed that the strength of both compositions (Y8-2 and LU8-2) decreases when the peak temperature is increased, due to grain growth. Strong bonding between the β-Si 3 N 4 grains and the grain boundary phases is responsible for this behavior, based on crack extension paths observed in these materials. This is a result of the distribution of La and Y cation species along the grain boundaries, thereby effecting the de-bonding.
More importantly, Table 7 shows that all examples with La and Gd additives result in very strong, reliable and very tough materials, and that the these properties are not substantially affected by the processing temperature even though different by 125° C., which is surprising. These additives, in combination with MgO form grain boundary phases that allow easy de-bonding along the elongated β-Si 3 N 4 grains. Also, in all these materials, the resulting microstructure contains large reinforcing grains from about 5 to about 40 μM in length.
TABLE 7
Exp.
Comp
Max temp
Ch. Str
KiC
Hardness
Debonding
#
Code
(° C.)/2 hrs
(MPa)
Weibull
(MPa · m 1/2 )
(GPa)
observed
21
LA8-2
1825
987
26
9.1
15
Yes
22
GD8-2
1825
974
21
9.2
15
Yes
23*
Y8-2
1825
765
7.5
6.8
15
Poor
24*
LU8-2
1825
701
4.7
4.6
15.4
Poor
25
LA8-2
1875
1005
18
9.0
15.6
Yes
26
GD8-2
1875
1001
22
9.0
16.0
Yes
27*
Y8-2
1875
634
9.2
4.9
16.3
Poor
28*
LU8-2
1875
688
8.7
4.5
16.2
Poor
29
LA8-2
1750
1011
16.1
7.6
—
Yes
30
GD8-2
1750
1022
16.8
8.5
—
Yes
31*
LU8-2
1750
704
15.7
4.2
—
Poor
EXAMPLES 31-37
Powders batched in Table 8 were mixed as described earlier. Powders from Table 8 were weighed and loaded in a hot press graphite die (10 cm×10 cm size). Graphite tooling was coated with BN slurry. Four different billets were stacked in one die and the die was loaded into a hotpress. The hot press runs were performed in a flowing nitrogen atmosphere at a maximum temperature indicated in Table 9, and the applied pressure was 10.3 MPa (1500 psi). After the run was cooled, billets were separated from the tooling, and they were cleaned. Density was measured by water displacement, and then the MOR bars and Chevron notch bars were made from the material to evaluate its properties. Table 9 shows the results of property measurements.
TABLE 8
Compositions
Composition Code
Si 3 N 4 (wt %)
REO %
MgO (wt %)
LALU44-2
90
4 (La 2 O 3 )
2
4 (Lu 2 O 3 )
CE8-2
90
8 (CeO 2 )
2
ND-2
90
8 (Nd 2 O 3 )
2
CELU8-2
90
4 (CeO 2 )
2
4 (Lu 2 O 3 )
Table 9 shows that all additives in Table 8 result in very strong, reliable and tough materials, and that these properties are not affected by the processing temperature even though different by 125° C., which is surprising.
Additionally, when Yttrium and Lutetium oxide additives (which on their own result in low toughness and strength materials) are combined with Lanthanum or Cerium additives, the toughness is restored, as well as strength and Weibull moduli. In all cases, the de-bonding between the grains and grain boundary phase is observed. This is also an unexpected result of this invention.
TABLE 9
Exp.
Comp
Max temp
Ch. Str
KiC
Hardness
Debonding
#
Code
(° C.)/2 hrs
(MPa)
Weibull
(MPa · m 1/2 )
(GPa)
observed
31
LALU44-2
1800
1069
18.7
9.7
15.5
Yes
32
LALU44-2
1750
1034
15.7
8.4
yes
33
ND-2
1800
955
15
8.5
15.5
Yes
34
CELU8-2
1800
1001
15.1
9
15.5
Yes
35
LALU44-2
1875
1007
15
9.1
15.5
Yes
36
ND-2
1875
971
15.5
9.4
15.6
Yes
37
CELU8-2
1875
936
16
9.1
15.5
Yes
EXAMPLES 38-45
Powder batches in Table 10 were mixed as described earlier.
For examples 38-41, powders from Table 10 were weighed and loaded in a hot press graphite die (10 cm×10 cm size). Graphite tooling was coated with BN slurry. Four different billets were stacked in one die and the die was loaded into a hot press. The hot press runs were performed in a flowing nitrogen atmosphere at a maximum temperature indicated in Table 11, and the applied pressure was 1500 psi. After the run was cooled, billets were separated from the tooling, and they were cleaned. Density was measured by water displacement, and then the MOR bars and Chevron notch bars were made from the material to evaluate its properties. Table 11 shows the results of property measurements.
For examples 42-45, powders from Table 10 were weighed, pressed in a steel die to form a 100×100×15 mm pre-form, followed by sealing in a bag and isopressing at 140 MPa. Parts were removed from the bags and placed in a graphite crucible with sacrificial packing powder. Parts were heated in nitrogen atmosphere (@ 700 KPa) to a maximum temperature (Table 10) and held there for 3 hrs. Gas pressure was then increased to 10.3 MPa for 2 hrs, followed by cooling. Pressure was released at room temperature and the parts removed and cleaned. Density was measured by water displacement, and then the MOR bars and Chevron notch bars were made from the material to evaluate its properties. Table 11 shows the results of property measurements.
TABLE 10
Compositions
Composition Code
Si 3 N 4 (wt %)
La 2 O 3 %
MgO (wt %)
LA4-.5
95.5
4
0.5
LA4-2
94
4
2
LA6-1
93
6
1
LA4-1
95
4
1
Table 11 shows that all additives in Table 10 result in very strong, reliable and tough materials processed both by hot pressing and by gas pressure sintering. Examples 42-45 showed a lightly lower strength in gas pressure sintering, but this can be improved by slight changes in processing conditions that would not deviate from the teachings of the invention. Examples 38-43 show that ratios of La and Mg additions can be modified while retaining the material properties. It is clear to any one knowledgeable in the art that additional improvements to the reported properties can be achieved by further optimization of compositions and processing of these material without departing from the teaching of the invention.
TABLE 11
Exp.
Comp
Max temp
Ch. Str
KiC
Debonding
#
Code
(° C.) hrs
Density
(MPa)
Weibull
(MPa · m 1/2 )
observed
38
LA4-.5
1800
>99%
863
10.9
8.6
Yes
39
LA4-2
1800
>99
977
20.9
8.7
Yes
40
LA6-1
1800
>99
870
25.5
7.7
Yes
41
LA4-1
1800
>99
880
31.5
8.7
Yes
42
LA4-.5
1875
99
840
Yes
43
LA4-2
1875
>99
849
19.9
8.7
Yes
44
LA6-1
1875
99
840
18
8.5
Yes
45
LA4-1
1875
99
855
15.5
8.4
Yes
EXAMPLES 46-49
Powder batches in Table 12 were mixed as described earlier.
Powders from Table 12 were weighed and loaded in a hot press graphite die (10 cm×10 cm size). Graphite tooling was coated with BN slurry. Four different billets were stacked in one die and the die was loaded into a hot press. The hot press runs were performed in a flowing nitrogen atmosphere at a maximum temperature indicated in Table 11, and the applied pressure was 1500 psi. After the run was cooled, billets were separated from the tooling, and they were cleaned. Density was measured by water displacement, and then the MOR bars and Chevron notch bars were made from the material to evaluate its properties. Table 11 shows the results of property measurements.
For examples 42-45, powders from Table 10 were weighed, pressed in a steel die to form a 100×100×15 mm pre-form, followed by sealing in a bag and isopressing at 140 MPa. Parts were removed from the bags and placed in a graphite crucible with sacrificial packing powder. Parts were heated in nitrogen atmosphere (@ 700 KPa) to a maximum temperature (Table 10) and held there for 3 hrs. Gas pressure was then increased to 10.3 MPa for 2 hrs, followed by cooling. Pressure was released at room temperature and the parts removed and cleaned. Density was measured by water displacement, and then the MOR bars and Chevron notch bars were made from the material to evaluate its properties. Table 11 shows the results of property measurements.
TABLE 12
Compositions
Composition
Code
Si 3 N 4 (wt %)
La 2 O 3 %
Lu 2 O 3
Y 2 O 3
MgO (wt %)
LALU13-0.5
95.5
1
3
0
0.5
LALU26-2
90
2
6
0
2
LAY13-2
94
1
0
3
2
LA16-1
92
1
0
6
1
Table 12 shows that all additives in Table 12 result in very strong, reliable and tough materials. Examples 46-49 additionally show that additions of only 1% of La 2 O 3 to a range of compositions with Lu 2 O 3 and Y 2 O 3 (which on their own would have a low strength and toughness) considerably improves their properties. It is clear to any one knowledgeable in the art that additional improvements to the reported properties can be achieved by further optimization of compositions and processing of these material without departing from the basic ideas and bounds of the invention.
TABLE 12
Exp.
Comp
Max temp
Ch. Str
Kic
Hardenss
Debonding
#
Code
(° C.) hrs
Density
(MPa)
Weibull
(MPa · m 1/2 )
(GPa)
observed
Hot Pressing
46
LALU13-0.5
1800
>99%
991
13
8.1
15.5
Yes
47
LALU26-2
1800
>99
1004
15.9
9.2
15.4
Yes
48
LAY13-2
1800
>99
1010
26
9.1
15.3
Yes
49
LA16-1
1800
>99
977
20
9.6
15.5
yes
Having disclosed various and preferred embodiments of the invention herein, it being understood that the numerous examples described are not exhaustive representations of the methods and results having the features deemed to be within the scope of the invention herein, what we claim is the following: | Silicon nitride materials with high strength, fracture toughness values, and Weibull moduli simultaneously, due to unique large grain reinforcing microstructures and well engineered grain boundary compositions. The invention demonstrates that, surprisingly and contrary to prior art, a silicon nitride material can be made which simultaneously has high strength above about 850-900 MPa, a Weibull above about 15 and high fracture toughness (above about 8 and 9 MPa·m 1/2 ), and has reinforcing grains longer than 5 μm, typically longer than 10 μm in the microstructure without compromising its properties and reliability. The product of this invention can be processed using a variety of densification methods, including gas-pressure sintering, hot pressing, hot isostatic pressing, but is not limited to these, and does not require multiple heat treatments for all of these features to be achieved. | 2 |
This is a division of application Ser. No. 74,188, filed Sept. 10, 1979.
SILYLATED POLYETHERS
The present invention relates to silylated polyethers, and more particularly to a process for preparing silylated polyethers. Also, this invention relates to textile materials coated with silylated polyethers and to a process for coating the same.
BACKGROUND OF INVENTION
Heretofore textile materials have been treated with compositions containing a hydroxyl terminated organopolysiloxane, a crosslinking agent and a catalyst to impart a soft silky durable hand thereto. (See U.S. Pat. Nos. 3,876,459 to Burrill and 3,770,489 to Richardson.) Although treatment with these organpolysiloxanes has been very effective for the intended purpose, it has also imparted certain undesirable properties to the treated materials. For example, textile materials treated with organopolysiloxanes tend to soil more readily. Moreover, organopolysiloxanes have a tendency to impart hydrophobic properties to textile materials treated therewith, which in turn decreases the comfort of the material. Furthermore, organopolysiloxanes are generally applied to textile materials in the form of emulsions and these emulsions have a tendency to separate during application, thereby resulting in a non-uniform coating. When these coated textile materials are then subjected to further treatment, such as dyeing or printing, the uneven distribution of organpolysiloxanes on the surface of the textile materials interferes with the print and dye quality of the material. Another disadvantage of organopolysiloxanes is that they generally require more than one component, and once the components have been mixed, the resultant composition is of limited stability.
Silicon containing materials which have been used to impart soil-repellent and soil-release properties to textile materials are described in U.S. Pat. Nos. 3,716,517 and 3,716,518 to Pittman et al. These silicon containing materials are prepared by copolymerizing at least one monomer capable of imparting oleophobic properties with at least one monomer capable of imparting hydrophilic properties. The oleophobic monomer is a silane which contains a terminal perfluoroalkyl group of from 3 to 18 perfluorinated carbon atoms. The hydrophilic monomer is a silane which contains two or more alkylene oxide groups in which the alkylene groups contain from 2 to 6 carbon atoms. These hydrophilic monomers are prepared by converting a monoetherified polyalkyleneoxy glycol to the corresponding allyl ether by reacting with allyl bromide in the presence of a base and thereafter reacting the intermediate reaction product with a silane containing hydrogen in the presence of a platinum catalyst. Where it is desired to produce monomers containing an ester linkage, the monoetherified polyethyleneoxy glycol is esterified with acryloyl chloride and then a hydrogen containing silane and platinum catalyst is added to the resultant intermediate.
In preparing the hydrophilic monomers described above, one essential ingredient is terminally unsaturated polyethers which are not readily available in commercial quantities. These terminally unsaturated polyethers may be prepared by reacting monoetherified polyalkyleneoxy glycols with allyl chloride. Furthermore, the silicon compounds described by Pittman et al, contain an ester group, whereas the silylated polyethers of the present invention contain amine or ester-amide or ester-ammonium or diester linkages.
Therefore, one of the advantages of this invention is that the silylated polyethers of this invention use material which are readily available such as polyoxyalkylene glycols and aminofunctional silanes. Another advantage of the silylated polyethers of this invention is that these silylated polyethers will crosslink to form hydrophilic coatings on textile materials treated therewith. The hydrophilic property improves the comfort of textile materials by wicking away body perspiration. Furthermore the silylated polyethers of this invention impart softness to textile materials treated therewith which offset the harsh hand imparted to textile materials treated with aminoplast resins. Also, it has been found that the silylated polyethers of this invention will extend the aminoplast resins and in certain applications may replace the aminoplast resins.
Therefore, it is an object of this invention to provide silylated polyethers. Another object of this invention is to provide silylated polyethers which may be applied to textile materials to impart a soft silky hand and good resistance to soil redeposition. Still another object of this invention is to provide silylated polyethers which may be applied to textile materials to impart hydrophilic properties thereto. A further object of this invention is to provide silylated polyethers which are water soluble and will not separate before and/or during application to textile materials. A still further object of this invention is to provide a single component, water soluble, stable silicon containing composition for treating textile materials.
SUMMARY OF INVENTION
The foregoing objects and others which will become apparent from the following description are accomplished in accordance with this invention, generally speaking, by providing silylated polyethers having the general formula ##STR1## wherein at least one R is selected from the group consisting of an --NH radical, an ammonium radical or a radical of the formula ##STR2## in which the radicals are linked to the polyether through an ester, amine, amide or ammonium radical and the remaining R groups are selected from hydrocarbonoxy radicals having up to 18 carbon atoms, hydroxyl radicals or a radical of the formula ##STR3## R 1 is a divalent hydrocarbon radical selected from the group consisting of --(CH 2 ) y , --CH═CH--, or a cyclic radical selected from the group consisting of C 6 H 4 , C 6 H 8 and C 10 H 6 ; A is a silicon containing radical selected from the group consisting of cationic or anionic radicals of the formula ##STR4## and nonionic radicals of the formula ##STR5## wherein R 2 and R 3 which may be the same or different, are monovalent hydrocarbon radicals having from 1 to 18 carbon atoms, R 4 is an ionic radical linked to a silicon atom consisting of hydrogen, carbon, oxygen and nitrogen atoms selected from the formulas ##STR6## in which R 5 is a nonionic radical consisting of carbon, hydrogen, oxygen and nitrogen atoms selected from the formulas ##STR7## and when R is an --NH 6 radical, then R 5 may be a divalent hydrocarbon radical and R 6 is a radical having from 1 to 10 carbon atoms selected from the group consisting of a saturated divalent hydrocarbon radical, a divalent hydrocarbonoxy radical in which the oxygen is in the form of an ether linkage and an unsaturated divalent hydrocarbon radical in which the unsatisfied valences are linked to a silicon atom. The unsatisfied valences of A are satisified by R and when A is a divalent radical, the ratio of A to R is 1:2 and when R is cationic, then A must be anionic, and when R is anionic, then A must be cationic and when R is nonionic then A must be nonionic, a is a number of from 0 to 4, b, c and d are each numbers of from 0 to 1, the sum of b, c and d must be at least 1, and when b, c or d are 0, then R must be a hydroxyl or hydrocarbonoxy radical or a radical of the formula ##STR8## e is a number of from 0 to 2, n is 2, 3 or 4, x is a number of at least 1 and up to 600, preferably from 10 to 250 and y is a number of from 0 to 8. These silylated polyethers may be applied to textile materials to form a hydrophilic coating thereon.
DETAILED DESCRIPTION
Suitable examples of silicon containing radicals represented by A above are ##STR9##
The unsatisfied valences of the silicon atoms in the above formulas are satisfied by silicon-oxygen-silicon linkages.
Suitable examples of hydrocarbonoxy radicals represented by R having from 1 to 18 carbon atoms are methoxy, ethoxy, propoxy, butoxy, octoxy, dodecoxy and octadecoxy radicals. Examples of suitable radicals represented by R 1 are divalent hydrocarbon radicals having from 1 to 8 carbon atoms are methylene, ethylene, trimethylene, tetramethylene, pentamethylene, hexamethylene and octamethylene radicals. Examples of divalent cyclic radicals represented by R 1 are phenylene, naphthenylene and cyclohexenylene radicals.
Suitable examples of monovalent hydrocarbon radicals represented by R 2 and R 3 are alkyl radicals, e.g., methyl, ethyl, propyl, butyl, hexyl, octyl, decyl, dodecyl and octadecyl radicals; aryl radicals, e.g., the phenyl radical; alkaryl radicals, e.g., tolyl, xylyl and ethylphenyl radicals; cycloalkyl radicals, e.g., cyclobutyl, cyclohexyl, cyclodecyl radicals; aralkyl radicals, e.g., benzyl, 2-phenylethyl, 2-phenylpropyl.
Examples of suitable divalent radicals represented by R 6 are hydrocarbon radicals such as ethylene, trimethylene, hexamethylene, octamethylene; hydrocarbonoxy containing radicals of the formula
(C.sub.2 H.sub.4 O).sub.m (CH.sub.2).sub.z, (C.sub.3 H.sub.6 O).sub.m (CH.sub.2).sub.z and (C.sub.4 H.sub.8 O).sub.m (CH.sub.2).sub.z
where m is from 1 to 50, and z is a number of from 1 to 10, ethylene oxide, trimethylene oxide, tetramethylene oxide and polymers and copolymers thereof and alkylene radicals such as vinylene, propenylene, butenylene, hexenylene and the like.
The silylated polyethers of this invention may be prepared by several different techniques. Some of the techniques for preparing these silylated polyethers are described herein below.
One method for preparing the silylated polyethers is to react oxyalkylene glycols or copolymers thereof with a mono cyclic anhydride at a temperature of from 80° to 185° C. to form a half ester which is then reacted with an aminofunctional silane having at least 1 and up to 3 alkoxy groups per silicon atom at from 0° to 110° C.
The reaction described above may be further illustrated by the following equations: ##STR10##
A second method for preparing the silylated ethers of this invention is to react an aminofunctional silane with a mono cyclic anhydride at a temperature of from 25° to 110° C. to form a carboxylic acid functional silane and thereafter reacting the resultant silane with amine terminated oxyalkylene polymer or copolymers thereof at a temperature of from 0° to 110° C. This method is further illustrated by the following equations: ##STR11##
In the methods described above, if the reactants in equations (b) and (d) are heated up to about 115° C., the resultant product is an ammonium salt. When an amido linkage is desired, then the reactants are heated at temperatures above 115° C.; however, the by-product, water, will hydrolyze the alkoxy groups on the silicon atom, thereby resulting in the formation of a crosslinked network.
A third method for preparing silylated polyethers is to react an amine terminated oxyalkylene polymer or copolymers thereof with a cyclic anhydride to form a carboxylic acid functional polymer which is then reacted with an aminofunctional silane at a temperature of from 0° to 110° C. This method is further illustrated by the equations: ##STR12##
A fourth method for preparing the silylated polyethers of this invention is to react an oxyalkylene glycol or copolymers thereof with a cyclic anhydride and thereafter reacting the resultant carboxylic acid polymer with a haloalkylalkoxysilane in the presence of triethylamine at a temperature of from 80° to 150° C. ##STR13##
A fifth method for preparing silylated polyethers is to react an amine terminated oxyalkylene polymer or copolymers thereof with a haloalkylalkoxysilane and thereafter reacting the resultant product with a sodium alkoxide at a temperature of from about 80° to 150° C.
This method is illustrated by the following equations: ##STR14## wherein R and x are the same as above.
The silylated polyethers of this invention may also be prepared by substituting dicarboxylic acids having up to 10 carbon atoms for the cyclic anhydrides described above.
When dicarboxylic acids are used, it may be advantageous to employ an esterification catalyst such as titanates, alkali metal hydroxides and mineral acids.
Suitable examples of dicarboxylic acids which may be used are oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid and sebacic acid.
The oxyalkylene glycols and copolymers thereof which are used to make the compositions of this invention are well known in the art. These glycol polymers and copolymers may be illustrated by the following formula: ##STR15## where G is hydrogen or an alkyl radical having from 1 to 18 carbon atoms, in which at least one G must be hydrogen and n is 2, 3 or 4, x is a number of at least 1 and up to 600, preferably from 10 to 250. Generally, these polymers are made by the homopolymerization or copolymerization of ethylene oxide and propylene oxide using various alcohols as initiators. Examples of alcohol are glycerine, methanol, ethylene glycol, ethanol, t-butanol and the like.
Suitable examples of cyclic anhydrides that may be used to make the compositions of this invention are succinic anhydride, glutaconic anhydride, maleic anhydride, 1,2-cyclohexanedicarboxylic anhydride, 1-cyclohexene-1,2-dicarboxylic anhydride, 3-cyclohexene-1,2-dicarboxylic anhydride, 4-cyclohexene-1, 2 dicarboxylic anhydride, 1, 8-naphthalic acid anhydride and phthalic anhydride.
Suitable examples of aminofunctional silanes which may be used to prepare the compositions of this invention are beta-aminopropyltriethoxysilane, gamma-aminopropyltrimethoxysilane, methyl-beta-(aminoethyl)-gamma-aminopropyldimethoxysilane, omega-aminohexyltributoxysilane, beta-(aminoethoxy)propyltrimethoxysilane, beta-(aminoethoxy)hexyltriethoxysilane, beta-(aminopropoxy)butyltributoxysilane, ##STR16## and the like.
Examples of amine terminated oxyalkylene homopolymers and copolymers which may be used to prepare the compositions of this invention are those having the general formula ##STR17## wherein a, n and x are the same as above. It is preferred that at least one OC 3 H 6 group be present and that the amine group be linked to the OC 3 H 6 group. These polymers can be synthesized by effecting the amination of the corresponding oxyalkylene homopolymer or copolymer having terminal haloalkyl groups. These haloalkyl terminated polymers may be prepared by reacting oxyalkylene glycol or copolymers thereof with a phosphorus trihalide.
The haloalkyl silanes that may be used in the preparation of the silylated polyethers may be represented by the formula ##STR18## wherein R 2 , R 3 and e are the same as above, R 7 is a divalent hydrocarbon radical having from 1 to 18 carbon atoms, and X is a halogen such as chlorine, bromine and iodine.
Suitable examples of divalent hydrocarbon radicals represented by R 7 are ethylene, trimethylene, tetramethylene, hexamethylene, octamethylene, dodecamethylene, hexadecamethylene and octadecamethylene radicals.
More specifically, suitable examples of haloalkysilanes that may be used are chloropropyltrimethoxysilane, chloropropylmethyldimethoxysilane, chloropropyldimethylethoxysilane, bromopropyltriethoxysilane, iodobutylmethyldimethoxysilane, bromobutylethyldimethoxysilane and the like.
A crosslinked network is formed by heating the ionic salts described above to form the corresponding amide and the water formed as a by-product, hydrolyzes the alkoxy group linked to the silicon atom to cause crosslinking thereof.
In the above reactions, the mole ratio of cyclic anhydride to amine or hydroxyl groups linked to the polyether or silane may be varied over a wide range. For example, the mole ratio of cyclic anhydride to amine or hydroxyl group may range from 0.17:1 to 1.25:1 with the preferred ratio of cyclic anhydride to amine or hydroxyl groups being from 0.33:1 to 1.1:1, with the proviso that at least one amine or hydroxyl group per molecule is reacted with the cyclic anhydride.
In the subsequent silylation of the polyethers, the mole ratio of the carboxylic acid radical formed from the reaction of the cyclic anhydride with the above amine or hydroxyl groups to the haloalkyl radicals linked to the silane or the amine groups linked to the silane or polyether may range from 0.17:1 to 1.25:1 with the proviso that at least one carboxylic acid radical per molecule is present for each amine group in order that an ammonium salt or the corresponding amide or the ester is formed.
The silylated polyethers of this invention can be applied to textile materials in admixture with other substances which have heretofore been used to impart certain properties to textile materials. Other substances which may be used in combination with the silylated polyethers are lubricating agents, agents which impart abrasion resistance to the treated fibers, materials which improve the fragrance of the treated materials, antistatic lubricants, fabric softeners, fire retardants, soil resistant materials and crease proofing agents. Examples of crease proofing agents are aminoplast resins such as urea-formaldehyde resins, melamine-formaldehyde resins, and dimethylol dihydroxy ethylene urea which may contain magnesium chloride and zinc nitrate as catalysts. Other crease-proofing resins are phenol-formaldehyde resins and hydroxyethyl methacrylate.
The silylated polyethers of this invention may be applied in concentrated form or as an aqueous solution or in the form of dispersions in water or in organic solvents such as di-n-butylether, aromatic hydrocarbons, and/or chlorinated hydrocarbons.
These silylated polyethers possess a variety of outstanding properties. By way of illustrations they can be prepared so that they are soluble in water. Also, they can be prepared so that they are water insoluble, but are easily emulsified or dispersed in water without the aid of an emulsifiying or dispersing agent.
The amount of silylated polyethers dissolved or dispersed in water may vary over a wide range. Generally, the amount of silylated polyether present in an aqueous solution or dispersion may range from about 0.25 to 99 percent, preferably from about 1 to 60 percent and more preferably from about 2 to 50 percent by weight based on the weight of the silylated polyether and solvent.
The silylated polyethers of this invention, and if desired other substances, may be applied to all textile materials, preferably organic textile materials on which organopolysiloxanes have been or could have been applied heretofore. Examples of such textile materials are wool, cotton, rayon, hemp, natural silk, polypropylene, polyethylene, polyester, polyurethane, polyamide, cellulose acetate, polyacrylonitrile fibers, and mixtures of such fibers. The textile materials may consist of staple fibers or monofilaments.
The silylated polyethers of this invention and other substances, if desired, may be applied to the textile materials by any means known in the art, such as by spraying, immersion, coating, calendering or by gliding the fibers across a base which has been saturated with the silylated polyethers of this invention and other materials, if desired.
Generally, the solids add-on is in the range of from 0.025 to 20 percent and preferably from about 0.05 to 10 percent, based on the weight of the original textile material.
After the textile material has been treated, it is dried at an elevated temperature, e.g., from about 50 to 200° C. for a brief period of time, e.g., from about 3 to 15 minutes.
The treated textile material should contain from about 0.025 to about 10 percent by weight on a dry basis of the cured composition of this invention.
Textile materials treated with the silylated polyethers of this invention possess all of the properties common to prior art textile materials, such as soft hand, with the additional property of being durably hydrophilic and soil resistant.
Specific embodiments of this invention are further illustrated in the following examples in which all parts are by weight unless otherwise specified.
EXAMPLE 1
A mixture containing about 500 parts (0.19 mole) of an oxyethylene-oxypropylene triol copolymer having a weight ratio of oxyethylene to oxypropylene of about 1 to 1 and a molecular weight of about 2600 and about 50 parts (0.5 mole) of succinic anhydride are heated in a nitrogen atmosphere for 6 hours at 100° C. and then the temperature is increased to 150° C. and heated for an additional 7 hours. A sample is withdrawn and analyzed by infrared analysis for the presence of anhydride groups. No anhydride groups are detected in the product. The reaction product is cooled to 60° C. and about 110.5 parts (0.5 mole of aminopropyltriethoxysilane are added to the product and mixed for two hours. Subsequent Nuclear magnetic Resonance and Infrared analyses indicate a product having a formula ##STR19## The product is a water soluble amber liquid. Water solutions of the polymer formed a friable rubber-like film upon evaporation.
EXAMPLE 2
A mixture containing about 2,000 parts (0.35 mole) of an oxyethylene-oxypropylene triol copolymer having a mole ratio of oxyethylene units to oxypropylene units of about 3.6 to 1 with a molecular weight of about 5,660 and about 106.1 parts (1.06 moles) of succinic anhydride are heated at about 175° C. for eighteen hours. The resultant product has a viscosity of 4,168 cs. at 25° C. Nuclear Magnetic Resonance analysis shows a mole ratio of the functional groups as follows:
______________________________________Functional Group Mole Ratio______________________________________C.sub.3 H.sub.6 O 1.0C.sub.2 H.sub.4 O 3.88______________________________________
The acid content is found to be about 0.58 milliequivalent of acid per gram while the theoretical value is 0.5 milliequivalent per gram. The product is represented by the formula ##STR20##
About 900 parts of the above product are mixed for 1 hour with about 90.1 parts aminopropyltriethoxysilane. A slight exotherm is observed. The resultant product is a dark straw colored liquid having a viscosity of 24,460 cs. at 25° C. It is water soluble and an aqueous solution of the polymer formed a friable rubber-like film when the water is allowed to evaporate at room temperature. The crosslinked product has the following formula in which the unsatisfied valences of the silicon atoms are satisfied by other silicon atoms through an oxygen linkage. ##STR21##
EXAMPLE 3
A mixture containing about 400 parts of polyoxyethylene diol having a molecular weight of 400 and 200 parts of succinic anhydride are heated to 175° C. with agitation. It is then cooled to 90° C. and a sample analyzed by Infrared. The analysis indicates a product having the formula ##STR22##
About 442 parts of 3-aminopropyltriethoxysilane are added to the product, heated to 90° C. for two hours and then cooled to room temperature. Nuclear Magnetic Resonance and Infrared analyses show a product having the formula ##STR23##
The product is a water soluble viscous amber colored liquid. An aqueous solution of the polymer formed a friable rubber-like film when the water is allowed to evaporate at room temperature. The resultant crosslinked film is insoluble in water.
EXAMPLE 4
A mixture containing 1,000 parts (0.38 mole) of an oxyethylene-oxypropylene triol copolymer having a molecular weight of about 2600, with a weight ratio of oxyethylene to oxypropylene of about 1 to 1, and about 150.3 parts (1.5 moles) of succinic anhydride are heated to 170° C. for twelve hours. The resultant product is cooled to room temperature, then about 166.5 parts (0.75 mole) of 2-amino ethyl-3-aminopropyltrimethoxysilane are added and mixed for one hour, during which time the temperature increases to 50° C. A straw-colored liquid is obtained which has a viscosity of 23,584 cs. at 25° C. Nuclear Magnetic Resonance and Infrared analyses show that the composition has the following formula ##STR24##
The product is water soluble and when the water is removed from the aqueous solution by evaporation, a friable rubber-like film is obtained.
EXAMPLE 5
A mixture containing about 650 parts (0.25 mole) of an oxyethylene-oxypropylene triol copolymer having a molecular weight of 2600 and about 25 parts, (0.25 mole) of succinic anhydride are heated to 170° C. The resultant product is cooled to room temperature and about 55.3 parts (0.25 mole) of aminopropyltriethoxysilane are added with agitation. A slight exotherm is observed. Subsequent analyses by Nuclear Magnetic Resonance and Infrared show a product having the general formula ##STR25## The product has a viscosity of 3,118 cs. at 25° C. and a pH of 7.57. An aqueous solution of the product cures to a gellatinous film when the water is allowed to evaporate at room temperature.
EXAMPLE 6
A mixture containing about 1300 parts (0.5 mole) of an oxyethylene-oxypropylene triol copolymer having a molecular weight of about 2600 and about 150 parts of succinic anhydride are heated in accordance with the procedure described in Example 2. The resultant product is cooled to room temperature and about 110.5 parts (0.5 mole) of aminopropyltriethoxysilane are added with agitation. A slight exotherm is observed.
Nuclear Magnetic Resonance and Infrared analyses show a product having the following formula ##STR26## The product is found to have an acid equivalent of 0.6 milliequivalent of acid per gram.
EXAMPLE 7
About 222 parts of aminopropyltriethoxysilane and about 100 parts of succinic anhydride are mixed together and the resulting exotherm heated the mixture to about 110° C. The mixture is agitated for 2 hours and then cooled to room temperature. A clear yellow liquid is obtained having a viscosity of 521.9 cs. and an acid content of 2.7 milliequivalents per gram (theoretical 3.1) Infrared analysis shows that the succinic anhydride has reacted and that a silane containing a carboxylic acid group is formed.
About 75 parts of the resultant product and 139.8 parts of an amine terminated polyether having the formula ##STR27## are mixed together.
The temperature of the reaction mixture increases to 50° C. The reactants are agitated for two hours and then cooled to ambient temperature. A clear yellow fluid is obtained having a viscosity of 764.7 cs. at 25° C. A portion of the composition is dissolved in water and then the water is evaporated in an oven at 182° C. A heterogenous film consisting of a liquid phase and a friable rubber is obtained indicating that all the polyether molecules are not silylated. The product consists of a mixture of unreacted amine terminated polyether and silylated polyethers of the formulas ##STR28##
EXAMPLE 8
About 100 parts of the silane containing the carboxylic acid groups prepared in accordance with the procedure of Example 7 and 93.6 parts of the amine terminated polyether of Example 7 are mixed together in a reaction vessel. The temperature of the reaction vessel increases to about 45° C. as a result of the exotherm. A yellow, slightly cloudy liquid having a viscosity of 5,039 cs. at 25° C. is obtained. A portion of the reaction mixture is dissolved in water and the water evaporated off in an oven at 172° C. A rubber-like film is obtained, indicating that silylation is complete. The resultant product is represented by the following formula ##STR29##
EXAMPLE 9
About 187.2 parts of the amine terminated polyether of Example 7 and 62 parts of succinic anhydride are mixed together in a reaction vessel. The temperature increases to about 110° C. as a result of the exotherm. A yellow liquid is obtained having a viscosity of 14,310 cs. at 25° C. and an acid content of 2.6 milliequivalents per gram. Infrared analysis shows that a carboxylic acid group is formed. About 124.6 parts of the resultant carboxylic acid containing polymer are mixed with about 69 parts of aminopropyltriethoxysilane and as a result of the exotherm, the temperature of the reactants increases to 75° C. A yellow liquie having a viscosity of 23,814 cs. at 25° l C. is obtained. A portion of the composition is dissolved in water and the water evaporated off in an oven at 172° C. A rubber-like film is obtained, which shows that silylation has occurred. The product is represented by the following formula ##STR30##
EXAMPLE 10
A mixture containing about 19.9 parts of 3-chloropropyl trimethoxysilane, 100 parts of methanol, and 200 parts of an amine terminated oxyethylene-oxypropylene copolymer of the formula ##STR31## are refluxed in a reaction vessel for four hours. After four hours, about 21.6 parts of a solution consisting of 25 percent sodium methoxide and 75 percent methanol are added. The reaction vessel is cooled to ambient temperature and the by-product sodium chloride removed by filtration. The volatile constitutents are then removed in vacuum. A clear yellow wax having a melting range of from 42°-45° C. and an elemental silicon content of 1.06 percent is obtained. The composition is represented by the formula ##STR32##
EXAMPLE 11
A mixture containing about 100.1 parts of succinic anhydride and 375 parts of a polyoxypropylene glycol having a molecular weight of 750 is heated to 170° C. in a reaction vessel and then cooled to 50° C. About 221 parts aminopropyltriethoxysilane are then added and agitated for two hours. A yellow liquid having a viscosity of 11,373 cs. at 25° C. is obtained. A portion of the product is added to water and the mixture readily separates into two layers. The water is evaporated off in an oven at 172° C. A friable-rubber film is obtained which shows that the polyether has been silylated.
EXAMPLE 12
A mixture containing about 106.1 parts of succinic anhydride and 2000 parts of oxyethylene-oxypropylene triol copolymer, having a molecular weight of 6360 and a weight ratio of oxyethylene to oxypropylene of 7 to 3 is heated at 175° C. for eighteen hours in a reaction vessel. The resultant product is a yellow liquid having a viscosity of 4,168 cs. at 25° C. and an acid content of 0.58 milliequivalent per gram (theoretical 0.5).
About 258.6 parts of the above product are mixed with 29.8 parts of chloropropyltrimethoxysilane, 15.2 parts of triethylamine and 100 parts of toluene and refluxed for nine hours. A white solid by-product is removed by filtration which is identified as triethylamine hydrochloride.
The volatiles are then vacuum stripped off, yielding a brown, taffy-like liquid having a viscosity of 29,347 cs. at 25° C. A portion of the resultant product is dissolved in water and the water evaporated off in an over at 172° C. A friable-rubber film is formed which shows that a silylated product is obtained.
EXAMPLE 13
The procedure of Example 1 is repeated except that 74 parts of phthalic anhydride are substituted for the succinic anhydride. An amber liquid having a viscosity of 17,887 cs. at 25° C. is obtained. The resultant product is represented by the following formula ##STR33##
When the product is hydrolyzed, a friable-rubber film is formed.
EXAMPLE 14
The procedure of Example 1 is repeated except that 19 parts of maleic anhydride is substituted for the succinic anhydride. An amber liquid having a viscosity of 84,470 cs. at 25° C. is obtained. The resultant product is represented by the formula ##STR34##
When the product is hydrolyzed, a friable-rubber film is obtained.
COMPARISON EXAMPLE V 1
The carboxylic acid containing oxyethylene-oxypropylene copolymers of Example 12 are dissolved in water and then the water is evaporated off at 172° C. In a similar experiment, the glycol functional oxyethylene-oxypropylene copolymers of Example 12 are dissolved in water and the water evaporated off at 172° C. In both experiments a liquid product is obtained. These experiments show that the polyether must be silylated in order to obtain a crosslinked network.
EXAMPLE 15
A textile fabric containing a mixture of Dacron and cotton (65/35) is treated with the silylated polyethers of this invention by dipping the fabric in aqueous solutions containing 0.7 percent by weight of the various compositions prepared in the Examples and 1.7 percent by weight of dimethyol dihydroxy ethylene urea in which the percent by weight is based on the total weight of the solution. The fabric is then dried for two minutes at 70° C. in a forced air oven. The hydrophilic properties of the fabric are evaluated in accordance with the procedure described in the AATCC Test Method 39-1977 "Wettability: Evaluation of". Each fabric is then laundered once and the properties reevaluated. Table I shows the results of these tests.
COMPARISON EXAMPLE V 2
A textile fabric containing a mixture of Dacron-cotton (65/35) is treated with an aqueous solution containing 1.7 percent of dimethyol dihydroxy ethylene urea in accordance with the procedure described in Example 15. The treated fabric has a harsh stiff hand. The results of the tests are shown in the following Table.
TABLE I______________________________________Wetting times, (sec.)Example 2 3No. Initial 1 Wash Washes Washes 4 Washes 5 Washes______________________________________1 4 5 7 7 9 112 4 5 7 7 84 4 7 10 12 14 2413 13 8 9 12 1314 8 7 10 11 11Compar-isonExample 10 11 -- -- --V.sub.2______________________________________
EXAMPLE 16
The procedure of Example 15 is repeated except that a Dacron fabric is treated with aqueous solutions containing 5 percent by weight based on the weight of the aqueous solutions of the compositions described in the Examples. The dimethyol dihydroxy ethylene urea is omitted from the aqueous solutions. The following table shows the results of these tests.
______________________________________ Initial Wetting TimeExample No. Wetting Time After 1 Wash______________________________________None 10 min. 10 min.7 2 sec. 35 sec.8 2 sec. 17 sec.10 6 sec. 20 sec.14 3 sec. 3 sec.______________________________________
The above table shows that each of the compositions impart hydrophilic properties to the treated fabric and after one wash have a soft, silky hand.
EXAMPLE 17
Other fabrics, including cotton, wool, nylon, and rayon are treated with the composition of Example 1 in accordance with the procedure described in Example 15. Fabrics having hydrophilic properties and a soft, silky hand are obtained. | A process for treating a textile material which comprises coating a textile material with a composition containing a silylated polyether and thereafter drying the coated material at an elevated temperature in the presence of atmospheric moisture. | 3 |
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