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CROSS REFERENCE OF RELATED APPLICATION
[0001] This is a U.S. National Stage under 35 U.S.C 371 of the International Application PCT/CN2014/000654, filed Jul. 07, 2014, which claims priority under 35 U.S.C. 119(a-d) to CN 201410249917.5, filed Jun. 6, 2014.
BACKGROUND OF THE PRESENT INVENTION
[0002] Field of Invention
[0003] The present invention relates to a technical field of ionic membranes, and more particularly to a zero polar distance ion exchange membrane and a preparation method thereof.
[0004] Description of Related Arts
[0005] In recent years, during the ion-exchange membrane chlor-alkali production, in order to achieve electrolysis under high current density, low cell voltage and high lye concentration for improving productivity and reducing power consumption, the key is to shorten the distance between the ion-exchange membrane and the electrode for reducing the cell voltage thereof, thereby achieving the practicality of the narrow polar distance type ion-exchange membrane electrolysis process. With the continuous progress of technology, the zero polar distance electrolytic cell has been widely applied, and however, when the distance between the electrodes is reduced to be less than 2 mm, due to tightly attachment between the membrane and the negative electrode, hydrogen bubbles attached to the membrane surface are hard to be released, thus a large amount of hydrogen bubbles are accumulated on the membrane surface which faces to the negative electrode. The bubbles blocks the current channel for reducing the effective electrolytic area of the membrane, which results in unevenly current distribution on the membrane surface, thus the local polarization is obviously increased. Therefore, the membrane resistance and the cell voltage are sharply increased, and the electrolysis power consumption is significantly improved.
[0006] To overcome the shortcomings caused by the bubble effect, and rapidly release the attached hydrogen bubbles from the membrane surface with small hydrophilicity, a modification method of a hydrophilic coating on the ion-exchange membrane surface is developed. After coating a multi-porous non-electrocatalytic activity non-electrode coating, through which gases and liquids are able to permeate, on the membrane surface, the hydrophilicity of the membrane surface is obviously increased, the anti-foaming ability are significantly improved. The ion exchange membrane with the modified hydrophilic coating is able to be tightly attached to the electrode, so as to greatly reduce the cell voltage. Currently, it is widely applied to the zero polar distance type ion exchange membrane electrolysis process. The hydrophilic coating modification process includes steps of mixing inorganic components with special adhesives, and then coating on the ion exchange membrane surface through an electrolytic deposition method or a particle embedding method. Patent applications CA2446448 and CA2444585 specifically introduced the coating process. However, the above modification method has significant effect, but relatively complex process. Moreover, during the electrolysis operation, because the ion exchange membrane is continuously scoured by the lye flow and goes through the continuous shock caused by the turbulence, the hydrophilic coating attached to the ion exchange membrane surface gradually falls off, thus the anti-foaming function is gradually reduced to be of no effect.
[0007] Patent application U.S. Pat. No. 4,502,931 proposed to process the ion exchange membrane surface with surface roughening modification through an ion etching method. However, the method is not easy to be implemented on a large scale, and has low anti-foaming ability. When the distance between electrodes is reduced to a certain degree, the cell voltage is still larger than 3.5 V, and the current efficiency is lower than 90%.
[0008] Therefore, it is very important to develop a long-term effective ion exchange membrane surface processing method; during the zero polar distance electrolysis process, the ion exchange membrane is able to continuously provide excellent anti-foaming effect, reduce the cell voltage, improve the current efficiency and reduce the power consumption.
SUMMARY OF THE PRESENT INVENTION
[0009] In view of deficiencies in the prior art, an object of the present invention is to provide a zero polar distance ion exchange membrane, which is adapted for chlor-alkali industry, so as to stably and highly-effective process the alkali metal chloride solution with higher impurity content, is more suitable for operating in a zero polar distance electrolytic cell under a condition of high current density, and has a very low surface resistance. Furthermore, the present invention also provides a preparation method of the zero polar distance ion exchange membrane, which facilitates the industrial production.
[0010] The zero polar distance ion exchange membrane, provided by the present invention, is a polymer membrane compositely prepared by perfluorinated ion exchange resin and a reinforcement material, wherein: the polymer membrane is converted to the ion exchange membrane, a non-electrode multi-porous gas release layer is attached to at least one side of the ion exchange membrane; the non-electrode multi-porous gas release layer is formed by drying after adhering a dispersion liquid to the ion exchange membrane surface; the dispersion liquid is formed by dispersing perfluorosulfonic acid resin broken micro-particles in a sulfonic acid resin water alcohol solution.
[0011] In which:
[0012] The perfluorosulfonic acid resin broken micro-particles are formed by converting perfluorosulfonic acid resin in NaOH solution to sodium-type, and then grinding through a nano grinding machine, and finally obtaining the broken micro-particles with irregular polyhedron morphology, wherein: the nano grinding machine is a nano grinding machine with deep cooling; during the grinding process, a strong shearing force applied to the resin particles allows the broken micro-particles to have the irregular polyhedron morphology; the micro-particles with the irregular polyhedron morphology are not easy to be reunited and has uniform particle size and good dispersion effect. The perfluorosulfonic acid resin broken micro-particles has the ion exchange function.
[0013] The reinforcement material is one of a mesh material, a fibrous material, a nonwoven fabric material and a porous membrane material which are made of any one of polytetrafluoroethylene (PTFE), polyperfluoroalkoxy resin (PFA), poly ethylene propylene (FEP), and ethylene-tetrafluoroethylene copolymer (ETFE). It is adapted for improving the mechanical strength and prepared by the prior art.
[0014] A surface hydrophilic contact angle of the ion exchange membrane attached with the non-electrode multi-porous gas release layer is smaller than 90°, and a surface resistance of the ion exchange membrane is lower than 1.2 Ω·cm −2 .
[0015] An ion exchange capability of the perfluorosulfonic acid resin broken micro-particles is in a range of 0.4-0.9 mmol/g; and preferably, 0.5-0.7 mmol/g. When the ion exchange capability is too high, the perfluorosulfonic acid resin broken micro-particles in the water alcohol solution have a certain swelling degree, so that the own irregular morphology of the broken particles are destroyed; and a volume of the broken particles is expanded, such that a porosity is seriously reduced and ion channels are blocked; the broken particles are not easily broken.
[0016] A particle size of the perfluorosulfonic acid resin broken micro-particles is in a range of 0.05-20 μm; and preferably, 0.1-8 μm. When the particle size is too low, the particles are easily reunited to block the ion channels; when the particle size is too high, the micro-particles formed on the membrane surface obviously protrudes from the membrane surface, so that they are easy to be detached from the membrane surface under external scratches.
[0017] The perfluorosulfonic acid resin broken micro-particles are dispersed in the sulfonic acid resin water alcohol solution to form the dispersion liquid, so as to obviously improve the surface hydrophilicity and the desorption function to produced gases of the ion exchange membrane.
[0018] In the dispersion liquid, a content of the perfluorosulfonic acid resin broken micro-particles by weight is 5-40%, and preferably, 8-20%.
[0019] In the sulfonic acid resin water alcohol solution, a content of the sulfonic acid resin by weight is 0.05-20%, and preferably, 0.5-10%. The study found that if the content of the sulfonic acid resin is too high, then the dispersion liquid has high viscosity, which goes against manufacturing the multi-porous coating. Furthermore, the sulfonic acid resin water alcohol solution with too high viscosity will affect the dispersion effect of the perfluorosulfonic acid resin broken micro-particles therein, so that the gas release effect is reduced. In addition, too high viscosity will result in a decrease of the porosity of the gas release layer, thereby affecting an operation effect of the membrane under the high current density.
[0020] The dispersion liquid is sprayed onto the ion exchange membrane surface, and then is dried, a distribution quantity of the perfluorosulfonic acid resin broken micro-particles on the polymer membrane surface is 0.01-15 mg/cm 2 , and preferably, 0.05-8 mg/cm 2 . The present invention found that if the distribution quantity of the particles is too small, the gas release effect is reduced.
[0021] The surface hydrophilic contact angle of the ion exchange membrane attached with the non-electrode multi-porous gas release layer is smaller than 90°, the smaller the contact angle, the better the hydrophilicity and the easier desorption of the surface gas. The surface resistance of the ion exchange membrane is lower than 1.2 Ω·cm −2 .
[0022] A proportion of water and alcohol in the sulfonic acid resin water alcohol solution is selected according to the prior art, the alcohol is preferably methanol, ethanol, propanol, ethylene glycol or isopropanol. Preferably, the proportion of the water and the alcohol is 1:1.
[0023] The non-electrode multi-porous gas release layer on the ion exchange membrane surface is formed by multiple kinds of processes. A conventional surface coating preparation method comprises spray coating, brush coating, roll coating, dipping, transferring and spin coating; and preferably, is spray coating and roll coating. The process is processed according to the prior art.
[0024] The non-electrode multi-porous gas release layer has a width within a range of 0.1-30 nm, is able to be only attached to a single side of the ion exchange membrane, and be synchronously attached to two sides of the ion exchange membrane. The ion exchange membrane, provided by the present invention is used to be a separation membrane in an alkaline electrolysis cell, wherein: one side of the ion exchange membrane attached with the non-electrode multi-porous gas release layer is preferably installed at a cathode side of the electrolysis cell, for stably and highly-effectively processing the alkali metal chloride solution with high impurity content.
[0025] The non-electrode multi-porous gas release layer is a non-continuous multi-porous layer, has a porosity of 35-99%, and preferably, 60-95%; the non-electrode multi-porous gas release layer is a discontinuous multi-porous structure formed by the sulfonic acid resin in the water alcohol solution encasing the perfluorosulfonic acid resin broken micro-particles in a discontinuous state. The non-electrode multi-porous gas release layer is too low in porosity, which results in an increase of the cell pressure.
[0026] The polymer membrane is compositely prepared by a perfluorinated ion exchange resin and a reinforcing material. The perfluorinated ion exchange resin is a single-layer membrane or a composite membrane, which is prepared by one or multiple kinds of perfluorinated ion exchange resin containing one or two functional groups in sulfonic acid or carboxylic acid, through a single or multi-machine co-extrusion method. It is able to be sulfonic acid single layer membrane, sulfonic acid carboxylic acid mixing single layer membrane, sulfonic acid/sulfonic acid composite membrane, sulfonic acid/carboxylic acid composite membrane, sulfonic acid/sulfonic acid carboxylic acid copolymer/carboxylic composite membrane, sulfonic acid/sulfonic acid carboxylic acid mixture/carboxylic composite membrane. Preparation methods of all polymer membranes are based on the prior art.
[0027] A preparation method of the zero polar distance ion exchange membrane, provided by the present invention, comprises steps of:
[0028] (1) through a screw extruder, in a co-extrusion manner, melting and casting perfluorinated ion exchange resin to a single layer membrane or a multi-layer composite membrane, and simultaneously, introducing a reinforcement material between two membrane forming rollers, pressing the reinforcement material into a membrane body under an action of a pressure between the rollers, and forming a polymer membrane;
[0029] (2) immersing the polymer membrane in the step (1) to a mixed aqueous solution of dimethyl sulfoxide and NaOH, and converting the polymer membrane into an ion exchange membrane with ion exchange function;
[0030] (3) dissolving perfluorosulfonic acid resin, putting the dissolved perfluorosulfonic acid resin into a water alcohol mixture, forming sulfonic acid resin water alcohol solution, adding perfluorosulfonic acid resin broken micro-particles, homogenizing in a ball mill, and forming a dispersion liquid; and
[0031] (4) through surface coating, adhering the dispersion liquid to the ion exchange membrane surface obtained in the step (2), forming a discontinuous multi-porous gas release layer after drying, and obtaining a product.
[0032] Wherein, in the step (1), the perfluorinated ion exchange resin is one or more, one or more screw extruders are adopted, and an extrusion manner is a single layer or multi-layer co-extrusion manner.
[0033] In the step (2), preferably, a content of dimethyl sulfoxide in the mixed aqueous solution by weight is 15 wt % and a content of NaOH in the mixed aqueous solution by weight is 20 wt %.
[0034] The non-electrode multi-porous gas release layer on the ion exchange membrane surface is formed by multiple kinds of processes. The surface coating preparation method in the step (4) comprises spray coating, brush coating, roll coating, dipping, transferring and spin coating; and preferably, is spray coating and roll coating. The process is processed according to the prior art.
[0035] The zero polar distance ion exchange membrane, prepared by the above method, for chlor-alkali industry is able to stably and highly-effectively process the alkali metal chloride solution with high impurity content, is better adopted for operating in a zero polar distance electrolysis cell under the condition of high current density, and has a very low surface resistance.
[0036] In conclusion, the present invention has advantages as follows.
[0037] (1) The perfluorosulfonic acid resin broken micro-particles have the ion exchange function, are attached to the ion exchange membrane surface and no block is formed, so that the present invention is very adapted for being operated under high current density.
[0038] (2) The surface hydrophilic contact angle of the ion exchange membrane attached with the non-electrode multi-porous gas release layer is smaller than 90°. The excellent hydrophilicity of the present invention effectively reduces the accumulation of the bubbles on the membrane surface, thereby significantly reducing the surface resistance and the cell voltage.
[0039] (3) The perfluorosulfonic acid resin broken micro-particles has excellent compatibility with the ion exchange membrane, and are not easy to be detached from each other. During the whole service life time of the membrane, the function which suppresses the generation of bubbles is not attenuated with the extension of time.
[0040] (4) The zero polar distance ion exchange membrane prepared by the present invention in the zero polar distance electrolytic cell is able to achieve the following technical indicators: under the condition that the current density is 6 kA/m 2 or even higher, the surface resistance ≦1.2 Ω·cm −2 , the average cell voltage ≦2.85 V, the average current efficiency ≧98.5%, and the tested wear loss of the ion exchange membrane ≦5 mg using the ASTM Standard D 1044-99.
[0041] (5) In the zero polar distance electrolysis process, the zero polar distance ion exchange membrane prepared by the present invention is able to continuously provide good anti-foaming effect, reduce the cell voltage, improve the current efficiency and reduce the power consumption.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0042] The present invention is further explained with accompanying embodiments in detail.
[0043] Concentrations in the examples are by mass unless otherwise specified.
[0044] A polymer membrane described in the examples is made of perfluorinated ion exchange resin with a structure as follows, wherein: a repetitive unit of sulfonic acid resin is
[0000]
[0045] a repetitive unit of carboxylic acid resin is
[0000]
[0046] a repetitive unit of sulfonic acid carboxylic acid polymer is
[0000]
Example 1
[0047] A preparation method of a zero polar distance ion exchange membrane comprises steps of:
[0048] (1) processing perfluorosulfonic acid resin with IEC=1.4 mmol/g, perfluorosulfonic acid carboxylic acid copolymer resin with IEC=1.0 mmol/g and perfluorocarboxylic acid resin with IEC=0.95 mmol/g, with a mass fraction ratio of 100:5:10 in a co-extrusion and cast manner, forming a composite membrane with a total thickness of 135 μm; and simultaneously, introducing a PTFE (polytetrafluoroethylene) mesh fabric between two membrane forming rollers, the PTFE mesh fabric entering a membrane body through rolling compounding, and forming a polymer membrane;
[0049] (2) immersing the polymer membrane in the step (1) to a mixed aqueous solution of dimethyl sulfoxide with a weight percentage of 15 wt % and NaOH with a weight percentage of 20 wt % for 80 minutes at 85° C., and then converting the polymer membrane into an ion exchange membrane with ion exchange function;
[0050] (3) preparing a water alcohol mixture by mixing water and alcohol with a weight ratio of 1:1, dissolving perfluorosulfonic acid resin with IEC=0.9 mmol/g, putting the dissolved perfluorosulfonic acid resin into the water alcohol mixture, forming sulfonic acid resin solution with a concentration of 2 wt %, adding perfluorosulfonic acid resin broken micro-particles with IEC=0.78 mmol/g, an average particle size of 0.5 pm and irregular polyhedron morphology to the sulfonic acid resin solution, homogenizing in a ball mill, and forming a dispersion liquid with a content of 15 wt %; and
[0051] (4) through spraying, adhering the dispersion liquid to surfaces at two sides of the ion exchange membrane surface obtained in the step (2), and forming a discontinuous multi-porous gas release layer with a porosity of 86% after drying, wherein: a distribution quantity of the perfluorosulfonic acid resin broken micro-particles on the composite membrane surface is 4.6 mg/cm 2 , a hydrophilicity of the membrane is tested by a contact angle measuring instrument, and a contact angle is 77°.
Performance Testing
[0052] An electrolytic test of the prepared ion exchange membrane about NaCl aqueous solution in an electrolysis cell is performed. 300 g/L NaCl aqueous solution is supplied to an anode chamber, water is supplied to a cathode chamber, it is ensured that a concentration of NaCl discharged from the anode chamber is 200 g/L, and a concentration of NaOH discharged from the cathode chamber is 32%; a test temperature is 90° C., a current density is 8 kA/m 2 ; after 23 days of electrolysis experiments, the average cell voltage is 2.73 V and the average current efficiency is 99.1%.
[0053] Afterwards, based on standard SJ/T 10171.5, a surface resistance of the obtained membrane is tested to be 1.0 Ω·cm −2 ; based on ASTM Standard D 1044-99, a wear loss of the obtained membrane is tested to be 2.6 mg.
Comparative Example 1
[0054] A same method as the example 1 is adopted to prepare the ion exchange membrane with ion exchange function; afterwards, a same method is adopted to prepare the dispersion liquid. Differences between the example 1 and the comparative example 1 are as follows. The perfluorosulfonic acid resin broken micro-particles in the dispersion liquid are replaced by zirconium oxide particles with an average particle size of 0.5 μm, and then homogenized in the ball mill, and the dispersion liquid with a content of 15 wt % is formed. The same method is adopted to obtain the ion exchange membrane attached with the discontinuous multi-porous gas release layer at two sides thereof. The distribution quantity of the zirconium oxide particles on the composite membrane surface is also 4.6 mg/cm 2 , the porosity of the membrane is reduced to 73%; the hydrophilicity thereof is tested by the contact angle measuring instrument, and the contact angle is 126°.
[0055] Under the same conditions as the example 1, the electrolytic test of NaCl aqueous solution is performed. After 23 days of electrolysis experiments, the average cell voltage is 2.98 V, the average current efficiency is 96.0%, the surface resistance is 2.3 Ω·cm −2 , and the wear loss is 7.4 mg.
Example 2
[0056] A same method as the example 1 is adopted to prepare an ion exchange membrane with ion exchange function. Afterwards, a water alcohol mixture is prepared by mixing water and alcohol with a weight ratio of 1:1, perfluorosulfonic acid resin with IEC=0.9 mmol/g is dissolved, the dissolved perfluorosulfonic acid resin is put into the water alcohol mixture, sulfonic acid resin solution with a concentration of 6 wt % is formed; and then perfluorosulfonic acid resin broken micro-particles with IEC=0.45 mmol/g, an average particle size of 0.05 μm and irregular polyhedron morphology are added to the sulfonic acid resin solution and are homogenized in a ball mill, and a dispersion liquid with a content of 9 wt % is formed.
[0057] Through spraying, the dispersion liquid is adhered to surfaces at two sides of the above ion exchange membrane surface, and a discontinuous multi-porous gas release layer with a porosity of 91% is formed after drying, wherein: a distribution quantity of the perfluorosulfonic acid resin broken micro-particles on the composite membrane surface is 5.2 mg/cm 2 , a hydrophilicity of the membrane is tested by a contact angle measuring instrument, and a contact angle is 81°.
[0058] An electrolytic test of the prepared ion exchange membrane about NaCl aqueous solution in an electrolysis cell described in Example 1 is performed; a current density is 10 KA/m 2 ; after 17 days of electrolysis experiments, an average cell voltage is 2.79 V, and an average current efficiency is 99.0%.
[0059] Afterwards, based on standard SJ/T 10171.5, a surface resistance of the obtained membrane is tested to be 0.90 Ω·cm −2 ; based on ASTM Standard D 1044-99, a wear loss of the obtained membrane is tested to be 3.1 mg.
Example 3
[0060] A same method as the example 1 is adopted to prepare an ion exchange membrane with ion exchange function. Afterwards, a water alcohol mixture is prepared by mixing water and propanol with a weight ratio of 1:1, perfluorosulfonic acid resin with IEC=0.9 mmol/g is dissolved, the dissolved perfluorosulfonic acid resin is put into the water alcohol mixture, sulfonic acid resin solution with a concentration of 1 wt % is formed; and then perfluorosulfonic acid resin broken micro-particles with IEC=0.75 mmol/g, an average particle size of 5 μm and irregular polyhedron morphology are added to the sulfonic acid resin solution and are homogenized in a ball mill, and a dispersion liquid with a content of 4.6 wt % is formed.
[0061] Through spraying, the dispersion liquid is adhered to surfaces at two sides of the above ion exchange membrane surface, and a discontinuous multi-porous gas release layer with a porosity of 94% is formed after drying, wherein: a distribution quantity of the perfluorosulfonic acid resin broken micro-particles on the composite membrane surface is 6.8 mg/cm 2 , a hydrophilicity of the membrane is tested by a contact angle measuring instrument, and a contact angle is 68°.
[0062] An electrolytic test of the prepared ion exchange membrane about NaCl aqueous solution in an electrolysis cell described in Example 1 is performed; a current density is 12 KA/m 2 ; after 23 days of electrolysis experiments, an average cell voltage is 2.83 V, and an average current efficiency is 99.0%.
[0063] Afterwards, based on standard SJ/T 10171.5, a surface resistance of the obtained membrane is tested to be 0.95 Ω·cm −2 ; based on ASTM Standard D 1044-99, a wear loss of the obtained membrane is tested to be 2.1 mg.
[0064] Afterwards, 10 ppm organic matter n-chlorododecyl trimethyl ammonium chloride is added to the NaCl aqueous solution. Under the same conditions as the above description, after 40 days of electrolysis experiments, an average cell voltage is 2.85 V, and an average current efficiency is 99.0%.
Example 4
[0065] Differences between the example 4 and the example 3 are as follows. In the example 4, the prepared dispersion liquid is coated to one side of the ion exchange membrane with ion exchange function mentioned in the example 3 in a brush coating manner, and the side is installed to a cathode side of an electrolytic cell; after drying, a discontinuous multi-porous gas release layer with a porosity of 94% is formed; a distribution quantity of the perfluorosulfonic acid resin broken micro-particles on the composite membrane surface is 3.4 mg/cm 2 , a hydrophilicity of the membrane is tested by a contact angle measuring instrument, and a contact angle is 68°.
[0066] An electrolytic test of the prepared ion exchange membrane about NaCl aqueous solution in an electrolysis cell described in Example 1 is performed; a current density is 12 KA/m 2 ; after 23 days of electrolysis experiments, an average cell voltage is 2.85 V, and an average current efficiency is 98.6%.
[0067] Afterwards, based on standard SJ/T 10171.5, a surface resistance of the obtained membrane is tested to be 1.2 Ω·cm −2 ; based on ASTM Standard D 1044-99, a wear loss of the obtained membrane is tested to be 2.1 mg.
Example 5
[0068] Differences between the example 5 and the example 3 are as follows. In the example 5, the prepared dispersion liquid is coated to one side of the ion exchange membrane with ion exchange function mentioned in the example 3 in a brush coating manner, and the side is installed to an anode side of an electrolytic cell; after drying, a discontinuous multi-porous gas release layer with a porosity of 94% is formed; a distribution quantity of the perfluorosulfonic acid resin broken micro-particles on the composite membrane surface is 3.4 mg/cm 2 , a hydrophilicity of the membrane is tested by a contact angle measuring instrument, and a contact angle is 68°.
[0069] An electrolytic test of the prepared ion exchange membrane about NaCl aqueous solution in an electrolysis cell described in Example 1 is performed; a current density is 12 KA/m 2 ; after 23 days of electrolysis experiments, an average cell voltage is 3.07 V, and an average current efficiency is 96.6%.
[0070] Afterwards, based on standard SJ/T 10171.5, a surface resistance of the obtained membrane is tested to be 2.7 Ω·cm −2 ; based on ASTM Standard D 1044-99, a wear loss of the obtained membrane is tested to be 2.1 mg.
Example 6
[0071] (1) processing perfluorosulfonic acid resin with IEC=1.2 mmol/g, and a blending resin forming by mixing perfluorosulfonic acid with IEC=1.3 mmol/g and perfluorocarboxylic acid with IEC=0.89mmol/g in a proportion of 1:1, with a mass fraction ratio of 100:9 in a co-extrusion and cast manner, forming a composite membrane with a total thickness of 120 μm; and simultaneously, introducing a PFA non-woven fabric between two membrane forming rollers, the PFA non-woven fabric entering a membrane body through rolling compounding, and forming a polymer membrane;
[0072] (2) immersing the polymer membrane in the step (1) to a mixed aqueous solution of dimethyl sulfoxide with a weight percentage of 15 wt % and NaOH with a weight percentage of 20 wt % for 80 minutes at 85° C., and then converting the polymer membrane into an ion exchange membrane with ion exchange function;
[0073] (3) preparing a water alcohol mixture by mixing water and isopropanol with a weight ratio of 2:1, dissolving perfluorosulfonic acid resin with IEC=0.95 mmol/g, putting the dissolved perfluorosulfonic acid resin into the water alcohol mixture, forming sulfonic acid resin solution with a concentration of 0.05 wt %, adding perfluorosulfonic acid resin broken micro-particles with IEC=0.9 mmol/g, an average particle size of 10 um and irregular polyhedron morphology to the sulfonic acid resin solution, homogenizing in a ball mill, and forming a dispersion liquid with a content of 40 wt %; and
[0074] (4) through brush coating, adhering the dispersion liquid to surfaces at two sides of the ion exchange membrane surface obtained in the step (2), and forming a discontinuous multi-porous gas release layer with a porosity of 99% after drying, wherein: a distribution quantity of the perfluorosulfonic acid resin broken micro-particles on the composite membrane surface is 0.6 mg/cm 2 , a hydrophilicity of the membrane is tested by a contact angle measuring instrument, and a contact angle is 74°.
[0075] An electrolytic test of the prepared ion exchange membrane about NaCl aqueous solution in an electrolysis cell described in Example 1 is performed; a current density is 8 KA/m 2 ; after 43 days of electrolysis experiments, an average cell voltage is 2.71 V, and an average current efficiency is 99.2%.
[0076] Afterwards, based on standard SJ/T 10171.5, a surface resistance of the obtained membrane is tested to be 1.0 Ω·cm −2 ; based on ASTM Standard D 1044-99, a wear loss of the obtained membrane is tested to be 2.9 mg.
Example 7
[0077] The substrate membrane prepared in the embodiment 6 is enhanced by adopting FEP multi-porous membrane to form a polymer membrane; and then is converted into an ion exchange membrane under same conversion conditions.
[0078] Afterwards, a water alcohol mixture is prepared by mixing water and ethanol with a weight ratio of 1:1.2, perfluorosulfonic acid resin with IEC=1.05 mmol/g is dissolved, the dissolved perfluorosulfonic acid resin is put into the water alcohol mixture, sulfonic acid resin solution with a concentration of 20 wt % is formed; and then perfluorosulfonic acid resin broken micro-particles with IEC =0.4 mmol/g, an average particle size of 20 pm and irregular polyhedron morphology are added to the sulfonic acid resin solution and are homogenized in a ball mill, and a dispersion liquid with a content of 5 wt % is formed.
[0079] Through spraying, the dispersion liquid is adhered to surfaces at two sides of the above ion exchange membrane surface, and a discontinuous multi-porous gas release layer with a porosity of 35% is formed after drying, wherein: a distribution quantity of the perfluorosulfonic acid resin broken micro-particles on the composite membrane surface is 15 mg/cm 2 , a hydrophilicity of the membrane is tested by a contact angle measuring instrument, and a contact angle is 83°.
[0080] An electrolytic test of the prepared ion exchange membrane about NaCl aqueous solution in an electrolysis cell described in Example 1 is performed; a current density is 10 KA/m 2 ; after 13 days of electrolysis experiments, an average cell voltage is 2.83 V, and an average current efficiency is 99.0%.
[0081] Afterwards, based on standard SJ/T 10171.5, a surface resistance of the obtained membrane is tested to be 1.2 Ω·cm −2 ; based on ASTM Standard D 1044-99, a wear loss of the obtained membrane is tested to be 3.8 mg. | A zero polar distance ion exchange membrane. A polymer membrane is compositely prepared by a perfluorinated ion exchange resin and a reinforcing material, and the polymer membrane is converted into an ion exchange membrane. A non-electrode porous gas release layer is adhered to at least one side of the ion exchange membrane. The non-electrode porous gas release layer is formed by drying after adhering a dispersion liquid to an ion exchange membrane layer surface. The dispersion liquid is formed by dispersing perfluorinated sulphonic acid resin broken micro-particles in a sulphonic acid resin aqueous alcohol solution. The prepared zero polar distance ion exchange membrane is used in the chlor-alkali industry, stably and effectively treats an alkali metal chloride solution having a high impurity content, is able to better suited for operating in a zero polar distance electrolysis cell under high current density conditions, and has a very low surface resistance. Also provided is a preparation method for the zero polar distance ion exchange membrane. The preparation method has a simple and reasonable process, and facilitates industrial production. | 7 |
CROSS-REFERENCE TO RELATED APPLICATION
[0001] The present document is based on and claims priority to U.S. Provisional Application Ser. No. 61/334,170, filed May 12, 2010.
TECHNICAL FIELD
[0002] The present application relates to downhole oilwell equipment, and more particularly, to corrosion and cracking material determination.
BACKGROUND
[0003] Fluids and gasses are contained in the earth. Many of these fluids and gasses are desirable and valuable for consumption purposes, e.g., gas, oil and water. To extract these fluids, a well is drilled into the earth. The wells can be very deep and often up to a mile or more in depth. These wells can be vertical or horizontal or a combination thereof.
[0004] Once a well is drilled, at least a portion of the well is generally lined with a metal casing. This metal casing can have cement filled between the outside of the casing and the earth formation to fill empty spaces.
[0005] After the casing is implemented, completions are located in the well to relay tools, packers, and to produce fluids. The completions often include piping or tubing, valves, and/or other well known instruments.
[0006] There are production areas along the wellbore, e.g., where oil is present, and others where oil is not present or present to a lesser degree. Given that, it is often desirable to only extract fluids from one section of the well. When that is the case, packers are used to isolate a portion of the wellbore from other portions for fluid extraction purposes. Often, the portion of the wellbore that is to be produced is perforated with a perforating gun while that portion remains separate.
[0007] Downhole environments can be very harsh. The fluids that are extracted are often quite harsh themselves, and additional fluids are often present. These additional fluids can be acidic and otherwise degrade various materials used to make completions and other equipment. In addition, high temperatures and pressures can be present. Frictional degradation and physical wear (e.g., from abrasives present in a well) can also be faced. In sum, tools placed downhole in wells face a number of factors that can all contribute to degradation of a tool material.
[0008] Accordingly, it is desirable to gain knowledge of potential degradation of various materials when exposed to actual wellbore environments.
SUMMARY
[0009] An embodiment according to the present application includes a tool string sub. A longitudinally extending tubular housing has an outside surface and an inside surface. A stepped circumferential portion of the inside surface of the housing bisects the interior surface of the housing. A degradation part is connected adjacent to the stepped portion of the housing and is supported by the housing and at least one moveable support part protruding inward and beyond the inner surface of the housing. The support part has a first position where the degradation part is at one stress and a second position where the degradation part is at a second stress greater than the first stress. The present application relates to embodiments that can be capable of varying the stresses on the degradation part from zero to beyond its yield strength. Also the stresses can be induced not only using screws, sliding keys or wedges, but by the geometry of the housing itself. At least one end of the tool string sub is adapted to connect with a tool string.
BRIEF SUMMARY OF THE FIGURES
[0010] The brief description of the figures is not meant to unduly limit any claims in this or any related application.
[0011] FIG. 1 shows a side schematic view of a tool string including an embodiment of the tool string sub.
[0012] FIG. 2 shows a side section view of an embodiment of the tool string sub.
[0013] FIG. 3 shows a top section view of an embodiment of the tool string sub.
[0014] FIG. 4 shows a top section view of an embodiment of the tool string sub.
[0015] FIG. 5 shows a top section view of an embodiment of a tool string sub.
[0016] FIG. 6 shows a top section view of an embodiment of a tool string sub.
[0017] FIG. 7 shows a side section partial view of an embodiment of a tool string sub with an inner tubular member.
DETAILED DESCRIPTION
[0018] The following description concerns a number of embodiments and is meant to provide an understanding of the embodiments. The description is not in any way meant to limit the scope of any present or subsequent related claims.
[0019] As used here, the terms “above” and “below”; “up” and “down”; “upper” and “lower”; “upwardly” and “downwardly”; and other like terms indicating relative positions above or below a given point or element are used in this description to more clearly describe some embodiments. However, when applied to equipment and methods for use in wells that are deviated or horizontal, such terms may refer to a left to right, right to left, or diagonal relationship as appropriate.
[0020] Corrosion and environmental cracking of downhole alloys in fit for service tests are generally conducted in simulated bottomhole fluids at P-T conditions. Equilibrium of co-existing phases is normally a question in the time scale of a test (30 to 90 days) in contrast to geological time (millions of years). Also, exposure can be in fluids that are static (extremely difficult to simulate high flow rates and associated dynamic flow effects (eddies' etc.)). It is apparent that simulated bottomhole tests along these lines have various drawback that would make actual bottomhole testing preferable.
[0021] Various embodiments in the present application relate to apparatus and methods for monitoring corrosion and cracking of alloys during live well testing. These can improve understanding of survivability of materials, particularly that of lower alloys and coatings, when exposed to downhole wellbore environments. According to embodiments, a sub containing corrosion and stressed C-rings (degradation parts) could be integrated and deployed with a testing tool string or be an integrated part of any other tool string. The tool string could be deployed on drill pipe, production tubing, coil tubing, or wireline. The C-ring or corrosion coupons or any other stressed degradation parts could then be removed with the tool string, drill pipe or tubing, and evaluated. The information gathered would have value to those involved in the selection of materials for use in a particular well completion string or other tooling. This could also apply to selection of coatings for tooling and completions in wells.
[0022] According to embodiments, a number of factors for the C-ring or corrosion coupons or any other stressed or unstressed degradation parts (degradation part) can be evaluated such as corrosion and cracking of the part itself and of any coatings applied there to during exposure to downhole environments. The degradation part can be made from any material which is to be investigated.
[0023] Looking more specifically at the drawings, FIG. 1 shows a side schematic view of a portion of a tool string. The tool string has tubing 13 that in practice extends downhole into a well bore from surface. In place of the tubing, a wireline or slickline could be used. The tubing could be drill pipe, production tubing, or coil tubing. The tubing can be connected with a testing tool 12 (e.g., a closed chamber testing tool). The testing tool 12 can also be replaced with a perforating gun or an artificial lift device such as an electric submersible pump. Fracturing equipment can also be used. Also, SAGD equipment such as steam and heat producing devices, as well as drainage device, can be used. Below the testing tool 12 is connected a tool string sub 1 according to embodiments of the present application. It should be noted that the tool string sub 1 can be in the location shown in FIG. 1 , but could also be located in other parts of a tool string (can be deployed at any depth of the well-position dependent design). For example, the tool string sub 1 could be above the testing tool 12 . Also, more than one tool string sub 1 can be incorporated in a tool string at different locations. In cases where packers are used to isolate a zone of the well, the tool string sub 1 can be located below a safety valve that is in the tool string or tubing. However, in other configurations the tool string sub 1 can be located above a safety valve. However above the packer, where a tubing and annulus needs to be isolated, the sub needs sealing between these and fluid contact from the 10.
[0024] FIG. 2 is a side view section of a tool string sub 1 according to embodiments in the present application. The tool string sub 1 can be a longitudinally extending tubular part having a centerline as shown. The tool string sub 1 can be made from metal such as iron or steel, alloys and variations thereof. The tool string sub 1 has a housing 7 with an outside surface and an inside surface. In the embodiment shown in FIG. 1 , the inside surface has a stepped portion 11 that extends around the internal circumference of the inner surface of the tool string sub 1 and bisects the inner surface of the tool string sub 1 . The stepped portion 11 can divide an area of the tool string sub 1 having a smaller inside diameter from a side of the tool string sub 1 having a larger inside diameter. However, the stepped portion 11 could also be part of a protrusion or lip extending around the inner surface of the tool string sub 1 . The inner sleeve will prevent corroded/cracked pieces from falling into the well bore.
[0025] A degradation part 2 (C-Ring in FIG. 2 ) is shown as being located adjacent to and supported by the stepped portion 11 . The degradation parts can be stacked enabling study of crevice, pitting corrosion and environmental cracking of galvanically coupled alloys. A plurality of support parts 4 in the form of screws extend through the housing 7 of the tool string sub 1 and contact/support the C-ring. When in a first position (unscrewed) the support parts (screws) 3 maintain the C-ring at a first stress. When in a second position (screwed) the support parts (screws) 3 maintain the C-ring (degradation part) 2 at a second stress that is greater than the first stress. The stresses expressed on the degradation part could be 0 to 100% of temperature rated yield strength of the material being tested. The thickness of the tool string sub could be 0.5 to 4 inches. The length of the tool string sub could be from 2 to 6 feet long. These dimensions correspond to the normal requirements of well tools of this sort. Also, the tool string sub could be an integral part of any tool string. These dimensions in connection with the resultant strength attributes lend to an ability to perform properly in downhole activities. Additionally, the support parts can be non-moveable where the degradation part is forced into a stressed position.
[0026] Perforations 6 are shown extending through the housing 7 of the tool string sub 1 from the outside of the tool string sub 1 to the inside surface of the tool string sub proximate the degradation part 2 . The perforations can be designed to allow flow of well fluids from outside the tool string sub 1 to the inside of the tool string sub 1 to contact the degradation part 2 or from inside and also prevent outside to inside flow if needed. The perforations can have a diameter of approximately 0.25 to 1 inch or slots.
[0027] FIG. 3 shows a top sectional view of a tool string sub 1 according to embodiments. The tool string sub 1 has a housing 7 with a stepped portion 11 . A degradation part 2 (C-ring) (or corrosion coupons or any other stressed degradation parts) is located adjacent to and supported by the stepped portion 11 . Two support parts 4 interact with the C-ring 2 (or corrosion coupons or any other stressed degradation parts). When in a second position the support parts 4 create a stress on the C-ring 2 . O-rings 5 can be incorporated with the support parts 4 for protection. Perforations 6 extend through the housing 7 and are proximate to the degradation part 2 .
[0028] FIG. 4 shows a top sectional view of the tool string sub 1 according to embodiments. In FIG. 4 , the degradation part 2 is almost a full 360 degree ring and only has one opening therein. The degradation part 2 is again supported proximate the stepped portion 11 . In FIG. 4 a wedge 8 interacts with the opening in the degradation part 2 and exerts force on the degradation part 2 so as to create a stress in the degradation part 2 . Perforations 6 extend through the housing 7 . The stress directions on the degradation parts can be reversed. Stresses can be either compressive or tensile on either the inner or outer fiber of the degradation part as required.
[0029] FIG. 5 shows a top sectional view of a tool string sub 1 according to embodiments of the present application. In this design, each half of the tool string sub 1 is a mirror image of the other. The tool string sub 1 has two C-rings 2 , each with two support parts (screws) 4 . The degradation parts (C-rings) 2 are supported by the stepped portion 11 and are contacted by the support parts (screws) 3 . Perforations 6 extend through the housing 7 proximate the C-rings 2 .
[0030] FIG. 6 shows a similar design as in FIG. 5 , except includes support parts 4 that are keys. The keys are located in key slots 9 . When the keys are in the key slots 9 , the C-ring has stress applied thereto. Perforations 6 extend through the housing 7 .
[0031] FIG. 7 shows a side sectional view of a portion of a tool string sub 1 according to embodiments in the present application. The housing 7 of the tool string sub 1 has a stepped portion 11 . The stepped portion 11 is adjacent to and supports an inner tubular part 14 . A degradation part 2 is contained in a space defined by the inner surface of the housing 7 , the stepped portion 11 and the inner tubular part 14 . The degradation part 2 is up hole from the stepped portion 11 so as to prevent the degradation part 2 from falling downhole.
[0032] The tool string sub will also allow a study of stressed degradation parts to be exposed to annulus fluids above the packer to study effects of corrosion and environmental cracking in completions brines, such as Cesium Formate and Acetate, etc. The flexibility to run this tool string sub (design based) anywhere along the tubing, above or below the packer will be relevant in acquiring corrosion data at various temperatures, pressures and locations (below or above dew point of produced vapors), to help design upper-middle or lower completions.
[0033] The preceding description is meant to help one skilled in the art understand the embodiments described herein and is not in any way mean to unduly limit the scope of any present or subsequent claims. | A tool string sub. A longitudinally extending tubular housing has an outside surface and an inside surface. A stepped circumferential portion of the inside surface of the housing bisects the interior surface of the housing. A degradation part is connected adjacent to the stepped portion of the housing and is supported by the housing and at least one moveable support part protruding inward and beyond the inner surface of the housing. The support part has a first position where the degradation part is at one stress and a second position where the degradation part is at a second stress greater than the first stress. At least one end of the tool string sub is adapted to connect with a tool string. | 8 |
This application is a continuation application of Ser. No. 09/587,792, filed on Jun. 6, 2000, now U.S. Pat. No. 6,741,834, for DEVICE AND METHOD TO IMPROVE INTEGRATED PRESENTATION OF EXISTING RADIO SERVICES AND ADVANCED MULTIMEDIA SERVICES by John P. Godwin.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to systems and methods for providing program material to subscribers, and in particular to a method and system for integrating a national media program broadcast with existing regional radio broadcasts.
2. Description of the Related Art
Media programming, such as audio programs, are distributed to viewers by a variety of broadcasting methods. These methods include traditional amplitude modulated (AM) and frequency modulated (FM) analog broadcast radio, and audio channels carried by direct broadcast television providers such as DIRECTV Inc. In the near future, digital broadcast radio such as the Satellite Digital Audio Radio Service (SDARS) envisioned by XM RADIO, Inc., will also be available. When it becomes available, SDARS will provide subscribers with new, previously unavailable high quality media services, even in mobile environments like the automobile. The SDARS system uses one or more satellites to broadcast audio and advanced multimedia programs. The satellite broadcasts can be received directly by subscriber receivers at home, at business locations, or in mobile vehicles. The satellite broadcasts will also be received and retransmitted by terrestrial repeaters to provide improved coverage and availability. This technique is especially useful for mobile receivers operated in urban areas with multi-story structures, which may cause shadowing.
SDARS provides superior transmission quality and diversity of choice of programming. However, many potential customers have become accustomed to listening to media programs transmitted by their local AM and FM radio stations, and are likely to remain loyal to these media programs. This listener allegiance to existing regional AM and FM radio programming from regional service providers may slow the acceptance of SDARS. One potential solution to this problem would be to simply broadcast all regional programs to all subscribers. However, this would present a confusing array of uninteresting media programs to a typical user, and requires agreements with a multitude of rights holders and requires enormous system capacity. What is needed is a system and method for making regional broadcasts “appear” available on digital satellite broadcasts to those listeners within the reception area of the regional broadcast provider and to provide some local content to the SDARS customer via the system itself. The present invention satisfies that need.
SUMMARY OF THE INVENTION
In summary, the present invention describes a system and method for receiving regional media programs transmitted by regional media providers. One embodiment of the present invention comprises the steps of receiving a signal in a receiver disposed in one of a plurality of local broadcast regions within a national broadcast region, wherein the signal includes national media programs (optionally including a corresponding electronic program guide) intended for reception in the national broadcast region, and regional media programs (optionally including a corresponding electronic program guide) intended for reception only in the local broadcast regions, determining the local broadcast region, and providing only the regional media programs intended for reception in the determined local broadcast region.
In one embodiment, the apparatus comprises a receiver for receiving regional media programs in one of a plurality of local broadcast regions within a national broadcast region. The receiver comprises a tuner for receiving a first signal from a satellite, wherein the first signal comprises national media programs (and optional electronic program guides) intended for reception in the national broadcast region and regional media programs (and optional electronic program guides) intended for reception only in the local broadcast region, a second tuner module for receiving a second signal from a repeater serving the local broadcast region, the second signal comprising at least one regional media program and a local broadcast ID, a location module for determining the local broadcast region, and a controller module for providing only that local media programs intended for reception in the determined local broadcast region.
In addition to distributing regional media programs, the present invention provides a device and method for distributing channel and program information (both text and graphics) for existing analog radio services (such as the AM and FM services provided in the United States), and to enable the presentation of a uniform electronic program guide (EPG) to be provided for both the existing services and the new services. The invention provides EPG information for the existing services via a nationwide satellite broadcast (e.g. via SDARS) and also via a repeater network such as the SDARS terrestrial repeater network. The repeater network can simply rebroadcast the satellite broadcast, or alternatively, filter the national broadcast, store, and replay the newly created local multimedia information (television, audio, data, text, graphics, etc.) and EPG data solely to the local area. The EPG information for all channels (local AM, local FM, national and regional media programs) are received and displayed by the user's receiver.
Thus, the present invention allows accelerated acceptance of SDARS-like systems because customers can experience their familiar, favorite, AM and FM channels in the same “linear space” as the new channels. In one embodiment, the present invention also presents an EPG that has roughly the same detail regarding local and national stations. The present invention is also beneficial to existing media service providers, because it allows the media to currently broadcast on AM and FM channels to be provided to customers who would otherwise have been dissuaded by poor or marginal reception quality.
In a further embodiment, new regional programs are broadcast nationally and the locally re-broadcast repetitively via the repeater network. This reduces the local subscriber's “waiting time” for information of local interest.
BRIEF DESCRIPTION OF THE DRAWINGS
Referring now to the drawings in which like reference numbers represent corresponding parts throughout:
FIG. 1 is a diagram showing an overview of a media distribution system;
FIG. 2 is a block diagram showing a typical uplink configuration for a single satellite transponder;
FIG. 3A is a diagram of a representative data stream received from a satellite;
FIG. 3B is a diagram illustrating the structure of a data packet;
FIG. 4 is a diagram presenting a depiction of broadcast regions;
FIG. 5 is a block diagram of one embodiment of a repeater and a subscriber receiver;
FIG. 6A is a flow diagram illustrating two alternative embodiments of the present invention;
FIG. 6B is a flow diagram the audio repeater processing;
FIGS. 7A and 7B are flow charts presenting exemplary method steps used to practice one embodiment of the present invention; and
FIGS. 8A and 8B are flow charts presenting exemplary method steps useful in presenting an integrated EPG to the user.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
In the following description, reference is made to the accompanying drawings which form a part hereof, and which show, by way of illustration, several embodiments of the present invention. It is understood that other embodiments may be utilized and structural changes may be made without departing from the scope of the present invention.
FIG. 1 is a diagram illustrating an overview of a media program distribution system 100 . The media program distribution system 100 comprises a control center 102 in communication with an uplink center 104 via a ground link 105 . The control center 102 provides program material to the uplink center 104 , and coordinates with the subscriber receivers 110 A- 110 B to provide program services.
The uplink center 104 receives program material and program control information from the control center 102 , and using an uplink antenna 106 , transmits the program material and program control information to the satellite 108 . The satellite 108 receives and processes this information, and transmits the media programs and control information to subscriber receivers 110 A and 110 B, via downlinks 118 A and 118 B, respectively. A subscriber receiver antenna ( 112 A and 112 B, respectively) receives this information and provides a signal to the subscriber receivers 110 A and 110 B.
Subscriber receiver antenna 112 A and subscriber receiver 1120 A comprise a typically immobile subscriber installation 114 such as that which would be used in a home. Subscriber receiver antenna 112 B and subscriber receiver 110 B comprise a typically mobile subscriber installation 116 such as that which would be used in a vehicle. In addition to the direct broadcast from the satellite 108 to the subscriber receivers 110 A and 110 B as described above, the media program distribution system also comprises one or more repeaters 120 . The repeaters 120 receive broadcast signals from the satellite 108 and re-transmit the media programs in the broadcast signals to subscriber receivers 110 A and 110 B. Typically, the repeaters 120 are especially useful in mobile applications, since they can re-transmit the signals received from the broadcast satellites at different angle frequencies and with different modulation techniques that are complementary to the satellite delivery path.
In addition to the foregoing, there are existing media service providers 122 (i.e. existing AM and FM radio stations) that broadcast media programs via broadcast transmitters 124 to standard (i.e. AM and/or FM) receivers 126 . As shown in FIG. 1 , standard receivers 126 can be mobile or at a fixed location, such as a house.
The media program distribution system 100 can comprise a plurality of satellites 108 in order to provide wider terrestrial coverage, to provide additional channels, or to provide additional bandwidth per channel. In one embodiment of the invention, each satellite comprises a plurality of transponders to receive and transmit program material and other control data from the uplink center 104 and provide it to the subscriber receivers 110 A and 110 B (hereinafter collectively referred to as subscriber receiver(s) 110 ). However, using data compression and multiplexing techniques the program channel capabilities are far greater than the number of satellite transponders.
While the invention disclosed herein will be described with reference to a satellite based media program distribution system 100 , the present invention may also be practiced with terrestrial-based transmission of program information, whether by broadcasting means, cable, or other means. Further, the different functions collectively allocated between the control center 102 and the uplink center 104 as described above can be reallocated as desired without departing from the intended scope of the present invention.
Although the foregoing has been described with respect to an embodiment in which the program material delivered to the subscriber is audio program material, the foregoing method can be used to deliver program material comprising purely television, data or multimedia.
FIG. 2 is a block diagram showing a typical uplink configuration for a single satellite 108 transponder, showing how media programs are uplinked to the satellite 108 by the control center 102 and the uplink center 104 . FIG. 2 shows three audio channels, and a data channel from a computer data source 206 .
The audio channels are provided by a program source of audio material 200 A- 200 C (collectively referred to hereinafter as audio source(s) 200 ). The data from each audio program source 200 is optionally provided to encoders 202 A- 202 C (collectively referred to hereinafter as encoder(s) 202 ). The data channel which can include EPG data, can be subjected to a similar compression scheme by an encoder (not shown), but such compression is usually either unnecessary, or performed by computer programs in the computer domain (for example, text compression could be performed within the source computer). After encoding by the encoders 202 , the signals are converted into data packets by a packetizer 204 A- 204 F (collectively referred to hereinafter as packetizer(s) 204 ) associated with each source 200 .
The data packets are assembled using a reference from the system clock 214 (SCR), and from the conditional access manager 208 , which provides a control word to the packetizers 204 and to the controller 216 . The control word is used to determine which media program channels will be presented to the subscriber. Another processor 210 manages service channel IDs (SCIDs) for use in generating the data packets, and provides the SCIDs to the packetizers 204 and to the controller 216 . These data packets are then multiplexed into a serial stream and transmitted.
FIG. 3A is a diagram of a representative data stream. The first packet segment 302 comprises information from audio channel 1 (data coming from, for example, the first audio program source 200 A). The next packet segment 304 comprises computer data information that was obtained, for example from the computer data source 206 . The next packet segment 306 comprises information from audio channel 5 (from one of the program sources 200 ), and the next packet segment includes information from audio channel 1 (again, coming from program source 200 A). The data stream therefore comprises a series of packets from any one of the data sources in an order determined by the controller 216 . The data stream is encrypted by the encryption module 218 , modulated by the modulator 220 (typically using a QPSK modulation scheme), and provided to the transmitter 222 , which broadcasts the modulated data stream on a frequency bandwidth to the satellite via the antenna 106 . The subscriber receiver 110 receives these signals, and by scanning incoming packet headers for the desired SCIDs, reassembles the packets to regenerate the program material for each of the channels. As shown in FIG. 3A , null packets created by the null packet module 212 may be inserted into the data stream as desired to provide a continuous stream.
FIG. 3B is a diagram of a data packet. Each data packet (e.g. 302 - 316 ) is 147 bytes long, and comprises a number of packet segments. The first packet segment 320 comprises two bytes of information containing the SCID and flags. The SCID is a unique 12-bit number that uniquely identifies the data packet's data channel. The flags include 4 bits that are used to control whether the packet is encrypted, and what key must be used to decrypt the packet. The second packet segment 322 is made up of a 4-bit packet type indicator and other header information. The packet type identifies the packet as one of the four data types (video, audio, data, or null). When combined with the SCID, the packet type determines how the data packet will be processed. The next packet segment 324 comprises 127 bytes of payload data, which is a portion of the program provided by the program source 200 . The final packet segment 326 is data required to perform forward error correction.
FIG. 4 is a diagram showing a depiction of broadcast regions. The satellite 108 broadcasts signals to receivers disposed in an area hereinafter referred to as a national broadcast region 402 . Although the term “national” is used to refer to this broadcast region in this disclosure, the region need have no correlation whatsoever with national boundaries. As used herein, the national broadcast region 402 describes an area which may include multiple regions, in which broadcasts from one or more of the satellites 108 are intended to be received by terrestrial receivers disposed therein. The national broadcast region comprises one or more local broadcast regions 404 A- 404 C (hereinafter alternatively referred to as regional broadcast region(s) 404 ). Regional broadcast regions 404 are areas defined by the service area of regional media providers who, using regional media program transmitters 406 A- 406 C, broadcast regional media programs to listeners 408 A- 408 B within the respective service areas.
As described with respect to FIG. 1 , in the media program distribution system 100 the satellite 108 transmits media programs to listeners 410 outside any of the regional broadcast regions 404 directly by satellite 108 , and transmits media programs to listeners 408 A- 408 B inside the local broadcast regions directly and via repeaters 124 A- 124 C.
FIG. 5 is a block diagram of one embodiment of the repeater 120 and the subscriber receiver 110 . The repeater 120 comprises a repeater receiver 502 communicatively coupled to a repeater antenna 504 . The repeater receiver 502 comprises a tuner, demodulator, decoder, and demultiplexer, to receive signals from the satellite 108 . The satellite signal comprises national media programs (programs with primarily national interest) intended for reception in the national broadcast region and regional media programs (programs with largely localized interest) intended for reception in local broadcast regions 404 . In one embodiment, the signal from the satellite also comprises electronic program guide (EPG) information describing the satellite national media programs and regional media programs, and associating each with a media channel. The EPG information may also include information for local AM and FM stations. EPG-related data is supplied to a repeater EPG data processor 506 . Audio output is supplied to the processing module 507 . The outputs of the EPG data processor 506 and the processing module 507 are remultiplexed in the multiplexer 508 .
The multiplexer 508 accepts the EPG information and the audio data streams, and adds a local broadcast identifier (ID) to the data streams which are intended for reception in the local broadcast region serviced by the repeater 120 . This local broadcast ID tells each satellite receiver its location (e.g. if a given ID can be received, the receiver is, by definition, in that region as viewed by the satellite system). In one embodiment, the local broadcast ID is simply appended to the packets representing the data stream.
FIG. 6A is a flow diagram illustrating two embodiments of the repeater EPG processing of the present invention. In the first alternative embodiment, EPG data received from the satellite 108 is passed to the subscriber receiver 110 unchanged 602 , but a local market ID is appended 610 to the media programs to identify the repeater 112 location in the rebroadcast. In a second alternative embodiment, the regional media program EPG data is filtered 606 so that only the regional media programs for the local broadcast region 404 and neighboring local broadcast regions are stored in the repeater 112 . This filtered EPG information is transmitted to subscriber receivers. By filtering the EPG information so that only the EPG information for the local markets (and, optionally, the neighboring markets) is provided, additional transmission bandwidth becomes available. This additional bandwidth can be used to transmit the EPG data at a higher repetition rate in the local broadcast region, and, optionally, a lower repetition rate in the neighboring region 608 . Repetition rates may be further adjusted to account for local market demographics, the date and time of day. After the local broadcast ID is added to the regional media programs, the signals are provided to an encoder/modulator 510 , and thence to a repeater transmit antenna 512 for transmission.
FIG. 6B is a flow diagram illustrating the audio repeater processing. Input demultiplexing 612 is performed by the demux 502 . Metadata sent with each audio channel is scanned 614 for local broadcast IDs and compared 616 to local broadcast IDs of interest. Audio content with national interest (no local broadcast IDs) is then passed to the output multiplexer 508 . Audio content with local interest (local broadcast IDs) is filtered by comparing 616 IDs included with the broadcast against the local broadcast ID of the repeater 120 . Content of interest for the local market of the repeater is stored 618 (e.g. in random access memory or hard disk) and played out repeatedly in place of the local content intended for other local markets.
The subscriber receiver 110 comprises a first tuner module 514 and a second tuner module 516 , each communicatively coupled to a subscriber receiver antenna 112 . Alternatively, the first tuner module 514 and the second tuner module 516 could be coupled to different antennae. The first tuner module 514 comprises a tuner, a demodulator, a decoder, and a demultiplexer to receive the signal from the satellite 108 and separate that signal into an audio signal representing the media program on the user-selected channel, and EPG data. The second tuner module 516 comprises a tuner, a demodulator, a decoder, and a demultiplexer to receive the signal from the repeater 120 and separate that signal into an audio signal representing the media program selected on the user-selected channel, and EPG data from the repeater 120 .
The subscriber receiver 110 also comprises a location module 518 , which determines the local broadcast region 404 in which the subscriber receiver 110 is disposed. In one embodiment, the subscriber receiver 110 includes an AM/FM tuner 520 communicatively coupled to a suitable antenna 522 .
Existing FM broadcasts have recently added an elementary channel information feature known as the Radio Broadcast Data System (RBDS). This feature provides less than one Kbps on each channel, and can be used to provide information about the radio station. This information can include, for example, the regional media provider's call letters (e.g. KUSC), media program currently being transmitted (e.g. NPR's MORNING EDITION), media channel category (e.g. “blues,” “classical,” or “data”). The EPGs for new digital services such as SDARS will be much more extensive in terms of the data available about the media channel and individual programs.
The AM/FM tuner 520 provides audio data for presentation to the user, and may also provide RBDS data. The RBDS data received by the AM/FM tuner 520 is compared to a RBDS database 528 to determine the local broadcast region 404 in which the receiver is disposed. For example, many radio stations broadcast their letter designation (e.g. KUSC) on RBDS. In this case, the information transmitted by the satellite 108 can include a table having a mapping from the KUSC to the regional media provider at the University of Southern California, and local broadcast region of Los Angeles. This data, when received, can be stored in the database 528 and used to determine the local broadcast region 404 . The RDBS database can be periodically updated via the satellite 108 . In another embodiment, the subscriber receiver 110 includes a global positioning system (GPS) receiver 524 communicatively coupled to a suitable antenna 526 . The GPS receiver 524 can provide information regarding the position of the subscriber receiver 110 (for example, in the form of a latitude and longitude). In this embodiment, the location module 518 compares the latitude and longitude with a table mapping longitude and latitude to the local broadcast region 404 . The location module 518 provides the local broadcast region information to a controller module 530 and to an EPG data processing module 532 .
The controller module 530 uses the information provided by the location module 518 and the local market ID to determine which of the satellite's regional media programs should be presented to the user. Further, the EPG data processing module 532 uses the information provided by the location module 518 to determine which programs to present in an integrated EPG (presenting only those which are either national media programs or satellite or terrestrial regional media programs broadcast within the local broadcast region).
FIG. 7A is a diagram showing exemplary process steps used to practice one embodiment of the present invention. A signal is received 702 in a receiver 110 disposed in one of a plurality of local broadcast regions 404 A- 404 C within a national broadcast region 402 . The signal includes national media programs intended for reception in the national broadcast region 402 and regional media programs intended for reception only in the local broadcast region (e.g. 404 A). EPG information is also received 704 . The EPG information includes information regarding national media programs and regional media programs, and associates these programs with media channels that can be selected by the user by use of the EPG. Typically, the EPG information is broadcast on a periodic basis to update the EPG presented by the subscriber receiver 110 . Each succeeding broadcast of EPG information can comprise the entire EPG, or just the newer portions of the EPG. For example, the EPG information can be broadcast in a slow carousel, and can be stored in the subscriber receiver 110 for the current local broadcast region or all local broadcast regions. If updated EPG information is available, it is also received, as shown in blocks 706 and 708 .
As shown in FIG. 7B , the subscriber receiver 110 also receives 710 information identifying regional media providers providing services in the local broadcast region. In one embodiment, this is accomplished by receiving a table listing the AM and FM stations available in each RBDS market. This table can change several times a day, as the RBDS stations change the RBDS transmission content or power levels. The table can also be updated to reflect the impact of weather and/or time of day on the size and shape of the local broadcast region 404 or service area. The table can also include sufficient information to distinguish stations operating at the same frequency.
With regard to either the information identifying regional media providers or the EPG information, data compression techniques can be used to reduce the size of the transmissions.
Next, the subscriber receiver 110 determines 712 the local broadcast region 404 . As described above, this can be accomplished by the application of one or more techniques, including those that are identified below.
1) Identify the local broadcast region in which the receiver 110 is disposed by use of a look-up table mapping the latitude and longitude of the receiver 110 (as obtained from the GPS receiver 524 ) and local broadcast regions 404 . 2) Identify the local broadcast region in which the receiver 110 is disposed by comparing the local market IDs received from the repeater 112 . 3) Identify the local broadcast region by comparing received information regarding regional media providers (e.g. the call letters KUSC, as provided by RBDS) with a look-up table listing the expected information from each regional provider. 4) Identify the local broadcast region via a SDARS service authorization command. In this option, the satellite 108 transmits a command fixing the nominal location of the receiver.
Next, the subscriber receiver 110 presents 714 an integrated EPG having the national media programs and only the regional media programs that are intended for the local broadcast region identified using the logic in block 712 . This can be accomplished as shown in FIGS. 8A and 8B .
FIGS. 8A and 8B present illustrative method steps that can be used to present the integrated EPG. FIG. 8A presents one embodiment of the EPG processing for display of EPG elements provided by the satellite 108 . The latest error free data packets having EPG data describing the channels and media programs are received from either the satellite 108 or the repeater 112 and stored 802 . In one embodiment, each of the data packets transmitted to the subscriber receiver 110 includes a time tag that is used to determine which of the received EPG data packets represents the latest information. A determination as to the expected errors in the data packets can be performed using forward error control techniques described above. The resulting EPG is provided to a user interface 540 for presentation to the user. Subject to internal subscriber receiver 110 storage constraints, the received EPG channel and program information is stored 804 .
FIG. 8B presents one embodiment of the EPG processing for regional media services. A local market ID is determined 806 using GPS receiver 524 , the repeater 112 , or an RBDS-capable tuner 520 . Using a table broadcast by the satellite 108 or the repeater 112 , and the local market ID, the local broadcast region (and optionally, neighboring local broadcast regions) are determined 808 . This information is used to filter 810 data streams from the satellite 108 and the repeater 112 , passing media programs that are intended for the local broadcast region (and optionally, neighboring broadcast regions). Finally, the EPG is provided 812 to a user interface 540 for presentation to the user.
Thus, an EPG is displayed for all available AM, FM and SDARS channels. Where a large display is available, the EPG may comprise a guide grid relating to channels and media programs. Where a single line display is available, the user interface 540 may comprise a horizontally scrolled channel and current program information. Further, if requested by the user, the EPG may present program information for upcoming programs.
Returning to FIG. 7B , the subscriber receiver 110 accepts 716 a selection of a media program. If the media program is a national media program, the program is presented to the user. If the media program is a regional media program, a determination 718 may be made to determine if the selected local media program is intended to be received in the local broadcast region. If the media program is not intended to be received in the local broadcast region, a message indicating as such is provided to the user, and the media program is not provided. If the selected media program is intended to be received in the local broadcast region, the selected media program is provided 720 . In an alternative embodiment of the invention, the user is constrained to select media programs through the EPG, and the EPG presents only media programs that are available for viewing. In this embodiment, it is not required to evaluate the user's media program selection before providing it for use.
In a further embodiment, the user may select to receive all programs including regional programs intended for other regions. That is, the user may receive weather or other information for all localities rather than only for the user's local region.
CONCLUSION
The foregoing description of the preferred embodiment of the invention has been presented for the purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form disclosed. Many modifications and variations are possible in light of the above teaching. It is intended that the scope of the invention be limited not by this detailed description, but rather by the claims appended hereto. The above specification, examples and data provide a complete description of the manufacture and use of the composition of the invention. Since many embodiments of the invention can be made without departing from the spirit and scope of the invention, the invention resides in the claims hereinafter appended. | A method and apparatus for providing an integrated presentation of existing media program services and secondary media program services is described. The method comprises the steps of accepting a election of a secondary media program transmitted on a secondary media program channel; accessing a mapping to determine a primary media program channel associated with the selected secondary media program channel; commanding a first tuner module to receive conditional access information associated with the primary media program channel from the primary service provider; evaluating the conditional access information to determine if a second tuner is authorized to receive the secondary media program channel; and commanding a second tuner module to receive the secondary media program if the second tuner is authorized to receive the secondary media program channel. | 7 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is based upon and claims the benefit of priority from prior Japanese Patent Application No. 2004-120106, filed Apr. 15, 2004, the entire contents of which are incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to a system and method for managing vehicle inspections on a vehicle production line.
[0004] 2. Description of the Related Art
[0005] Conventional automobile production lines are classified into the following two types. In a first type, a plurality of inspecting stages are set for a vehicle. In each inspecting stage, inspection data is downloaded from a host computer into a personal computer. An inspector carries out inspections on the basis of the inspection data. The inspector then inputs the results of the inspections to the personal computer to transmit them to the host computer. In a second type, at the beginning of the inspections, an inspection instruction sheet is created by printing reference data required for inspections in the respective stages, on a sheet in a bar code form. The inspection instruction sheets are then attached to the vehicle. In the first stage, the bar code is read to obtain the reference data. Inspections are then carried out on the basis of the reference data. A bar code label indicating the results is then created and applied to the inspection instruction sheet. Thus, together with the vehicle, the inspection instruction sheet is transferred to the next stage (see, for example, Jpn. Pat. Appln. KOKAI Publication No. 2002-12177).
[0006] If any defect is found as a result of the inspections based on the inspection instruction sheet, it must be repaired in the subsequent stage (that is, a repair stage).
[0007] Further, during the stage of repairing the defect, a new defect may occur.
BRIEF SUMMARY OF THE INVENTION
[0008] It is an object of the present invention to provide a system and method for managing vehicle inspections in which repair information obtained during a repair stage of repairing a defect found in an inspection stage is collected so that the repaired part can be reliably re-inspected.
[0009] According to one aspect of the invention, there is provided a system for managing vehicle inspections, the system comprising a server used on a vehicle production line and including an inspection master database which stores inspection items for parts to be repaired; and a repair terminal and a repair checking terminal which communicate with the server via a LAN and which are used in a plurality of inspection stages,
wherein the server comprises: a transmitting section configured to extract, on the basis of repair information on a part to be repaired which is transmitted by the repair terminal, inspection items related to this part to be repaired, from the inspection master data, and to transmit the inspection items to the repair checking terminal as re-inspection items, and the repair checking terminal comprises: a display; and a display section configured to display, on the display, the re-inspection items for the part to be repaired which have been transmitted by the server.
[0015] Additional objects and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objects and advantages of the invention may be realized and obtained by means of the instrumentalities and combinations particularly pointed out hereinafter.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING
[0016] The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate embodiments of the invention, and together with the general description given above and the detailed description of the embodiments given below, serve to explain the principles of the invention.
[0017] FIG. 1 is a diagram showing the configuration of an inspection managing system according to an embodiment of the present invention;
[0018] FIG. 2 is a block diagram showing the hardware configuration of a server according to the embodiment;
[0019] FIG. 3 is a block diagram showing the hardware configuration of a master managing terminal according to the embodiment;
[0020] FIG. 4 is a diagram showing the hardware configuration of an portable inspection terminal, a portable repair terminal, and a repair checking portable terminal;
[0021] FIG. 5 is a flowchart illustrating a process executed by the master managing terminal according to the embodiment;
[0022] FIG. 6 is a flowchart illustrating a process executed by the server according to the embodiment; and
[0023] FIG. 7 is a flowchart illustrating a process executed by the portable repair checking terminal according to the embodiment.
DETAILED DESCRIPTION OF THE INVENTION
[0024] With reference to the drawings, description will be given of operations of an embodiment of the present invention. FIG. 1 is a diagram showing the configuration of a system for managing vehicle inspections. In the figure, reference numeral 1 denotes a LAN placed in a vehicle manufacturing plant. The LAN 1 connects to a server 2 , a master managing terminal 3 , and a plurality of access points 4 . Each of the access points 4 communicates wirelessly with a portable inspection terminal 5 a serving as an terminal inspection, a portable repair terminal 5 b serving as a repair terminal, and a portable repair checking terminal 5 c serving as a repair checking terminal; these portable terminals are mobile terminals located close to the access point 4 .
[0025] The portable inspection terminal 5 a is carried by an inspector 6 . Every time a predetermined process on a production line is finished, the portable inspection terminal 5 a is operated to inspect a plurality of sites or parts to be inspected which were integrated into an automobile 7 during the process.
[0026] The portable repair terminal 5 b is carried by a repairer to repair a defect found during the inspection stage, in a subsequent repair checking stage, the inspection stage using the inspecting portable terminal 5 a.
[0027] The portable repair checking terminal 5 c is carried by a repair checker during a repair checking stage of checking whether or not the defect repaired during the repair stage has been appropriately executed.
[0028] The server 2 is provided with an inspection master database 11 and an inspection result database 12 . The inspection master database 11 stores inspection item assignment information on parts to be repaired. The parts to be repaired mean parts in which defects found during the inspection stage have occurred. It is also necessary to inspect sites in which detects are likely to occur as a result of the repair of the parts in which the defects occurred. Such a site is called a site to be inspected. A set of a part to be repaired and a site to be inspected is called an inspection target item. The master managing terminal 3 sets inspection item assignment information for each part to be repaired. The server 2 also stores various operation applications 13 .
[0029] The inspection result database 12 stores the results of actual inspections.
[0030] As shown in FIG. 2 , the server 2 is provided with a central processing unit (CPU) 21 constituting a control section main body, a read-only memory (ROM) 22 that stores program data used by the CPU 21 to control each section, a random-access memory (RAM) 23 provided with a memory temporarily used by the CPU 21 to execute data transmission, reception, processing, or the like, a communication section 25 which transmits and receives data to and from the master managing terminal 3 via the LAN 1 and which transmits and receives data to and from the inspecting portable terminal 5 via the access point 4 , and an operation section 26 used for key inputs, display of indicators, and the like. The components of the server 2 are electrically connected together by a bus line 27 .
[0031] The master managing terminal 3 is operated by the manager of the production line. As shown in FIG. 3 , the master managing terminal 3 is provided with a CPU 31 constituting a control section main body, a ROM 32 that stores program data used by the CPU 31 to control each section, a RAM 33 provided with a memory temporarily used by the CPU 31 to execute data transmission, reception, processing, or the like and a memory storing a small amount of data, a communication section 34 which transmits and receives data to and from the server 2 via the LAN 1 , a keyboard provided with various keys to perform operations, a display 36 composed of a liquid crystal or the like and used for data display or the like, a printer 37 used to print required data, and a hard disk device 38 used to store a large amount of data. The components of the server 2 are electrically connected together by a bus line 39 .
[0032] As shown in FIG. 4 , each of the portable terminals 5 a to 5 c is provided with a CPU 51 constituting a control section main body, a ROM 52 that stores program data used by the CPU 51 to control each section, a RAM 53 provided with a memory temporarily used by the CPU 51 to execute data transmission, reception, processing, or the like and a memory storing a small amount of data, a liquid crystal display 54 used for data display, display of various types of information on the input screen, or the like, a touch panel 55 placed on the liquid crystal display 54 to input information to an input screen displayed on the liquid crystal display 54 , and a radio communication section 56 that transmits and receives data to and from the access point 4 by radio. The components of the portable terminal 5 a to 5 c are electrically connected together by a bus line 57 .
[0033] Using the master managing terminal 3 , the manager inputs, for each automobile to be manufactured, inspection information as to what inspections to be carried out and which sites or parts to be inspected in each step. Moreover, the manager inputs inspection item assignment information on a part to be repaired. As a result, in accordance with the processing shown in the flowchart in FIG. 5 , the inspection information and the inspection item assignment information on the part to be repaired are transmitted to the inspection master database 11 of the server 2 (step S 1 ).
[0034] Once the inspection information for each automobile to be manufactured and for each stage is set in the inspection master database 11 of the server 2 , the portable inspection terminal 5 a communicates wirelessly with the server 2 in each stage. On the basis of the inspection information transmitted by the server 2 , the portable inspection terminal 5 a displays an inspection screen on the liquid crystal display 54 . The results of inspections in each stage are input to the inspection screen.
[0035] Inspections are carried out using the portable inspection terminal 5 a, with the results of the inspections transmitted to the server 2 . Then, when the results of the inspections indicate that there is a defect in the automobile, the server 2 transmits the cause of the detected defect. The portable repair terminal 5 b is subsequently used to repair the defect.
[0036] For some defects, repair may result in the occurrence of a secondary defect. For example, if a defect in an instrument panel is found as a result of inspections carried out using the portable inspection terminal 5 a, replacing the instrument panel with a new one may result in a secondary defect in another part in association with the replacement. Consequently, after the repair of the defect, it is necessary to re-inspect other parts in which defects may occur as a result of the repair. This inspection is carried out in a repair checking stage, described later.
[0037] As described above in connection with the configuration, the inspection item assignment information for the part to be repaired has been input through the master managing terminal 3 . The inspection item assignment information relate to other parts to be re-inspected because defects may occur in them as a result of the repair. The inspection item assignment information contains a set of sites to be inspected and the contents and methods of inspections.
[0038] In the repair stage, the portable repair terminal 5 b transmits the information on the part to be repaired (that is, repair information) to the server 2 .
[0039] Upon receiving this information, the server 2 executes a process such as the one shown in FIG. 6 . Specifically, the server 2 determines whether or not there has been any part to be repaired input by the portable repair terminal 5 b (step S 11 ). If the result of the determination in step S 11 is “YES”, the server 2 transmits the inspection item assignment information on the part to be inspected to the portable repair checking terminal 5 c (step S 12 ).
[0040] Then, the portable repair checking terminal 5 c executes a process shown in the flowchart in FIG. 7 . Specifically, the portable repair checking terminal 5 c displays the received inspection item assignment information on its own liquid crystal display 54 (step S 21 ).
[0041] A repair checker views the display screen of the liquid crystal display 54 to input the results of the repair checks.
[0042] The terminal determines whether or not the results have been input (step S 22 ). If the result of the determination in step S 22 is “YES”, the terminal transmits the results of the inspections to the server 2 (step S 23 ).
[0043] For example, a display area in the upper part of the display screen of the portable repair terminal 5 b shows an inspection classification “A1”, an inspection content “noise”, an inspection target “power window”, and an inspection site “D seat side”. In other words, defect information is displayed indicating that there is noise in the power window.
[0044] Further, parts to be adjusted and repaired are shown in a display area in the lower part of the display screen of the portable repair terminal 5 b.
[0045] The portable repair checking terminal 5 c is provided with a display area that shows sites to be re-inspected in connection with the inspection target shown in the display area of the portable repair terminal 5 b, and a display area that shows sites to be inspected of peripheral parts in which secondary defects may occur as a result of the repair of the part to be repaired which is shown in the display area of the portable repair inspection terminal 5 b.
[0046] Buttons used to input the results of inspections are displayed at the right end of the display area showing the sites to be re-inspected.
[0047] Also at the right end of the display area that shows the sites to be inspected of the peripheral parts in which secondary defects may occur as a result of the repair of the parts to be repaired, buttons are shown which are used to input the results of inspections of the sites to be inspected of the peripheral parts in which secondary defects may occur.
[0048] When “All OK” is input as the results of the inspections of all the sites to be inspected of the peripheral parts in which secondary defects may occur as a result of the repair of the parts to be repaired, the input buttons located at the right end of the inspection area are enabled; the input buttons are used to input the results of the inspections.
[0049] As described above, in the repair checking stage, the automobile is automatically inspected for new problems that may occur in the repair stage of repairing defects found in the inspection stage. This makes it possible to reliably avoid oversights in secondary problems that may occur in the step of repairing defects.
[0050] In the description of the present embodiment, the portable inspection terminal is used as an inspection terminal, the portable repair terminal is used as a repair terminal, and the portable repair checking terminal is used as a repair checking terminal. Further, the system communicates with the server 2 via the access point 4 on the basis of the radio communication system. However, the present invention is not limited to this. It is possible to use an installed inspection terminal, repair terminal, and repair checking terminal which are set by the server 2 and LAN.
[0051] Moreover, the liquid crystal display 54 of the portable inspection terminal 5 a is of the touch panel type. However, the present invention is not limited to this.
[0052] Additional advantages and modifications will readily occur to those skilled in the art. Therefore, the invention in its broader aspects is not limited to the specific details and representative embodiments shown and described herein. Accordingly, various modifications may be made without departing from the spirit or scope of the general inventive concept as defined by the appended claims and their equivalents. | The present invention provides a system for managing vehicle inspections, the system including a server used on a vehicle production line and having an inspection master database which stores inspection items for parts to be repaired, and a repair terminal and a repair checking terminal which communicate with the server via a LAN and which are used in a plurality of inspection stages. The server includes a transmitting section which extracts, on the basis of repair information on a part to be repaired which is transmitted by the repair terminal, inspection items related to this part to be repaired, from the inspection master data, and which transmits the inspection items to the repair checking terminal as re-inspection items. The repair checking terminal includes a display, and a display section which displays, on the display, the re-inspection items for the part to be repaired which have been transmitted by the server. | 1 |
CROSS-REFERENCE TO RELATED APPLICATION(S)
This application is a continuation of U.S. patent application Ser. No. 10/321,318, filed Dec. 17, 2002, entitled “Natural Vitamin E Compositions with Superior Antioxidant Potency”, subject matter of which is incorporated herewith by reference.
FIELD OF THE INVENTION
This invention relates to a novel composition comprising natural d-alpha-tocopherol, mixed natural tocopherols (alpha-tocopherol, beta-tocopherol, gamma-tocopherol, delta-tocopherol), and tocotrienols (alpha-tocotrienol, beta-tocotrienol, gamma-tocotrienol, delta-tocotrienol) having a synergistic antioxidant activity more potent than the antioxidant activity of natural d-alpha-tocopherol.
BACKGROUND OF THE INVENTION
Vitamin E is a generic name for a family of four compounds (forms) of tocopherols and four compounds of tocotrienols. All eight compounds have a chromanol ring structure and a side chain. There are four tocopherol forms (alpha, beta, delta, and gamma) with a fully saturated side chain; and four tocotrienol forms (alpha, beta, delta, and gamma) having unsaturated side chains with double bonds at the 3′, 7′, and 11′ positions in the side chain. The four compounds of both tocopherols and tocotrienols differ from each other in the number and position of methyl groups in the aromatic chromanol ring. Alpha-isomers have all three methyl groups in the chromanol ring. Beta and gamma have tow methyl groups but at different positions in the aromatic chromanol ring. Delta has only one methyl group in the chromanol ring.
Recently, the term natural vitamin E has become synonymous with only alpha-tocopherol. The vitamin E compounds are light yellow oils at room temperature and are fairly stable to heat and acid and degrade with alkaline conditions, and when exposed to ultra violet light, and when exposed to the oxygen air.
Foods that are rich in vitamin E include dark green vegetables, eggs, fish, nuts, soy beans, vegetable oils, wheat germ, and whole-grain products. However, foods are commonly depleted of vitamin E due to processing, refining and storage. After absorption in the intestine, vitamin E is transported to the blood circulation by lipoproteins. As a fat-soluble vitamin, vitamin E is amenable for entry and storage in cell membranes.
The health beneficial effects of vitamin E are, in part, due to their antioxidant property. Vitamin E is the primary defense against cell membrane and DNA damage and protects LDL and other lipid-rich tissues against oxidation. Vitamin E prevents the oxidation of unsaturated and polyunsaturated fatty acids.
Tocotrienols, due to their unsaturated side chains, provide much stronger antioxidant effects and protect against oxidation of “bad” cholesterol, LDL, which, if oxidized, leads to buildup of plaques in arteries and increased risk of heart attack or stroke. The beneficial effects of tocotrienols also include cholesterol lowering, tumor suppressive effect, and inhibition of blood platelet aggregation.
Reactive oxygen species are of great interest in medicine because of the overwhelming evidence relating them to aging and various disease processes such as atherosclerosis, brain dysfunction, birth defects, cataracts, cancer, immune system decline, rheumatoid arthritis, and inflammatory bowel diseases. A complex antioxidant network, such as vitamin E, is effective to counteract reactive oxygen species that are detrimental to human life.
Research studies have indicated that major diseases that afflict humankind worldwide may be preventable by the intake of nutritional supplements, such as antioxidants. The term “antioxidant” nutritional agent has been applied to a number of specific nutrients; including vitamin E. Antioxidants use therefore has gained popularity to prevent disease and to promote health. These compounds are readily available, and non-toxic.
Antioxidants function by neutralizing the harmful effects of free radicals. Free radicals are unstable, highly reactive molecules that circulate in the bloodstream. Some of these free radicals result from lifestyle factors like environmental stress and strenuous exercise, as well as natural processes like aging. To become chemically stable, free radicals take electrons from other molecules in the body, a process that causes cell damage (oxidative damage). Antioxidants prevent oxidative damage by donating electrons to free radicals. As a fat-soluble vitamin, Vitamin E is amenable for entry and storage in cell membranes to react with free-radical molecules and reduce the damage they cause.
The normal metabolic processes release some free radicals that might cause oxidative damage to our body, but our body repairs most of the oxidative damage caused by these free radicals. However, if we flood our bloodstream with an unusually large number of free radicals, typically by smoking or by eating a high-fat diet, over time, oxidative damage can overwhelm the body's repair mechanisms, setting us up for degenerative diseases. Antioxidants protect cells from the damage caused by free radicals.
Insufficient vitamin E results in free radical mediated lipid peroxidation of membranes and their destruction. Vitamin E protects the skeletal muscles, nervous system, and retina of the eye from oxidation. Vitamin E is essential for normal immune function. Vitamin E mitigates the prostaglandin driven severity of inflammation, PMS and circulatory disorders. Vitamin E may reduce the toxicity of metals and protect against free radical promoting environmental pollutants such as ozone, oxides of nitrogen, drugs, alcohol and smoking. Aging is essentially oxidative deterioration of tissues. Since vitamin E can prevent or slow down reactions of such oxidative damage, vitamin E may slow the aging process. The importance of antioxidants stems from the number of diseases where they play a preventive role, such as heart disease, cancer, and eye disease.
Epidemiological studies suggest that low blood levels of vitamin E are associated with increased risk of development of degenerative diseases including coronary heart disease, Alzheimer's disease, cataracts, and certain types of cancer. Two epidemiological studies of more than 12,000 adults conducted at Harvard University found a 40 percent decrease in heart disease risk in subjects taking at least 100 I.U. of vitamin E daily. However, people taking a higher dose of vitamin E supplements with only alpha-tocopherol may not be realizing full benefit. This is further substantiated by a recent study indicating that gamma-tocopherol traps mutagenic electrophiles such as nitric oxide and complements alpha tocopherol.
Oral doses of vitamin E ranging from 50 to 400 International Units (I.U.) per day did not show any adverse effects in double-blind clinical studies. The recommended daily amount (RDA) is 8 to 10 mg per day for healthy adults. In the U.S., 400 I.U. soft gelatin capsules are the most popular dosage from vitamin E. To achieve the potency of a 400 I.U. capsule, a person needs to consume 450 g of sunflower seeds, 2.2 kg of wheat germ or 1.9 liters of corn oil totaling 8,000 calories daily.
Fat soluble vitamins, like vitamin E, are found in foods associated with lipids and are absorbed from the intestine with dietary fats. Therefore, vitamin E intake is recommended with a meal and normally 20 to 40 percent of the ingested vitamin E is absorbed. Multiple doses instead of a single dose of vitamin E taken daily with a meal seem to indicate increased absorption and utility in the body. In fact, a combination of tocopherols, tocotrienols and phospholipids emulsifier have been shown to be effective carrier of molecules for improved absorption. In cardiovascular clinical studies, 50 mg/day vitamin E was used for a period ranging from 1 to 8.2 years without any adverse effects. Vitamin E is the least toxic among the fat soluble vitamins. No evidence of detrimental effects of vitamin E is observed even at daily doses of 100 to 500 mg. Human studies at daily 240 mg doses of tocotrienols for 18 to 24 months did not indicate any adverse effects. Further animal studies show safety of tocotrienols up to 12,000 mg/day.
Recent research studies have shown that a balanced intake of a full spectrum of vitamin E (gamma-, alpha-, beta- and delta-tocopherols) is the best way to overall health benefits. Research also showed tocotrienols from rice bran to be superior in reducing the atherosclerosis Lesion size in mice, thereby providing a unique approach to promoting cardiovascular health.
Gamma-tocopherol, the principle form of vitamin E in the diet, has been scientifically proven to enhance the health benefits of alpha-tocopherol, and is superior in promoting cardiovascular, brain, and immune health.
Gamma-tocopherol was also found to be superior to alpha-tocopherol in protecting cells against peroxynitrite, a harmful chemical that alters DNA and causes cancer. The study suggested that vitamin E supplement should contain at least 20% gamma-tocopherol.
A nested case-control study involving men who developed prostate cancer and matched control subjects showed that men with high blood levels of gamma tocopherol had a significant reduction in the risk of developing prostate cancer. The study also found a significant protective association for high levels of selenium and alpha tocopherol only in men with high gamma-tocopherol concentration.
In a recent study, gamma-tocopherol and alpha-carotene were found to be significantly lower in plasma of coronary heart disease patients compared to healthy people, suggesting that the plasma level of gamma-tocopherol might represent a marker of atherosclerosis in humans.
In an in vivo study, gamma-tocopherol was found to enhance the bio-potency of alpha-tocopherol. Gamma-Tocopherol induced a marked increase in alpha-tocopherol concentrations in the serum and in nerve tissues, heart, liver, and muscle in rats fed diets containing both gamma-tocopherol and alpha-tocopherol more than those fed a diet containing alpha-tocopherol alone.
In an animal study involving spontaneously hypertensive rats, gamma-Tocotrienol was also found to prevent development of increased blood pressure, to reduce lipid peroxidation in plasma and blood vessels, and to enhance total antioxidant status including superoxide dismutase activity. A recent study also showed that supplementation with 100 mg/day tocotrienol-rich fraction of rice bran for a month resulted in a significant reduction in total cholesterol, LDL-cholesterol and triglycerides.
These studies demonstrated that a composition comprising a full spectrum of all forms of tocopherols and tocotrienols will provide greater health benefits of vitamin E than the only form alpha-tocopherol. New compositions of vitamin E comprising all forms of vitamin E were formulated to meet certain criteria: the desired 400 I.U., higher antioxidant potency than alpha-tocopherol, and comparable cost to the commercially marketed natural vitamin E.
Only recently have reliable analytical methods became available to quantitatively measure the total antioxidant capacities, such as oxygen radical absorbance capacity (ORAC) assay, to evaluate the potency of antioxidant formulations. The ORAC method utilizes a peroxyl radical generator and beta-phycoerythrin protein as an indicator of oxidation by measuring the fluorescence of the protein. The ORAC values are expressed as micromoles of Trolox (6-hydroxy-2,5,7,8-tetramethylchroman-2-one carboxylic acid) equivalents per liter of the sample and Trolox shows total inhibition of the peroxyl radical action.
The ORAC assay is a widely accepted method in the world for identifying the antioxidant potential in a sample. The samples can be a pure compound, blood plasma, various tissues and foods such as fruits, vegetables, or dietary supplements. The total antioxidant capacity is reflected from various antioxidants present in the sample and their interactions. The advantage of this assay is that it helps quantify the antioxidant potential value of a sample compared to other commercial samples.
Several other methods have been developed to measure the total antioxidant capacity of a sample. However, the peroxyl or hydroxyl radicals used in the ORAC assay as pro-oxidants make it different and unique from the other assays that involve oxidants that are not necessarily pro-oxidants. Further, substantial deficiencies of other methods have overcome in the ORAC assay. For example, the ORAC assay was compared to other assays and the ORAC assay seems to provide a better correlation to the antioxidant capacity. Therefore, the ORAC assay method provides a valuable tool with which a researcher can quickly determine the value of a particular antioxidant formulation, where increased potency and reduced cost are desired.
It is an object of the present invention to provide a soft gelatin capsule containing natural vitamin E (d-alpha-tocopherol) blended with an additional vitamin E compounds, specifically natural mixed tocopherols (alpha-, beta-, gamma-, delta-) and tocotrienols (alpha-, beta-, gamma-, delta-), to deliver a potent antioxidant vitamin E with superior oxygen radical absorbance capacity (ORAC) value.
It is a further objective of the present invention to enhance the antioxidant capacity of natural vitamin E (d-alpha-tocopherol) for the specific health benefit derived from supplementation with the novel formulation.
It is a further objective of the present invention to provide a more efficacious product to natural vitamin E (d-alpha-tocopherol) product currently available for consumption.
SUMMARY OF THE INVENTION
This invention relates to formulations comprising all forms of natural tocopherols and tocotrienols with enhanced antioxidant activities. These formulations were designed to provide 400 IU, based on one mg d-alpha-tocopherol equals 1.49 IU. The invention further relates to a soft gelatin formulation containing natural vitamin E as d-alpha-tocopherol, mixed tocopherols in the form Alpha, Gamma, Delta, Beta, and tocotrienols, with inseparable tocopherols, in the form of Alpha, Gamma, Delta, Beta. The formulation is contained in a soft gelatin capsule composed of gelatin, glycerin, and water. The formulation is designed to provide antioxidant protection for the cell lipid membrane, and protection against heart disease, cancer, and eye disease.
The antioxidant activities of natural d-alpha-tocopherol, mixed tocopherols and tocotrienols, and formulations comprising all forms of vitamin E were determined employing an improved oxygen radical absorbance capacity (ORAC) assay using fluorescein (FL) as a fluorescent probe, randomly methylated β-cyclodextrin (RMCD) to enhance solubility of lipophilic antioxidants in aqueous medium, 2,2′-azobis (2-amidino-propane) dihydrochloride (AAPH) as peroxyl radical generator, and Trolox as a standard in 75 mM phosphate buffer. The antioxidant activities expressed in μmole Trolox equivalent per gram of d-alpha-tocopherol (87%), mixed tocopherols (70%) and tocotrienols (30%) were found to be 1,293, 1,948 and 1,229; respectively. The data clearly indicate that mixed tocopherols possess higher antioxidant activity than d-alpha-tocopherol.
Vitamin E formulations comprising alpha-, beta-, delta-, and gamma-forms of tocopherols and tocotrienols with enhanced antioxidant activities were developed. All of these formulations provide 400 I.U., based on one mg of d-alpha-tocopherol equals 1.49 I.U. Some of these formulations showed antioxidant activities superior to d-alpha-tocopherol.
This patent discloses formulations comprising all forms of tocopherols and tocotrienols with enhanced antioxidant activities. These formulations provide 400 I.U., based on one mg d-alpha-tocopherol equals 1.49 I.U. Novel formulations of vitamin E comprising a full spectrum of all forms of vitamin E, which possess significantly higher antioxidant activity than alpha-tocopherol are disclosed.
Other features and advantages of the present invention will become more apparent from the following detailed description, which illustrate, by way of example, the principles of the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The antioxidant activity, commonly referred to as oxygen radical absorbance capacity (ORAC), of a lipophilic substance was measured employing a newly developed assay. This assay is based on the use of: (a) fluorescein (FL) as the fluorescent probe, (b) randomly methylated β-cyclodextrin (RMCD) as a molecular host to enhance the solubility of lipophilic antioxidants in aqueous solution, (c) 2,2′-azobis (2-amidino-propane) dihydrochloride (AAPH) as a peroxyl radical generator, and (d) 6-hydroxy-2,5,7,8-tetramethyl-2-carboxylic acid (Trolox) as a standard in 75 mM phosphate buffer (pH 7.4).
The antioxidant activities of vitamin E formulations comprising all compounds of tocopherols and tocotrienols were determined employing an improved oxygen radical absorbance capacity (abbreviated ORACFL-LIPO) assay using fluorescein (FL) as the fluorescent probe, randomly methylated α-cyclodextrin (RMCD) as the water solubility enhancer for lipophilic antioxidants in 75 mM phosphate buffer (pH 7.4).
In the presence of peroxyl radicals derived from AAPH, the indicator FL gradually loses its fluorescence. The antioxidant activity of a substance is measured by its ability to retain the fluorescence of FL in the presence of peroxyl radicals. The net protection of FL was measured as previously described by Ou et al.
Chemicals and Apparatus
Randomly methylated β-cyclodextrin (RMCD) was purchased from Cyclolab R&D Ltd. (Budapest, Hungary). Fluorescein (FL) and 6-hydroxy-2,5,7,8-tetramethyl-2-carboxylic acid (Trolox) were purchased from Aldrich (Milwaukee, Wis.). 2,2′-azobis (2-amidino-propane) dihydrochloride (AAPH) was obtained from Wako Chemicals USA (Richmond, Va.). 87% d-alpha-Tocopherol (containing 13% soy bean oil) and 70% mixed tocopherols (containing 30% soy bean oil) were purchased from Archer Daniels Midland. Each gram of 70% mixed tocopherols contains 114 mg d-alpha-tocopherol, 11 mg d-beta-tocopherol, 457 mg d-gamma-tocopherol, and 131 mg d-delta-tocopherol.
Tocotrienols oil was purchased from Oryza Oil and Fat Chemical Co. in Japan. Tocotrienols oil contains 35% total tocopherols and tocotrienols (12.6% gamma-tocotrienol, 7.2% alpha-tocotrienol, and 12.7% alpha-tocopherol). Palm oil containing 50% total tocopherols and tocotrienols (10% alpha-tocopherol, 11% alpha-tocotrienol, 20% gamma-tocotrienol, and others) was obtained from Carotech (Edison, N.J.).
All other standards were commercially available form Sigma or Aldrich. All ORAC analyses were performed on a COBAS FARA II analyzer (Roche Diagnostic System Inc., Branchburg, N.J.) using an excitation wavelength of 493 nm and an emission filter of 515 nm.
Sample Preparation
Approximately 0.5 g of sample was dissolved in 20 mL of acetone. An aliquot of sample solution was appropriately diluted with 7% RMCD solvent (w/v) made in a 50% acetone-water mixture (v/v) and was shaken for 1 hr at room temperature on an orbital shaker at 400 rpm. The sample solution was ready for analysis after further dilution with 7% RMCD solvent.
Automatic ORAC Assay
The automated ORAC assay was carried out on a COBAS FARA II spectrofluorometer centrifugal analyzer as previously described (9). With the exception of samples and Trolox standards, which were made in 7% RMCD solvent, all other reagents were prepared at 75 mM phosphate buffer (pH 7.4). In the final assay mixture (0.4 mL total volume), FL (6.3×10 −8 M) was used as a target of free radical attack and AAPH (1.28×10 −2 M) was used as a peroxyl radical generator. 7% RMCD was used as the blank, and Trolox (12.5, 25, 50, and 100 μM) was used as the control standard. The analyzer was programmed to record the fluorescence of FL every minute after the addition of AAPH. All measurements were expressed relative to the initial reading. Final results were calculated using the differences of areas under the FL decay curves between the blank and a sample. These results were expressed as micromoles Trolox equivalent (TE) per gram, as previously described by Ou et al.
The antioxidant activity, commonly referred to as oxygen radical absorbance capacity (ORAC), of a lipophilic substance was measured employing a newly developed assay. This assay is based on the use of: (a) fluorescein (FL) as the fluorescent probe, (b) randomly methylated α-cyclodextrin (RMCD) as a molecular host to enhance the solubility of lipophilic antioxidants in aqueous solution, (c) 2,2′-azobis (2-amidino-propane) dihydrochloride (AAPH) as a peroxyl radical generator, and (d) 6-hydroxy-2,5,7,8-tetramethyl-2-carboxylic acid (Trolox) as a standard in 75 mM phosphate buffer (pH 7.4).
In the presence of peroxyl radicals derived from AAPH, the indicator FL gradually loses its fluorescence. The antioxidant activity of a substance is measured by its ability to retain the fluorescence of FL in the presence of peroxyl radicals. The net protection of FL was determined as previously described by Ou et al.
The ORAC value was calculated as μmole Trolox equivalent per gram sample (μmole TE/g); one gram of sample has antioxidant activity equals to how many μmole Trolox. The μmole Trolox equivalent per 400 I.U. of the sample is calculated as follows:
μmole TE/400 I.U.=μmole TE/g×total weight in grams of vitamin E formula which gives 400 I.U.
Tables (1) and (2) list the ORAC data expressed in μmole Trolox equivalent (TE) per gram of tested antioxidant sample. The formulations in Table (2) differ from those in Table (1) in that the Table (2) formulations further include Palm Oil and there is a slight modification in the ingredients of Formula 2 in Table (2) as compared to Formula 2 in Table (1). The results of data in Table (1) showed that the synthetic vitamin E acetate showed no antioxidant activity under current experimental conditions, supporting the essential role of the phenolic type hydroxyl for radical trapping antioxidant activity of vitamin E.
The IUs (International Unit) of a sample are based on one mg of alpha-tocopherol equals 1.49 IU.
The following are the percentage of alpha-tocopherol and the corresponding IUs in each ingredient used in the formulations listed in Tables (1) and (2):
(a) Natural vitamin E contains 87% alpha-tocopherol, which means that each gram of natural E contains 870 mg alpha-tocopherol×1.49=1300 IU, i.e. natural vitamin E contains 1300 IU per gram
(b) 90% Mixed tocopherols contains 6.8% alpha-tocopherol, which means one gram of 90% mixed tocopherols contains 68 mg alpha-tocopherol×1.49=101 IU, i.e. 90% mixed tocopherols contains 101 IU per gram
(c) 70% Mixed tocopherols contains 11.4% alpha-tocopherol, which means one gram of 70% mixed tocopherols contains 114 mg alpha-tocopherol×1.49=170 IU, i.e. 70% mixed tocopherols contains 170 IU per gram
(d) 30% Tocotrienols (Oryza) contains 13% alpha-tocopherol, which means one gram of 30% tocotrienols contains 130 mg alpha-tocopherol×1.49=200 IU, i.e. 30% tocotrienols contains 200 IU per gram
(e) 50% Tocotrienols (Carotech) contains 10% alpha-tocopherol, which means one gram of 50% tocotrienols contains 100 mg alpha-tocopherol×1.49=150 IU, i.e. 50% tocotrienols contains 150 IU per gram
TABLE 1
Antioxidant activities of vitamin E formulations f
μmole
Sample
μmole TE/g
TE/400 IU g
d-alpha-Tocopheral (87%), 1300 IU
1,293 ± 64
398
Tocotrienols (30%) (Oryza), 134 IU
1,229 ± 20
Mixed Tocopherols (70%), 120 IU
1,948 ± 76
Alpha-Tocopherol Acetate
14 ± 10
Formula-1
2,036 ± 116
1,063
Formula-2
1,735 ± 25
786
Formula-3
1,460 ± 156
530
Formula-4
1,303 ± 45
434
Table (1) notes:
f The following are the composition of each formula listed in Table (1) which gives 400 IU:
Formula-1: 307 mg alpha-tocopherol (87%), 15 mg tocotrienols (30%), 200 mg mixed tocopherols (70%).
Formula-2: 293 mg alpha-tocopherol (87%), 10 mg tocotrienols (30%), 150 mg mixed tocopherols (70%).
Formula-3: 303 mg alpha-tocopherol (87%), 10 mg tocotrienols (30%), 50 mg mixed tocopherols (70%).
Formula-4: 316 mg alpha-tocopherol (87%), 16.5 mg tocotrienols (30%).
g μmole TE/400 IU = μmole TE/g × total weight in grams of vitamin E formula which gives 400 IU
TABLE 2
Antioxidant activities of vitamin E formulations h
μmole
Sample
μmole TE/g
TE/400 IU i
d-alpha-Tocopheral (87%), 1300 IU
1,293 ± 80
413
Tocotrienols (30%, Oryza)
1,361 ± 88
Tocopherols (50%, Carotech)
3,112 ± 232
Mixed Tocopherols (70%)
2,256 ± 248
Mixed Tocopherols (90%)
2,674 ± 146
Formula-2
1,945 ± 113
881
Formula-2a
1,857 ± 60
860
Formula-2ab
1,825 ± 120
872
Formula-2ac
1,828 ± 90
837
Table (2) Notes:
h The following are the composition of each formula listed in Table (2) which gives 400 IU:
Formula-2: 293 mg alpha-tocopherol (87%), 10 mg tocotrienols (30%), 150 mg mixed tocopherols (70%).
Formula-2a: 293 mg alpha-tocopherol (87%), 10 mg tocotrienols (30%), 160 mg mixed tocopherols (70%).
Formula-2ab: 293 mg alpha-tocopherol (87%), 10 mg tocotrienols (30%), 175 mg mixed tocopherols (70%).
Formula-2ac: 293.5 mg alpha-tocopherol (87%), 4.3 mg tocotrienols (50%), 160 mg mixed tocopherols (70%).
i μmole TE/400 IU = μmole TE/g × total weight in grams of vitamin E formula which gives 400 IU
Data in table (1) revealed that alpha-tocopherol (87%) had a value of 1,293 μmole Trolox equivalent (TE) per gram, from this data one can calculate the μmole TE of 400 I.U. of alpha-tocopherol (87%) to be 398 (307.7 mg alpha-tocopherol is equivalent to 400 I.U.). Similarly, the μmole TE per 400 I.U. of each vitamin E formula can be calculated, and the results are given in table (1). As can be seen from data in table (1), the antioxidant activities of natural vitamin E formulae 1, 2 and 3 are higher than that of natural d-alpha-tocopherol (87%) at its specific concentration in the specified formula. Similar relative antioxidant activities were also obtained with tocotrienols from either Palm Oil or Oryza Oil as shown by the formulations in Table (2). These results indicate that the various isomers of natural tocopherols and tocotrienols could enhance the antioxidant activity of natural vitamin E (d-alpha-tocopherol). A recent study showed that a combination of alpha-, gamma-, and delta-tocopherols in a concentration found in nature is more potent than alpha-, gamma-, and delta-tocopherol alone in enhancing nitric oxide release, and inhibiting human platelet aggregation and lipid peroxidation.
The biological activity of vitamin E has generally been associated with its well-defined antioxidant property, specifically against lipid peroxidation in biological membranes. Therefore, it is anticipated that enhancing the antioxidant property of vitamin E as well as the full spectrum of various vitamin E forms might provide better health benefits than just alpha-tocopherol.
The antioxidant activities of alpha-tocopherol, mixed tocopherol and tocotrienols, and vitamin E formulations comprising all forms of tocopherols and tocotrienols were determined employing an oxygen radical absorbance capacity assay suitable for lipophilic antioxidants. The results of this study clearly indicate that mixed tocopherols possess higher antioxidant activity than d-alpha-tocopherol.
Vitamin E formulations, providing 400 I.U., comprising various forms of tocopherols and tocotrienols with enhanced antioxidant activities were developed. Some of these formulations showed antioxidant activities superior to d-alpha-tocopherol.
Formula-1 and Formula-2 were found to possess a much higher ORAC value than that of natural vitamin E (d-alpha-tocopherol). Formula-3 also showed an increase (25%) in its antioxidant activity as compared to alpha-tocopherol. Formula-4 showed slightly higher antioxidant activity that alpha-tocopherol. Formulae-1, -2, -3 contain alpha-tocopherol, mixed-tocopherols and tocotrienols, whereas Formula-4 contains only alpha-tocopherol and tocotrienols. As mentioned above, mixed tocopherols provide additional health benefits, therefore, Formula-1 or Formula-2 would be recommended since they contain all natural mixed tocopherols and tocotrienols and possess significantly higher antioxidant activity than alpha-tocopherol, and their cost is comparable to the widely marketed natural d-alpha-tocopherol. Each gram of 70% mixed tocopherols contains 114 mg d-alpha-tocopherol, 11 mg d-beta-tocopherol, 457 mg d-gamma-tocopherol, and 131 mg d-delta-tocopherol. From these data, the amount of gamma-tocopherol in
Formula-1 and Formula-2 is calculated to be 24% and 21%; respectively. These values are in accordance with the recommended amounts of gamma-tocopherol in vitamin E supplement. This study was published in Proceedings of the national Academy of Science, USA (1997), and suggested that vitamin E supplement should have at least 20% gamma-tocopherol. Formula-3, on the other hand, contains only 9% gamma-tocopherol.
In one preferred embodiment, the invention comprises a composition of natural vitamin E with enhanced antioxidant activity, comprising: (a) 55 to 85 % by weight of d- alpha-tocopherai; (b) 10 to 40 % by weight of mixed tocopherals; and (c) 2 to 3 % by weight of tocotrienols. In another embodiment, the mixed tocopherols comprise 70% tocopherols in the amounts of 5 to 15 % alpha-tocopherol, 1 to 3 % beta-tocopherol, 30 to 50 % gamma-tocopherol, and 10 to 20 % delta- tocopherol. In another embodiment, the mixed tocopherols comprise 90% tocopherols in the amounts of 10 to 20 % alpha- tocopherol, 2 to 4 % beta-tocopherol, 50 to 80 % gamma-tocopherol, and 10 to 20 % delta- tocopherol. In another embodiment, the tocotrienols are obtained from rice oil and said tocotrienols contain 10 to 15 % alpha- tocopherol, 10 to 12 % alpha-tocotrienol, 10 to 12 % gamma-tocotrienol, and 2 to 10 % other tocopherols and tocotrienols. In another embodiment, the tocotrienols are obtained from palm oil and said tocotrienols contain 8 to 14 % alpha- tocopherol, 8 to 14 % alpha-tocotrienol, 15 to 30 % gamma- tocotrienol, and 5 to 10% delta-tocotrienol. | Compositions for increased antioxidant potency of natural vitamin E (d-alpha-tocopherol), comprising alpha-, beta-, delta-, and gamma-forms of tocopherols and tocotrienols are disclosed. All of these compositions provide 400 International Units (IU), based on one mg of d-alpha-tocopherol provides 1.49 IU. These compositions showed antioxidant activities superior to natural d-alpha-tocopherol. These compositions are designed to provide protection of the cell membrane lipid layer, and protection against heart disease, cancer, and eye disease. | 0 |
RELATED APPLICATION DATA
This application is a continuation of application Ser. No. 13/231,681, filed Sep. 13, 2011, now pending,
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to a terrestrial communications system for mobile and portable devices, with possible applications in peer-to-peer communication systems. More specifically, the present invention relates to a spoke-and-hub communications system with increased user capacity by allowing frequency re-use through the use of multiple polarities, frequency slots, and directions organized through “unique waveforms” to radiate one signal.
2. Description of Related Art
Recent demand for terrestrial wireless communications methods such as WiFi and WiMax through portable devices such as iphones, ipods, bluetooth have increased dramatically. The increased use of such devices has resulted in a proliferation of IP-based products using fibers and satellites for back-bone or transport applications. On the other hand, high-speed access communications to handheld devices typically emanate from small wireless antennas that basically radiate and receive in broad beams with near omni-directional radiation patterns. Effective spectrum utilization becomes more and more important because of the expeditious increase of demand for wireless “access” communications.
Ever increasing demand for a finite amount of spectrum has made it one of the most important resources in wireless communications. Therefore, there have been schemes to increase spectrum utilization efficiency, such as orthogonal frequency-division multiplexing (OFDM) [1]-[3], cellular frequency reuse, and dual-polarization frequency reuse [4], [5]. OFDM is an attractive technique for digital transmission, as spectrum utilization efficiency can be increased by the orthogonal frequency spacing and signal bands' overlapping. Dual-polarization frequency reuse systems, which utilize both linear and circularly polarized electromagnetic (EM) waves that are orthogonal to each other, have been demonstrated in many satellite communications applications to double system capacity for fixed wireless (i.e. Wi-Fi, WiMax) and mobile (i.e. 3G and 4G systems for cell phones) systems. However, these polarization diversity systems are subject to system performance degradation due to cross polarizations and signal fading.
Linear-polarized (LP) systems feature two polarization directions of vertical polarity (VP) and horizontal polarity (HP). Similarly, circular-polarized systems also feature two polarization directions of right hand circular polarity (RHCP) and left hand circular polarity (LHCP).
In principle, transmission through orthogonal polarization carriers doubles the system capacity. However, practical use for portable devices is hard to achieve due to a user's dynamic motions, propagation impairments, antenna imperfections, among other things. The propagation impairments, such as rainfall attenuation, depolarization, and cross-polarization interference (CPI), deteriorate the signal transmission in the satellite-earth station links. Some compensation methods were reported in the literature [4]. Furthermore, the problems will become complicated by multipath fading effects when transmitting in a terrestrial environment. Although some schemes such as equalization and diversity are proposed to overcome such problems, their complicated nature prevents them from being a practical solution. The present invention aims to adopt the concept of wavefront multiplexing to more efficiently utilizing spectrum in polarization diversity.
Since the advent of low cost integrated Global Navigation Satellite Systems (GNSS) receivers such as the Global Positioning System (GPS) in addition to the usage of commercial off-the-shelf Micro-Electro-Mechanical Sensor (MEMS) accelerometers and gyroscopes, estimation of the “orientations” and motion trends of individual personal portable devices with respect to a fixed coordination system has become practical and affordable, as evidenced by their proliferation to the previously mentioned portable devices. GNSS and related technologies are satellite-based geo-location systems. There are other non-satellite based geo-location systems which may become cost effective, with small size, weight and power (SW&P) to be implemented in portable devices. The small-sized MEMS inertial measurement unit (IMU) provides the raw IMU data through a serial interface to a processor board where the inertial navigation solution and integrated GNSS/IMU with a Kalman filter is generated. Thus, polarizations diversity for better spectrum utility can be implemented with low cost and reliable processing techniques for consumer wireless communications markets, such as those featuring 3g and 4g mobile devices as well as WiFi and WiMax fixed devices.
Wavefront multiplexed frequency re-use methods via polarization diversity take advantage of incompatibilities among the two polarity formats (such as LP versus CP) to implement “orthogonality” among multiple waveforms used by different user signals that are sharing the same frequency assets. The conventional performance degradations such as cross polarizations of a CP waveform to a LP hub therefore become part of the WF muxed waveforms and operational features. The orthogonality among multiple user signals is no longer solely dependent on orientations of the portable user devices.
Compatible polarization configurations between user terminals and hub and/or cell tower assets are essential to efficient wireless links. It is generally true to efficiently utilizing polarization diversity that the LP polarized user terminals will use LP hubs and/or cell towers, and CP user terminals relay data via CP hubs and/or cell towers. When LP wireless portable terminals communicating to and from a CP hub and/or cell tower, their antenna polarizations must be configured accordingly emulating CP terminals, to prevent 3 dB SNR losses in receiving (Rx) functions on the one hand, and not to generate unwanted radiations in transmitting (Tx) functions on the other hand.
Our approaches to these issues are very different than those of polarization re-configuration, and may not require users to switch polarizations on their equipment at all. Linearly Polarized (LP) users can use their existing terminals to relay data to CP hubs and/or cell towers. There are no spectrum asset losses due to the incompatibility. It is how we re-organize the CP spectrum assets via operation of hubs and/or cell towers to make the “incompatibility” operationally possible. It is therefore a result of our invention that linearly polarized hubs or cell towers can be accessed and efficiently utilized by circularly polarized user terminals, and vice versa. We will illustrate how to use LP hubs to access CP portable devices efficiently in this application. It would be obvious that a person with ordinary skills in the art can derive similar techniques using CP hubs to access LP portable devices.
The invention relates to grouping two orthogonally polarized communications channels (e.g. HP and VP in linear polarities) with a common frequency slot on a hub or cell tower through Wave-Front (WF) Multiplexing (muxing) techniques for user portable terminals with incompatible polarization formats (e.g. RHCP and LHCP in circular polarities). The grouping method is extendable to multiple pairs of communications channels assets with both (LP) polarization formats with various frequency slots on different hubs or cell towers.
One of the approaches utilized by the present invention is the concept of virtual link, which utilizes N communications links organized by Wavefront (WF) Multiplexing (Muxing). A WF carrying a signal stream features a fixed spatial phase distribution among selected N parallel links, which support up to N orthogonal WFs carrying N independent signals concurrently from a source to a destination. The virtual link techniques are referred to as Orthogonal Wave-Front Diversity Multiplex (OWFDM), and the enabling signal structures as OWFDM waveforms.
Virtual links can also be applied for satellite communications transporting data within a fields of view common to selected transponders. Our proposed “Polarization Utility Waveforms” can successfully deliver signals via LP transponding satellites using CP ground terminals, and vice versa. They are engineered via techniques of signals spreading over multiple transponders. The waveforms may look like OFDM waveforms and may also appear as MIMO formats, but are not. They are subsets of OWFDM waveforms and may feature unique format interconnecting OFDM and MIMO through an orthogonal signal structure.
Virtual links can also be applied for terrestrial communications for last mile connectivity as well as transporting means from N sources to M destinations. Our proposed “Polarization Utility Waveforms” can successfully uploading signals to CP hubs and/or cell towers using LP portable devices terminals, and vice versa. They are engineered via techniques of signals spreading over multiple communications channels in the selected hubs and/or cell towers. The waveforms may look like OFDM waveforms and also appear as MIMO formats, but they are not.
It can be shown that WF muxing/demuxing techniques are powerful tools for path length equalizations among parallel paths/channels. SDS has applied these techniques for various applications; (1) Power combining from multiple transponders from the same satellites and/or different transponding satellites [6], (2) back channel equalization for ground based beam forming process in satellite applications [7], and (3) Distributed data storage [8].
Uniqueness of the OWFDM
Unlike OFDM for commercial wireless communications which feature waveforms with multiple orthogonal sub-carriers uniformly distributed in a frequency band, our proposed OWFDM techniques will spread transmitting (Tx) signals into multiple channels with a unique phase distribution pattern, referred to as a wavefront (WF). These channels may be assigned to different frequency slots, time slices, polarizations, and/or directions when these “communications assets” become available. The selected multi-dimensional waveforms may be dynamic and reconfigurable. There will always be embedded pilot signal streams through the same propagating paths but distributed in phase distribution patterns orthogonal to the one which carries the desired signal stream.
In general, the OWFDM waveforms must meet existing polarization and frequency convention restrictions. At a portable device, transmitting (Tx) signals may be preprocessed by a WF multiplexer (muxer), which coherently spread signals into multiple channels concurrently in a form of orthogonal structure in a selected N-dimensional domain. The generated orthogonality is among multiple wavefronts (WFs). With N parallel propagating channels, there are N-orthogonal WFs available. Probing signal streams may be attached to at least one of them. The remaining WFs are available for various Tx signal streams.
Signals that originate from a portable device propagating through various uplink carriers/paths, and arriving at designated hubs and/or cell towers feature differential phase delays, Doppler drifts, and amplitude amplifications/attenuations.
Post processing implemented at receiving (Rx) site will equalize the differential phase delays, frequency drifts and amplitude attenuations among signals through propagating paths. Calibrations and equalizations take advantages of embedded probe signals and iterative optimization loops. There are not feedbacks required through back channels, As a result of equalizations, the Rx WFs become orthogonal, and the attached signals streams are then precisely reconstituted by the WF demuxer.
SUMMARY OF THE INVENTION
The present invention pertains to a set of waveforms taking advantage of polarization incompatibilities between CP and LP signals, allowing portable devices to access available hub (and/or cell tower) communications assets when user portable or fixed terminals are not polarization-compatible. We will present the operational concepts and associated mechanisms to allow CP user terminals to access LP spectrum assets in hubs and/or cell towers (as well as LP user terminals to access CP spectrum assets) without sacrificing spectrum utility efficiencies and capacity.
The Wavefront multiplexed (WF muxed) polarization diversity methods as described with the present invention may be utilized for peer-to-peer communications to enhance capacity so long as user terminals on both ends of a link are not compatible in polarization formats. For example, when a transmitting device on a Bluetooth link uses a RHCP format, the device on the receiving side of the Bluetooth link will use both HP and VP (two components of LP format). The same transmitting device may use both RHCP and LHCP, therefore capturing additional 100% channel capacity and delivering 100% more data to the receiving side using the polarization diversity methods as described with the present invention.
Additionally, special OWFM waveforms are constructed under the constraints that all the user terminals feature only one of the two available CP options, while the hub and/or cell tower spectrum assets feature both LP channels of separated transceivers (transmitters and receivers) in a hub and/or cell tower. As a result, the targeted LP hub and/or cell tower spectrum assets support not only regular LP users but also additional CP customers without power and bandwidth capacity loss due to the polarization incompatibility.
Additional benefits include providing for dynamic resource allocation capability such as downlink power, or equivalently D/L EIRP (equivalent isotropically radiated power). Various user frequency channels in different transceivers are grouped and utilized by multiple users via OWFDM. The combined “power” assets can be dynamically assigned to any of the users as long as the total power output is constant. Current systems allow for two independent CP users to access conventional 100 mW CP channels separately, with the constraint that each user may only draw a maximum of 100 mW. However, with the present invention, when the same users access 100 mW LP channels organized by OWFDM, the first user may draw 160 mW while the second user may only need to draw 40 mW. Dynamic power requirements may mean that the first user no longer needs to transmit, allowing the second user to effectively use all 200 mW of equivalent power, or a 3 dB gain on equivalent EIRP.
These and other features of the present invention will become apparent from the following description of the invention, when viewed in accordance with the accompanied drawings and appended claims.
REFERENCES
1. Ramjee Prasad, “OFDM for wireless communications systems” (Google eBook) Artech House, 2004
2. Ming Jiang, “Multiuser MIMO-OFDM for Next-Generation Wireless Systems,” Proceedings of the IEEE, Volume: 95 Issue: 7 Jul. 2007
3. Ye G. Li, Jack H. Winters, and Nelson R. Sollenberger, “MIMO-OFDM for Wireless Communications: Signal Detection with Enhanced Channel Estimation,” IEEE Trans. On Communications, vol. 50, no. 9, September 2002
4. T. S. Chu, “Restoring the orthogonality of two polarizations in radio communication systems I,” Bell Syst. Tech. J ., vol. 50, no. 9, pp. 3063-3069, November 1971.
5. U.S. patent application Ser. No. 12/847,997; “Polarization Re-alignment for Mobile Satellite Terminals,” by Frank Lu, Yulan Sun, and Donald C. D. Chang; Filing on Jul. 30, 2010.
6. U.S. patent application Ser. No. 12/462,145; “Communication System for Dynamically Combining Power from a Plaurality of Propagation Channels in order to Improve Power Levels of Transmitted Signals without Affecting Receiver and Propagation Segments,” by D. Chang, initial filing on Jul. 30, 2009.
7. U.S. patent application Ser. No. 12/122,462; “Apparatus and Method for Remote Beam Forming for Satellite Broadcasting Systems,” by Donald C. D. Chang; initial filing May 16, 2008
8. U.S. patent application Ser. No. 12/848,953. “Novel Karaoke and Multi-Channel Data Recording/Transmission Techniques via Wavefront Multiplexing and Demultiplexing,” by Donald C. D. Chang, and Steve Chen Initial Filing on Aug. 2, 2010
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 depicts a block diagram of a LP hub accessed by two CP terminals for independent data stream relay to terrestrial communications networks. It also displays return-links from two users to a hub.
FIG. 2A depicts a handheld device in a receiving mode with a digital beam forming (DBF) process capable of performing dynamic polarization realignment, which is based on the knowledge of orientation and location of the handheld device and potential hub locations with respect to common local fixed coordinates.
FIG. 2B illustrates a handheld device in a transmitting mode with a digital beam forming (DBF) process capable of performing dynamic polarization realignment, which is based on the knowledge of orientation and location of the handheld device and potential hub locations with respect to common local fixed coordinates.
FIG. 3 illustrates the corresponding forward links for the two users in FIG. 1 .
FIG. 4 illustrates the corresponding forward links for one user in FIG. 1 but utilizing both RHCP and LHCP.
FIG. 5A depicts two mathematic matrixes: a 2-to-2 wavefront muxing matrix for two signals processing and a 4-to-4 mathematic matrix. The symmetric 2-to-2 matrix is constructed under the constraints that support user terminals featuring only one of the two available CPs. The symmetric 4-to-4 matrix is constructed under the constraints that support user terminals featuring only one of the two available CPs but with both frequency slots. However, there are many different applicable combinations of various users sharing the resources via the “matrixes”. For instance, the symmetric 2-to-2 matrix is applicable for a user terminal featuring both two CPs with doubled channel capacity. Similarly the symmetric 4-to-4 matrix is also applicable to a user terminal featuring both two CPs and two frequency slots for quadrupled channel capacity. These two matrixes are functional mechanisms for wavefront multiplexing and de-multiplexing.
FIG. 5B depicts the two mathematic matrix equations converting CP signals into LP channels as they are captured by a LP hub. The differential propagation effects are not included. The one on the left represents the conversions of two CP signals, s1 in RHCP and s2 in LHCP, into two aggregated LP signals in an HP and a VP channel. The one on the right is a 4-to-4 mathematic matrix equation representing signal conversions in four LP channels; two in HP and two in VP at two common frequency slots. The symmetric matrix is constructed under the constraints that can support user terminals featuring only one of the two available CPs but with both frequency slots.
FIG. 5C illustrates a simplified block diagram of a LP hub accessed by four CP terminals for independent data stream relay back to the hub station utilizing the same matrix conversion assumptions in FIG. 5B . It also displays return-links from the four users to a hub. The architecture is constructed under the constraints that support user terminals featuring only one of the two available CPs but with both frequency slots.
FIG. 5D depicts a simplified block diagram for implementation of technique as shown in FIG. 5C . The WF muxing are for CP to LP conversions. Standard low-noise amplifiers (LNAs) and high power amplifiers (HPAs) are not shown. Diagnostic signals (pilots) are embedded for phase and amplitude differential equalization among multiple paths for orthogonal WF reconstructions. WF demuxing is used to separate the signals from two portable devices.
FIG. 6 illustrates a simplified block diagram for implementation of technique as shown in FIG. 5D , for scenarios with multiple LP channels in two hubs at a common frequency slot, instead of multiple LP channels in two common frequency slots in a hub. Standard low-noise amplifiers (LNAs) and high power amplifiers (HPAs) are not shown. Diagnostic signals (pilots) are imbedded to equalize phase and amplitude differentials among multiple paths for orthogonal WF reconstructions.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 100 illustrates particular embodiments of our proposed techniques, assuming that portable CP terminals are within a common field-of-view of both hubs. The terminals are return-links (RL) examples depicting communications from 2 portable devices to a hub.
Panel (a) 110 illustrates a conventional technique for accessing a CP communications hub asset 112 via CP terminals 111 a and 111 b . Terminals 111 a and 2 111 b relay independent data streams s1(t) and s2(t) to CP hub 112 . Terminal 1 111 a in right-hand circularly-polarized (RHCP) waveforms is allocated for RHCP channel 112 a at frequency slot “fo” on the CP hub. Similarly, terminal 2 111 b in left-hand circularly-polarized (LHCP) waveforms is allocated for second CP channel 112 b at the same frequency slot “fo” but in LHCP on the hub. As a result, s1(t) goes through a RHCP active channel while s2(t) is independently conditioned by another active channel in LHCP. The “active channel” performs low-noise amplifications, proper filtering processing, frequency translations, etc. Hub receiving processor 113 will receive both s1(t) and s2(t) independently through two separated antenna ports: s1(t) from a RHCP and s2(t) a LHCP port.
Panel (b) 120 depicts an operational scenario where CP terminals 111 relay data through LP hub 122 . Specifically, active LP channels 122 a and 122 b are used in the LP hub. 1 HP and 1 VP channels are on a common frequency slot.
Mathematically, we select a set of 2-dimensional orthogonal Wave-Front (WF) vectors, [1, i] and [1, −i], to match the signal structures of polarizers for RHCP and LHCP signals. The 2-to-2 WF muxers and demuxers are implemented by analog polarizers in RF instead of 2-to-2 FFT digital processors, such that
S 1( t )=[ v+h i]s 1( t ) (1a)
S 2( t )=[ v−h i]s 2( t ) (1b)
S1 is radiated by terminal 1 111 a in RHCP while S2 by terminal 2 111 b is in LHCP format. Equivalently, S1 in RHCP is transmitted in both HP and VP with a fixed phase distribution, in that the phase in HP is always 90° ahead of that in VP.
As the S1 signals in RHCP arrive at selected LP hub 122 , both VP and HP components will be picked up “concurrently” by two LP channels at a common frequency slot. As depicted, one is in VP 122 a and the other in HP 122 b active channel.
Similarly S2 is also concurrently transmitted in both HP and VP with a fixed phase distribution, in that the phase in HP is always 90° behind that in VP. As the S2 signals in LHCP arrive at selected LP hub 122 , both VP and HP components will be picked up “concurrently” by two LP active channels. As depicted, one in VP 122 a and the other in HP 122 b.
Each LP channel is occupied by an aggregated signal stream consisting of two concurrent, independent signals s1 and s2. A caveat is that s1 and s2 cannot be seperated from the associated aggregatted signal stream as they are not multiplexed by code, time, or frequency. Rather, there are special relationships, also called “wavefronts” (WFs) between the two s1 signals in both LP channels, with something similar for s2 signals. s1 and s2 can be separated and recovered with both aggregated signals from the LP channels are processed simultaneously. The two signals are therefore multiplexed spatially while propagating through both paths.
The conditioned signals by VP channel 112 a and HP channel 122 b are designated as Yh (t) and Yv(t) respectively. The amplitude attentuations and phased delays due to propagation and electronics for the HP and VP paths are identified as (Ah and Av) and (α and β) respectively, where
Yv ( t )= s 1( t )+ s 2( t ) (1a)
Yh ( t )= i[s 1( t )− s 2( t )] (1b)
As the signals arrive at a LP hub 112 , polarization alignment processor 124 and a RF polarizer from a Rx CP antenna will serve as the WF demuxer functions, where the two concurrent CP antenna outputs will be:
Z rhcp ( t )=[ Av exp( j α)* Yv ( t )− i Ah exp( j β)* Yh ( t )]/2 (2a)
Z lhcp ( t )=[ Av exp( j α)* Yv ( t )+ i Ah exp( j β) Yh ( t )]/2 (2b)
Furthermore, in terms of s1 and s2 Equation (1) can be re-written as
Z
rhcp
(
t
)
=
[
Av
exp
(
jα
)
*
(
s
1
+
s
2
)
-
ⅈ
Ah
exp
(
jβ
)
*
(
ⅈ
s
1
-
ⅈ
s
2
)
]
/
2
=
s
1
[
Av
exp
(
jα
)
+
Ah
exp
(
j
β
)
]
/
2
+
s
2
[
Av
exp
(
jα
)
-
Ah
exp
(
jβ
)
]
/
2
,
(
3
a
)
Z
lhcp
(
t
)
=
[
Av
exp
(
jα
)
*
(
s
1
+
s
2
)
Yv
(
t
)
+
ⅈ
Ah
exp
(
jβ
)
(
ⅈ
s
1
-
ⅈ
s
2
)
]
/
2
=
s
1
[
Av
exp
(
jα
)
-
Ah
exp
(
j
β
)
]
/
2
+
s
2
[
Av
exp
(
jα
)
+
Ah
exp
(
jβ
)
]
/
2.
(
3
b
)
In general, the two wavefronts will not be orthogonal when they arrive at polarization alignment processor 124 . Diagnostic and compensation circuits (not shown) are present for amplitude and phase differential adjustment among the HP and VP paths. As the amplitude and phase effects of the two paths are equalized, the WFs regain orthogonality, wherein the associated signals can then be precisely reconstituted.
For hub operators, the LP hub assets (RF power and frequency bandwidth) from channels 122 a and 122 b are grouped together and shared by two seperated users via unique orthogonal waveforms which happen to be conventional RHCP and LHCP. Each LP channel “serves” only one of the aggregated wavefront components (wfc). It always takes two components to reconstruct relayed signals
It should be noted that the linear channels need not be from the same hub. There may be situations that call for LP hubs to cover the same service areas.
FIG. 2A 200 a depicts a receiving beam-forming block diagram for portable device 210 with receiving/radiating elements 211 distributed as depicted. Signals received by elements 211 are conditioned (amplified, and filtered) by LNAs (low noise amplifiers) 222 , frequency down-converted by down converters 223 , then digitized by A/Ds (analog-to-digital converters) 224 before processing via digital beam forming (DBF) networks 225 . DBF processors 225 dynamically generate two CP beams, one in RHCP and one in LHCP. DBF 225 performs weighted summations of all received signals captured by N individual elements, where N is an integer and N>2. Complex weightings are then performed by N complex digital multipliers 2251 , with the summing via digital combiners 2252 . The multiplicands are the N captured received signals and the multipliers are beam weight vectors (BWV), of which the components feature complex parameters dynamically controlled by controller 226 based on the knowledge of the device current positions and orientation with respect to the designated hubs locations and orientations. The data is gained from embedded inertial reference devices such as MEM IMU 227 , and other stored information 228 such as array geometries of the remote device, the directions of intended hubs, etc. The controller will “calculate” or “derive” the proper BWV such that the composite receiving patterns from distributed array 211 will feature adequate antenna gains and excellent polarization orientations toward the intended base-stations or communications hubs.
Additional circuits (not shown) may be added to enhance the polarization isolations between the RHCP and LHCP channels. The additional diagnostic circuits may be based on correlations between RHCP and LHCP assuming these are completely independent and therefore completely uncorrelated. An optimization loop may be incorporated as one of the drivers for altering the two sets of BWVs. The optimization goals are to minimize the cross-correlations between RHCP and LHCP channels.
FIG. 2B 200 b depicts a transmitting beam-forming block diagram for portable device 210 , with receiving/radiating elements 211 distributed as depicted. The transmitting signals are sent to transmitting digital beam forming (DBF) networks 235 , dynamically generating two CP beams for the N-element distributed arrays, one in RHCP and the other LHCP, where N is an integer and N>2. DBF functions 235 for a CP beam perform signal replications by first re-generating N-identical components, and then weight replicating streams individually by N components of a BWV. The weighted N signals from the RHCP DBF and those from the LHCP DBF for individual radiating elements are summed together before conversion to analogue format by D/As 234 , frequency up-converted by up-converters 233 and power amplified by power-amplifiers 232 before being radiated individually to free space by distributed array elements 211 . The complex weightings are performed by N complex digital multipliers 2351 and the duplications are via digital replicators 2352 . The multiplicands are the N captured received signals and the multipliers are the beam weight vectors (BWV). The components featuring complex parameters that are dynamically controlled by controller 226 are based on the knowledge of the device's current positions and orientations with respect to the designated hubs locations and orientations. This knowledge is derived from embedded inertial reference devices 227 , and other stored information 228 such as array geometries of the remote device, and the directions of intended hubs. The controller will “calculate” and/or “derive” the proper BWV such that the composite receiving patterns from the distributed array 211 will feature adequate antenna gains and excellent polarization orientations toward the intended base-stations or communications hubs.
FIG. 3 300 depicts the same scenario as that in FIG. 1 , except it is for “forward links” communications flows from a LP hub 312 to CP remotes 311 . A preprocessing unit 324 in the hub is used to “pre-compensate” for the amplitude and phase differentials among the two LP propagation paths. Signals in the corresponding forward-link channels for terminal-1 311 a and terminal-2 311 b are available locally at the source location 312 . These signals can be used as feedback for the pre-compensation processing 324 .
FIG. 4 400 depicts the similar scenario as that in FIG. 3 in that both are for “forward links” communications flows. FIG. 4 400 depicts flow from LP hub 412 to CP remotes 411 . LP hub 412 must feature both HP and VP polarization transmission functions. The desired signals to the first remote terminal s1(t) is decomposed into two sub streams s1a(t) and s1b(t). The decomposition process may be a 2-to-2 FFT or a 1-to-2 TDM demuxing switch. Pre-processor 424 performs two linear combinations, combining s1a (the first signals stream for terminal-1 411 a ), and s1b (the second signals stream also for terminal-1 411 a ). The weightings among the two linear combinations are for generating two equivalent CP signals at anticipated destinations 411 , and shall include effects from propagations and unbalanced electronics. Signals in both forward-link channels for terminal-1 are available locally at the source location 412 . These signals will be used as feedback to optimize the pre-compensation processing 424 . At the destination, the first remote terminal 411 a will re-combine the two received substreams s1a(t) and s1b(t) into the reconstituted signal stream s1(t).
FIG. 5A depicts wavefront multiplexing matrixes 512 and 522 for CP user terminals to access multiple communications channels in LP hubs. 2-by-2 matrix 512 is for conversion of two independent CP signals (one at RHCP 512 a and the other at LHCP 512 b ) into two signal streams in LP (one in HP and the other in VP). All the signal streams (two inputs and two outputs) are at same frequency slot f1.
Similarly, 4-by-4 matrix 522 on the right converts 4 independent CP signals (two at RHCP 522 a and 522 c and the other two at LHCP 522 b and 522 d ). As a result, an input stream is replicated in every output stream, and each output stream consists of all input streams.
FIG. 5B depicts the mathematic matrix equations 510 and 520 for conversion of CP signals into LP channels as they are captured by an LP satellite. The differential propagation effects are not included. 2-by-2 matrix equation 510 represents the conversions of two CP signals 513 , s1 in RHCP and s2 in LHCP, into two aggregated LP signals 511 in an HP and a VP channels in a LP hub. The symmetrical conversion matrix 512 is the WF muxing processor and is referred as Mf2.
Mf 2 _ = [ 1 i i 1 ] ( 4 a )
It should be noted that Mf2 can be used to convert two CP signals into two LP signals, and can also convert two LP signals into two CP signals. Furthermore,
½ ·Mf 2 ·Mf 2* T =I (4b)
Mf2 can be used as a WF muxer and its corresponding WF demuxer will be Mf2* T . The two resulting wavefronts (WFs) 512 a and 512 b as depicted in FIG. 5A are orthogonal to each other.
Matrix equation 520 is a 4-by-4 mathematic matrix equation representing signal conversions from 4 CP signals 523 in four LP channels 521 of a communications hub, where two in HP and two in VP are at two identical frequency slots. Symmetric matrix 522 is constructed under the constraints that all the user terminals feature only one of the two available CPs but with both frequency slots.
The symmetrical conversion matrix 522 is the WF muxing processor and is referred as Mf4.
Mf 4 _ = [ 1 i 1 i i 1 i 1 1 i - 1 - i i 1 - i - 1 ] ( 5 a )
It should be noted that Mf4 can be used to convert four CP signals into four LP signals, and it can also convert four LP signals into four CP signals. Furthermore,
¼ ·Mf 4· Mf 4* T =I (5b)
Mf4 can be used as a WF muxer and its corresponding WF demuxer will be Mf4* T . The four resulting wavefronts (WFs) 522 a , 522 b , 522 c , and 522 d as depicted in FIG. 5A are orthogonal to each other.
In FIG. 5C 530 , we have split the two CP pairs for two common frequency slots; 1 pair of CP at fa and the other pair at fb. Similarly, the two LP pairs are for the same two common frequency slots; 1 pair of LP at fa and the other pair at fb.
S1 is a waveform occupying two RHCP channels, one at fa and the other at fb, carrying signal s1 radiated by terminal-1 531 a.
S2 is a waveform occupying two LHCP channels, one at fa and the other at fb, carrying signal s2 radiated by terminal-2 531 b
S3 is a waveform occupying two RHCP channels, one at fa and the other at fb, carrying signal s3 radiated by terminal-3 531 c.
S4 is a waveform occupying two LHCP channels, one at fa and the other at fb, carrying signal s4 radiated by terminal-4 531 d
When these signals arrive at a LP satellite 532 , the 4 LP channels will feature the following aggregated signals:
VP channel at fa 532 va : s1+is2+s3+is4
HP channel at fa 532 ha : is1+s2+is3+s4
VP channel at fb 532 vb : s1+i s2−s3−is4
HP channel at fb 532 hb ; is1+s2−is3−s4
When these signals captured by LP hub 532 , the channels will feature the following aggregated signals, assuming the amplitude attenuations and phase delays among the 4 propagation channels are identical, where
RHCP channel at fa: y1(t)=is2+is4
LHCP channel at fa: y2(t)=s1+s3
RHCP channel at fb: y3(t)=is2−is4
LHCP channel at fb; y4(t)=s1−s3
A post processor, not shown, will calculate the s1, s2, s3, and s4 according to the received y1, y2, y3, and y4. In addition, the post processor performs amplitude and phase equalizations among the propagation paths.
The relative phases between the CP components at two frequencies are critical. When the relative geometries among user 531 and hub 532 are fixed, the cumulative phase difference among signals at two separated frequencies propagating from a source 531 to a destination 532 is constant; therefore, the accumulated phase difference is constant. However when a user 531 is drifting relative to hub 532 , the phase differences between two signals at two frequencies propagating from user source location 531 to hub 532 will vary accordingly. Additional phase differentials may result from Doppler effects.
At destination 532 , four concurrent receiving functions are present: RHCPa, RHCPb, LHCPa, and LHCPb. The associated phase and amplitude differential effects among the 4 propagation channels at different frequencies and polarizations must be continuously calibrated and equalized to assure orthogonality among multiple WFs when they arrive at destination 532 .
FIG. 5D 540 illustrates a simplified block diagram for an implementation technique for FIG. 5C . Standard low-noise amplifiers (LNAs) and high power amplifiers (HPAs) are not presently shown. 540 depicts top level implementation concepts for the hub 532 as well as two 531 a and 531 b of the four users 531 . Terminal 541 - t 1 for user 531 a features transmissions of an identical signal stream s1 via two RHCP channels at fa and fb simultaneously. Embedded pilots for diagnostics are multiplexed 541 - 1 with a transmission stream x1(t). The mux processing may be a standard technique such as TDM, FDM, or CDM for minimizing bandwidth assets dedicated to probe signals. This in turn supports optimization loop 543 - 5 at the destination. The muxed signals are frequency up-converted 541 - 2 to two predetermined frequency slots before joining by a FDM output mux 541 - 3 . The muxed signals are amplified and radiated by antenna 541 - 0 to designated hub 542 .
Similarly, terminal 541 - t 2 for user 531 b features transmissions of another identical signal stream s2 via two LHCP channels at fa and fb simultaneously. Embedded pilot signals for diagnostic purposes are multiplexed 541 - 1 with a transmission stream x1(t). The mux processing may be a standard technique such as TDM, FDM, or CDM minimizing bandwidth assets dedicated to probe signals. This in turn supports optimization loop 543 - 5 at the destination. The muxed signals are frequency up-converted 541 - 2 to two predetermined frequency slots before joining by a FDM output mux 541 - 3 . The muxed signals are amplified and radiated by antenna 541 - 0 to designated communications hub 542 .
Hub 542 provides two pairs of LP communications channels: the inputs for the first ones 542 - ha and 542 - va are at fa, and those for the other set 542 - hb and 542 - vb are at fb. The corresponding output frequencies are at fa′ and fb′, respectively.
At destination 543 , antenna 543 - 0 features independent RHCP and LHCP ports. The received RHCP signals Y1(t) and LHCP signals Y2(t) are conditioned (amplified and filtered), FDM de-muxed 543 - 1 and frequency down converted 543 - 2 , then fed into electronic filters 543 - 3 a as equalization mechanisms before WF demuxing processor 543 - 3 b . The WF demuxer 543 - 3 b features 4 output ports dedicated for users 531 .
The corresponding outputs are de-muxed 543 - 4 separating desired signals x1(t), x2(t) from probe signals. The recovered probing signals are used by the optimization loop 543 - 5 as diagnostic signals to equalize phase and amplitude differentials among multiple paths for orthogonal WF reconstructions.
FIG. 6 600 illustrates a simplified block diagram of an implementation technique similar to for FIG. 5D , specifically for scenarios that utilize multiple LP channels in two satellites 642 at a common frequency slot. Standard low-noise amplifiers (LNAs) and high power amplifiers (HPAs) are not shown. Diagnostic signals (pilots) are imbedded to equalize phase and amplitude differentials among multiple paths for orthogonal WF reconstructions.
Terminal 641 - t 1 for a user 531 a features transmissions of an identical signal stream s1 via two RHCP channels at fa via two communications hubs concurrently covering a common service area. Embedded pilots for diagnostics are multiplexed 641 - 1 with a transmission stream x1(t). The mux processing may be a standard technique such as TDM, FDM, or CDM minimizing bandwidth assets dedicated to probe signals. this in turn supports optimization loop 643 - 5 at the destination. The muxed signals are frequency up-converted 641 - 2 to a predetermined frequency slot, amplified, power split into two signal paths, then individually radiated by antenna 641 - 0 to two designated satellites 642 .
Similarly, terminal 641 - t 2 for a user 531 b features transmissions of another identical signal stream s2 via two LHCP channels at fa via two communications hubs simultaneously. Embedded pilots for diagnostics are multiplexed 641 - 1 with a transmission stream x2(t). The mux processing may be a standard technique such as TDM, FDM, or CDM minimizing bandwidth assets dedicated to probe signals which support the optimization loop 643 - 5 at the destination. The muxed signals are frequency up-converted 641 - 2 to a predetermined frequency slot, amplified, divided into two paths and then radiated by a multi-beam antenna 641 - 0 to the two designated satellite 642 .
Selected communications hubs 642 provide two pairs of LP channels: the inputs for channels 642 - ha and 642 - va are at hub-1, inputs for channels 642 - hb and 642 - vb are at the second hub. The corresponding output frequencies are at fa′ and fb′, respectively.
At destination 643 , multi-beam antenna 643 - 0 features independent RHCP and LHCP ports aiming at both hubs. The two received RHCP signals Y1(t), Y3(t) and two Rx LHCP signals Y2(t) and Y4(t) are conditioned (amplified and filtered) and frequency down-converted 643 - 2 , then fed into electronic filters 643 - 3 a as equalization mechanisms before the WF demuxing processor 643 - 3 b . The WF demuxer 643 - 3 b features 4 output ports dedicated for users 531 .
The corresponding outputs are de-muxed 643 - 4 , separating desired signals x1(t), x2(t) and two sets of probe signals. The recovered probing signals are used by the optimization loop 543 - 5 as diagnostic signals to equalize phase and amplitude differentials among multiple paths for orthogonal WF reconstructions. | A novel terrestrial wireless communications technique for terrestrial portable terminals including hand-held mobile devices and fixed wireless instruments, utilizing a spoke-and-hub communications system, having a plurality of individual hubs and/or base-stations all in communications with the portable terminals. The portable terminals and the hubs are assigned to use incompatible polarity formats in terms of circularly polarity (CP) and linearly polarity (LP). In forward links, a signal processed by the LP ground telecommunications hubs is radiated through multiple antennas with various LP polarities to an individual CP user simultaneously. The multiple paths are organized via assignments of a plurality of polarities, frequency slots, and directions by wavefront multiplexing/demultiplexing techniques such that the same communications assets including frequency spectrum may be re-used by other users. The same polarity diversity methods can be extended to peer-to-peer communications. | 7 |
TECHNICAL FIELD
The present invention relates generally to hybrid powertrains for motorized vehicles, and hydraulic control thereof.
BACKGROUND OF THE INVENTION
Motorized vehicles include a powertrain operable to propel the vehicle and power the onboard vehicle electronics. The powertrain, or drivetrain, generally includes an engine that powers the final drive system through a multi-speed power transmission. Many vehicles are powered by a reciprocating-piston type internal combustion engine (ICE) because of its ready availability, relatively-inexpensive cost, light weight, and relative efficiency. Such engines include four-stroke compression-ignited diesel engines and four-stroke spark-ignited gasoline engines.
Hybrid vehicles utilize alternative power sources to propel the vehicle, minimizing reliance on the engine for power, and increasing overall fuel economy. A hybrid electric vehicle (HEV), for example, incorporates both electric energy and chemical energy, and converts the same into mechanical power to propel the vehicle and power the vehicle systems. The HEV generally employs one or more electric machines that operate individually or in concert with an internal combustion engine to propel the vehicle. Since hybrid vehicles can derive their power from sources other than the engine, engines in hybrid vehicles may be turned off while the vehicle is stopped or is being propelled by the alternative power source(s).
Series hybrid architectures, sometimes referred to as Range-Extended Electric Vehicles (REEVs), are generally characterized by an internal combustion engine in driving communication with an electric generator. The electric generator provides power to one or more electric motors operable to rotate the final drive members. There may be no direct mechanical connection between the engine and the drive members in a series hybrid powertrain. The lack of a mechanical link between the engine and wheels allows the engine to run at a constant and efficient rate, even as vehicle speed changes. The electric generator may also operate to start the internal combustion engine. The system may also allow the electric motor(s) to recover energy by slowing the vehicle and storing it in the battery through regenerative braking.
Parallel hybrid architectures are generally characterized by an internal combustion engine and one or more electric motor/generator assemblies, all of which have a direct mechanical coupling to the transmission. Parallel hybrid designs utilize combined electric motor/generators, which provide traction and may replace both the conventional starter motor and alternator. The motor/generators are electrically connected to an energy storage device (ESD). The energy storage device may be a chemical battery. A control unit is employed for regulating the electrical power interchange between the energy storage device and motor/generators, as well as the electrical power interchange between the first and second motor/generators.
Electrically-variable transmissions (EVT) provide for continuously variable speed ratios by combining features from both series and parallel hybrid powertrain architectures, and also elements of traditional, non-hybrid transmissions. EVTs may be designed to operate in both fixed-gear (FG) modes and EVT modes. When operating in a fixed-gear mode, the rotational speed of the transmission output member is a fixed ratio of the rotational speed of the input member from the engine, depending upon the selected arrangement of the differential gearing subsets. EVTs are also configured for engine operation that is mechanically independent from the final drive, thereby enabling high-torque continuously-variable speed ratios, electrically dominated launches, regenerative braking, engine-off idling, and two-mode operation.
An EVT may combine the motor/generators with differential gearing to achieve continuously variable torque and speed ratios between the input and output. The EVT can utilize the differential gearing to send a fraction of its transmitted power through the electric motor/generator(s) and the remainder of its power through another, parallel path that is mechanical. One form of differential gearing used is the epicyclic planetary gear arrangement. However, it is possible to design a power split transmission without planetary gears, for example, as by using bevel gears or other differential gearing.
Hydraulically-actuated torque-transmitting mechanisms, such as clutches and brakes, are selectively engageable to selectively activate the gear elements for establishing different forward and reverse speed ratios and modes between the transmission input and output shafts. The term “clutch” is used hereinafter to refer generally to torque transmitting mechanisms, including, without limitation, devices commonly referred to as clutches and brakes. Shifting from one speed ratio or mode to another may be in response to vehicle conditions and operator (driver) demands. The “speed ratio” is generally defined as the transmission input speed divided by the transmission output speed. Thus, a low gear range has a high speed ratio, and a high gear range has a relatively lower speed ratio. Because EVTs are not limited to single-speed gear ratios, the different operating states may be referred to as ranges or modes.
The range or mode change may be controlled through a multi-clutch synchronization and release process. A first clutch associated with a currently-active range is carrying torque in an applied state, while a second clutch associated with a currently-inactive second range is carrying no torque in a released state. Shifting from a first range to a second range is accomplished by controlling the second, unapplied clutch to zero slip speed, and applying the second clutch (the oncoming clutch) thereby placing the EVT in a state with both clutches applied. The second range is then entered by the release of the first clutch (the offgoing clutch).
SUMMARY OF THE DISCLOSURE
A method of hydraulic pressure control for a hybrid transmission is provided. The hybrid transmission has a main pump deriving power from an internal combustion engine and in selective fluid flow communication with a hydraulic circuit of the hybrid transmission through a main regulator. The hybrid transmission also has an auxiliary pump not deriving power from the internal combustion engine and in selective fluid flow communication with the hydraulic circuit through an auxiliary regulator.
The method includes commanding the internal combustion engine to begin transition to an engine-off state, and commanding the main pump to begin a transition to a non-operating state. A pressure control solenoid (PCS) is moved from a low position to a high position. The PCS is operatively in communication with both the main regulator and the auxiliary regulator, such that the main regulator moves from a low pressure setting to a high pressure setting and the auxiliary regulator moves from a low pressure setting to a high pressure setting.
The method includes commanding the auxiliary pump to begin a transition to an auxiliary-on state. The method further includes operating the PCS in the high position during the transition of the main pump to the non-operating state. The transition of the auxiliary pump to the auxiliary-on state is finished before finishing the transition of the main pump to the non-operating state.
The high pressure setting of the main regulator may be greater than the high pressure setting of the auxiliary regulator. The method may further include placing the main regulator in fluid flow communication with the hydraulic circuit; transitioning fluid flow communication with the hydraulic circuit from the main regulator to the auxiliary regulator; and ending fluid flow communication from the main regulator to the hydraulic circuit before completing the transition of the main pump to the non-operating state.
Additionally, the method may include commanding the internal combustion engine to begin a transition to an engine-on state, and commanding the main pump to begin a transition to an operating state. The auxiliary pump is then commanded to begin a transition to an auxiliary-off state, and the PCS is operated in the high position during the transition of the main pump to the operating state. The transition of the main pump to the operating state is completed before finishing the transition of the auxiliary pump to the auxiliary-off state. The PCS is moved from the high position to the low position, such that the main regulator moves from the high pressure setting to the low pressure setting and the auxiliary regulator moves from the high pressure setting to the low pressure setting. The method may further include transitioning fluid flow communication with the hydraulic circuit from the auxiliary regulator to the main regulator, and ending fluid flow communication from the auxiliary regulator to the hydraulic circuit before completing the transition of the auxiliary pump to the auxiliary-off state.
The above features and advantages, and other features and advantages of the present invention will be readily apparent from the following detailed description of the preferred embodiments and other modes for carrying out the present invention when taken in connection with the accompanying drawings and appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic lever diagram illustration of an exemplary vehicle powertrain with a multi-mode, electrically-variable hybrid transmission in accordance with the present invention;
FIG. 2 is a truth table listing the engaged torque-transmitting mechanisms for each of the operating modes of the transmission illustrated in FIG. 1 ;
FIG. 3 is a graphical representation of various regions of operation with respect to input and output speeds of the transmission illustrated in FIG. 1 ;
FIG. 4 is a schematic illustration of an exemplary pressure control system for feeding transmission fluid to the hydraulic circuit of the transmission illustrated in FIG. 1 , shown while the auxiliary pump is supplying the hydraulic circuit;
FIG. 5 is an exemplary graphical representation of main and auxiliary regulator pressure as a function of pressure control solenoid (PCS) pressure;
FIG. 6A is a graphical representation of an exemplary control process for a transition from the main to the auxiliary pump of FIG. 4 ; and
FIG. 6B is a graphical representation of an exemplary control process for a transition from the auxiliary to the main pump of FIG. 4 .
DESCRIPTION OF PREFERRED EMBODIMENTS
The claimed invention is described herein in the context of a hybrid-type vehicular powertrain having a multi-mode, multi-speed, electrically-variable, hybrid transmission, which is intended solely to offer a representative application by which the present invention may be incorporated and practiced. The claimed invention is not limited to the particular powertrain arrangement shown in the drawings. Furthermore, the hybrid powertrain illustrated herein has been greatly simplified, it being understood that further information regarding the standard operation of a hybrid powertrain, or a hybrid-type vehicle will be recognized by those having ordinary skill in the art.
Referring to the drawings, wherein like reference numbers refer to like components throughout the several views, there is shown in FIG. 1 a lever diagram depiction of an exemplary vehicle powertrain system, designated generally as 10 . The powertrain 10 includes a restartable engine 12 that is selectively drivingly connected to, or in power flow communication with, a final drive system 16 via a multi-mode, electrically-variable hybrid-type power transmission 14 .
A lever diagram is a schematic representation of the components of a mechanical device such as an automatic transmission. Each individual lever represents a planetary gearset, wherein the three basic mechanical components of the planetary gear are each represented by a node. Therefore, a single lever contains three nodes: one for the sun gear member, one for the planet gear carrier member, and one for the ring gear member. The relative length between the nodes of each lever may be used to represent the ring-to-sun ratio of each respective gearset. These lever ratios, in turn, are used to vary the gear ratios of the transmission in order to achieve appropriate ratios and ratio progression. Mechanical couplings or interconnections between the nodes of the various planetary gear sets and other components of the transmission (such as motor/generators) are illustrated by thin, horizontal lines. Torque transmitting devices such as clutches and brakes are presented as interleaved fingers. If the device is a brake, one set of the fingers is grounded.
The transmission 14 is designed to receive at least a portion of its driving power from the engine 12 , through an input member 18 , for example. The transmission input member 18 , which is in the nature of a shaft, may be the engine output shaft (also referred to as a “crankshaft”). Alternatively, a transient torque damper (not shown) may be implemented between the engine 12 and the input member 18 of the transmission 14 . The engine 12 transfers power to the transmission 14 , which distributes torque through a transmission output member or shaft 20 to drive the final drive system 16 , and thereby propel the vehicle (not shown).
In the embodiment depicted in FIG. 1 , the engine 12 may be any of numerous forms of petroleum-fueled prime movers, such as the reciprocating-piston type internal combustion engines, which includes spark-ignited gasoline engines and compression-ignited diesel engines. The engine 12 is readily adaptable to provide its available power to the transmission 14 at a range of operating speeds, for example, from idle, at or near 600 revolutions per minute (RPM), to over 6,000 RPM. Irrespective of the means by which the engine 12 is connected to the transmission 14 , the input member 18 is connected to a differential gear set encased within the transmission 14 , as explained in more detail herein.
Referring still to FIG. 1 , the hybrid transmission 14 utilizes one or more differential gear arrangements, preferably in the nature of three interconnected epicyclic planetary gear sets, designated generally at 24 , 26 and 28 , respectively. Each gear set includes three gear members: a first, second and third member. In referring to the first, second and third gear sets in this description and in the claims, these sets may be counted “first” to “third” in any order in the drawings (e.g., left to right, right to left, etc.). Likewise, in referring to the first, second and third members of each gear set in this description and in the claims, these members may be counted or identified as “first” to “third” in any order in the drawings (e.g., top to bottom, bottom to top, etc.) for each gear set.
The first planetary gear set 24 has three gear members: a first, second and third member 30 , 32 and 34 ; respectively. In a preferred embodiment, the first member 30 includes of an outer gear member (which may be referred to as a “ring gear”) that circumscribes the third member 34 , which may include of an inner gear member (which may be referred to as a “sun gear”). In this instance, the second member 32 acts as a planet carrier member. That is, a plurality of planetary gear members (which may be referred to as “pinion gears”) are rotatably mounted on the second member, planet carrier 32 . Each planetary gear member is meshingly engaged with both the first member, ring gear 30 and the third member, sun gear 34 .
The second planetary gear set 26 also has three gear members: a first, second and third member 40 , 42 and 44 , respectively. In the preferred embodiment discussed above with respect to the first planetary gear set 24 , the first member 40 of the second planetary gear set 26 is an outer “ring” gear member that circumscribes the third member 44 , which is an inner “sun” gear member. The ring gear member 40 is coaxially aligned and rotatable with respect to the sun gear member 44 . A plurality of planetary gear members are rotatably mounted on the second member 42 , which acts as a planet carrier member, such that each planetary gear meshingly engages both the ring gear member 40 and the sun gear member 44 .
The third planetary gear set 28 , similar to the first and second gear sets 24 , 26 , also has first, second and third members 50 , 52 and 54 , respectively. In this arrangement, the first member 50 is preferably the outer “ring” gear, which circumscribes the third member 54 or inner “sun” gear. The second member 52 is the planet carrier in this particular gear set, and is coaxially aligned and rotatable with respect to the sun gear member 54 . As such, a plurality of planetary or pinion gear members are rotatably mounted on the carrier member 52 . Each of the pinion gear members is aligned to meshingly engage either the ring gear member 50 and an adjacent pinion gear member or the sun gear member 54 and an adjacent pinion gear member.
In one embodiment on the transmission 14 , the first and second planetary gear sets 24 , 26 each include simple planetary gear sets, whereas the third planetary gear set includes a compound planetary gear set. However, each of the carrier members described above can be either a single-pinion (simple) carrier assembly or a double-pinion (compound) carrier assembly. Embodiments with long pinions are also possible.
The first, second and third planetary gear sets 24 , 26 , 28 are compounded in that the second member 32 of the first planetary gear set 24 is conjoined with (i.e., continuously connected to) the second member 42 of the second planetary gear set 26 and the third member 54 of the third planetary gear set 28 , as by a central shaft 36 . As such, these three gear members 32 , 42 , 54 are rigidly attached for common rotation.
The engine 12 is continuously connected to the first member 30 of first planetary gear set 24 through an integral hub plate 38 , for example, for common rotation therewith. The third member 34 of the first planetary gear set 24 is continuously connected, for example, by a first sleeve shaft 46 , to a first motor/generator assembly 56 , interchangeably referred to herein as “motor A”. The third member 44 of the second planetary gear set 26 is continuously connected by a second sleeve shaft 48 , to a second motor/generator assembly 58 , also interchangeably referred to herein as “motor B”. The first member 50 of the third planetary gear set 28 is continuously connected to transmission output member 20 through an integral hub plate, for example. The first and second sleeve shafts 46 , 48 may circumscribe the central shaft 36 .
A first torque transfer device 70 —which is herein interchangeably referred to as clutch “C 1 ”—selectively connects the second gear member 52 with a stationary member, represented in FIG. 1 by transmission housing 60 . The second sleeve shaft 48 , and thus gear member 44 and motor/generator 58 , is selectively connectable to the second member 52 of the third planetary gear set 28 through the selective engagement of a second torque transfer device 72 —which is herein interchangeably referred to as clutch “C 2 ”. A third torque transfer device 74 —which is herein interchangeably referred to as clutch “C 3 ”—selectively connects the first gear member 40 of the second planetary gear set 26 to the transmission housing 60 . The first sleeve shaft 46 , and thus third gear member 34 and first motor/generator 56 , is also selectively connectable to the first member 40 of the second planetary gear set 26 , through the selective engagement of a fourth torque transfer device 76 —which is herein interchangeably referred to as clutch “C 4 ”.
A fifth torque transfer device 78 —which is herein interchangeably referred to as clutch “C 5 ”—selectively connects the input member 18 of engine 12 and the first gear member 30 of the first planetary gear set 24 to the transmission housing 60 . Clutch C 5 is an input brake clutch, which selectively locks the input member 18 when engine 12 is off. Locking input member 18 provides more reaction for regenerative braking energy. As shown below, in reference to FIG. 2 , C 5 is not involved in the mode/gear/neutral shifting maneuvers of transmission 14 .
The first and second torque transfer devices 70 , 72 (C 1 and C 2 ) may be referred to as “output clutches.” The third and fourth torque transfer devices 74 , 76 (C 3 and C 4 ) may be referred to as “holding clutches”.
In the exemplary embodiment depicted in FIG. 1 , the various torque transfer devices 70 , 72 , 74 , 76 , 78 (C 1 -C 5 ) are all friction clutches. However, other conventional clutch configurations may be employed, such as dog clutches, rocker clutches, and others recognizable to those having ordinary skill in the art. The clutches C 1 -C 5 may be hydraulically actuated, receiving pressurized hydraulic fluid from a pump (not shown). Hydraulic actuation of clutches C 1 -C 5 is accomplished, for example, by using a hydraulic fluid control circuit.
In the exemplary embodiment described herein, wherein the hybrid powertrain 10 is used as a land vehicle, the transmission output shaft 20 is operatively connected to the final drive system (or “driveline”). The driveline may include a front or rear differential, or other torque transfer device, which provides torque output to one or more wheels through respective vehicular axles or half-shafts (not shown). The wheels may be either front or rear wheels of the vehicle on which they are employed, or they may be a drive gear of a track vehicle. Those having ordinary skill in the art will recognize that the final drive system may include any known configuration, including front wheel drive (FWD), rear wheel drive (RWD), four-wheel drive (4 WD), or all-wheel drive (AWD), without altering the scope of the claimed invention.
All of the planetary gear sets 24 , 26 , 28 , as well as the first and second motor/generators 56 , 58 (motor A and motor B,) are preferably coaxially oriented about the intermediate central shaft 36 or another axis. Motor A or motor B may take on an annular configuration, permitting one or both to generally circumscribe the three planetary gear sets 24 , 26 , 28 . Such a configuration may reduce the overall envelope, i.e., the diametrical and longitudinal dimensions, of the hybrid transmission 14 are minimized.
The hybrid transmission 14 receives input motive torque from a plurality of torque-generative devices. “Torque-generative devices” include the engine 12 and the motors/generators 56 , 58 as a result of energy conversion from fuel stored in a fuel tank or electrical potential stored in an electrical energy storage device (neither of which is shown).
The engine 12 , motor A ( 56 ,) and motor B ( 58 ) may operate individually or in concert—in conjunction with the planetary gear sets and selectively-engageable torque-transmitting mechanisms—to rotate the transmission output shaft 20 . Moreover, motor A and motor B are preferably configured to selectively operate as both a motor and a generator. For example, motor A and motor B are capable of converting electrical energy to mechanical energy (e.g., during vehicle propulsion), and further capable of converting mechanical energy to electrical energy (e.g., during regenerative braking or during periods of excess power supply from engine 12 ).
With continuing reference to FIG. 1 , an electronic control apparatus (or “controller”) having a distributed controller architecture is shown schematically in an exemplary embodiment as a microprocessor-based electronic control unit (ECU) 80 . The ECU 80 includes a storage medium with a suitable amount of programmable memory, collectively represented at 82 , that is programmed to include, without limitation, an algorithm or method 100 of regulating operation of a multi-mode hybrid transmission, as will be discussed in further detail below with respect to FIG. 4 .
The control apparatus is operable, as described hereinafter, to provide coordinated system control of the powertrain 10 schematically depicted and described herein. The constituent elements of the control apparatus may be a subset of an overall vehicle control system. The control system is operable to synthesize pertinent information and inputs, and execute control methods and algorithms to control various actuators to achieve control targets. The control system monitors target and parameters including, without limitation: fuel economy, emissions, performance, driveability, and protection of drivetrain hardware—such as, but not limited to, the engine 12 , transmission 14 , motor A, motor B, and final drive 16 .
The distributed controller architecture (ECU 80 ) may include a Transmission Control Module (TCM), an Engine Control Module (ECM), a Transmission Power Inverter Module (TPIM), and a Battery Pack Control Module (BPCM). A hybrid control module (HCP) may be integrated to offer overall control and coordination of the aforementioned controllers.
A User Interface (UI) is operatively connected to a plurality of devices (not shown) through which a vehicle operator typically controls or directs operation of the powertrain. Exemplary vehicle operator inputs to the UI include an accelerator pedal, a brake pedal, transmission gear selector, vehicle speed cruise control, and other inputs recognizable to those having ordinary skill in the art.
Each of the aforementioned controllers communicates with other controllers, sensors, actuators, etc., via a local area network (LAN) bus or communication architecture. The LAN bus allows for structured communication of control parameters and commands between the various controllers. The communication protocol utilized is application-specific. For example, and without limitation, one useable communication protocol is the Society of Automotive Engineers standard J1939. The LAN bus and appropriate protocols provide for robust messaging and multi-controller interfacing between the aforementioned controllers, and other controllers providing functionality such as antilock brakes, traction control, and vehicle stability.
The ECM is operatively connected to, and in communication with, the engine 12 . The ECM is configured to acquire data from a variety of sensors and control a variety of actuators of the engine 12 over a plurality of discrete lines. The ECM receives an engine torque command from the HCP, generates a desired axle torque, and an indication of actual engine torque, which is communicated to the HCP. Various other parameters that may be sensed by the ECM include engine coolant temperature, engine input speed to the transmission, manifold pressure, and ambient air temperature and pressure. Various actuators that may be controlled by the ECM include, without limitation, fuel injectors, ignition modules, and throttle control modules.
The TCM is operatively connected to the transmission 14 , and functions to acquire data from a variety of sensors and provide command signals to the transmission 14 . Inputs from the TCM to the HCP may include estimated clutch torques for each of the clutches C 1 -C 5 , and rotational speed of the transmission output shaft 20 . Additional actuators and sensors may be used to provide additional information from the TCM to the HCP for control purposes.
Each of the aforementioned controllers may be a general-purpose digital computer, generally including a microprocessor or central processing unit, read only memory (ROM), random access memory (RAM), electrically programmable read only memory (EPROM), high speed clock, analog to digital (A/D) and digital to analog (D/A) circuitry, and input/output circuitry and devices (I/O) and appropriate signal conditioning and buffer circuitry. Each controller has a set of control algorithms, including resident program instructions and calibrations stored in ROM and executed to provide the respective functions of each computer. Information transfer between the various computers may be accomplished using the aforementioned LAN.
In response to operator input, as captured by the UI, the supervisory HCP controller and one or more of the other controllers described above with respect to FIG. 1 determine required transmission output torque. Selectively operated components of the hybrid transmission 14 are appropriately controlled and manipulated to respond to the operator demand. For example, in the embodiment shown in FIG. 1 , when the operator has selected a forward drive range and manipulates either the accelerator pedal or the brake pedal, the HCP determines an output torque for the transmission, which affects how and when the vehicle accelerates or decelerates. Final vehicle acceleration is affected by other variables, including such factors as road load, road grade, and vehicle mass. The HCP monitors the parametric states of the torque-generative devices, and determines the output of the transmission required to arrive at the desired torque output. Under the direction of the HCP, the transmission 14 operates over a range of output speeds from slow to fast in order to meet the operator demand.
The ECU 80 also receives frequency signals from sensors for processing into input member 18 speed, N i , and output member 20 speed, N o , for use in the control of transmission 14 . The system controller may also receive and process pressure signals from pressure switches (not shown) for monitoring clutch application chamber pressures. Alternatively, pressure transducers for wide range pressure monitoring may be employed. Pulse-width modulation (PWM) and/or binary control signals are transmitted by the controller 80 to transmission 14 for controlling fill and drain of clutches C 1 -C 5 for application and release thereof.
Additionally, the controller 80 may receive transmission fluid sump temperature data, such as from thermocouple inputs (not shown), to derive a sump temperature. Controller 80 may provide PWM signals derived from input speed, N i , and sump temperature for control of line pressure via one or more regulators.
Fill and drain of clutches C 1 -C 5 may be effectuated, for example, by solenoid controlled spool valves responsive to PWM and binary control signals. Trim valves may be employed using variable bleed solenoids to provide precise placement of the spool within the valve body and correspondingly precise control of clutch pressure during apply. Similarly, one or more line pressure regulators (not shown) may be utilized for establishing regulated line pressure in accordance with the PWM signal. Clutch slip speeds across clutches may be derived from, for example: transmission input speed, output speed, motor A speed, and/or motor B speed.
The multi-mode, electrically-variable, hybrid transmission 14 is configured for several transmission operating modes. The truth table provided in FIG. 2 presents an exemplary engagement schedule (also referred to as a shifting schedule) of the torque-transmitting mechanisms C 1 -C 4 to achieve the array of operating states or modes. The various transmission operating modes described in the table indicate which of the specific clutches C 1 -C 4 are engaged (actuated), and which are released (deactivated) for each of the operating modes.
In general, ratio changes in transmission 14 may be performed such that torque disturbances are minimized, and the shifts are smooth and unobjectionable to the vehicle occupants. Additionally, release and application of clutches C 1 -C 4 should be performed in a manner which consumes the least amount of energy, and does not negatively impact durability of the clutches. One major factor affecting these considerations is the torque at the clutch being controlled, which may vary significantly in accordance with such performance demands as acceleration and vehicle loading. Improved shifts may be accomplished by a zero, or close to zero, torque condition at the clutches at the time of application or release, which condition follows substantially zero slip across the clutch. Clutches having zero slip across the clutch may be referred to as operating synchronously.
Electrically-variable operating modes may be separated into four general classes: input-split modes, output-split modes, compound-split modes, and series modes. In an input-split mode, one motor/generator (such as either motor A or motor B) is geared such that its speed varies in direct proportion to the transmission output, and another motor/generator (such as the other of motor A or motor B) is geared such that its speed is a linear combination of the input and output member speeds. In an output-split mode, one motor/generator is geared such that its speed varies in direct proportion to the transmission input member, and the other motor/generator is geared such that its speed is a linear combination of the input member and the output member speeds. A compound-split mode, however, has both motor/generators geared such that their speeds are linear combinations of the input and output member speeds, but neither is in direct proportion to either the speed of the input member or the speed of the output member.
Finally, when operating in a series mode, one motor/generator is geared such that its speed varies in direct proportion to the speed of the transmission input member, and another motor/generator is geared such that its speed varies in direct proportion to the speed of the transmission output member. When operating in series mode, there is no direct mechanical power transmission path between the input and output members and therefore all power must be transmitted electrically.
In each of the four general types of electrically-variable operating modes indicated above, the speeds of the motors are linear combinations of the input and output speeds. Thus, these modes have two speed degrees of freedom (which may be abbreviated for simplicity as “DOF”). Mathematically, the torque (T) and speed (N) equations of this class of modes take the form:
[ T a T b ] = [ a 1 , 1 a 1 , 2 a 2 , 1 a 2 , 2 ] [ T i T o ] and [ N a N b ] = [ b 1 , 1 b 1 , 2 b 2 , 1 b 2 , 2 ] [ N i N o ]
where a and b are coefficients determined by the transmission gearing. The type of EVT mode can be determined from the structure of the matrix of b coefficients. That is, if b 2,1 =b 1,2 =0 or b 1,1 =b 2,2 =0, the mode is a series mode. If b 1,1 =0 or b 1,2 =0, the mode is an input split mode. If b 2,1 =0 or b 2,2 =0, the mode is an output split mode. If each of b 1,1 , b 1,2 , b 2,1 , and b 2,2 are nonzero, for example, the mode is a compound split mode.
An electrically-variable transmission may also contain one or more fixed-gear (FG) modes. In general, FG modes result from closing (i.e., actuating) one additional clutch than the number required to select an electrically-variable mode. In FG modes, the speed of the input and each motor are proportional to the speed of the output. Thus, these modes have only one speed degree of freedom. Mathematically, the torque and speed equations of this class of modes take the form:
[ T b ] = [ a 1 , 1 a 1 , 2 a 1 , 3 ] [ T a T i T o ] and [ N a N b N i ] = [ b 1 , 1 b 1 , 2 b 1 , 3 ] [ N o ]
where a and b are again coefficients determined by the transmission gearing. If b 1,1 is nonzero, motor A can contribute to output torque during operation in the fixed-gear mode. If b 1,2 is nonzero, motor B can contribute to output torque during operation in the fixed-gear mode. If b 1,3 is nonzero, the engine can contribute to output torque during operation in the fixed-gear mode. If b 1,3 is zero, the mode is an electric-only fixed-gear mode.
An electrically-variable transmission may also be configured for one or more modes with three speed degrees of freedom. These modes may or may not include reaction torque sources such that the transmission is capable of producing output torque proportional to engine torque or motor torque. If a mode with three speed degrees of freedom is capable of producing output torque, the torques of the engine and any motor connected as a reaction to the engine torque will generally be proportional to the output torque. If a motor is not connected as a reaction to the engine torque, its torque can be commanded to control its speed independently of the transmission input and output speed.
In a mode with three speed degrees of freedom, it is generally not possible to easily control battery power independently of output torque. This type of mode produces an output torque which is proportional to each of the reacting torque sources in the system. The fraction of total output power provided by each of the three torque sources may be adjusted by varying the speeds of the motors and input. These modes are hereafter referred to as electric torque converter (ETC) modes in recognition of the fact that power flows to or from the energy storage device as a function of the output torque and the speed of the engine, output, and one of the motors. Mathematically, the torque and speed equations of this class of modes take the form:
[ T a T b T i ] = [ a 1 , 1 a 1 , 2 a 1 , 3 ] [ T o ] and [ N b ] = [ b 1 , 1 b 1 , 2 b 1 , 3 ] [ N a N i N o ]
where a and b are coefficients determined by the transmission gearing. If a 1,1 is nonzero, motor A serves as a reaction member and its torque is proportional to output torque when operating in the ETC mode. If a 1,1 is zero, motor A is disconnected and its torque is not determined by the output torque. If a 1,2 is nonzero, motor B serves as a reaction member and its torque is proportional to output torque when operating in the ETC mode. If a 1,2 is zero, motor B is disconnected and its torque is not determined by the output torque. If a 1,3 is nonzero, the engine can contribute to output torque during operation in the fixed-gear mode. If a 1,3 is zero, the input is disconnected and its torque is not determined by the output torque. If all of a 1,1 , a 1,2 , and a 1,3 are zero, the mode is a neutral mode that is not capable of producing output torque.
There are four neutral modes presented in FIG. 2 . In Neutral 1 , all clutches are released. Neutral 1 may be utilized when the entire vehicle is stopped and in an off-state, and thus there is no power distribution, electrical, mechanical, or otherwise, being actively distributed throughout the powertrain 10 . In Neutral 1 , a 12-volt starting-lighting-and-ignition (SLI) battery may be used for engine start.
In Neutral 2 , only clutch C 3 is engaged, and motor A and motor B may react engine 12 for start or to charge the energy storage device. Similar to Neutral 2 , when transmission 14 is in Neutral 3 , motor A and motor B may react engine 12 for start or to charge the energy storage device, and clutch C 4 as the only engaged torque-transmitting device. In Neutral 4 , the third and fourth clutches C 3 , C 4 are both in an activated state. In this instance, motor A is locked or “grounded”, and motor B is geared with the engine 12 for engine start.
The first and second planetary gear sets 24 , 26 cooperate with the first and second motor/generators 56 , 58 , along with the selective engagement of the first and second clutches C 1 , C 2 , to constitute an electric torque converter (ETC). For example, when the transmission 14 is operating in an ETC mode, the electric output of motor A and/or motor B, depending upon the active control schedule, can be adapted to control the transfer of torque from the engine 12 through the transmission differential gearing to the output member 20 . When the vehicle is started, ETC1 Mode is established by engaging the first clutch C 1 . In ETC1 Mode, motor A reacts engine 12 with the first and third planetary gear sets 24 , 28 , and motor B freewheels. In ETC1 Mode, the stationary vehicle can be smoothly started with the engine 12 held at a suitable speed by gradually increasing the amount of electric power generated by motor A—i.e., the reaction force of motor A.
There are two other alternative ETC modes available utilizing the transmission configuration presented herein. ETC2 Mode, also known as “compound ETC”, can be initiated by engaging clutch C 2 , and disengaging the remaining clutches. In ETC2 Mode, motor A reacts engine 12 with the first and third planetary gear sets 24 , 28 , while motor B reacts engine 12 and motor A to the output member 20 . The distribution of engine torque is manipulated through the cooperative management of the amount of electric power output generated by motor A and motor B.
The third ETC mode, ETC12 Mode, can be initiated by engaging both clutch C 1 and clutch C 2 . Similar to ETC1 Mode, motor A reacts the engine 12 with the first and third planetary gear sets 24 , 28 . However, in this instance, motor B is grounded to the transmission housing 60 . In ETC12 Mode, the vehicle can be smoothly accelerated with the engine 12 held at a suitable speed by gradually increasing the reaction force generated by motor A; which may be proportional to the electric power generated by motor A.
When the engine 12 is in an off-state, the transmission 14 can utilize the ETC mode clutch control schedule to vary the amount of electric energy generated by motor A so as to gradually increase the drive torque of motor A and/or motor B. For example, if the transmission 14 is shifted into ETC1 Mode when the engine 12 is in an off-state, the engine 12 will create a reaction force, by way of input member 18 . The motive output of the motor A can then be controlled, and a continuous and uninterrupted transmission output torque maintained, without having to turn the engine 12 on.
The exemplary powertrain 10 described herein has three fixed-gear (FG), or “direct,” modes of operation. In all fixed-gear modes of this embodiment of transmission 14 , the vehicle is driven in the forward direction by operation of the engine 12 . The selective engagement of clutches C 1 , C 3 and C 4 shifts the transmission 14 into FG1 Mode. In FG1, motor A is grounded, and the engine drives the first planetary gear set 24 to the third planetary gear set 28 and, thus, the output member 20 . FG2 Mode is achieved by the selective engagement of clutches C 1 , C 2 and C 4 . In FG2, motor B is grounded, and the engine drives the first and second planetary gear sets 24 , 26 to the third planetary gear set 28 and, thus, the output member 20 . Likewise, FG3 Mode is achieved by the selective engagement of clutches C 2 , C 3 and C 4 . In FG3, motor A is locked, and the engine drives the first planetary gear set 24 to the second and third planetary gear sets 26 , 28 and the output member 20 . When operating in a fixed-gear mode of operation, the output member speed N o is directly proportional to input member speed N i and the selected gear ratio. N i =N o ×GR.
With continued reference to FIG. 2 , the transmission 14 may also operate in four electrically-variable transmission (EVT) modes. In EVT1 and EVT4, the transmission 14 is operating in an input-split mode of operation, wherein the output speed N o of the transmission 14 is proportional to the speed of one motor/generator 56 , 58 (motor A or motor B). Specifically, EVT1 Mode is achieved through the selective engagement of the first and third clutches C 1 and C 3 . When in EVT1, motor A functions to react the engine 12 with the first planetary gear set 24 , to the third planetary gear set 28 , and the output member 20 ; while motor B drives the second and third planetary gear sets 26 , 28 . Motor A propels the vehicle in EVT1. Alternatively, the transmission 14 may be selectively shifted into EVT4 Mode by actuating clutch C 2 and clutch C 3 . In EVT4, motor A functions to react the engine 12 with the first planetary gear set 24 , to the second and third planetary gear sets 26 , 28 , and the output member 20 , while motor B drives the second and third planetary gear sets 26 , 28 . Motor B propels the vehicle in EVT4.
In EVT2 and EVT3, the transmission 14 is operating in a compound-split mode, wherein the output speed N o of the transmission 14 is not proportional to the speed of a single motor/generator, but is rather an algebraic linear combination of the speeds of both motor/generators. More particularly, EVT2 is achieved through the selective engagement of the first and fourth clutches C 1 , C 4 . In this mode, motor A and motor B operate to react the engine 12 with the first and second planetary gears sets. Alternatively, the transmission 14 may be selectively shifted into EVT3 Mode by actuating clutch C 2 and clutch C 4 . When operating in EVT3 Mode, the two motor/generator assemblies 56 , 58 react the engine 12 with all three planetary gear sets 24 , 26 , 28 .
With reference to FIG. 3 , a plot of transmission output speed, N o , along the horizontal axis versus input speed, N i , across the vertical axis is illustrated. FIG. 3 is only a graphical representation of exemplary regions of operation for each operating mode with respect to input and output speeds of this embodiment of transmission 14 .
Synchronous operation in FG1—the input speed and output speed relationships where clutches C 1 , C 3 and C 4 are operating with substantially zero slip speed thereacross—is represented by line 91 . As such, line 91 represents an input and output speed relationship at which substantially synchronous shifting between EVT modes can occur. FG1 is also a range at which direct mechanical coupling from input to output can be effected by simultaneous application of clutches C 1 , C 3 and C 4 —i.e., fixed- or direct-ratio.
Synchronous operation in FG2—the input speed and output speed relationships where clutches C 1 , C 2 and C 4 are operating with substantially zero slip speed thereacross—is represented by line 93 . Similarly, the relationships between input and output speed during operation in FG3, whereat clutches C 2 , C 3 and C 4 are operating simultaneously with substantially zero slip speed there across, is represented by line 95 .
To the left of the shift ratio line 91 is an exemplary region of operation for the first EVT mode, EVT1, wherein both C 1 and C 3 are applied, and C 2 and C 4 are released. To the right of the shift ratio line 91 and left of shift ratio line 93 is an exemplary region of operation for the second EVT mode, EVT2, wherein C 1 and C 4 are applied, and C 2 and C 3 are released.
To the right of shift line 93 and left of shift ratio line 95 is an exemplary region of operation for the third EVT mode, EVT3, wherein both C 2 and C 4 are applied, and C 1 and C 3 are released. To the right of the shift ratio line 95 is an exemplary region of operation for the fourth EVT mode, EVT4, wherein C 2 and C 3 are applied, and C 1 and C 4 are released. As used herein with respect to clutches C 1 -C 5 , the terms “applied” or “actuated” indicate substantial torque transfer capacity across the respective clutch. Antithetically, the terms “released” or “deactivated” indicate insubstantial or no torque transfer capacity across the respective clutch.
While the regions of operation specified above may be generally favored for operation of the hybrid transmission 14 , it is not meant to imply that the various EVT regions of operation depicted in FIG. 3 cannot or do not overlap. Generally, however, it may be preferred to operate in the specified regions because each particular mode of operation preferably employs gear sets and motor hardware particularly well suited in various aspects (e.g., mass, size, cost, inertial capabilities, etc.) for that region. Similarly, while the individual regions of operation specified above are generally preferred for the particular modes of operation indicated, it is not meant to imply that the regions of operation for the individual EVT modes cannot be switched.
Generally, a shift into Mode 1 may be considered a downshift and is associated with a higher gear ratio in accordance with the relationship of N i /N o . In contrast, a shift into Mode 4 is considered an upshift, and is associated with a lower gear ratio in accordance with the relationship of N i /N o . As discussed herein, other mode-to-mode shift sequences are feasible. For example, a shift from EVT1 to EVT3 is also an upshift, while a shift from EVT4 to EVT2 is considered a downshift.
Referring now to FIG. 4 , and with continued reference to FIGS. 1-3 , there is shown a schematic illustration of an exemplary pressure control system 100 for feeding transmission fluid to the hydraulic circuit of the transmission 14 shown in FIG. 1 . The pressure control system 100 supplies transmission fluid to a hydraulic circuit, partially shown at 102 , which supplies transmission fluid for clutches C 1 -C 5 , and transmission lubrication and cooling systems.
The pressure control system 100 includes first and second fluid pumps: a main pump 104 and an auxiliary pump 106 . The main and auxiliary pumps 104 and 106 draw transmission fluid from a sump 108 , which may also operate as an exhaust for other portions of the hydraulic circuit.
The main pump 104 , which may also be referred to as an engine pump, derives power from the engine 12 through belt, gearing, or other driving connection to the engine output shaft. Therefore, the main pump 104 is not operational when engine 12 is not running at sufficient speeds to operate the main pump, and main pump 104 is completely off when engine 12 is turned off—such as when transmission 14 is operating on electric-only motive power.
Auxiliary pump 106 operates independently from the engine 12 , and may, therefore, operate while the engine 12 is off or running at very low speeds. The word “auxiliary” is often shortened to “aux” and is used interchangeably herein. Aux pump 106 is either self-powered (having a motor incorporated therein) or is powered by an electric motor (not shown). The electric motor may be dedicated solely to operation of the aux pump 106 , and draws power from the energy storage device associated with powertrain 10 or a dedicated battery (not shown).
Fluid from the main pump 104 flows into a main channel 110 , and fluid from the aux pump 106 flows into an auxiliary channel 112 . The channels 110 , 112 converge at a control valve 116 before entering hydraulic circuit 102 .
The pressure of the transmission fluid passing through the channels 110 , 112 from the main and aux pumps 104 , 106 is controlled by first and second regulators in order to regulate the pressure of fluid entering the hydraulic circuit 102 . Generally, regulators are units which, with a pressure variable inlet pressure, give substantially constant output pressure provided that the inlet pressure remains higher than the required outlet pressure.
A main regulator 120 maintains substantially constant fluid pressure in the main channel 110 , as long as the pressure generated by the main pump 104 exceeds the control pressure of the main regulator 120 . Similarly, an auxiliary regulator 122 maintains substantially constant fluid pressure in the aux channel 112 , as long as the pressure generated by the aux pump 106 exceeds the control pressure of the aux regulator 122 . Structure and processes for controlling the main and aux regulators 120 , 122 are described in more detail herein. Depending upon the application-specific configuration chosen, both main and auxiliary regulators may be considered either the first regulator or the second regulator.
Fluid flow from the main and aux pumps 104 , 106 enter hydraulic circuit 102 via the control valve 116 . In the embodiment shown in FIG. 4 , control valve 116 selectively allows substantially exclusive fluid flow communication with hydraulic circuit 102 from only one of the channels 110 , 112 at a time.
The control valve 116 may be an exclusive- or (‘XOR’) configuration. In an XOR embodiment, control valve 116 is mechanized to control flow of hydraulic fluid from the aux pump 106 and the main pump 104 by permitting flow of pressurized fluid into the hydraulic circuit 102 of the transmission 14 substantially exclusively from either the aux pump 106 or the main pump 104 , depending upon operating conditions of pressure and flow from each of the pumps. For short periods of time, control valve 116 may allow fluid flow to the hydraulic circuit 102 from both of channels 110 , 112 ; or may allow small amounts of fluid from one channel while the other is selected or placed in control; but under most operating conditions, fluid flow will be exclusive from one or the other of the channels 110 , 112 .
FIG. 4 schematically shows the control valve 116 in position to allow fluid flow communication between the hydraulic circuit 102 and the aux pump 106 , while substantially blocking flow from the main pump 104 through channel 110 . This indicates that FIG. 4 represents an operating mode in which the engine 12 is not powering the main pump 104 . The conditions shown schematically in FIG. 4 may be indicative of an EVT mode, or other mode in which the vehicle is being propelled solely by tractive power from motor A or B ( 56 , 58 ).
Main and aux regulators 120 , 122 control the pressure in channels 110 and 112 , respectively, in accordance with a control signal. The control signal is a hydraulic fluid pressure signal sent from a single pressure control solenoid (PCS) 124 through signal channels 126 . Each of the regulators 120 , 122 varies its maximum pressure as a function of the pressure in signal channels 126 . PCS 124 is controlled by an electronic communication from a controller 128 , determined by ECU 80 or another part of the hybrid control system based upon operating conditions of the powertrain 10 .
Through this control structure, a single control device (PCS 124 ) receiving a single electronic signal can control two (or more) regulators. Furthermore, this one pressure signal can result in different pressure value outputs by changing the response functions of the individual regulators 120 , 122 .
Referring now to FIG. 5 , and with continued reference to FIGS. 1-4 , there is shown an exemplary graph 200 of two possible control functions for the regulated output pressure of the main and aux regulators 120 , 122 as a function of PCS 124 control pressure communicated through signal channels 126 . The exact functions shown in FIG. 5 exemplary, and are meant only to demonstrate two possible control functions resulting in different values for the main and aux regulators 120 , 122 .
On the x-axis (horizontal) of graph 200 is the value of the pressure signal being communicated by the signal channels 126 from PCS 124 , show in kilopascal (kPa). The y-axis (vertical) is the pressure of the main or aux regulators 120 , 122 , shown in kPa. Line 202 traces the pressure of the main regulator 120 as a function of the pressure of PCS 124 . The function upon which line 202 is based is: Main(PCS)=2*PCS. Line 204 traces the pressure of aux regulator 122 as a function of the pressure of PCS 124 . The function upon which line 204 is based is: Aux(PCS)=PCS+150.
Note that across a majority of the operating region shown in graph 200 —specifically, any PCS ( 124 ) pressure greater than approximately 150 kPa—the main regulator 120 is set to a higher pressure than the aux regulator 122 . When PCS 124 is set to 350 kPa, aux regulator 122 has a resulting output of 500 kPa (shown as horizontal line 206 ); at the same PCS ( 124 ) pressure, however, main regulator 120 has a resulting output of 700 kPa (shown as horizontal line 208 ).
Referring now to FIGS. 6A and 6B , and with continued reference to FIGS. 1-5 , there are shown graphical representations of exemplary control processes for transitions between the main and auxiliary pumps 104 , 106 shown in FIG. 4 . FIG. 6A shows a transition from pressurizing the hydraulic circuit 102 exclusively with the main pump 104 to pressurizing exclusively with the aux pump 106 . Similarly, FIG. 6B shows a transition from pressurizing hydraulic circuit 102 exclusively with aux pump 106 to pressurizing exclusively with the main pump 104 .
FIG. 6A shows a graph 300 plotting input speed, N i , as shown on line 302 , PCS command on line 306 , and hydraulic circuit pressure on line 304 , against time on the x-axis (horizontal). The transition begins at a start point 310 as the internal combustion engine 12 is commanded to begin a transition to an engine-off state, as shown by the decrease in input speed N i and line 302 . The transition generally takes place between the start point 310 and an end point 312 , both marked with dashed vertical lines and coinciding to changes in input speed N i as the engine 12 transitions from on to off, or the reverse.
Prior to start point 310 , the PCS 124 is operating in a low state, which may be approximately 250 kPa. Referring again to FIG. 5 , while PCS 124 is set to the low position or state, the main regulator 120 has a pressure of approximately 500 kPa, and aux regulator 122 has a pressure of approximately 400 kPa. For illustrative purposes only, it may be assumed that transmission 14 requires approximately 500 kPa to properly operate clutches C 1 -C 5 and to cool components of the transmission 14 . Therefore, in order to maintain operation of powertrain 10 , the hybrid control system will attempt to maintain constant pressure in the hydraulic circuit 102 of at least 500 kPa. This is the target pressure of the hybrid control system.
At start point 310 , control valve 116 will place (or have already placed) channel 110 , and flow from the main regulator 120 , in substantially exclusive fluid flow communication with hydraulic circuit 102 . Control valve 116 selects flow from the main regulator 120 because the auxiliary regulator 122 is set to allow lower pressure (400 kPa versus 500 kPa from main regulator 120 ). Furthermore, the aux pump 106 may be in an off state while the engine 12 is running and the main pump 104 is capable of fully-pressurizing hydraulic circuit 102 .
As input speed N i decreases, the ability of main pump 104 to maintain 500 kPa of pressure will also decrease, and eventually main pump 104 will be in a non-operating state. Therefore, the hybrid control system will command the aux pump 106 to transition to an auxiliary-on state at or before start point 310 , in order to take over control of the hydraulic circuit 102 immediately as the main pump 104 is no longer able to maintain the target pressure of 500 kPa. Referring again to FIG. 5 , in order for the aux regulator 122 to provide 500 kPa, the PCS 124 must be set to a high position. For the function shown on line 204 of FIG. 5 , the high position of the PCS 124 is 350 kPa.
Moving PCS 124 to the high position causes the main regulator 120 to increase its maximum allowable pressure in channel 110 to 700 kPa. Note that, referring to FIG. 4 , signal channels 126 communicate the PCS control signal to both the main and aux regulators 120 , 122 . Therefore, while PCS 124 is set to the high position in order to increase the maximum pressure from the aux regulator 122 , because there is only one PCS, the main regulator 120 pressure also increases. Maintaining both regulators ( 120 , 122 ) at the elevated level—caused by the high PCS setting—causes an increase in the line pressure of hydraulic circuit 102 , shown as portion 304 a in FIG. 6A .
Main regulator 120 will continue to output 700 kPa until the input speed N i decreases to a level that renders the main pump 104 incapable of maintaining 700 kPa of pressure. The aux pump 106 reaches full capacity (auxiliary-on) prior to the point at which the main pump 104 is incapable of maintaining the target pressure.
The pressure in channel 110 will then decrease to zero as input speed N i decreases to zero. As the pressure in channel 110 decreases to below 500 kPa, the control valve 116 will handoff fluid flow communication with the hydraulic circuit 102 to channel 112 and aux regulator 122 . Main pump 104 will lose the ability to generate 500 kPa prior to input speed N i falling to zero and the main pump 104 moving to a completely-inoperable state. For example, this may occur at an input speed of 200 rpm, shown in FIG. 6A as horizontal line 314 . At this point, the transition is complete and the line pressure of hydraulic circuit 102 will be maintained at the target pressure substantially exclusively by the aux pump 106 .
FIG. 6B shows the transition from pressurizing hydraulic circuit 102 exclusively with aux pump 106 to pressurizing exclusively with the main pump 104 . This transition may occur after the transition shown in FIG. 6A , or may be an independent transition.
A graph 350 shows input speed, N i , on line 352 , PCS command on line 356 , and hydraulic circuit ( 102 ) pressure on line 354 , plotted against time on the x-axis. The transition begins at a start point 360 as the internal combustion engine 12 is commanded to begin a transition from the engine-off state to an engine-on state, as shown by the increase in input speed N i . The transition generally takes place between the start point 360 and an end point 362 , both marked with dashed vertical lines and coinciding with changes in input speed N i as engine 12 transitions from off to on.
Prior to start point 360 , while the transmission 14 is operating on electric-only power, PCS 124 is operating in the high state (approximately 350 kPa), placing the aux regulator 122 and main regulator 120 in respective high pressure settings. At start point 360 , control valve 116 will place (or have already placed) channel 112 , and flow from the aux regulator 122 , in substantially exclusive fluid flow communication with hydraulic circuit 102 , because the pressure from main pump 104 will be negligible.
As input speed N i increases, the ability of main pump 104 to maintain 500 kPa of pressure will also increase, and eventually main pump 104 will be able to take over pressurization hydraulic circuit 102 . Because PCS 124 is in the high position, the main regulator 120 allows maximum pressure in channel 110 of 700 kPa. As input speed N i increases above a minimum speed (represented by line 364 , which may be approximately 200 rpm), main pump 104 will create enough pressure to exceed the 500 kPa maximum allowed by the aux regulator 122 .
Flow handoff to the main pump 104 will occur as the control valve 116 registers that the pressure from main pump 104 in channel 110 exceeds the pressure from aux pump 106 in channel 112 . However, in order to maintain the target pressure in hydraulic circuit 102 , PCS 124 remains in the high position until the main pump 104 is fully operational. Because PCS 124 is still set to the high position, the continued increase in input speed Ni will continue to cause the line pressure in hydraulic circuit 102 to increase up to the maximum of 700 kPa allowed by the main regulator 120 . This pressure increase is shown as portion 354 a of line 354 in FIG. 6B .
Following complete flow handoff to the main pump 104 , the auxiliary pump 106 may be commanded to an auxiliary-off state. Furthermore, the PCS 124 may then move from the high position to the low position. As the signal channel 126 causes the main regulator 120 to move back to its low pressure setting, the line pressure in hydraulic circuit 102 returns to 500 kPa, as shown by the portion of line 354 to the right of end point 362 .
While the best modes and other modes for carrying out the present invention have been described in detail, those familiar with the art to which this invention pertains will recognize various alternative designs and embodiments for practicing the invention within the scope of the appended claims. | A method of pressure control for transmissions having a hydraulic circuit selectively communicating with first and second pumps via first and second regulators includes commanding communication to the hydraulic circuit to transition from the first to the second pump and the PCS to set the regulators to a high pressure-regulation level. The hydraulic circuit line pressure is raised to an elevated value exceeding a target value. The line pressure is lowered from the elevated to the target value at or after completing the transition to the second pump. The method may include transitioning communication with the hydraulic circuit from the second to the first pump. The PCS maintains the regulators at the high level and line pressure is raised to the elevated value. PCS sets the regulators to a low level, and line pressure returns to the target only at or after completing the transition to the first pump. | 5 |
INTRODUCTION
This invention relates to cycle exercisers and is particularly applicable to such exercisers that either alternatively or simultaneously exercise the muscles of the legs and lower torso and muscles of the arms and upper torso.
Normal cycle exercisers suffer a disadvantage in that they only make use of the muscles of the legs and lower torso of the user. They do, of course, impose a modest desirable added burden on the circulatory system and the oxygen transport system of the body. Present emphasis on exercises of a more active nature such as jogging or aerobic exercises are intended to increase the burden on those body systems while exercising a greater variety of muscle groups.
Cycle exercisers have been developed that offer the user exercise of the upper torso in a rowing motion and even a motion that combines rowing with a twisting of the torso by requiring one's arms to reach to different distances; the basic motion of these exercisers is that of rowing and most of them require no significant effort by the upper muscles, the motion of these upper muscles being driven by the action of the leg muscles through the exercise equipment.
More recently, two cycle exercisers have been developed wherein an energy absorbing wheel is driven, either alternatively or simultaneously by the legs and the arms acting through the exercise machine. As these exercisers are driven by the arms, the arms act in alternating fashion (as in a swimming motion) rather than in simultaneous fashion, as in the aforementioned rowing motion. The intent is clearly to offer a greater degree of exercise to the muscle groups of the upper body and to do so in a manner that can be used to drive an energy absorbing wheel using the arm motion alone, without leg motion. These exercisers suffer from certain disadvantages relating to their basic design. These disadvantages are overcome in the present invention.
U.S. Pat. No. 4,188,030, by Hooper, teaches the use of a mechanical link between each handle bar and an eccentric on the pedal shaft to create alternating motion of the separate handle bars in a swimming motion and provides that the handle bars may be used to drive the energy absorbing wheel, with or without the use of the leg muscles. A positive feature of this invention is that the motions of the handle bars are synchronized with the motions of the pedals. A disadvantage is that there is no way to stop pedaling and rest the feet on the pedals while driving the energy absorbing wheel by means of the handlebars.
U.S. Pat. No. 4,657,244, by Ross, teaches another approach to linking the handlebars to the energy absorbing wheel, this time by means of gears associated with only the wheel, which wheel is simultaneously or alternatively driven by chains and sprockets linking it to a standard pedal crank. A significant disadvantage seen in the Ross exerciser is the lack of synchronized action of the arms and the legs, especially in embodiments wherein a one-way clutch is employed to provide for resting either the hands or the feet on their respective drive elements while continuing to operate the exerciser by using the non-resting pair of extremities. In such instances, even if chain sprocket and gear ratios provide for synchronization, the one-way clutch may easily disrupt such synchronization.
This invention affords another type of cycle exerciser that can provide exercise for both the lower and upper part of the body, but which differs from other such exercisers in that it uses a different system for mounting the arm levers and for linking them to the driven wheel.
SUMMARY OF THE INVENTION
In its simplest embodiment, the cycle exerciser of this invention is constructed in the manner of a conventional cycle exerciser with a frame, a seat, foot pedals, a principal chain drive system, and an energy absorbing flywheel. Additionally, extending outward from the axle of the flywheel on one side thereof is a first sprocket for engagement by a drive chain, which sprocket rotates with the flywheel. A second sprocket fixedly attached to a second drive shaft rotatably carried by the frame is positioned so as to align with the first sprocket and a drive chain links these two sprockets. Eccentric means on each end of said second drive shaft engage a pivot means that in turn engages a reciprocating arm. Movement of the reciprocating arms by the user will cause rotation of the second drive shaft, causing the attached second sprocket to drive the first sprocket and, consequently, to drive the flywheel. Thus the wheel of this cycle exerciser may be driven by the arms of the user as well as by his legs, thereby providing exercise for the upper part of the body as well as the lower part of the body.
In a more advanced embodiment of this invention, a jackshaft is interposed between the flywheel and the principal chain drive system to increase the rotational speed of the flywheel and means are provided for the pedals and reciprocating arms to apply rotational forces that are synchronized. In the best mode of this embodiment, the jackshaft drive train includes a free-wheeling clutch capable of delivering torque to the flywheel, but incapable of having the flywheel deliver torque to the drive system (i.e., pedals and arms), thereby to allow the user to abruptly stop exercising without the flywheel causing the pedals and reciprocating arms to continue their motion.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a right-side elevational view of a front-wheel cycle exerciser modified to include the present invention.
FIG. 2 is a right-side elevational view of a front-wheel cycle exerciser built to include the present invention in its preferred mode.
FIG. 3 is an exploded view of the two drive shafts of the present invention and their associated drive means in the preferred mode.
FIG. 4 is a cross sectional view showing the interconnection between crank arms and arm levers of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
The reciprocating arm levers and second drive shaft construction of this invention can be attached to any conventional cycle exerciser. Even modified cycle exercisers, wherein the flywheel is mounted other than in front of the user could be adapted to include the reciprocating arm levers construction of this invention. For purposes of simplicity, the instant invention will be described in conjunction with the features of a typical front-wheeled cycle exerciser.
A typical cycle exerciser, as is shown in FIG. 1, wherein such an exerciser has been modified to include the present invention, includes a frame 12, comprising a base 14, a front support 16, a rear support 18, a seat support 20, and the seat 22. The frame 12 may be made of tubes, as shown in FIG. 1, or it may be made of plates or other structures that will provide a solid support for the cycle exerciser. The frame 12 is preferably made of metal, but other materials may also be suitable. Any conventional bicycle seat may be used on a cycle exerciser.
The typical cycle exerciser also includes right and left foot pedals 24, each mounted on a crank arm 26 attached to a main drive shaft 28 upon which is mounted a primary sprocket 30. Alternating force by the user of the cycle exerciser on the right and then the left foot pedals causes rotation of the main drive shaft 28 and the primary sprocket 30. A continuous chain loop 32 is passed over the primary sprocket 30 at one end and a secondary sprocket 34 at the other end, which secondary sprocket is usually directly attached to an energy absorbing flywheel 36. Thus, in the typical cycle exerciser, the effort expended upon cranking the pedals 24 is transmitted by the primary sprocket 30 to the drive chain 32 and thence to the secondary sprocket 34 and the flywheel 36 where it is dissipated in some controlled fashion. I refer to this chain drive train as the principal chain drive system. Any of the conventional other systems that are currently in use for cycle exercisers may also be used to link the pedals 24 to the flywheel 36. In most instances it is desirable to place chainguards (not shown) over the drive chains to prevent contact of the sprockets or chain with the body or the clothing, thereby to keep the body and the clothing from becoming soiled or injured as a result of such contact.
Flywheels or energy absorbing wheels of many types are used on various typical cycle exercisers, including those using air resistance as in Hooper, braking devices as in Lee (U.S. Pat. No. 4,235,436), or roller devices as in another patent that was issued to Lee (U.S. Pat. No. 4,206,914). No attempt is made here to illustrate or describe the details of an energy absorbing wheel, and no limitation thereon should be inferred from the drawings attached hereto.
"Speedometers", ergometers, "odometers", clocks, timers, or other instrumentation are often added to the typical cycle exerciser to provide information to the user to gage his energy output or the duration of his exercise. The instant invention does not preclude the use of any of the aforementioned features of the typical cycle exerciser, although the features may take on a modified form to be functional when the reciprocating arm levers of the instant invention are added.
A significant feature of the present invention is that the energy absorbing wheel 36 need not be in front of the user, although the arm levers that may be used to drive the wheel are definitely in front of the user. The energy absorbing wheel 36 may even be absent and replaced by another energy absorbing device, such as a pump or a dynamo, for examples, and these may be mounted wherever is convenient for mounting, as long as they may be linked by drive chain to both the primary sprocket 30 associated with the pedals and to the sprocket later described as being associated with the handle bars. This feature becomes a decided advantage in situations where alternate energy absorbing means are employed. For purposes of simplicity, however, I shall confine my description to a cycle exerciser having a front-mounted energy absorbing wheel.
The simplest embodiment of the present invention could be adapted for use on a standard cycle exerciser, resulting in what I shall call a modified cycle exerciser as shown in FIG. 1. In this modified cycle exerciser, the front wheel 36, being driven by the customary principal chain drive system, rotates on an axle 37 whose distal end portions extend out of the right and left sides of the front wheel 36. On at least one of the end portions of this axle is mounted a sprocket 38 that turns as the wheel 36 and the secondary drive sprocket 34 turn. Over this additional first sprocket 38 a continuous chain 39 is passed that also engages a second sprocket 40 on a substantially horizontal second drive shaft 42 having two ends thereof rotatably secured to the frame 12. A crank arm 44 is secured to each of two opposite end portions of this second drive shaft, the two crank arms extending laterally from the drive shaft 42 in opposite directions. As will be further described below, this second drive shaft is to be linked to reciprocating arm levers 45 for exercising muscle groups in the upper torso and the arms. In this modified cycle exerciser, the sprocket tooth ratio of this first and second sprocket set is exactly the inverse of the sprocket tooth ratio of the principal chain drive system that transmits energy from the pedal system to the wheel; thus the second drive shaft 42 turns in exact synchrony with the primary drive shaft 28 to which the pedals are connected, thereby coordinating arm and leg motions, which motions are generally desired to be in a predetermined phase relationship during exercising both upper torso and lower torso muscle groups.
In this modified cycle exerciser, separate left and right reciprocating arm levers 45 are pivotally attached on each respective side of the frame 12 in front of the user, as at 46. This pivotal attachment is generally made above the aforementioned second drive shaft 42 and a length of each lever extends below the point of attachment and is slotted as shown in detail in FIG. 4 to receive a rotational bearing means 50 that will slide lengthwise in the slot 51 while being retained therein. Alternatively, the pivotal attachment may be made below the second drive shaft and a length of each lever proximal the cyclical path of the end of said crank arm is slotted lengthwise to receive the bearing means. Referring again to FIG. 4, from the end of each crank arm 44 associated with the second drive shaft 42 there protrudes a pin 52 or bearing stud, fixedly attached to the crank arm, and upon which pin the said rotational bearing means 50 is mounted. This bearing means is slidably engaged with the slot 51 in the corresponding reciprocating arm lever 45, thereby linking the pin and the arm lever in sliding and rotational contact.
As this modified cycle exerciser is pedaled by the user, the pedals turn the principal drive chain 32 system that turns the wheel 36; the turning of the wheel causes the first sprocket 38 to drive, by means of the chain linking them, the second sprocket 40 and second drive shaft 42 at the same rotational velocity (speed and direction) as the primary sprocket 30 and first drive shaft 28 driven by the pedals; the protruding pin 52 fixedly attached to the crank arm 44 of the second drive shaft 42 causes a reciprocating motion of the arm levers 45 through said rotational bearing means 50, which motion is in synchrony with the pedal motion. Alternatively, the user may operate the arm levers 45 in reciprocating fashion, thereby driving the second drive shaft 42, the second sprocket 40 and thus the first sprocket 38 and the flywheel 36. A one-way clutch may be included in the principal chain drive system to allow the user to stop pedaling while driving the wheel using the arm levers, but the clutch should be of a type that would ensure the desired synchronization of the revolving of the pedals and the reciprocating of the arm levers. A clutch mechanism could alternatively be interposed between the flywheel 36 and both the principal chain drive system and the chain drive associated with the arm levers 45, thereby allowing pedaling and arm motions to both be stopped while the flywheel continues to turn. A variety of such arrangements could be made to provide for immediate stopping of either pedaling or arm motions or both pedaling and arm motions without waiting for the energy stored in the flywheel to be dissipated. Means for such clutches have long been available. This concludes my discussion of a cycle exerciser modified according to my teachings of the present invention.
In a preferred embodiment of the present invention, illustrated in FIGS. 2, 3, and 4, the primary 60 and secondary 61 sprockets of the principal chain drive system are equal in diameter and tooth count, therefore they always turn in synchrony. A jackshaft 62 is driven by a second sprocket 64 connected to and therefore turning with either the primary sprocket 60 or the secondary sprocket 61 of the principal chain drive system. The jackshaft 62 comprises a first jackshaft sprocket 66 somewhat smaller than the said second sprocket 64 (that turns with the sprockets of the principal chain drive system) and a second jackshaft sprocket 68 somewhat larger than the first jackshaft sprocket and mounted on a common axle 70 therewith. The second jackshaft sprocket 68, which turns with the first jackshaft sprocket 66, is linked by a drive chain to a sprocket 72 attached to and turning with the flywheel 76. Generally this flywheel sprocket 72 is smaller than the second jackshaft sprocket 68. Thus, one skilled in the art would recognize that the jackshaft arrangement herein described causes the flywheel 76 to turn at a speed greater than that of the primary sprocket 60 of the principal chain drive system. In this embodiment, a one-way clutch mechanism could be incorporated on the jackshaft axle 70 or on the axle of the flywheel 78. This one-way clutch mechanism would allow the user of the cycle exerciser to immediately stop pedaling while the flywheel continues to turn as the rotational energy stored therein is dissipated. Such a clutch could be incorporated in the principal drive train, in the drive train associated with the reciprocating arm levers, or one in each of these drive trains.
In this preferred embodiment, as illustrated in FIGS. 2, 3, and 4, the reciprocating arm levers 45 are linked to the secondary sprocket 61 by means of a pair of crank arms 44 attached to the axle of the secondary sprocket 61 (via the second drive shaft 42), one on each side of the front upright supports, which crank arms are similar to the pedal crank arms except that in place of each pedal on the crank arm, there protrudes a pin 52, or bearing stud, fixedly attached to the crank arm 44, and upon which pin the said rotational bearing means 50 is mounted. This bearing means is slidably engaged with the slot 51 in the corresponding reciprocating arm lever 45, thereby linking the pin and the arm lever in sliding and rotational contact.
It should be clear from this description that, although the reciprocating arm levers 45, the secondary sprocket 34 of the principal chain drive system, and its associated crank arms 44 must all be positioned in front of the user to allow the arm levers to be in convenient position for operation by the user, there is no requirement for the jackshaft 62 and the flywheel 76 to be in any specific location. Indeed, a pump or a dynamo might be the energy absorbing means associated with the exerciser of this invention and the flywheel may be a part of such ancillary equipment.
In the best mode, however, it is convenient to place the flywheel 76 before the user of the cycle exerciser, where it is on a common axis with the secondary sprocket 61 of the principal chain drive system and its associated crank arm 44 linking it to the arm levers 45. In this embodiment, the flywheel 76, although coaxial with other operating members, is turning at a higher speed that the others. This is accomplished by providing bearings 80 to isolate the drive shaft 42 of the crankarm assembly from the hollow axle of the faster-rotating flywheel 36, through which hollow the crankarm drive shaft extends.
Now, having described my invention in detail sufficient that one skilled in the art could duplicate the mechanism and reproduce my results, and having included detail applicable to specific non-limiting examples, I request protection under letters patent for my invention as limited only by the scope of the claims hereto appended. | This invention relates to cycle exercisers and is particularly applicable to such exercisers that either alternatively or simultaneously exercise the muscles of the legs and lower torso and muscles of the arms and upper torso. Arm levers for propelling the energy absorbing wheel of a cycle exerciser, do so by acting on crank arms through rotating slidable bearing means operating in slots in the arm levers; the crank arms are connected to a second drive shaft that is linked to the wheel by chain drive means. | 8 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] This invention relates to an apparatus that may be used in wells during drilling operations. More particularly, a valve having a full-opening bore that may be placed in a tubular such as casing and operated mechanically to isolate pressure when it is closed is provided.
[0003] 2. Description of Related Art
[0004] Drilling of wells in an underbalanced or balanced pressure condition has well-known advantages. In this condition, pressure in the formation being drilled is equal to or greater than pressure in the wellbore. When there is a need to withdraw the drill pipe from the well, pressure in the wellbore must be controlled to prevent influx of fluids from a formation into the wellbore. The usual remedy of preventing influx of fluid from a formation—by increasing fluid density in the wellbore—may negate the advantages of balanced or underbalanced drilling. Therefore, downhole valves have been developed to isolate fluid pressure below the valve. They have been variously called “Downhole Deployment Valves” (DDV) or “Downhole Isolation Valves” (DIV). Technical literature includes reports of the usage of such valves in Under-Balanced Drilling (UBD) For example, SPE 77240-MS, “Downhole Deployment Valve Addresses Problems Associated with Tripping Drill Pipe During Underbalanced Drilling Operations,” S. Herbal et al, 2002, described uses of such valves in industry. The DDV or DIV as a tool in the broad area of “Managed Pressure Drilling” can be generally surmised from the survey lecture “Managed Pressure Drilling,” by D. Hannagan, SPE 112803, 2007. There it is listed under “Other Tools” and called a “Downhole Casing Isolation Valve” (DCIV) or “Downhole Deployment Valve.” Services and products for providing Managed Pressure Drilling have been commercialized by AtBalance of Houston, Tex., Weatherford International, Inc. of Houston, Tex. and other companies.
[0005] A DCIV is placed in a casing at a selected depth, considering conditions that may be encountered in drilling the well. The valve is normally placed in an intermediate casing string, and the effective Outside Diameter (OD) of the valve is limited by the Inside Diameter (ID) of the surface casing through which it must pass. For example, in 9⅝-inch intermediate casing, the valve preferably will be full-opening (have a bore at least equal to the ID of the 9⅝ inch casing, about 8.681 inches, or at least be as large as the drill bit to be used) and must pass through the drift diameter of the surface casing, which may be 10.5 inches. Therefore, the valve must be designed to severely limit the thickness of the valve body while being large enough for a bit to pass through.
[0006] A DCIV is disclosed in U.S. Pat. No. 6,209,663. A flapper valve is illustrated, but other types of valves, such as ball valves or other rotary valves are disclosed. The valves may be mechanically operated or operated by biasing means (e.g., springs). U.S. Pat. No. 6,167,974 discloses a flapper-type DCIV valve that is operated by a shifting device that is carried on a drill bit and deposited in the valve when the drill string is tripped out of the well.
[0007] Prior art valves relying on a flapper mechanism have been commercially successful, but improvements in reliability and absence of leakage are needed. A rotary valve having minimum difference between outside diameter and inside diameter is needed. The ability of the valve to seal with differential pressure in two directions is also preferred.
[0008] It should be understood that valves designed for downhole isolation may also be used for a variety of purposes. In wells, there may be a need to open or close a valve to control pressure near the bottom of the well when the hydrostatic pressure of fluid in the well is higher than desired, or there may be a need to isolate pressure in a well bore drilled from another well bore. In industry, valves requiring a minimum of wall thickness between the interior passage through the valve and the exterior surface of the valve may be needed for a variety of applications in any industry utilizing mechanical techniques.
SUMMARY OF INVENTION
[0009] A mechanically activated, bi-directional (will isolate fluid pressure in either direction) valve is disclosed, referred to herein as the Mechanical Bi-directional Isolation Valve (MBIV). The valve element is mounted on a hinge plate assembly. As a protective sleeve exposes the “Wedgelock” (sealing element having curved surfaces), the hinge plate assembly will move the valve into the closed position. When the protective sleeve moves in the opposite direction, the hinge plate assembly will move the Wedgelock into the open position. After closing, the valve is locked into position by a locking sleeve to isolate fluid pressure differential across the valve in either direction.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] FIG. 1 is a sketch of a well having an MBIV in an intermediate casing.
[0011] FIG. 2 is a composite drawing showing the segments in the following detailed drawings of the valve in the open position.
[0012] FIG. 3 is a composite drawing showing the segments in the following detailed drawings of the valve in the closed position.
[0013] FIGS. 2 a - 2 h illustrate the valve disclosed herein in the open position.
[0014] FIGS. 3 a - 3 h illustrate the valve disclosed herein in the closed position.
[0015] FIG. 4 is an isometric view of the “Wedgelock” in the open position.
[0016] FIG. 5 is an isometric view of the Wedgelock hinge assembly.
[0017] FIG. 6 is an isometric view of the Wedgelock in the partially closed position.
[0018] FIG. 7 is an isometric view of a protective sleeve with an upper valve seat area.
[0019] FIG. 8 is an isometric view of the Wedgelock.
[0020] FIG. 9 is an isometric view of a lower valve seat with valve seat area.
[0021] FIG. 10 is an isometric view of a hinge plate for the Wedgelock.
[0022] FIG. 11 is an isometric view of a spring for the Wedgelock.
[0023] FIG. 12 is an isometric view of a split ring of the valve assembly.
[0024] FIG. 13 is an isometric view of the spring-loaded actuation assembly on the bottom-hole assembly.
DETAILED DESCRIPTION
[0025] FIG. 1 illustrates well 10 that is being drilled. As an example, surface casing 12 has been placed in the well. Intermediate casing 14 , containing the MBIV 20 , used as a downhole casing isolation valve, has also been placed in the well. Inside diameter 21 of the MBIV 20 must be large enough to allow passage of drill bit 16 on the drill pipe 15 . The MBIV 20 disclosed here is adapted to allow a lesser difference in diameter between the inside diameter 21 of MBIV 20 and the inside diameter of intermediate casing 14 than is allowed by downhole isolation valves cited in the references disclosed above. MBIV 20 is mechanically actuated by actuation assembly on the BHA 22 as drill bit 16 and drill pipe 15 travel in and out of the well 10 .
[0026] The MBIV assembly is illustrated in sectional views 2 a - 2 h and 3 a - 3 h . In FIG. 2 , the valve is in the open position and in FIG. 3 it is in the closed position Some parts of the valve assembly extend over multiple figures.
[0027] FIG. 2 a shows upper connection housing 130 . Threads on upper connection housing 130 are adapted for joining to the casing in which the MBIV 20 is to be employed.
[0028] FIG. 2 b shows upper connection housing 130 which is joined to the uphole end of upper release housing 126 . Upper release housing 126 is joined to intermediate housing 85 on its downhole end. This joining may be a threaded connection, as shown. Upper locking sleeve 110 is placed in upper release housing 126 . Upper locking sleeve split ring 118 is expanded into upper release housing downhole split ring groove 117 . Upper release housing uphole split ring groove 116 is also shown. FIG. 2 b also shows upper locking sleeve actuation groove 112 with upper locking sleeve actuation groove uphole chamfer 113 and upper locking sleeve actuation groove downhole chamfer 114 , which are used for locking the tool.
[0029] FIG. 2 c shows intermediate housing 85 connected to the upper release housing 126 on its uphole end and to spline housing 68 on its downhole end. This joining may be a threaded connection. Upper locking sleeve 110 and upper locking tube 88 are located inside intermediate housing 85 . Upper locking fingers 120 are shown in the unlocked position on the outside diameter of upper locking tube 88 . Upper locking groove 102 , located on the outside diameter of upper locking tube 88 , is also shown. FIG. 2 c also shows the upper locking tube actuation groove 103 and the upper locking tube actuation groove uphole chamfer 104 located on the inside diameter of the upper locking tube 88 . Upper positioning ring 122 shouldering on the intermediate housing shoulder limit 125 is also shown.
[0030] FIG. 2 d shows spline housing 68 connected to intermediate housing 85 on its uphole end and carrier sleeve housing 80 on its downhole end. This joining may be a threaded connection. Upper locking tube actuation groove downhole chamfer 105 is located on the inside diameter of upper locking tube 88 and protective sleeve 52 is located inside the spline housing 68 . Upper locking tube 88 with intermediate housing shoulder limit A 101 is also shown.
[0031] FIG. 2 e shows carrier sleeve housing 80 connected to spline housing 68 on its uphole end and to the “Wedgelock” housing 84 on its downhole end. This joining may be a threaded connection. Carrier sleeve housing 80 contains the connection between upper locking tube 88 and valve body 97 . Shown also are protective sleeve shoulder limit 51 of protective sleeve 52 to spline housing 68 , and a pressure equalization configuration consisting of protective sleeve 52 , protective sleeve pressure equalization ports 64 , valve body pressure equalization ports 98 , carrier housing pressure equalization cavity 91 and valve body pressure equalization seal 100 . Shown also is protective sleeve actuation groove 54 , protective sleeve actuation groove uphole chamfer 56 and protective sleeve actuation groove downhole chamfer 57 . Valve body split ring 99 is placed on the inside diameter of valve body 97 and may be expanded into protective sleeve uphole split ring groove 58 . Protective sleeve downhole split ring groove 59 is also shown.
[0032] The term “Wedgelock” is used herein to identify the sealing element of the valve. It preferably has two curved surfaces, and may be formed by machining curved surfaces from round stock, the surfaces being separated by the selected thickness of the valve element, to form a “saddle-like” shape. The thickness is selected according to the pressure differential expected across the valve.
[0033] FIG. 2 f shows Wedgelock housing 84 connected to carrier sleeve housing 80 on its uphole end and to lower locking housing 41 on its downhole end. Wedgelock 70 and hinge assembly 72 , shown in the open position, is covered by protective sleeve 52 and debris sleeve 50 forming Wedgelock pocket 82 . Any joining connection may be threaded. Shown also are valve body 97 with lower valve seat 96 , lower lock housing split ring 86 , lower locking tube open split ring groove 94 , valve body shoulder limit 106 and lower lock housing shoulder limit 43 .
[0034] FIG. 2 g shows lower lock housing 41 joined to the Wedgelock housing 84 on its uphole end and to lower connection housing 36 on its downhole end. This joining may be a threaded connection. Lower locking tube 92 also contains the lower locking sleeve 30 with open locking groove 93 on its outside diameter, lower locking fingers 40 and lower positioning ring 45 . FIG. 2 g also shows lower connection housing split ring 39 , positioned in lower connection housing 36 , expanding into lower connection housing open split ring groove 37 and lower connection housing closed split ring groove 38 . Shown also are lower locking tube closed split ring groove 95 , lower locking sleeve actuation groove 32 , lower locking sleeve actuation groove downhole chamfer 34 lower locking sleeve actuation groove uphole chamfer 33 , lower lock housing shoulder limit 44 and lower connection housing shoulder limit 42 .
[0035] FIG. 2 h shows intermediate housing 85 connected to lower connection housing 36 on its downhole end. This connection may be a threaded connection. FIG. 2 h also shows the lower end of the lower locking sleeve 30 with the lower locking sleeve actuating groove 32 .
[0036] FIG. 3 a shows upper connection housing 130 . Threads on upper connection housing 130 are adapted for joining to the casing in which MBIV 20 is to be employed.
[0037] FIG. 3 b shows upper connection housing 130 , which is joined to upper release housing 126 on its uphole end and to intermediate housing 85 on its downhole end. This joining may be a threaded connection as shown. Upper locking sleeve 110 is located in upper release housing 126 . Upper locking sleeve split ring 118 is expanded into upper release housing uphole split ring groove 116 . Upper release housing downhole split ring groove 117 is also shown. FIG. 3 b also shows upper locking sleeve actuation groove 112 with upper locking sleeve actuation groove uphole chamfer 113 and upper locking sleeve actuation groove downhole chamfer 114 used for locking the tool. In the closed position upper locking tube 88 is shown.
[0038] FIG. 3 c shows intermediate housing 85 connected to the upper release housing 126 on its uphole end and to spline housing 68 on its downhole end. This joining may be a threaded connection. Upper locking sleeve 110 and the upper locking tube 88 are located inside intermediate housing 85 . Upper locking fingers 120 are shown in the locked position on the outside diameter of upper locking tube 88 . Upper locking groove 102 located on the outside diameter of upper locking tube 88 is also shown. FIG. 3 c also shows upper locking tube actuation groove 103 , upper locking tube actuation groove uphole chamfer 104 and upper locking tube actuation groove downhole chamfer 105 located on the inside diameter of upper locking tube 88 . Upper positioning ring 122 shouldering on intermediate housing shoulder limit 125 is also shown.
[0039] FIG. 3 d shows spline housing 68 connected to intermediate housing 85 on the uphole end and carrier sleeve housing 80 on the downhole end. This joining may be a threaded connection. Protective sleeve 52 is located inside intermediate housing 85 . Shown also is upper locking tube 88 with intermediate housing shoulder limit 101 , protective sleeve 52 with protective sleeve actuation groove 54 , protective sleeve actuation groove uphole chamfer 56 and protective sleeve actuation groove downhole chamfer 57 .
[0040] FIG. 3 e shows carrier sleeve housing 80 as shown connected to spline housing 68 on its uphole end and to wedgelock housing 84 on its downhole end. This joining may be a threaded connection. Carrier sleeve housing 80 contains the connection between the upper lock tube 88 and the valve body 97 . Shown also are protective sleeve shoulder limit 51 of protective sleeve 52 connected to spline housing 68 , an overpressure equalization arrangement consisting of protective sleeve pressure equalization polls 64 , valve body pressure equalization ports 98 , carrier housing pressure equalization cavity 91 , and valve body pressure equalization seal 100 . The lower portion of FIG. 3 e shows debris sleeve 50 , hinge assembly 72 and “Wedgelock” 70 in the closed position. Valve body split ring 99 , located on the inside of valve body 97 , and expands into the protective sleeve uphole split ring groove 58 . Protective sleeve downhole split ring groove 59 is also shown.
[0041] FIG. 3 f shows Wedgelock housing 84 connected to carrier sleeve housing 80 on its uphole end and to lower locking housing 41 on its downhole end Wedgelock 70 and hinge assembly 72 are shown in the closed position. Any joining connection may be threaded. Shown also is valve body 97 with lower valve seat 96 , lower lock housing split ring 86 , lower locking tube open split ring groove 94 , lower locking tube closed split ring groove 95 , lower lock housing shoulder limit 43 , valve body shoulder limit 106 and lower locking tube 92 .
[0042] FIG. 3 g shows lower lock housing 41 joined to the Wedgelock housing 84 on the uphole end and to lower connection housing 36 on it downhole end. This joining may be a threaded connection. Lower locking tube 92 also contains lower locking sleeve 30 with open locking groove 93 on its outside diameter, lower locking fingers 40 and lower positioning ring 45 . FIG. 3 g also shows lower connection housing split ring 39 , positioned in the lower connection housing 36 , expanding into lower connection housing closed split ring groove 38 lower connection housing open split ring groove 37 . Shown also are lower lock housing shoulder limit 44 , lower connection housing shoulder limit 42 , lower locking sleeve actuation groove 32 with lower locking sleeve actuation groove downhole chamfer 34 and lower locking sleeve actuation groove uphole chamfer 33 .
[0043] FIG. 3 h shows intermediate housing 85 connected to the lower connection housing 36 on its downhole end. This connection may be a threaded connection. FIG. 3 h also shows the lower end of lower locking sleeve 30 with lower locking sleeve actuating groove 32 .
[0044] FIG. 4 shows an isometric view of Wedgelock 70 in the open position with upper valve seat area 62 .
[0045] FIG. 5 shows an isometric view of hinge assembly 72 with springs 74 , sliding hinge 78 and a hinge pin 73 .
[0046] FIG. 6 shows an isometric view of Wedgelock 70 in the closing position.
[0047] FIG. 7 shows an isometric view of protective sleeve 52 and upper valve seat area 62 .
[0048] FIG. 8 shows an isometric view of Wedgelock 70 with guide pin track 63 .
[0049] FIG. 9 shows an isometric view of lower valve seat 96 with lower valve seat area 90 and guide pins 61 .
[0050] FIG. 10 shows an isometric view of sliding hinge 78 .
[0051] FIG. 11 shows an isometric view of a spring 74 .
[0052] FIG. 12 shows an isometric view of a typical split ring.
[0053] FIG. 13 shows an actuation assembly that may be mounted on BHA 22 and drill pipe 15 to actuate the valve mechanisms when drill pipe 15 and drill bit 16 move through the valve. Retractable, spring-loaded dogs 23 are adapted to enter actuation grooves in the valve that are identified below, which applies forces to move the various elements of the valve.
[0054] To move MBIV 20 from the open position to a closed position after drill bit 16 , FIG. 1 , is raised to a location below the MBIV 20 , BHA 22 moves through lower locking sleeve 30 , ( FIG. 2 g, h ) which will permit spring-loaded dogs 23 mounted on the bottom-hole assembly (BHA) 22 to expand into lower locking sleeve actuation groove 32 , which will then move lower locking sleeve 30 ( FIG. 2 g, h ) uphole. When force F exceeds a predetermined force F 1 , set by geometry of lower connection housing open split ring groove 37 and geometry of lower connection housing split ring 39 in lower connection housing 36 , disengages from the lower connection housing open split ring groove 37 , then lower locking sleeve 30 with connection housing split ring 39 moves uphole and engages with the lower connection housing closed split ring groove 38 . This unlocks lower locking fingers 40 from open locking groove 93 located on the outside of lower locking tube 92 , which enables lower locking tube 92 to freely move uphole. Lower locking tube 92 may be considered to be part of an inner locking tube assembly that consists of lower locking tube 92 , lower valve seat 96 , valve body 97 and upper locking tube 88 . As drill bit 16 continues to travel uphole, spring-loaded dogs 23 on the BHA 22 exert an increasing force F onto lower locking sleeve actuation groove uphole chamfer 33 of lower locking sleeve actuation groove 32 . As force F continues to increase and exceeds a predetermined force F 2 , spring-loaded dogs 23 on BHA 22 will collapse and disengage from the lower locking sleeve actuation groove 32 .
[0055] As drill bit 16 travels uphole, spring-loaded dogs 23 on BHA 22 will exert a force, engage with inside diameter of debris sleeve 50 and move debris sleeve 50 ( FIG. 2 f ) uphole. The drill string continues to move uphole until spring loaded dogs 23 on BHA 22 expand into protective sleeve actuation groove 54 ( FIG. 2 e ) located on the protective sleeve 52 . Continuing the uphole movement, valve body split ring 99 may engage with split ring grooves to allow controlled movements of protective sleeve 52 . This will move protective sleeve 52 uphole with drill bit 16 until protective sleeve 52 reaches protective sleeve shoulder limit 51 in spine housing 68 . As drill bit 16 continues to travel uphole, spring-loaded dogs 23 on BHA 22 exert a force F onto protective sleeve actuation groove uphole chamfer 56 until spring-loaded dogs 23 on the BHA 22 exceed a predetermined limit force F 3 , collapsing and disengaging spring-loaded dogs 23 on BHA 22 from protective sleeve actuation groove 54 .
[0056] The movement of protective sleeve 52 uphole will open Wedgelock pocket 82 , which provided space for Wedgelock 70 in the open position. As this area becomes exposed, Wedgelock 70 is moved into the valve bore area by a force that may be generated by springs 74 mounted on one or more floating hinge assemblies 72 .
[0057] As drill bit 16 continues to travel uphole, spring-loaded dogs 23 on BHA 22 move to and expand into upper locking tube actuation groove 103 ( FIG. 2 d ). Force F is exerted by lower lock housing split ring 86 , located inside lower lock housing 41 , onto lower locking tube open split ring groove 94 in lower locking tube 92 until it exceeds a predetermined force F 4 and disengages. Upper locking tube 88 moves uphole with drill bit 16 . Guide pins 61 ( FIG. 9 ) engage with guide pin track 63 ( FIG. 8 ) located on the downhole side of Wedgelock 70 , which positions lower valve seat area 90 with Wedgelock 70 into upper valve seat area 62 ( FIGS. 4 , 7 ), located on protective sleeve 52 to establish bi-directional seating. Simultaneously, valve body split ring 99 expands into protective sleeve uphole split ring groove 58 . Wedgelock 70 is mounted on axially floating hinge assembly 72 .
[0058] As drill bit 16 travels uphole, spring-loaded dogs 23 on the BHA 22 exerts a force F onto upper locking tube actuation groove uphole chamfer 104 ( FIG. 2 c ), located on upper locking tube 88 until it disengages from upper locking tube actuation groove 103 .
[0059] As drill bit 16 continues to travel further uphole, spring-loaded dogs 23 on the BHA 22 move to and expand into upper locking sleeve actuation groove 112 located on upper locking sleeve 110 ( FIG. 2 b ) Upper locking sleeve 110 moves uphole with drill bit 16 until a force F from upper locking sleeve split ring 118 exceeds a predetermined limit force F 6 and disengages from upper release housing downhole split ring groove 117 located on upper release housing 126 . As movement continues further uphole, upper locking sleeve split ring 118 will expand into upper release housing split ring groove 116 located on upper release housing 126 . Simultaneously, upper locking sleeve 110 moves over upper locking fingers 120 and forces upper locking fingers 120 to collapse into upper locking groove 102 ( FIG. 2 c ) located on upper locking tube 88 . This locks MBIV 20 into the closed position.
[0060] The spacing, S, between the bottom of drill bit 16 and spring-loaded dogs 23 is a determining factor in the overall length of MBIV 20 . The spacing between Wedgelock 70 and protective sleeve actuation groove 54 must be greater than the spacing S.
[0061] To move MBIV 20 from a closed position to an open position after drill bit 16 , FIG. 1 , is lowered to a location above the MBIV 20 , drill bit 16 moves into upper locking sleeve 110 . spring-loaded dogs 23 mounted on BHA 22 will expand into upper locking sleeve actuation groove 112 ( FIG. 3 b ), moving the upper locking sleeve 110 downhole. Upper locking sleeve split ring 118 , located in upper locking sleeve 110 , disengages from upper release housing uphole split ring groove 116 and expands into upper release housing downhole split ring groove 117 . As upper locking sleeve 110 is guided downhole, it disengages upper locking fingers 120 from upper locking groove 102 . This unlocks MBIV 20 from the closed position.
[0062] When upper locking sleeve 110 reaches the intermediate housing shoulder limit B 125 ( FIG. 3 c ), a force F, is exerted by spring-loaded dogs 23 mounted on BHA 22 on upper locking sleeve actuation groove downhole chamfer 114 . When force F exceeds a predetermined force F 8 , spring-loaded dogs 23 on BHA 22 then collapse and disengage from upper locking sleeve actuation groove 112 and continue to travel downhole.
[0063] As actuation assembly on the BHA 22 travels downhole, it will expand into upper lock tube actuation groove 103 and start to move upper locking tube 88 downhole. When valve body equalization seal 100 shifts into the carrier housing pressure equalization cavity 91 , downhole pressure is then released into valve body pressure equalization port 98 . The excess pressure is discharged through the protective sleeve pressure equalization port 64 into the well bore uphole of Wedgelock 70 . The pressure on both sides of Wedgelock 70 is now equalized for safe MBIV 20 operation. Increasing the actuation force F will disengage lower lock housing split ring 86 from lower locking tube closed split ring groove 95 . Lower lock housing split ring 86 will then expand into the lower locking tube open split ring groove 94 . During this operation, lower valve seat 96 moves away from Wedgelock 70 . Actuation tool assembly on the BHA 22 continues to travel downhole until valve body 97 reaches its lower lock housing shoulder limit 43 . A force F is then exerted onto the upper locking tube actuation groove downhole chamfer 105 . When force F exceeds predetermined force F 9 spring-loaded dogs 23 on the BHA 22 collapse and disengage from upper locking tube actuation groove 103 .
[0064] As actuation assembly on BHA 22 travels downhole, it will expand into protective sleeve actuation groove 54 located in protective sleeve 52 . As protective sleeve 52 begins to move downhole, valve body split ring 99 will disengage from protective sleeve downhole split ring groove 59 due to exceeding a force F 10 . Protective sleeve 52 will then continue to move downhole and expand into protective sleeve uphole split ring groove 58 . During this movement downhole, protective sleeve 52 will drive Wedgelock 70 from upper valve seat area 62 . Wedgelock 70 will shift and rotate from the closed position into the open position. After protective sleeve 52 reaches valve body shoulder limit 106 Wedgelock 70 will be contained in Wedgelock pocket 82 and will be isolated from the flow path by protective sleeve 52 . Actuation tool assembly on BHA 22 exerts a force F onto the protective sleeve actuation groove downhole chamfer 57 until it exceeds a predetermined force F 11 , collapsing and disengaging from the protective sleeve actuation groove 54 .
[0065] Spring-loaded dogs 23 on BHA 22 continue to travel downhole engaging and moving debris sleeve 50 downhole until it reaches valve body shoulder limit 106 in order to cover the downhole end of protective sleeve 52 .
[0066] As spring-loaded dogs 23 on BHA 22 continue to travel further downhole, they expand into lower lock sleeve actuation groove 32 located in the lower lock sleeve 30 . As lower lock sleeve 30 moves downhole, a force F is exerted onto the lower connection housing split ring 39 until it disengages from lower connection housing closed split ring groove 38 and expands into the lower connection housing open split ring groove 37 . As lower lock sleeve 30 moves downhole it slides over the lower locking fingers 40 and forces them to collapse into open locking groove 93 . Lower lock sleeve 30 moves downhole until it comes in contact with lower connection housing shoulder limit 42 . Spring-loaded dogs 23 on BHA 22 start to exert a force F onto lower locking sleeve actuation groove downhole chamfer 34 . When force F exceeds a predetermined limit F 12 , spring-loaded dogs 23 on BHA 22 collapse and disengage from lower locking sleeve actuation groove 32 . The MBIV 20 is now locked into the open position.
[0067] The actuation mechanism on the drill pipe that moves the elements of the valve as the drill pipe and drill bit are moved in and out of the wellbore has been illustrated here as spring-loaded dogs 23 on the BHA 22 , but it should be understood that the invention disclosed is not limited to a particular actuation mechanism. For example, the actuation mechanism on the drill pipe that exerts a force to operate the valve may be other spring-loaded or pressure-loaded mechanical arrangements or it may be hydraulically or electrically powered by other apparatus placed on the drill pipe 15 or BHA 22 . A signal to operate the valve actuation mechanism or to turn off the valve actuation mechanism may be programmed into apparatus placed on the drill pipe or may be transmitted from the surface.
[0068] Although the present invention has been described with respect to specific details, it is not intended that such details should be regarded as limitations on the scope of the invention, except as and to the extent that they are included in the accompanying claims. | A valve having a sealing surface that is rotated 90 degrees on axial floating hinge assemblies is provided. A sleeve moves into position to protect the valve mechanism when the valve is in an open position. A sleeve locks the valve sealing element in place in either a closed or open position. The valve may be used during drilling of wells to prevent flow into the casing when the drill pipe and bit are raised above the valve. | 4 |
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of U.S. application Ser. No. 10/113,745 filed on Apr. 1, 2002 by Buysse et al. entitled “BIPOLAR ELECTROSURGICAL INSTRUMENT FOR SEALING VESSELS” which is a continuation-in-part of U.S. application Ser. No. 10/090,081 filed on Mar. 1, 2002 by Buysse et al. entitled “BIPOLAR ELECTROSURGICAL INSTRUMENT FOR SEALING VESSELS” which is a continuation of U.S. application Ser. No. 09/502,933 filed on Feb. 11, 2000 by Buysse et al. entitled “BIPOLAR ELECTROSURGICAL INSTRUMENT FOR SEALING VESSELS” which is a continuation of U.S. application Ser. No. 08/968,779 filed on Nov. 12, 1997 by Buysse et al. entitled “BIPOLAR ELECTROSURGICAL INSTRUMENT FOR SEALING VESSELS”, the entire contents of all of these applications are incorporated by reference herein in their entirety.
BACKGROUND
[0002] 1. Field of the Invention
[0003] This invention relates to an electrosurgical instrument for permanently closing vessels in a human or animal, and more particularly to a bipolar electrosurgical instrument that seals vessels and vascular tissue by applying a combination of pressure and electrosurgical current.
[0004] 2. Background of Related Art
[0005] A hemostat is commonly used in surgical procedures to grasp, dissect and clamp tissue. It is typically a simple pliers-like tool that uses mechanical action between its jaws to constrict vessels without cutting them. It is also typical for hemostats to have an interlocking ratchet between the handles so that the device can be clamped and locked in place.
[0006] Many hemostats are used in a typical open-surgical procedure. Once vascular tissue has been clamped with a hemostat, it is common for a surgeon to tie a suture around the tissue to close it off permanently prior to removing the hemostat. Several hemostats may be left in the surgical field until the surgeon has the opportunity to tie a suture around each section of clamped tissue.
[0007] Small blood vessels have been closed using electrosurgical instruments without the need for sutures. For example, neurosurgeons have used bipolar instruments to coagulate vessels in the brain that are smaller than two millimeters in diameter. These bipolar instruments are typically tweezers-like devices with two arms that can be deflected toward each other to grasp tissue. However, it has been found that these instruments are not capable of sealing blood vessels with diameters larger than about two millimeters. There has been a long-felt need for an easy way to seal larger vessels and vascular tissue bundles without the need for sutures.
[0008] It is thought that the process of coagulating small vessels is fundamentally different than vessel sealing. Coagulation is defined as a process of desiccating tissue wherein the tissue cells are ruptured and dried. Vessel sealing is defined as the process of liquefying the collagen in the tissue so that it crosslinks and reforms into a fused mass. Thus, coagulation of small vessels is sufficient to permanently close them. Larger vessels need to be sealed to assure permanent closure.
[0009] A number of bipolar electrosurgical forceps and clamps are known in the field. However, these instruments are not designed to apply the correct pressure to a blood vessel to achieve a lasting seal. All of these instruments also suffer from the drawback that they do not combine the simplicity and familiarity of a hemostat with a bipolar electrosurgical circuit.
[0010] An example of a bipolar electrosurgical power curve for vessel sealing is disclosed in a U.S. Patent application entitled, “Energy Delivery System for Vessel Sealing,” Ser. No. 08/530,495, filed Sep. 19, 1995, and is hereby incorporated by reference and made a part of this disclosure.
[0011] A U.S. Patent application entitled, “Vascular Tissue Sealing Pressure Control and Method,” Ser. No. 08/530,450, filed on Sep. 19, 1995, discloses another surgical tool for sealing vessels, and is hereby incorporated by reference and made a part of this disclosure.
[0012] U.S. Pat. No. 371,664 discloses a pair of electric forceps with positive and negative electric poles located on the jaws.
[0013] U.S. Pat. No. 728,883 discloses an electrothermic instrument in which electricity is used to heat one of the jaws of the instrument.
[0014] U.S. Pat. No. 1,586,645 discloses a bipolar instrument for coagulating tissue.
[0015] U.S. Pat. No. 2,002,594 discloses a bipolar laparoscopic instrument for treating tissue, whereby coagulation and cutting of tissue can be performed with the same instrument.
[0016] U.S. Pat. No. 2,176,479 discloses an instrument for finding and removing metal particles. The jaws of the instrument are designed to complete an electrical circuit when conductive material is placed therebetween. An insulated pivot and an insulated ratchet are used to prevent a short circuit.
[0017] U.S. Pat. No. 3,651,811 discloses a bipolar electrosurgical instrument for cutting and coagulating tissue.
[0018] U.S. Pat. No. 4,005,714 discloses bipolar coagulation forceps with jaws that open and close by way of an actuating sleeve.
[0019] U.S. Pat. Nos. 4,370,980 and 5,116,332 disclose an electrocautery hemostats wherein the hemostatic clamping function and the electrocautery function may be accomplished with a single instrument. Monopolar electrosurgical designs are shown and described.
[0020] U.S. Pat. No. 4,552,143 discloses a family of removable switch electrocautery instruments, including an electrocautery hemostat. Monopolar electrosurgical designs are shown and described.
[0021] U.S. Pat. No. 5,026,370 discloses an electrocautery forceps instrument having an enclosed electrical switching mechanism. Monopolar electrosurgical designs are shown and described.
[0022] U.S. Pat. No. 5,443,463 discloses coagulating forceps having a plurality of electrodes.
[0023] U.S. Pat. No. 5,484,436 discloses bipolar electrosurgical instruments for simultaneously cutting and coagulating tissue.
[0024] The article, “The Mechanism of Blood Vessel Closure by High Frequency Electrocoagulation” discloses experiments upon the blood vessels of dogs. The sentence starting on the last line of page 823 describes “an electrode forceps, each of the blades being insulated form the other and each connected to a terminal of the high frequency generator.”
[0025] The article, “Studies on coagulation and development of an automatic computerized bipolar coagulator” discloses on page 150 that, “It was not possible to coagulate safely arteries with a diameter larger than 2 to 2.5 mm.” On page 151, line 5 , it is noted that “Veins can be coagulated safely up to a diameter of 3 to 4 mm.”
[0026] Russian Patent 401,367 discloses a bipolar instrument with a linkage that brings the working jaws together in a parallel manner.
[0027] Prior disclosures have not provided a design for a bipolar electrosurgical instrument capable of conveniently applying a constant pressure, from a calibrated spring-loaded source held by a ratchet, that is sufficient to seal vessels and vascular tissue.
SUMMARY OF THE INVENTION
[0028] It is the general objective of this invention to provide a bipolar electrosurgical instrument that can fuse tissue without the need for a suture or surgical clips. The instrument conducts electrosurgical current between two seal surfaces located on opposable jaws. The electrosurgical current passes through tissue clamped between the jaws and remolds the collagen to fuse the tissue and form a permanent seal.
[0029] One advantage of the invention is that blood vessels can be quickly fused and permanently sealed against passage of blood or other fluids. The instrument thereby reduces operating-room time, provides improved access to target tissues, and increases the efficiency of the surgical procedure.
[0030] Another advantage is that no sutures or staples are required to permanently seal blood vessels, and no foreign material is left in the body of the patient.
[0031] Yet another advantage is that vessels can be sealed as the instrument is applied, and then the instrument can be removed from the surgical field. This keeps the surgical field clear of extraneous tools that may hinder the surgeon's access to the surgical site.
[0032] Yet another advantage is that the proper amount of pressure can be applied by the instrument to the vessel or vessels, thereby increasing the likelihood of a successful surgical outcome.
[0033] The bipolar electrosurgical instrument of the present invention comprises inner and outer members connected by an open lockbox, interlocking ratchet teeth, and electrical terminals with conductive pathways leading to seal surfaces. The inner and outer members each have a ring handle near a proximal end and an opposable seal surface near a distal end. The proximal end is held and controlled by the surgeon, while the distal end is used to manipulate tissue. The open lockbox joins the inner and outer members to allow arcuate motion of each opposable seal surface. The open lockbox is generally designed to provide lateral support so that both seal surfaces move in approximately the same plane. The seal surfaces are preferably aligned opposite each other when the instrument jaws are closed together. To provide lateral support, the open lockbox comprises a pivot and at least one flange extending over the inner member and attached to the outer member.
[0034] The instrument is tuned to provide a proper closure force by adjusting the dimensions of a shank portion on each of the inner and outer members. The shank portion is defined as the portion of each member bounded by its respective ratchet stub and the open lockbox. During use, the surgeon squeezes the ring handles to compress tissue between the seal surfaces. The shank portion of each member flexes in the manner of a cantilever spring, and can be locked in a deflected position with the ratchet to hold a constant force. It is one of the objects of the invention to provide a range of ratchet stops that correspond to a range of appropriate closure forces on the seal surfaces of the instrument.
[0035] Ratchet teeth are located on each member near the ring handle. The ratchet teeth are generally designed to interlock against the spring force from the shanks. The spring force is thus transmitted through the pivot to hold the seal surfaces against each other. A range of closure forces is required in an instrument, depending on the type and thickness of the tissue to be sealed. It is thus desirable to have several ratchet stops, each providing a progressively larger force to the seal surfaces.
[0036] An electrical connector is located on each ring handle. The electrical connector may be a metal post that is integrally formed with the member and ring handle. Bipolar electrical cables from an electrosurgical generator are connected to the instrument at the electrical connectors. An electrically conductive path on each of the inner and outer members conducts the electrosurgical current to the seal surfaces. The electrically conductive path may be along the stainless steel members. An electrically insulative coating is preferably bonded to the outer surfaces of the members to protect the surgeon and patient against inadvertent electrical burns.
[0037] The following terms are herein defined as follows. The applied force of the instrument is the total force being applied to the tissue between the jaws. The jaws are the members near the distal end of the instrument, from the lockbox to the tip of the instrument. The electrodes are the metal surfaces that conduct electricity to the tissue. The seal surface is the feature on the electrode that comes in direct contact with the tissue. The shank is the portion of each member between the lockbox and the ratchet. The ring handles are the elements on the members, near the proximal end of the instrument, that are grasped by the surgeon. The lockbox is the structure that allows the members to pivot, including the pivot pin and other cooperating surfaces. The inner member is the member that is generally captured in the interior of the lockbox. The outer member is the member that is on the outside of the lockbox. Electrode pressure is calculated by dividing the applied force over the complete area of the seal surface. Tissue pressure is calculated by dividing the applied force over the area of tissue placed between the jaws.
[0038] It has been found through experimentation that an instrument for vessel fusion (also referred herein as vessel sealing) should compress the tissue with a proper amount of pressure between the instrument jaws. The pressure is preferably sufficient to close any blood-carrying lumen. The pressure is preferably low enough so that the tissue is not split apart within the instrument jaws.
[0039] The jaws of the instrument should not short-circuit during the procedure. The tissue will typically decrease in thickness when electrosurgical current is applied, thereby allowing the seal surfaces to move closer together. This decrease in thickness should not result in the electrodes making direct contact with each other. Otherwise, a short circuit could give the electrosurgical current a preferential path around the tissue and may result in a poor seal.
BRIEF DESCRIPTION OF THE DRAWINGS
[0040] [0040]FIG. 1 is a perspective view of a bipolar instrument for vessel fusion, shown partially exploded.
[0041] [0041]FIG. 2 is a schematic plan view of a bipolar instrument for vessel fusion having a longer curved jaw.
[0042] [0042]FIG. 3 is a side view of the instrument shown in FIG. 2.
[0043] [0043]FIG. 4 is a schematic plan view of an alternative embodiment of an instrument for vessel fusion having a shorter curved jaw.
[0044] [0044]FIG. 5 is side view of the instrument shown in FIG. 4.
[0045] [0045]FIG. 6 is a schematic plan view of an alternative embodiment of an instrument for vessel fission having a straight jaw.
[0046] [0046]FIG. 7 is a side view of the instrument shown in FIG. 7.
[0047] [0047]FIG. 8 is a perspective view of a shoulder pin.
[0048] [0048]FIG. 9 is a side view of a shoulder pin.
[0049] [0049]FIG. 10 is a front view of a shoulder pin.
[0050] [0050]FIGS. 11A and 11B is a top view each of a pair of seal surfaces showing conductive regions and insulative regions that prevent a short circuit when the seal surfaces are mated in opposition.
DETAILED DESCRIPTION OF THE INVENTION
[0051] Referring to FIG. 1, the instrument 10 has an inner member 11 and an outer member 12 . The members 11 and 12 are connected through an open lockbox 13 which has a gap between flanges 33 . The terms “inner” and “outer” are used to distinguish the members 11 and 12 , and their component parts, according to the members' respective positions at the open lockbox 13 . The inner member 11 is fitted generally within the inner surfaces of the open lockbox 13 and is captured by the flanges 33 . The outer member generally forms the outside surfaces of the open lockbox 13 .
[0052] The inner member 11 has an inner shank 14 , an inner jaw 16 , and an inner ring handle 20 . Similarly, the outer member 12 has an outer shank 15 , an outer jaw 17 , and an outer ring handle 21 . The ring handles, 20 and 21 , are designed for a surgeon to hold and manipulate the instrument 10 . The jaws, 16 and 17 , are designed to grasp tissue between the opposing seal surfaces 18 and 19 .
[0053] Each shank, 14 and 15 , has a respective ratchet stub 24 or 25 . Ratchet teeth, 26 and 27 , are designed to interlock in a manner that hold the members, 11 and 12 , in position. The shanks 14 and 15 are deflected in the manner of a cantilever spring when the jaws are forced together by the surgeon. The deflection of the shanks 14 and 15 produces a spring restoring force that can be opposed by interlocking the ratchet teeth, 26 and 27 .
[0054] The instrument 10 does not cause a short circuit when the ratchet teeth, 26 and 27 , are interlocked. This is accomplished by a suitable selection and placement of electrically insulating materials. In the preferred embodiment, the ratchet teeth 26 and 27 are composed of a polymeric material which is press-fit into the ratchet stubs 24 and 25 . A ratchet screw 28 is used in the preferred embodiment to secure the ratchet teeth 26 and 27 into the ratchet stubs 24 and 25 . During manufacture, the ratchet teeth 26 and 27 may be formed from a blank after the blank has been press fit into the ratchet stubs 24 and 25 .
[0055] In a second embodiment, one of the members, 11 or 12 , includes the ratchet stub and ratchet teeth as in integral part of the member, while the other member, 12 or 11 , has an insulative layer that prevents a short circuit between the members 11 and 12 when the ratchets are engaged.
[0056] The open lockbox 13 has the function of providing a pivoting joint for the members 11 and 12 . In addition, the flanges 33 provide lateral support to help maintain alignment of the jaws 16 and 17 . Closed lockbox designs are typically used in standard hemostat designs, wherein an inner member is completely captured through a slot in an outer member. The open lockbox 13 in present invention has a gap between the flanges 33 that is different from a closed lockbox design. The gap in the open lockbox 13 provides convenient access to install an electrically insulated pivot.
[0057] The electrically insulated pivot in the present invention comprises a shoulder washer 29 supporting a lockbox screw 30 . The shoulder washer 29 is composed of an electrically insulative material that prevents a short circuit between the members 11 and 12 . A large screw cap 31 fits over the head of the lockbox screw 30 . A small screw cap 32 fits over the threaded end of the lockbox screw 30 .
[0058] Each member 11 and 12 is connected to a pole of a bipolar electrosurgical generator. Electrical connectors 22 and 23 are located on the ring handles 20 and 21 to provide a convenient point of connection. The members 11 and 12 are formed of an electrically conductive material, such as stainless steel. The exposed surfaces of the members, except for the connectors 22 and 23 and the seal surfaces 18 and 19 , are preferably spray coated with an insulating material.
[0059] The characteristics of the bipolar electrosurgical current are determined by the design of the electrosurgical generator. In the preferred embodiment, the generator will have an output wherein the peak-to-peak voltage will not exceed 130 Volts. This is because higher voltages can cause sparking which results in localized burning of tissue which may result in a failure of the tissue weld. The preferred embodiment has the generator capable of producing high frequency output current of at least 2 Amps RMS. High electrical current is important because it heats the tissue sufficiently to melt the collagen. Lower electrical currents will often produce weak tissue welds with low bursting strength.
[0060] During operation, the instrument 10 is used to grasp tissue between the seal surfaces 18 and 19 . The surgeon squeezes the ring handles 20 and 21 together, causing pressure to be applied to the tissue. The ratchet teeth 26 and 27 are interlocked at the appropriate ratchet setting, depending on the tissue type and tissue thickness. Bipolar electrosurgical current is applied through the instrument and the tissue to cause the tissue to fuse.
[0061] The jaws 16 and 17 have a structure and cross-section that resist bending under load. Thus, for purposes of engineering analysis, the shank portions 14 and 15 act as a cantilever supported beam once the seal surfaces 18 and 19 have been mated. The length of this idealized cantilever beam extends from the lockbox screw 30 to the location of the respective ratchet subs 24 or 25 . It is possible to model each shank as a cantilever spring having a spring constant. Each ratchet position is designed to transmit a particular closure force to the jaws 16 and 17 against the action of the restoring force of the cantilever spring.
[0062] The spring constant is generally a function of Young's Modulus of the shank material, the moment of inertia of the shank, and the length of the shank portion 14 and 15 . When the jaws 16 and 17 of the instrument 10 are closed together, each shank 14 and 15 approximates a cantilever-supported beam. It is properly assumed that the deflection of each shank 14 and 15 remains within the linear range of its stress-strain curve. The behavior of such a beam is well known to materials engineers. A large spring constant will result in large closure forces between the seal surfaces 18 and 19 . Similarly, a small spring constant will result in a small closure forces between the seal surfaces 18 and 19 . The choice of a proper spring constant will depend on the length of the shank 14 or 15 and the distance between ratchet stops 26 and 27 .
[0063] Experimental results in animal studies suggest that the magnitude of pressure exerted on the tissue by the seal surfaces 18 and 19 is important in assuring a proper surgical outcome. Tissue pressures within a working range of about 3 kg/cm 2 to about 16 kg/cm 2 and, preferably, within a working range of 7 kg/cm 2 to 13 kg/cm 2 have been shown to be effective for sealing arteries and vascular bundles. Tissue pressures within the range of about 4 kg/cm 2 to about 6.5 kg/cm 2 have proven to be particularly effective in sealing arteries and tissue bundles.
[0064] It is desirable to tune the spring constant of the shank portions 14 and 15 , in conjunction with the placement of the ratchet teeth 26 and 27 , such that successive ratchet positions will yield pressures within the working range. In one embodiment, the successive ratchet positions are two millimeters apart.
[0065] Pressure on the tissue can be described in several ways. Engineers will recognize that the amount of pressure exerted on the tissue depends on the surface area of the tissue that is in contact with the seal surfaces. In the one embodiment, the width of each seal surface 18 and is in the range of 2 to 5 millimeters, and preferably 4 millimeters width, while the length of each seal surface 18 and 19 is preferably in the range of 10 to 30 millimeters. It has been found through experimentation that at least one interlocking ratchet position preferably holds the closure force between approximately 400 and 650 grams per millimeter of seal surface width. For example, if the width of the seal surface 18 and 19 is 4 millimeters, the closure force is preferably in the range of 1600 grams to 2600 grams. In one embodiment, the closure force is 525 grams per millimeter of width, yielding a closure force of 2100 grams for a 4 millimeter width seal surface 18 and 19 .
[0066] It has been found experimentally that local current concentrations can result in an uneven tissue effect, and to reduce the possibility of this outcome, each seal surface 18 and 19 has a radiused edge in the preferred embodiment. In addition, a tapered seal surface 18 and 19 has been shown to be advantageous in certain embodiments because the taper allows for a relatively constant pressure on the tissue along the length of the seal surfaces 18 and 19 . The width of the seal surfaces 18 and 19 is adjusted, in certain embodiments, wherein the closure force divided by the width is approximately constant along the length.
[0067] In one embodiment, a stop 37 , made from insulative material, is located in the instrument to maintain a minimum separation of at least about 0.03 millimeters between the seal surfaces 18 and 19 , as shown in FIG. 1. The stop 37 reduces the possibility of short circuits between the seal surfaces 18 and 19 . In another embodiment, the forceps instrument 10 includes a second or alternative stop 47 which is designed to maintain a minimum separation of at least about 0.03 millimeters between the seal surfaces 18 and 19 , as shown in FIG. 1. It is envisioned that the stop may be positioned proximate the lockbox 13 , proximate the lockbox screw 30 or adjacent the opposable seal surfaces 18 and 19 . Preferably, the stop 37 and/or the stop 47 maintain a separation distance within the range of about 0.03 millimeters to about 0.16 millimeters.
[0068] In certain embodiments, as shown in FIG. 11, the seal surfaces 18 and 19 comprise conductive regions 38 and insulative regions 39 arranged such that each conductive region 38 opposes an insulative region 39 when the opposable seal surfaces 18 and 19 are mated in opposition. The seal surfaces 18 and 19 , in certain embodiments, may be removable from its respective member 11 or 12 by standard mechanical interfaces, such as a pin and socket arrangement.
[0069] [0069]FIG. 2 shows an embodiment for a thirty-two millimeter curved seal surface. FIG. 3 is a side view of FIG. 2. The members 11 and 12 in FIG. 2 are formed from American Iron and Steel Institute (AISI) 410 stainless steel. The length and cross sectional area of the shank portions 14 and 15 are shown in FIGS. 2 and 3 to provide a spring constant of twenty-five pounds per inch deflection.
[0070] The embodiment shown in FIGS. 4 and 5 has a twenty millimeter curved seal surface. The embodiment shown in FIGS. 6 and 7 has a thirty-two millimeter straight seal surface. Each embodiment in FIGS. 2 through 7 is designed to have the look and feel of a standard hemostat.
[0071] [0071]FIGS. 8, 9 and 10 show three views of a shoulder pin 34 that can be used, in certain embodiments, instead of the lockbox screw 30 to connect the members 11 and 12 . The shoulder pin 34 has at least one ramp surface 35 that engages one of the members 11 or 12 to cause increasing mechanical interference as the jaws 16 and 17 move toward each other. In one embodiment, the shoulder pin 34 forms part of the open lockbox 13 to aid alignment of the seal surfaces 18 and 19 . In another embodiment, the shoulder pin 34 is used without an open-lockbox 13 , and movably pins the members 11 and 12 together without a flange 33 . The interference fit may require the calibration of the instrument 10 to insure that the applied force will be sufficient to provide the appropriate working pressure between the seal surfaces 18 and 19 . A slightly higher spring constant in the shank portions 14 and 15 is preferably used, depending on the level of interference caused by the shoulder pin.
[0072] A method of using the bipolar electrosurgical instrument comprises the following steps. A surgeon grasps the ring handles 20 and 21 on the instrument 10 to manipulate the jaws 16 and 17 . A vessel or vascular tissue is compressed between the opposable seal surfaces 18 and 19 . The opposable seal surfaces 18 and 19 preferably come together in aligned opposition due to the alignment action of the open-lockbox 13 , or in certain embodiments due to the alignment action of the shoulder pin 34 . The surgeon further deflects the shank portions 14 and 15 of the members 11 and 12 to engage the ratchet teeth 26 and 27 . The engagement of the ratchet teeth 26 and 27 hold the shank portions 14 and 15 in their deflected positions to provide a constant spring force that is transmitted as a closure force to the jaws 16 and 17 . An electrosurgical generator is connected to the instrument 10 through connectors 22 and 23 on the ring handles 20 and 21 . An electrical switch is used to close a circuit between the generator and the instrument 10 . The switch may be a footswitch such as Valleylab's catalog number E6009, available from Valleylab Inc., Boulder Colo. The electrosurgical current flows through an electrically conductive path on each of the inner and outer members 11 and 12 between its respective electrical connector, 22 or 23 , and its respective seal surface, 18 or 19 . An electrically insulative coating 36 substantially covers each member 11 and 12 to protect the surgeon against electrical arcs. An insulative sheath may also be used to cover the members or the component parts thereof, i.e., handles 20 , 21 , shanks 14 and 15 and the outer surfaces (non-opposing surfaces) of the jaw members 16 , 17 .
[0073] It is envisioned that the outer surface of the jaw members 16 and 17 may include a nickel-based material, coating, stamping, metal injection molding which is designed to reduce adhesion between the jaw members (or components thereof) with the surrounding tissue during activation and sealing. Moreover, it is also contemplated that other components such as the shanks 14 , 15 and the ring handles 20 , 21 may also be coated with the same or a different “non-stick” material. Preferably, the non-stick materials are of a class of materials that provide a smooth surface to prevent mechanical tooth adhesions.
[0074] It is also contemplated that the tissue sealing surfaces 18 and 19 of the jaw members 16 and 17 , respectively, may be manufactured from one (or a combination of one or more) of the following “non-stick” materials: nickel-chrome, chromium nitride, MedCoat 2000 manufactured by The Electrolizing Corporation of OHIO, Inconel 600 and tin-nickel. For example, high nickel chrome alloys and Ni200, Ni201 (˜100% Ni) may be made into electrodes or sealing surfaces by metal injection molding, stamping, machining or any like process.
[0075] In addition these materials preferably include an optimal surface energy for eliminating sticking due in part to surface texture and susceptibility to surface breakdown due electrical effects and corrosion in the presence of biologic tissues. It is envisioned that these materials exhibit superior non-stick qualities over stainless steel and should be utilized on the instrument in areas where the exposure to pressure and RF energy can create localized “hot spots” more susceptible to tissue adhesion. As can be appreciated, reducing the amount that the tissue “sticks” during sealing improves the overall efficacy of the instrument.
[0076] The tissue sealing surfaces 18 and 19 may also be “coated” with one or more of the above materials to achieve the same result, i.e., a “non-stick surface”. For example, Nitride coatings (or one or more of the other above-identified materials) may be deposited as a coating on another base material (metal or nonmetal) using a vapor deposition manufacturing technique.
[0077] One particular class of materials disclosed herein has demonstrated superior non-stick properties and, in some instances, superior seal quality. For example, nitride coatings which include, but not are not limited to: TiN, ZrN, TiAIN, and CrN are preferred materials used for non-stick purposes. CrN has been found to be particularly useful for non-stick purposes due to its overall surface properties and performance. Other classes of materials have also been found to reducing overall sticking. For example, high nickel/chrome alloys with a Ni/Cr ratio of approximately 5:1 have been found to significantly reduce sticking in bipolar instrumentation. One particularly useful non-stick material in this class is Inconel 600 . Bipolar instrumentation having electrodes made from or coated with Ni200, Ni201 (˜100% Ni) also showed improved non-stick performance over typical bipolar stainless steel electrodes.
[0078] It is to be understood that the above described embodiments are only illustrative of the application of the principles of the present invention. Numerous modifications and alternative arrangements may be devised by those skilled in the art without departing from the spirit and scope of the present invention. The appended claims are intended to cover such modifications and arrangements. | A bipolar electrosurgical instrument has opposable seal surfaces on its jaws for grasping and sealing vessels and vascular tissue. Inner and outer instrument members allow arcuate motion of the seal surfaces. An open lockbox provides a pivot with lateral support to maintain alignment of the lateral surfaces. Ratchets on the instrument members hold a constant closure force on the tissue during the seal process. A shank portion on each member is tuned to provide an appropriate spring force to hold the seal surfaces together. During surgery, the instrument can be used to grasp and clamp vascular tissue and apply bipolar electrosurgical current through the clamped tissue. In one embodiment, the seal surfaces are partially insulated to prevent a short circuit when the instrument jaws are closed together. In another embodiment, the seal surfaces are removably mounted on the jaws. | 0 |
BACKGROUND OF THE INVENTION
[0001] This invention relates generally to fabricating a fiber-reinforced article and particularly to fabricating the article by a vacuum assisted molding process using membrane.
[0002] Composite articles made from a fiber-reinforced resin matrix that are to be used at relatively elevated temperatures are known. By way of example, such composite articles can include jet engine blades, jet engine nacelles, boat hulls, car bodies and components, wind turbine blades, aircraft structures such as wings, wing parts, radar domes, fuselage components, nose cones, flap tracks, landing gear and rear bulkhead. The reinforcing fibers used in the composite article may be any suitable technical fiber such as fiberglass, carbon, aramid, ceramic, hybrid and the like. Depending on the service that the composite article is going to be put into, the article may be manufactured with a resin applied at an elevated temperature so the surface tension of the resin is relatively low.
[0003] The known composite articles may be fabricated by infusing resin into a fiber-reinforced layer with vacuum. Laminated sheet material is placed adjacent the fiber-reinforced layer. The laminated sheet material includes a membrane. It is known that the resin is introduced to the fiber-reinforced layer at relatively high temperatures so that the resin has a relatively low surface tension. The resin can, at times, wet or leak through the membrane. When wetting or leaking occurs the molding process is rendered less effective.
[0004] Therefore, a need exists for an improved membrane structure that can better resist wetting or leaking through the membrane for use in vacuum assisted molding operations with resins at a relatively high temperature and/or that have relatively low surface tensions.
BRIEF DESCRIPTION OF THE INVENTION
[0005] One aspect of the invention is a method of manufacturing a fiber-reinforced article. The method includes the steps of providing a mat fiber structure defining voids therein. A membrane structure is applied over at least a portion of the mat fiber structure. The membrane structure includes a microporous membrane. At least the microporous membrane of the membrane structure has an oil resistance rating of at least a number 8 determined by AATCC 118 testing. A resin and hardener mix is provided. The resin is infused into voids of the mat fiber structure by applying a vacuum to the mat fiber structure and the membrane structure wherein the membrane structure inhibits the flow of resin therethrough.
[0006] Another aspect of the invention is a method of manufacturing a fiber reinforced article. The method includes the steps of providing mat fiber structure defining voids therein. A membrane structure is applied over the mat fiber structure. The membrane structure has an oil resistance rating of at least a number 8 determined by AATCC 118 testing and an air permeability of at least 0.005 CFM per square foot at 125 Pascals as determined by ASTM D737 testing. A resin and hardener mix is provided. The resin is infused into voids of the mat fiber structure by applying a vacuum to the mat fiber structure and the membrane structure wherein the membrane structure inhibits the flow of resin therethrough.
[0007] Another aspect of the invention is a membrane structure for use in a transfer molding operation in which a resin and hardener mix is used. The membrane structure includes a microporous membrane. A porous fabric is laminated to the microporous membrane. A treatment material is applied to at least the macroporous membrane. The microporous membrane has an oil resistance of at least a number 8 determined by AATCC 118 testing and having an air permeability of at least 0.005 CFM per square foot determined by ASTM D737 testing.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] These and other features, aspects, and advantages of the invention will be better understood when the following detailed description is read with reference to the accompanying drawings, in which:
[0009] FIG. 1 is a perspective view illustrating a composite article made with fiber-reinforcement according to one aspect of the invention;
[0010] FIG. 2 is an exploded perspective view illustrating the manufacture of a portion of the composite article shown in FIG. 1 , according to the one aspect;
[0011] FIG. 3 is an enlarged cross-sectional view of a membrane structure illustrated in FIG. 2 used in the manufacture of at least a the portion of the composite article, according to the one aspect;
[0012] FIG. 4 is a view similar to FIG. 3 illustrating a membrane structure according to another aspect of the invention;
[0013] FIG. 5 is a view similar to FIG. 3 illustrating a membrane structure according to another aspect of the invention; and
[0014] FIG. 6 is a view similar to FIG. 3 illustrating a membrane structure according to yet another aspect of the invention.
DETAILED DESCRIPTION OF THE INVENTION
[0015] A method of fabricating a composite article made with a fiber-reinforced resin matrix utilizing a new and improved oleophobic microporous membrane structure is described below in detail. The new and improved oleophobic microporous membrane structure resists, to an extent that is heretofore unknown, the leaking, “wetting” or the passage of resin with relatively low surface tensions while permitting gas to pass through it. The membrane structure permits a vacuum to be applied relatively evenly to the entire composite article or desired select portions of the composite article during a molding process. The membrane structure also enables the use of resin at operating conditions so the resin has relatively low surface tensions. The membrane structure further facilitates a controlled flow of resin and reduces defects in the article that could result from uneven resin flow. Production cycle time along with labor time is reduced along with a reduction in the cost of process consumable materials. The use of the new and improved oleophobic microporous membrane structure provides, for example, improved quality of the finished part, lower void content, reduced manual rework and optimized fiber to resin ratios.
[0016] Composite articles made from a fiber-reinforced resin matrix may include, by way of a non-limiting example, an article 20 , such as a carbon reinforced nacelle or housing for an aircraft jet engine 22 , as illustrated in FIG. 1 . The article 20 or nacelle is positioned about the jet engine 22 . Because of its proximity to the jet engine 22 , at least portions of the article 20 or nacelle may be exposed to elevated temperatures (for example 180° C.) for extended durations as during operation of the jet engine. While a jet engine nacelle is disclosed and described, the article 20 can include, without limitation, jet engine blades, jet engine nacelles, boat hulls, car bodies and components, wind turbine blades, aircraft structures such as wings, wing parts, radar domes, fuselage components, nose cones, flap tracks, landing gear and rear bulkhead.
[0017] The application for the article 20 may require relatively high strength over the time exposed to elevated temperatures or relatively low weight for which a technical fiber is used, such as fiberglass, carbon, aramid, ceramic, hybrid and the like or mixtures thereof. The article 20 may be manufactured with a vacuum assisted molding process when relatively high dimensional tolerance is required, low void content or high reinforcing fiber content is desired. Vacuum assisted molding processes often apply a resin, or resin and hardener mix, at a relatively elevated temperature so its surface tension is relatively low.
[0018] The article 20 , according to one aspect of the invention, is made from a carbon fiber reinforced resin matrix structure. The carbon fiber reinforced structure of the article 20 can be made from one or more layers of carbon fiber reinforced material. The article 20 is fabricated by infusing resin, with or without hardener, into the carbon fiber reinforced structure with vacuum. The resin is introduced to the carbon fiber reinforcing structure at a relatively high temperature so that the resin has a relatively low surface tension.
[0019] The article 20 may be made from a pair of parts. The parts of the article 20 are made separately. The parts of the article 20 are then attached together by suitable means to form the finished article 20 , as illustrated in FIG. 1 .
[0020] Referring to FIG. 2 , each part of the article 20 may include a core 40 . The core 40 typically includes a plurality of grooves to facilitate the flow of resin through core and the remainder of the article 20 during manufacture. The core 40 may be made from any suitable material, such as polymeric foam, wood, and/or a metal honeycomb. Examples of suitable polymeric foams include, but are not limited to, PVC foams, polyolefin foams, epoxy foams, polyurethane foams, polyisocyanurate foams, and mixtures thereof.
[0021] The article 20 also includes at least one layer of structural reinforcing material 42 located adjacent the core 40 . Each layer of the structural reinforcing material 42 is formed from a mat of reinforcing fibers. Typically, the mat is a woven mat of reinforcing fibers or a non-woven mat of directionally oriented reinforcing fibers. The mat of reinforcing fibers has voids throughout the structural reinforcing material 42 that are to be completely filled with resin. Examples of suitable reinforcing fibers include, but are not limited to, glass fibers, graphite fibers, carbon fibers, polymeric fibers, ceramic fibers, aramid fibers, kenaf fibers, jute fibers, flax fibers, hemp fibers, cellulosic fibers, sisal fibers, coir fibers and, hybrid fibers and the like or mixtures thereof.
[0022] During manufacture, a resin, which may also be a resin and hardener mix, is infused into the structural reinforcing material 42 of the article 20 to fill the voids in the mat of reinforcing fibers and then cured. The infused resin may be cured with heat and/or time in order to provide the article 20 . The infused resin may be cured with heat and/or time in order to provide the article 20 . The cured resin provides integrity and strength to each finished article 20 . Examples of suitable resins include, but are not limited to, vinyl ester resins, epoxy resins, polyester resins, diglycidyl ether of bishpenol-A based resins, and mixtures thereof. The choice of a resin may depend upon the intended service of the article 20 , the reinforcing fiber used and the manufacturing process.
[0023] One particularly suitable resin and hardener mix is commercially available under the tradename RTM-6 from Hexcel Corporation. The resin is a monocomponent material having a crosslinker or hardener mixed with the resin. An example of a suitable crosslinker is a blend of cycloaliphatic amines. When cured, the resin displays a three-dimensional structural network with stable properties at the relatively high temperature it may be exposed to.
[0024] The resin and hardener mix has a relatively low surface tension at the elevated temperature it is typically infused into the reinforcing fiber mat, as illustrated in the graph below. For example, if applied at 100° C., the surface tension of the resin and hardener mix is in the range of about 21 to 22 dynes/cm. At 80° C. the surface tension of the resin and hardener mix is in the range of about 23 to 24 dynes/cm. Approaching 180° C. the estimated surface tension of the resin and hardener mix is about 13 dynes/cm. The resin and hardener mix with this relatively low surface tension can leak through, or “wet”, heretofore known membrane structures that have been used in vacuum assisted resin transfer molding processes.
[0025] During manufacture of the article 20 , the structural reinforcing material 42 is arranged relative to the core 40 , if any is used, and then positioned in a mold 60 . A release material 80 is applied to the exposed or outer surface of the structural reinforcing material 42 of the article 20 . The release material 80 is in the form of a release film and peel ply. An oleophobic and gas-permeable membrane structure or membrane assembly 82 is then applied over the release material 80 and the article 20 to facilitate the resin infusion process.
[0026] An air transport material 84 may be positioned over membrane structure or assembly 82 to further assist in degassing the work-piece by permitting gas displaced during the infusion of resin to escape the voids in the structural reinforcing material 42 . Air transport material 84 can be formed from any suitable mesh or fabric material, for example, a polyethylene mesh.
[0027] A gas-impermeable vacuum bagging film or vacuum film 86 formed from a suitable material, for example, a polyamid, is positioned over air transport material 84 . A vacuum connection 100 extends through a lateral edge of the vacuum bagging film 86 . A seal 102 extends around the periphery of the mold 60 between the mold and vacuum bagging film 86 to prevent leakage of gas and resin. The seal 102 is in fluid connection with the vacuum connection 100 .
[0028] A resin infusion input connection 104 extends through a central portion of the vacuum bagging film 86 . The resin infusion connection 104 is in fluid connection with a resin supply tube 106 running essentially for the extent of the mold 60 . The resin supply tube 106 is positioned adjacent the article 20 .
[0029] The resin is introduced into the resin infusion connection 104 , the resin supply tube 106 and structural reinforcing materials 42 while a vacuum is established through vacuum connection 100 . The vacuum facilitates resin flow and infuses the resin into the voids in the structural reinforcing material 42 . Membrane assembly 82 prevents the resin from flowing away from structural reinforcing materials 42 while permitting gas displaced by the infused resin to escape to the vacuum connection 100 . The supply of resin and vacuum to the article 20 is stopped. The resin is then cured. Resin input connection 104 and supply tube 106 , air transport material 84 , vacuum bagging film 86 , membrane assembly 82 and release material 80 are removed from the article 20 . The article 20 can then be removed from the mold 60 and permitted to further cure, be used, finished or assembled with other components.
[0030] In one aspect of the invention, the membrane assembly 82 ( FIG. 3 ) includes a microporous membrane 120 thermally or adhesively laminated to a porous fabric backing material 122 . The membrane assembly 82 has a membrane side 124 and a fabric backing side 126 .
[0031] The membrane 120 is preferably a microporous polymeric membrane that allows the flow of gases, such as air or water vapor, into or through the membrane and is hydrophobic. The membrane 120 is formed from any suitable material, for example, polytetrafluoroethylene, polyolefin, polyamide, polyester, polysulfone, polyether, acrylic and methacrylic polymers, polystyrene, polyurethane, polypropylene, polyethylene, polyphenelene sulfone, and mixtures thereof. A preferred microporous polymeric membrane for use as the membrane 120 is an expanded polytetrafluoroethylene (ePTFE) that has preferably been at least partially sintered.
[0032] An ePTFE membrane typically comprises a plurality of nodes interconnected by fibrils to form a microporous lattice type of structure, as is known. The membrane 120 has an average pore size of about 0.01 micrometer (μ) to about 10μ. Surfaces of the nodes and fibrils define numerous interconnecting pores that extend completely through the membrane 120 between the opposite major side surfaces of the membrane in a tortuous path. Typically, the porosity (i.e., the percentage of open space in the volume of the membrane 120 ) of the membrane 120 is between about 50% and about 98%. The material, average pore size and surface energy of the membrane 120 help establish the oleophobicity of the membrane.
[0033] The membrane 120 is preferably made by extruding a mixture of polytetrafluoroethylene (PTFE) fine powder particles (available from DuPont under the name TEFLON® fine powder resin) and lubricant. The extrudate is then calendered. The calendered extrudate is then “expanded” or stretched in at least one direction and preferably two orthogonal directions, to form the fibrils connecting the nodes in a three-dimensional matrix or lattice type of structure. “Expanded” is intended to mean sufficiently stretched beyond the elastic limit of the material to introduce permanent set or elongation to the fibrils. The membrane 120 is preferably then heated or “sintered” to reduce and minimize residual stress in the membrane material. However, the membrane 120 may be unsintered or partially sintered as is appropriate for the contemplated use of the membrane. An example of suitable membrane 120 properties includes a unit weight of about 0.42 ounce per square yard, an air permeability of about 1.5 CFM, a Mullen Water Entry pressure of about 15 PSI and a moisture vapor transmission rate (MVTR) of about 60,000 grams per square meter per day (gr/m 2 /day).
[0034] It is known that porous ePTFE membrane 120 , while having excellent hydrophobic properties, is oleophilic. That is, the material making up the membrane 120 is susceptible to not holding out challenge agents, such as resin and hardener mix at relatively elevated temperature so it has a relatively low surface tension, such as 24 dynes/cm or lower.
[0035] Other materials and methods can be used to form a suitable membrane 120 that has an open pore structure. For example, other suitable materials that may be used to form a porous membrane include, but are not limited to, polyolefin, polyamide, polyester, polysulfone, polyether, acrylic and methacrylic polymers, polystyrene, polyurethane, polypropylene, polyethylene, cellulosic polymer and combinations thereof. Other suitable methods of making a microporous membrane 120 include foaming, skiving, casting or laying up fibers or nano-fibers of any of the suitable materials.
[0036] According to one aspect of the invention, at least the membrane 120 of the membrane assembly 82 is treated with an oleophobic fluoropolymer material in such a way that enhanced oleophobic properties result without compromising its gas permeability. According to one non-limiting aspect, the entire membrane assembly 82 is preferably treated with the oleophobic fluoropolymer material. The oleophobic fluoropolymer coating adheres to the nodes and fibrils that define the pores in the membrane 120 and the surfaces of the pores in the fabric backing material 122 .
[0037] Substantially improved oleophobic properties of at least the microporous membrane 120 can be realized if the surfaces defining the pores in the membrane 120 are treated with the oleophobic fluoropolymer material. The treatment may be applied by to the membrane 120 , the backing material 122 or the membrane assembly 82 any suitable means, such as those disclosed and described in U.S. Pat. No. 6,228,477 or U.S. Patent Application Publication 2004/0059717. The increased oleophobic property of the membrane 120 , backing material 122 or the membrane assembly 82 is important as resins and hardener mixes that are being used that have relatively low surface tensions.
[0038] The term “oleophobic” is used to describe a material property that is resistant to wetting by liquid challenge materials, such as resin. An “oleophobic property” or “oleophobicity” of the membrane assembly 82 is typically rated on a scale of 1 to 8 according to AATCC test 118. This test objectively evaluates a test specimen's resistance to wetting by various standardized challenge liquids having different surface tensions. Eight standard challenge liquids, labeled #1 to #8, are used in the test. The #1 challenge liquid is mineral oil (surface tension: 31.5 dynes/cm at 25° C.) and the #8 challenge liquid is heptane (surface tension: 19.61 dynes/cm at 25° C.). According to the test method, five drops of each challenge liquid are placed on one side of the membrane assembly 82 to be tested. Failure occurs when leaking or wetting of the membrane assembly 82 by a selected challenge liquid occurs within 30 seconds.
[0039] The oleophobic rating number of the membrane assembly 82 corresponds to the last challenge liquid successfully tested. The higher the oleophobic number rating, the greater the oleophobic property, or oleophobicity, as evidenced by resistance to penetration by challenge liquids of relatively lower surface tension. It was found that both the membrane side 124 and the fabric side 126 of the membrane assembly 82 were able to pass a challenge by hexane that has a relatively lower surface tension than heptane. See the table below for the relation of surface tension and temperature of challenge agents.
[0000]
Surface tension in dynes/cm at ° C.
Oil repellency
grade
Challenge
number
liquid
20
25
40
50
60
70
80
90
100
0
none
1
Kaydol
31.5
2
65 v % Kaydol:
28
35 v % n-
hexadecane
3
n-hexadecane
27.50
27.07
25.79
24.94
24.08
23.23
22.38
21.52
20.67
4
n-tetradecane
26.60
26.17
24.86
23.99
23.12
22.26
21.39
20.52
19.65
5
n-dodecane
25.40
24.96
23.63
22.75
21.86
20.98
20.10
19.21
18.33
6
n-decane
23.80
23.34
21.96
21.04
20.12
19.20
18.28
17.36
16.44
7
n-octane
21.60
21.12
19.70
18.75
17.80
16.85
15.89
14.94
13.99
8
n-heptane
20.10
19.61
18.14
17.16
16.18
15.20
14.22
13.24
12.26
8+
n-hexane
18.40
18.35
[0040] Therefore, a new non-standard rating number of “8+” was adopted to indicate that a tested specimen resisted penetration of hexane under standard test conditions. Thus, the term “preferably at least a number 8 rating” means that a standard number 8 rating or more, such as 8+, is achieved by the tested specimen. This is a significant improvement over known membrane assemblies used in vacuum assisted molding processes.
[0041] Sample laminates in the form of membrane assemblies 82 were treated according to one aspect of the invention. The properties that resulted from the treatment are reported in the table below.
[0000]
Oil Hold Out
Membrane
Fabric
Air Perm
Side
Side
(CFM)
8+
8+
0.1
[0042] Some membranes 120 are relatively thin and fragile. The fabric backing material 122 is included in the membrane assembly 82 to provide support to the membrane 120 . The backing material 122 may have other or alternative functions including, for example, restricting or preventing the flow of the same and/or different particles and fluids as the membrane 120 and/or protecting the membrane 120 or other layers in the membrane assembly 82 from damage from handling.
[0043] The fabric backing material 122 may be formed from non-woven or woven polymeric fibers, for example, polyester fibers, nylon fibers, polyethylene fibers and mixtures thereof. The backing material 122 is typically made from a porous woven, non-woven or scrim of polymeric material. Often the backing material 122 is made using a fibrous material, however, other porous materials may also be used. The average pore size of the backing material 122 is usually larger than the average pore size of the membrane 120 , although this is not necessary in some applications. Thus, in some applications, the backing material 122 acts to at least partially filter the fluid flowing into or through the laminated article. Typically, the average pore size of the support fabric is about 500 μm (micron) or less and often at least about 0.5 μm. The porosity of the support fabric is often in the range of about 20% to almost 90%.
[0044] Suitable polymeric materials for the porous backing material 122 include, for example, stretched or sintered plastics, such as polyesters, polypropylene, polyethylene, and polyamides (e.g., nylon). These materials are often available in various weights including, for example, 0.5 oz/yd 2 (about 17 gr/m 2 ), 1 oz/yd 2 (about 34 gr/m 2 ), and 2 oz/yd 2 (about 68 gr/m 2 ). Woven fabric such as 70 denier nylon woven taffeta pure finish may also be used. Another suitable fabric is a non-woven textile such as a 1.8 oz/yd 2 co-polyester flat-bonded bi-component non-woven media.
[0045] The membrane assembly 82 is gas permeable and oleophobic. That is, the membrane assembly 82 permits the passage of gases through it. The addition of the oleophobic treatment increases the resistance of the membrane assembly 82 to being wet by resin, oil or oily substances. The membrane assembly 82 has an oil hold out or resistance rating of at least a number 8 as determined by AATCC 118 testing. The membrane assembly 82 also has an air permeability of at least 0.01 CFM/ft 2 at 125 Pascals per square foot of membrane measured by ASTM D737 testing.
[0046] The resulting membrane assembly 82 , according to the aspect illustrated in FIG. 3 , has a membrane side 124 and a fabric side 126 . The membrane assembly 82 is hydrophobic on both the membrane side 124 and the fabric side 126 . That is, the membrane assembly 82 prevents or resists the passage of liquids, such as water, through the laminated article. The membrane assembly 82 is gas permeable and moisture vapor transmissive. That is, the membrane assembly 82 permits the passage of gases, such as air, carbon dioxide and water vapor, through it.
[0047] An oleophobic treatment is applied to the entire membrane assembly 82 from an inorganic solvent, according to one aspect of the invention, to provide improved oleophobicity to the entire membrane assembly. The addition of the oleophobic treatment increases the resistance of the membrane assembly 82 to the passage of the resin from either the membrane side 124 or the fabric side 126 . It will be apparent, however, that just the membrane 120 may be treated to increase its oleophobicity.
[0048] The backing material 122 and the membrane 120 are laminated together. The lamination of the hacking material 122 and the membrane 120 can be accomplished by a variety of methods, such as thermal lamination or adhesive lamination. FIG. 3 illustrates one aspect of a membrane assembly 82 in which the backing material 122 and membrane 120 are adhered by thermal lamination. The membrane 120 is preferably a microporous expanded polytetrafluoroethylene (ePTFE) membrane available from BHA Group, Inc. as part number QM902. The fabric backing material 122 is preferably a porous layer of spunbond material available from Freudenberg as part number Novatexx 2425. The membrane 120 and fabric backing material 122 are laminated together. The laminated membrane assembly 82 is then treated to increase oleophobic properties, according to one aspect.
[0049] It has been found that an inorganic fluid under supercritical conditions can dissolve the preferred fluorinated polymer treatment material. The resulting solution is capable of wetting the membrane assembly 82 and entering pores in the microporous membrane 120 with the dissolved fluorinated polymer treatment material. The solution with dissolved fluorinated polymer treatment material has a surface tension, viscosity and relative contact angle that permit the dissolved treatment material to be easily carried into the smallest pores of the membrane 120 and the backing material 122 with the inorganic solvent.
[0050] The inorganic solvent is preferably carbon dioxide in a supercritical phase. The surface tension of the supercritical carbon dioxide (SCCO 2 ) solution is less than 1 dyne/cm and most preferably less than 0.1 dyne/cm so it can enter very small areas of the membrane assembly 82 to be treated, such as the pores of the membrane 120 . Supercritical carbon dioxide also has a viscosity of less than about 0.1 centipoise. The viscosity and surface tension of the solution are extremely low so very little resistance to flow is encountered, thus, lending itself to the possibility of entering even the smallest pores of the membrane 120 . Effective treatment is possible even if the membrane assembly 82 is in a confined state, such as in a tightly wound roll of sheet material.
[0051] The fluorinated polymer treatment material, or fluoropolymer, is deposited on and around surfaces of the nodes and fibrils that define the interconnecting pores extending through the membrane 120 and pores of the backing material 122 . This results in a relatively thin and even coating being applied to virtually all the surfaces of the membrane assembly 82 . Once a predetermined proper amount of fluorinated polymer treatment material is deposited on the membrane assembly 82 the pores are not dramatically reduced in flow area from that of an untreated laminated article. Improved oleophobic properties are realized on both the membrane side 124 and the fabric side 126 of the membrane assembly 82 .
[0052] Examples of suitable fluorinated polymer treatment materials include those having a fluoroalkyl portion or, preferably, a perfluoroalkyl portion. One such fluorinated polymer treatment material is a perfluorakyl acrylic copolymer refereed to as Fabati 100 and was designed and synthesized by Micell Technologies, Inc. Fabati 100 was synthesized in MIBK (methyl isobutyl ketone) utilizing TAN (1,1,2,2,-tetrahydroperfluorooctyl acrylate); butyl acrylate; a cross-linking agent TMI (isopropenyl-a,a-dimethylbenzyl isocyanate); Vazo 52 initiator (2,4-dimethyl-2,2′-azobispentanenitrile). The Fabati 100 treatment material is cross-linked by a post-treatment cure with heat. Another suitable perfluorakyl acrylic copolymer is Fabati 200. Fabati 200 is similar to Fabati 100 but does not have the cross-linking agent (TMI) and HBA (4-hydroxybbutyl acrylate) is used instead of butyl acrylate. Thus, the Fabati 200 treatment material does not require post-treatment heating.
[0053] A variety of inorganic solvents can be used in the solution containing the oleophobic fluorinated polymer treatment material. The term “inorganic solvent” refers to non-aqueous solvents and combinations of non-aqueous solvents, and, in particular, to solvents comprising inorganic compounds. Suitable inorganic solvents include, for example, carbon dioxide (CO2), ammonia (NH 3 ), urea [(NH 2 ) 2 CO], inorganic acids, such as hydrochloric acid, sulfuric acid, carbon tetrachloride and carbon tetrafluoride and oxides of carbon such as carbon dioxide (CO 2 ), carbon monoxide (CO), potassium carbonate and sodium bicarbonate. A choice of solvent or solvents may be affected by a variety of factors including solubility of the treatment material in the solvent, molecular weight of the solvent and polarity of the solvent. In preferred aspects of the invention, the treatment material is completely dissolved in the inorganic solvent. In other aspects of the invention, the treatment material is not fully dissolved in the inorganic solvent.
[0054] The amount of fluorinated polymer treatment material in the solution may vary over a wide range. Typically, the amount of fluorinated polymer treatment material in the solution affects the resultant oleophobicity of the membrane assembly 82 . Typically, the amount of fluorinated polymer treatment material, or fluoropolymer, in the solution is about 25 wt % or less and preferably, about 10 wt % or less. For many applications, that the membrane assembly 82 is used in, the amount of fluoropolymer treatment material in the inorganic solvent ranges from about 0.8 wt % to about 10.0 wt % and preferably, from about 2.0 wt % to about 5.0 wt %.
[0055] According to one aspect of the invention, the backing material 122 and membrane 120 of the membrane assembly 82 are treated together subsequent to lamination of the backing material 122 and membrane 120 . Typically, during treatment, the fluorinated polymer solution wets and, preferably, saturates, the backing material 122 and membrane 120 of the membrane assembly 82 . The use of an inorganic solvent facilitates the relatively uniform distribution of the fluorinated polymer treatment material throughout the backing material 122 and membrane 120 of the laminated article. The inorganic solvent is then removed. The fluorinated polymer treatment material attaches to the backing material 122 and membrane 120 and enhances the oleophobicity at both sides 124 , 126 of the membrane assembly 82 .
[0056] Optionally, the treated membrane assembly 82 may then be “cured” by heating. The “curing” process increases the oleophobicity by allowing rearrangement of the fluoropolymer into an oleophobic orientation. The curing temperature varies among fluoropolymers.
[0057] The membrane assembly 82 has a relatively high moisture vapor transmission rate (MVTR) and air permeability while its oleophobic properties are improved by the treatment material. Both sides 124 , 126 of the membrane assembly 82 have an oil hold out rating of at least a number 8 rating as determined by AATCC 118 testing and preferably at least a number 8+ rating. The membrane assembly 82 preferably has a moisture vapor transmission rate (MVTR) of at least 1500 gr/m 2 /day and more preferably at least 15,000 g/m 2 /day measured by JISL-1099B2 testing. The membrane assembly 82 preferably has an air-permeability of at least 0.005 CFM per square foot of membrane, preferably at least 0.01 CFM per square foot of membrane and more preferably at least 0.05 CFM per square foot of membrane measured by ASTM D737 testing.
[0058] Improved oleophobic properties of the membrane assembly 82 are realized according to one aspect of the invention by treating surfaces defining the pores in the membrane 120 and backing material 122 as well as the surfaces of the membrane side 124 and the fabric side 126 of the membrane assembly 82 with a fluorinated polymer treatment material, or fluoropolymer. The membrane assembly 82 , according to one aspect of the invention, has the treatment material coating even the smallest pores of the membrane 120 of the laminated article. The applied treatment material modifies properties of the entire membrane assembly 82 , such as oleophobicity.
[0059] An alternate aspect of the invention is to use two or more membrane assemblies 82 physically overlaid together instead of being laminated together. In testing, a sample membrane structure included three membrane assemblies 82 overlaid together. The resultant membrane structure resisted leaking and wetting with the RTM-6 resin and hardener mix until the temperature of the resin and hardener mix reached 180° C. The surface tension at 180° C. for the RTM-6 resin and hardener mix is about 13 dynes/cm. In terms of AATCC 118 testing, the membrane assembly 82 has a hold out rating of at least a number 8 and even a number 8+. Air permeability of this membrane structure was 0.1 CFM at 125 Pascal per square foot of membrane measured by ASTM D737 testing.
[0060] A membrane assembly 82 a , according to another aspect of the invention illustrated in FIG. 4 , includes two membrane assemblies 82 as illustrated in FIG. 3 laminated together and then subjected to the oleophobic treatment. The membrane assembly 82 a has a membrane side 124 and a fabric side 126 . The membrane assembly 82 a is hydrophobic on both the membrane side 124 and the fabric side 126 . That is, the membrane assembly 82 a prevents or resists the passage of liquids, such as water, through the laminated article. The membrane assembly 82 a is gas permeable and moisture vapor transmissive. That is, the membrane assembly 82 a permits the passage of gases, such as air, carbon dioxide and water vapor, through it.
[0061] The membrane assembly 82 a is oleophobic. The addition of the oleophobic treatment increases the resistance of the membrane assembly 82 a to leakage or being wet by liquid resin, oil or oily substances. The membrane assembly 82 a has an oil hold out or resistance rating of at least a number 8 as determined by AATCC 118 testing and preferably at least a number 8+ rating. The membrane assembly 82 a also has an air permeability of at least 0.01 CFM/ft 2 at 125 Pascal as determined by ASTM D737 testing.
[0062] The membrane assembly 82 b, according to another aspect illustrated in FIG. 5 , includes two membrane assemblies laminated together. The membrane assembly 82 b is similar to membrane assembly 82 a. However, the membranes 140 used have an oleophobic treatment applied differently than the membranes 120 . The membranes 140 are treated by the method disclosed in U.S. Pat. No. 6,288,477. The treated membranes 140 are then laminated to untreated fabric backing material to form the membrane assembly 82 b. The membrane assembly 82 b has a membrane side 144 and a fabric side 126 . The membrane assembly 82 b is hydrophobic on both the membrane side 144 and the fabric side 126 . That is, the membrane assembly 82 b prevents or resists the passage of liquids, such as water, through the laminated article. The membrane assembly 82 b is gas permeable and moisture vapor transmissive. That is, the membrane assembly 82 b permits the passage of gases, such as air, carbon dioxide and water vapor, through it.
[0063] The membrane assembly 82 b is oleophobic. The addition of the oleophobic treatment increases the resistance of the membrane assembly 82 b to being leakage or by resin, oil or oily substances. The membrane assembly 82 b has an oil hold out or resistance rating of at least a number 8 as determined by AATCC 118 testing and preferably at least a number 8+ rating. The membrane assembly 82 b also has an air permeability of at least 0.01 CFM/ft 2 at 125 Pascal per square foot of membrane measured by ASTM D737 testing.
[0064] The membrane assembly 82 c, according to yet another aspect illustrated in FIG. 6 , includes two membranes 120 and 160 laminated to the backing material 122 . The membranes 120 and 160 may be laminated together or integrally formed as one piece during manufacturing. The membranes 120 , 160 may be identical or have different thicknesses, pore sizes, void spaces, or other properties. Either one, none or both of the membranes 120 , 160 may be treated to enhance their oleophobic properties. The membranes 120 , 160 are laminated to the fabric backing material 122 . The membrane assembly 82 c could be treated to increase oleophobicity after lamination. The membranes 120 , 160 could be located on opposite sides of the fabric backing material 122 .
[0065] The membrane assembly 82 c has a membrane side 164 and a fabric side 126 . The membrane assembly 82 c is hydrophobic on both the membrane side 164 and the fabric side 126 . That is, the membrane assembly 82 c prevents or resists the passage of liquids, such as water, through the laminated article. The membrane assembly 82 c is gas permeable and moisture vapor transmissive. That is, the membrane assembly 82 c permits the passage of gases, such as air, carbon dioxide and water vapor, through it.
[0066] The membrane assembly 82 c has enhanced oleophobic properties. The addition of the oleophobic treatment increases the resistance of the membrane assembly 82 c to leakage or being wet by resin, oil or oily substances. The membrane assembly 82 c has an oil hold out or resistance rating of at least a number 8 as determined by AATCC 118 testing and preferably at least a number 8+ rating so it can inhibit resin flow through the membrane assembly when the surface tension of the resin at 25 C is lower than 19.61 dynes/cm. The membrane assembly 82 c also has an air permeability of at least 0.01 CFM/ft 2 at 125 Pascal per square foot of membrane measured by ASTM D737 testing.
[0067] An alternate aspect of the invention is to use two or more membrane assemblies 82 c physically overlaid together instead of being laminated together. In testing, a sample membrane structure included three membrane assemblies 82 c overlaid together. The resultant membrane structure resisted leakage and wetting with the RTM-6 resin and hardener mix until the temperature of the resin and hardener mix reached 180° C. The surface tension at 180° C. for the RTM-6 resin and hardener mix is about 13 dynes/cm. In terms of AATCC 118 testing, the membrane assembly 82 has a hold out rating of at least a number 8 and even a number 8+. Air permeability of this membrane structure was 0.1 CFM at 125 Pascal per square foot of membrane measured by ASTM D737 testing.
[0068] While the invention has been described in terms of various specific embodiments, those skilled in the art will recognize that the invention extends beyond the specifically disclosed embodiments to other alternative embodiments and/or uses of the systems, techniques and obvious modifications and equivalents of those disclosed. It is intended that the scope of the invention disclosed should not be limited by the particular disclosed embodiments described above. | A method of manufacturing a fiber-reinforced article. The method includes the steps of providing a mat fiber stricture defining voids therein. A membrane structure is applied over at least a portion of the fiber structure. The membrane structure includes a microporous membrane. At least the microporous membrane of the membrane structure has an oil resistance rating of at least a number 8 determined by AATCC 118 testing. A resin and hardener mix is provided. The resin is infused into voids of the fiber structure by applying a vacuum to the fiber structure and the membrane structure wherein the membrane structure inhibits the flow of resin therethrough. | 8 |
[0001] This application claims priority to U.S. provisional patent application Ser. No. 60/620,839 filed Oct. 21, 2004 and U.S. provisional patent application Ser. No. 60/583,293 filed Jun. 25, 2004, both of which are incorporated herein by reference.
FIELD OF THE INVENTION
[0002] The present invention generally relates to increasing the efficiency of in vitro fertilization by decreasing the rate of polyspermy.
BACKGROUND
[0003] Although embryos produced by in vitro maturation (IVM)/in vitro fertilization (IVF) develop to the blastocyst stage, a high incidence (often exceeding 50%) of polyspermy remains a major impediment to the development of efficient systems of IVF in pig. Wang et al., J Reprod Fertil (1997) 111, 101-108. Polyspermic fertilization occurs less frequently in vivo than in vitro in the pig, with the incidence of polyspermy in vivo often less than 5%. Hunter, Mol Reprod Dev (1991), 29:385-391. Polypronuclei can participate in karyosyngamy and the resulting polyploid eggs can develop into diploid, triploid, or mosaic fetuses (Xia, Microscopy Research and Technique (2003), 61, 325-326) that would have difficulty in completing gestation. Polyspermic fertilization occurs more frequently in the pig than in the other species, even for in vivo fertilization under diverse experimental conditions. Hunter, J Reprod Fertil (1967) 13, 133-147; Hunter, J Reprod Fertil (1990) 40, 211-226; Hunter, Mol Reprod Dev (1991) 29, 385-391.
[0004] Various approaches have been employed in attempts to overcome the problem of polyspermic fertilization. See generally Funahashi, Reprod Fert Dev (2003) 15, 167-177. Some researchers have focused on the type of IVF medium and certain modifications to that medium in an attempt to mimic in vivo conditions in the oviducts. For example, researchers have co-cultured spermatozoa with oviduct cells (Nagai and Moor, Mol Reprod Dev (1990) 26, 377-382), follicle cells (Wang et al., J Reprod Dev (1992) 38, 125-131), oviductal fluid (Kim et al., J Reprod Fertil (1996) 107, 79-86), follicular fluid (Funahashi and Day, J Reprod Fertil (1993) 99, 97-103), and other substances (Funahashi et al., Biol Reprod (2000) 63, 1157-1163). While reducing sperm number during IVF decreased polyspermic penetration, it also reduced sperm penetration rates. Abeydeera and Day, Biol Reprod (1997) 57, 729-734. But in the approaches listed above, reduction of polyspermic penetration generally came at the cost of an overall reduction in the efficiency of fertilization. In addition, undefined biologicals (such as co-culture with oviduct cells, or addition of follicular fluid, or oviductal fluid) are unstable factors, and these results are not readily repeatable. Li et al., Biol Reprod (2003) 69, 1580-1585. Other suggested approaches include use of embryo cryopreservation straws rather than microdrops (Li et al., Biol Reprod (2003) 69, 1580-1585) and controlling sperm-zona binding (Funahashi, Reprod Fert Dev (2003) 15, 167-177).
[0005] Several researchers have focused upon the problem of polyspermy specifically in pig. Pig oocytes flushed from the oviduct on Day 2 of the estrous cycle and subsequently fertilized in vitro have been observed to have a much lower incidence of polyspermy (28%) than oocytes matured and fertilized in vitro (62%). Wang et al., Mol Reprod Dev (1998) 49:308-316. Other pig-specific attempted solutions to the problem of IVF polyspermy include use of periovulatory oviduct-conditioned media (Vatzias and Hagen, Biol Reprod (1999) 60, 42-48), oviduct fluid (Funahashi and Day, J Reprod Fertil (1993) 99, 97-1038; Kim et al., Zygote (1997) 5, 61-65), and coincubation of boar spermatozoa or pig oocytes with oviductal epithelial cells (Nagai and Moor, Mol Reprod Dev (1990) 26, 377-382; Kano et al., Theriogenology (1994) 42, 1061-1068; Dubuc and Sirard, Mol Reprod Dev (1995) 41, 360-367).
[0006] Osteopontin is an extracellular matrix protein; it is an acidic single chain phosphorylated glycoprotein component. In general, osteopontin is a monomer ranging in length from 264-301 amino acids that undergoes extensive post-translational modification, including phosphorylation, glycosylation, and cleavage resulting in molecular weight variants ranging from 25-75 kDa. Johnson et al., Biol Reprod (2003) 69, 1458-1471. Among several reported functions, osteopontin has been reported to be involved with mammalian reproductive systems. Johnson et al., Biol Reprod (2003) 69, 1458-1471; Garlow et al., Biol Reprod (2002) 66, 718-725. One researcher has reported that treating bovine oocytes with purified bovine milk osteopontin increased the rate of cleavage and embryonic development in vitro. Goncalves et al., Soc for Study of Reprod (2003) 68 supp. 1, 336-337.
SUMMARY OF THE INVENTION
[0007] Among the various aspects of the present invention may be noted a process for in vitro fertilization with a lower incidence of polyspermic fertilization. The process and associated compositions are particularly advantageous in connection with the in vitro fertilization of swine. Briefly, therefore, the present invention is directed to compositions and a process for reducing polyspermy in the production of embryos. The process comprises forming a mixture containing an anti-polyspermy agent, oocytes, and sperm and allowing the sperm to fertilize the oocyte. The composition contains osteopontin, oocytes, and sperm.
[0008] Other objects and features will be in part apparent and in part pointed out hereinafter.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] FIG. 1 is an image of the acrosome reaction on the surface of the zona pellucida as observed with an epi-fluorescent microscope at 1000× magnification. Letters “a” and “e” designate spermatozoa with a reacted acrosome. Letter “b” designates a spermatozoa with an intact acrosome. Letters “c” and “d” designate spermatozoa without an acrosome. FIG. 1A shows the DNA staining. FIG. 1B shows the acrosomal staining. FIG. 1C shows the merged images. Numeral “1” designates the acrosomal region of spermatozoon. Numeral “2” designates the nuclear region of spermatozoon. Methodology is as described in Example 5.
DETAILED DESCRIPTION OF THE INVENTION
[0010] Surprisingly, it has been discovered that the incidence of polyspermy during the production of embryos can be reduced during in vitro fertilization by the use of osteopontin and equivalent anti-polyspermy agents during in vitro fertilization procedures. While such anti-polyspermy agents can generally be used during in vitro fertilization of a range of species, e.g., porcine, human, bovine, canine, equine, ovine, avian, and rodent, they offer particular advantages during porcine in vitro fertilizations in which there tends to be a greater incidence of polyspermy.
[0011] The process of the present invention comprises forming an in vitro fertilization mixture containing the anti-polyspermy agent, an oocyte, and sperm, and allowing the sperm to fertilize the oocyte. In vitro fertilization processes are well known; see e.g. Fan and Sun, Methods in Molecular Biology, vol. 253, Germ Cell Protocols, vol. 1 Sperm and Oocyte Analysis, Ed. Shatten, Humana Press Inc., Totowa, N.J. (2004) 227-233. Except as otherwise noted herein, therefore, the process of the present invention is carried out in accordance with any such processes.
[0012] In general, the anti-polyspermy agent is osteopontin or an analog or mimic thereof. Osteopontin contains the conserved Arg-Gly-Asp (RGD) sequence, which is known to interact with cell surface receptors. Osteopontin also contains over twenty conserved phosphoacceptor serine residues, generally localized in Ser/Thr-X-Glu/Ser(P)/Asp or Ser-X-X-Glu/Ser(P) motifs. Preferably, the osteopontin is a purified osteopontin. Wild-type osteopontin can be obtained as described in, for example, McFarland et al., Annals New York Acad Sciences (1995) 760, 327-331. Mutant osteopontin can be obtained as described in, for example, Johnson et al., Biol Reprod. (2001) 65, 820-828.
[0013] The concentration of the anti-polyspermy agent will typically be in the range of about 0.001 to about 1.0 micrograms per milliliter of fertilization mixture. For example, when the anti-polyspermy agent is osteopontin, the concentration is preferably in the range of about 0.01 to about 0.1 μg/ml. In addition, while the anti-polyspermy agent can be immobilized to beads or other solid support (e.g., the interior surface of the container holding the in vitro fertilization mixture), it is generally preferred that the agent be dissolved in the in vitro fertilization mixture.
[0014] In the absence of an anti-polyspermy agent, the polyspermy rate (number of oocytes with >1 sperm/total number of oocytes penetrated) in pig is typically greater than about 40%, often exceeding about 50%. In one embodiment of the present invention, the addition of osteopontin reduces the rate of polyspermy to less than about 36%. For example, osteopontin can reduce the rate of polyspermy to less than about 33%, less than about 30%, less than about 27%, less than about 25%, less than about 23%, less than about 20%, less than about 18%, less than about 16%, or less than about 14% (see e.g. Example 4; Table 1).
[0015] Oocyte Mixture
[0016] In one embodiment, the in vitro fertilization mixture is formed by combining sperm with a pre-formed oocyte mixture containing at least one oocyte, the anti-polyspermy agent, and optionally one or more additives. Typically, an oocyte mixture is formed by combining a buffer appropriate for IVM or IVF with one or more oocytes, the anti-polyspermy agent, and one or more additives, for example, a metabolite such as pyruvate, a sugar such as glucose or sorbitol, caffeine, an enzyme such as hyaluronidase, an antibiotic such as gentamicin, penicillin, or streptomycin, or an amino acid or amino acid analog such as cysteine, glutamine, taurine, or hypotaurine. Other suitable additives are described in further detail in, for example, Fan and Sun (2004). In a preferred embodiment, the buffer is a modified TCM 199 buffer (see e.g. Example 1). In another embodiment, the pre-formed oocyte mixture contains at least one oocyte, a buffer, and one or more additives, wherein the osteopontin is added to the in vitro fertilization mixture either simultaneously with the oocyte mixture and the sperm mixture, or as a component of the sperm mixture.
[0017] Oocyte(s) to be included in the oocyte mixture can be obtained commercially (e.g., BoMed, Madison, Wis.) or collected directly from a female. As an example, oocytes can be collected as cumulus-oocyte complexes and matured in a suitable in vitro oocyte maturation medium (see e.g. Examples 1, 2). Procedures for IVM of oocytes from porcine follicles to acquire meiotic competence and capacity to be fertilized are described in, for example, Abeydeera et al., Biol. Reprod. (1998) 58, 1316-1320; and Abeydeera et al., Zygote (2001) 9, 331-337. As an example, approximately 25-100 cumulus-oocyte complexes can be matured in approximately 500 μl of in vitro maturation medium covered with mineral oil (see e.g. Example 2). Oocyte maturation can occur from about 37° C. to about 40° C. Preferably, oocyte maturation will occur at about the body temperature of the subject animal. For example, in porcine, oocyte IVM can be carried out at about 39° C. Maturated oocytes can then be stripped of the cumulus cells and suspended in a suitable IVF medium, such as a modified Tris-buffered medium, as described in Example 1 or Fan and Sun (2004). Whether or not osteopontin is present, after oocytes are matured, they can be transferred into droplets of a medium suitable for IVF. The fertilization droplets containing oocytes can be, for example, approximately 50 μl, covered in mineral oil, and equilibrated 40-44 hours at 38.5° C. in 5% CO 2 in air (see e.g. Examples 2, 3).
[0018] Osteopontin or another anti-polyspermy agent can be introduced to the oocyte mixture at any point during the above described procedures. For example, osteopontin can be added at a concentration of about 0.001 to about 1.0 μg/ml of the final oocyte mixture. In one preferred embodiment, osteopontin is added at a concentration of about 0.01 to about 0.1 μg/ml to the oocyte IVM mixture so as to be present during the maturation process.
[0019] The oocyte mixture can optionally be incubated for a period of time before it is combined with sperm to form the IVF mixture. For example, the oocyte mixture can be incubated for a period of up to about 48 hours before being combined with sperm to form the IVF mixture. Preferably the oocyte mixture is incubated for over two hours up to about 48 hours.
[0020] Sperm Mixture
[0021] Sperm useful to the methods of the invention can be obtained commercially (e.g., Lone Willow USA, Inc., Roanoke, Ill.) or collected directly from a male. Collected sperm can be used directly as a fresh ejaculate or extended, sorted, and/or cryopreserved and used later in accordance with conventional procedures. See e.g. Fan and Sun (2004); Pursel and Johnson, J Anim Sci (1976) 42, 927-931. Cryopreservation can be practiced as described in, for example, Suzuki et al., Microscopy Research & Technique (2003) 61, 327-334. Presorting of sperm to select for X chromosome or Y chromosome bearing sperm can be practiced as described in, for example, Abeydeera et al., Theriogenology (1998) 50, 981-988. The sperm used for fertilization can be used to carry into the oocyte DNA for sperm-mediated transgenesis, as described in, for example, Lavitrano et al., Molecular Reproduction and Development (2003) 64, 284-297.
[0022] Regardless of source, the sperm mixture generally contains sperm suspended in a medium. The medium may include seminal fluid, buffer, and/or additives. For example, the medium of the sperm mixture may be exclusively seminal fluid (i.e., neat ejaculate), a mixture of seminal fluid and a buffer, or exclusively buffer. Among other things, the buffer should be non-toxic to the cells and can enhance sperm viability by buffering the sperm suspension against significant changes in pH or osmotic pressure. Exemplary buffers include phosphates, diphosphates, citrates, acetates, lactates, and combinations thereof. Additionally, the sperm mixture may or may not contain an anti-polyspermy agent, for example osteopontin. In one embodiment, the sperm mixture is fresh ejaculate. In another embodiment, the sperm mixture contains sperm, seminal fluid, and osteopontin. In a further embodiment, the sperm mixture contains sperm, a buffer (preferably a buffer suitable for sperm washing, sperm maturation, or IVF), and osteopontin.
[0023] Osteopontin or other anti-polyspermy agent can be introduced to the sperm mixture at any point in the previously described steps. For example, osteopontin can be included during washing or resuspension of the cryospreserved sperm mixture. Or, osteopontin can be included in the diluted sperm mixture prior to cryospreservation of the sperm sample. Regardless of the point of introduction, the osteopontin or other anti-polyspermy agent will typically be added at a concentration of about 0.001 to about 1.0 micrograms per milliliter of the final sperm mixture. For example, osteopontin can be added at a concentration of about 0.01 to about 0.1 μg/ml.
[0024] Optionally, the sperm mixture can be incubated for a period of time before being combined with an oocyte to form an IVF mixture. For example, the sperm mixture can be incubated up to about 6 hours.
[0025] In Vitro Fertilization Mixture
[0026] The IVF mixture of the present invention contains sperm, at least one oocyte, and the anti-polyspermy agent. These components can be combined through various routes. For example, a pre-formed oocyte mixture containing the anti-polyspermy agent can be combined with sperm. Alternatively, a pre-formed sperm mixture containing the anti-polyspermy agent can be combined with at least one oocyte. In another alternative approach, a pre-formed oocyte mixture containing the anti-polyspermy agent is combined with a pre-formed sperm mixture containing the anti-polyspermy agent. In yet another alternative approach, the anti-polyspermy agent is introduced into the IVF mixture simultaneously with or subsequent to the introduction of the sperm and oocyte(s) into the mixture. Preferably, a sperm mixture is combined with a droplet of oocyte mixture to form an IVF droplet. As an example, approximately 50 μl of sperm sample can be added to an oocyte droplet, providing a final sperm concentration of about 1×10 5 cells/ml to about 1×10 6 cells/ml (see e.g. Example 3).
[0027] In Vitro Fertilization
[0028] The IVF mixture can be incubated for a period of time after sperm and oocytes are combined to allow fertilization to occur. In one embodiment, the IVF mixture is incubated up to about 6 hours. For example, the IVF mixture can be incubated for up to about 5 hours. As another example, the IVF mixture can be incubated for up to about 1 hour. Typically, fertilization will occur within about one hour. As an example, an IVF droplet containing oocytes, sperm, and osteopontin can be incubated at 38.5° C. in an atmosphere of 5% CO 2 in air and 100% relative humidity (see e.g. Example 3).
[0029] The spermatozoa can be removed at the beginning of the fertilized oocyte incubation period or at any time throughout the developmental incubation period. One skilled in the art will recognize that the time of optimal sperm removal is closely correlated to the desired rate of oocyte penetration. Generally, 50% is acceptable penetration, while at least about 80% or at least about 90% is preferred. As an example, the embryos can be harvested at 24 hours to check for the presence of pronuclei and vortexed to remove sperm bound to the zona pellucida. As another example, porcine embryos can be harvested at 18 hours to check for the presence of pronuclei and vortexed to remove sperm bound to the zona pellucida. Removal of loosely attached sperm can be performed, for example, by washing three times in a suitable developmental medium such as NCSU 23 with 0.4% BSA or PZM3 (see e.g. Example 3).
[0030] In several embodiments, the addition of osteopontin increases the efficiency of IVF (number of oocytes with 1 male and 1 female pronucleus/total number of oocytes inseminated) without substantially decreasing penetration rate (number of oocytes penetrated by sperm/total number of oocytes inseminated). In vitro fertilization rates are determined by measuring the percent fertilization of oocytes in vitro. At the end of the incubation of sperm and oocytes, oocytes can be stained with an aceto-orcein stain or the equivalent to determine the percent oocytes fertilized. Alternatively, fertilized oocytes can be left in culture for about 2 days, during which division occurs and the number of cleaving embryos (i.e., 2 or more cells) are counted. Nuclear status (pronuclear, sperm head, sperm tail, MII chromosome, Pb1, Pb2) can be assessed by examining the stained oocytes under a phase contrast microscope. See e.g. Abeydeera et al., Biol Reprod (1998) 58:1316-1320. In one embodiment, addition of osteopontin increases the efficiency of IVF to greater than about 35%. For example, addition of osteopontin can increase the efficiency of IVF to greater than about 38%, greater than about 40%, greater than about 42%, greater than about 44%, greater than about 46%, greater than about 48%, or greater than about 50%.
[0031] Additives
[0032] Various additives can be included in the in vitro fertilization mixture to further reduce the incidence of polyspermy or increase the efficiency of fertilization. For example, porcine oviduct-specific glycoprotein can be included in porcine IVF mixtures; porcine oviduct-specific glycoprotein is known to reduce the incidence of polyspermy in pig oocytes, reduce the number of bound sperm, and increase post-cleavage development to blastocyst. Kouba et al., Biol Reprod (2000) 63, 242-250. According to the methods of the invention, the addition of osteopontin in conjunction with porcine oviduct-specific glycoprotein will further decrease the incidence of polyspermy in porcine IVF.
[0033] Such additives can be introduced to the IVF mixture by various routes. For example, the additive can be included in an oocyte mixture which is then combined with sperm to form the IVF mixture, it can be included in a sperm mixture which is combined with an oocyte or oocyte mixture to form the IVF mixture, or it can be added directly to the IVF mixture after sperm and oocyte are combined.
[0034] Use of Embryo
[0035] In one embodiment, the fertilized oocyte is cultured to produce an embryo. An “embryo” refers to an animal in early stages of growth following fertilization up to the blastocyst stage. The blastocyst stage has two cell types: the inner cell mass cells, which are generally considered totipotent cells; and the trophectoderm cells which are generally considered to be a differentiated epithelial cell layer (or sphere). In contrast, somatic cells of an individual are cells of a body that are differentiated and are not totipotent. After allowing sufficient time for fertilization and subsequent washing, the oocytes are transferred into a suitable development medium and incubated under conditions suitable for further development of fertilized oocytes into embryos. In general, the medium for culturing sperm, oocytes, or embryos will be a balanced salt solution, examples of which include Ml 99, Porcine Zygote Medium-3 (PZM3), Synthetic Oviduct Fluid, PBS, BO, Test-yolk, Tyrode's, HBSS, Ham's F10, HTF, Menezo's B2, Menezo's B3, Ham's F12, DMEM, TALP, Earle's Buffered Salts, CZB, KSOM, BWW Medium, and emCare Media (PETS, Canton, Tex.).
[0036] As an example, washing, transfer, incubation, and culturing of fertilized oocytes and embryos can be practiced as described in Fan and Sun (2004); and Petters and Wells, J Reprod Fertil (1993) 48, 61-73. As a further example, the oocytes can be washed in a development medium, such as Porcine Zygote Medium with BSA, transferred into 500 μl of the same development medium in a 4-well Nunclon dish, covered with mineral oil (to prevent drying of sample and alteration of osmolarity) and incubated at 38.5° C. in an atmosphere of 5% CO 2 in air and 100% relative humidity (see e.g. Example 3). The presence of CO 2 would only be necessary to the extent that bicarbonate buffers are utilized, thus requiring ambient CO 2 for pH maintenance.
[0037] In one embodiment, osteopontin is combined with an embryo culture mixture. Such addition can improve the function of an embryo (i.e., improve the potential for normal development of the embryo). This potential of embryos is assessed by evaluating chromosome numbers, cell numbers, cytoskeleton formation and metabolic activity. Improved function means that the embryo has enhanced performance as assessed by one of these assays when treated with osteopontin under conditions described herein as compared to a control (i.e., no treatment with osteopontin). Preferably, the test of normal fertilization and function is embryo transfer and development to term.
[0038] In another embodiment, fertilized embryos or cultured fertilized embryos produced by the methods of the invention can be transferred to the reproductive tract of a surrogate animal. For example, fertilized embryos can be transferred to the reproductive tract of a gilt or sow. See e.g. Lai and Prather, Cloning & Stem Cells (2003) 5, 233-242.
[0039] Alternatively, the embryos might be cultured in vitro (see e.g. Im et al., Theriogenology. (2004) 61, 1125-1135), or in vivo (see e.g. Prather et al. Theriogenology (1991) 35, 1147-1151) prior to surgical (Cabot et al., Anim. Biotech. (2001) 12:(2) 205-214) or non-surgical embryo transfer to a suitable surrogate animal, for example a gilt or sow (see e.g. Martinez et al., Theriogenology (2003) 61, 137-146). Such embryos might be frozen or vitrified and thawed prior to the transfer (see e.g. Misumi et al., Theriogenology (2003) 60, 253-260).
[0040] After fertilization and before embryo transfer, the embryos can be cloned by nuclear transfer (see e.g. Prather et al., Biol. Reprod. (1989) 41:414-418) or made transgenic by a variety of methods including, but not limited to, pronuclear injection or viral transduction (see e.g. Wolf et al., Experimental Physiology (2000) 85, 615-625).
[0041] Having described the invention in detail, it will be apparent that modifications and variations are possible without departing the scope of the invention defined in the appended claims. Furthermore, it should be appreciated that all examples in the present disclosure are provided as non-limiting examples.
EXAMPLES
[0042] The following non-limiting examples are provided to further illustrate the present invention. It should be appreciated by those of skill in the art that the techniques disclosed in the examples that follow represent approaches the inventors have found function well in the practice of the invention, and thus can be considered to constitute examples of modes for its practice. However, those of skill in the art should, in light of the present disclosure, appreciate that many changes can be made in the specific embodiments that are disclosed and still obtain a like or similar result without departing from the spirit and scope of the invention.
EXAMPLE 1
Media
[0043] Unless otherwise stated, all chemicals used in this study were purchased from Sigma Chemical Co. (St. Louis, Mo.). Oocyte maturation medium was prepared as TCM 199 (Gibco BRL, 31100-76) supplemented with 0.1% PVA (w/v), 3.05 mM D-glucose, 0.91 mM sodium pyruvate, 75 μg/ml penicillin G, and 50 μg/ml streptomycin. The following were added fresh each time before use: 0.57 mM cysteine, 0.5 μg/ml luteinizing hormone (LH; Sigma, L-5269), 0.5 μg/ml follicle stimulating hormone (FSH; Sigma, F-2293), and 10 ng/ml epidermal growth factor (EGF; Sigma, E-4127). IVF medium was a modified Tris-buffered medium (mTBM) containing 2 mg/ml BSA and 2 mM caffeine. Osteopontin was diluted with PBS to a concentration of 0.001, 0.01, 0.1, or 1.0 μg/ml in mTBM. Sperm washing medium was Dulbecco phosphate-buffered saline (dPBS; Gibco) supplemented with 1 mg/ml BSA (pH 7.3). The culture medium for embryonic development was Porcine Zygote Medium-3 (PZM3, pH 7.3) medium supplemented with 3 mg/ml BSA.
EXAMPLE 2
Collection of Porcine Oocytes and In Vitro Maturation
[0044] Ovaries were collected from prepubertal gilts at a local abattoir and stored in 0.9% NaCl solution at 30-35° C. Cumulus-oocyte complexes (COCs) were aspirated from antral follicles (3-6 mm in diameter) with an 18-gauge needle fixed to a 10-ml disposable syringe. COCs with uniform cytoplasm and several layers of cumulus cells were selected and rinsed three times in TL-Hepes containing 0.1% (w/v) polyvinyl alcohol (PVA). Approximately 50-70 COCs were transferred into 500 μl IVM medium. The medium had been covered with mineral oil in a four-well Nunclon dish (Nunc, Roskilde, Denmark). The oocytes were matured for 4044 hr at 38.5° C., 5% CO 2 in air.
EXAMPLE 3
Production of Porcine Preimplantation Embryos by In Vitro Fertilization
[0045] Cumulus-free oocytes were washed three times in IVF medium. Approximately, 30-35 oocytes were transferred into 50 μl droplets of IVF medium covered with mineral oil that had been equilibrated for 40 hr at 38.5° C. in 5% CO 2 in air. The dishes were kept in a CO 2 incubator until sperm were added for insemination. For IVF, one 0.1 ml frozen semen pellet was thawed at 39° C. in 10 ml sperm washing medium. After washing 2 times by centrifugation (1900×g, 4 min), cryopreserved ejaculated spermatozoa were resuspended with fertilization medium to a concentration of 2×10 6 cells/ml. Fifty μl of the sperm sample was added to the fertilization droplets containing the oocytes, giving a final sperm concentration of 1×10 6 cells/ml. Osteopontin was added to the fertilization droplet at concentrations of 0.0, 0.001, 0.01, 0.1, or 1.0 μg/ml. Oocytes were co-incubated with the sperm for 6 h at 38.5° C. in an atmosphere of 5% CO 2 in air and 100% humidity. At six-hour postinsemination, oocytes were washed 3 times and cultured in 500 ul culture medium in 4-well Nunclon dishes at 38.5° C., in 5% CO 2 in air.
EXAMPLE 4
Evaluation of In Vitro Fertilization
[0046] At the end of the co-incubation period described above, oocytes were washed three times in development medium and transferred into 4-well Nunclon multidishes containing 500 μl of the same medium covered with 500 μl mineral oil and returned to the incubator for further development. After 18 h from the onset of IVF, half of the oocytes were transferred into one well of a 4-well plate, and the spermatozoa removed from the other half by vortexing for 1 min. After washing 3 times, the fertilized oocytes were transferred to the center of a glass microscope slide, covered with a cover slip and fixed with fresh fixing medium (25% (v/v) acetic acid in ethanol) for 72 h at room temperature. Orcein (1%, w/v) in 45% (v/v) acetic acid was added and the oocytes stained for 10 min at room temperature. The oocytes were then washed with 20% glycerol and 20% acetic acid in water. The slide was cleaned and then sealed with nail polish. Nuclear status (pronuclear, sperm head, sperm tail, MII chromosome, Pb1, Pb2) was then determined under a phase-contrast microscope at 400×.
[0047] The following effects of osteopontin on fertilization parameters were evaluated: penetration rate (number of oocytes penetrated by sperm/total number of oocytes inseminated), polyspermy rate (number of oocytes with >1 sperm/total number of oocytes penetrated), male pronuclear formation rate (number of oocytes with >1 male pronucleus/total number of oocytes penetrated), normal fertilization efficiency (number of oocytes with 1 male and 1 female pronucleus/total number of oocytes inseminated), and mean number of sperm penetrated per oocyte.
[0048] Experiments were repeated with 10 to 14 replications. Data (mean±SEM) were subjected to GLM of SAS followed by a protected LSD test. A p-value of less than 0.05 (p<0.05) was considered statistically significant.
[0049] Exemplary results demonstrated that osteopontin can decrease the incidence of polyspermy in pig IVF and result in an overall more efficient procedure (as a non-limiting example, approximately 44%) based on the number of oocytes inseminated. See e.g. Table 3. In these studies, the polyspermy rate decreased as the osteopontin concentrations increased: 0.01-1 μg/ml significantly reduced the polyspermy rate, compared to the control. See e.g. Table 1. Also, all levels of osteopontin significantly reduced the mean number of sperm in each oocyte as compared to the controls, and the effect was concentration dependent. At 0.01, 0.1 and 1.0 μg/ml osteopontin, the monospermy rate was increased as compared to the controls. See e.g. Table 2. The male pronucleus rate was decreased by the highest level of osteopontin as compared to the control. See e.g. Table 3. The overall fertilization rate (1 male and 1 female pronucleus per total number of oocytes inseminated) was elevated at 0.001 μg/ml osteopontin and significantly higher at 0.01 and 0.1 μg/ml osteopontin as compared to the control. See e.g. Table 3.
TABLE 1 Effect of OPN on polyspermy of pig oocytes during IVF. OPN No. No. Penetrated No. of sperm per (μg/ml) oocytes oocytes Polyspermy (%) Oocyte (%) 0.0 147 104 38.8 ± 3.1 a 1.49 ± 0.06 a 0.001 137 99 32.9 ± 3.1 a,b 1.29 ± 0.06 b 0.01 150 105 27.2 ± 3.1 b,c 1.22 ± 0.06 b,c 0.1 149 92 20.8 ± 3.1 c,d 1.21 ± 0.06 b,c 1 133 62 16.4 ± 3.1 d 1.08 ± 0.06 c Within a column, values with different superscripts are significantly different (p < 0.05). Values are expressed as means ± SEM of ten replicates. Percentage polyspermy is calculated from the number of oocytes inseminated. Mean numbers of sperm are calculated from the number of penetrated oocytes.
[0050]
TABLE 2
Effect of OPN on sperm penetration of pig oocytes during IVF.
OPN
No.
No. Penetrated
Penetration
(μg/ml)
Oocytes
oocytes
Rate (%)
Monospermy (%)
0.0
147
104
70.8 ± 2.9 a
45.7 ± 4.9 a
0.001
137
99
74.6 ± 2.9 a
57.5 ± 4.9 a,b
0.01
150
105
73.7 ± 2.9 a
63.3 ± 4.9 b
0.1
149
92
67.7 ± 2.9 a
69.0 ± 4.9 b
1
133
62
49.3 ± 2.9 b
70.2 ± 5.2 b
Within a column, values with different superscripts are significantly different (p < 0.05). Values are expressed as means ± SEM of fourteen replicates. Percentage penetration is calculated from the number of oocytes inseminated. Percentage monospermy is calculated from the number of total penetrated oocytes.
[0051]
TABLE 3
Effect of OPN on pronuclear formation of pig oocytes during IVF.
OPN
No.
No. Penetrated
Male
Fertilization
(μg/ml)
oocytes
oocytes
Pronucleus (%)
Efficiency (%)
0.0
147
104
59.5 ± 3.4 a
31.6 ± 3.4 c
0.001
137
99
65.7 ± 3.4 a
41.6 ± 3.4 a,b,c
0.01
150
105
63.2 ± 3.4 a
42.6 ± 3.4 a,b
0.1
149
92
57.1 ± 3.4 a
44.6 ± 3.9 a
1
133
62
40.6 ± 3.4 b
32.9 ± 3.4 b,c
Within a column, values with different superscripts are significantly different (p < 0.05). Values are expressed as means ± SEM of fourteen replicates. Percentage male pronucleus is calculated from the number of penetrated oocytes. Percentage normal fertilization are calculated from the number of oocytes inseminated.
EXAMPLE 5
Effect of Osteopontin on Sperm Function
[0052] To examine if the decreased polyspermy in vitro resulted from the changes in sperm function the effects of OPN on sperm motility, progressive motility, viability, and acrosome reaction were investigated.
[0053] Thawed sperm were incubated in mTBM containing 0, 0.1, or 1 μg/ml OPN for 2, 4, or 6 h at 38.5° C., in 5% CO 2 in air. The time immediately after thawing served as the 0 h group for all experiments. Porcine sperm motility and progressive motility for samples were analyzed at 0, 2, 4, and 6 h on a computer aided semen analyzer (Hamilton Thorne IVOS v 12.2c, Beverly, Mass.). Motility was defined as the percentage of spermatozoa that exhibited any movement of the sperm head. Progressive motility was defined as the percentage of spermatozoa that exhibited linear velocity of 45 μm/sec with a straightness of 45%.
[0054] Sperm viability was assessed in a fluorometric assay after being stained with propidium-iodide (PI, Sigma). Thawed semen samples were well mixed, transferred to 50 μl of IVF medium (pre-equilibrated with OPN overnight) containing various concentrations of OPN (0, 0.1 or 1 μg/ml) and co-incubated with spermatozoa for 0, 2, 4, or 6 h. At different points, PI (10 μg/ml) was added for 30 min in an incubator with CO 2 in the dark. After incubation, the sperm were transferred (10 μl) onto a glass slide, smeared, and mounted with an antifade reagent (ProLong®, Molecular Probes), covered with a glass cover slip, and sealed. Fluorescence was determined by using an epi-fluorescent microscope (Nikon, Tokyo, Japan). Sperm were observed at ×400 magnification, and at least 200 cells were evaluated per sample. Spermatozoa stained with PI were considered to have damaged membranes. The percentage of spermatozoa without PI staining is the sperm viability. Each group was replicated six times.
[0055] Results showed that the percentages of sperm motility, progressive motility, and viability decreased in all groups at 2 h after IVF, but were not different (p>0.05) between treatment groups.
[0056] Sperm acrosome reaction was investigated by staining with Alexa-PNA/DAPI, according to the procedure described by Sutovsky (Methods in Molec. Bio. (2003) 253, 59-77, Humana Press, Totowa, N.J.) and Katayama et al. (Human Reprod. (2002) 17, 2657-2664), with slight modifications. At 4 or 6 h after IVF, the oocytes were washed three times in 400 μl of dPBS-PVP medium in a prewarmed glass plate with 4-well dish on a slide warmer set to 37° C., and pipetted in and out (10 times) to remove loosely bound sperm. The oocytes were transferred into 400 μl of 2% formaldehyde in dPBS for 40 min at room 180 temperature (RT) for fixing. After fixation, the oocytes were washed twice in dPBS-PVP at RT, and then transferred to 0.1% triton X-100 in dPBS for 40 min at RT to permeabilize the oocytes. The oocytes were incubated in 0.4 μg/ml (1:500) Alexa-Fluo 488-PNA (Cat#L-21409, Molecular Probes) in 0.1% triton X-100 in dPBS for 40 min in the dark, and then transferred into 0.1% triton X-100 in dPBS for 5 min. The oocytes were transferred to a standard microscopy slide, in 8 μl mounting medium with DAPI (VECTASHIEID, H-1200, VECTOR) and covered with a cover slip that was then sealed with nail polish. Fluorescence was determined by using an epi-fluorescent microscope (Nikon, Tokyo, Japan). Sperm were observed at 1000× magnification, and 10 oocytes were evaluated per sample. The sperm around the ZP were counted according to Alexa-PNA and DAPI staining: spermatozoa were considered to be acrosome intact as determined by an Alexa-PNA-stained acrosome at top of the sperm with a DAPI nucleus. Sperm that had an acrosome area not stained with Alexa-PNA were considered to be acrosome reacted. The percentages of the number of the acrosome-reacted and the acrosome-intact in total spermatozoa around the ZP were examined. Each group was replicated 3 times.
[0057] Results from observing the acrosome reaction with a fluorescence microscope at 4 h after IVF showed that the sperm bound to the ZP of the 1 μg/ml OPN treated oocytes had a higher rate of acrosome reaction as compared to 0 OPN (see e.g. FIG. 1 ). The lowest level of acrosome reaction was observed at 6 h after IVF with 0.1 μg/ml OPN (see e.g. Table 4).
TABLE 4 Acrosome reaction of sperm bound to the zona pellucida at 4 or 6 h after IVF. Total No. of OPN Total No. of Mean Sperm Oocytes Mean Sperm (μg/ml) Oocytes (4 hr) Bound 4 hr (%) (6 hr) Bound 6 hr (%) 0.0 30 75 ± 2.1 a 28 97 ± 1.7 a 0.1 30 76 ± 2.1 a 26 87 ± 1.8 b 1.0 20 87 ± 2.6 b 27 95 ± 1.8 a Within a column, values with different superscripts are different (p < 0.05). Values are expressed as means ± SEM of six replicates.
EXAMPLE 6
Effect of Osteopontin on Oocyte Function
[0058] Zona pellucida solubility or ‘hardness’ was measured after exposure to 0.1% pronase. Cumulus-free oocytes matured in vitro were transferred to 50 μl of mTBM (pre-200 equilibrated with OPN overnight) containing various concentrations of OPN (0, 0.1 or 1 μg/ml) and were incubated for 6 h with/without spermatozoa at 39° C., 5% (v/v) CO 2 in air. Groups of 10 were used for the experiment without OPN (control) or with OPN (0.1, 1 μg/ml OPN). The oocytes were transferred into PBS and washed three times, and then transferred into 100 μl of 0.1% (w/v) pronase solution in dPBS. Zonae pellucidae were continuously observed for dissolution under an inverted microscope equipped with a warm plate at 37° C. The dissolution time of the ZP of each oocyte was registered as the time interval between placement of the samples in pronase solution and that when the ZP was no longer visible at a magnification of ×200. Each treatment was replicated six times. Results showed that the number of sperm bound per oocyte reduced as the concentration of OPN increased, but this was only significant (p<0.05) at 6 h after IVF (see e.g. Table 5).
TABLE 5 Effect of OPN on the number of sperm bound to the zona pellucida during IVF. OPN No. Sperm Bound No. Sperm Bound (μg/ml) 4 Hr. 6 Hr. 0.0 26.3 ± 12.1 99.3 ± 7.9 a 0.1 10.2 ± 12.1 64.9 ± 7.9 b 1.0 3.4 ± 12.1 47.1 ± 7.9 b Within a column, values with different superscripts are different (p < 0.05). Values are expressed as means ± SEM of six replicates.
[0059] Sperm binding to the ZP was examined according to the methods described by Kouba et al. (Reproduction (2000) 63, 242-250), with slight modification. Cumulus-free oocytes matured in vitro were transferred to 50 μl of mTBM (pre-equilibrated with OPN overnight) containing OPN (0, 0.1 or 1 μg/ml) and co-incubated with spermatozoa for 4 or 6 hr. After fertilization, the oocytes were washed three times in 500 μl of mTBM and pipetted in and out (10 times) of a 215 pipette to remove loosely bound sperm. The oocytes were then placed into 50 μl drops of mTBM containing Hoescht 33342 (bis-Benzamide; 1.3 mg/ml) and incubated for 30 min at 39° C., 5% CO 2 in air in the dark. Oocytes were then washed twice in 300 μl of TLHepes-PVA, mounted, and the number of tightly bound sperm/zygote counted by using an epi-fluorescent microscope 400× (Nikon, Tokyo, Japan). Each treatment was replicated six times, with 10 oocytes counted from each replicate. Results showed that the duration in seconds required for ZP enzymatic digestion in the 0.1 μg/ml OPN treated groups was longer than the control group (p<0.05) after incubation with spermatozoa for 6 hours (see e.g. Table 6).
TABLE 6 The duration (seconds) for ZP solubility of oocytes exposed to OPN and with or without spermatozoa at 6 hr after IVF. Duration of ZP Duration of ZP solubility with solubility with OPN OPN OPN and sperm and without sperm (μg/ml) (sec) (sec) 0.0 118 ± 8.9 a 159.1 ± 8.9 a 0.1 204.3 ± 8.9 b 217.7 ± 8.9 b 1.0 149.1 ± 8.9 a 152.8 ± 8.8 a Within a column, values with different superscripts are different (p < 0.05). Values are expressed as means ± SEM of six replicates. | The field of invention generally relates to increasing the efficiency of in vitro fertilization by decreasing the rate of polyspermy. One aspect of the invention provides a method of reducing polyspermy in in vitro fertilization by forming an in vitro fertilization mixture that contains osteopontin, oocytes, and sperm, and allowing fertilization of the oocyte by sperm. Another aspect of the invention provides an aqueous mixture for in vitro fertilization that contains osteopontin, oocytes, and sperm. | 2 |
BACKGROUND OF THE INVENTION
The invention relates to iridium and the Zr- and Hf-free alloys thereof, as well as to rhodium and the Zr- and Hf-free alloys thereof, having high creep rupture strength at high temperatures.
Iridium, one of the metals of the platinum group, is used for example in crucibles for growing single crystals of high-melting oxidic melts, e.g. of Nd:YAG laser crystals, or in components for the glass industry. For these applications, not only the corrosion resistance with respect to oxidic melts, but also high creep resistance and creep rupture strength of the iridium at high temperatures are of crucial importance.
A method for increasing the creep resistance and creep rupture strength of iridium alloys is described in German published patent application DE 10 2005 032 591 A1. It involves doping with molybdenum, hafnium, and possibly rhenium, whereby the sum of molybdenum and hafnium is between 0.002 and 1.2 percent by weight. This allowed the time to rupture exposed to a load of 16.9 MPa to be increased more than two-fold as compared to undoped iridium.
International patent application Publication No. WO 2004/007782 A1 describes tungsten- and/or zirconium-containing iridium alloys for high temperature applications, which contain 0.01 to 0.5 percent by weight of further elements, such as molybdenum and hafnium and possibly 0.01 to 10 percent by weight ruthenium.
Japanese patent application publication no. JP 56-81646 A describes platinum-based jewellery alloys that contain calcium boride or boron to increase their strength, mainly their hardness, after a high temperature treatment, such as soldering.
BRIEF SUMMARY OF THE INVENTION
The presence of the tetravalent elements Zr and Hf in the iridium crucibles during the growth of some high-purity laser crystals is not desired, since they might lead to impurities in the crystal melt that have an adverse effect on the laser properties during later use. For this reason, it is an objective of the present invention to increase the creep rupture strength of iridium at high temperature while maintaining the ductility and processability of the material without using the elements mentioned above. Accordingly, it is advantageous for the respective material also to be free of titanium.
Surprisingly, it has been found that the addition of calcium and boron in the range of a few parts per million (ppm) increases the creep rupture strength at a temperature of 1,800° C. of iridium, doped as described, by 20 to 30% as compared to undoped iridium. It can be presumed that the same is also attained for iridium alloys as well as rhodium and the alloys thereof.
DETAILED DESCRIPTION OF THE INVENTION
The following examples illustrate the invention in more detail. As in the remainder of the description, specification of parts and percentages are by weight, unless stated otherwise.
COMPARATIVE EXAMPLE
8 kg of iridium were melted in a ZrO 2 crucible and poured into a water-cooled casting die. The iridium bar was subsequently forged at 1,600 to 1,700° C. and rolled in multiple steps to a final thickness of 1 mm. Before and between individual reduction stages, the bar or sheet was heated to 1,400° C. The hardness of the sheet was HV10=270. The samples for the stress rupture tests were taken from the rolled sheet.
A stress rupture curve was recorded for the iridium batch prepared as described using stress rupture tests at 1,800° C. In the test, the times to rupture were determined for applied structural loads between 6.7 and 25 MPa, and the values were subsequently approximated by a curve. The measured results are summarized in Table 1.
TABLE 1
Results of the creep rupture tests on pure
iridium (no doping with calcium and boron)
Time to
Elongation at
Elongation
Load [MPa]
rupture [hr]
rupture [%]
rate [sec −1 ]
6.7
1403.7
18.2
3.2 · 10 −8
8.3
385.9
22.3
1.2 · 10 −7
9.5
225.0
23.9
2.6 · 10 −7
10
95.0
36.9
6.4 · 10 −7
13
56.8
50.0
9.4 · 10 −7
16
17.48
22.4
1.6 · 10 −6
18
10.1
>50
1.4 · 10 −5
21
4.38
98.8
2.7 · 10 −5
23
1.67
13.5
1.5 · 10 −5
25
0.73
59.8
2.0 · 10 −4
The time to rupture varies in a range from 1,403.7 hr (approx. 58.5 days) at 6.7 MPa to 0.73 hr at 25 MPa and decreases with increasing load. While the elongation rate increases with increasing load, the elongation at rupture decrease shows no significant trend.
The following interpolated values for the creep rupture strength result from the creep rupture strength curve for predetermined times to rupture:
TABLE 2 Values from the creep rupture strength curve of the undoped Ir batch Time to Creep rupture strength Elongation rupture [hr] [MPa] rate [sec −1 ] 10 16.9 6.5 · 10 −6 100 11.0 5.6 · 10 −7 1000 7.2 4.9 · 10 −8
1st Inventive Embodiment
8 kg of iridium were melted in a ZrO 2 crucible and poured into a water-cooled casting die. Just before pouring, a pocket made of Pt foil (20 mm×20 mm×0.05 mm) filled with approx. 0.08 g (10 ppm) calcium and 0.08 g (10 ppm) boron was added into the melt.
The iridium bar was then forged analogously to the undoped iridium batch in the
Comparative Example and rolled to a final thickness of 1 mm. The hardness of the sheets was between HV10=226 and 242. Samples for the creep rupture strength tests and analyses were obtained from the rolled sheet.
A total of seven iridium batches was produced and tested by this means. GDL (glow discharge lamp) analyses were used to first determine the calcium and boron contents. The analytical results are shown in Table 3. The calcium and boron contents are close to identical for all batches. Note: Although calcium and boron were present in Batches A and B, the GDL analyses were not obtained.
TABLE 3
Results of the GDL analyses: Ca- and
B-contents of the doped Ir batches
Batch
Ca content [ppm]
B content [ppm]
A
—
—
B
—
—
C
4
3
D
4
3
E
4
3
F
4
3
G
5
3
Based on the creep rupture strength curve of the undoped Ir batch, creep rupture tests were carried out at a temperature of 1,800° C. with a structural load of 16.9 MPa. Compared to the time to rupture of the undoped Ir batch of 10 hr (Table 2), clearly higher times to rupture from 17.93 hr to up to 56.52 hr (Table 4) were attained for the doped batches.
Aside from the increase of the time to rupture, it was observed that the elongation at break also tended to be increased as compared to undoped iridium. The minimum value of the elongation at break measured was 23%, while a maximum value of 73% was attained. The elongation rates of the doped iridium batches were between 1.0×10 −7 and 3.4×10 −6 sec −1 .
TABLE 4 Results of the creep rupture tests at 1,800° C. at a structural load of 16.9 MPa Time to Elongation at Elongation Batch rupture [hr] break [%] rate [sec −1 ] A 32.85 55 2.7 · 10 −6 45.39 51 1.5 · 10 −6 33.47 44 1.2 · 10 −6 B 22.48 51 2.2 · 10 −6 17.93 68 2.2 · 10 −6 19.30 64 3.4 · 10 −6 C 50.65 65 1.3 · 10 −6 38.66 48 1.2 · 10 −6 56.52 73 1.0 · 10 −6 D 29.94 73 2.0 · 10 −6 18.88 56 2.2 · 10 −6 42.67 29 9.8 · 10 −7 E 54.89 46 8.3 · 10 −7 29.03 23 1.0 · 10 −7 34.89 35 1.2 · 10 −6 F 53.79 56 9.0 · 10 −7 35.66 39 1.1 · 10 −6 29.32 45 1.5 · 10 −6 G 19.31 57 2.1 · 10 −6 47.02 35 7.1 · 10 −7 43.83 38 1.2 · 10 −6
2nd Inventive Embodiment
A creep strength curve was recorded at a temperature of 1,800° C. for batch F from the 1st Inventive Embodiment, in addition to the creep rupture strength test at 16.9 MPa. The structural loads applied were in the range of 14 MPa to 25 MPa. The results are shown in Table 5.
TABLE 5
Results of creep rupture strength tests at various structural loads
Time to
Elongation at
Elongation
Load [MPa]
rupture [hr]
break [%]
rate [sec −1 ]
14.0
95.53
28
2.6 · 10 −7
16.9
39.59
47
1.2 · 10 −6
18.5
21.71
75
1.5 · 10 −6
20.0
14.43
69
2.4 · 10 −6
23.0
8.81
69
9.0 · 10 −6
25.0
3.44
76
1.7 · 10 −5
After determination of the creep strength curve, the following interpolated creep rupture strength values were obtained for predetermined times to rupture:
TABLE 6
Values from the creep rupture strength curve
of the calcium- and boron-doped Ir batch
Time to
Creep rupture strength
Elongation
rupture [hr]
[MPa]
rate [sec −1 ]
10
21.3
5.0 · 10 −6
100
14.3
3.1 · 10 −7
1000
9.5
1.8 · 10 −8
A comparison of these strength values to those of pure iridium at the same times to rupture shows that an increase of the creep rupture strength of at least 23% is attained at all times to rupture. The elongation rates of the interpolated values are clearly lower than those of pure iridium, especially at the lower structural loads. With regard to the elongations at break measured, almost three-fold higher values than for pure iridium are attained in some cases.
It will be appreciated by those skilled in the art that changes could be made to the embodiments described above without departing from the broad inventive concept thereof. It is understood, therefore, that this invention is not limited to the particular embodiments disclosed, but it is intended to cover modifications within the spirit and scope of the present invention as defined by the appended claims. | The addition of 0.5 to 30 ppm boron and 0.5 to 20 ppm calcium to iridium and the Zr- and Hf-free alloys thereof and rhodium and the Zr- and Hf-free alloys thereof surprisingly increases the creep rupture strength at high temperatures, in particular around 1,800° C. | 2 |
FIELD OF THE INVENTION
The present invention relates, generally, to bearing restraint devices for use in, for example, seismic isolation bearings for supporting various structures and apparatus, and, to bearing restraint devices in isolation platforms that isolate the structures and other loads, from ambient vibrations external to the platform.
SUMMARY OF THE INVENTION
Isolation bearings are used with, for example, bridges, buildings, computers, machines, delicate and/or dangerous equipment, and the like (hereinafter “structures”) to protect these structures from damage due to seismic phenomena. The isolation bearings (and platforms and floors containing such isolation bearings) are typically configured to support a specific load, i.e., the weight of the structure being supported. In this regard, it is desirable that a particular seismic isolation bearing be restrained in order to prevent failure of the bearing or instability of the structure being supported.
The conservative character of a seismic isolation bearing may be described in terms of the bearing's ability to absorb displacement energy caused by seismic activity or other external applied forces, and thus to cushion the structure being supported from such displacement. In this regard, features such as a rubber bearing body, leaf spring, coil spring, or the like may be employed to urge the bearing back to its original, nominal position following a lateral displacement caused by an externally applied force such as a seismic tremor. In this context, the bearing “conserves” lateral displacement energy by storing a substantial portion of the applied energy in its spring, rubber volume, or the like, and releases this stored energy upon cessation of the externally applied force to pull or otherwise urge the bearing back to its nominal original position.
Certain isolation bearings may have a laminated rubber bearing body, reinforced with steel plates. More particularly, thin steel plates are interposed between relatively thick rubber plates, to produce an alternating steel/rubber laminated bearing body. The use of a thin steel plate between each rubber plate in the stack helps prevent the rubber from bulging outwardly at its perimeter in response to applied vertical bearing stresses. This arrangement permits the bearing body to support vertical forces much greater than would otherwise be supportable by an equal volume of rubber without the use of steel plates.
Other isolation bearings may comprise steel coil springs combined with snubbers (i.e., shock absorbers). These bearings are often used to vertically support the weight of the structure; such bearings may be most suitable for the support of apparatus and machines. Coil springs, described in International Patent Publication WO 2004/007871, are generally preferable to steel/rubber laminates in applications where the structure to be supported may undergo an upward vertical force, which might otherwise tend to separate the steel/rubber laminate. Rubber bearings are typically constructed of high damping rubber, or are otherwise supplemented with lead or steel yielders useful in dissipating applied energy.
Metallic yielders, however, are disadvantageous in that they inhibit or even prevent effective vertical isolation, particularly in assemblies wherein the metallic yielder is connected to both an upper bearing plate and an oppositely disposed lower bearing plate within which the rubber bearing body is sandwiched.
Steel spring mounts of the type typically used in conjunction with apparatus and machines are generally unable to provide adequate energy dissipation, with the effect that such steel spring mounts generally result in wide bearing movements. Such wide bearing movements may be compensated for through the use of snubbers or shock absorbers to aid in absorbing the energy of the lateral displacement. However, in use, the snubber may impart to the bearing an acceleration on the order of, or even greater than, the acceleration applied to the machine due to seismic activity.
Another example of an isolation bearing is one using a rolling, approximately spherical rigid ball placed between rigid plates. It will be understood that such a rigid ball may itself be referred to as a bearing (such as a ball bearing), or the combination of the rigid ball and the supporting rigid plates may together be referred to as a bearing. In this description generally the word “bearing” shall be reserved for the entire assembly; however, in certain occasions the context may make clear that the ball itself is referred to as a bearing, such as through the use of terms such as “ball bearing”, “rolling bearing” or “spherical bearing”.
For example, one isolation bearing comprises a lower plate having a wholly or partly conical-shaped cavity and an upper plate having a substantially identical cavity with a rigid ball-shaped bearing placed therebetween. See e.g., Kemeny, U.S. Pat. No. 5,599,106. In another example, an isolation bearing comprises a lower plate having a wholly or partially spherical shaped cavity and an upper plate having a substantially identical cavity with a rigid ball-shaped bearing placed therebetween. In yet another example, such a device includes a bearing comprising a lower plate having a wholly or partially parabolic shaped cavity and an upper plate having a substantially identical cavity with a rigid ball-shaped bearing placed therebetween. Isolation platforms containing such bearings are disclosed in e.g., International Patent Publication No. WO/2004/007871 and US 2006/0054767; Isolation platforms comprising floors are disclosed in e.g., U.S. Pat. No. 7,290,375. Each of these publications and patents, and every other patent, patent application, and publication cited herein, is expressly and individually incorporated by reference herein in its entirety as part of this specification.
Isolation bearings of this type may in general include a bearing comprising a lower plate having, without limitation, a wholly or partially conical, spherical or parabolic shaped cavity, a cavity having a constant slope, or a cavity that is a combination of two or more of these shapes and, an upper plate having a cavity similar to that in the bearing plate, with a rigid ball shaped bearing placed therebetween. The lower plate rests or is fixed or placed on the ground, foundation, platform, support, or base surface, while the structure to be supported rests on the top surface of the upper plate, or the platform or surface which is held up by the isolator bearing or bearings. In this way, when external vibrations, such as seismic movements, occur the lower plate moves relative to the upper plate via the rolling of the spherical ball between the upper and lower plates. The structure supported is thus isolated from the external vibrations.
However, such devices are not without their own drawbacks. For example, depending on the size of the upper and lower plates, such bearings may have a limited range of mobility. That is, the amount of lateral displacement of the upper and lower plates relative to each other may be limited based on the size of the bearing.
Additionally, an isoation bearing may be unstable when used by itself. For example, when a large structure is placed on a relatively small isolation bearing, it may become more likely that the structure could tip and/or fall over. Obviously, with very large, heavy structures, or very delicate or dangerous structures, such failure could be catastrophic.
Similar to instability, the amount of load that any particular bearing can withstand can be limited by its size. Likewise, if the weight of the structure being supported is unevenly distributed, one section of either of the upper or lower plates may tend to bend or deflect more than another and the entire bearing structure could come apart.
Also, in isolation bearings and platforms containing rolling balls a severe shock, such as that caused by a strong seismic tremor, can cause such severe lateral displacement that the ball is ejected from the bearing, causing failure of the bearing.
To overcome such disadvantages there is a need for isolation bearings structures which are more stable (i.e., have less of a tendency to come apart), can withstand a greater load and are more easily integrated into the locations in which they are desired to be installed.
The present invention provides bearing restraints for use in isolation bearings and platforms for supporting various equipment and/or structures (“loads”). These bearings and platforms (including floors) assist in isolating the loads from vibrations (“noise”) generated by forces external to the bearing or platform. Generally, in accordance with various embodiments of the present invention, the bearings or platforms comprise upper or isolator plates and lower or bearing plates, having, without limitation, conical depressions, spherical depressions, parabolic depressions or depressions with combinations of these shapes. Preferably, although not necessarily, the upper plate and lower plate are substantially alike, or identical, in their opposing surfaces. In such isolation bearings or platforms the upper plate supports the above-mentioned load(s), and the lower plate contacting the floor, foundation, surface or area directly below the bearing or platform. Between the upper and lower plates, one or more rigid, spherical bearing is placed between the upper and lower plates within the depressions, thereby allowing the upper and lower plates to displace relative to one another. The bearing restraint devices of the present invention restrain the spherical bearings. The spherical bearings are generally made of metal, such as stainless steel, but may be made of any sufficiently rigid material, including a polymer such as a plastic, a hard rubber, and the like. Those of ordinary skill in the art will be aware that a hard, rigid ball, such as a stainless steel ball, making contact with a bearing surface of similar rigidity, will have a minimum of friction.
Alternatively, if a measure of dampening is desired, one or more ball and/or one or more bearing surface may be made to be more pliable (such as with a surface coating of rubber, plastic or the like; or by making all or part of the ball or bearing surface out of such a dampening material).
As lateral forces (e.g., in the form of seismic vibrations) are applied to a bearing, the upper plate is displaced laterally with respect to the lower plate, such that the rigid ball or balls therebetween roll and rotate freely and, if sufficiently hard and rigid, in an almost frictionless manner about their respective depressions or cavities. The ball or balls store the energy of the vibration as potential energy by being raised to higher elevations along the bearing surface, such that, the ball(s) remain in contact with the upper and lower plates and the upper and lower plates thus remain indirectly in contact with each other. Due at least in part to the conical, spherical, parabolic, or other raised shape of the lower and/or upper plates' bearing surfaces, the gravitational forces acting on the structure, and the structure's mass, produce a lateral force component tending to restore the bearing or platform to its original position, with the upper plate(s) being positioned substantially above the lower plate. Thus, in accordance with the present invention, restoring forces are achieved; for example, a conical depression (which yields a substantially triangular cross section) results in a substantially constant restoring force due to the linear hypotenuse of the triangle, while hemispherical or parabolic depressions (or mixtures of different types of depressions), yield restoring forces that vary with the distance of lateral displacement.
In the event that an outside force is strong enough, or long lasting enough, or if the bearing or platform lacks sufficient stability, the upper and lower plate of a bearing may be forcefully moved laterally with sufficient force that the ball or sphere may be thrown from the bearing, causing bearing failure. Such an eventuality could obviously be catastrophic for the structure, equipment, or other load borne by the bearing or plurality of bearings comprising the isolation platform or floor.
The stability of the bearing, floor or isolation platform is increased through the size of its “footprint” (its width versus its height) as compared to the weight distribution of the load. For example, when considering a platform, distances between the apices of a first pan structure (containing, for example, four bearings of the type discussed above) preferably have a ratio of less than 1.25 in relation to the height, width and/or depth of the payload. Additionally, preferably, no more than half of the total weight of the payload is in the upper half of the payload.
Various straps between the upper and lower plates may be attached, thereby allowing lateral displacement between the plates, but preventing unwanted separation of the plates. In addition to, or instead of these straps, one or more isolation bearing restraint may also be used, thereby freely permitting lateral displacement of the bearing due to the rolling sphere between the plates, but preventing bearing failure due to unwanted separation of the plates and/or separation or ejection of the rolling sphere or spheres themselves from between the upper and lower plates.
In certain embodiments, the bearing restraint of the present invention may comprise one or more, preferably two or more, or three or more, or four or more straps retaining one or more sphere substantially within the bearing surface of an upper and/or lower bearing plate or pan so that the sphere is free to roll within said bearing surface when the upper and lower plates or pans are laterally displaced.
Additionally, in accordance with various embodiments of the present invention, the retaining mechanism (such as, for example, retaining straps) may produce additional bearing damping effects, as well as providing retention of the spherical ball component.
Therefore, in a preferred embodiment, the present invention may comprise a bearing retention device that simultaneously prevents the upper and lower bearing surfaces from coming apart, while restraining the spherical bearing within the cavity formed by such surfaces.
In another preferred embodiment, an isolation platform for supporting a payload in accordance with the present invention comprises a first open pan structure having four upper plates with downward facing load-bearing surfaces, wherein the first open pan structure has a plurality of rigid members substantially in the same plane as, and connected to, the plates to form a quadrilateral. The first open pan structure has openings between each upper plate and each bearing surface comprising a recess with a central apex and a conical, spherical or parabolic surface, or combinations of such surfaces, extending from the apex continuously to a location substantially proximal to a perimeter of the recess, wherein distances between the apices of the recesses are preferably at least equal to distances antipodal points of a footprint of the payload. A second open pan structure substantially identical to said first open pan structure (and where the plates are lower plates) is also provided and wherein said first and second open pan structures are positioned such that the bearing surfaces of correspondingly located upper and lower plates of the first and second open pan structures face each other and define four cavities therebetween, each cavity containing at least one rigid ball each.
Said at least one rigid ball located in each cavity is retained by a “cage” or “sleeve” which permits the ball to rotate freely in any direction while restraining the ball within the cavity by means of a plurality of straps that keeps the cage substantially centrally located within its cavity. Preferably, one or more of the straps comprising the plurality of straps is elastic; in a preferred embodiment, each strap of the plurality of straps is elastic. In another preferred embodiment said plurality of straps comprise a polymeric material. In another preferred embodiment, a top portion of the cage is joined to at least four straps, with one or more strap joined at the distal end to a corner of an upper plate located on the first open pan structure. In this embodiment, a bottom portion of the cage is joined to at least four straps, with one or more strap joined at the distal end to a corner of a lower plate located on the second open pan structure.
In the embodiment of the invention just discussed, the first and second open pan structures of the isolation platform are inherently movably fastened together with the (preferably elastic) straps of the described ball restraint device. In this way that the ball restraint device simultaneously limits displacement of the first open pan structure relative to the second open pan structure in a vertical plane and reduces displacement in a substantially horizontal plane of the first (upper) open pan structure relative to the second (lower) open pan structure.
Further still, in accordance with various embodiments of the present invention, the first pan structure (or upper bearing plate may be configured to move in the horizontal plane without moving relative to the second pan structure (or lower bearing plate) in the vertical plane by more than a pre-selected factor relating to the maximum possible or desired horizontal displacement relative to the second pan. Similarly, the first pan structure (or upper bearing plate) may be configured to move in the horizontal plane when the second pan structure (or lower bearing plate) is moving at a rate of up to a pre-selected forces without the first open pan structure moving more than a pre-selected distance in the horizontal plane and relative to the second open pan structure. In each of these cases, such configuration can be rendered by the length of straps comprising the bearing restraint device, the elasticity of the straps comprising the bearing restraint device, or a combination of such methods. Likewise, in another preferred embodiment, one or more spherical ball bearings in an isolation platform for supporting a payload in accordance with the present invention are restrained in a bearing restraint device. The bearing restraint device comprises a cage or sleeve; this cage or sleeve further comprises a first sleeve structure with downward facing, partly spherical or partly concave sleeve inner surface having substantially the same curvature as that of the spherical ball and a substantially identical second sleeve structure with upward facing partly spherical or partly concave inner sleeve surface having substantially the same curvature as that of the spherical balls.
In a preferred embodiment, the downward facing opening of the first sleeve structure has a circumference slightly smaller than the maximum circumference of the spherical ball, and the upward facing opening of the second sleeve structure has a circumference slightly smaller than the maximum circumference of the spherical ball, such that the first and second sleeve structures may be joined with upward and downward facing openings opposing, and with the spherical ball held therewithin.
In this embodiment, the first open sleeve structure has a substantially circular opening on the opposing side of the sleeve from that of the downward facing opening, in which the substantially circular opening is slightly larger than the circumference of a section of the circle ball at the same height from the equator of the ball as the sleeve is thick. Similarly, the second open sleeve structure has a substantially circular opening on the opposing side of the sleeve from that of the upward facing opening, in which the substantially circular opening is slightly larger than the circumference of a section of the spherical ball at the same height from the equator of the ball as the sleeve is thick.
In use, the first and second sleeve structures are positioned in a manner such that the partly spherical or partly concave sleeve inner surfaces of the first and second sleeve structures encase the rigid ball therebetween and wherein the ball, while being retained in the sleeve, is free to rotate within the sleeve and roll on the lower and/or upper plates of the bearing or isolation platform.
In an embodiment of the invention, the partly spherical or partly concave inner surface of the first and second open sleeve surfaces may be further described as defining a partly spherical bore therethrough with a circular opening having a maximum diameter located on the side of the sleeve having the upward or downward facing opening that is slightly larger than the circumference of the spherical ball encased, and a circular opening having a minimum diameter located on the side of the sleeve opposing the upward or downward facing opening that is between about 0.5% to 20% smaller than the equatorial circumference of the rigid ball, such that the rigid ball encased within the sleeve surfaces is free to rotate in any direction within the sleeve surfaces and roll on the lower and/or upper plates of the bearing or isolation platform.
The sleeve structure may alternatively be described as defining a cross-section of a hollow sphere that encases the rigid ball bearing. Preferably, the first and second sleeve structures are fastened to each other via nut and bolt type fasteners, or one or more barb-type male projections on the first sleeve structure which fit into a female receptacle on the second sleeve structure, though alternative means of affixing the first and second sleeve structures together may include gluing, riveting, welding, brazing or the like. The bearing restraint further comprises elastic straps connecting the sleeve structure, for example, at points proximal to or where the first and second sleeve structures are fastened to each other, to points in the rim proximal to or at the perimeter of each the upper plate and lower plate of the bearing or isolation platform, or, when describing an isolation platform, proximal to or at points in the upper and lower frameworks of the platform that the upper and lower bearing plates are fastened to.
The elastic straps are fastened to the assembled sleeve structure and the plates of the bearing or isolation platform and/or the upper and lower platform frameworks preferably via nut-bolt type fasteners, though the straps may be tied, looped, riveted or otherwise fastened by any other effective alternative means of fastening.
In the absence of any external vibration, the elastic straps are preferably kept slightly loose. In the event of a vibration, however, the straps stretch as required and aid in movably maintaining the first and second plate or pan structures in association with each other. Additionally, the bearing retaining device of the present invention simultaneously limits lateral and vertical displacement of the first plate or pan structure relative to the second plate or pan structure.
In an embodiment, the bearing restraint device of the present invention retains the rigid ball or sphere within the assembled sleeve, which is tethered by a plurality of elastic straps to the upper and lower plates or pans. The rigid ball is free to rotate in any direction while being restricted, in a strong vibration, within the circumference or area of the bearing plates of each the upper and lower bearing portions. In this way, the bearing restraint device of the present invention helps maintain bearing integrity during a seismic event.
In one embodiment of the present invention, the elastic straps of the restraint device do not produce damping effects. In another embodiment of the present invention, the ball bearing restraint device prohibits the ball bearing from re-centering when there is any vertical movement of the upper platform as it impacts the rim at the perimeter of the plates.
In yet another embodiment of this invention, the bearing and isolator plates are rectangular or square in shape.
In other embodiments of the present invention, exemplified in the Figures hereof, the depressions and/or cavities in the lower bearing and isolator plates may have varied surfaces defining cavities, recesses, grooves, or combinations of grooves, of various shapes.
BRIEF DESCRIPTION OF THE DRAWINGS
Additional aspects of the present invention will become evident upon reviewing the non-limiting embodiments described in the specification and the claims taken in conjunction with the accompanying figures, wherein:
FIG. 1A is a top view of an embodiment of the bearing restraint device of the present invention.
FIG. 1B is a top view of an elastic strap comprised in the embodiment of the bearing restrain device shown in FIG. 1A .
FIG. 1C is a side view of the elastic strap shown in FIG. 1B .
FIG. 2 is a view of a ball in cone isolation bearing in which the bearing restraint device of the present invention may be used.
FIG. 3 is a partially exploded view of an isolation bearing in which an embodiment of the bearing restraint device of the present invention has been installed.
FIG. 4 is an alternative exploded perspective of the isolation bearing of FIG. 3 , with bearing retention device installed.
FIG. 5A is a view of a “female” portion of one embodiment of a sleeve system for retaining a spherical ball.
FIG. 5B is a top view of a “male” portion of one embodiment of a sleeve system for retaining a spherical ball.
FIG. 6 is an exploded view showing a spherical bearing contained within the male and female sleeve portions shown in FIG. 5A and FIG. 5B , and the method of attachment of one elastic strap.
DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS
In accordance with various exemplary embodiments of the present invention, FIG. 1 shows a top view of an embodiment of the isolation bearing retainer of the present invention, in disassembled form. The isolation bearing retainer 100 is provided to filter vibrations and prevent a load placed upon the top plate or platform of an isolation bearing or isolation platform to be cushioned from movement due to such vibrations. Preliminarily, it will be appreciated by one skilled in the art that the following description is of exemplary embodiments only and is not intended to limit the scope, applicability, or various possible configurations of the invention in any way. Rather, the following description merely provides convenient illustrations for implementing various embodiments or alternative configurations of the invention. For example, various changes may be made in the design and arrangement of the elements described in the exemplary embodiments herein without departing from the scope of the invention as set forth in the appended claims.
That being said, the isolation bearing retainer of FIG. 1 comprises a spherical bearing 103 surrounded by and retained by a top sleeve portion 101 and a bottom sleeve portion (not shown in this view). The top and bottom sleeve portions, when assembled, form a united sleeve structure surrounding and retaining a volume including the equatorial region of the spherical bearing, while permitting these spherical bearing 103 to rotate in any direction. The top sleeve portion 101 has four “ears” 105 formed into its circumference at angles of approximately 90° from each other. At each ear a top portion elastic strap 107 is affixed; the bottom sleeve portion (not shown in this figure) also comprises four ears interacting with the ears of the top portion and positioned approximately 90° from each other around its circumference; to each of these ears a bottom portion elastic strap 107 is affixed. Other than the location at which the elastic strap is fixed to a portion of the sleeve structure, top portion and elastic strap and the bottom portion elastic strap are identical.
FIG. 1B shows a close-up top view of an embodiment of the elastic strap ( 107 , 109 ) used in the present invention. The elastic strap may be thickened or rounded in one dimension, flat portion 111 located at each end. The thickened or rounded portion 111 has a hole 113 through which a bolt or projection can be used to affix the elastic strap at opposing ends. Those of ordinary skill in the art will appreciate that the thickened portion 111 in this embodiment of the elastic strap need not be rounded but may be any suitable flattened shape.
FIG. 1C shows a close-up, side view of the elastic strap shown in FIG. 1B . In this view it is clear that the second or rounded, flat portion 111 , visible in FIG. 1B , is flat when viewed from the side. In this embodiment of the invention, the strap itself is approximately round in cross section, and does not vary from top to side views.
FIG. 2 shows an embodiment of a ball and cone isolation bearing 210 within which the isolation-bearing retainer 100 of the present invention may be used. The main components of the isolation bearing are upper load plate 211 A, lower load plate 211 B, spherical bearing 212 , conical upper 217 and lower 215 bearing surfaces, a circumference located around and circumscribing upper and lower bearing surfaces 216 , holes for anchor bolting 213 , and anchor bolts 214 . Those of ordinary skill in the art will appreciate that the bearing surfaces need not be conical (or entirely conical), and may have wholly or partly hemispherical or parabolic curved bearing surfaces, or combinations of various shapes as bearing surfaces.
FIG. 3 shows a ball in cone isolation bearing similar to that depicted in FIG. 2 with the isolation bearing retaining system in place. In this figure, the bearing is shown in “exploded” configuration, whereby the top and bottom load plates 211 a , 211 b , respectively, are separated to show the spherical bearing 212 encased in the top sleeve portion 101 and bottom sleeves portion 117 . The spherical bearing 212 is positioned between upper load plate 211 a , having conical upper bearing surface 217 , and lower load plate 211 b , having conical lower bearing surface 215 . Proximal segments of top portion elastic straps 107 are shown affixed to top sleeve portion 101 , while proximal segments of bottom portion elastic straps 109 are affixed to bottom sleeve portion 117 . The distal ends of the top portion elastic straps are affixed to the top load plate, and the distal ends of the bottom portion elastic straps are affixed to the bottom load plate. Those of ordinary skill in the art will appreciate that the holes in the distal end of the elastic straps may be aligned with the holes for anchor bolting 213 , and anchor bolts 214 in the upper and lower load plates.
In FIG. 4 , the bearing is again shown in “exploded” configuration in a different view, whereby the top and bottom load plates 211 a , 211 b , respectively, are separated to show the spherical bearing 212 encased in the top sleeve portion 101 and bottom sleeves portion 117 . In this case a top portion elastic strap 107 is shown with a distal end 111 in the foreground and fastened with a screw 301 to an outside surface of top load plate 211 a . Similarly a bottom portion elastic strap 109 is shown with a distal end 111 in the foreground and fastened with a screw 301 to an outside surface of bottom load plate 211 b . It will be understood that the elastic straps may be affixed to any other convenient location on the upper and lower plates or platforms of the seismic bearing; and that such location is not limited to the outside surface of a plate or platform.
FIG. 5A shows an embodiment of one of the portions of the sleeve structure assembly. This portion (which may be used as either a top portion or a bottom portion) comprises a polymeric or metallic (preferably polymeric) female annulus 413 with 4 ears 412 , with each ear 412 located approximately 90° from each other ear around the outer circumference 409 of the annulus. Each ear comprises a raised spacer portion 401 having a hole 403 through the center of it. The inside of the annulus comprises a band 405 having an inner circumference slightly less than the maximum (equatorial) circumference of the spherical bearing. In preferred embodiments the band 405 is curved or tilted to conform, either approximately or closely, with the curvature of the spherical bearing.
FIG. 5B shows an embodiment of another one of the portions of the sleeve structure assembly designed to match and mate with the portion depicted in FIG. 5A . This portion (which also may be used as either a top portion or a bottom portion) comprises a polymeric or metallic (preferably polymeric) male annulus 415 with four ears 412 containing posts 411 and each ear located approximately 90° from each other ear around the circumference of the annulus. Each post 411 is approximately cylindrical in shape and has a circumference slightly less than the circumference of the holes 403 found in corresponding positions on sleeve portion 413 shown in FIG. 5A , thus permitting the two sleeve portions to be fitted and joined together. As in the portion shown in FIG. 5A , the inside of the annulus comprises a band 405 having an inside circumference slightly less than the circumference of the spherical bearing. In certain embodiments the band 405 may be curved or tilted to conform, either approximately or closely, with the shape of a sub- and/or super-equatorial region of the spherical bearing.
As shown in FIG. 6 when the two portions depicted in FIGS. 5A and 5B are fitted together with the spherical bearing located between them, posts 411 on male sleeve portion 415 are fitted through the hole 113 at an end 111 of one or more elastic strap 107 , 109 before being inserted into the hole 403 in the “female” sleeve portion 413 . In this way the elastic straps can be affixed to the bearing retention sleeve.
It will be understood that, in accordance with various embodiments, rather than the conical load bearing surfaces shown in the foregoing examples, each of the plates may comprise corresponding concave, generally conical surfaces or spherical or parabolic surfaces (recessed surfaces) which create a plurality of conical or spherical or parabolic cavities therebetween. An example of such surfaces can be seen in the figures and disclosure of, e.g., Kemeny, U.S. Patent Publication 2006/0054767, previously incorporated by reference herein as part of the disclosure of this patent application. Generally speaking, it should be appreciated that any suitable combination of radial or linear surfaces may be employed in the context of recesses in accordance with the present invention. In addition, the surfaces may have, for example, a constant continuous slope or a varying continuous slope.
In the case of a platform comprising more than one isolation bearing, or a complex isolation bearing comprising more than one spherical bearing (such as more than one ball bearing), the upper isolation platform has a plurality of downward-facing, conical or spherical or parabolic, rigid bearing surfaces or surfaces with combinations of such shapes. For example, the lower plate or platform may be secured to a foundation or other support surface (e.g., mechanically (such as by bolting or screwing) or by gravity and the weight of platform itself) for supporting the structure to be supported, and has a plurality of upward-facing, conical or spherical or parabolic, rigid bearing surfaces or surfaces with or combinations of such shapes disposed opposite downward-facing, conical, rigid bearing surfaces. Thus, the downward and upward bearing surfaces define a plurality of bearing cavities between said upper and lower plates, within which a plurality of rigid spherical balls are interposed between said downward and upward bearing surfaces.
With further particularity in the presently described exemplary embodiment, the downward and upward bearing surfaces may comprise central apices having the same curvature as that of the rigid spherical balls to prevent movement of the apparatus in the event of slight external forces. However, it may be desirable that the apices are shallow, or (in alternate embodiments even absent) so as to prevent resonance and harmonic disturbances when the apparatus is active after a significant vibration. Additionally, the surfaces may have recess perimeters surrounding the bearing surfaces such that the bearing surface connects the central apices and recess perimeters with either continuous (linear or curved) or varying slope. Thus, the curvature of the spherical balls and the downward and upward bearing surfaces are configured such that as the spherical balls and upper and lower plates displace laterally relative to one another, vertical displacement of upper and lower plates is generally less than lateral displacement.
Although the foregoing invention has been described in detail for purposes of clarity of understanding, it will be obvious that certain modifications may be practised within the scope of the appended claims. All publications and patent documents cited herein are hereby incorporated by reference in their entirety for all purposes to the same extent as if each were so individually denoted. | Bearing retention devices and methods for their use in isolation bearings such as seismic bearings. In preferred embodiments, the invention includes a sleeve structure assembly secured by a plurality of elastic straps to upper and lower plates or pans of a rolling ball isolation bearing. The sleeve component is structured to retain the rolling ball within the circumference or area of the bearing plates of each the upper and lower bearing portions of the bearing while permitting the ball to freely roll in any direction during a seismic event. | 4 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a tension mechanism in a power slide device for vehicle sliding door, and in particular, it relates to an improved tension roller for tension mechanism.
2. Description of the Related Art
In general, a conventional power slide device for vehicle sliding door comprises a wire drum rotated by motor, and a door-opening cable connected to the wire drum, and a door-closing cable connected to the wire drum. When the wire drum is rotated in a door-opening direction, the door-opening cable is wound up, and at the same time, the door-closing cable is pulled out, so that the sliding door is slid in the door-opening direction. On the contrary, when the wire drum is rotated in a door-closing direction, the door-opening cable is pulled out, and at the same time, the door-closing cable is wound up, so that the sliding door is slid in the door-closing direction.
The wire cable is retained at an appropriate tension by a tension mechanism. The tension mechanism comprises a pair of tension rollers biased in such a manner as to be adjacent to each other by elasticity of the springs.
FIG. 1 is a schematic view showing a relation among a wire drum A, a wire cable B, and a tension roller C. A typical thickness of the wire drum A along a drum shaft D is approximately 20 mm, and when the wire drum A rotates, the wire cable B is wound up (or pulled out), moving upward or downward guided by a helical engaging groove E of the wire drum A.
Since the typical tension roller C is a bobbin type roller with a short diameter in center, even if the wire cable B moves upward or downward in response to rotation of the wire drum A, the tension roller C substantially keeps the wire cable B at the center. The problem of this structure has been that the wire cable B is unmovable upward and downward relatively to the tension roller C. Hence, when the wire cable B moves upward or downward for the wire drum A, the wire cable B between the wire drum A and the tension roller C deviates widely from a right angle with the drum shaft D of the wire drum A, thereby often causing an engaging trouble between the wire cable B and the engaging groove E. The engaging trouble becomes serious as the distance between the wire drum A and the tension roller C becomes shorter. Consequently, the bobbin type tension roller C has been disposed at a place away from the wire drum A, thereby inviting a large size of the power slide device.
In contrast to this, as shown in FIG. 2 , a tension roller C′ which is formed into a cylindrical roller having the same diameter from the top to the bottom is also publicly known. A cylindrical tension roller C′ attempts at miniaturization of the power slide device by forming the tension roller C′ at approximately 20 mm in accordance with the thickness of the wire drum A so that the space between the tension roller C′ and the wire drum A is made short.
The device of FIG. 2 has a problem in that a “cable rubbing noise” is generated when the wire drum A is rotated. A cause of the noise generation will be described below.
By the rotation of the wire drum A, when the cable B, for example, moves upward for the wire drum A, the upward movement of the cable B relatively to the tension roller C′ is slightly delayed. Hence, an angle X between the cable B and the lower side surface of the roller C′ exceeds more than 90 degrees. Then, a downward external force as shown by an arrow a is applied to the cable B in the vicinity of the roller C′ so that the upward movement of the cable B in the vicinity of the roller C′ is further delayed. As a result, the wire cable B rubs against an angular portion of the engaging groove E of the wire drum A, thereby generating the noise.
Further, the cable B in the vicinity of the roller C′ abruptly moves in order to catch up on the delay of the upward movement, thereby causing the noise.
SUMMARY OF THE INVENTION
Therefore, an object of the present invention is to provide a tension roller of the power slide device having controlled the generation of noises by allowing the upward or downward movement of the cable for the tension roller to be smoothly performed.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic view showing a relation among a wire drum, tension roller, and wire cable of a conventional device;
FIG. 2 is a schematic view showing a relation among another conventional wire drum, tension roller, and wire cable;
FIG. 3 is a side view of a vehicle including a power slide device of the present invention;
FIG. 4 is a development of the power slide device and the slide door;
FIG. 5 is a partially abbreviated sectional view of a tension mechanism of the power slide device;
FIG. 6 is a partially abbreviated sectional view of the tension mechanism;
FIG. 7 is an explanatory view of the operation of the tension mechanism; and
FIG. 8 is a table showing the experiment result of the tension mechanism according to the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
A first embodiment of the present invention will be described below with reference to the drawings. FIG. 3 shows a rough relation between a power slide device 10 of the present invention and a slide door 11 for vehicle which slides in a door-closing direction and a door-opening direction by the power slide device 10 . FIG. 4 shows a developed relation between both the device 10 and the door 11 .
The slide door 11 is slidably attached to a vehicle body 12 , and slides in the backward and forward direction of the vehicle body 12 along a guide rail 13 provided on the vehicle body 12 . The slide device 10 has a motor 14 and a wire drum 15 rotated by the motor 14 , and these elements are attached to a base plate 16 fixed to the vehicle body 12 .
The wire-drum 15 is connected with a pair of wire cables 17 , that is, tip end sides of the door-opening cable 17 A and the door-closing cable 17 B, respectively. When the wire drum 15 rotates in the door-opening direction, the door-opening cable 17 A is wound up, and the door-closing cable 17 B is pulled out, and the slide door 11 is slid in the door-opening direction. When the wire drum 15 is rotated in the door-closing direction, the door-opening cable 17 A is pulled out, and the door-closing cable 17 B is wound up, and the slide door 11 is slid in the door-closing direction.
The other end of the door-opening cable 17 A is connected to a bracket 19 of the slide door 11 through a rear side pulley 18 pivotally mounted on the vehicle body 12 . Similarly, the other side of the door-closing cable 17 B is connected to the bracket 19 through a front side pulley 20 pivotally mounted on the vehicle 12 .
The base plate 16 is provided with a tension mechanism 21 retaining a tension of the wire cable 17 at an appropriate pressure. The tension mechanism 21 has a pair of tension rollers 22 and 23 abutted against by the cables 17 A and 17 B. The tension shafts 24 and 25 of the tension rollers 22 and 23 are slidably attached to elongated slots 26 and 27 formed on the base plate 16 . The tension rollers 22 and 23 are biased in such a manner as to be mutually approached by elastic force of the tension spring 28 . Reference numeral 29 denotes a cover case of the tension mechanism 21 .
Both upper and lower ends of the tension roller 22 , as shown in FIG. 6 , are formed with flanges 22 A and 22 A, and a cable abutting surface 22 B between the flanges 22 A and 22 A is formed on an inclined surface which becomes gradually shorter in diameter from the bottom to the top. Similarly, both upper and lower ends of the tension roller 23 are formed with flanges 23 A and 23 A, and the cable abutting surface 23 B between the flanges 23 A and 23 A is formed on an inclined surface which becomes gradually longer in diameter from the bottom to the top. In the present embodiment, the cable abutting surface 22 B and the cable abutting surface 23 B are inclined mutually in a reverse direction, and when the upper portion of one abutting surface becomes long in diameter, the upper portion of the other abutting surface becomes short in diameter. This depends on an attachment relation among the wire drum 15 , the door-opening cable 17 A, and the door-closing cable 17 B to be described later.
FIG. 7 shows a relation between the wire drum 15 and the tension rollers 22 and 23 in the present invention. The door-opening cable 17 A and the door-closing cable 17 B are wound around the engaging groove 30 of the wire drum 15 . When the slide door 11 is in a door-closed position, the door-opening cable 17 A is pulled out from the engaging groove 30 of the wire drum 15 , and the door-closing cable 17 B is wound up by the engaging groove 30 of the wire drum 15 . At this time, in the embodiment of FIG. 7 , the relation is established such that both the door-opening cable 17 A and the door-closing cable 17 B are positioned at the bottom side of the wire drum 15 . When the wire drum 15 is rotated in a door-opening direction about the drum shaft 31 as a center, the door-opening cable 17 A, while being wounded, is guided to the engaging groove 30 , and moves upward as shown by an arrow b, and the door-closing cable 17 B already wounded around the engaging groove 30 , while being pulled out, similarly moves upward as shown by an arrow c (the relation is reversed at the door-closing rotation of the wire drum). Further, both the door-opening cable 17 A and the door-closing cable 17 B move from the long diameter side to the short diameter side of the tension rolls 22 and 23 when wound up by the drum 15 . Hence, in the present embodiment, the cable abutting surface 22 B and the cable abutting surface 23 B incline in a mutually reversed direction.
However, the relation between the wire drum 15 and the cables 17 A and 17 B becomes sometimes such that, when the wire drum 15 rotates, depending on the shape of the engaging groove 30 of the wire drum 15 , one of the cables moves upward and the other moves downward. In this case, inclinations of the cable abutting surface 22 B and the cable abutting surface 23 B are set in the same direction, and the cable to be wound up is changed so as to move toward the short diameter of the abutting surface.
(Operation)
When the slide door 11 is at the door-closed position, the door-opening cable 17 A has been pulled out from the engaging grove 30 of the wire drum 15 , and the door-closing cable 17 B has been wound up by the engaging groove 30 of the wire drum 15 . In this state, when the wire drum 15 is rotated in the door-opening direction, in the embodiment of FIG. 7 , the door-opening cable 17 A, while being wound up, is guided to the engaging groove 30 , and moves upward, and further, the door-closing cable 17 B already wound up by the engaging groove 30 , while being pulled out, similarly moves upward.
At this time, since the door-opening cable 17 A moves toward the upper side (short diameter side) of the cable abutting surface 22 B when wound up, and the angle X between the lower side surface of the cable abutting surface 22 B of the tension roller 22 and the cable 17 A is below 90 degrees due to the inclination of the abutting surface 22 B, when the door-opening cable 17 A moves upward relatively to the tension roller 22 , the delay of the upward movement for the tension roller 22 is controlled, and the door-opening cable 17 A to be wound up is smoothly wound up.
FIG. 8 shows a measurement result of the “cable rubbing noise” according to the angle of the cable abutting surface 22 B of the tension roller 22 . At the cable pulling out side, no matter whatever angle the cable abutting surface has, no generation of sounds that becomes a problem has been recognized. However, at the cable winding side, when the angle of the cable abutting surface is zero degree (when the cable abutting surface 22 B is in parallel with the drum shaft 31 ), the generation of sounds has been recognized. When the inclination is made three degrees, the noise has been considerably controlled. In case the angle is five degrees, no generation of noises has been substantially recognized. The suitable angles of the cable abutting surfaces 22 B and 23 B, in spite of the slight fluctuation depending on the factor such as the distance and the like between the tension rollers 22 and 23 and the wire drum 15 , are desirable to be three to seven degrees. | A power slide device includes a first cable connected to a wire drum and moving in a first direction when wound up by the wire drum, a second cable connected to the wire drum and moving in a second direction when wound up by the wire drum, a first tension roller having a first abutting surface abutting against the first cable, and a second tension roller having a second abutting surface abutting against the second cable. The first abutting surface is taken as an inclined surface becoming gradually shorter in diameter toward the first direction, and the second abutting surface is taken as an inclined surface becoming gradually shorter in diameter toward the second direction. | 4 |
FIELD OF THE INVENTION
[0001] This invention relates generally to electronic messaging, and more specifically to a method for detecting tampering with an electronic message.
BACKGROUND OF THE INVENTION
[0002] There are known redundancy techniques for guarding against malicious alterations of electronic message files such as electronic mail. A common method employed to determine whether a message has been altered in transit between the sender and recipient is to add message redundancy to the message file. Such redundancy may take the form of a cyclic redundancy check (CRC) or a hash of the message. In such systems, prior to transmission of the message from the sender's communication device, an encoder calculates a CRC or hash value based on the content of the message, and appends this value to the end of the message file. The message, together with the hash value, is then encrypted. The encrypted message with the appended CRC or hash value is then transmitted via a wireless or fixed-link network to the recipient's communication device.
[0003] When the message is received by the recipient's communication device, the message is decrypted. The CRC or hash value may then be found by the recipient's communication device at the end of the message. The recipient's communication device is able to calculate a CRC or hash value from the received message content, and then compares the calculated value with the redundancy value that was transmitted with the message. If the values match, then the message file is presumed to have been unaltered before receipt by the recipient's communication device. If the values do not match, then the message is determined to have been deliberately or accidentally altered.
[0004] The structure of such electronic message files is static; in other words, it is generally known that redundancy measures such as those described above append the CRC or hash value at the end of the message file. It is therefore possible for a party intercepting an electronic message before it is received by the message recipient to locate the redundancy value at the end of the intercepted message content. Once the redundancy value is located, an intercepting party may maliciously alter the content of the message while preserving the redundancy value. Alternatively, an intercepting party may alter the content of the message, recalculate the redundancy value, and replace the old hash value with the newly recalculated value. In such a case, the redundancy technique is rendered ineffective as the recipient is therefore unable to determine from the redundancy value comparison that the message has been tampered with when it is finally received by the recipient's communication device.
[0005] Accordingly, it is desirable to provide a method for adding redundancy checks to an electronic message such that deliberate tampering is discouraged, and is easier to detect.
SUMMARY OF THE INVENTION
[0006] According to one aspect of the invention, a method is provided for a sending communication device to provide redundancy to an electronic message to be sent to a recipient communication device, the method comprising the steps of determining a redundancy value for the electronic message to be sent, determining a locating value, the locating value being defined such that the value varies for different electronic messages and being defined such that the locating value may be determined by the recipient communication device for each electronic message sent to it, placing the redundancy value in the electronic message at one or more locations determined by the locating value, and encrypting the electronic message including the redundancy value. In a further aspect of the invention, prior to the step of placing the redundancy value in the electronic message at one or more locations determined by the locating value, the electronic message is formatted as a series of message blocks, and formatting the redundancy value as one or more redundancy value blocks. A further aspect is that the step of determining a locating value comprises the step of determining the value of a characteristic of the electronic message. Yet another aspect is that the step of encrypting the electronic message including the redundancy value comprises the step of assigning a session key to the electronic message. In various embodiments of the invention, the step of determining the value of a characteristic of the electronic message may comprise the step of determining the number of bits of a predetermined value in the session key, or the step of determining the value of a characteristic of the electronic message further comprises the step of determining the parity of the number of bits.
[0007] In another aspect of the invention, the step of placing the redundancy value in the electronic message at one or more locations determined by the locating value comprises the steps of selecting a message block from the series of message blocks based on the locating value, and inserting at least one of the one or more redundancy value blocks in a location defined in relation to the selected message block, and optionally that the step of determining a locating value comprises the step of determining the value of a characteristic of one or more predetermined message blocks.
[0008] Yet another aspect of the invention provides a communication device for sending a message to a recipient communication device, comprising program code operative to define a message; program code operative to determine a redundancy value for the message; program code operative to determine a locating value, the locating value being defined such that the value varies for different messages and being defined such that the locating value may be determined by the recipient communication device for each message sent to it; program code operative to place the redundancy value in the message at one or more locations determined by the locating value; and program code operative to encrypt the message including the redundancy value. In further aspects, the locating value is the value of a selected characteristic of the message. In another aspect, the program code is also operative to encrypt the message using a session key, and the selected characteristic of the message may be the number of bits of a predetermined value in the session key or the parity of the number of bits of a predetermined value in the session key.
[0009] In a further aspect, the communication device further comprises program code operative to format the message as a series of message blocks and program code operative to format the redundancy value as one or more redundancy value blocks, such that the program code operative to place the redundancy value in the message at one or more locations determined by the locating value is operative to identify one of the series of message blocks, and then insert at least one of the one or more redundancy value blocks in a location defined in relation to the identified one of the series of message blocks. In another aspect, the program code is also operative to encrypt the message using a session key, or operative to derive a value from a characteristic of a specified block in the series of message blocks as the locating value, locate an identified message block based on the locating value, and insert at least one of the one or more redundancy value blocks in a location defined in relation to the identified message block.
[0010] Yet another aspect of the invention provides a communication device for decrypting an encrypted message, the message comprising a plurality of message blocks and one or more redundancy value blocks placed among the plurality of message blocks according to a locating value, the locating value being defined such that the locating value varies for different messages, the communication device comprising program code operative to decrypt the encrypted message, program code operative to locate the one or more redundancy value blocks in the message based on the locating value, program code operative to obtain a received redundancy value from the one or more redundancy value blocks, program code operative to determine a calculated redundancy value from the plurality of message blocks, and program code operative to compare the received redundancy value with the calculated redundancy value.
[0011] In a further aspect of the invention, the communication device is provided with program code operative to locate the one or more redundancy value blocks in the message based on the locating value comprising code to determine or receive the locating value, identify one of the plurality of message blocks using the locating value, and identify the location of at least one of the one or more redundancy value blocks in relation to the location of the identified one of the plurality of message blocks within the message.
[0012] In a still further aspect of the invention, a method is provided for determining the reliability of a received encrypted message, the message comprising a plurality of message blocks and one or more redundancy value blocks placed among the plurality of message blocks according to a locating value, the locating value being defined such that the locating value varies for different messages, the method comprising the steps of decrypting the encrypted message to obtain a message; locating the one or more redundancy value blocks in the message based on the locating value; obtaining a received redundancy value from the one or more redundancy value blocks; determining a calculated redundancy value from the plurality of message blocks; comparing the received redundancy value with the calculated redundancy value; and determining that the message is not reliable if the received redundancy value and the calculated redundancy check value are not equal.
[0013] In a further aspect, method further comprises the steps of identifying one of the plurality of message blocks using the locating value; and identifying the location of at least one of the one or more redundancy value blocks in relation to the location of the identified one of the plurality of message blocks within the message.
[0014] In still a further aspect of the invention, a communication device is provided for sending a message to a recipient device over a network, the communication device comprising a processor, a memory, an interface to allow input of a message, a network connection, a messaging module operably connected with the processor and the memory to receive message input using the interface, the messaging module being configured to format the message as a series of message blocks, calculate a redundancy value from the message and format the redundancy value into at least one redundancy value block, determine a locating value such that the locating value varies for different messages and may be determined by the recipient device for each message sent to it, placing the at least one redundancy value block in the series of message blocks according to a predetermined rule based on the locating value, and encrypt the message blocks and the at least one redundancy value block placed therein to provide an encrypted message, and transmit the encrypted message over the network connection.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] In drawings which illustrate by way of example only a preferred embodiment of the invention,
[0016] FIG. 1 is a block diagram of a system for securely adding redundancy to an electronic message.
[0017] FIG. 2 a is a block diagram of a message created by the system of FIG. 1 prior to the secure addition of redundancy.
[0018] FIGS. 2 b , 2 c , and 2 d are block diagrams of messages created by the system of FIG. 1 after the secure addition of redundancy.
[0019] FIG. 2 e is a block diagram of the message of FIG. 2 d after the extraction of a redundancy block.
[0020] FIG. 3 is a flow diagram showing a method for securely adding redundancy to an electronic message.
[0021] FIG. 4 is a flow diagram showing a method for performing a redundancy check upon receipt of an electronic message.
DETAILED DESCRIPTION OF THE INVENTION
[0022] Referring to FIG. 1 , a communication device 10 is provided. The communication device 10 is provided with a processor 20 , memory 30 , an e-mail module 40 , and an input device 50 . The communication device 10 may be a personal computer, personal digital assistant, wireless mobile communication device or the like.
[0023] The communication device 10 is provided with an operating system and other elements known in the art used for the operation and control of the communication device, which are used in conjunction with the processor 20 and the memory 30 . The memory 30 may include random-access memory for temporary storage of messages composed by the user of the communication device 10 . The input device 50 may be a keyboard, touch-sensitive screen, or other suitable data entry device for the user of the communication device 10 for providing commands and entering data into the device 10 . The communication device 10 is connected to a wide-area network 100 via a connection that may comprise a wireless gateway or a fixed link.
[0024] The e-mail module 40 is preferably provided as application software that is executable on the operating system of the communication device 10 . E-mail module 40 receives instructions and data from the user via the input device 50 . The data may include the content of an e-mail message to be sent, as well as the e-mail address of the intended recipient. Instructions may include the command to “send” the e-mail to the intended recipient, or another command by which the user indicates to the module 40 that composition of the message content is complete.
[0025] In the preferred embodiment, as shown in FIG. 1 , e-mail module 40 includes program code executable on communications device defining a formatting/encoding layer 42 and program code defining an encryption/decryption layer 44 . When a user has defined an e-mail message and issues the send command, the program code in the formatting/encoding layer 42 executes to format and encode the e-mail message. In the preferred embodiment the encoding results in the defined e-mail message being placed in a commonly recognized format for electronic mail correspondence.
[0026] According to the preferred embodiment, shown in FIG. 2 a , the formatted and encoded message 200 comprises a number of blocks. Block 210 comprises header information, which may include data such as the recipient's address, a subject line, a date and timestamp, and an encryption or session key K assigned to the message by the e-mail module 40 , in accordance with techniques known in the art. Blocks 220 a . . . h contain the content of the message. It will be understood by those skilled in the art that the format of the e-mail message is not required to be defined by blocks or to include the information set out in the example of the preferred embodiment. However, to permit e-mail messages to be widely used, the general format set out is typically used.
[0027] After formatting and encoding have taken place, message 200 is then passed to executing program code in the encryption/decryption layer 44 . Preferably, the formatted and encoded message 200 is stored in the memory 30 of the communication device 10 , and the formatting/encoding layer 42 passes a pointer to the memory location of the formatted and encoded message 200 to the encryption/decryption layer 44 .
[0028] The encryption/decryption layer 44 accesses the formatted and encoded message 200 , and calculates a redundancy check value based on the content of the message blocks 220 a . . . h , such as a hash or CRC value, in accordance with techniques known in the art. The encryption/decryption layer 44 encodes the redundancy check value into one or more blocks, and inserts these blocks into blocks of the formatted and encoded message, according to the method described below. After the redundancy check value is inserted into the message 200 , the encryption/decryption layer 44 encrypts the message 200 , including the blocks having the value of the redundancy check (using session key K). The encrypted message is then made available to be transmitted to the network 100 by the e-mail module 40 for receipt by the recipient communication device.
[0029] Referring to FIG. 2 b , in a preferred embodiment, the encryption/decryption layer 44 carries out a calculation to specify the location or locations in the message where the redundancy value blocks will be inserted. In accordance with the preferred embodiment, the location of the redundancy values is not uniformly defined to be at the end of the message content blocks. Rather, the location is specified by variable values. In the example relating to FIG. 2 b , the location or locations are specified based on the content of the message 200 , itself. For example, the encryption/decryption layer 44 inspects the first block of the message 220 a to determine the number of 1s or 0s contained therein. If, in the example of FIG. 2 a , the block 220 a contains five 1s, the encryption/decryption layer 44 inserts a single block 230 containing the redundancy value between the fifth and sixth blocks 220 e and 220 f of the message 200 , as shown in FIG. 2 b.
[0030] More preferably, the redundancy value is split into a plurality of blocks to further obfuscate the location of the redundancy within the message 200 . If the redundancy value is to be split between two blocks 230 a and 230 b , the encryption/decryption layer 44 inspects a plurality of blocks of the message, for example the first and second blocks 220 a and 220 b . If, in the example of FIG. 2 a , the second block 220 b contains three 1s, the encryption/decryption layer 44 inserts the first redundancy value block 230 a between the fifth and sixth blocks 220 e and 220 f of the message 200 , and the second redundancy block 230 b between the third and fourth blocks 220 c and 220 d , as shown in FIG. 2 c.
[0031] In a most preferred embodiment, the location of the blocks containing the redundancy value is determined by the value of the session key K. The encryption/decryption layer 44 counts the number of 0s appearing in the binary representation of the value of session key K. If this number is even, then the first redundancy value block 230 a is placed between first and second blocks 220 a and 220 b of the message 200 . If this number is odd, then the first redundancy value 230 a is placed between the second and third blocks 220 b and 220 c of the message 200 .
[0032] Further, if the key value is divisible by four, then the encryption/decryption layer 44 places the second redundancy value block 230 b between the fifth and sixth blocks 220 e and 220 f of the message 200 ; otherwise, the second redundancy value block 230 b is placed between the sixth and seventh blocks 220 f and 220 g of the message 200 . The resultant arrangement of blocks in the message 200 in this embodiment is shown in FIG. 2 d in an example where the number of 0s in K is 6, and K is an even number that is not a multiple of 4. This method of determining the locations of the redundancy value blocks 230 a, b is most preferred as the total message length of the message 200 may be short; if the locations of the redundancy blocks were determined principally based on a high number of 1s or 0s appearing in the session key or a message block 220 , for example, the encryption/decryption layer 44 might attempt to place a redundancy value block 230 between two message blocks 220 that did not actually exist, resulting in an error condition.
[0033] When an encrypted message with redundancy thus added is received from a sender over the network 100 by the e-mail module 40 of the recipient's communication device 10 , the encrypted message is passed to the encryption/decryption layer 44 , which first decrypts the message 200 . The encryption/decryption layer 44 operates to extract the redundancy blocks 230 a,b from the message 200 to determine the redundancy check value.
[0034] As a person skilled in the art will understand, the extraction of redundancy blocks by recipient's communication device is defined in a way that matches the way that sender's communication device 10 inserts such blocks. The recipient's communication device is therefore provided with sufficient information to determine the locations of the redundancy value blocks 230 a,b . Thus, for example, if the sender's communication device 10 is configured to evaluate the number of 1s in the first block 220 a of the message in order to determine the location of a redundancy block 230 a , then the receiver's communication device 10 is likewise configured to evaluate the number of 1s in the first block 220 a of the received message. The necessary information may be transmitted from the sender to the recipient separately from the encrypted message; however, if the information used to determine the locations of the redundancy value blocks 230 a,b is the session key K, a portion of the information necessary to locate the redundancy value blocks 230 a,b is thus transmitted along with the encrypted message.
[0035] For example, where the receiver's communication device 10 receives the encrypted version of the message 200 depicted in FIG. 2 d and is configured to use the session key K to determine the location of the redundancy value blocks 230 a,b , the encryption/decryption layer 44 in the receiving device 10 first decrypts the message to arrive at the message 200 shown in FIG. 2 d . The encryption/decryption layer 44 next examines the session key K and determines that there were six 0s contained in the session key K. As six is an even number, the first redundancy value block 230 a is extracted from the message 200 from between the first and second blocks 220 a , 220 b , as shown in FIG. 2 e . The message 200 is then temporarily stored in the memory 30 of the receiver's communication device 10 . Next, the encryption/decryption layer 44 determines that the number of 0s in the session key, six, is not divisible by four, and therefore extracts the second redundancy block 230 b from between the sixth and seventh blocks 220 f, g . The contents of the redundancy blocks 230 a,b are then assembled to generate an extracted redundancy value R E .
[0036] The encryption/decryption layer 44 in the receiving device 10 then computes its own redundancy value R C based on the content of the message blocks 220 a . . . h , and compares this R C to R E . If the values match, then the receiving device 10 determines the message to be unaltered. If the values do not match, then the message is determined to have been altered, and preferably a warning is provided to the recipient.
[0037] As a person skilled in the art will appreciate, the means of determining the location of the n redundancy value blocks 230 a . . . h is not restricted to an evaluation of the content of the first n blocks of the message 200 or the session key K. Other suitable and variable characteristics of message content, for example message length, may be used to establish the location of the redundancy value blocks 230 a . . . h . Alternatively, another parameter that is not dependent on the message content may be used to determine the location of the redundancy block or blocks 230 a . . . h . Provided that the communication devices 10 of each of the sender and the intended recipient of the message are provided with the same means for determining the locations of the redundancy blocks 230 a . . . h of the message 200 , such other means may be used, although most preferably the locations generated by these means can potentially vary from message to message.
[0038] Thus, for example, a look-up table or database, which may be populated with values determined using a pseudo-random number generator, can reside on a mail server on the network 100 , accessible to both the sender's and recipient's communication devices. When a message is passed to the encryption/decryption layer 44 of the sender's communication device 10 , the sender's device 10 then queries the database for a value to be used in determining the locations of the redundancy blocks 230 a . . . h . This value may be transmitted to the recipient's communication device 10 together with the message, or alternatively pointer information may be transmitted to the recipient's communication device 10 . This pointer information may comprise the timestamp of the message, which is correlated with the value stored in the database once the message is transmitted. When the recipient's communication device 10 receives the message 200 , the recipient's device 10 can then retrieve the pseudo-random number from the database.
[0039] Referring to FIG. 3 , a method of securely adding message redundancy to an electronic message is shown according to a preferred embodiment. At step 300 , a message composed by a user is received by the e-mail module 40 of a communication device 10 . The message is then formatted and encoded by the formatting/encoding layer 42 at step 310 , then passed to the encryption/decryption layer 44 of the module 40 at step 320 .
[0040] At step 330 , the encryption/decryption layer 44 calculates a redundancy value and encodes it into one or more blocks. At step 340 , the encryption/decryption layer 44 determines one or more locations for placing the blocks containing the redundancy value. At step 350 , the redundancy value blocks are inserted within the message, then the message is encrypted at step 360 . Finally, at step 370 , the message is dispatched to the recipient.
[0041] The method of decrypting a received message and determining whether the message has been altered before reception by the intended recipient is shown in FIG. 4 . At step 400 , a message is received by a communication device 10 over a network 100 . The message is passed to the encryption/decryption layer 44 of the e-mail module 40 within the device 10 at step 410 . The encryption/decryption layer 44 decrypts the message at step 420 , then determines the locations of the redundancy value blocks at step 430 . At step 440 , the redundancy value blocks are extracted from the message and assembled to produce the extracted redundancy value R E . A calculated redundancy value, R C , is then determined from the content of the message at step 450 , and the values R C and R E are compared at step 460 . If the values match, then the message is determined to be unaltered, 470 ; otherwise, it is determined to have been altered, and preferably a warning is issued to the recipient at 480 .
[0042] Various embodiments of the present invention having been thus described in detail by way of example, it will be apparent to those skilled in the art that variations and modifications may be made without departing from the invention. The invention includes all such variations and modifications as fall within the scope of the appended claims. | A system for adding a redundancy check to an electronic message to discourage tampering and facilitate identification of altered messages provides a communication device for composing message content, a messaging module with a formatting and encoding layer for encoding the message content with header information in a series of message blocks, and an encryption layer for calculating a redundancy check value and inserting the value in one or more locations within the series of message blocks according a rule defined by a characteristic of the message content or the header information, and encrypting the message for delivery to a recipient. Upon receipt, the recipient communication device decrypts the message, extracts the redundancy check value from the message, and compares a calculated redundancy check value with the extracted redundancy check value to determine if the message had been altered before receipt. | 7 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to an oil-dispersible composite of metallic nanoparticles and a method for synthesizing the same. Particularly, the oil-dispersible composite includes an oily polymeric polymer capable of chelating the metal. The oil-dispersible composite at high concentrations can be made into a film suitable for applications in electronics, sensors, antibacterial materials, nano-composites and polymers.
[0003] 2. Related Prior Arts
[0004] Water is generally the solvent for producing silver nanoparticles (AgNPs). However, silver nanoparticles always gather with each other due to van der Waals' forces and it's hard for them to be dispersed in oily solvents or made in the form of powders. Therefore, it's very important to make silver nanoparticles more compatible with oily solvents in addition to controlling the particle size and stability.
[0005] To control particle sizes of the silver nanoparticles in chemical reduction processes, their thermal stability and compatible solvent phases should be considered. Therefore, organic surfactants or stabilizers are usually added to stabilize the silver nanoparticles in accordance with their electrostatic repulse or steric hindrance.
[0006] The known stabilizers include sodium polyacrylate, polyacrylamide (see J. Phys. Chem. B 1998, 102, 10663-10666), thioalkylated poly(ethylene glycol) (see Chem. Mater. 2005, 17, 4630-4635), 3-aminopropyltrimethoxysilane (APS) (see Langmuir 1999, 15, 948-951) and sodium citrate (see J. Phys. Chem. B 1999, 103, 9533-9539). The known surfactants include cationic surfactants such as cetyltrimethylammonium bromide-CTAB, anionic surfactants such as sodium dodecyl sulfate-SDS and nonionic surfactants such as ethoxylated (see Langmuir 1996, 12, 3585-3589) and poly(oxyethylene) isooctylphenyl ether-TX-100 (see Langmuir 1997, 13, 1481-1485).
[0007] To form silver paste, the solid content is required to be over 10 wt %. However, the above methods can proceed only in water phase and self-aggregation of the silver particles occurs at high solid contents. To prevent the reduced particles from aggregating, the concentrations of the silver ions must be lowered to ppm ranges during the reduction process. Moreover, the above methods require high cost because of complex processes and lengthy operations.
[0008] Therefore, the present invention provides an efficient method compatible with various solvent phases and capable of producing oil-dispersible silver nanoparticles.
SUMMARY OF THE INVENTION
[0009] The object of the present invention is to provide an oil-dispersible composite of metallic nanoparticles, so that the metal (particularly silver) nanoparticles not only have a proper size and good stability but also are dispersible in oily organic solvents at high concentrations.
[0010] Another object of the present invention is to provide a method for producing an oil-dispersible composite of metallic nanoparticles, which can be operated in moderate conditions and with metal ions of high concentrations.
[0011] The oil-dispersible composite of metallic nanoparticles of the present invention primarily includes metallic nanoparticles and an oily polymeric polymer. The oily polymeric polymer serves as carriers of the metallic nanoparticles to uniformly disperse the nanoparticles. The oil-dispersible composite have a size of about 5 to 100 nm, and preferably 5 to 33 nm. The metal can be Au, Ag, Cu or Fe. The oily polymeric polymer has a functional group capable of chelating the metal and has a molecular weight ranging from 2,000 to 200,000 g/mol.
[0012] The weight ratio of the above oily polymeric polymer to the metallic nanoparticles preferably ranges from 1:1 to 100:1. The oily polymeric polymer is preferably polyurethane (PU), which more preferably includes a poly(oxyalkylene) segment (—(CH 2 CH 2 O) x — or polyethylene glycol (PEG)) and a hydroxyl group (—OH) so as to chelate the metal ions and serve as a dispersant. For example, polyurethane (PU) has a structural formula as follows:
[0000]
[0000] The metal is preferably Ag and a preferred composite is AgNP/PU.
[0013] In the present invention, the oil-dispersible metallic nanoparticles can be in the form of a solution or a film. Preferably, the metallic nanoparticles are present in an amount of 20 to 50 wt % in the film.
[0014] In the present invention, the method for producing the oil-dispersible composite of metallic nanoparticles primarily includes steps of: (a) reacting an oily polymeric polymer with metal ions in a solvent at 15 to 35° C. for 0.5 to 3 hours; wherein the metal is Au, Ag, Cu or Fe; and the oily polymeric polymer has a functional group capable of chelating the metal and a molecular weight ranging from 2,000 to 200,000 g/mol; (b) adding an organic reducing agent into the above solution to reduce the metal ions into metal atoms at 10 to 80° C. and form an oil-dispersible composite having a particle size 5 to 100 nm (even 5 to 33 nm); wherein the reducing agent is ethanolamine, poly(oxyalkylene)-amine or a polymer of ethanolamine, poly(oxyalkylene)-amine and epoxy.
[0015] In the above step (a), the weight ratio of the oily polymeric polymer to the metal preferably ranges from 1:1 to 100:1; the oily polymeric polymer is preferably polyurethane (PU); and the metal is preferably silver.
[0016] In the above step (b), the organic reducing agent can be ethanolamine having a general formula (HOCH 2 CH 2 ) 3-z N(R) z , wherein z=0, 1 or 2, R═H, alkyl or alkenyl having 1 to 18 carbon atoms. The organic reducing agent is preferably poly(oxyalkylene)-amine having a molecular weight of 400 to 6,000 g/mol, for example, poly(oxyethylene) amine, poly(oxypropylene) amine or poly(oxyethylene-oxypropylene) amine. Poly(oxyalkylene)-amine can be poly(oxyalkylene)-monoamine, poly(oxyalkylene)-diamine or poly(oxyalkylene)-triamine. In addition, the organic reducing agent can be a polymer of ethanolamine, poly(oxyalkylene)-amine and epoxy, wherein poly(oxyalkylene)-amine preferably has two amino groups to respectively bonding with ethanolamine and epoxy. Epoxy can be diglycidyl ether of bisphenol-A (DGEBA), 3,4-epoxycyclohexyl-methyl-3,4-epoxycyclohexane carboxylate, poly (ethylene glycol) diglycidyl ether or poly (propylene glycol) diglycidyl ether.
[0017] In the above step (b), the molar ratio of the metal to the organic reducing agent preferably ranges from 1:1 to 100:1, and more preferably from 1:1 to 10:1. The temperature of reduction reaction is about 10 to 80° C., and the reaction time is about 1 to 30 hours. The preferred operating conditions are: (i) ethanolamine as the reducing agent, reacting at 20 to 65° C. for 2 to 5 hours; (ii) poly(oxyalkylene)-amine as the reducing agent, reacting at 15 to 35° C. for 20 to 30 hours; or (iii) a polymer of ethanolamine, poly(oxyalkylene)-amine and epoxy as the reducing agent, reacting at 20 to 80° C. for 3 to 5 hours.
[0018] The method of the present invention can further include a step: (c) drying the oil-dispersible composite of metallic nanoparticles of step (b) so that the metallic nanoparticles are present in a concentration of 20 to 50 wt %.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] FIG. 1 shows the synthesis reaction and the structure of polyurethane (PU) suitable for the present invention.
[0020] FIG. 2 shows examples of ethanolamine suitable for the present invention.
[0021] FIG. 3A shows examples of poly(oxyalkylene)-amine suitable for the present invention.
[0022] FIG. 3B shows examples of poly(oxyalkylene)-amine suitable for the present invention.
[0023] FIG. 3C shows examples of poly(oxyalkylene)-amine suitable for the present invention.
[0024] FIG. 4 shows examples of epoxy suitable for the present invention.
[0025] FIG. 5 shows UV absorbance of AgNP/PU obtained at different reaction times and using DEA as the reducing agent.
[0026] FIG. 6 shows UV absorbance of AgNP/PU obtained using different poly(oxyalkylene)-amines as the reducing agents.
[0027] FIG. 7 shows the synthesis reaction of BE188/ED2003/MEA (EEM).
[0028] FIG. 8 shows the particle sizes of silver in AgNP/PU observed with TEM (transmission electron microscopy).
[0029] FIG. 9 shows the silver distributed in AgNP/PU films formed at different temperatures and observed with SEM.
ATTACHMENTS
[0030] ATTACHMENT 1 shows the operating conditions of Examples and Comparative Examples.
ATTACHMENT 2 shows particle sizes of AgNP/PU of Examples 3.1 to 3.5.
ATTACHMENT 3 shows solubilities of AgNP/PU in different solvents.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0031] In the present invention, the materials used in Examples and Comparative Examples include
1. Polyurethane (PU): purchased from Kuo-Ching Chem. Co.; product name KC58238AU; FIG. 1 shows the synthesis reaction from polyethylene glycol (PEG), 1,4-butandiol and 4,4-methylenediphenyl isocyanate. 2. Silver nitrate: AgNO 3 (99.8 wt %), as the source of silver ions, purchased from Aldrich Co.; other silver salts such as AgI, AgBr, AgCl and silver pentafluoropropionate can also be used. 3. Reducing agents: (1) Ethanolamine: the general formula (HOCH 2 CH 2 ) 3-x N(R) x , x=0, 1 or 2; R═H or alkyl or alkenyl having 1 to 18 carbon atoms; for example, methyl, ethyl or cyclohexyl; FIG. 2 shows several examples. The preferred examples include diethanolamine (DEA), monoethanolamine (MEA), diglycolamine (DGA) and (±)-1-Amino-2-propanol (MPA). (2) Poly(oxyalkylene)-amine: including monoamine, diamine and tramine, having POE (poly(oxyethylene)) or POE (poly(oxypropylene)) segments, serving as monomers for reducing silver ions. FIG. 3 shows the examples. Those used in Examples are purchased from Huntsman, product names ED-2003, D-2000, M-2070, T-403 and T-5000. (3) Epoxy: capable of reacting with ethanolamine and poly(oxyalkylene)-amine to generate an oily polymeric polymer, FIG. 4 shows the diglycidyl ether derivatives of epoxy. In Examples diglycidyl ether of bisphenol A (BE188) is used.
[0038] The detailed steps are described as follows and the operating conditions are shown in ATTACHMENT 1:
Example 1.1
Step (a) Chelating Silver Ions by PU
[0039] To a three-necked bottle containing dimethyl fumarate (DMF, 10 g), PU (30 wt %, 10 g) was added and diluted to 15 wt % with mechanical mixing. Then AgNO 3 (1.18 g, including 0.75 g of Ag) was added such that the weight ratio of PU:Ag was 4:1. After being mixed at room temperature for 1 hour, the silver nitrate was disolved completely and the solution turned from semi-opaque to light yellow. With UV spectrum analysis, absorbance of silver was observed which indicated silver nanoparticles were generated.
Step (b) Reducing Silver Ions into Silver Nanoparticles
[0040] Then, DEA (0.109 g) was added and the molar ratio of AgNO 3 :DEA was 1:0.15. After reacting at 55° C. for 3.5 hours, the solution turned from light yellow into deep black. FIG. 5 showed UV absorbance of AgNP/PU with reaction time. The data indicated that the absorbance at 436 nm hardly increased after 3.5 hours and the peak shifted to 439 nm at the 4th hour and the absorbance gradually decreased. The reason was that self-aggregation of the silver particles occurred.
Examples 1.2 to 1.4
[0041] Steps of Example 1.1 were repeated, except that DEA of step (b) was replaced with MEA, DGA and MPA, and the molar ratio of AgNO 3 :ethanolamine was kept at 1:0.15. As a result, high-concentration and thermally-stable silver nanoparticles were generated.
Examples 2.1 to 2.3
[0042] Steps of Examples 1.2 to 1.4 were repeated, except that the reduction temperature of step (b) was changed to room temperature, and the weight ratio of PU:Ag was changed to 1.5:1. As a result, high-concentration silver nanoparticles were generated.
Examples 3.1 to 3.5
[0043] Steps of Example 1.1 were repeated, except that the reducing agent of step (b) was replaced with poly(oxyalkylene)-amine (Jeffamine® ED-2003, D-2000, M-2070, T-403 and T-5000, respectively), and the weight ratio of PU:AgNO 3 :poly(oxyalkylene)-amine was 4:1:1. After reacting at room temperature for 24 hours, black silver nanoparticles were obtained. The solution was then diluted to 500 ppm and became transparent brown. FIG. 6 showed the UV absorbance of AgNP/PU. ATTACHMENT 2 showed particle sizes of AgNP/PU of Examples 3.1 to 3.5. The results indicated that the commercialized hydrophobic or hydrophilic poly(oxyalkylene)-amine could be used to reduce silver ions into silver nanoparticles.
Examples 4.1 to 4.5
Synthesizing EEM
A Polymer of Ethanolamine, Poly(Oxyalkylene)-Amine and Epoxy
[0044] ED2003 was dewatered in vacuum at 120° C. for 6 hours. To a 500 ml three-necked bottle, BE188 (7 g, 0.02 mol), ED2003 (40 g, 0.02 mol) and MEA (1.22 g, 0.02 mol) were added and the molar ratio of BE188/ED2003/MEA was 1/1/1. The solution was mechanically mixed and the reaction proceeded in nitrogen at 120° C. for at least 5 hours. FIG. 7 showed the synthesis reaction. The reaction was monitored with IR spectrum and the solution was sampled every certain period till the feature peak of epoxy functional group did not appear. After complete reaction, light yellow stick product, the oily polymeric polymer BE188/ED2003/MEA (abbreviated as EEM), was achieved for the following reduction reaction.
Step (a) Chelating Silver Ions by PU
[0045] DMF (10 g) was added into PU (30 wt %, 10 g) and diluted to 15 wt % and then placed in a three-necked bottle for mechanically mixing. Then AgNO 3 (1.18 g) was added and the weight ratio of PU:Ag was 4:1. The solution was mixed at room temperature for 1 hour and the silver nitrate was dissolved completely. The solution became light yellow from semiopaque. Four more solutions the same as the above were prepared.
[0000] Step (b) Reducing Silver Ions into Silver Nanoparticles
[0046] To the above five solutions, EEM of different amounts (0.3 g, 0.2 g, 0.06 g, 0.03 g, 0.006 g) were respectively added and the solutions became red brown at room temperature. After reacting for 1 hour, the solutions were heated to 60° C. After reacting for 3 hours, the solutions became deep black from red brown. The products were diluted to 500 ppm with DMF and red brown to golden solutions were achieved.
Comparative Example 1
[0047] Procedures of Example 1.1 were repeated, except that no organic reducing agent was added. Finally, though stable silver ions were obtained, only a small part thereof could be reduced into silver nanoparticles. That is, the reducing agents of the present invention were necessary.
Comparative Example 2
[0048] Procedures of Example 1.1 were repeated, except that the reducing agent was replaced with a water-soluble salt, NaBH 4 . The solution looked like a gel. After several hours, the gel became black and was not dispersible. That is, the reducing agents of the present invention were necessary.
[0049] The AgNP/PU achieved in Example 1.1 could be further treated as follows:
1. The AgNP/PU was diluted with DMF to 35 ppm to form a golden solution of AgNP/PU. The particle sizes of AgNP were observed with TEM, ranging from 5 to 43 nm, as shown in FIG. 8 . Other solvents such as dimethyl fumarate (DMF), N-methyl-2-pyrrolidone (NMP) or dimethyl sulfoxide (DMSO) or a co-solvent including one of the three solvents (NMP, DMF, DMSO) could be used to dilute the AgNP/PU. ATTACHMENT 3 showed solubilities of the AgNP/PU in solvents. 2. The above golden solution of AgNP/PU was dried at 60° C. for 1 hour and a thin film of AgNP/PU was achieved. FIG. 9 showed the silver distributed in AgNP/PU films formed at different temperatures and observed with SEM. The particle sizes were about 5 to 25 nm. Similarly, AgNP/PU of Example 4.3 to 4.5 could be formed as thin films. 3. For the film of AgNP/PU dried at 150° C., the particle sizes were about 15 to 65 nm, as shown in FIG. 9 . The reason might be migration of silver nanoparticles to the surface during heating. 4. The above films of AgNP/PU could be dissolved in DMF, NMP or co-solvents of ATTACHMENT 3 again. The silver nanoparticles can still be present in high concentrations and have good thermal stability.
[0054] From the above Examples and Comparative Examples, the following conclusions could be drawn:
1. The oily polymeric polymer (PU) used to produce AgNP/PU dispersion facilitates stability, film-forming and controlling particle size of the silver nanoparticles. 2. By controlling the weight ratio of the oily polymeric polymer to silver particles, the particle sizes of AgNP/PU composite are uniformly distributed at a nano scale, usually smaller than 100 nm, and even less than 10 nm. 3. Compared to traditional silver dispersions having an upper limit at about 5 wt % and disadvantages of precipitation and self-aggregation, the present invention provides a AgNP/PU dispersion with high concentrations and uniformity. 4. The AgNP/PU dispersion of the present invention can form thin films after being dried; and the films can be stably dispersed in several solvents again. 5. The AgNP/PU of the present invention is hydrophobic so that the dispersing media can be organic solvent, for example, dimethyl fumarate (DMF), N-methyl-2-pyrrolidone (NMP) or dimethyl sulfoxide (DMSO), or co-solvents of the above solvents and other organic solvents such as isopropyl alcohol (IPA), acetone, methyl ethyl ketone (MEK) and toluene. 6. The AgNP/PU of the present invention has good electrical conductivity or antibacterial property and thus is suitable for applications with organic polymers to form nano composite; for example, polyimide (PI), epoxy, nylon, polypropylene (PP), acrylonitrile butadiene styrene (ABS), polystyrene (PS), etc. 7. By the method of the present invention, the composite of silver nanoparticles can be produced without any surfactant and is dispersible in oily solvents and compatible with many kinds of polymers. 8. Compared to the traditional processes, the method of the present invention is conducted under more moderate conditions and therefore needs a lower cost.
[0000]
ATTACHMETN 1
Example/
Comparative
AgNO 3
PU/Ag
Reducing
Reducing
Reduction
Reduction
Example
(g)
(w/w)
agent
agent (g)
Ag/Reducing agent
temp. ( )
time (h)
Example 1.1
1.18
4/1
DEA
1/0.15
(mol/mol)
55
3.5
Example 1.2
1.18
4/1
MEA
1/0.15
(mol/mol)
55
3.5
Example 1.3
1.18
4/1
DGA
1/0.15
(mol/mol)
55
3.5
Example 1.4
1.18
4/1
MPA
1/0.15
(mol/mol)
55
3.5
Example 2.1
1.18
1.5/1
MEA
1/0.15
(mol/mol)
RT
3.5
Example 2.2
1.18
1.5/1
DGA
1/0.15
(mol/mol)
RT
3.5
Example 2.3
1.18
1.5/1
MPA
1/0.15
(mol/mol)
RT
3.5
Example 3.1
1.18
4/1
ED-2003
1/1
(w/w)
RT
24
Example 3.2
1.18
4/1
D-2000
1/1
(w/w)
RT
24
Example 3.3
1.18
4/1
M-2070
1/1
(w/w)
RT
24
Example 3.4
1.18
4/1
T-403
1/1
(w/w)
RT
24
Example 3.5
1.18
4/1
T-5000
1/1
(w/w)
RT
24
Example 4.1
1.18
4/1
EEM
0.3
1/0.4
(w/w)
RT (Room temperature)
Example 4.2
1.18
4/1
EEM
0.2
1/0.26
(w/w)
for 1 h, and 60 for 3 h
Example 4.3
1.18
4/1
EEM
0.06
1/0.08
(w/w)
Example 4.4
1.18
4/1
EEM
0.03
1/0.04
(w/w)
Example 4.5
1.18
4/1
EEM
0.006
1/0.008
(w/w)
Comparative
—
—
—
55
3.5
Example 1
Comparative
NaBH 4
1/0.15
55
3.5
Example 2
EEM/BE188/ED2001/MEA
[0000]
ATTACHMETN 2
Average diameter
Example
Reducing agent
(nm)
3.1
ED-2003
4.4
3.2
D-2000
3.7
3.3
M-2070
4.7
3.4
T-403
9.5
3.5
T-5000
29.2
[0000]
ATTACHMETN 3
A
B
water
ethanol
acetone
Toluene
IPA
PGMEA
NMP
DMF
DMSO
x
x
x
x
x
x
∘
∘
∘
NMP
∘ b
∘ b
∘ a
∘ a
∘ a
∘ a
∘ a
∘ a
∘ a
DMF
∘ b
∘ b
∘ a
∘ a
∘ a
∘ a
∘ a
∘ a
∘ a
a A/B = 1/1 (w/w)
b A/B = 10/1 (w/w)
IPA: isopropyl alcohol
PGMEA: Propylene glycol monomethylether acetate
NMP: N-methyl-2-pyrrolidinone
DMF: Dimethylformamide
DMSO: Dimethyl sulfoxide
∘: good solubility
x: not good solubility | The present invention provides an oil-dispersible composite of metallic nanoparticles and a method for synthesizing the same. The composite primarily includes metallic nanoparticles and an oily polymeric polymer such as polyurethane (PU). The oily polymeric polymer serves as a carrier of the metallic nanoparticles by chelating therewith so that the metallic nanoparticles are dispersed uniformly. In the method of the present invention, the metallic ions are first chelated by the oily polymeric polymer and then reduced into nanoparticles. The composite of the present invention is about 5 to 100 nm in particle size. | 2 |
CROSS-REFERENCE TO RELATED APPLICATION
[0001] The subject matter of this application is related to the subject matter of copending U.S. patent application Ser. No. 10/679,836 filed Oct. 6, 2003, entitled “Computerized System and Method for Determining Work in a Healthcare Environment”; and to the subject matter of U.S. patent application Ser. No. 10/917,337 filed Aug. 13, 2004, entitled “System And Method For Automatically Generating Evidence-Based Assignment Of Care Providers To Patients”, each of which applications is assigned or under obligation of assignment to the same entity as this application, and each of which applications is incorporated by reference herein.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] Not applicable.
FIELD OF THE INVENTION
[0003] The invention relates to the field of clinical information technology, and more particularly to a system and method for a management interface which presents a charge nurse or other staffing manager with an intuitive, visual interface for generating patient-to-care provider assignments, including capacity computation, skill set matching, ratio management and other parameters as part of that interface.
BACKGROUND OF THE INVENTION
[0004] The healthcare environment continues to demand increased attention to and emphasis on clinical workforce management, including to deploy nurses, technicians, rehabilitation and other staff with better efficiency and clinical efficacy. Hospitals and other clinical sites furthermore may find themselves operating under federal, state or other compliance requirements which demand that the ratio of care providers to assigned patients adhere to specified ratios or that the staffing level is appropriate for the level of acuity of the relevant patient population. Those regulatory considerations combined with operational needs such as the need to continuously mix and adjust provider assignments under day to day schedule changes such as vacation time, lunch and other breaks, sick days, and other absences or developments make the task of promulgating shift-by-shift patient assignments a challenging one, for charge nurses and other clinical managers tasked with staffing duties.
[0005] Those staff managers moreover are frequently confronted with the need to generate provider/patient assignments with no formal or computerized tools to assist in that workforce management. Charge nurses or other unit or other managers thus must frequently rely on manual notes, memory and intuition to assemble a staff schedule and make appropriate provider-to-patient assignments on an ad hoc or short-term basis. Staff managers may moreover often have little time to generate such a floor schedule for the next shift, week or other period even on a manual basis. Other problems in clinical workforce management exist.
SUMMARY OF THE INVENTION
[0006] The invention overcoming these and other problems in the art relates in one regard to a system and method for a clinical workforce management interface, in which a staff manager may be presented with a suite of provider assignment options and alternatives, to automatically organize and drive assignment ratios and other assignment parameters and options with compliance, capacity, best practice and other criteria taken into account. According to embodiments of the invention in one regard, a visual or graphical interface or other presentation layer may present a charge nurse or other staff manager with a patient list including graphical or iconic representations of the continuity and types of assigned provider care for each patient, for instance in a slider bar showing continuity of provider assignments or any gaps therein, for example over a shift, 24 hours, week or other periods. In embodiments, the assignment bar, provider names, icons or other visual elements or objects may be manipulated, for instance dragged and dropped, to effect assignments, changes to assignments or other actions. The interface may likewise indicate the acuity or amount of work which a given patient's care will demand of a provider, and generate aggregate totals of the amount of capacity in a clinical unit available to serve the patient population. Mandated patient-to-provider ratios may automatically be monitored, and alerts may be presented when those or other compliance, operational or other criteria are violated. Because in one regard an entire range of workforce management functions may be integrated in one interface, and that interface or tool may automatically present and analyze core capacity and other variables and options, as well as store resulting assignments and schedules to distribute to staff and form a basis for or input to further schedules, the overall task of timely workforce assignments may be achieved more efficiently, compliance may be better ensured while capacity may be more effectively managed against fluctuating clinical demands.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] FIG. 1 illustrates a clinical workforce environment in which a system and method for a workforce management interface may operate, according to embodiments of the invention.
[0008] FIG. 2 illustrates a workforce management interface, according to embodiments of the invention.
[0009] FIG. 3 illustrates a workforce management interface including an alert, according to embodiments of the invention.
[0010] FIG. 4 illustrates a flowchart of overall workforce management and interface processing, according to embodiments of the invention.
DETAILED DESCRIPTION OF EMBODIMENTS
[0011] FIG. 1 illustrates an environment in which a system and method for a clinical workforce management interface may operate, according to embodiments of the invention. As illustrated in that figure, a charge nurse or other personnel or staff manager may operate a client 102 having a graphical user interface 104 to initiate, access or execute a workforce management interface 106 . The staff manager may access the workforce management interface 106 before, during or after a work shift for a unit 110 such as an emergency room, acute care unit, post-operative unit or other section, division, department, floor or other organizational unit of a hospital or other clinical care facility. The staff manager may operate the workforce management interface 106 to schedule shifts, generate care provider-to-patient assignments, review capacity loads and perform other personnel or staffing duties with respect to a care provider staff 138 which may be or include, for example, nurses, therapists, technicians, physicians, interns, or other clinical or other personnel whose responsibilities or activities are directed to or associated with patients in unit 110 , or otherwise.
[0012] According to embodiments of the invention as for example illustrated in FIG. 2 , the workforce management interface 106 may include a range of views including graphical and numerical or textual indicators, activatable icons and other objects and resources to organize and visually present provider assignment information, in an integrated presentation layer or interface. According to embodiments as shown, those resources may include a patient population profile 112 which may be or include, for instance, a patient list 114 or other census or other enumeration of patients within unit 110 , or other grouping. The patient population profile 112 may include, for further example, a patient needs rating 116 indicating the rated amount of workload or work effort represented by a patient's care, for instance expressed in normalized units of person-hours, or other quantities or units. The patient population profile 112 may further include a set of skill criteria 118 , for instance indicating that the care of a particular patient requires specialized training, certification or skills, for example the training or competence to operate a high-frequency ventilator, or other skills.
[0013] According to embodiments of the invention in a further regard, and as likewise illustrated in FIG. 2 , the patient population profile 112 may likewise include an assignment bar 120 , which may in one regard depict or represent the presence, absence or type of care provider assignment or coverage for a given patient in patient list 114 , over a scheduled period of time. For instance, the assignment bar 120 may indicate that for an eight-hour shift from 11 p.m. to 7 a.m. or other period, the patient is covered by assignment of a primary care nurse, or other personnel. Conversely, if a patient does not have a designated care provider for that or other period, the assignment bar 120 may display a gap 122 , such as a white or other visually distinct color or segment, to indicate that a patient has not received an assignment of a care provider for the represented period. According to embodiments of the invention in a further regard, the assignment bar 120 may be activatable, for example by highlighting or clicking, to display an expanded assignment view 136 which presents details on a particular patient's provider assignment or assignments and related information, including for instance the category of provider (e.g. professional), time period ranges for that provider, and the name or other identifier for that provider. Other data may be presented in expanded assignment view 136 .
[0014] According to embodiments of the invention as illustrated in FIG. 2 in another regard, the workforce management interface 106 may likewise include views and resources directed to the pool of available care providers, including a provider population profile 124 which may contain a provider list 126 which may identify available care providers by name, or other designation. Provider population profile 124 may further contain a set of provider capacity ratings 128 which may indicate a given nurse's, therapist's, technician's or other person's capacity to undertake patient care, for instance expressed in person-hours of care, or other units. According to further embodiments of the invention, the provider capacity ratings 128 may include or incorporate a scaling or adjustment factor to take a given provider's experience level, specialized training, patient continuity and other factors into account, in rating the amount of normalized patient care that provider may contribute. According to embodiments of the invention in one regard, the provider capacity ratings 128 or other projected or estimated work capacity or production ratings may be generated by or accessed from a capacity platform or engine such as that described in the aforementioned U.S. patent application Ser. No. 10/679,836, or other platforms, systems or resources. Other computations or expressions of capacity in provider capacity ratings 128 are possible.
[0015] Provider population profile 124 as illustrated in FIG. 2 may further include a provider schedule 130 for care providers in provider list 126 , for instance indicating a provider's availability or expected presence for a given shift for certain hours of the day, or for other times or periods. According to embodiments of the invention in one regard, the workforce management interface 106 may permit a charge nurse or other staff manager to manipulate data, icons and other objects to assign, update, reassign, review and otherwise process a set of provider-to-patient (or patient-to-provider) assignments, in one regard in a visually comprehensible fashion. For example, a staff manager may determine that a patient inpatient list 114 lacks an assigned provider for a shift from 7 a.m. to 3 p.m. for a given day. The manager or other operator may then highlight, grab, click or otherwise activate a provider name in provider list 126 , and drag and drop that identifier onto assignment bar 120 for that patient, or otherwise associate the provider with the patient. In another embodiments, the user may select one or more patients and one or more providers, and initiate an automated assignment process such as the system and method described in the aforementioned U.S. patent application Ser. No. 10/917,337, or others. According to embodiments of the invention in one regard, the assignment bar 120 may automatically change appearance, for instance to be grayed in, to indicate care coverage from 7 a.m. to 3 p.m. Other visual, graphical or other indications or encodings are possible. According to embodiments of the invention in one regard, that assignment may be automatically generated, graphically presented and data such as provider capacity ratings 128 may be automatically updated, upon the registration of a new assignment in that drag and drop or other fashion. Other icons, objects and actions are possible.
[0016] According to embodiments of the invention illustrated in FIG. 2 in another regard, the workforce management interface 106 may likewise present a staff capacity breakdown 132 to present to the staff manager the total allocation of staff capacity during a given shift or other period in summary fashion, for instance to list providers in a table with their assigned patients and workload allocations. Other views, tabulations or reports are possible.
[0017] According to embodiments of the invention in a further regard, the workforce management interface 106 and associated logic may further monitor or condition patient assignments based on regulatory compliance, clinical best practices or other clinical or operational criteria. Thus for example, and as for example illustrated in FIG. 3 , the workforce management interface 106 may monitor for mandatory or other state, federal, industry or other compliance criteria regarding or limiting the acceptable ratio of care providers to patients or requiring staffing based on quantitative levels of acuity. When an attempt is made, for instance by selecting, dragging and dropping a care provider by name to an assignment bar 120 for a patient which would result in that provider's reaching a level of, for example, five (or other) patients for a given shift or period, the workforce management interface 106 may generate and display an alert 134 indicating that exception to a charge nurse or other manager. According to embodiments, in the event of an alert 134 the workforce management interface 106 may present the staff manager (or other user) with options for instance to temporarily accept an assignment to remedy the violation later, to cancel that assignment, to suggest alternative assignments, or take other actions or options. Other regulatory, compliance, clinical, operational, industry or other criteria or guidelines may be used, monitored or accessed to trigger alert 134 .
[0018] FIG. 4 illustrates overall management interface and workforce assignment processing, according to embodiments of the invention. In step 402 , processing may begin. In step 404 , the workforce management interface 106 or other clinical tool, interface, presentation layer or resource may be accessed, initiated or executed, for example by a charge nurse on or by client 102 or other networked or other machine or resource. In step 406 , the charge nurse or other staff manager may access or review the patient population profile 112 to assess or determine the clinical care needs of patients in a unit or other group represented in patient population profile 112 . Those clinical care needs may be or include specialized skill criteria 118 required to service the conditions or carry out the therapies of individual patients, such as for example training on or certification for types of equipment such as ventilators or pumps, electrocardiograms (EKGs), the training or certification to insert and administer intravenous lines, or other qualifications, skills, certifications or capabilities.
[0019] Those clinical care needs may likewise include provider coverage or assignment gaps, for instance depicted in assignment bar 120 as a white-colored or other coverage gap 122 indicating, for instance, that an assigned nurse, therapist or other care provider is scheduled to depart early on a given day, leaving four hours starting at noon or other periods of time for that patient uncovered or unassigned. Other care assignments and patient needs are possible.
[0020] In step 408 , the staff manager may review the provider population profile 124 to assess and determine available care providers and their projected or estimated capacities, skill sets and other information or qualifications to service the patient population. For instance, a charge nurse or other staff manager may use workforce management interface 106 to access the provider population profile 124 and review provider list 126 , provider capacity ratings 128 , provider schedule 130 and other information to assess the overall complement of provider capacity and capability available for assignment. According to embodiments of the invention in one regard, the provider capacity ratings 128 or other projected or estimated work capacity or production ratings may be generated by or accessed from a capacity platform such as that described in the aforementioned U.S. patent application Ser. No. 10/679,836, or other platforms, systems or resources.
[0021] In step 410 , the staff manager may assess and determine any requirement for specialized care needs, such as for example the assignment of common care providers to a mother and newborn infant. In step 412 , the staff manager may drag and drop or otherwise allocate or activate an assignment of a care provider to one or more patient requiring a care assignment, for instance selecting or highlighting a nurse, therapist, technician or other from provider list 126 and dragging that name or other object on top of a patient name in the patient list 114 . According to embodiments of the invention in one regard, upon acceptance of that selected assignment, the assignment bar 120 and other graphical displays or other information may be updated to reflect the newly assigned provider, and the period of time over which they may be assigned. According to embodiments of the invention in a further regard, the coverage gap 122 may automatically disappear when such an assignment may be made. In other embodiments of the invention, when a patient is selected in step 412 , the system may block off all or part of one or more assignment bars for the staff who are inappropriate based on the patient's rated needs and the provider's rated capacity.
[0022] In step 414 , an alert 134 may be generated and displayed on workforce management interface 104 upon the detection or identification of an assignment, attempted assignment or other action causing or leading to violation of compliance, clinical, operational or other criteria or limits, for instance upon detection of a skill set mismatch or other exception, or that the assignment of a nurse would result in a patient assignment total or ratio which would exceed federal, state, industry or other limits or guidelines. In step 416 , the workforce management interface 106 may in the event of an invalid assignment or other exception generate an alternative provider assignment which may remove the exception or other invalid condition.
[0023] In step 418 , the workforce management interface 106 may generate and display updated assignment, capacity, schedule and other data reflecting provider assignment updates or changes and other information, for instance via assignment bar 120 or other visual, graphical or other display. In step 420 , the set of provider assignments 132 may be stored to workforce database 108 or other data store or facility, for instance to distribute to the clinical staff, create a record of clinical operations, to serve as a basis for or input to a further set of assignments, or other purposes. In step 422 , processing may repeat, return to a prior processing point, jump to a further processing point or end.
[0024] The foregoing description of the invention is illustrative, and modifications in configuration and implementation will occur to persons skilled in the art. For instance, while the invention has generally been described in terms of generating and presenting a workforce management interface 106 which may be hosted on or displayed by a client 102 such as a desktop or laptop computer, in embodiments the workforce management interface 106 may be hosted on, executed by or displayed on other machines or resources, for instance on a network-enabled cellular telephone or digital assistant, a special-purpose workstation, or other hardware or resources.
[0025] Similarly, while the invention has in embodiments been described as involving the tracking and management of patient assignment configurations in a single unit 110 such as a single hospital floor or department, in embodiments the workforce management interface 106 may track, manage and provide a view on other units of operation or multiple units, such as a wing, laboratory, complete floor, or other workforce or workplace section or division, combinations of the same, or multiple or aggregated hospitals or other facilities. Other hardware, software or other resources described as singular may in embodiments be distributed, and similarly in embodiments resources described as distributed may be combined. For instance while the invention has in embodiments been described as storing patient assignment and other data to a single workforce database 108 , in embodiments patient data, provider data, patient to provider (or provider to patient) assignment and other data may be stored to single or multiple local, remote, networked or other databases or data stores. The scope of the invention is accordingly intended to be limited only by the following claims. | A system and related techniques generate and present a clinical workforce management interface to assign nurses, technicians, therapists and others in a hospital or other clinical setting. According to embodiments, the interface may present components including an aggregate patient population profile which lists individual patients in a unit, as well as the projected workload capacity the care for those patients represents as well as an assignment bar depicting the continuity of provider assignments for that patient over a shift, 24 hour, or other period. The workforce management interface may likewise present a counterpart provider population profile which lists available care providers in a unit, as well as their capacity ratings, skill sets, shifts or other schedule and other data characterizing available clinical stuff. According to embodiments of the invention in one regard, a charge nurse or other staff manager may visually or graphically view and manipulate the provider-to-patient assignments, for instance by dragging and dropping icons or other visual elements to perform assignments. According to embodiments of the invention in another regard, compliance monitoring functions such as maintaining mandated patient to nurse or other provider ratios may be automatically performed, and the staff manager may be alerted when those or other ratios or criteria violate limits. | 6 |
FIELD OF THE INVENTION
[0001] This invention relates generally to fencing. More specifically, to a fencing system that includes fence panels constructed and arranged to be pivoted to a horizontal position to prevent fencing damage from high winds and flying debris.
PRIOR ART BACKGROUND
[0002] The United States has experienced over 60 weather-related disasters in the past 25 years, each of which has caused in excess of $1 billion in damages. Together, these disasters have caused in excess of $350 billion in damage.
[0003] Population growth along the coastline of the United States has resulted in an increased risk to life and property from hurricane related damage. There are approximately 153 million residents that live in coastal counties of the United States, with areas such as Texas, Florida, and the Carolinas, where hurricanes frequently strike, experiencing rapid population growth. In addition, many coastal areas experience substantial but temporary population increases from holiday, weekend, and vacation visitors during hurricane season.
[0004] Homes, buildings, fences and other permanent structures often suffer substantial damage when windborne debris and storm generated winds overload the capacity of the structure.
[0005] Fences are often erected in congested areas to provide privacy and safety to the homeowner. In fact, many coastal areas have laws requiring fences to be built around swimming pools or yards that contain swimming pools to reduce pool related accidents. These fences are often constructed of wood, plastic, aluminum, steel or other structural material at great expense to the homeowner. The fences generally include a plurality of vertically oriented posts anchored within the ground and fence panels permanently affixed to and extending between the vertical posts. Due to the permanent and structural nature of fences, they are often damaged or destroyed by the strong winds generated in coastal storms.
[0006] Removal and storage of the fence panels before a storm is generally impractical. Most fences are not constructed to allow for disassembly without destroying the fence panels. Even if the panels could be removed, storage of the panels would be difficult and would consume a significant portion of the available storage space. In addition, the inherent weight of the fence panels would require a support structure to prevent the panels from tipping or falling while stored. Still yet, due to the congested population of coastal areas, many families live in condominiums or apartments. Most of these dwellings do not have a garage or other space which could be dedicated to fence panel storage.
[0007] Prior art fencing examples include, Itri et al., U.S. Pat. No. 4,465,262, discloses a portable expandable barrier which comprises a pair of fences slideably interconnected and releasably held in a desired orientation by locking means such as lock set cylinders. Nicholls, U.S. Pat. No. 5,364,076, discloses a fence structure including a barrier and elongated fence posts. The fence posts include T-shaped slots in which end portions of the fence sections are received prior to final assembly of the posts. In general these fences are constructed as permanent structures. Thus, removal of the panels to minimize storm related damage to the fence would require complete disassembly of the fence structure.
[0008] Therefore, what is needed in the art is a fence system that allows the fence panels to be pivoted to a substantially horizontal position during a storm which produces high winds. The fence system should provide brackets that are constructed for easy installation on pre-existing as well as new fencing. The construction of the upper retainer brackets should allow detachment of the upper portion of the fence panels from the posts while the lower brackets should be hinged so that the fence panels can be pivoted for securement to the ground in a substantially horizontal orientation. Stakes should be provided to secure the fence panels to a ground surface in their horizontal orientation. After the storm, the panels should be re-engagable to the posts in the vertical orientation to provide privacy and security.
SUMMARY OF THE PRESENT INVENTION
[0009] The present invention provides a fence system for homes, buildings and the like. The fence system according to the instant invention includes panels constructed and arranged to be pivoted between a vertical orientation and a horizontal orientation. When connected to permanently mounted posts in a vertical orientation, the fence panels may be utilized for privacy and/or security. Pivoting the panels to horizontal position during storms, such as hurricanes, reduces or eliminates the damage caused to the fence by high winds and/or windborne debris. The panels include hinged brackets mounted on the lower portions thereof which allow the panels to be pivoted between the two positions. Removable retainer brackets are secured to the mid and upper portions of the panels and the fence posts to maintain the panels in a vertical orientation. Removal of the retainer brackets permits pivoting the panels between the two positions. Hold-down assemblies are provided which cooperate with the ground surface and the panels to hold the panels in the horizontal position for storms. The hold-down assemblies prevent the panels from lifting during high wind situations. This construction permits the panels to be secured either in a vertical position with respect to the posts or in a horizontal position for protecting the fence from high winds and/or wind-borne debris.
[0010] Therefore, it is an objective of this invention to provide a high wind fence system.
[0011] It is another objective of the instant invention to provide a fence system capable of providing privacy as well as reduce or eliminate damage caused to the fence from high winds.
[0012] It is a further objective of the instant invention to provide a fence system which includes panels adapted to pivot for protection against high winds and wind-borne debris.
[0013] It is yet another objective of the instant invention to provide a fence having panels that are constructed and arranged for pivotal movement between a vertical position for privacy and a horizontal position for protection against high winds and wind-borne debris.
[0014] A still further objective of the instant invention is to provide a hinged bracket assembly and a retainer bracket member that can be used to convert a pre-existing fence into a hurricane fence.
[0015] Other objectives and advantages of this invention will become apparent from the following description taken in conjunction with the accompanying drawings wherein are set forth, by way of illustration and example, certain embodiments of this invention. The drawings constitute a part of this specification and include exemplary embodiments of the present invention and illustrate various objects and features thereof.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] While the novel features of the invention are set forth with particularity in the appended claims, the invention, both as to organization and content, will be better understood and appreciated from the following detailed description, taken in conjunction with the drawings, in which:
[0017] FIG. 1 is a front view, illustrating one embodiment of the instant invention wherein the fence panels are illustrated in a vertical orientation;
[0018] FIG. 2 is a side view illustrating one embodiment of the instant invention wherein the fence panels are illustrated in a horizontal orientation;
[0019] FIG. 3 is a partial side view illustrating a lower hinged bracket assembly which may be utilized to pivot the fence panels between a vertical and a horizontal position;
[0020] FIG. 4 is a partial side view illustrating a retainer bracket which may be utilized to secure a fence panel to a post in a vertical orientation;
[0021] FIG. 5 is a perspective view illustrating one embodiment of a hinged bracket assembly;
[0022] FIG. 6 is a perspective view illustrating a hinged bracket assembly for securement to two stringers;
[0023] FIG. 7 is a perspective view of a retainer bracket of the instant invention;
[0024] FIG. 8 is a side view of a hold-down member of the instant invention;
[0025] FIG. 9 is a front view of the hold-down member of FIG. 8 .
DETAILED DESCRIPTION OF THE INVENTION
[0026] While the present invention is susceptible of embodiment in various forms, there is shown in the drawings and will hereinafter be described a presently preferred embodiment with the understanding that the present disclosure is to be considered an exemplification of the invention and is not intended to limit the invention to the specific embodiments illustrated.
[0027] Referring to the FIGS. 1 and 2 , a hurricane fence system 10 is illustrated. The hurricane fence system includes permanently mounted posts 14 and at least one panel 12 that is constructed and arranged to be pivoted between a vertical orientation for privacy and a horizontal orientation for storm protection. FIG. 1 illustrates a preferred embodiment of the fence system 10 . The fence includes at least two spaced apart substantially vertical posts 14 . The posts having an upper portion 16 and a lower portion 18 , the lower portion is constructed and arranged to be secured to or within a ground surface 20 . The lower portion of the posts may be secured to the ground surface by any method well known in the art which may include, but should not be limited to, burying a portion of the post, setting a portion of the post in concrete, using fasteners or brackets to secure the post to a hard surface, weldment or any suitable combination thereof.
[0028] The panel 12 includes a lower stringer 22 , an upper stringer 34 and a middle stringer 36 , each having sufficient length to extend between a first end 30 and a second end 32 of the panel. A plurality of substantially vertical members 38 are secured to the stringers to provide privacy and/or security. In the preferred embodiment, the stringers and the vertical members are constructed of wood. However, it should be noted that the stringers and/or the vertical members may be constructed of any material suitable for use as fencing, such materials may include, but should not be limited to metal, plastic, concrete and suitable combinations thereof.
[0029] Referring to FIGS. 1-3 and 5 - 6 , secured to the lower portion of each post are hinged bracket assemblies 24 . The hinged bracket assemblies are generally constructed and arranged to cooperate with a post 14 and a lower stringer member 22 . The hinged bracket assembly includes a base 26 , a body 28 , and a hinge 30 . The base 26 includes a plurality of apertures 32 sized to accept fasteners for securing the base to a post 14 . The body is generally U-shaped to include two legs 34 , the legs are spaced and sized to extend substantially around the sides of the lowermost panel stringer 22 . The body 28 is suitable secured to the hinge to be pivotable about the hinge 30 for movement between a vertical position and a horizontal position. The hinged bracket assemblies 24 may be secured to the posts and the stringers by any suitable means well known in the art, which may include but should not be limited to, fasteners, adhesive, weldment, cast in place or any suitable combination thereof. FIG. 6 illustrates one embodiment of the hinged bracket wherein the body 28 is formed wide enough to cooperate with stringers of two adjacently positioned panels. FIG. 3 illustrates an alternative embodiment of the hinged bracket wherein the base includes an integral side support 27 . The side support provides additional weight capacity and resistance to high winds.
[0030] Referring to FIGS. 1-2 , 4 and 7 , the retainer members 40 are generally constructed and arranged to cooperate with the stringer members and the posts to selectively retain the fence panel 12 in a vertical orientation. The retainer members include a generally U-shaped body 42 with two tabs 44 extending perpendicularly from the ends of the upstanding legs 46 . In this manner the retainer body can substantially enclose the stringer to cause a reliable securement of the panel. The tabs include elongated apertures 48 sized for cooperation with studs 50 . Wing nuts 52 are sized to cooperate with the studs 50 for removable interlocking engagement. It should be noted that fasteners other than the stud and wing nut combination can be utilized without departing from the scope of the invention. Such fasteners may include, but should not be limited to, bolts, screws, bayonet type fasteners, magnets and suitable combinations thereof.
[0031] Referring to FIGS. 8 and 9 , the hold-down assembly 60 is illustrated. The hold-down assembly is generally constructed and arranged to cooperate with at least one and preferably two panels 12 oriented horizontally to substantially prevent the panels from lifting during high winds. The hold-down assembly includes at least one stake member 62 , a connector member 64 and a lateral member 66 . The stake member(s) 62 include notches or barbs 68 which cooperate with the ground 20 to prevent unwanted lifting of the hold-down assembly during use. The connector member is utilized to connect the upper portions of any number of stake members together so that they may be inserted or withdrawn from the ground as a single unit. The lateral member 66 is connected to the connector member or directly to the stake member to extend outwardly therefrom in at least one direction for engaging the panel assemblies 12 . In the preferred embodiment, the hold-down assembly is constructed from metal however, it should be noted that other materials suitable for securing a panel to a ground surface may be used without departing from the scope of the invention such materials may include, but should not be limited to, plastic, wood or suitable combination thereof.
[0032] Referring to the FIG. 2 , the panel is tilted to the horizontal orientation by removing the wing nuts 52 from the studs 50 . Thereafter, the retainer brackets are removed allowing the panel 12 to be rotated into a horizontal orientation. A hold-down assembly 60 may then be driven into the ground surface 20 between the distal ends of adjacent panels until the lateral member 66 contacts the panels to hold the panels in the horizontal orientation. The retainer members may be placed over the studs and the wing nuts utilized to store the retainer members on the posts. Moving the panels back to a vertical orientation requires the hold-down assembly to be pulled from the ground. The panels are moved manually back to the vertical position, whereby the stringers contact the posts. The retainer members are then placed around the stringers and over the studs. The wing nuts can then be replaced onto the studs and tightened to retain the panel in the vertical orientation.
[0033] All patents and publications mentioned in this specification are indicative of the levels of those skilled in the art to which the invention pertains. All patents and publications are herein incorporated by reference to the same extent as if each individual publication was specifically and individually indicated to be incorporated by reference.
[0034] It is to be understood that while a certain form of the invention is illustrated, it is not to be limited to the specific form or arrangement herein described and shown. It will be apparent to those skilled in the art that various changes may be made without departing from the scope of the invention and the invention is not to be considered limited to what is shown and described in the specification and any drawings/figures included herein.
[0035] One skilled in the art will readily appreciate that the present invention is well adapted to carry out the objectives and obtain the ends and advantages mentioned, as well as those inherent therein. The embodiments, methods, procedures and techniques described herein are presently representative of the preferred embodiments, are intended to be exemplary and are not intended as limitations on the scope. Changes therein and other uses will occur to those skilled in the art which are encompassed within the spirit of the invention and are defined by the scope of the appended claims. Although the invention has been described in connection with specific preferred embodiments, it should be understood that the invention as claimed should not be unduly limited to such specific embodiments. Indeed, various modifications of the described modes for carrying out the invention which are obvious to those skilled in the art are intended to be within the scope of the following claims. | The present invention provides a fence system for homes, buildings and the like. The fence system according to the instant invention includes panels constructed and arranged to be pivoted between a vertical orientation and a horizontal orientation. When connected to permanently mounted posts in a vertical orientation, the fence panels may be utilized for privacy and/or security. Pivoting the panels to horizontal position during storms, such as hurricanes, reduces or eliminates the damage caused to the fence by high winds and/or wind-borne debris. | 4 |
FIELD OF THE INVENTION
The present invention relates to a machine for removing or stripping materials such as shingles from a roof deck and more particularly relates to a motor driven deuce of this type, sometimes referred to in the roofing industry as a motorized spud shovel.
BACKGROUND OF THE INVENTION
Residential and commercial building construction generally have roof decks which are covered with a protective layer of shingles or other roofing material. Shingles are generally placed in overlapping, aligned rows and the shingles are secured in place by a combination of adhesives, nails, staples or other fasteners. Another conventional roof construction is the built-up roof in which utilizes rolled roofing material having an asphaltic base which is laid in strips in overlapping or abutting relationship. The strips are secured to the deck by use of adhesives or fasteners. Periodically, as weathering occurs, it becomes necessary to remove the old roof covering and replace the roofing material with new material. Accordingly, various tools and apparatus can be found in the prior art to assist roofers in stripping the old material from the roof deck.
A tool commonly used for this purpose is a simple flat edged shovel which is manually forced under the shingles and rips the shingles and fasteners from the roof deck. Other improved manual devices can be found as, for example, U.S. Pat. No. 4,466,188 which shows a manual roofing remover having a wedge-shaped head. Motorized devices for removing or stripping roofing material are also known.
U.S. Pat. No. 4,277,104 shows a power-driven device for removing shingles from a roof surface which has a reciprocating plate having a notched forward end that moves along a concave arc during reciprocation.
U.S. Pat. No. 4,691,439 shows a powered apparatus for stripping shingles which is shovel-like having a blade and slots. Power means lower and raise the blade so that when the blade is lowered it moves under the shingles. The blade is then raised to exert leverage and detach the shingles and the slots engage the nails to pull them out.
U.S. Pat. No. 4,663,995 shows another shovel-like device for removing roofing material having a lifting blade including a blade-like leading section and a trailing section. Actuator means in the form of a cylinder will depress the trailing section of the lifting plate to rotate the lifting plate pulling fasteners and roofing material away from the roof deck.
U.S. Pat. No. 4,763,547 discloses a shingle stripping tool having a frame and a power head. The power head has a fulcrum and lift plate for articulating movement about a pivot axis. A pneumatically powered drive pivots the lifting plate.
U.S. Pat. No. 4,756,578 discloses an apparatus for removing shingles which has a mobile frame and has a blade pivotally attached to the front end of the frame. The blade is movable between an upper and lower position. An air cylinder will selectively lift the blade from the lower position to the upper position. As the blade is advanced, the blade is wedged between the roof shingles and roof deck.
U.S. Pat. No. 4,837,993 describes a machine which travels over the roof surface and has a separating structure reciprocally positionable between a forwardly directed separating engagement position with the material and a lifting position. The drive has an eccentrically configured cam which periodically or reciprocally engages a portion of the separating means causing its reciprocal and pivotal movement relative to the frame.
U.S. Pat. No. 5,001,946 discloses an apparatus for removing shingles which includes an elongate body with a handle and a pivotally connected lift plate at the lower end. A piston and cylinder are activated by a trigger. The lift plate is pivotally mounted and a toggle linkage connects the actuator to the lift plate pivoting the forward edge of the plate about a heel structure.
Thus, from the foregoing, it will be seen that there are numerous manually operable and powered devices for removing shingles. While some of the devices are effective, they generally have not achieved acceptance within the industry for a number of reasons. Often the devices are cumbersome and heavy and are not convenient to use on a roof. Another disadvantage of prior art devices is that they often operate simply to raise and lower to remove shingles. In other words, the devices do not operate in a manner which effectively "stabs" the interface between the roof deck and shingle and thereafter lifts the shingle and "pops" any mechanical fasteners and then will withdraw to escape debris.
Thus, from the foregoing, it will be apparent that there exists a need for an effective shingle/roofing material removing device which is convenient to use. While the present invention is described with reference to a roofing material stripping device, it will be apparent that a device of the type to have other applications such as removal of flooring material such as a carpet, tile or any other application where a layer of material is to be stripped from an underlying substrate.
SUMMARY OF THE INVENTION
The present invention constitutes an improvement over prior art motorized shingle removers which are sometimes referred to as "spud" shovels. The device of the present invention has an elongate handle with oppositely extending grips at the upper end. A power transmission includes one or more axially extending drive shafts which are operatively connected to an air motor. The lower end of the drive shafts each carry a bevel gear which engage corresponding gears on a drive wheel which drive wheel is mounted on a transversely extending horizontal axis. The outer surface of each drive wheel carries an eccentrically mounted pivot pin. The drive wheels are connected to a blade by a pair of forwardly extending links or arms. The forward end of the blade serves to effectively remove shingles, building materials and fasteners. One or more wheels support the device to allow the operator to manually advance and retract the device.
The blade carries a fulcrum having feet or a skid plate which engages the roofing surface. The fulcrum is axially slidable along a forwardly extending shaft at a sleeve arrangement. When the operator activates the motor, the transmission will rotate the drive wheels causing the forward end of the blade to move in a generally circular path in which the blade stabs the interface between the roofing material and the roof deck and then rotates upwardly and rearwardly to remove the material and any fasteners and also to rotate free of the debris. Once the blade has exerted leverage to detach shingles and nails in an area, the apparatus can be rocked or moved forwardly by the operator on the wheels.
In an alternate embodiment, the power transmission includes a motor having an output shaft which, directly or indirectly through a gear set, drives the drive wheels:
The above and other objects and advantages of the present invention will become more apparent from the following description, claims and drawings in which:
FIG. 1 is a perspective view of the machine of the present invention with the machine shown connected to a source of pressurized air;
FIG. 2 is an elevational view of the front end of the machine with arrows showing the reciprocatory motion that is imparted to the forward end of the blade to stab, lift and rotate free of debris;
FIG. 3 is a top view of the machine of the present invention partly broken away to better illustrate the components;
FIG. 4 is a enlarge detail view of the upper end of the handle and grips, partly broken away for clarity;
FIG. 5 is a detail view of a portion of the drive mechanism or transmission as indicated in FIG. 3;
FIG. 6 is an enlarged, perspective view of the front end of the machine and the blade;
FIG. 7 is a sectional view taken along line 7--7 of FIG. 6;
FIG. 8 is an exploded view of the fulcrum and blade support assembly;
FIG. 9 is a perspective view of an alternate embodiment of the roofing material stripping machine of the present invention; and
FIG. 10 is a side view of yet another embodiment of the present invention.
DESCRIPTION OF THE INVENTION
Referring to the drawings, the device of the present invention is generally designated by the numeral 10 and has a pair of elongate, tubular handles 12 and 14 which are joined at their upper end to a housing 16 having oppositely extending grips 18 and 20. The lower end of the handle members 12 and 14 terminate at housing member 22 which is supported for movement on wheels 28 and 30. A blade 32 is supported on fulcrum assembly 36 and, as will be explained hereafter, is driven in a rotating and reciprocal path to efficiently remove material such as shingles.
As best seen in FIGS. 3 and 4, the handle members 12 and 14 are hollow and have internal bearings 19 for supporting rotating drive shafts 40 and 42 which are respectively provided with bevel gears 46 and 48 at their upper ends. Transversely extending grips 18 and 20 extend from the housing 16 at the upper end of the handle. A shaft 50 extends transversely within the grips and is mounted in suitable bearings 25. A pair of gears 52 and 54 are provided at spaced-apart locations along the shaft 50 and are in driving engagement with gears 46 and 48, respectively. Suitable drive means are provided to impart rotation to shaft 50. The drive means may be electrical or mechanical or, as shown, an air motor 58 of conventional design may be provided within the grip 18 and the output shaft of the air motor coupled to shaft 50. Air motor 58 is connected to a suitable source of pressurized air 60 by means of air hose 62 at quick disconnect coupling 64.
The exterior of grips 18 and 20 may be knurled or provided with a resilient covering for the comfort and convenience of the user. The gear motor is actuated by means of a trigger 35 on grip 18 adjacent housing 16.
The lower end of the drive shafts 40, 42 terminate at a pair of bevel gears 60 and 62. A tubular frame member 65 extends intermediate the handles 12 and 14 and projects from the forward end of the housing 22. The tubular frame member 65 is formed having a slight angular configuration so that when the lower end of the tube 65 is substantially parallel with the working surface, the handles 12 and 14 extend rearwardly and upwardly at an angle of about 30° to 45° with respect to the working surface placing the grips at a convenient height for the user.
As best seen in FIG. 5, a journal 68 extends transversely of tubular member 65 within the housing 22. Shaft 70 is rotative within the journal 68. The opposite ends of the shaft 70 are threaded to receive drive wheels 60 and 62 which are secured by appropriate washers and fasteners 75.
The interior faces of the drive wheels 60, 62 each have teeth 75 which are in driven engagement with the bevel gears 72 and 74 at the lower ends of the drive shaft. Thus, it will be seen that when the air motor is actuated, the power transmission consisting of shaft 50, drive shafts 40, 42, and shaft 70 transmit rotary motion to drive wheels 70, 72.
The blade or shovel 32 has a leading edge 80 which engages the material to be removed and the fasteners. The blade is preferably of a suitable durable material such as a high carbon steel and is provided with an axially extending upwardly projecting central dome 81 which assists in shedding material from the upper surface of the blade. Rearwardly extending arms 84, 86 are pivotally attached to the drive wheels 60, 62, respectively, at pivot shafts 88. Pivot shafts 88 are shown as bolts which are in threaded engagement with internally threaded bores in the drive wheels. The location of the pivot shafts 88 is radially offset from the central transverse axis of the wheels so that as the drive wheels rotate, reciprocatory circular motion, as seen in FIG. 2, is imparted to the leading edge 80 of the blade.
The blade or shovel 32 is supported by a fulcrum assembly 36 which has a pair of generally V-shaped fulcrums 100, 102. The fulcrum assemblies are best seen in FIG. 8 and each of the fulcrums 100, 102 has an arcuate section 104 from which a pair of diverging arms 106 and 108 extend terminating at flanges 110 and 112. The flanges 110, 112 are secured to the underside of the blade 32 within the area of dome 81 by welding or appropriate mechanical fasteners.
Since the eccentric motion imparted by the drive wheels imparts both a reciprocating and a rotary motion to the blade, the fulcrum must be allowed to axially reciprocate. To accommodate this motion, a sleeve 120 is slidable along forwardly extending shaft 122 which shaft has a stop 124 at its outer end. A transverse axle 130 is secured as by welding to the underside of the sleeve 120 and the arcuate sections 104 of the fulcrum members receive the opposite ends of the axle. The assembly is completed by snap rings 132 and 134 which are received in annular grooves 135 at the opposite ends of the axle 130.
A better understanding of the present invention will be had from the following description of operation.
The machine of the present invention is positioned on the surface from which material is to be removed such as a shingled roof. The operator positions himself or herself behind the machine. The machine is connected via air hose 62 to a source of compressed air 60. The operator grips the handle and may advance the device on wheels 28 and 30. The device is actuated by depressing the trigger 16 which will energize the air motor 58 causing the output shaft 50 to rotate. The rotation of the output shaft imparts rotation to parallel drive shafts 40 and 42 which, in turn, imparts rotation to the drive wheels 60 and 62. The rotation of wheels 60, 62 will transmit an oscillatory and reciprocal motion to the blade as seen in FIG. 2. The blade 32 reciprocates with sleeve 120 along the forwardly extending shaft 122. The fulcrum assembly 36 also moves back and forth along the work surface as the forward or leading edge of the blade 80 rotates and reciprocates.
The operator, by use of the grips, advances the leading edge 80 of the blade beneath the roofing material to be removed. As the leading edge 80 contacts the underside of the shingles, the shingles and any fasteners are lifted upwardly along with the fastener such as staples or nails. After the leading edge has lifted a section of shingles from the surface, the blade continues in a rearward motion free of the debris. The operator then proceeds forwardly so that the blade is positioned between the next remaining layer of shingles and removal is accomplished in a similar manner. The operator can proceed rapidly and safely as removal is accomplished by the power means rather than by manual application of force.
The device is effective to remove roofing material and securing fasteners in a single operation. The reciprocal and rotational movement of the leading edge of the blade removes the shingles and removes the blade clear of the debris preventing strip material from accumulating in the working area in the path of the machine. The dome shape of the blade keeps material from accumulating thereon as material is shed from the blade. Although not recommended, the machine can be operated with one hand, use of the machine significantly decreases manpower needed to strip a roof.
An alternate embodiment of the roofing machine of the present invention is shown in FIG. 9 which is generally designated by the numeral 200. The embodiment of the invention of FIG. 9 has an elongate tubular handle 212 with oppositely extending grips at the upper end of the handle. The lower end of the handle is configured having a generally rectangular frame member with longitudinally extending arms 218 which support a transverse axle 230 at the lower end. The device is supported for movement on wheels 228 carried on transverse axle 230.
Blade 260 is similar or identical in construction to blade 32 described above and shown in FIGS. 6 and 7. The blade has a leading edge 262 having notches 264 which engage the material to be removed along with the fasteners holding the material. The blade is preferably made of a suitable material such as a high carbon steel and has an axially extending central dome 265. Rearwardly extending arms 284 and 286 are pivotally attached to drive wheels 272 and 274 at pivot shafts 288 which pivot shafts are radially offset from the central transverse axis of the wheels so that as the gear wheels rotate, reciprocatory circular motion as seen in FIG. 2 is imparted to the leading edge of the blade. The gear wheels are commonly carried on a transverse axle 231 which is suitably mounted in journal bearings at a location within or secured to frame members 216 and 218.
Shaft 231 carries a gear 250 shown as a bevel gear which is in engagement with gear 255. Gear 255 is carried on the output shaft of air motor 235. The output shaft of the air motor is secured for rotation in suitable bearings at frame member 216. The air motor may be of any suitable conventional type and is connected to a pneumatic source 261 by air line 263 which extends along the upper grip handle 212 and frame member 218 to the motor. As has been described above, a suitable actuator switch is provided on the handle to allow the operator to control the machine by selectively directing air to the air motor.
The blade 260 is supported by a fulcrum assembly 290 which is essentially identical to the fulcrum shown in FIGS. 6 and 7. To accommodate the reciprocating rotary motion of the blade, a sleeve 295 is slidable along forwardly extending shaft 222 which is attached to shaft 231. The device of FIG. 9 operates in a manner essentially the same as has been described above with reference to previous drawing figures. The device is connected by an air hose 263 to a source of compressed air 261. The device is actuated by manually depressing the switch or trigger imparting rotation to gear 255 and driven gear 250. The rotation of gear 250 imparts rotation to shaft 231 which causes drive wheels 270 and 272 to rotate. Rotation of the drive wheels will transmit oscillatory reciprocal motion to the blade.
As the leading edge 262 of the blade contacts the underside of the roofing material, such as shingles, the shingles and any fasteners are lifted upwardly. The notches 264 assist in removal. After the leading edge of the blade has lifted a section of the shingles, the blade continues in a rearward motion free of the debris. The operator proceeds in this manner to remove remaining shingles. The device decreases the labor required for removal of roofing materials.
While the device is shown as being pneumatically operated, other power means such as an electric or hydraulic motor, could be used to provide the necessary power to the blade. However, it is conventional that roofers have a source of pneumatic power available since pneumatic-driven nailing guns are in common use.
In FIG. 10, another embodiment of the invention is shown which is generally designated by the numeral 300. It will be appreciated that this view is a right side view and that the left side view is a mirror image thereof. The machine has a handle 312 which supports a frame 318 having forwardly projecting arms 300. The machine is supported for movement on rear wheels 332 and intermediate wheels 334. Front wheels 336 are reciprocable on arms 320 at linear bearing 335.
The machine is powered by a motor 340 which may be hydraulic, pneumatic or electric with controls suitably located on the handle. The output shaft 342 causes drive wheels 350 to rotate. The drive wheels 350 are connected to the opposite sides of blade assembly 360 at pivot shafts 362. The drive wheels may be non-circular and weighted as a counterbalance to provide smooth rotation. Rotation of the drive wheels will cause the blade assembly 360 to reciprocate to remove roofing material and fasteners. The blade 365 is concave at 380 and includes a rearwardly mounted brush 382 to assist in sweeping away and removing debris.
The weight, design and configuration of the device allows the operator to conveniently transport and use the device. Another advantage is that the device allows the operator to work in a substantially erect position reducing stress and strain on the operator, particularly reducing the possibility of back injury.
While the principles of the invention have been made clear in the illustrative embodiments set forth above, it will be obvious to those skilled in the art to make various modifications to the structure, arrangement, proportion, elements, materials and components used in the practice of the invention. To the extent that these various modifications do not depart from the spirit and scope of the appended claims, they are intended to be encompassed therein. | A shingle stripping tool having a wheel supported frame including a rearwardly extending handle with a grip at the upper end. A power transmission includes a drive shaft extending along the handle which is driven by a motor. A reciprocally driven blade is supported on a sliding fulcrum. The blade is connected to the gear wheels at an eccentric arrangement whereby the blade is driven in a reciprocal and rotating motion to strip and clear debris. | 4 |
TECHNICAL FIELD
This disclosure generally relates to databases and in particular it relates to a novel database with an architecture involving method of creating and accessing databases.
BACKGROUND
There are many ways in which databases are currently architectured. The two main ones are: RDBMS (relational databases), ODBMS (Object databases). Both systems have been in existence for considerable length of time. RDBMS has enjoyed wider popularity than the ODBMS systems. However both have drawbacks.
Relational database management systems are widely used across industries to store and manipulate data. One of the main problems with relational databases has been the structural rigidity of data once defined using a data definition language (DDL). This has forced data to converge into silos of information each bounded by their own schema definition and each schema constructed for a specific purpose. This lack of integration has prohibited applications from taking advantages of the complex relationships between data from disparate sources and necessitated redundancy of data. The complexity of Online Transaction Processing (OLTP) vs. Online Analytical Processing (OLAP) systems and the conversion process between them is a direct case in point.
Some of the drawbacks of the RDBMSs are:
1. In case of the systems that use database cursors it is found that:
Application developers need to understand that the underlying data can change between the times that data records are accessed via the cursor: previously retrieved records may have been deleted, records may have been inserted into previously retrieved portions of the result set, or previously retrieved records may have been modified. Not all cursors are created equal. Some cursors only allow forward scrolling. Cursors are a resource drain on the database because they are memory intensive.
2. In case of systems using Java Virtual Machines, it has been found that:
Different version of VMs between application server and database server increases complexity of development. Behavior implemented in the database can easily become a bottleneck.
3. RDBMSs use triggers. There are drawbacks associated with these:
Hand-crafted, or hand-modified, triggers can be difficult to maintain and will increase your dependency on your database vendor. Triggers are typically implemented in a proprietary language requiring an extra skill set on your team. Because triggers are automatically invoked they can be very dangerous (such as “uncontrolled” cascading deletions resulting from chained delete triggers). Behavior implemented in the database can easily become a bottleneck if your database doesn't scale well.
Another problem area while using RDBMSs is coupling. Coupling is a measure of the degree of dependence between two items—the more highly coupled two things are the greater the chance that a change in one will require a change in another. Coupling is a major challenge when it comes to software development, and the more things that your database schema is coupled to the harder it is to maintain and to evolve. Further challenges that one faces with RDBMSs are:
1. Data integrity is difficult to ensure with shared databases. Because no single application has control over the data it is very difficult to be sure that all applications are operating under the same business principles. 2. Operational databases require different design strategies than reporting databases. The schemas of operational databases reflect the operational needs of the applications that access them, often resulting in a reasonably normalized schema with some portions of it denormalized for performance reasons. Reporting databases, on the other hand, are typically highly denormalized with significant data redundancy within them to support a wide range of reporting needs.
Many of these issues exist because of the nature of the database architecture.
Thus, a database system that is fundamentally different in its architecture may overcome the drawbacks mentioned above.
Some drawbacks of the ODBMSs are:
1. Rigid schemas with constraints need to be defined in advance. 2. All instances of objects have same predefined properties. 3. OLAP processing is inefficient.
There is therefore a need to provide a database that successfully addresses the various drawbacks of the existing database models, and provides a robust, flexible, and secure database.
SUMMARY
A non-relational transactional and analytical database is described. It has a novel data architecture that allows data to persist without requiring any schema definition. The database also provides a file system with in-built versioning, reliability and security and can be deployed in a distributed environment. The approach adopted is to break down data into its fundamental atomic components, called memes, and use a special type of graph (utilizing non-standard vertices and edges) to create logical relationships, represented by links, between these components. The database operational functionality is deployed through an application program interface (API). The underlying query language is based on recursive triplets of the form (subject, verb, object) and can be easily augmented with different query parsers, which translate from some source syntax to this syntax. The memes and links are identified with Universally Unique Identifiers (UUIDs). Additionally, the database also provides file system manipulation functionality through the use of UUIDs.
BRIEF DESCRIPTION OF THE FIGURES
FIG. 1 shows the class diagram of the database.
FIG. 2 shows the ontological model of the database.
FIG. 3 shows the file system model of the database.
FIG. 4 shows the database architecture for use with Example 1.
FIG. 5 shows a generalized flowchart for the query processor.
FIG. 6 shows the flowchart for security operations.
DETAILED DESCRIPTION
The database described below is an integral part of an overall architecture that comprises a database, and a security layer wrapped in an application program interface (API).
Structure of the Database
The database is based on a unified data model wherein the source data is split into its fundamental atomic components. In the database of the present invention, these fundamental atomic components are called memes. A meme is therefore defined as the fundamental indivisible unit of data. Memes are similar to a single cell in a table of a conventional database.
Memes can be logically bound together with other memes to create relationships which are called links. Links only exist in association with memes or other links. Each link has a subject, object and a verb associated with it. The subject, object, or the verb can be a meme or another link. It is important to note that each of these attributes, i.e. that of being a subject, an object, or a verb, is a property of a link and not specific to memes. For example, a meme can be a subject in one link and an object in another. It is a feature unique to the database that one or more of the subject, verb and object of a link can be another link (i.e. it is not limited to memes alone)
For the purpose of further discussion an entity called ‘neuron’ is defined. As shown in FIG. 1 , a ‘neuron’ is defined as a class comprising of two subclasses—‘meme’ and ‘link’. Since memes and links are both subclasses of a master ‘Neuron’ class, the definition of a link can be restated as a three-way relationship between neurons. Note that this allows recursive links.
The architecture of the database is described next. The memes are defined in terms of canonical names and aliases. The database, G, is defined as a union of a set of memes, M, and a set of links, L. Each meme has a set of aliases of which exactly one is the name. All instances, x, of neurons are assigned a unique global identifier UUID(x). Although we use UUIDs for the purposes of this discussion, any unique identifier can be used. Relationships between the neurons are defined through links such that each instance, x, of a neuron is represented as a subject or an object or a verb of a link. This is achieved through definition of inverse functions, LS, LO, and LV for subjects S, objects O, and verbs V respectively. This implies that for any link (l) where S(l) is x, LS(x) is a set of links of which the link l is a member. The same pair of inverse functions apply to O and V such that O(l)=x implies that l is an element of LO(x) and V(l)=x implies that l is an element of LV(x) It should be noted that LS, LO, and LV are defined for all neurons (i.e. for each meme or link), however, S, O, and V are defined only for links, thereby making the memes leaf nodes (i.e. the database's smallest units that cannot be divided further).
Since neurons are internally referenced solely via identifiers, a mechanism is required for resolving names and aliases into neurons. Hence, a case insensitive index is defined as a mapping between aliases of the neurons and neuron identifiers.
Database Query Engine
A user wishing to locate an instance of a meme or a link needs to search the database. This is facilitated through a query engine comprising of a query parser and a query processor, the grammar and algorithm for which is defined below:
Q→M|L 1
L→(Q, Q, Q)|function(Q, Q, Q) Each query Q consists of either a meme query, M, or a link query which is 3-tuple of queries, L, (each of which are meme queries or nested link queries) which represent the subject, verb and object in a link). L may also optionally contain a function modifier to be applied to the result of the query. This is useful when using nested link queries. The meme query can be the identifier of a link, a wildcard (*), an alias (which will return all links having that alias), a partial alias containing one or more wildcards (*), a numerical range separated by the colon literal (:) e.g. 2:45 or a boolean expression containing a combination of the above. 2. Meme queries are resolved via direct lookups into indexes. In case the expression is an identifier, no resolving is required, for expressions containing aliases, the alias-to-identifier index is used. Other expressions can use any index defined by the implementation (e.g. B-tree, hash table, suffix tree, Patricia tree, R-tree). 3. The query algorithm matches link queries in the following manner. For each sub query Qs, Qv and Qo, a set of candidate links is computed by taking the union of the set LS(x), the union of the set LV(x), the union of the set LO(x) for each neuron (x), in Qs, Qv and Qo. The result is the intersection of these three sets.
In traditional databases, cursors, which are pointers to rows of data within a database table, are used to navigate the table. The database does not have tables, therefore cursors are not relevant. The database therefore advantageously avoids the problems associated with cursors, which have been discussed in the prior art section.
Any data navigation scheme must allow easy movement between memes and links. Although this is fully possible with the Basic API and query methods, they can sometimes become syntactically verbose and conceptually complex to maintain. The database uses “ideas”, which are a high level solution to this problem. An “Idea” is another class. Groups of neurons can be converted into a single idea for easy representation and manipulation. Each instance of an idea (i) is characterized by a primary neuron (x), which it represents. This instance, has attributes corresponding to the verb-neurons of all links in which x participates as the subject. Further, the values of each such attribute is the object of the corresponding link. Hence, an “idea” gives a complete representation of the neuron in the database. Ideas can then be converted into an alternate representation, which contains attributes within a limited domain for the purposes of consumption by an application.
During the navigation of conventional databases, the cursors need to store entire tables in memory, leading to performance overheads. One of the advantageous features of the database architecture is that the navigation mechanism based on the idea concept needs to store only the data related to the idea of the neuron under consideration. This results in small navigation-time memory requirement thereby making the navigation operation highly scalable.
Furthermore, the navigation mechanism has further advantage over the cursor-based schemes. This has to do with navigation-time modifications to the database. These are not easily possible with the conventional systems, whereas the ideas-based systems have no such restrictions. Setting the value of an attribute automatically creates the memes/links in the database. Moreover, transaction support is in-built. Changes are only committed to the database when the user calls the ‘save’ method of an “idea” instance.
We will now illustrate another advantageous aspect, which has to do with the state of consistency of the database. Consider two ideas, a and b such that b is an attribute of a. This implies that the neuron referenced by b is participating as the object in a link where the neuron referenced by a is the subject. This means that the definition of a is dependent on b but b is not dependent on a. When the idea a is saved, b is saved automatically. However, separately saving b has no impact on a. This mechanism prevents the database from being in an inconsistent state
Hence “ideas” are fully compatible with the object API and provide a natural transition to an even higher object oriented abstraction layer of database access.
Ontology
FIG. 2 shows the ontology of the database.
Suppose we wish to represent a simple entity (Person) with two attributes (name, email). In a typical relational database, this would be done in the schema using a table (person) for the entity with two columns (name and email) each with pre-specified data types. This would then apply to all instances (rows) of persons in the database.
Suppose we have an instance of Person, Prateek with email, ps@brainwavelive.com. This is represented with the pseudocode as below:
Person x=new Person()
x.name=“Prateek”
x.email=“ps@brainwavelive.com”
In the database, this same thing is broken up into a two step process. First, we create the basic raw-materials. Since we shall represent Person, name and email in the database, we create memes for each of them. Further, we create memes for each type of relationship between these memes. e.g. Prateek is a Person, Prateek has attributes and Prateek has name is Prateek. Hence, we create memes for “is a”, “has” and “is”. These can be used as verbs to denote similar relationships all through the system.
Finally, we create two memes for the data: “Prateek” and “ps@brainwavelive.com”. At this point, although the database contains all the data, it is unusable without the logical relationships. The first thing to do is to pick a meme for the canonical name of the object. In this example, we pick “Prateek” as the canonical name although it is feasible to use an auto generated id. First we create a link with subject “Prateek”, and object “Person”. Since the purpose of this link is to denote that “Prateek” is a hyponym of “Person” and “Person” is a hypernym for “Prateek”, we use the “is a” meme as the verb. This gives us the link (Prateek, is a, Person) with each element in the ordered 3-tuple or a triplet representing the subject, verb and object respectively. Hence we can begin to create an ontology for Prateek.
Continuing with the exercise, we now need to represent the two attributes of Prateek (i.e. name and email). One of the most important things to note is that the database advantageously related the name and email directly to the data itself and not to the specification of Person. The unique structure of the database advantageously eliminates the need for inference rules such as if Person has name and email, then everything which “is a” Person also must have a name and email. Hence, we would create two more links:
(“Prateek”, “has”, “name”), and
(“Prateek”, “has”, “email”).
These links sufficiently state that Prateek has the attributes name and email. Elaboration of what the actual values are is carried out using the unique recursive properties of the database. We do this by creating two links represented by:
((“Prateek”, “has”, “name”), “is”, “Prateek”), and
((“Prateek”, “has”, “email”), “is”, “ps@brainwavelive.com”)
In both these links, the subject is another link, with their own 3-tuple structure. This is permissible since in definition of l εL, S(l)εM∪L, V(l)εM∪L, O(l)εM∪L.
As another advantageous feature of the database, this architecture enables us to do more without the need for any more architectural constructs. For example, consider the following links, which represent some rules for database access:
((“Prateek”, “has”, “name”), “is a”, “string”), and
(((“Prateek”, “has”, “name”), “has”, “read only”), ‘is’, ‘true’).
An important point to note here is that creating these links is pointless since it does not make these rules enforceable universally. There is no mechanism defined to enforce these rules for all authors and guarantee the same for consumers. Authors are free to add attributes at will and consumers are expected to use ideas or else write generalized programs which first query the database to find available attributes. This flexibility is a unique advantageous feature of the database which enables authors and consumers to share data without the need for direct collaboration.
There is another way to model the information into the database, which is explained with the help of another example.
Let us try and model into our database that John lives in New York City. We create the database by creating relevant neurons. John and New York City are the minimum memes that we need to create. In addition, the concept of living somewhere can be represented as yet another Meme. This is done by creating another meme which can perhaps simply be called “lives in” or as the attribute name “city” which is yet a third meme.
The database assigns for each neuron a UUID which can be used to uniquely identify it. As shown in FIG. 4 , which show that the words “John”, “city” and “New York City” are simply aliases which point to the relevant UUIDs as represented by Index 1 .
We require a fourth neuron which will be the Link (l) which binds the various memes together. Hence, a Link is created whose subject is the meme “John”, verb is the meme “lives in” or “city”, and object is the meme “New York City”.
Hence the relationships are represented as subject
S(l)=Meme “John”;
verb V(l)=Meme “city” or the meme “lives in”, and
the object O(l)=meme “New York City”.
In addition,
LS(Meme “John”)=set(l),
LV(Meme “city”)=set(l),
LO(Meme “New York City”)=set(l)
This completes our modeling.
Modifiers
Often there is link-specific information related to the subject, object or a verb of a link. These pieces of information, also described as modifiers or adjectives, which are only relevant in the context of the link, serve to further describe the subject, object or the verb that they apply to. Simply put, modifiers allow users to enhance links with richer, relation specific information. Each modifier belongs to the neuron class and hence is either another meme or link. Modifiers are independent of each other and the list of modifiers is unordered.
For example, modifiers are used to logically delete or negate links. Adding the “not” neuron as a verb modifier in any link can be interpreted as logically negating the link.
Application Programming Interface (API)
It is possible to abstract database calls into object persistence model through a conventional object relational broker (ORB). Although the database is not a true object-database, it provides a similar application programming interface (API). The API is superior to the conventional ORBs because it does not have to deal with the schema constraints of conventional databases. This allows the object definition to vary from application to application with the database storing the superset of data at all times. This makes the interface much richer since each application is able to use its own object specification. The APIs that interface with databases use numerous calls while interfacing. Among the other calls available, the API exposes two major calls that are described below:
1. G ET : This call takes either the canonical name for a meme or its identifier. It then retrieves all attributes of the meme, and creates an idea instance and populates its properties with the attributes of the meme. The idea instance is returned. 2. P UT : The second call takes an instance of a class and uses introspection to identify all attribute names and values of that instance. It then serializes this information recursively (since attribute values may be other instances) using the basic API by converting attribute names and values to memes and relations between them into links. 3. G ET V ALUE : This call accepts a user-defined class definition as a parameter and attempts to return the most complete view of the meme as an instance of that class. If the class definition doesn't support an attribute of the meme, it is ignored. This allows applications with limited scope to take a myopic view of the memes in consideration.
Additional Features of the Database
There are several other advantageous features described below.
File System Operations
The database also supports the storage of binary data using a UUID system. FIG. 3 shows the file system model. A single meme may or may not point to a file. Links cannot point to a file. The name of a file is same as the UUID of its meme. All file system metadata related to the file (i.e. extension, file type, creation date and date of last access) is stored in a dictionary (along with other, user defined metadata) within the meme. Actual data of the file is stored on the underlying file-system.
The database also uses the meme/link mechanism to provide native versioning of the file system. New versions are represented as objects in a link where the subject is the old version. Even newer versions can reference the last version or the original copy (as required by the user). Hence, this simple scheme can be used to implement a flat, hierarchical or multi-dimensional versioning scheme as per the needs of the user. Although a special API call is provided for convenience, retrieving existing versions is carried out using the standard query mechanisms.
Finally, adding and retrieving files is also possible with the file system operations of the database. The adding of files is carried out through an API call that expect the UUID of the meme in which the file is to be saved, a structure containing the attributes of the file and the file data. The retrieval of files is carried out through a special function that expects the id of the meme and returns the file data stream.
Data Security
The database also provides a built-in security mechanism with meme level resolution. Most data in a collaborative environment (multi-user access) is considered public information hence by default all memes are left unlocked or open to user access. Individual memes can be blocked off from access by participating in the security models. Participation in security model levies an overhead and is left to a user's deliberate choice. Security is imposed through a two tier model comprising a capabilities tier and a policies tier. The capabilities model is an evolutionary replacement for the traditional permissions model. This is widely accepted to be safer model by a person skilled in the art than a traditional model based on permissions and access control.
FIG. 6 shows a flowchart for the security operations of the database.
The security system of the database architecture is represented in terms of actors, a, and resources, r. Users, applications (or anything else represented by a meme) assumes the role of an actor. Each actor has a global security context which stores keys (capabilities) to various resources (other memes). This is advantageously different from the conventional permissions based system where access control data is stored in the resource (as opposed to the actor). In the database architecture, the mere possession of a capability is implicit implication that an actor is authorized to access a resource.
An actor, represented by a meme, refers to an account of any user (human or computer program) that is able to access the database. Actors get a secure view (referred to as a context) of the database. Within the context, users are able to access secured resources. Actors and resources are both represented by memes. Hence it is also possible for the meme of an actor to behave as a resource in some other context. A simple example of this would be a computer program which is owned by a human user. Both are represented by memes which are actors, and hence enable both actors to access the database within separate contexts. However, the meme for the computer program may also be a resource with respect to the human user with settings that for example, prevent the human from making modifications to the program.
Resources are any memes that need to be secured. Links do not have their own security but instead inherit their security from memes that represent them. There are currently three security operations defined on all memes (and via inheritance, on links as well). The most basic operation is “read”, which allows or disallows an actor to read the resource (or know of its existence). The second operation is the “link” operation which specifies whether the actor is allowed to create links based on the resource. Finally, the “write” operation governs access to the meme itself (such as modifying its name or aliases, file-data or metadata or other security settings).
The structure of the actual security model is explained next. All actors have a list of capabilities for each operation (read, link and write). These capabilities are basically ‘keys’ using which the actor can access the resource in a way that enables them to perform the relevant operation. For example the capability for a user might be: {‘read’:memeA, memeB, memeC, ‘write’:memeC, ‘link’:memeB, memeC} wherein the entities memeA, memeB, and memeC are simply the UUIDs of the respective memes. Alternatively, the entities are represented by specialized keys that point to the relevant UUIDs. The system restricts or prohibits illegal modification of resources outside secure contexts.
In order to provide simple maintenance along with the powerful capabilities, a second tier—called the policies layer—is provided in the database. Policies are business rules that guide the security engine of the database in the absence of specific capabilities. Hence, capabilities need only be used in the exceptional case. Most security settings can be managed by simply creating a few blanket policies.
Resources have policies. Each operation (that is, read, write, and link) of a resource has a policy defined for it. Unlike in the case of capabilities, the policies are not a list. Policy for a resource, r, is a set of functions f read (a), f link (a), f write (a),where the argument ‘a’ of the respective functions ‘f’ is an arbitrary actor. A function returns a value True or False, which dictates whether the actor a has access to the resource r for the given operation; the value True allowing the access and the value False denying it. The database of the present system also allows formation of a chain of functions together to form a cumulative function.
The order of priority is such that capabilities are checked first. If the capabilities of an actor fail to grant access, only then policies are checked. If capabilities clear the security barrier, the policy definition is redundant (capabilities supersede policies).
Processing the security is described in the flowchart outlined in FIG. 6 . Simply speaking, capabilities trump policies. To access a resource, an actor must either possess the capability for the relevant operation for the resource or be granted access by the policy for the resource. Either will do. An actor will be denied access to a resource if and only if it does not possess the capability and if the resource policy denies access as well. A key point to be noted is that possessing the capability is sufficient for gaining access, even if the policy denies access. This mechanism can be used to implement exceptions to a policy.
Based on the foregoing discussion, some of the advantages and unique features of the database are:
Add data without defining its structure beforehand Ability to access data based on a limited class definition which enables applications to take a myopic view of data. Instances of ‘null data’ can be handled without system overheads Extend individual ‘records’ without having to redefine classes Since properties are not stuck inside classes, OLAP queries are possible without having to visit the entire class. No need for Ids and Primary Keys (automatically handled by UUIDs)
Summary of Advantages
The database is designed to serve as a universal repository for data. Since the relationships are tracked between atomic data units, it is possible to slice the universe across any dimension. Hence, multiple diverse applications may be served by providing different slices of data. Moreover, the client application need not know of the scope of data within the database. Instead, it is able to specify a class definition (much like a template) for the result-set. Since the authors need not agree with the consumers, the database is a perfect solution for fragmented environments with multiple players.
Operationally, the database reduces the costs of development by reducing the need for communication, negotiation and agreement (which typically implies a heavy overhead) between different parties involved in a project.
Moreover, the database is architected with a view towards backwards compatibility. Importing data from any relational database into the database described here is a single step process (each row in a table is an object instance which can be persisted) and can use the existing access methods of the relational database.
Exporting data from the database described here back into a relational database is possible. However the complexity of the data implies that any relationships not supported by the target schema will be lost.
EXAMPLE 1
The navigation of data is best illustrated with an example that follows.
Consider again the example from the ontology section where we represented that John lives in New York City using the database described above. We created the database by creating relevant neurons. John and New York City are the minimum memes that we needed to create. In addition, the concept of living somewhere was represented as yet another Meme. This was done by creating another meme which was simply be called “lives in” or as the attribute name “city” which is yet a third meme.
The database assigned for each neuron a UUID which was used to uniquely identify it. As shown in FIG. 4 , the words “John”, “city” and “New York City” are simply aliases which point to the relevant WUIDs as represented by Index 1 .
We required a fourth neuron which would be the Link (l) which binds the various memes together. Hence, a Link was created whose subject was the meme “John”, verb was the meme “lives in” or “city”, and object was the meme “New York City”.
Hence the relationships were represented as subject
S(l)=Meme “John”;
verb V(l)=Meme “city” or the meme “lives in”, and
the object O(l)=meme “New York City”.
In addition,
LS(Meme “John”)=set(l),
LV(Meme “city”)=set(l),
LO(Meme “New York City”)=set(l)
Suppose now we wished to find from our database everyone who lived in the city of the New York City. The query for this took the form of:
(*, ‘city’, ‘New York City’), or (*, ‘lives in’, ‘New York City’).
In plain English, the query for the query engine could be restated as: ‘find all links where the verb is meme “city” (or the meme “lives in”), and the object is the meme “New York City”’.
The query processor executed the following steps in response to the query.
Step 1 : Using Index 1 , find all UUIDs corresponding to “city” and “New York”. Step 2 : Using Index 2 , find the neurons for the respective UUIDs. Step 3 : For each neuron for “city”, find its set LV and take the union of all such sets. This returns the UUIDs of all links in which the verb is a neuron with alias “city” complying with the condition that the UUID of Link l must be an element in this set. Step 4 : For each neuron for “New York City”, find its set LO and take the union of all such sets. This returns the ids of all links in which the object is a neuron with alias “New York City”. The id of Link l must be an element in this set. Step 5 : Intersect the union sets from Step 4 and Step 5 . This returns the UUIDs of all links with verb “city” and object “New York City”. Use Index 2 again to retrieve the neurons. The Link l must be an element in this set. This is our result.
Next, suppose we request to specifically return the ‘names’ of persons living in New York City. We do this using the following query:
subjects(*, ‘lives in’, ‘New York City’)
The arguments of the query are the same as before, except instead of returning the entire link, we are now only requesting for the subjects of each of these links. In this case, after Step 5 , we add another step.
Step 6 : For each neuron in the intersected set of Step 5 (which must contain *all* links meeting our query, since we have intersected LV and LO), retrieve its subject S. This is the result of our query.
Suppose we wished to find from our database the ZIP Code of each person living in New York. One way to represent the query would be:
objects(subjects(*, ‘city’, ‘New York City’), ‘Zip Code’, *)
Restated, this means: ‘find all Memes which participate as the subject in a link where the verb is “city” and the object is “New York City”; For each such meme, find the objects of links where the subject is one of these memes and the verb is “Zip Code”’.
This also illustrates how queries can be nested and the result of one query can be used as the input term for another query.
In order to execute the nested query, we executed all the six steps listed previously. Thereafter, we executed Step 1 afresh, calling it Step 7 for our example, followed by other steps as listed below.
Step 7 : Using Index 1 , find all WUIDs for the alias “Zip Code” Step 8 : Using Index 2 , find all neurons for the UUIDs found in Step 7 . Step 9 : For each neuron for “Zip Code”, find its set LV and take the union of each such set. This returns the ids of all links in which the verb is a neuron with alias “Zip Code”. Step 10 : Intersect this set with the result set from Step 6 . Use index 2 again to retrieve the neurons. Step 11 : Find the object O for each neuron in Step 10 . This is our result.
While the above description contains many specific details, these should not be construed as limitations, but rather as an exemplification of preferred embodiments. Many other variations are possible. In particular, references to aspects of “the database” should not be deemed to define mandatory components unless explicitly stated by the following claims. | A non-relational transactional and analytical database is described. It has a novel data architecture that allows data to persist without requiring any schema definition. The database also provides a file system with in-built versioning, reliability and security and can be deployed in a distributed environment. The approach adopted is to break down data into its fundamental atomic components, called memes, and use a special type of graph (utilizing non-standard vertices and edges) to create logical relationships, represented by links, between these components. The database operational functionality is deployed through an application program interface (API). The underlying query language is based on recursive triplets of the form (subject, verb, object) and can be easily augmented with different query parsers, which translate from some source syntax to this syntax. The memes and links may be identified with Universally Unique Identifiers (UUIDs). Additionally, the database may provide file system manipulation functionality through the use of UUIDs. | 6 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to the field of memories and more specifically of ROMs.
2. Discussion of the Related Art
Conventionally, in a ROM, storage elements or memory points are arranged at the intersection of rows and columns, each memory point being likely to memorize a binary state, that is, a 0 or a 1. Thus, each memory point is a single-bit point.
To reduce the size of memories, it has been provided that each memory point, instead of being able to be in one or the other of two states, is likely to provide a richer information, characteristic for example of one or the other of three or four states. Preferably, for memory management reasons, it would be preferred for each memory point to be able to memorize an integral number of bits, that is, a number of data equal to an integral power of 2. Each memory point would for example correspond to a transistor, the conduction level of which would be greater or smaller when controlled to be in the on state. For this purpose, it may be envisaged to provide, at the level of each memory point, transistors of larger or smaller size, or again to provide transistors with a floating gate, the gate of which is more or less precharged. However, none of these solutions has been crowned with industrial success in standard CMOS technology, most likely because all these solutions imply relatively complex technological operations and require comparing a voltage or current level with several distinct thresholds. This operation is always relatively complex and risks suffering from a lack of reliability if the component characteristics drift.
SUMMARY OF THE INVENTION
Thus, an object of the present invention is to enable storage in a simple memory point of several data, that is, an information of several bits, or multibit information.
Another object of the present invention is to provide an array of such memory points in which the memory points are all identical.
Another object of the present invention is to provide such a memory point array in which the read operations are binary and reliable.
Another object of the present invention is to provide such a memory point array which is particularly easy to form and which takes up little room on an integrated circuit.
To achieve these objects, the present invention provides a ROM including a set of memory points arranged in rows and columns, in which each memory point, formed of a single controllable switch, memorizes an N-bit information, with N>=2. Each column includes 2N conductive lines; each of the two main terminals of each memory point is connected to one of said conductive lines, each information value being associated with a specific assembly of 2 N connections from among the set of 2 2N possible connections; and each of N read means is provided to apply a precharge voltage to a chosen group of 2 N first lines, connect the 2 N other lines to a reference voltage, select a memory point, read the voltages from the first lines, combine the obtained results to provide an indication of the value of one of the bits of the information contained in the selected memory point.
According to an embodiment of the present invention, each switch is a MOS transistor, two adjacent transistors of a same column having a common source/drain region.
According to an embodiment of the present invention, the gates of the MOS transistors of a same row are interconnected.
The foregoing objects, features and advantages of the present invention, will be discussed in detail in the following non-limiting description of specific embodiments in connection with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a column of memory points of the connection position coding type;
FIG. 2 shows an embodiment of a two-bit memory point column according to the present invention;
FIGS. 3A and 3B show read circuits adapted to the memory column of FIG. 2;
FIG. 4 shows an embodiment of a set of two-bit memory point columns according to the present invention;
FIG. 5 shows an embodiment of a three-bit memory point column according to the present invention;
FIGS. 6A, 6 B and 6 C show read circuits adapted to the memory column of FIG. 5; and
FIG. 7 shows an embodiment of a set of three-bit memory columns according to the present invention.
DETAILED DESCRIPTION
One of the bases of the present invention has been for the inventor to consider and classify the various types of existing memory cells to search whether one of the cells could be transformed into a multibit cell.
The most current memory cells are cells in which, at a crossing point, a memorized information materializes as the presence or the absence of a transistor, or more generally as the presence of an active or inactive transistor. An active transistor is a transistor which turns on when a signal is applied to its control terminal, generally, its gate, since memories are generally designed based on MOS transistors. An inactive transistor is a transistor which remains off while the signal applied on its gate is enough to turn on a corresponding active transistor. Such an inactive transistor is generally made like an active transistor, by skipping or adding one or several manufacturing steps so that it is not functional. It can be said that such conventional memories are memories with a coding by the presence or the absence of a transistor.
A second type of memory point has been described in U.S. Pat. No. 5,917,224 of L. Zangara, sold to the applicant. The architecture of a memory point column of this second type is shown in FIG. 1 . This column includes a chain of transistors T, two adjacent transistors having confounded source-drain regions. To each column are associated two lines A and B between which, in the reading, it is attempted to determine whether there is or not a conduction. Generally, one of these lines is assigned to a reference voltage, the other line is precharged, and, after the end of the precharge, the potential difference between the two lines is read while one of memory points T is addressed All the memory points are identical active transistors but each transistor has its main terminals connected either to the same line or to two different lines. If both terminals are connected to the same line and this transistor is addressed, the precharged line will remain at the precharge voltage, which characterizes a first state. If the two terminals of the addressed transistor are connected to different lines, this transistor short-circuits the two lines and the voltage of the precharged line drops, which characterizes a second state. It can be said that this second type of memory is a connection position coding memory.
The present invention provides a modification of this second type of memory to make it a multibit memory. The present invention will first be described in the case where a memory point enables storing a three-bit information, which will result in a generalization of the present invention.
Two-bit Memory Point
FIG. 2 illustrates an embodiment of a two-bit memory point memory according to an embodiment of the present invention. Each column of the memory includes a chain of transistors T 1 associated with four (2 2 ) lines A, B, C, D. Each column is associated with a read circuit such as illustrated in FIGS. 3A and 3B. For two adjacent transistors of a same column, the drain of one transistor corresponds to the source of the other. Each transistor has its drain connected to one of lines A, B, C, D and its source connected to one of lines A, B, C, D (possibly the same line). All transistors are identical and are active transistors
In read mode, one of the column transistors is selected and the read circuit is successively placed in the configuration illustrated in FIG. 3A, then in the configuration illustrated in FIG. 3 B. This switching from one configuration to the other may be performed by any known switching means. Read circuits associated with storage means could also be simultaneously used.
In the configuration of FIG. 3A, two of the lines, A and C, are connected to a reference voltage, which will be called the ground for simplification, but which must only be different from a precharge voltage mentioned hereafter. The other two lines, B and D, are likely to be precharged, then connected to an AND gate 10 , via respective read amplifiers A 1 and A 2 . Thus, if the column transistor that receives a control signal has its terminals connected to the same line, to line B and to line D or to line A and to line C, this transistor will connect none of lines B and D to ground. These lines will remain at the precharge voltage, both amplifiers A 1 and A 2 will provide a signal in the high state (1), and the AND gate 10 will output a 1. However, if the considered transistor connects line B or line D to line A or to line C, a 0 will be detected. This corresponds to the reading of a first bit of the considered memory point.
In a second read phase, to read the second bit, the modified read circuit as shown in FIG. 3B, in which lines A and D are grounded, and lines B and C are likely to be precharged, then “read”, may be used. It the considered transistor T 1 has its main terminals connected to the same line, to lines A and D or to lines B and C, lines B and C will not be discharged. However, if the considered transistor has one of its terminals connected to line B or C and the other one of its terminals connected to line A or D, line B or C will discharge. In the first case, a 1 will be detected at the output of AND gate 10 , and in the second case, a 0 will be detected.
Based on these considerations, and considering the specific read circuits illustrated in FIGS. 3A and 3B, it can be seen that for each memory point, data 00, 01, 10, and 11 may be coded in one of the four ways indicated in the following table 1.
TABLE 1
Data
Drain/source connections of the MOS transistor
00
AB
BA
CD
DC
01
AD
BC
CB
DA
10
AC
BD
CA
DB
11
AA
BB
CC
DD
For the completeness of the table, it has for example been indicated that datum 00 could be created by connection AB or BA and by connection CD or DC. These are in fact symmetrical connections.
It should be noted, comparing this table with the read circuits of FIGS. 3A and 3B, that these circuits effectively decode the indicated two-bit data for the indicated connections. As an example, the coding corresponding to each of the column transistors, successively 10, 01, 10, 00, 11, 10 and 00 for the read mode illustrated in FIGS. 3A and 3B, has been indicated in FIG. 2 .
Generally, from the time that a mode for reading the two bits has been chosen, by assigning a reference line (here, line A) then by first “reading” two of lines B, C, D (here, lines B and D), then reading two other lines out of B, C, D (here, lines B and C), a transistor coding table can be constructed. It is important that, for each transistor, a connection to any one of the lines and to another chosen line can be provided to perform any chosen coding given that two adjacent transistors have a common terminal and thus that, once a transistor has been programmed, the connection of one of the terminals of the immediately adjacent transistor is predetermined.
Since one of lines A, B, C and D, here line A, always is at the reference voltage, two adjacent columns can share a common line. This is shown in FIG. 4 in which seven successive rows i+3 to i−3 and four successive columns j−1 to j+2 have been illustrated. Column j−1 includes four lines D j−1 , C j−1, B j−1 , and A j−1 and column j includes four successive lines A j , B j , C j , and D j . Lines A j−1 and A j form one and the same line. Similarly, for columns j+1 and j+2, line A j+1 and line A j+2 are one.
Various alterations and modifications will occur to those skilled in the art. Each memory point has been illustrated in the drawing as being a MOS transistor. Generally, it may be any structure forming a controllable switch and the various types of controllable switches known in the art may be used.
An important advantage of the present invention is the fact that each memorized bit couple is detected by two successive binary state read operations. Upon each reading, a high or low level is detected, rather than various intermediary levels.
Three-bit Memory Point
FIG. 5 illustrates a column of a memory according to the present invention in which each memory point is likely to memorize three data bits. Each column includes a chain of transistors T 2 associated with eight (2 3 ) lines A, B, C, D, E, F, G, H. Each transistor has its drain connected to one of lines A, B, C, D, E, F, G, H and its source connected to one of lines A, B, C, D, E, F, G, H (possibly the same).
The reading of such a memory point is performed by successively using read circuits such as illustrated in FIGS. 6A, 6 B, and 6 C. In each read circuit, four lines are grounded and four lines are prechargeable and connected to read amplifiers A 11 , A 12 , A 13 , and A 14 having their outputs connected to an AND gate 20 . The read circuits can be distinguished in that in each circuit, four lines different from those of the preceding circuit are connected to the read amplifiers. In practice, this can be achieved by appropriate switching circuits. These read circuits are successively used to read the first, second, and third bits memorized in each memory point. It should be understood, by analogy with the two-bit circuit, that:
for the circuit for reading the first bit shown in FIG. 6A, the output will be at 1 if the terminals of the considered memory point are connected between lines A, C, E and G or between lines B, D, F et H or to the same line; and the output will be at 0 if the connections of the involved memory point are arranged between any one of lines B, D, F and H and any one of lines A, C, E and G;
for the circuit for reading the second bit shown in FIG. 6B, the output will be at 1 if the considered memory point has its terminals connected between one of lines A, D, E, or H or between one of lines B, C, F or G or to two lines or to the same line; and the output will be at 0 if the connections of the involved memory point are arranged between any one of lines B, C, F, and G and any one of lines A, D, E and H; and
for the circuit for reading the third bit shown in FIG. 6C, the output will be at 1 if the memory point has its terminals connected between lines A, B, G or H or between lines C, D, E or F or to the same line; and the output will be at 0 if the memory point is connected between one of lines C, D, E, F and one of lines A, B, G or H.
This corresponds to the following table 2.
TABLE 2
Data
Drain/source connections of the MOS transistor
000
AF
BE
CH
DG
EB
FA
GD
HC
001
AB
BA
CD
DC
EF
FE
GH
HG
010
AD
BC
CB
DA
EH
FG
GF
HE
011
AH
BG
CF
DE
ED
FC
GB
HA
100
AC
BD
CA
DB
EG
FH
GE
HF
101
AG
BH
CE
DF
EC
FD
GA
HB
110
AE
BF
CG
DH
EA
FB
GC
HD
111
AA
BB
CC
DD
EE
FF
GG
HH
It should be noted that, in the read circuits of the three-bit cell, as for the two-bit cell, a line (line A) is constantly grounded. This line may be common to two neighboring cell columns. This is shown in FIG. 7 where it can be seen that among lines A to H of columns j−1 and j, lines A j and A j−1 form one and the same line.
Multi-bit Memory Point
What has been described previously generalizes to N-bit memory points. For this purpose, each column will include 2 N lines and the memory points will have their terminals connected to one of these 2 N lines. N read circuits will be provided, selectively connected to 2 N−1 different lines among the 2 N lines. Based on these connections, those skilled in the art will readily determine a coding table corresponding to above tables 1 and 2.
The present invention is likely to have various alterations, modifications, and improvement which will readily occur to those skilled in the art. Especially, according to the choices made for the read cell connections, a corresponding table enabling identification of N bits per memory point associated with 2 N lines may each time be deduced.
In a practical embodiment, those skilled in the art will be able to manufacture the illustrated circuit in various manners, for example, by providing the various lines forming each column in various metallization levels and by providing connections (vias) between the various metallization levels. Each transistor has been indicated to be connected to a column formed of several lines. Terms “column” and “row” are interchangeable, “column” not necessarily implying that the corresponding lines are vertical.
Although each memory point has been described as being a MOS transistor with its drain or source region common to the source or drain region of the adjacent MOS transistor of the same column, any switchable switch may be used.
Such alterations, modifications, and improvements are intended to be part of this disclosure, and are intended to be within the spirit and the scope of the present invention. Accordingly, the foregoing description is by way of example only and is not intended to be limiting. The present invention is limited only as defined in the following claims and the equivalents thereto. | A ROM including a set of memory points arranged in rows and columns, in which each memory point, formed of a single controllable switch, memorizes an N-bit information, with N>=2. Each column includes 2N conductive lines; each of the two main terminals of each memory point is connected to one of said conductive lines, each information value being associated with a specific assembly of 2 N connections from among the set of 2 2N possible connections; and each of N read means is provided to apply a precharge voltage to a chosen group of 2 N−1 first lines, connect the 2 N−1 other lines to a reference voltage, select a memory point, read the voltages from the first lines, combine the obtained results to provide an indication of the value of one of the bits of the information contained in the selected memory point. | 6 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention is related to an external door apparatus constructed to provide an integrated mechanism for a visitor to acknowledge her presence, an occupant to visually identify the visitor without opening the exterior door, and a support for a decorative object.
[0003] 2. Discussion of the Background
[0004] Many homeowners enhance the purpose and aesthetics of their external doors for safety, visitor acknowledgement, and decoration. Conventional peepholes are installed for the purpose of the occupant to identify the visitor without opening the door. Door knockers are installed to enhance the beauty of the home and to enable the visitor to acknowledge their presence. In addition, many occupants decorate their external doors with wreaths, door swags, and the like to enhance the beauty of the home. These safety and decorative accessories are purchased and installed individually.
[0005] As recognized by the present inventor, it is common for these objects to be misaligned during installation, leaving a less than desirable effect. Removable wreath hangers are unstable and often scratch the exterior door. Furthermore, they are usually used during only part of the year, and removing it from the door during off-seasons leaves the owner to repair the damage.
SUMMARY OF THE INVENTION
[0006] One purpose of this invention is to provide a combination peephole, door knocker, and decoration hanging device that allows enough room for the decorative object to hang unobtrusively to either the peephole or door knocker.
[0007] One object of the present invention is to overcome the difficulties and limitations of conventional approaches to installing individual peepholes, door knockers, and door decoration support hangers.
[0008] A feature of the present invention is a combination peephole, door knocker, and door decoration support hanger for installation as a single unit. The combination peephole, door knocker, and door decoration support hanger has a main body of a predetermined width, a predetermined length that extends from a top to a bottom, a predetermined thickness, a front surface, and a back surface.
[0009] In one embodiment, the front surface is made up of two contiguous surface portions, which are attached together by a hinge. A first surface portion is oriented above a second surface portion. The first surface portion is configured to support a door decoration support, a peephole, a strike plate, and a stationary top hinge portion. The door decoration support is oriented above the peephole such that when the door decoration support is in use, the door decoration does not obstruct the view from the peephole. The second surface portion is configured to support a non-stationary bottom hinge portion and a door knocker. The first surface portion and the second surface portion are formed as an integral unit.
[0010] The back surface is configured to attach the combination peephole, door knocker, door decoration support hanger to the door.
[0011] In another embodiment, the door decoration support is a recessed area oriented along the top of the back surface following the contour of the combination peephole, and door decoration support hanger.
[0012] In a further embodiment, the door decoration support is at least one hook oriented along the top of the back surface following the contour of the combination peephole, and door decoration support hanger.
[0013] In yet another embodiment, the door decoration support is at least one adjustable tab, oriented along the top of the back surface following the contour of the combination peephole, door knocker, and door decoration support hanger.
[0014] In still a further embodiment, the door decoration support is a malleable material oriented along the top of the back surface following the contour of the combination peephole, door knocker, and door decoration support hanger.
[0015] Another feature of the combination peephole, door knocker, and door decoration support hanger is an engraveable area on the first surface portion.
[0016] In another embodiment only a peephole and door decoration support hanger are combined.
[0017] In another further embodiment, the knocker is detachably attached from the peephole and door decoration support hanger.
[0018] In a further embodiment, the engraveable area is optional.
[0019] The present inventor recognized that there is competition for the space at the center, eye-level portion of a front-door. Although many doors include a centered peep-hole with a door knocker close by, these devices are usually rendered unfit for their intended purpose when the homeowner installs a wreath. Moving the peephole, or door knocker is not practical, and so it is often the case that the function of these devices is compromised when a wreath-hanger and wreath are installed and displayed on the exterior door.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] A more complete appreciation of the invention and many of the attendant advantages thereof will be readily obtained as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings, wherein:
[0021] FIG. 1 is a front view of a combination peephole, door knocker, and door decoration support hanger according to the present invention;
[0022] FIG. 2 is a side view of the combination peephole, door knocker, and door decoration support hanger of FIG. 1 ;
[0023] FIG. 3 is a back view of a combination peephole, door knocker, and door decoration support hanger according to FIG. 1 ;
[0024] FIG. 4 is a cross section view of the recessed decoration hanger according to the present invention;
[0025] FIG. 5 is a cross section view of the keyed slot decoration hanger embodiment of the present invention;
[0026] FIG. 6 is a side view of a slidable hook;
[0027] FIG. 7 is a back view of the at least one hook decoration hanger embodiment of the present invention;
[0028] FIG. 8 is a cross section view of the at least one adjustable tab decoration hanger embodiment; and
[0029] FIG. 9 is a front view of a combination peephole and door decoration support hanger noting that the door knocker, non-stationary hinge, and strike plate may be removably attached.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0030] Referring now to the drawings, wherein like reference numerals designate identical or corresponding parts throughout the several views, and more particularly to FIG. 1 , FIG. 1 shows a first embodiment of a combination peephole, door knocker, and door decoration support hanger according to the present invention. A main body 1 has a predetermined length, L, in an inclusive range of five to nine inches, a width, W, in an inclusive range of five inches to nine inches, and a thickness, T ( FIG. 2 ), in an inclusive range of one half inches to three inches along the length direction. While specific ranges are given, the invention should not be construed as being restricted to these dimensions, within the spirit and scope of the invention. The L, W, and T dimensions may vary according to the door size. For example, a small size (and thus smaller dimensions) is more appropriate for apartment doors, while larger sizes are more appropriate for larger scaled doors of large estate homes. The main body 1 and associated components are optionally constructed of molded plastic, metal (e.g., brass, chrome, steel, or the like), or hybrid parts. These parts are either integrally formed, or assembled, such as with screws or adhesive, as subcomponents.
[0031] The main body 1 has a front surface 2 that includes a first surface portion 3 to support a stationary portion of the combination peephole, door knocker, door decoration support hanger, and a second surface portion 4 to support a non-stationary portion of the combination peephole, door knocker, and door decoration support hanger. The first surface portion 3 supports a door decoration support 5 , a peephole 6 , a strike plate 7 , and a stationary top hinge portion 8 . The door decoration support 5 is a recessed area oriented along an outside contour of the first surface portion 3 . The door decoration support 5 could also be made from hooks, adjustable tabs, or a malleable material that is able to support a decorative object. The door decoration support 5 is configured to enable the decorative object to be displayed without obstructing the view from the peephole. The second surface portion 4 supports a non-stationary bottom hinge portion 9 and a door knocker 10 . When used, the door knocker 10 is rotated about the hinge and then brought into contact with the door or an optional strike plate 7 to make an audible noise.
[0032] FIG. 2 is a side view of the combination peephole, door knocker, and door decoration support hanger shown in FIG. 1 . In this embodiment the main body 1 is made of a molded stainless steel. However, the main body 1 could also be made from a molded aluminum, brass or other material that is able to support a door decoration. The main body 1 has a thickness, T, in an inclusive range of one half inches to three inches along the length, L, direction. The door decoration support 5 is a recessed area oriented along an outside contour of the first surface portion 3 . The door decoration support 5 could also be a least one hook, or at least one adjustable tab, or a malleable material oriented along an outside contour of the first surface portion 3 that is able to support a door decoration. The peephole 6 provides an unobstructed view.
[0033] FIG. 3 shows a back view of a combination peephole, door knocker, and door decoration support hanger according to the present invention. The first surface portion 3 provides a primary attachment area 30 oriented above the peephole 6 and a secondary attachment area 31 oriented below the peephole 6 . The combination peephole, door knocker, and door decoration support hanger is attached to a door using screws. The glass for the peephole 6 is optionally integrated into the structure, or it is installed separately and the structure includes a through bore that is aligned with the peephole and provides an unobstructed view through the peephole.
[0034] FIG. 4 shows the door decoration support hanger as a recessed area 41 . The recessed area 41 is formed in the first surface portion 3 of FIG. 1 . The door decoration rests upon this recessed area 41 .
[0035] FIG. 5 shows the door decoration support hanger as a keyed slot. The keyed slot door decoration support hanger 5 is formed in the first surface portion 3 that receives one or more slidable hooks 52 that are removably slid in the keyed slot 51 when support is needed for the decorative object. In FIG. 1 , the keyed slot is shown in dashed lines. The slot has a keyed opening 51 , such as in a dovetail shape. A hook 52 to be installed has a shape at an end opposite to the hook, where this end has a cross-section made to be received in the keyed opening. When installed, the hook 52 cannot be removed from the front because the keyed-end of the hook 53 as shown in FIG. 6 is held by the slot.
[0036] FIG. 6 shows a side view of the slidable hook 52 that is inserted into the keyed opening 51 of FIG. 5 . The slidable hook 52 has a shape at an end opposite to the hook 53 , where this end has a cross-section made to be received in the keyed opening 51 of FIG. 5 . When installed, the hook 52 cannot be removed from the front because the keyed-end of the hook 53 is held by the slot 51 of FIG. 5 .
[0037] FIG. 7 shows a back view of the first surface portion 3 wherein the door decoration support hanger 5 being at least one hook 61 on an outer perimeter 62 of the primary attachment area 3 of FIG. 3 .
[0038] FIG. 8 shows a side view of the door decoration support hanger 5 being at least one adjustable tab 71 on an outer perimeter of the primary attachment area 3 of FIG. 3 .
[0039] FIG. 9 shows another embodiment of a combination peephole and door decoration support hanger with the door knocker 90 and strike plate as optional attachments. A main body 80 has a predetermined length, L, in an inclusive range of five to nine inches, a width, W, in an inclusive range of five inches to nine inches, and a thickness in an inclusive range of one half inches to three inches along the length direction. While specific ranges are given, the invention should not be construed as being restricted to these dimensions, within the spirit and scope of the invention. The L, W, and T dimensions may vary according to the door size. For example, a small size (and thus smaller dimensions) is more appropriate for apartment doors, while larger sizes are more appropriate for larger scaled doors of large estate homes. The main body 80 and associated components are optionally constructed of molded plastic, metal (e.g., brass, chrome, steel, or the like), or hybrid parts. These parts are either integrally formed, or assembled, such as with screws or adhesive, as subcomponents.
[0040] The main body 80 has a front surface 82 that includes a first surface portion 83 to support a stationary portion of the combination peephole and door decoration support hanger with the door knocker and strike plate as optional attachments, and an optional second surface portion 84 to support a non-stationary portion of the combination peephole and door decoration support hanger with the door knocker and strike plate as optional attachments. The first surface portion 83 supports door decoration support 85 , a peephole 86 , and a stationary top hinge portion 88 . While the first surface portion 83 is shown having a semi-circular shape, the invention should not be construed as being restricted to this shape. The door decoration support 85 is a recessed area oriented along an outside contour of the first surface portion 83 . The door decoration support 85 could also be made from hooks, adjustable tabs, or a malleable material that is able to support a decorative object. The door decoration support 85 is configured to enable the decorative object to be displayed without obstructing the view from the peephole. The optional second surface portion 84 supports a non-stationary bottom hinge portion 89 , a removably attached door knocker 90 , and a removably attached strike plate 87 . When used, the removably attached door knocker 90 is rotated about the hinge, then brought into contact with the removably attached strike plate 87 to make an audible noise. | An integrated peephole, door knocker, and door decoration support hanger constructed as an integral unit to aid in a single installation and preservation of an outward facing door. | 4 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The invention relates to a hydrodynamic clutch arrangement which is used to establish and to release a working connection between a drive and a takeoff.
[0003] 2. Description of the Related Art
[0004] A hydrodynamic clutch arrangement of this type, which is known from FIG. 5 of DE 103 58 902 A1, is used to establish and to release a working connection between a drive, such as the crankshaft of an internal combustion engine, and a takeoff, such as a gearbox input shaft, and is designed with a housing, which is free to rotate around an axis of rotation. In DE 103 58 902 A1, the clutch arrangement is designed as a hydrodynamic torque converter, in which a hydrodynamic circuit is provided with a pump wheel, a turbine wheel, and a stator, which together form a torus volume (TV) enclosed by a torus space. In addition, the hydrodynamic clutch arrangement is provided with a bridging clutch, by means of which the hydrodynamic circuit can be bypassed with respect to the transfer of torque from the drive to the takeoff, where a torsional vibration damper with two sets of circumferential springs is assigned to the bridging clutch to damp torsional vibrations. The bridging clutch and the torsional vibration damper together form a mechanical transmission circuit, which is located inside a clutch space of the housing, where a clutch volume (CV) is determined by this clutch space.
[0005] The hydrodynamic torque converter shown in FIG. 5 of DE 103 58 902 A1 is evidence of a development trend, frequently observed in recent years in hydrodynamic clutch arrangements, according to which the size of the torus space is limited so that the clutch arrangement will fit in a more compact space. There are also trends toward increasing the number of plates in the bridging clutch so that higher torques can be transmitted and toward installing more powerful and therefore more complicated torsional vibration dampers. Because these larger components occupy a considerable amount of room in the clutch arrangement, a larger clutch space is required. FIGS. 1-3 are attached to the present specification to make it easier to understand the explanation of the relevant spaces present in a hydrodynamic clutch arrangement, i.e., the spaces which define the corresponding volumes. FIG. 1 shows the torus volume (TV); FIG. 2 shows the clutch volume (CV); and FIG. 3 shows the resting volume (RV). The resting volume (RV) is present after a minimum resting phase, during which some of the fluid in the hydrodynamic clutch arrangement sinks under the force of gravity into the part of the housing located underneath the axis of rotation, and the rest of the fluid leaves the housing through the flow routes provided.
[0006] When the motor vehicle containing the hydrodynamic clutch arrangement is restarted, centrifugal force begins to distribute the fluid present in the resting volume (RV) throughout the torus volume (TV) and the clutch volume (CV), but at the same time, because the pressure in the torus volume (TV) is positive with respect to that in the clutch volume (CV), at least some of the fluid remaining in the torus volume (TV) is drawn into the clutch volume (CV). This problem is made even worse when the driver shifts the transmission into “Drive” (D), because, as a result, the drive starts to run at a predetermined speed, whereas the takeoff and thus the torsional vibration damper remain essentially at rest. In spite of the applied centrifugal force, this causes fluid to be drawn in the radially inward direction through the torsional vibration damper. If the hydrodynamic clutch arrangement is designed as a two-line system, it is true that, in this operating state, fresh fluid is introduced from a fluid reservoir into the clutch volume (CV) via the opened bridging clutch, but, instead of proceeding initially into the torus volume (TV), this fluid is also drawn radially inward and thus remains in the clutch space. When the vehicle is being started up, these conditions are expressed by the inability of the torus volume (TV), which at this point is still almost completely empty, and of the opened bridging clutch to transmit any significant amount of the torque being introduced by the drive to the takeoff. Only the slip torque of the bridging clutch is able to provide for the transmission of a certain residual torque. It is only as the clutch volume (CV) gradually begins to fill up that fresh fluid begins to be transferred to the torus circuit, and only then does that circuit become filled. A performance characteristic of this type, however, cannot be tolerated in a modern motor vehicle.
SUMMARY OF THE INVENTION
[0007] The invention is based on a task of designing a hydrodynamic clutch arrangement in such a way that, even though the clutch space is larger than the torus space, the torus space can still be filled with fluid at a satisfactory rate, so that, even after the expiration of the minimum resting time, the ability to transmit a sufficient amount of torque is guaranteed when the engine is restarted.
[0008] This task is accomplished by an embodiment of the present invention in which a volume reduction arrangement is introduced into the clutch space of the housing of the hydrodynamic clutch arrangement to reduce the clutch volume (CV). In this way, it is ensured that, after the minimum resting phase subsequent to the operating state, the fluid which has settled under the force of gravity to form a resting volume (RV) underneath the axis of rotation of the housing after the end of the operating state of the drive of a motor vehicle containing the hydrodynamic clutch arrangement, i.e., the fluid which is available for distribution inside the housing by centrifugal force when the drive is restarted, is able not only to fill up the reduced clutch volume (CV) at an accelerated rate but also to fill, at least partially, the torus space as well, thus providing the torus volume (TV) required for the transmission of torque. Thus, when the engine is restarted, sufficient fluid is available promptly in the torus space to ensure a satisfactory transmission of torque from the drive, such as the crankshaft of an internal combustion engine, to a takeoff, such as a gearbox input shaft. This is true even if, as the vehicle is being started up, the driver immediately shifts the transmission into “Drive” (D), which leads to the situation that the pump wheel of the hydrodynamic clutch device starts to turn at the same speed as the drive, whereas the takeoff and thus the torsional vibration damper present in the clutch space are still at rest. In this situation, the volume reduction arrangement will not be able to prevent some fluid from being drawn radially inward inside the clutch space, but because of the significant extent to which the clutch space and possibly the torus space are already filled with fluid, there is no risk that the torus space could be emptied completely.
[0009] As the discussion above has made clear, the torque-transmitting capacity of a hydrodynamic clutch arrangement, such as that of a hydrodynamic torque converter or a hydroclutch at the time of a restart after a certain minimum resting phase, depends on the difference between the resting volume (RV) and the clutch volume (CV). This difference can be described by an evaluation factor (K) which is the ratio RV/CV. As long as this evaluation factor (K), according to the relevant claim, assumes a value of 0.9 or more, preferably a value within a range of 1.0-1.2, an advantageous torque-transmitting ability is obtained even after a restart, because, when the clutch volume (CV) and the resting volume (RV) are related to each other in this way, the latter will always be sufficiently large in comparison to the clutch volume (CV) and as a result will be able to provide at least as much fluid as the clutch space can at least essentially hold, inasmuch as its volume has been decreased by the volume reduction arrangement. Thus, even when the vehicle is being started up and the transmission is shifted into Drive (D), a sufficient amount of fluid will always arrive at the torus space to fill it.
[0010] The volume reduction arrangement can have a single volume reducing element, but it can also have a plurality of these reducing elements. It is especially advantageous for at least some of these reducing elements to be located in the radially outer area of the clutch space, that is, on the radially outer wall of the housing of the hydrodynamic clutch arrangement, so that they can project from there into the clutch space and reduce its volume; that is, they will project into the areas of the clutch space which are not occupied by components of the mechanical transmission circuit such as the bridging clutch and the torsional vibration damper. In this way it is possible, with modest technical effort, to achieve a considerable reduction in the volume of the space. It can be especially preferable for the individual volume reducing element to be designed essentially in the form of a ring. Through appropriate selection of the material for these volume reducing elements, it is also possible to exert an advantageous influence on the inertial behavior of the hydrodynamic clutch device, in the sense that volume reducing elements of heavy material such as metal significantly increase the moment of inertia, whereas volume reducing elements of lighter material such as plastic have only a minor effect. It is also possible simply to lay a volume reducing element in the clutch space, but the element can also be connected to the housing of the clutch arrangement in such a way that it cannot move axially or rotationally.
[0011] Alternatively or in addition, it is also possible to provide at least one volume reducing element of the volume reduction arrangement in a different area of the clutch space; for example, it can be attached to a component assigned to the torus space such as the turbine wheel or the stator. It is also conceivable that a torsional vibration damper installed in the clutch space could be provided with an encapsulation, which would at least essentially prevent fluid from entering the torsional vibration damper. It is also possible to make the capsule space enclosed by the encapsulation considerably larger than the torsional vibration damper. The goal of this measure is to reduce the clutch volume (CV) by an amount equal to the volume of the torsional vibration damper present inside the encapsulation. In this embodiment, the torsional vibration damper would also act as a volume reducing element of the volume reduction arrangement. This is also true even if the encapsulation of the torsional vibration damper is provided with lubrication channels for fluid contained in the clutch space, because the rate at which fluid can enter the capsule space through these lubrication channels is very slow after a restart.
[0012] Although the torus space serves the function of hydrodynamically transmitting torque, an area which is at least essentially unusable in this respect, namely, the internal torus space enclosed by the pump wheel, the turbine wheel, and the stator, is still present inside the torus space. If the clutch space has already been reduced by volume reducing elements of a volume reduction arrangement, it is nevertheless possible, through the use of a volume reducing element in the internal torus space, to achieve an additional reduction of the fluid-holding space inside the housing of the hydrodynamic clutch device. As a result, even if the clutch space cannot hold any volume reducing elements because of the way in which it is designed, it is still possible to improve the torque-transmitting capacity after a restart.
[0013] Other objects and features of the present invention will become apparent from the following detailed description considered in conjunction with the accompanying drawings. It is to be understood, however, that the drawings are designed solely for purposes of illustration and not as a definition of the limits of the invention, for which reference should be made to the appended claims. It should be further understood that the drawings are not necessarily drawn to scale and that, unless otherwise indicated, they are merely intended to conceptually illustrate the structures and procedures described herein.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] In the following, an exemplary embodiment of the invention is presented, where FIGS. 1-3 of the drawing show merely a diagram of the relevant volumes. The inventive volume reduction arrangement is not shown until FIG. 5 :
[0015] FIG. 1 shows a cross section of a hydrodynamic clutch arrangement with a torus space and a clutch space, where the torus volume (TV) determined by the torus space is shaded for emphasis;
[0016] FIG. 2 is similar to FIG. 1 but shows the clutch volume (CV), emphasized by shading, inside the clutch space;
[0017] FIG. 3 is similar to FIG. 1 but shows the resting volume (RV), emphasized by shading;
[0018] FIG. 4 shows a schematic diagram of a drive train with the hydrodynamic clutch arrangement;
[0019] FIG. 5 shows a diagram similar to FIG. 1 , except that volume reducing elements of a volume reduction arrangement have been installed in the clutch space and in the torus space; and
[0020] FIG. 6 shows a diagram of an encapsulation for a torsional vibration damper serving as a volume reducing element of a volume reduction arrangement.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0021] FIG. 4 shows a schematic diagram of a drive train 1 with a hydrodynamic clutch arrangement 3 rotating around an axis 2 . The clutch arrangement 3 comprises a housing 5 , which can be connected for rotation in common to a drive 11 , such as the crankshaft of an internal combustion engine 13 , by means of a plurality of fastening elements 7 and a connecting element 9 such as a flexplate. On the axial side facing away from the drive 11 , the housing 5 has a housing hub 15 , which engages, for example, in a gearbox arrangement 17 and causes a fluid delivery pump there (not shown) to rotate, this pump serving to supply the housing 5 with fluid. A takeoff (not shown) in the form of a gearbox input shaft, the free end of which projects into the housing 5 , is arranged concentrically with respect to the housing hub 15 .
[0022] As FIG. 5 shows in detail, the side of the housing 5 facing away from the drive 11 holds a set of pump vanes 20 and thus forms a pump wheel 22 , whereas a turbine shell 24 holds a set of turbine vanes 26 and thus forms a turbine wheel 28 . A set of stator vanes 32 of a stator 30 is held between the turbine wheel 28 and the pump wheel 22 . The hub 34 of the stator is positioned on a freewheel 36 . This is seated for its own part on the gearbox input shaft serving as the takeoff in the manner known from the previously cited DE 103 58 902 A1.
[0023] In the area over which their vane blading 20 , 26 , 32 extends, the pump wheel 22 , the turbine wheel 28 , and the stator 30 together form a torus space 62 , which at least essentially encloses a torus volume (TV), as emphasized by the shading in FIG. 1 .
[0024] The turbine wheel 28 engages by way of its turbine hub 38 with a torsional vibration damper 40 , which is connected nonrotatably to the radially outer plates 44 of a bridging clutch 45 . Axially between these plates 44 is a radially inner plate 46 , which is connected nonrotatably to a drive-side housing cover 51 of the housing 5 by way of an anti-twist device 50 . A working connection can be established between the plates 44 and 46 for the transmission of a torque from the housing 5 to the takeoff, in that a piston 47 , which is able to shift position axially on a cover hub 49 of the cover 51 , is shifted toward the housing cover 51 , which occurs when the pressure in a hydrodynamic circuit 60 on the side of the piston 47 facing away from the housing cover 51 is greater than that in a pressure chamber 48 , which is located axially between the housing cover 51 and the piston 47 . As soon as the working connection between the plates 44 and 46 and thus also the housing cover 51 has been established by the piston 47 , the bridging clutch 45 is in its engaged position. Conversely, the bridging clutch 45 is moved into its released position when the pressure in the pressure chamber 48 is positive with respect to that in the hydrodynamic circuit 60 .
[0025] The bridging clutch 45 , which forms a mechanical transmission circuit 66 together with the torsional vibration damper 40 , is accommodated together with the torsional vibration damper 40 in a clutch space 64 . This, as can be seen in FIG. 2 on the basis of the shading, encloses a clutch volume (CV).
[0026] It remains to be said about the torsional vibration damper 40 only that it has a torsion damper hub 54 , which serves as a takeoff part 52 and by means of which it is connected nonrotatably by a set of teeth 56 to the takeoff.
[0027] The torus volume (TV) shown in FIG. 1 and the clutch volume (CV) shown in FIG. 2 together form a total volume, through which fluid circulates during the operating state of the clutch arrangement 3 , that is, while the housing 5 is turning around the axis of rotation 2 and the fluid is thus being subjected to centrifugal force. Sufficient fluid is present in the torus space 62 to allow the transmission of even relatively high torques. After the end of this operating state, the housing 5 is no longer rotating, and this allows some of the fluid constituting the total volume to leave the housing 5 through supply channels (not shown) of the clutch arrangement 3 . The rest of the fluid collects in the housing 5 underneath the axis of rotation 2 by the force of gravity. After a certain time at rest, which is referred to below as the “minimum resting phase” and which can easily be in the range of 30-60 hours, the state shown in FIG. 3 is reached, in which all of the fluid still present in the housing 5 has collected underneath the axis of rotation 2 . This fluid-occupied volume is referred to in the following as the “resting volume” (RV).
[0028] As shown in FIG. 5 , two essentially ring-shaped volume reducing elements 70 , 72 of a volume reduction arrangement 68 are supported on the radially outer wall or area of the housing 5 a certain axial distance apart. The drive-side volume reducing element 70 is located essentially axially between the housing cover 51 and the torsional vibration damper 40 , whereas the takeoff-side volume reducing element 72 is located axially between the torsional vibration damper 40 and the turbine wheel 28 and thus the torus space 62 . These volume reducing elements 70 , 72 can be made of metal or of plastic, and they can be merely placed in the clutch space 64 , or they can be permanently connected to the housing 5 by the use of an adhesive, for example, or by riveting or welding.
[0029] Another volume reducing element 74 of the volume reduction arrangement 68 is formed on or attached to the turbine hub 38 of the turbine wheel 28 , whereas another volume reducing element 76 is formed on or attached to the stator hub 34 of the stator 30 . The two last-mentioned volume reducing elements 74 , 76 are thus attached to components 78 and 80 which belong to the torus space 62 and which are able to rotate relative to the housing 5 , the component 78 being formed by the stator 30 , the component 80 by the turbine wheel 28 .
[0030] Another possibility of forming a volume reducing element 84 in the clutch space is shown in FIG. 6 . The torsional vibration damper 40 shown here, which serves as an additional component 82 for accepting a volume reducing element 84 , has seals 86 , 87 in the form of diaphragm-like cover plates on both axial sides. The seal 86 is attached directly to the torsional vibration damper 40 , whereas the seal 87 is attached to the turbine hub 38 of the turbine wheel 28 . The two seals 86 and 87 together form an encapsulation 92 for the torsional vibration damper 40 , where a capsule space 96 enclosed by the encapsulation 92 forms a capsule space volume, by which the clutch volume (CV) of the clutch space 64 is reduced. This capsule space volume can be considerably larger than the minimum volume required to hold the torsional vibration damper 40 , in that, as can be seen in FIG. 6 , the seal 87 is located a certain distance away from the torsional vibration damper 40 . This makes it easy to influence the size of the capsule space volume.
[0031] So that the torsional vibration damper 40 can be operated advantageously, a lubricant supply can be advisable. For this purpose, at least one of the seals 86 , 87 can be provided with lubricant channels 94 ; these channels, however, are dimensioned in such a way that they allow only a small amount of fluid to leak through.
[0032] Another, at least essentially ring-shaped, volume reducing element 88 can be seen in FIG. 5 , but it is not in the clutch space 64 but rather in the torus space 62 . This volume reducing element 88 is located in an internal torus space 90 and thus in an area of the torus space 62 which is not essential to the ability of the clutch arrangement 3 to transmit torque hydrodynamically.
[0033] Regardless of their positioning inside the clutch space 64 , the purpose of the volume reducing elements 70 , 72 , 74 , 76 , and 84 is to bring about a decrease in the clutch volume (CV) in the clutch space 64 and thus to bring the size of the clutch volume (CV) closer to that of the resting volume (RV) reached after the minimum resting phase. This effect, achievable by means of the volume reducing elements 70 , 72 , 74 , 76 , and 84 of the volume reduction arrangement 68 , can be determined or defined by means of an evaluation factor K, which is calculated by means of the following formula:
K =resting volume ( RV )/clutch volume ( CV )
[0034] When the clutch volume (CV) is reduced, the resting volume (RV) is also reduced, but not to the same degree as the clutch volume (CV). The reason for this is that the surface level 98 of the resting volume (RV) (see FIG. 3 ) settles at a value A below the axis of rotation 2 , so that, during this operating state, the fluid-free part of the clutch volume (CV) projects beyond the axis of rotation 2 by the value A. The fluid-free clutch volume (CV) is accordingly larger than the resting volume (RV). As a result of the volume reduction arrangement 68 , therefore, the fluid-free part of the clutch volume (CV) is decreased to a greater extent than the resting volume (RV), and thus the evaluation factor K is increased.
[0035] To ensure that the housing 5 can be filled effectively when the drive 1 and thus the hydrodynamic clutch arrangement 3 are restarted after the minimum resting phase, the evaluation factor K should be above a value of 0.9 and preferably should be within the range of 0.9-1.2. With respect to the number and the dimensions of the individual volume reducing elements 70 , 72 , 74 , 76 , and 84 of the volume reduction arrangement 68 , this means that the clutch volume (CV) inside the clutch space 64 which can be filled with fluid, should be reduced by the volume reduction arrangement 68 in such a way that the resting volume (RV) is only insignificantly smaller than the clutch volume (CV). For example, it can be 0.9 times as large as the clutch volume, but it could also be larger than the clutch volume, such as larger by a factor of 1.2. Between these two extremes is an advantageous design range, according to which the resting volume (RV) will be at least essentially equal to the clutch volume (CV), although it can also be up to 1.2 times larger than the clutch volume (CV).
[0036] The following applies here: If the desired filling behavior of the housing 5 after the minimum resting phase is already achieved with only one volume reducing element 70 , 72 , 74 , 76 or 84 , the volume reduction arrangement 68 needs only this one volume reducing element. If, however, the filling behavior of the housing 5 after the minimum resting phase is still not sufficient with only one volume reducing element 70 , 72 , 74 , 76 , or 84 , the volume reduction arrangement 68 will be designed with at least one additional volume reducing element 70 , 72 , 74 , 76 , or 84 . The effect of the reduction of the clutch volume (CV) of the clutch space 64 brought about by the volume reduction arrangement 68 is as follows:
[0037] If the clutch volume (CV) has been brought to a value at least approximately equal to the resting volume (RV), then, after the minimum rest phase and a restart, it is ensured right from the beginning that the clutch space 64 can be supplied with at least a sufficient amount of fluid. It is also ensured that fluid is also available for the torus space 62 , fluid which can be used for the transmission of torque between the housing 5 and the takeoff. Proceeding from this starting situation in a hydrodynamic clutch arrangement 3 , which is assumed to be designed as a two-line system, additional fluid can be supplied very quickly via the pressure chamber 48 to the hydrodynamic circuit 60 during the further course of operation while the bridging clutch 45 is still open. Because the clutch space 64 is already filled, this additional fluid reaches the torus space 62 very quickly, where it completes the refilling of the torus volume (TV). Thanks to the volume reduction arrangement 68 in the clutch space 64 , a motor vehicle equipped with the inventive hydrodynamic clutch arrangement 3 can be accelerated quickly even when being restarted after the minimum resting phase.
[0038] Thus, while there have shown and described and pointed out fundamental novel features of the invention as applied to a preferred embodiment thereof, it will be understood that various omissions and substitutions and changes in the form and details of the devices illustrated, and in their operation, may be made by those skilled in the art without departing from the spirit of the invention. For example, it is expressly intended that all combinations of those elements and/or method steps which perform substantially the same function in substantially the same way to achieve the same results are within the scope of the invention. Moreover, it should be recognized that structures and/or elements and/or method steps shown and/or described in connection with any disclosed form or embodiment of the invention may be incorporated in any other disclosed or described or suggested form or embodiment as a general matter of design choice. It is the intention, therefore, to be limited only as indicated by the scope of the claims appended hereto. | A hydrodynamic clutch device used to establish and to release a working connection between a drive and a takeoff is disclosed. The device includes a housing capable of rotating around an axis of rotation, the housing containing a torus space, which forms a torus volume (TV) with a pump wheel and a turbine wheel, and a clutch space, which forms the boundaries of the clutch volume (CV) and which encloses a mechanical transmission circuit including a bridging clutch designed with a torsional vibration damper During the course of the minimum resting phase of the housing, the fluid which is distributed throughout the housing during the operating state decreases from a total volume comprising at least the torus volume (TV) and the clutch volume (CV) to a resting volume (RV), which is located at least essentially underneath the axis of rotation as a result of the force of gravity. A volume reduction arrangement is provided to the housing to reduce the clutch volume (CV) versus the resting volume (RV). | 5 |
BACKGROUND OF THE INVENTION
Related Application
This application is a continuation of PCT application No. PCT/FR86/00237 filed July 4, 1986 published as WO87/00232, on Jan. 15, 1987.
The invention relates to a lock comprising a member for controllinq a latch or bolt and a mechanism for actuating this member with the aid of a key bearing a code, via a code identification assembly comprising plates of generally substantially rectangular shape, of the same dimensions, juxtaposed in parallel with a determined pitch and slidably mobile in their longitudinal direction, each of these plates comprising, on a substantially rectilinear longitudinal side, a notch cut at one of several determined locations along this side, the notched sides of all the plates being disposed substantially in the same plane perpendicular to the planes of the plates, so that, into these notches brought into alignment by action of the key on the plates from their rest position, there may come into mesh, by a rectilinear drive edge that it comprises, a member for coupling the plates to the member controlling the bolt, this coupling member being adapted to transmit to said control member the movement imprinted on the key.
The invention has for its object to improve a lock of this type in order to render it particularly difficult to tamper with.
SUMMARY OF THE INVENTION
To this end, according to the invention, the coupling member is a sensing element or feeler which is doubly mobile, parallel to the direction of slide of the plates and substantially perpendicularly to the plane of the notched sides of the plates, this latter mobility affecting at least the drive edge that it comprises, which, being pressed against the assembly of the notched sides of the plates, is capable of engaging in the notches as soon as they are aligned and then of coupling the bolt control member to the plate assembly, with the result that, when introduced into the lock, the key takes along the plates which slide firstly in a stroke of positioning where their notches come into alignment if the key matches the lock, then in a complementary stroke where, if the feeler has been able to come into mesh by its drive edge in the aligned notches of the plates, the latter take along, via the feeler, the bolt control member in the direction of slide of the plates, in a direction tending to place the bolt in position of opening, while a means for returning the bolt control member in opposite direction is provided to return it into position of closure, this means preferably not enabling said member to be moved in the direction of opening.
Stop means should be provided for preventing the feeler from moving in the direction of slide of the plates as long as its drive edge has not come into mesh in the aligned notches of the plates. The feeler thus remains immobilized without being able to take along the member for controlling the bolt until said notches are brought into alignment, which can be obtained only by means of a key bearing the correct coding.
In an advantageous embodiment, the movement of the feeler substantially perpendicularly to the plane of the notched sides of the plates consists in a movement of pivoting about a pivot axis oriented in parallel to this plane and perpendicularly to the direction of slide of the plates, and movable in this direction.
More particularly, the pivot axis of the feeler may be defined by a pair of lateral lugs that it comprises and which are engaged in a pair of slots made in fixed walls of the lock in the direction of slide of the plates, the ends of these slots determining the end positions of the feeler in its displacements in this direction.
The feeler preferably comprises a second pair of lateral lugs located in the vicinity of its drive edge and engaged in a second pair of slots made in said fixed walls, each of these latter slots comprising a first part extending in parallel to the direction of slide of the plates and a second part, relatively short and oriented perpendicularly to this direction, the corresponding lug of the second pair of the feeler being located in this second part when this latter abuts on the plates while they are at rest and their notches are not aligned, this preventing the feeler from moving.
A lock according to the invention does not lend itself to manoeuvres of feeling for the purpose of discovering the coded combination that the plate assembly comprises. In fact, said plates do not oppose the introduction into the lock of a wrong key or any tool: they still slide, but without taking along the feeler. The lock may in addition be provided with an alarm device, adapted to detect and to indicate such manoeuvres, which compares the displacement of the member for controlling the bolt, or of the bolt itself, and that of the plates and is triggered off in the case of non-displacement of said member or of the bolt during the complementary stroke thereof, which is produced as soon as the object introduced into the lock does not effect alignment of the notches of the plates. This alarm device employs, for example, a switch which is fixed to the feeler or to the bolt control member and may be actuated by any one of the plates during said complementary stroke, for example via a transverse bar mobile in parallel to the plane of the notched sides of the plates and perpendicular to the direction of slide thereof, which may move in translation in this direction under the thrust of the plates against an elastic return force; upon withdrawal of the key, said bar further ensures return of the plates into rest position. In the preceding hypothesis of use of a wrong key, in order to avoid the movement of penetration thereof being able to be hindered by untimely catching of the notches of one or of certain of the plates on the drive edge of the feeler in the event of this edge being affected by a slight deformation or a slight offset with respect to its theoretical rest configuration, with the result that the wrong key would not trigger off the alarm device with which the lock is provided, the edge of the notch of each plate by which the drive edge of the feeler is capable of being attacked, should be provided to be joined by a bevel to the longitudinal side of the plate in which the notch is made.
The lock according to the invention is particularly advantageous when it is designed to operate with the aid of a flat key, comprising a front edge provided with cut-outs which show teeth and hollows succeeding one another in a determined coding combination; such a key, introduced into the lock, is capable of selectively pushing, by said front edge, the plates of the identification assembly and of positioning them with their notches aligned, then of causing them to execute their complementary stroke. In a very simple embodiment, the cut-outs of the front edge of the key determine a binary coding, each plate having its notch located in one of two determined locations over its length.
A lock according to the invention may be designed so that the key directly attacks the plates of the identification assembly, in their longitudinal direction of slide. When another direction of introduction of the key is desirable, there may be disposed, upstream of the plates of the identification assembly, an assembly of pivoting bevel gear parts, via which the key may actuate the plates by being introduced into the lock in a direction different from the longitudinal direction of the plates.
According to a feature of the invention, the bevel gear parts, all identical, are mounted freely in juxtaposition on a common transverse pivot pin; each of these parts, associated with a respective plate, is formed by a small plate located in the plane of this plate and comprising a first substantially radial arm, capable of pushing the corresponding plate and of thus actuating it in translation, and a second substantially radial arm, forming an angle with the first arm and capable of being attacked by the key introduced into the lock in said different direction. Two directions of introduction of the key are thus offered, depending on whether the key attacks the bevel gear parts by their first arm (being in that case introduced in the same direction as if it were directly attacking the plates), or by their second arm. These two directions form therebetween an angle which is a function of the angle of the first and second arms of the bevel gear parts. In particular, these arms may be arranged so that the two directions of introduction of the key are substantially perpendicular. In practice, these two directions may correspond respectively to the introduction of the key on the inside and on the outside of the premises defended by the lock.
In order to maintain the bevel gear parts at the pitch of spacing of the plates, which is equal to that of the teeth and hollows of the coded edge of the key, spacer members should be interposed between said parts, which are engaged at at least one point of their periphery in the notches of a transverse part in the form of a rack, the pitch of these notches being equal to the average pitch of the plates of the identification assembly. This latter pitch may itself be defined in similar manner by oblong spacer members, engaged at their ends in the notches of transverse parts in the form of a rack.
The coding notch that each plate comprises on its longitudinal side facing the feeler is advantageously located near its end opposite the one attacked by the key, with the result that the feeler, of which the drive edge is located in the vicinity of the notches of the plates, covers these latter only over a small length. If, in addition, it is provided that the second part of each of the slots of said second pair of slots is continued by a third part, of short length, oriented parallel to the first part, it is possible to cause the feeler to uncover and completely free the plates by placing it provisionally in a position of retraction where it is retained by its second pair of lugs engaged in said third part of the slots mentioned above.
When there is associated with each plate a stop which prevents it from moving in its plane perpendicularly to its longitudinal direction, if this stop is disposed near the end of the plate attacked by the key, it does not oppose the withdrawal of the plate in question, after retraction of the feeler, with a view to changing the code inscribed in the identification assembly of the lock. Such a change may be effected either by exchange of at least one plate with a plate bearing an otherwise positioned notch, or when each plate comprises a coding notch on each of its two longitudinal sides, these two notches having, however, a different positioning, by simple turning of at least one plate in its plane.
The above-mentioned stop, ensuring holding of each plate, may be constituted by a projection of the bevel gear part provided in association with the plate.
Other characteristics and advantages of the invention will be more clearly seen from the following description, with reference to the accompanying drawings, of non-limiting examples.
BRIEF DESCRIPTION OF DRAWINGS
FIG. 1 schematically represents, in perspective, a lock according to the invention, only certain parts of its housing being shown.
FIGS. 2a to 2d represent in longitudinal section the lock of FIG. 1 in different situations of operation.
FIG. 3 schematically shows, in perspective, a variant embodiment of the lock.
FIG. 4 shows a longitudinal section of the lock of FIG. 3 in rest position.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The lock shown in FIG. 1 comprises a housing 1 through which may slide in translation a rectilinear rod 2, under the action of a flat key 3 introduced into the housing through an inlet slot 4, this key acting on the rod 2 via an internal mechanism which will be described hereinafter. One end 2a of the rod 2 constitutes the bolt of the lock, which may be engaged in a combined keeper 5 (FIG. 2a) or be withdrawn therefrom (FIG. 2c). Withdrawal of the bolt 2a from the keeper 5 is effected by introduction of the key 3, while its return into locked position in the keeper 5 is obtained with the aid of an actuation means (not shown), such as a spring or a manual rotating knob bearing an eccentric capable of pushing the rod 2 in the direction of the keeper 5. Of course, the bolt may also be constituted by a piece independent of the rod 2, but coupled thereto so as to be controlled by said rod. An intermediate part may also be provided between the bolt and the rod 2, such as a crank lever, when the direction of actuation of the bolt is different from the direction 6 of translation of the rod 2.
The mechanism of the lock comprises an assembly of oblong plates 7, which are mobile and guided so as to be able to slide longitudinally, in the direction 6 of translation of the rod 2, between small guiding plates 8 juxtaposed parallel to one another with interposition of spacer members 9 slightly thicker than the plates 7. The small plates 8 and the spacer members 9 are assembled on a transverse spindle 30 which traverses them all.
The plates 7 are identical in their general rectangular shape, and each offers a rectilinear side 7a freely flush between the small plates 8 in a common plane parallel to the direction 6. Each of these sides 7a is cut out with a notch 10 of triangular shape, to which is given one of two determined positions over the length of the plate, with the result that the series of notches 10 that the assembly of plates 7 comprises is disposed in accordance with a binary code defined by the respective positions of the successive notches when the plates are in rest position (FIG. 1).
Between the plate assembly 7 and the rod 2 there is mounted a feeler 11 constituted by a piece of sectioned sheet metal adapted to pivot about an axis defined by two lateral lugs 11a engaged in slots 12 which extend in two opposite walls of a chassis 31 inside the housing 1 parallel to the direction 6, and offering, on a border 1c located on the side opposite the said pivot axis, a rectilinear edge 11b applied against the sides 7a with notch 10 of the plates 7 by a low-power leaf spring 13 (FIGS. 2a to 2d). The edge 11b of the feeler 11 is, like its pivot axis, parallel to the plane of the sides 7a of the plates 7 and perpendicular to the direction 6 of displacement of the rod 2 (and of plates 7).
The slot 4 for introduction of the key 3 is located opposite the aligned ends 7b of the juxtaposed plates 7. It extends inside the assembly formed by these plates by a series of slots 14 made in the small guiding plates 8, these slots receiving the key 3 introduced into the lock through the inlet slot 4 and, more precisely, the front edge 3a of the key, which comprises a coding represented by cut-outs showing hollows 15 and teeth 16 which succeed one another in a determined code. The number of binary positions provided on the coded edge 3a is selected so as to obtain a very large number of possible combinations; for example, 32 binary positions provide several billions of different combinations.
When key 3 is introduced into the lock, said key causes each of the plates 7 to move longitudinally in direction 6 by a determined quantity, respectively large or small, depending on whether it is attacked by a tooth 16 or by a hollow 15 of the front edge 3a of the key 3. When the code of the key corresponds to the code of positioning of the notches 10, the latter are brought into alignment and may then receive the rectilinear edge 11b of the feeler 11, which engages under the action of the leaf spring 13 (FIG. 2b).
The key 3 being pushed further into the lock, the plates 7 move all together under the thrust of the key, taking along in their movement of translation the feeler 11 in mesh by its edge 11b with the aligned notches 10. The displacement of the feeler 11 is not hindered by the small guiding plates 8, which comprise large notches 17 of which the length covers the whole stroke made by the notches 10 of the plates 7 at the time of the overall displacement thereof during their complementary stroke following their initial stroke of positioning of their notches.
The rod 2 is coupled in translation to the feeler by a stirrup member 18 which is welded thereon and offers at its ends holes 19 through which pass catches 20 fast with the feeler 11. This mode of coupling to the rod 2 does not hinder the pivoting movements of the feeler.
In this way, when the feeler 11 is driven in translation by the aligned notches 10 of the plates 7, it in turn takes along rod 2 up to an end-of-stroke position (FIG. 2c) where the bolt 2a which terminates it has left the keeper, ensuring the unlocking of the element such as a door on which the lock is mounted. At the same time, the plates 7, or at least those which correspond to teeth 16 of the key 3, repel a wide pivoting blade 21, embracing the whole plate assembly 7, which pivots about a fixed pin 2 perpendicular to the plane of the plates 7, against the force of a return spring 23. It is thanks to this spring that the blade 21 returns the plate assembly 7 into initial rest position (FIG. 2a) upon withdrawal of the key 3, the edge 11b of the feeler then escaping the notches 10 by rising along one of their sides, which, to that end, is given a certain inclination, the other side being perpendicular to the direction 6. It is generally suitable, as shown, that the border 11c bearing edge 11b offers, with respect to the plane of the notched sides 7a of the plates 7, an obliqueness adapted to promote escape of the feeler 11 from the notches 10 in the phase of return to rest of the plates.
When an ill-disposed person seeks to make the lock operate with a wrong key 3', the introduction of this key does not produce the alignment of the notches 10 of the plates 7 (FIG. 2d). However, the wrong key pushes the latter, just like the authentic key 3, but without taking along the feeler 11, which, not having pivoted in the aligned notches, remains retained by stop of a part 24, which it comprises in projection, against a fixed catch 25, fast with the housing 1, with the result that the rod 2 is not actuated.
The fact that the feeler 11 in that case does not accompany the plates 7 in their overall displacement, is detected by a small switch 26 mounted on the feeler and possessing a control lug 26a actuated by a crank arm 27 pivoting about an articulation 28. The end of this arm cooperates with the blade 21, which, on pivoting, may cause it to pivot against the force of a return spring 29 ensuring a permanent pressure on the lug 26a for actuating the switch 26.
When the wrong key 3' is introduced into the lock, the plates 7 cause the blade 21 to pivot, this causing the arm 27 to pivot with respect to the switch 26, moving it away therefrom (FIG. 2d) with the result that the pressure on the lug 26a disappears and the switch 26 operates, indicating in any appropriate manner, by closure of an electric circuit, the illicit attempt to open the lock.
On the other hand, when it is the authentic key 3 which is used, there is no relative movement between the feeler 11 and the plate assembly 7, therefore none between the switch 26 and its actuation arm 27 either (cf. FIGS. 2b and 2c), with the result that the switch does not operate and no alarm is triggered off.
It will be noted that it is possible to modify, if necessary, the code allocated to the lock: it suffices to open the housing and to change the order and/or the type of plates 7 of the identification assembly. Furthermore, the choice of a binary code in the example described is in no way limiting.
The lock shown in FIG. 3 comprises, like the lock of FIG. 1, in a housing 1, an assembly of identification plates 7 in the form of an elongated rectangle, comprising, on their longitudinal side 7a facing the mobile feeler 11, a coding notch 10. Each of the notches may occupy one or the other of two predetermined positions over the length of the side 7a, with the result that the series of notches 10 is disposed in accordance with a binary code peculiar to the lock when the plates 7 are in rest position. There again, the feeler 11 presents a pair of lugs 11a engaged in slots 12 made, parallel to the longitudinal direction 6 of the plates 7, in two parallel walls 31 inside the housing 1.
However, it will be noted that the plates 7 of the present embodiment have a length reduced almost by half: they extend only by little beyond their notch 10. In addition, the spacer members 9 have been eliminated, the plates 7 now sliding directly on the bottom 1a of the housing 1, and the small separating plates 8 make room for oblong spacer members 108 of which the pitch is determined by fitting, at their ends--each provided with a notch--in the rack notches 132, 133 fixed transversely between the walls 31.
However, the principal difference resides in the addition of an assembly of pivoting parts 134 for attacking the plates 7 and causing them to slide under the action of a flat key introduced into the lock. Parts 134 are identical bevel gear parts, mounted independently on a common pivot pin 135; they are flat, of thickness substantially equal to that of the plates 7, and with each of the latter there is associated a part 134 located in the same plane. The pitch of the parts 134 is maintained equal to that of the plates 7 on the one hand by spacer members 136 fitted in the notches of a rack 137 and traversed by the pin 135, and on the other hand by the spacer members 108 of which the ends adjacent the rack 132 pass between arms 134a belonging to parts 134, by which the latter attack the ends 7b of the plates 7. Each part 134 comprises a second arm 134b oriented substantially at right angles with respect to the arm 134a and provided with a notch 134c for receiving the key.
It will also be noted that the pivoting blade 21 for returning the plates 7 to rest is replaced by a transverse bar 121, adapted to move in translation in direction 6 in first parts 138a of guiding slots 138 made in the walls 31. The bar 121 is stressed towards the plate 7 assembly by means of a pivoting stirrup 139 with elastic return. This stirrup comprises a transverse rod 139a engaged in notches 140 of the walls 31 and bent at its ends to form arms 139b which may pivot in gaps 142 separating the walls 31 and the housing 1, about an axis materialized by rod 139a, under the action of at least one spring 141 wound around one end of the rod 139 and attached by radial ends respectively to arm 139b and to wall 31 which correspond thereto.
In order to ensure an action without dissymetry of the plates 7 on the bar 121 so that the latter moves in all cases parallel to itself, it is arranged so that there is always, during the stroke of positioning of the plates 7, advance of two plates located respectively at the ends of the identification assembly. In other words, the coded edges of the keys 3 systematically comprise a tooth 16 in the region of each of their ends.
The feeler 11 presents, at the ends of its drive edge 11b by which it may come into mesh with the aligned notches 10 of the plates 7, a second pair of lateral lugs 11c which are respectively engaged in slots 138. The first part 138a of the latter, long and parallel to direction 6, is extended, at its end adjacent the plate 7 assembly, by a second, shorter part 138b, oriented perpendicularly, then by a third part 138c, even shorter, parallel to the first part 138a (so that each slot 138 has the form of a J). Furthermore, the edge 11b of the feeler 11 is maintained applied against the sides 7a of the plate 7 assembly by a pair of leaf springs 113 located in the gaps 142, fixed to the lugs 11c and abutting on the ends of the pin 135 which project in these gaps.
In order to operate the lock, the key 3 may be introduced either, as in the case of the lock of FIG. 1, parallel to direction 6, the key then acting on the plates 7 via the arms 134a of the parts 134, or perpendicularly to direction 6, the key then acting via the arms 134b and 134a of the parts 134. In both cases, these latter pivot about pin 135, rotating on more or less large angles depending on whether each is attacked by a tooth or by a hollow of the coded edge 3a of the key 3, with the result that the code of the key is transmitted to the plate 7 assembly by all the pivoting parts 134. In the first case of introduction of the key, the latter is guided between the spacer members 108 and the nose elements 136a that the spacer members 136 comprise in the vicinity of the corresponding inlet slot 4 in the housing 1 of the lock. In the second case where the key 3 is introduced through a second slot 144 made in the lid 1b of the housing 1, it is notches 134c of arms 134b which guide the key during the movement of pivoting of parts 134. In practice, the slot 144 is accessible from outside the premises defended by the lock, while the slot 4 is accessible from inside.
Apart from this double possibility of introduction of the key, operation of the lock of the present example is the same as that of the lock of FIG. 1. By progressive penetration of the key, the notches 10 of the plates 7 are aligned, the bar 121 being shifted rearwardly by rearward movement of plates 7 a distance in accordance with the depth of the teeth of the key in advance of movement of feeler 11. The feeler 11 then pivots in the aligned notches, then is also driven in translation by the plates 7 accomplishing their complementary stroke, guided by its first pair of lugs 11a in the slots 12 and by its second pair of lugs 11c in the first part 138a of the slots 138. The feeler then repels the bolt control member which is constituted by a sliding rod 102 coupled to the feeler by simple fork link.
If the key introduced into the lock does not comprise the correct code, its penetration causes the displacement only of the bar 121, the feeler remaining immobile, retained by its lugs 11c in the second part 138b of the slots 138. At the end of the stroke that would have produced the alignment of the notches if the key used had been authentic, the bar 121 encounters a flexible rod 127 which actuates, via an articulated blade 143, a mini-switch 126 fixed on the feeler 11, which triggers off an alarm. The edge of the notches 10 by which the latter are capable of driving the feeler 11 during their complementary stroke is provided with a small bevel 10a which ensures slide without hindrance, under the thrust of the wrong key, of each plate 7 with respect to the feeler 11, blocked by its lugs 11c in the second part 138b of the slots 138, even if the drive edge 11b of the feeler were somewhat deformed or locally offset to the point of slightly penetrating in one or more notches 10 while not all the notches are aligned. This arrangement ensures that no wrong key will be stopped in untimely manner in its stroke of penetration, and will therefore cause, with complete certitude, the actuation of the alarm mini-switch 126.
As may be seen in FIGS. 3 and 4, the plates 7 comprise a coding notch not only on their longitudinal side 7a facing the feeler 11, but on their opposite side 7a' where there is provided a second notch 10'. The notches 10 and 10' are respectively located in the vicinity of the ends of each plate 7, but at a different distance, so that one corresponds to a binary 1 and the other to a binary 0. One or the other of the notches 10, 10' of each plate may be used as desired by simply turning the plate in its plane. This operation is simple to perform, as the blades 7 are maintained in position against the bottom 1a of the housing 1 only by their ends, namely at one end by the feeler 11 and the bar 121 which abut elastically thereon and, at the other end, by protuberances 145 that the parts 134 comprise, oriented substantially radially with respect to the axis 135 and allowing the plates 7 only a slight clearance to move away from bottom 1a. Consequently, after having removed the lid 1b, it suffices to lift the feeler 11 and to immobilize it in a position of retraction where its lugs 11c are housed and retained in the third part 138c of the slots 138. The plates 7 of which it is desired to reverse the binary coding 0 or 1 may then be withdrawn, turned and returned into position without the corresponding protuberances 145 opposing this. | The invention relates to a lock comprising an assembly of identification plates provided with coding notches. A flat key, presenting a coded side, pushes the plates until their notches are brought into alignment, in which a feeler then comes into mesh by a rectilinear edge. The plates, continuing to slide under the thrust of the key, take along, via the feeler, a member for controlling the bolt. An alarm device indicates any introduction of an unsuitable key. | 4 |
FIELD OF INVENTION
This invention relates to methods and apparatus for mining and in particular for open pit bench mining and apron feeders used in connection therewith.
BACKGROUND
In modern mining, geologic surveys and other techniques estimate the size and shape of mineral and/or ore configurations before their removal in a mining operation. The ore and mineral deposits exist in layers or veins at varying depths below ground. For example, deposits of coal can be divided into multiple layers of substantially horizontal planes of varying thickness and at various depths such that several deposits or veins lie at different levels spanning hundreds of feet below ground. Such layers of mineral and ore deposits are often not completely horizontal but have a pitch or slope. Because of the three dimensional sloping layers, the deposits are generally mined from the shallowest end of the deposit in a down slope direction.
In general the rock and earth disposed on top of a mineral or ore layer is referred to as “overburden”. In open pit mining, the overburden atop a first uppermost layer is removed to substantially expose a strip of the mineral or ore deposit. The exposed deposit is then accessible to be removed by mining the uncovered portion and transporting it from the mine for shipment or other processing. Overburden is then removed from above a next adjacent strip of the first layer deposit to substantially expose more of the first deposit layer for removal by mining and shipment.
In open pit mining, once a portion of the uppermost deposit layer is mined and removed, the rock that had been sandwiched between the uppermost layer and the and the next lower deposit layer is exposed and is the overburden atop the next lower layer. Accordingly, the open pit process mining continues by removing strips of that overburden to generally expose the next deposit layer, in a sequential process that continues until successive deposit layers are exhausted. Depending on the size of the deposit, each strip may be several miles in length and is typically about 100 or more feet in width depending on the type of equipment used for the mining operation and other factors such as the size and pitch of the deposit layer.
As open pit mining continues, overburden removal above each deposit layer forms steps or benches. At each step, multiple removal operations increase efficiency in mining the ore or other minerals within the deposits. Multiple operations, however, take some time, and can be cost prohibitive if projected mining yields are not sufficiently high.
The valuable deposit layers are generally much smaller than the layers of overburden. Thus, the most labor intensive task in open pit mining is the removal of the overburden.
In one conventional mining method, a bucket wheel excavator 500 , as illustrated in FIG. 1A , loads overburden 29 onto dump trucks 180 . A single bucket wheel excavator 500 may cost on the order of One-Hundred Million Dollars ($100,000,000) and require a trained crew of 6 to 8 persons to operate.
As an alternative to a bucket wheel excavator, shovels, drag lines or other bucket type equipment are often used to remove overburden. For example, FIG. 1B illustrates a conventional operation where a shovel 502 loads large oversized dump trucks 180 which deposit their materials into a hopper on a centrally located apron feeder 550 . The apron feeder 550 may feed a sizer that reduces oversized chunks of overburden to a size manageable by a conveyor 506 or other means of transport that carries the removed overburden away from the active mining area.
In a conventional mining operation, the apron feeders 550 is typically located at a semi-permanent position where overburden is trucked and deposited to a feed end of the apron feeder. When initially positioned or relocated, an apron feeder 550 is traditionally moved in a direction aligned with the feeder's conveyor operation so that they are essentially backed into a desired location. It is known in the art to provide apron feeders 552 with wheels or crawler undercarriage in line with the feeder operation for the purpose of positioning the apron feeders 552 such as illustrated in FIGS. 2A and 2B .
Applicants have recognized that it would be desirable to provide a method and system of open pit mining that reduces or eliminates the need for reliance on complicated and expensive equipment such as bucket wheel excavators and efficiently uses the necessary equipment. Applicants have in particular recognized that more efficient mining can be conducted through the creative expanded use of apron feeders in the mining operation.
Further, applicants have recognized that improved apron feeder designs may be employed to prevent costly operational stoppages due to the need for cleaning clogged material from an apron feeder.
SUMMARY
A bench mining system, mining method and related equipment are provided in which a combination of bulldozers and transversely movable apron feeders provide a primary mechanism for overburden removal. The mobility of teams of dozers along with the apron feeder, as described herein, is a significantly new and effective innovation in overburden removal. With an eye towards being able to move the entire mining operation, not only are the earth-moving pieces of equipment considered movable, but so is the entire infrastructure supporting the earth-moving equipment, including pump-houses, retaining walls, and the like.
In a preferred embodiment, a mining floor or “bench” is defined adjacent to a section of a deposit layer and overburden. Preferably, the overburden and deposit layer have a combined height relative to the bench of between 50 to 150 feet. An apron feeder is disposed on the bench in front of a pre-blasted section of overburden which preferably runs about 300 feet along the bench and the apron feeder is preferably positioned in the approximate center of the 300 feet long section. Selective blasting, as is well known in the art, is used to loosen the overburden rock and/or other material of which it is composed while leaving the deposit layer substantially intact. Preferably, the loosened section of overburden in front of which the apron feeder is positioned is about 225 feet wide, extending away from the apron feeder.
The invention further comprises bulldozers working in coordinated teams that push the overburden of the pre-blasted section onto the feed end of the apron feeder by preferably forming a natural hopper and relying on gravity to create a flow of the loosened overburden into the apron feeder. The bulldozers preferably work in defined zones and coordinate their efforts depending on the number of bulldozers employed. The apron feeder is then used to either load the bulldozed overburden onto trucks or onto a conveyor system for removal from the active mining area. After overburden removal, the substantially uncovered portion of the deposit layer is then mined using conventional methods.
The operation preferably continues along the bench by blasting further sections of overburden and transversely relocating the apron feeder in front of the next loosened section whereat further bulldozing pushes the loosened overburden into the apron feeder, which in turn, feeds the trucks or the conveyor system.
Where the layer deposits are in closely spaced intervals of less than 50 feet, a bench can be defined adjacent a section having an intermediate deposit layer within the overburden. In such case, selected blasting techniques known in the art are employed to blast the overburden atop the intermediate deposit layer as well as below the intermediate deposit layer. Then the bulldozing operation first removes the upper portion of overburden above the intermediate deposit layer and the intermediate deposit layer is mined and removed. Thereafter, the bulldozers are used to remove the lower portion of the overburden. The apron feeder can be either transversely displaced to a location for receiving another section of upper loosened overburden while the intermediate deposit layer is mined from the first section or remain at the same location for both upper and lower overburden removal operations.
Where the layer deposits are spaced at an interval of more than 150 feet, a bench can be defined where there is no deposit layer of mineral or ore within the overburden. In such case, after blasting and removal of the loosened overburden by dozing it into the apron feeder, no mining operation is required on that bench.
The blasting, dozer/apron feeder overburden removal, and deposit mining operations are preferably contemporaneously conducted on several benches where each operation is selectively transversely spaced from each other by a selected safety margin.
In order to implement the system and operation thereof, the inventive apron feeders are preferably provided with a frame that permits engagement with a crawler for displacement of the apron feeder in a direction that is transverse to a conveying direction of the apron feeder. Alternatively, the apron feeder is provided with an innovative dedicated crawler affixed thereto or other means of transverse locomotion to facilitate efficient operations as the removal of overburden proceeds along one of the benches.
Preferably, apron feeders used to conduct the inventive mining operation are provided with a self-cleaning mechanism to facilitate continuous operation without undue stoppage delays. In particular, the apron feeder is preferably provided with a scroll plate at its inlet end to catch overspill material as the apron feeder is loaded. Preferably, a “grizzly” component is mounted on an apron feeder flight that serves to break up and/or loosen material caught by the scroll plate and a wiper component is disposed on an apron feeder flight a selected distance behind the grizzly to clear the material from the scroll by pushing it back to the top of the apron feeder inlet end.
Other objects and advantages of the present invention will be apparent from the following detailed description and the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWING(S)
FIG. 1A is a perspective illustration of a prior art bucket wheel excavator used in conventional open pit mining.
FIG. 1B is a schematic illustration of a conventional open pit mining operation where a shovel loads short haul dump trucks that transport the shoveled material to a relatively stationary fixed position apron feeder in a conventional open pit mining operation.
FIG. 2A illustrates the mobility of a conventional apron feeder in line with the feeder's conveying operation utilizing a crawler.
FIG. 2B illustrates the mobility of a conventional apron feeder in line with the feeder's conveying operation utilizing wheels.
FIG. 3A is an overall perspective view of an open pit bench mining system in accordance with the teachings of the present invention.
FIG. 3B is a perspective schematic diagram of the mining system of FIG. 3A wherein a bench is adjacent to a formation that includes multiple deposit layers.
FIG. 4 is an elevated side view of an apron feeder configured for use in the mining operation depicted in FIGS. 3A and 3B .
FIG. 5A is an illustration of a preferred apron feeder and transporter.
FIG. 5B is an illustration of a transport tractor.
FIG. 5C is an illustration of a preferred apron feeder with extension walls and a sizer attached to the outlet end of the apron feeder.
FIG. 5D is an illustration of an apron feeder with extension walls.
FIG. 5E is an illustration of an alternate embodiment of the transport tractor and apron feeder.
FIG. 6A is an elevated side view of the feed end of an apron feeder fitted with a scroll element.
FIG. 6B is a perspective illustration of a self-cleaning mechanism of an apron feeder.
FIG. 6C is a perspective illustration of a top view of a preferred apron feeder.
FIGS. 7A and 7B are side and top views of an initial push to an apron feeder.
FIGS. 7C-E show three successive cuts of overburden.
FIG. 8 illustrates a top view of a successive dozer push towards an apron feeder.
FIG. 9 illustrates a top view of a first embodiment of a method of loading the apron feeder.
FIG. 10 illustrates a top view of a second embodiment of a method of loading an apron feeder.
FIG. 11 illustrates a top view of a third alternate embodiment of a method of loading an apron feeder.
FIGS. 12A-H illustrate iterative steps in a top view of a fourth method for loading a movable apron feeder.
FIGS. 13A-H illustrate iterative steps in a top view of a fifth method for loading a movable apron feeder.
FIG. 14A-I illustrate iterative steps in moving an apron feeder used in the invention.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
Overview of Operation and Equipment
FIG. 3A illustrates an open pit mining operation 20 wherein three benches 22 , 24 , 26 are at different levels relative to deposit layers 28 , 30 , 32 respectively. A layer of overburden 29 , 31 , 33 , which a removal operation carries away, covers each level of deposit layer 28 , 30 , 32 . Once the mineral or ore deposit is exposed, a mining operation removes the deposit layer 28 , 30 , 32 for further processing.
Preferably, the benches 22 , 24 , 26 are defined such that the height H of the deposit 28 , 30 , 32 and overburden 29 , 31 , 33 to which they are adjacent is between 50 and 150 feet. Each bench itself, preferably has a width of at least 100 feet extending from the deposit and overburden to which it is adjacent.
On each bench, an apron feeder is disposed in front of a pre-blasted section S 1 of loosened overburden 29 L, 31 L, 33 L which preferably has a length L which runs about 300 feet along the bench. The apron feeder is preferably positioned at the approximate center of the 300 feet long section S 1 . Preferably, the loosened section S 1 of overburden in front of which the apron feeder is positioned has a width W of about 225, extending away from the apron feeder. With the apron feeder 150 in place, bulldozers 200 push the loosened overburden 29 L, 31 L, 33 L of the section S 1 into the feed end 152 of the apron feeder 150 using one of the methods shown in FIGS. 7-13 , and discussed in more detail below.
The apron feeder 150 conveys the loosened overburden 31 L, 33 L onto trucks 180 for removal from the active mining area. Alternatively, loosened overburden 29 L is fed into a sizer 185 for removal on a conveyor system 210 . After removal of the overburden 29 L, 31 L, 33 L, a substantially uncovered section D of the deposit layer 28 , 30 , 32 is then mined using conventional methods. As a practical matter, trucks are preferred for the deeper benches, but this is dependent on the type and availability of conveying equipment to serve as an alternative means.
Selective blasting to loosen the overburden 29 , 31 , 33 is performed using techniques well known in the art to loosen the rock and other overburden material while leaving the deposit 28 , 30 , 32 intact. A second section S 2 of overburden may be loosened by blasting before the apron feeder/dozer overburden removal operation is conducted. In practice, both safety considerations and operational efficiency are preferably used to determine when and whether multiple sections of overburden are to be blasted to loosen the overburden for the overburden removal operation.
In accordance with conventional practice, the exposed sections D resulting from the dozer/apron feeder overburden removal operation will include a relatively small overlying buffer layer of rock material so that the mineral or ore deposit itself is not contaminated by the blasting process. That relatively thin buffer layer is removed using conventional methods and the mineral or ore is removed by mining in a relatively pure form and is transported out of the open pit mine for further processing and/or shipment.
Preferably on each bench 22 , 24 , 26 , the operations continue laterally along each bench and can be conducted contemporaneously at spaced locations on each bench. In general, the blasting overburden operation precedes the dozer/apron feeder overburden removal operation which in turn precedes the mining of the mineral or ore deposit. Each of the upper benches, such as benches 24 and 26 , are in fact defined by overburden for a lower bench. Accordingly, the blasting of sections of overburden 29 is performed after that area has already completed its service in forming a base for removal operations of the higher overburden and mining of the upper deposits.
As illustrated in FIG. 3A , contemporaneous operation of the three procedures, blasting, overburden removal and mining, can be laterally spaced along each bench with the active areas respectively being laterally spaced to produce a very efficient mining operation with relatively inexpensive equipment.
Variations Due to Spacing of Mineral or Ore Deposits
As noted above, the benches are preferably defined such that the adjacent overburden and deposit combination is in a range from 50 to 150 feet in height H. Where the layer deposits are spaced in close interval of less than 50 feet, a bench can be defined where there is an intermediate deposit layer within the overburden.
In such case, selected blasting techniques known in the art are employed to blast the overburden 31 atop the intermediate layer 30 i as well as below the intermediate deposit layer. Preferably, a bulldozing operation first removes the upper overburden above the intermediate deposit layer, the intermediate deposit layer is mined and removed, and then bulldozers are used to remove the lower portion of the overburden. The apron feeder may be transversely displaced to a location for receiving another section of upper loosened overburden and then transversely returned. Alternatively, the apron feeder may remain at the same location during removal of the intermediate deposit for both overburden removal operations.
For example, FIG. 3B illustrates an intermediate deposit layer 30 i within the overburden 31 adjacent to bench 24 . The intermediate deposit layer 30 i could, for example, be five feet thick having a forty feet of overburden all of which is disposed above the lower deposit layer 30 that is ten feet thick having forty feet of overburden sandwiched between the deposits 30 i , 30 . In such an example, the bench 24 is defined at the level of the lower layer deposit 30 at a depth of ninety-five feet below the top of the overburden of the intermediate deposit 30 i . After blasting to loosen both portions of the overburden 31 L in section S 1 , bulldozers are then used to first push the upper forty feet of overburden onto the apron feeder 150 stationed therebelow and the five foot thick intermediate deposit 30 i is then removed. Bulldozers then remove the remaining forty feet of overburden lying atop the lower layer deposit 30 which permits the mining of the lower deposit material.
After the overburden atop intermediate deposit 30 i is removed through the dozing operation, the apron feeder is preferably transversely moved along the bench where a next section S 2 of blasted overburden is removed through a bulldozing operation while the deposit is removed from the first five foot thick upper deposit layer 30 i . Thereafter, the bulldozers and apron feeder can be returned to the first site S 1 to remove the lower forty feet of overburden 31 L disposed on the lower deposit layer 30 .
The return of the apron feeder to finish overburden removal may be after several sections of overburden atop intermediate deposit 30 i are removed. Alternatively, a second set of dozers and a second apron feeder may be used on the same bench 24 to follow the removal of the intermediate deposit 30 i . The second set of dozers and second apron feeder would then remove the lower forty feet of overburden to permits a second mining operation to proceed with respect to removing the lower deposit layer 30 , preferably using a second set of deposit removal equipment. In either case, the transverse mobility of the apron feeders greatly facilitates the efficiency of the operation.
Where the layer deposits are spaced at an interval of more than 150 feet, a bench can be defined where there is no deposit layer of mineral ore within the overburden. In such case, after blasting and removal of the loosened overburden by dozing it into the apron feeder, no mining operation is required on that bench.
The movement of the bulldozers and apron feeders along the benches allows for efficient removal of both overburden and mineral deposits simultaneously, without extended equipment down time.
Apron Feeder Equipment
As best seen in FIGS. 4 , 5 A- 5 E, and 6 A- 6 C, a preferred apron feeder assembly 150 is shown which is designed specifically for efficient implementation of mining operations in accordance with invention by facilitating transverse apron feeder movement. The apron feeder assembly includes a feed end 152 , which receives material (overburden) that is conveyed to an outlet end 156 thus defining a conveying direction of the feeder. The apron feeder 150 is preferably comprised of 180 flights 146 , each ten inches wide, which are horizontally pivotally connected in a continuous loop. This loop defines a conveyor with a top surface 146 a that transports material from the feed end 152 to the outlet end 156 of the apron feeder 150 , and a bottom surface 146 b . The inlet end 152 of the apron feeder is conventionally enclosed within a strong metal box 155 called a “dog house” to protect it from impact and from compacted surrounding material during operation.
The apron feeder 150 is mounted at a desired angle upon a selectively configured frame 154 such as shown in FIG. 4 . The desired angle is preferably 14 to 15 degrees above horizontal. Preferably, the frame 154 supports the apron feeder so that its outlet end 156 is located at a height sufficient to fill a dump truck 180 positioned beneath the outlet end 156 . Alternatively, as depicted in FIG. 5C , a sizer 185 can be attached to the outlet end 156 of the apron feeder 150 to reduce large size chunks of overburden to a manageable size for conveying by a conveyor system 210 which is then disposed beneath a conveyor loading apparatus 186 associated with the sizer 185 .
Where a conveyor system is used, the conveyor system 210 then transports the overburden from the active mining site such as illustrated in FIG. 1B . As illustrated in FIG. 3A , the conveying system 210 can extend along a bench 22 so that the entire apron feeder 150 and sizer 185 combination can simply move transversely from in front of a section S 1 to a subsequent section S 2 for a highly efficient overburden removal process without any alteration to the conveying system. Other alternatives for transporting overburden material from the apron feeder may be used alone or in combination with the examples provided above.
The frame 154 preferably includes a selectively defined opening for access by a transport crawler 190 in a direction that is transverse to the conveying direction of the apron feeder 150 . As best seen in FIGS. 5A , 5 B, and 5 E, the transport crawler 190 preferably has treads 192 or other motive means suitable for the strip mining environment and preferably includes a vertically displaceable support bed 194 .
In lieu of having a separate crawler 190 , the apron feeder assembly 150 can include a dedicated transport crawler attached thereto. In Either case, the crawler 190 may optionally have a relatively rotatable support bed 194 associated with the transport crawler 190 to enable the crawler treads 192 to be turned relative to the apron feeder 150 to be in either a transverse or an aligned orientation with respect to the conveying direction of the apron feeder 150 . With such an option, the transport crawler 190 can move the apron feeder assembly 150 in a conventional manner as is done with the apron feeders shown in FIGS. 2A and 2B and also move the apron feeder assembly 150 in a transverse manner by changing the directional orientation of the crawler treads.
When the apron feeder assembly 150 is to be relocated on a bench, the transport crawler 190 preferably travels beneath the apron feeder assembly 150 in the space defined by the frame 154 , lifts the apron feeder assembly 150 on the support bed 194 above the bench and transversely repositions the apron feeder assembly 150 along the bench to a new location where it is lowered onto the bench. Preferably the frame 154 is structured so that the transport crawler 190 engages the apron feeder 150 directly below the center of mass of the entire apron feeder assembly 150 . As shown in FIG. 5 C, where the apron feeder 150 is used in connection with the sizer 185 , a similar crawler 188 is preferably provided to transversely relocate the sizer 185 and its associated conveyor loading apparatus 186 .
As best seen in FIGS. 5C and 5D , the apron feeder assembly 150 is preferably used in connection with massive extension walls 170 , 172 and a hydraulic assembly housing 174 having skids that permit them to be dragged by a bull dozer for placement at a desired location. Unlike conventional apron feeder walls which are semi-permanently erected such as illustrated in FIG. 2A , the walls 170 , 172 are selectively designed with a large foot print and sufficient weight to remain immobile during the dozing operations used to feed the apron feeder, while remaining sufficiently mobile and easily transportable for quickly establishing a subsequent apron feeder operational site.
The hydraulic assembly housing 174 provides the motive power to the apron feeder and typically includes both hydraulic and electrical equipment for operation the apron feeder. The hydraulic assembly housing 174 may be designed with sufficient strength and bulk to serve as one of the extension walls. However, it is preferred to provide an extension wall disposed in between the dozing operations and hydraulic assembly housing 174 .
As shown in FIG. 5D , preferably, a signal light 176 is provided which is controlled by the apron feeder operator having red and green lights. The signal light is advantageously used to signal to the operators of the bull dozers which load the apron feeder; a green light indicating when the feeder is ready to receive material and a red light indicating no loading should occur. Typically a red light indication will be given when there is a change of trucks at the outlet end.
For apron feeder operation, the walls 170 , 172 are positioned proximate the inlet end 152 of the apron feeder 150 and serve to protect the apron feeder operators and to assist in the formation of the natural hopper 40 formed during the dozing operations. The wall 170 also serves to protect the transport crawler 59 and to keep clear the area beneath the apron feeder frame 54 for the transport crawler to easily engage the apron feeder assembly 50 for transport.
Apron Feeder Self-Cleaning Mechanism
The dog box 155 provides protection to the front and sides of the feed end 152 of the apron feeder 150 . However, during the dozing operation to load the feeder, some material spills into a gap 162 defined between the apron feeder's feed end 152 and the dog box 155 . Although such spillage is a lesser problem when the apron feeder is loaded with dry material, material build up is exponentially increased where the apron feeder is loaded with wet sludge or slurry material. Typically the problem of such spillage build up results in periodic stoppage of apron feeder operation to remove built up spillage.
As illustrated in FIGS. 6A-6C , in order to prevent or reduce the buildup of overspill material, the apron feeder 150 is provided with a self cleaning mechanism that includes a spillage catching scroll 140 , a grizzly element 142 , and a wiper element 144 . The scroll element 140 comprises a strong metal sheet that is mounted to the dog box at the gap 162 and extends substantially parallel to the apron feeder fights 146 in front of the feed end of the feeder for a selected distance parallel the bottom surface 146 b of the feeder 150 . Preferably the scroll 140 is approximately 22 feet long.
The grizzly element 142 is mounted on one of the feeder flights 146 to define a row of metal teeth spanning transversely across the conveying surface. An associated wiper element 144 is mounted on one of the feeder flights 146 at a selected distance behind the grizzly 142 to define a raised blade spanning transversely across the conveying surface.
In operation, as the apron feeder is loaded, material that spills through the gap 162 is caught by scroll 140 where it collects. With each complete revolution to the apron feeder, the grizzly 142 travels along the scroll and breaks up the collected overspill material caught by the scroll. The wiper 144 then follows the grizzly 142 to push the broken up overspill back up onto the top surface 146 a of the feeder 150 . After the wiper 144 passes, the scroll 140 has been cleared to again begin to catch spillage into the gap 162 .
More than one grizzly/wiper set can be provided so that the scroll is cleared multiple times during one complete revolution of the apron feeder. Preferably, two evenly spaced grizzly/wiper sets are provided, as illustrated in FIGS. 6A and 6B .
Dozer/Apron Feeder Overburden Removal
With reference to FIGS. 7A-7E and 8 , details of a preferred dozer/apron feed overburden removal operation are illustrated. With the apron feeder 150 disposed on the bench 22 in front of the loosened section S 1 of overburden 29 L, the dozers 200 perform an initial push to form a slope 34 and natural hopper 40 . The dozers push an uppermost layer of overburden 29 L 1 towards the apron feeder 150 to form the slope 34 between the overburden section S 1 and the bench 22 . The slope 34 angles downward to form overburden chute walls 39 on either side of the apron feeder 150 . These chute walls 39 define a natural hopper or chute 40 sized and shaped to direct dozer-pushed overburden 29 to the inlet of the apron feeder 150 .
Once the dozers 200 form the natural chute 40 , the dozers 200 begin the task of removing the overburden 29 L proceeds in removal of successive layers 29 L 2 , 29 L 3 , and 29 L 4 as illustrated in FIGS. 7C-E . Gravity provides assistance in this part of the operation since the angle of repose of the material being pushed in the natural hopper 40 is such that the material naturally slides down the slope 34 to the apron feeder 150 . However, for the lower most overburden layer 29 L 4 , the dozers 200 may need to push the overburden material upward to inlet of the apron feeder. This is somewhat dependent on the thickness of the underlying deposit.
FIGS. 9-14 illustrate several alternative methods for dozing the overburden 29 L into the apron feeder 150 . The general objective to maximize the efficiency of the dozers 200 which generally means to keep the dozers in constant motion. Accordingly, communication between the apron feeder, supervisors, dozer operators, and other personnel is desirable to achieve for maximum efficiency.
FIG. 9 shows a first embodiment for dozing loosened overburden 29 L in a section S 1 into the apron feeder 150 , in which several dozers 200 operate in discreet zones 50 , 52 , 54 , 56 , and 58 . The dozers 200 in zones 50 , 54 , and 58 drive the overburden 29 L to a staging area 59 , where the dozers 200 operating in areas 52 and 56 take turns dozing the overburden 29 L through the staging area 59 into the chute 40 to the apron feeder 150 . The dozers 200 in zones 50 , 54 , and 58 preferably advance while the dozers in zones 52 and 56 retreat and vice versa to provide a system of continuous operation for all of the dozers.
FIG. 10 shows a second embodiment for dozing loosened overburden 29 L in a section S 1 into the apron feeder 150 , in which the dozers 200 in zones 52 and 56 doze the overburden 29 to the staging area 59 and dozers 200 in zones 50 , 54 and 58 doze the overburden down the chute 40 to the apron feeder 150 . Again, the dozers 200 in zones 50 , 54 , and 58 preferably advance while the dozers in zones 52 and 56 retreat and vice versa to provide a system of continuous operation for all of the dozers.
FIG. 11 shows a third embodiment for dozing loosened overburden 29 L in a section S 1 into the apron feeder 150 , in which the dozers 200 in zones 61 and 63 feed overburden 29 L to dozers 200 in zones 60 , 62 , 64 , and 66 . The dozers 200 in zones 60 , 62 , 64 , and 66 in turn feed overburden 29 L into a slot 69 . Another dozer 200 then dozes all of the overburden 29 L in the slot 69 down the chute 40 to the apron feeder 150 . The third embodiment's advantage is that it allows for more dozers 200 to work in concert with each other over a wider mining area 36 . Further, because only the dozer 200 in the slot 69 feeds the apron feeder 150 , there is little chance of a traffic jam at the slot 69 .
FIGS. 12A-H illustrate iterative steps of a fourth embodiment for dozing loosened overburden 29 L in a section S 1 to the apron feeder 150 . This embodiment uses five dozers, one in each of four zones 70 , 72 , 74 , and 76 and the fifth in a slot 75 to feed overburden 29 L to the chute 40 and down to the apron feeder 150 . The apron feeder 150 is illustrated loading dump trucks 180 . Each truck 180 leaves the area once it is full of overburden 29 L, and another takes its place.
In the step shown in FIG. 12A , all dozers advance towards the slot 75 , with the dozer 200 in zone 70 arriving in the slot 75 first, where it dumps its load of overburden. In the step in FIG. 12B , the dozer 200 in zone 70 begins its retreat through its zone 70 to gather another load, and the dozer 200 in the slot 75 prepares to drive a load to the hopper 40 . The other dozers in the zones 72 , 74 , and 76 advance. In FIG. 12C , the dozer 200 in zone 74 has dumped its load of overburden and begins its run to pick up more overburden. The dozer 200 in zone 70 continues its run to pick up overburden, while the dozers in zones 72 and 76 advance.
In FIG. 12D , the dozers in zones 70 and 76 advance and the dozers in zones 72 and 74 are still returning to pick up overburden. In FIG. 12E , the dozers in zones 70 , 74 , and 76 advance while the dozer 200 in zone 72 , having dumped its load of overburden, returns to pick up more overburden. In FIG. 12F , the dozer 200 in zone 76 has dumped its overburden, and returns to pick up overburden, while the dozers in zones 70 , 72 , and 74 advance.
In FIG. 12G , the dozer 200 in zone 76 retreats, while the others advance. Finally, in FIG. 12H , the dozer 200 in zone 70 has dumped its load and returns for another, while the other dozers in zones 72 , 74 , and 76 advance. During these various advances through the zones, the dozer 200 in the slot 75 moves back and forth, driving the dumped loads into the natural hopper 40 , with all dozers taking care not to interfere with one another and cause any work stoppage.
FIGS. 13A-H illustrate iterative steps of a fifth embodiment for dozing loosened overburden 29 L in a section S 1 to the apron feeder 150 . This embodiment uses four dozers, one in each of three zones 80 , 82 and 84 and the fourth in a slot 85 to feed the natural hopper 40 leading to the apron feeder 150 . The apron feeder 150 is illustrated loading dump trucks 180 . Each truck 180 leaves the area once it is full of overburden 29 L, and another takes its place.
The consecutive steps of dozer movements are shown FIGS. 13A-H . FIG. 13A shows the dozers 200 in zones 80 , 82 , and 84 advancing to the slot 85 , and FIG. 13B shows the same dozers further advanced towards the slot 85 . In FIG. 13C , the dozer 200 in zone 80 has dumped its load of overburden and is beginning its return for another load, while the dozers in zones 82 and 84 advance towards the slot 85 . In FIG. 13D , the dozer 200 in zone 82 begins its return for another load following the dumping of a load into the slot 85 , while the dozer 200 in zone 80 continues its return run, and the dozer 200 in zone 84 advances.
In FIG. 13E , the dozers in zones 80 and 84 advance, while the dozer 200 in zone 82 retreats for another load of overburden. In FIG. 13F , the dozers in zones 80 , 82 advance, while the dozer 200 in zone 84 begins its return for another load, having just dumped its load in the slot 85 , and FIG. 13G shows the further advance of the dozers following the step shown in FIG. 13F . Finally, FIG. 13H shows the dozers in zones 82 and 84 advance while the dozer 200 in zone 80 retreats to get another load of overburden, having just dumped its own load.
During these various advances through the zones, the dozer 200 in the slot 85 moves back and forth, driving the dumped loads into the natural hopper 40 , with all dozers 200 taking care not to interfere with each other.
The various methods can be used in a single mining site. In addition, variants thereof may be used that employ more or less dozers 200 . For example if one or more zones has a deeper cut of overburden 29 to remove, it may be advantageous to position more than one dozer in that zone, or split the zone into subzones. If too much overburden accumulates in a single dozer slot, and the dozer 200 therein falls behind, a staging area for two or more dozers may be more efficiently employed.
Apron Feeder Relocation
Once the dozers 200 remove the overburden from a section S 1 , the apron feeder 150 is then moved to a new location, such as adjacent the next section of loosened overburden S 2 . FIGS. 14A-I illustrate a preferred sequential procedure for moving the apron feeder 150 after the overburden removal operation is completed from section S 1 .
As the dozers 200 are completing the dozing of the lowest layer of the overburden 29 L of a section S 1 into the apron feeder 150 ( FIG. 14A ), a single dozer 200 or other equipment cleans out overburden spillage on the right hand side of the apron feeder until it is clear as shown in FIG. 14B .
Once the right hand side of the apron 150 is clear, a dozer 200 or other equipment removes the right hand wall 170 of the apron feeder 150 . With the right hand wall 170 removed, a dozer 200 or other equipment removes further overburden spillage, FIG. 14C , to completely clear right hand side of the apron feeder.
A dozer 200 then cleans away any overburden spillage about the left hand wall 172 and removes the wall 172 as shown in FIG. 14D . Any remaining overburden spillage 89 adjacent the hydraulic housing 174 on the left side is then also removed as shown in FIG. 14E . Thereafter, the hydraulic housing 174 is disconnected from the apron feeder 150 , and a dozer 200 removes the housing 174 for final cleaning on the left hand side, as shown in FIG. 14F . Finally, as shown in sequential steps 14 G-I a transporter 190 moves in from the right of the apron feeder, lifts it and carries the apron feeder 150 to its new location, such as adjacent another section S 2 of loosened overburden whereat the hydraulic housing 174 and walls 170 , 172 are reattached.
While specific embodiments of the invention are disclosed they are not limiting in nature. Those of ordinary skill in the art will recognize a variety of variations in parameters, equipment and processes which can be employed within the scope of the invention. | A bench mining system and mining method, particularly useful for open pit bench mining, employs a combination of bulldozers and transversely movable apron feeders to provide the primary mechanism for removal of overburden. The apron feeders are preferably equipped with a self-cleaning arrangement to facilitate continuous operation without undue stoppages. | 4 |
RELATED APPLICATIONS
This application is a divisional of copending U.S. application Ser. No. 10/014,274 now U.S. Pat. No. 6,718,199 filed on Oct. 26, 2001, which claims the benefit of the priority date of U.S. Provisional Application 60/243,682, filed on Oct. 27, 2000, the contents of which are herein incorporated by reference.
FIELD OF INVENTION
The invention relates to the measurement of electrophysiologic responses, and more particularly to enhancing the signal-to-noise ratio in such measurements.
BACKGROUND
In making a diagnosis, it is often useful to have the patient's cooperation. This is particularly true in the diagnosis of disease involving sensory pathways to the brain. For example, a straightforward way to assess a patient's hearing is to simply ask the patient whether he can hear particular tones having various frequencies and amplitudes.
In many cases, one takes for granted that a patient will be able to answer such questions. However, in some cases, a patient cannot communicate his perception. This occurs most frequently when the patient is an infant, or when the patient is unconscious. In a veterinary setting, it is rare to encounter a patient that can accurately communicate perception at all.
One approach to evaluating an infant's hearing is to make a sound and to then measure an evoked response associated with that sound. This evoked response is typically an electrophysiologic signal generated in response to the sound and traveling between the inner ear and the brain along various neural pathways, one of which includes the auditory brainstem. This signal is thus referred to as the “auditory brainstem-response,” hereafter referred to as the “ABR.”
The ABR is typically only a small component of any measured electrophysiologic signal. In most cases, a noise component arising from other, predominantly myogenic, activity within the patient dwarfs the ABR. The amplitude of the ABR typically ranges from approximately 1 microvolt, for easily audible sounds, to as low as 20 nanovolts, for sounds at the threshold of normal hearing. The noise amplitude present in a measured electrophysiologic signal, however, is typically much larger. Typical noise levels range from between 2 microvolts to as much as 2 millivolts. The resulting signal-to-noise ratio is thus between −6 dB and 100 dB
One approach to increasing the signal-to-noise ratio is to exploit differences between the additive properties of the ABR and that of the background noise. This typically includes applying a repetitive auditory stimulus (a series of clicks, for example) and sampling the electrophysiologic signal following each such stimulus. The resulting samples are then averaged. The ABR component of the samples add linearly, whereas the background electrophysiologic noise, being essentially random, does not. As a result, the effect of noise tends to diminish with the number of samples. The number of samples required to reach a specified signal-to-noise level depends on the noise level present in the samples. In principle, therefore, one can achieve a specified signal-to-noise ratio either with a small number of relatively quiet samples or with a large number of relatively noisy samples.
In practice, signal averaging techniques such as that described above are unlikely to work when the signal-to-noise ratio is worse than −48 dB. Since a minimally acceptable 5% confidence level requires a signal-to-noise ratio of at least −4 dB, this signal-averaging approach is prone to inaccuracy.
Signal averaging methods as described above perform best when the background noise is relatively constant. For example, the steady drone of an air-conditioner can readily be separated from a signal of interest. Such background noise is referred to as “stationary” noise.
The noise component of an electrophysiologic signal is often non-stationary. For example, after a few minutes of taking measurements, an infant may begin to stir, thereby momentarily increasing the background electrophysiologic noise level. The infant might then return to a deep sleep, thereby reducing the background electrophysiologic noise level.
The non-stationary nature of the noise component poses a dilemma for a clinician attempting to measure the ABR. For example, if the infant begins to stir, the clinician might suspend taking measurements to avoid contaminating data already collected with noisy data. This might prove to be a good decision if the infant were to fall back into a deep sleep, since one could then acquire additional quiet samples. However, even noisy samples can improve signal-to-noise ratio, provided that there are enough of them available. Hence, this might also prove to be a poor decision if the infant were to continue stirring. In such a case, it would have been better to have acquired the additional, albeit noisy samples. Because the behavior of an infant is, to a great extent, unpredictable, the clinician occasionally makes an incorrect guess, thereby either wasting time or needlessly corrupting acquired data.
SUMMARY
The invention is based on the recognition that, by dividing the sequence of samples that make up the signal into subsequences of samples, one can reduce the signal-to-noise ratio of an electrophysiologic signal and avoid many difficulties posed by the presence of non-stationary noise. The samples within a particular subsequence are characterized by a common range of values of a sorting parameter. Each subsequence of samples yields a statistic that is independent of corresponding statistics yielded by other subsequences of samples. These statistics, each of which corresponds to a subsequence, can then be combined in different ways to derive an estimate of an electrophysiologic response contained in the signal. The presence of non-stationary noise can, to a great extent, be compensated for by appropriately combining the statistics associated with each subsequence.
In one practice of the invention, a plurality of samples of a measured electrophysiologic signal is obtained. The electrophysiologic signal typically includes an electrophysiologic response to a stimulus. The method of the invention seeks to estimate the value of this response.
The method includes defining a plurality of bins, each of which corresponds to a range of values of a sorting parameter associated with each of the samples. Preferably, the range of values for each bin is such that each value of the sorting parameter is associated with at most one bin.
Each sample of the measured signal is then classified into one of the bins on the basis of a value of a sorting parameter associated with that sample. Then, for each bin, a statistic indicative of samples classified into that bin is maintained. On the basis of these bin statistics, the desired electrophysiologic response can then be estimated. In one particular practice of the invention, maintaining the bin statistic includes maintaining a moving average of samples in the bin.
In one practice of the invention, the sorting parameter includes a measure of noise present in the samples. The noise might be electrophysiologic noise, ambient acoustic noise, or any other noise process. The sorting parameter can also be derived from a combination of noise processes.
The estimation of electrophysiologic response can include combining the bin statistics to derive a quantity indicative of the electrophysiologic response. This might include averaging the bin statistics, or evaluating a weighted averaging of the bin statistics, with the weights being manually or automatically selected. In one practice, the weight assigned to a statistic for samples in a particular bin might be indicative of a quality of the samples in the bin. For example, the weight can be inversely proportional to a noise level associated with the particular bin. Alternatively, the weights can be selected to optimize a measure of an extent to which the quantity approximates the electrophysiologic response. The assignment of weights in a weighted average can also include excluding bin statistics associated with particular bins from being considered in evaluating the quantity indicative of the electrophysiologic response.
In another practice of the invention, a sequence of samples is decomposed into a plurality of subsequences, each of which includes samples selected on the basis of a value of a sorting parameter associated with each of the samples. The samples from each subsequence are then used to evaluate a plurality of subsequence statistics, each of which is associated with a corresponding subsequence. A subset of these subsequence statistics is then selected. The subset can include some or all of the subsequence statistics. On the basis of subsequence statistics from this set, the electrophysiologic response is then estimated.
In one practice of the invention, the subsequences are selected by selecting a noise threshold. Subsequence statistics that are associated with subsequences having noise levels above this threshold are then excluded from the subset.
The extent to which each of the selected subsequence statistics contributes to an estimate of the electrophysiologic response can be controlled. For example, one or more subsequence statistics can be weighted by an amount indicative of noise present in the corresponding subsequence. In this optional practice of the invention, subsequences statistics from subsequences that contain exceptionally noisy samples can be made to contribute less to the estimate than subsequence statistics from subsequences having samples that are not as noisy.
The method of the invention is applicable to various types of physiological stimuli. These stimuli include auditory, visual, olfactory, and gustatory stimuli, or combinations thereof.
These and other features and advantages of the invention will better understood from the following detailed description and the accompanying figures, in which:
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram of a system for acquiring electrophysiologic data; and
FIGS. 2 and 3 illustrate the data acquisition process.
DETAILED DESCRIPTION
Referring to FIG. 1 , a system 10 for acquiring electrophysiologic data for measurement of auditory brainstem response (“ABR”) includes a sensor 12 attached to an infant's scalp. The sensors 12 , which are typically scalp electrodes, are configured to detect an analog signal 13 representing ongoing electrical activity. This analog signal 13 is provided to first and second band-pass filters 14 a–b that generate first and second filtered signals 15 a–b, respectively. In one embodiment, the first band-pass filter 14 a has a passband between 180 Hz and 2000 Hz and the second band-pass filter 14 b has a passband between 30 Hz and 2000 Hz. The resulting first and second filtered signals 15 a–b are then passed to first and second analog-to-digital (A/D) converters 18 a–b for conversion into a corresponding first and second digital signals 19 a–b . These digital signals 19 a–b are then provided to a digital signal processor 20 .
Referring now to FIG. 2 , on the basis of noise measurements derived from the first digital signal 19 a, the digital signal processor 20 sorts the samples that make up the second digital signal 19 b into a plurality of bins 22 a–j each of which is associated with a band of noise amplitudes. The amplitude bands of the bins 22 a–j are selected to be non-overlapping. For the application described herein, there are ten bins. However, the number of bins 22 a–j , and the amplitude ranges associated with each bin 22 a–j , depend on the specific application of the data-acquisition system 10 . Each bin 22 a–j has an associated averaging accumulator 24 a–j that maintains a moving average 25 a–j of the samples in its corresponding bin 22 a–j. Each bin 22 a–j also has an associated counter 27 a–j that contains the number of samples N i in its associated bin 22 a–j. Referring back to FIG. 1 , the moving averages 25 a–j and the counters 27 a–j are maintained in a data buffer 26 that is available to a processing system 28 .
Note that the first and second digital signals 19 a–b need not use the same time-base. For example, the first A/D converter 18 a might sample the first filtered signal 15 a at a sampling rate that differs from that used by the second A/D converter 18 b to sample the second filtered signal 15 b. In another example, the noise analysis may be made over a portion of the first filtered signal 15 a that corresponds to a time interval that precedes and/or follows the portion of the second filtered signal 15 b that corresponds to a time interval including the data being sorted into one of the bins. Additionally, noise analysis of a portion of the first filtered signal 15 a can impact the sorting of samples from several portions of the second filtered signal 15 b. The method of the invention can thus be used with any manner of noise analysis.
During data acquisition, each averaging accumulator 24 a averages only those samples within its associated bin 22 a. Since all samples are within one of the bins 22 a–j, each sample can affect no more than one moving average 25 a–j. Since the samples in any one bin 22 a are averaged independently of samples in other bins 22 b–j, samples from one bin 22 a are prevented from contaminating the moving averages 25 b–j obtained by averaging samples from other bins 22 b–j.
Referring now to FIG. 3 , the clinician can, at any time select which of the moving averages 25 a–j available for each band are to be combined into a single average representative of an ABR measurement 38 . As shown in FIG. 3 , the clinician controls switches u i 29 a–j that selectively exclude selected bands (hereafter referred to as “excluded bands”) from consideration in evaluating the ABR measurement 38 . These switches 29 a–j are typically set to exclude from consideration all bands having a noise power above a selected threshold.
The clinician also controls weighting coefficients 30 a–j associated with each of the remaining bands (hereafter referred to as the “included” bands). These weighting coefficients 30 a–j can be controlled manually, or automatically. In either case, weighting coefficients 30 a–j can be controlled individually, or as a group. Additionally, particular combinations of weighting coefficients 30 a–j can be pre-programmed and selectively applied.
The moving averages 25 a–j of each included band, which are available in the accumulators 24 a–j, are then multiplied by the corresponding number of samples N i in each band. The results are then scaled by their corresponding weighting coefficients 30 a–j at corresponding mixers 32 a–j. The outputs 35 a–j of the mixers 32 a–j, which are proportional to the weighted averages 34 a–j corresponding to each band, the accumulated number of samples summed across all included bands, and the sum of the weighting coefficients of the included bands, are then provided to an output averaging-element 36 , the output of which is the desired ABR measurement 38 . This ABR measurement 38 is obtained by summing the outputs of the mixers 32 a–j and normalizing the result by both the sum of the weighting coefficients of the included bands and the accumulated number of samples summed across the included bands.
In the illustrated embodiment, the processing system 28 carries out the function of mixing the moving averages 25 a–j with the weighting coefficients 30 a–c, averaging the resulting products, and normalizing the result to obtain the desired ABR measurement 38 . However, without loss of generality, these functions can also be carried out by special-purpose hardware.
In one practice of the invention, the data associated with each included band is weighted by the reciprocal of the noise amplitude associated with that band. As a result, data from noisier included bands will contribute less to the ABR measurement 38 than data from less noisy included bands. This reduces the possibility that contributions from noisier included bands will excessively degrade the accuracy of the ABR measurement 38 .
In addition to processing the amplified signal received from the sensors, the digital signal processor 20 also generates repetitive auditory stimuli. These auditory stimuli are communicated to the infant through an earphone 40 in communication with the digital signal processor 20 by way of a digital-to-analog (D/A) converter 42 , as shown in FIG. 1 . The auditory stimuli can be adaptively controlled by the digital signal processor 20 in response to the measurements obtained by the data-acquisition system 10 . For example, if no ABR response appears to be evoked, the digital signal processor 20 may gradually increase the amplitude of the auditory stimuli to identify the infant's hearing threshold.
The processing system 28 also executes user-interface software for displaying, on a display monitor 48 , the results of data manipulation performed by the digital signal processor 20 . In the illustrated embodiment, the processing system 28 uses a Windows NT® operating system to execute user-interface software necessary for convenient display of data.
The data-acquisition system 10 permits retrospective control over which bands to incorporate into the ABR measurement 38 and the extent to which each band contributes to the ABR measurement 38 . By judiciously selecting the weighting coefficients 30 a–j, the signal-to-noise ratio of the ABR measurement can be optimized even in the presence of non-stationary electrophysiologic noise. As the ABR measurement 38 unfolds during the data acquisition process, the weighting coefficients 30 a–j can be adjusted in an effort to maximize the signal-to-noise ratio of the ABR measurement 38 . These adjustments can be made either in real-time, while the test is being conducted, or after the test has been terminated. The clinician conducting the test can thus experiment with different weighting coefficients 30 a–j without discarding valuable data and/or unnecessarily replicating data.
Clinical ABR testing often results in multiple tests of the same stimulus condition, with measurements from each test being contaminated by different patterns of background nose. For example, in the middle of one test, a doctor's pager may suddenly go off, while in the middle of another test, the infant may cough or sneeze.
Previously, it was counterproductive to combine data from a relatively noiseless test with data from a test having greater average noise. The data-acquisition system 10 described herein, however, permits data to be combined band by band across several such tests in a manner that optimizes the signal-to-noise ratio of the resulting ABR measurement 38 .
In conventional data-acquisition systems, weighted averaging requires a priori selection of weighting coefficients. Thus, the weighting coefficients cannot be adaptively optimized in response to the signal-to-noise ratio of the resulting ABR measurement. In contrast, the data-acquisition system 10 described herein enables weighting coefficients 30 a–j to be assigned dynamically or after the fact, thereby providing considerably more flexibility in the selection of methods for optimizing signal-to-noise ratio of the ABR measurement 38 .
The data-acquisition system 10 and method described herein are generally applicable to all clinical ABR testing, whether manual or automated. Such ABR testing can include neuro-diagnostic procedures, audiometric threshold estimation, and newborn screening.
The invention has been described in the context of measuring auditory response. However, evoked responses can arise from other stimuli, such as visual, tactile, olfactory, or gustatory stimuli. The principles described herein are applicable to measurement of evoked response resulting from whatever stimuli.
As described herein, samples are sorted into bins 22 a–j on the basis of electrophysiologic noise amplitudes. However, sorting parameters other than electrophysiologic noise amplitude can be used. Additionally, the sorting parameter can also be a multi-dimensional quantity. For example, the digital signal processor 20 may have a second input for measuring ambient acoustic noise level. In such a case, the digital signal processor 20 can assign samples to bins 22 a–j on the basis of both an electrophysiologic quantity, namely the sample amplitude, and on an acoustic quantity, namely the measured ambient acoustic noise level in the testing room. In this case, the sorting parameter is a two dimensional quantity and the bins 22 a–j can be viewed as a two-dimensional array. While this might complicate the implementation of the data-acquisition system 10 , the principle of the invention is itself unchanged.
Alternatively, the sorting parameter can be made a function of more than one variable. For example, a measurement of ambient acoustic noise in the room might be converted into an equivalent electrophysiologic noise level. This equivalent electrophysiologic noise level could then be added to corresponding samples from the digital signal before those signals are sorted into bins 22 a–j.
It is to be understood that the foregoing description is intended to illustrate and not limit the scope of the invention. The invention is defined by the scope of the following claims. Other aspects, advantages, and modifications are within the scope of the following claims. | A method for estimating an electrophysiologic response contained in a measured signal includes obtaining a plurality of samples and defining a plurality of bins, each of which corresponds to a range of values of a sorting parameter associated with each of the samples. Each sample of the measured signal is then classified into one of the bins on the basis of a value of a sorting parameter associated with that sample. Then, for each bin, a statistic indicative of samples classified into that bin is maintained. On the basis of these bin statistics, the desired electrophysiologic response can then be estimated. | 0 |
BACKGROUND OF THE INVENTION
This invention relates to shot peening and, more particularly, to shot peening a vehicle suspension component using ceramic peening media to increase fatigue properties of the suspension component.
Suspension components, such as coil springs, stabilizer bars, torsion bars, and the like, have considerable fatigue resistance to withstand repeated cycles of mechanical stress. For example, coil springs are manufactured from steel rods by heating and forming the rods into the desired coil shape. The coil springs are then heat treated and shot peened with steel particles to increase the fatigue resistance. The steel particles impact the surface of the coil spring, thereby compressing the surface and creating a residual compressive surface stress that offsets mechanical tensile stresses to resist fatigue.
Although using steel particles is effective for increasing resistance to fatigue, there are opportunities for improvement. For example, one problem related to the use of steel particles is that the steel particles wear the peening equipment at a rather quick rate. Depending on the frequency of use, portions of the peening equipment may require replacement over relatively short time intervals, which increase operating expenses.
Additionally, the level of fatigue resistance that is attainable using steel particles is limited. For example, using larger diameter steel particles would produce a greater amount of residual compressive surface stress. However, the gain in fatigue resistance from the greater residual compressive surface stress is offset by an increase in surface roughness due to impact with the larger diameter steel particles. Thus, steel particles have limited effectiveness for improving fatigue resistance.
Therefore, there is a need for a peening method that provides less wear on the peening equipment and produces suspension components having enhanced fatigue resistance. The disclosed examples address this need while avoiding the shortcomings and drawbacks of the prior art.
SUMMARY OF THE INVENTION
An example method of manufacturing a vehicle suspension component, such as a helical coil spring, includes the step of rotating a first impeller to project ceramic peening media in a first direction toward the suspension component to peen a surface section of the suspension component and thereby increase a fatigue resistance of the suspension component.
In one example, the vehicle suspension component is peened with metal or ceramic peening media having a first average size, followed by peening with ceramic peening media having a second average size that is smaller than the first average size. The first peening media compresses the surfaces of the automotive suspension component to provide deep residual compressive surface stress, and the second ceramic peening media smoothes those surfaces to provide a desirable surface roughness while also increasing residual surface stress. The ceramic peening media also produces less wear on the peening equipment. The combination of the first stage peening to obtain deep residual compressive stress and the second stage ceramic peening to obtain low surface roughness and high residual surface stress provides an increase in the fatigue resistance.
The disclosed examples thereby provide less wear and suspension components having enhanced fatigue resistance.
BRIEF DESCRIPTION OF THE DRAWINGS
The various features and advantages of this invention will become apparent to those skilled in the art from the following detailed description of the currently preferred embodiment. The drawings that accompany the detailed description can be briefly described as follows.
FIG. 1 is a perspective view of a vehicle suspension system.
FIG. 2 is a schematic view of an example peening device utilizing one or more blast wheels.
FIG. 3 is a schematic view of another peening device in which the blast wheels are laterally angled.
FIG. 4 is a schematic view of a duplex peening process.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 illustrates selected portions of an example vehicle suspension system 10 , such as a suspension system of an automobile. The suspension system 10 includes a frame 12 that supports lower control arms 14 and upper control arms 16 . A knuckle 18 is secured between each respective lower control arm 14 and upper control arm 16 , and each knuckle 18 supports a wheel end 20 . Although a four-bar suspension arrangement is shown, it is to be understood that the present invention may be utilized with any suspension arrangement for various types of vehicles.
A stabilizer bar 22 is arranged laterally between the lower control arms 14 . The stabilizer bar 22 includes a lateral bar portion 24 supported on the frame 12 by brackets 26 . The stabilizer bar 22 also includes arms 28 that are secured to the lower control arms 14 by stabilizer bar links 30 . The stabilizer bar links 30 transmit vertical inputs from the lower control arm 14 and the upper control arm 16 to the stabilizer bar 22 to provide vehicle stability during roll conditions. A coil spring 32 is located between the lower control arm 14 and the frame 12 on each side of the vehicle suspension system 10 for absorbing vibration and impact transferred through the wheel ends 20 . Given this description, one of ordinary skill in the art will recognize that other types of coil springs having different designs, coil thicknesses and coil diameters than the coil springs 32 may alternatively be used.
The coil springs 32 are manufactured from a steel rod using known forming and heat treatment processes, for example. The coil springs 32 of the disclosed embodiment are peened using a peening process to increase a fatigue resistance of the coil springs 32 . The peened coil springs 32 have a surface hardness of about 46-57 on the Rockwell Hardness C-scale (HRC). The hardness provides the benefit of resisting wear and abrasion, while maintaining a desirable level of toughness.
FIG. 2 illustrates an example of the peening process. In this example, the peening process utilizes a peening device 42 that includes a blast wheel 44 having impellers 46 . The impellers 46 are driven to rotate at a preset rotational velocity and thereby project ceramic peening media 48 at a corresponding projection velocity and projection rate through an opening 50 in a nominal direction 52 . For example, the nominal direction 52 refers to an average or preset direction, and a portion of the ceramic peening media 48 may deviate within a tolerance of the nominal direction 52 . In one example, the projection velocity is greater than 50 m/s (meters per second) and the projection rate is between 40 kg/min (kilograms per minute) and 200 kg/min to produce a desirable level of fatigue resistance. In a further example, the projection velocity is between 60 m/s and 80 m/s to produce a desirable level of fatigue resistance.
A supply arrangement 54 supplies the ceramic peening media 48 , such as beads or particles, from a storage reservoir 56 to the blast wheel 44 . The ceramic peening media 48 is manufactured from a known ceramic material, such as zirconium silicate, zirconium dioxide, silicon oxide, silicon carbide, aluminum oxide, other known inorganic non-metallic material, or a combination thereof. In a further example, the ceramic peening media 48 is ZIRSHOT® ceramic beads, available from Saint-Gobain.
A conveyer 58 transports the coil springs 32 (shown schematically) through the peening device 42 such that the projected ceramic peening media 48 impacts surfaces of the coil springs 32 to provide a residual compressive stress at surfaces of the coil springs 32 . In the illustrated example, the conveyor 58 rotates the coil springs 32 about longitudinal axis 60 to provide uniform peening of the surfaces of the coil springs 32 . Although the disclosed examples pertain to the coil springs 32 , it is to be understood that other components within the vehicle suspension system 10 may likewise be peened to increase fatigue resistance.
Using the ceramic peening media 48 provides the benefit of increased fatigue resistance compared to previous peening processes that do not utilize ceramic media. For example, the ceramic peening media 48 has an average particle size of about 150-230 micrometers. Preferably, the average particle size is about 210 micrometers. The relatively small size compared to metal peening media provides a surface roughness on the coil springs after peening that is less than about 0.025 micrometers. In one example, the surface roughness of the coil springs 32 is about 0.015-0.021 micrometers. The term “about” as used in this description to describe roughness refers to normal variability associated with measuring roughness.
Optionally, a second blast wheel 44 ′ that is similar to the first blast wheel 44 is used to project ceramic peening media 48 ′ in nominal direction 62 , which is transverse to direction 52 , for example. The second blast wheel 44 ′ may be located before or after the first blast wheel 44 relative to the movement of the conveyor 58 . Each of the blast wheels 44 , 44 ′ may be vertically oriented directly above the conveyor 58 as in the illustrated example, or angled laterally as illustrated in FIG. 3 . Combinations of vertical and lateral orientations are also contemplated.
Using the blast wheels 44 , 44 ′ and different directions 52 , 62 provides the benefit of uniformly peening all of the surfaces of the coil springs 32 . Given that peening is a “line of sight” process, using the different directions 52 , 62 permits the ceramic peening media 48 to access all of the surface portions of a given coil spring 32 . Given this description, one of ordinary skill in the art will recognize that one or more additional blast wheels may be used in conjunction with blast wheels 44 , 44 ′, depending on the design needs of a particular coil spring 32 .
FIG. 4 illustrates an example duplex peening process that includes two peening devices 72 a , 72 b that are similar to the peening device 42 described above. The first peening device 72 a corresponds to a first peening stage and the second peening device corresponds to a second peening stage. In this example, the first peening device 72 a includes three blast wheels 74 a , 74 b , and 74 c (shown schematically) that project metal peening media 76 , such as steel media, in corresponding nominal directions 78 a , 78 b , and 78 c . A conveyer 58 ′ transports the coil springs 32 (shown schematically) through the first peening device 72 a such that projected metal peening media 76 impacts the coil springs 32 to provide a residual compressive stress at surfaces of the coil springs 32 . The conveyor 58 ′ rotates the coil springs 32 as described above.
The metal peening media 76 has an average particle size of about 560-600 micrometers. Preferably, the average particle size is about 584 micrometers. The relatively large size of the metal peening media 76 compresses the surfaces of the coil springs 32 to provide a residual compressive surface stress of S 1 and a surface roughness after peening that is greater than about 0.025 micrometers, up to 0.031 micrometers, for example. Given this description, one of ordinary skill in the art will recognize that other sizes of the metal peening media 76 , or other peening media, may alternatively be used to provide different residual compressive surface stresses and different surface roughnesses in the first stage of peening.
After peening the coil springs 32 using the first peening device 72 a , the conveyor 58 ′ transports the coil springs 32 to the second peening device 72 b . The second peening device 72 b includes three blast wheels 82 a , 82 b , and 82 c (shown schematically) that project ceramic peening media 48 in corresponding nominal directions 78 a , 78 b , and 78 c such that the projected ceramic peening media 48 impacts the coil springs 32 . The conveyor 58 ′ rotates the coil springs 32 as described above. Optionally, the metal peening media 76 of the first stage and the ceramic peening media 48 of the second stage are collected after a given peening cycle, filtered to remove fines, and reused in a subsequent peening cycle.
As described above, the ceramic peening media 48 has an average particle size of about 150-230 micrometers, and preferably about 210 micrometers. In this example, the metal peening media 76 of the first stage has already compressed the surfaces of the coil springs 32 . In the second stage, the ceramic peening media 48 provides additional compression. In addition, the smaller, ceramic peening media 48 smoothes the surfaces of the coil springs 32 and provides a surface roughness that is about 0.015-0.021 micrometers.
In the disclosed example, using a combination of the metal peening media 76 in the first stage to obtain deep residual compressive stress and the ceramic peening media 48 in the second stage to obtain high residual surface stress and low surface roughness provides the synergistic benefit of significantly increasing the fatigue resistance of the coil springs 32 . In one example, the synergistic benefit is achieved by using approximately equal projection velocities in the first and second stages. That is, the ceramic peening media 48 is projected with a velocity that is within about +/−20 m/s of the velocity of the metal peening media 78 . In a further example, the projection velocities are between 60 m/s and 80 m/s to produce a desirable level of fatigue resistance.
Additionally, using the ceramic peening media 48 provides the benefit of reducing abrasive wear on the peening equipment compared to using metal peening media. The ceramic peening media 48 is smaller and less dense than a metal media, and therefore impacts the blast wheels 44 , 82 a , 82 b , and 82 c , conveyor 58 ′, and other components with less energy for a given projection velocity. This reduces the rate of abrasive wear and extends the useful life of the impellers, conveyor 58 ′, and other components. Further, the ceramic peening media 48 extends the life and reduces surface discontinuities and damage on the blast wheels 44 , 82 a , 82 b , and 82 c (wear due to abrasion), resulting in improved blasting performance over the time an individual impeller is used. In use, cast metal impellers stay much smoother, resulting in less “splaying” of the ceramic peening media 48 off the impellers in a random fashion as the blast wheels 44 , 82 a , 82 b , and 82 c rotate. Thus, a greater amount of the ceramic peening media 48 will leave the tip of the impeller in the desired/theoretical projection direction and with the desired velocity, which results in improved peening.
Although a combination of features is shown in the illustrated examples, not all of them need to be combined to realize the benefits of various embodiments of this disclosure. In other words, a system designed according to an embodiment of this disclosure will not necessarily include all of the features shown in any one of the Figures or all of the portions schematically shown in the Figures. Moreover, selected features of one example embodiment may be combined with selected features of other example embodiments.
The preceding description is exemplary rather than limiting in nature. Variations and modifications to the disclosed examples may become apparent to those skilled in the art that do not necessarily depart from the essence of this disclosure. The scope of legal protection given to this disclosure can only be determined by studying the following claims. | A method of manufacturing a vehicle suspension component, such as a helical coil spring, includes the step of rotating a first impeller to project ceramic peening media in a first direction toward the vehicle suspension component to peen a surface section of the vehicle suspension component. In one example, the vehicle suspension component is peened with metal peening media before peening with the ceramic peening media. | 1 |
BACKGROUND OF THE INVENTION
The invention relates to ventilation means for dynamoelectric machines and more particularly to a combination baffle and deflector that embodies ventilating air guiding means integrally formed with screen and fin structures that are operable to protect the interior of a dynamoelectric machine on which the combination baffle and deflector is mounted from injury due to entry therein of rodents, snakes or similar hazardous intruders.
In the design and manufacture of dynamoelectric machines it has become customary to utilize various forms of air baffles and deflectors to guide ventilating air through and around various heated components of the machines to optimize the ventilation of such parts. In general, such baffle and deflector members are conventionally arranged in or adjacent to the end turn cavities of a motor or generator housing to direct streams of incoming cooling air onto the end turns of the motor stator and rotor and thence through exhaust ports to the exterior of the machine. Frequently, such ventilating arrangements force the exhaust air over the exterior surface of the machine housing to help remove heat conducted to the housing from the stator laminations of the machine. Many examples of such prior art ventilation arrangements for electric motors are available. One example of such a conventional air inlet baffle and deflector arrangement is shown is U.S. Pat. No. 3,725,706--Lukens which issued Apr. 3, 1973 and is assigned to the assignee of the present invention.
Typically, such prior art ventilating arrangements for dynamoelectric machines either do not utilize screens or other means to protect the interior of the machines from damage by intruding small animals or other foreign objects, or if such screen arrangements are used they are simply added as a separate component at a point in the air flow stream spaced from the air baffle and deflector elements. Also, in such prior art structures it has been normal practice to provide separate air baffle members and air deflector members. For example, in the afore-mentioned Lukens patent an air baffle member 23 is used to force cooling air inward toward the motor shaft while separate air deflectors are mounted adjacent the tips of a cooling fan 22 and on the circumference of end caps 18 to direct the exhaust air axially along heat-radiating ribs 21 on the motor. In addition to being relatively expensive to manufacture, particularly in a vertical motor design where similar air flow paths would normally be formed by coring operations on the end caps, such articulated ventilating arrangements are fairly complex to install and may be subject to increased maintenance expense normally associated with a multipart machine in which the parts are vibrated continuously against one another or relative to other components of the machine. This problem is compounded in electric motors where magnetic flux adds to the causes of vibration. As will be apparent from the following description of the invention, to the extent that components of such machines can be made of a non-magnetic material such as moldable plastics, this additional source of vibration can be minimized. Thus is can be seen that it would be desirable to provide a ventilation means for a dynamoelectric machine that would overcome these drawbacks of known prior art ventilating arrangements.
OBJECTS OF THE INVENTION
A primary object of the invention is to provide a combination cooling air baffle and deflector for dynamoelectric machines that overcomes the above-mentioned disadvantages of prior art ventilating arrangements for such machines.
A further object of the invention is to provide a combination baffle and deflector having integrally formed air-guiding vanes, rodent-blocking screens and fins that protect the air flow passageways of the machines from penetration by such animals.
Another object of the invention is to provide an improved dynamoelectric machine having a combination baffle and air deflector that efficiently and inexpensively optimizes the ventilating characteristics of a coolant air stream while preventing wildlife from entering the machine.
Additional objects and disadvantages of the invention will be apparent to those skilled in the art from the description of it that follows considered in combination with the attached drawings.
SUMMARY OF THE INVENTION
In one preferred embodiment of the invention a combination air baffle and deflector is provided with integral base, leg and rim portions that cooperate to deflect and guide cooling air in an efficient, optimum manner due to the characteristic features of the structure. Moreover, in a combined form of the invention the baffle and deflector is assembled with a dynamoelectric machine such as an electric motor to form part of the ventilating means of the machine. As thus assembled, the combination baffle and deflector is operable to guide inlet air around the end turns of a motor stator and to exhaust the air axially along the exterior of the motor housing. Also, the combination baffle and deflector includes unique screen and fin arrangements that operate effectively to block the entry of rodents and other small wildlife from the interior of the motor housing.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is an axial cross sectional view of a dynamoelectric machine having mounted therein a combination baffle and deflector constructed pursuant to the teaching of the present invention.
FIG. 2 is a fragmentary, top plan view of a segment of the combination baffle and deflector illustrated in its assembled position in FIG. 1.
FIG. 3 is a cross sectional view through one side of the combination baffle and deflector taken along the plane 3--3 illustrated in FIG. 2.
FIG. 4 is an axial cross section, in reduced scale, of the combination baffle and deflector shown in FIG. 1.
FIG. 5 is a fragmentary, perspective view of the combination baffle and deflector shown in FIGS. 1-4.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to FIG. 1, it will be seen that there is shown a dynamoelectric machine 1 having a laminated stator 2 provided with a conventional stator winding 3 mounted thereon, a suitable rotor 4 mounted for rotation on a shaft 5 that is journaled in housing end caps 6 and 7 and rotatably supported on guide bearing 8 and thrust bearing 9, respectively, mounted at the bottom and upper ends of the machine. The housing for machine 1 is completed with a central cylindrical housing portion 10 that is shrunk fit or otherwise suitably clamped around the laminated stator 2 in any conventional manner. To optimize the heat dissipating characteristics of the machine, the central portion of the housing 10 is provided with integral, axially extending ribs 10A projecting radially outward therefrom.
Cooling air is drawn into the housing of machine 1 by a pair of fans 11 and 12 mounted, respectively, on the opposite ends of rotor 4. Access for the cooling air is provided by wall means 6A in end cap which operates in combination with the upper end of the central housing portion 10 to define a plurality of air inlet passageways around the end cap-supporting struts 6B and 6C, etc. that are used to space the main body portion of end cap 6 from the upper end of the central housing portion 1. In this form of the invention the end cap 6 is secured to the central housing portion 10 by a plurality of bolts, such as the bolt 13 illustrated in FIG. 1 to the left side of end cap 6.
From the description of the invention that follows, it will be appreciated that although the components of dynamoelectric machine 1 described above are exemplary of one type of machine with which the combination baffle and deflector of the invention will operate, other types of dynamoelectric machines are equally suitable for use in practicing the invention described herein. Thus, various conventionally available dynamoelectric machines or various combinations of component parts thereof can be used in lieu of the particular structures and arrangements illustrated in FIG. 1 and described generally above.
Pursuant to one aspect of the present invention there is shown assembled in combination with the motor 1 a combination baffle and deflector 14 that will now be described in detail with reference to FIGS. 2, 3, 4 and 5 of the drawing. Subsequently, the optimum operating characteristics of the cooling and wildlife-blocking features of the combination baffle and deflector 14, as used in association with a dynamoelectric machine such as machine 1, will be discussed in more detail with reference to FIG. 1.
As shown best in FIGS. 3 and 4, the combination baffle and deflector 14 used for guiding ventilating air in and around dynamoelectric machine 1, comprises an integral annulus (designated 14) that is formed of a thermosetting plastic material that is molded into rigid form in the preferred embodiment of the invention, but that may be formed of any suitable moldable material in alternative embodiments of the invention. The annulus 14 has a generally U-shaped configuration as seen in cross section on the radial plane 3--3 through its central axis and one side thereof, as depicted in FIG. 3. This generally U-shaped configuration consists of a base portion 14A that is generally flat, as shown, in this embodiment. Integrally formed with the base portion 14A is an outer leg portion 14B, and an inner leg portion 14C that is sloped toward the center of the annulus 14, away from the base portion 14A. Finally, an integral rim portion 14D extends outward from the junction of the outer leg portion 14B and the base portion 14A. In order to perform the desired air baffling and deflecting functions of the invention, the base portion 14A and the inner and outer leg portions 14B and 14C are made substantially impervious to air. On the other hand, the rim portion 14D is provided with suitable wall means that define apertures through the rim portion to enable air to pass through it. Several of these apertures are designated by the number 15 in FIGS. 2, 3 and 5. In the preferred embodiment of the invention described herein the apertures 15 are defined by a plurality of radially extending spokes 16, 16A, 16B etc. (FIGS. 2 and 5) that are respectively disposed in a plane that extends substantially perpendicularly outward from the outer leg portion 14B of annulus 14 as clearly seen in FIG. 3. Cooperating with the spokes 16 is a first outer ring portion 17 supported on the outer ends of the spokes 16, 16A etc. and a second ring portion 18 that is supported on the spokes intermediate their respective ends to define the apertures 15 in the form they are arranged as a grid structure on rim portions 14D.
Pursuant to the present invention, the apertures 15 as defined by the spokes and supported rings 17 and 18 are made sufficiently small effectively to block the passage of small animals, birds or snakes therethrough so that these objectionable intruders are prevented from passing the rim portion when it is mounted in an air inlet passageway, such as the passageway defined by wall means 6A of motor end cap 6 illustrated in FIG 1. Thus, it will be understood that various other suitable configurations or grid structures may be formed in the rim portion 14D to afford this desirable objective of the invention in alternative embodiments thereof.
A further unique feature of the present invention is the provision of a plurality of generally flat-sided fins 19, 20, 21 etc. disposed between the outer leg portion 14B and the base portion 14A of the annulus 14, with the flat side of each fin being substantially perpendicular to the base portion as illustrated by the phantom view in FIG. 2, the side elevation views in FIGS. 3 and 4 and the perspective view of FIG. 5. The purpose of the fins 19 is to provide a means for effectively blocking the entry of undesirable wildlife through the exhaust air passageways defined by the combination baffle and deflector when it is mounted on a motor, such as the motor 1 shown in FIG. 1. Thus, it will be appreciated that a variety of suitable configurations for the fins 19, 20. 21 etc. may be used in alternate embodiments of the invention. However, in the preferred embodiment being disclosed here, the maximum length of each of the fins 19-21 etc. is at least 25 percent of the width of the base portion 14A of the annulus and preferably is about one half the radial width of the base portion, as shown. Likewise, the width of each of these fins, measured parallel to the outer leg portion 14B, is at least 25 percent of the length of the outer leg portion and preferably at least one half as long as outer leg portion 14B. It has been found preferable, as disclosed in this embodiment of the invention, to support each of the fins 19-21 etc. on both the base portion 14A and the outer leg portion 14B so that the fins are rigidly held in position to resist forces that may be exerted on them by animals attempting to detroy or deflect the fins. To accomplish such a support in the disclosed form of the invention, the fins are molded integrally with the other portions of the annulus 14, but it will be understood that other suitable support means can be used to afford this function.
Now, referring again to FIG. 1, an embodiment of the invention will be described in which the combination baffle and deflector annulus 14 is assembled in combination with a motor 1. In this preferred assembly, the base portion 14A of the annulus is positioned adjacent to the upper end of the central housing portion 10 of the motor. At the same time the outer leg portion 14B of the annulus is disposed around the outer edges of one end of the cooling ribs 10A on the central housing portion 10, as shown, and each of the fins 19-21 etc. is positioned, respectively, intermediate the ends of two of the ribs (10A) on central housing portion 10. Actually, in order to most effectively prevent the entry of animals into the motor 1, the fins should each be placed at approximately the midpoint of the channel defined by the two ribs adjacent to it thereby to divide the cross sectional area of the potential entry tunnels in half. To best assure the effectiveness of this screening arrangement, the fins 19-21 etc. are formed so that each of them is approximately equal in radial length to the radial width of the ribs 10A of a motor, such as the motor 1, with which they are designed to be associated. Alternative relative radial widths of the ribs and axial lengths of associated fins of the baffle and deflector annulus may be used in alternate embodiments of the invention, as determined desirable by the particular nature of screening size needed in given circumstances.
Finally, to assure this optimum positioning of the annulus 14, suitable holding means, such as the screw 22 illustrated in FIG. 1, are used to fix the relative position of the ribs and the fins by fastening the annulus 14 to the end cap 6 of motor 1 which, in turn, is secured in the manner noted above by screws (13) to the central housing portion 10.
Those skilled in the art will recognize that various modifications and alternative forms of the invention may be produced from the description of it given herein; therefore, it is my intention to encompass within the scope of the following claims the true limits of the invention. | A combination baffle and deflector for guiding ventilating air in and around a dynamoelectric machine is characterized by incorporating an annulus having integrally formed base, leg and rim portions that enable the baffle and deflector member to be mounted on one end of a dynamoelectric machine to provide optimum air flow control while also providing apparatus for blocking entry of rodents, snakes, and other similar foreign objects into the machine. In a combined form of the invention the unique baffle and deflector member is assembled with an electric motor that has a plurality of axially extending, radially projecting cooling ribs on an exterior surface of its housing. Fin portions integrally formed with the baffle and deflector member are disposed to cooperate with the cooling ribs on the motor housing to provide an efficient and inexpensive screen over one portion of the ventilating passageways through the motor. | 7 |
CROSS REFERENCE TO RELATED APPLICATION
The present application is related to co-pending U.S. patent application Ser. No. 09/234,229, titled “System and Method for Optimizing Personal Area Network Electrostatic Communication,” which was filed on Jan. 20, 1999, which is assigned to the same assignee as the present invention, and which is incorporated herein by reference in its entirety.
FIELD OF THE INVENTION
The present invention generally relates to the field of electronic communication systems. More specifically, the invention relates to the use of personal encoded identification media for providing time-limited access to people, objects, information, services, and other resources. The invention has particular applicability to credit cards, dining cards; telephone calling cards; health cards; driver's licenses; video store cards; car access cards; computer access cards; building access cards, identification tag; key fob and like ID badges and tokens.
BACKGROUND OF THE INVENTION
The use of electromagnetic fields as a communication medium is ubiquitous in today's society. Both communication over physical media, such as wires, and wireless communication, such as broadcast radio, television and satellite, infrared, and ultrasound, are widespread and commonplace. Such communication may be made over long distances, or over much shorter distances, such as closed-circuit television or a client human being using a terminal to communicate with a local server. Other media may be used for wireless communication, including acoustic such as ultrasonic, sonic, and subsonic, electric field and magnetic field.
In some situations, a user is physically present at a terminal or communication system, for the duration of a transaction. The terminal is available to all interested users, and a user having need of the service provided by the terminal seeks it out and uses it to make the transaction. Examples of such terminals are public pay telephones and Automatic Teller Machines (ATM).
Many transactions involve the use of a portable instrumentality or an input device such as a keypad, for verifying the identity of the user in order to authorize the transaction, make a charge for the service, etc. Often, this portable instrumentality takes the form of a card or badge bearing a magnetically encoded stripe, which is readable by the terminal. For instance, a user seeking cash from an ATM stands before the ATM, inserts his/her card, and keys in a Personal Identification Number (PIN), followed by menu-prompted transaction instructions. Authorization of the transaction is based on a verification of the user's identity based on a combination of (i) the user's possession of the authorizing card, and (ii) the user's knowledge of the PIN.
However, this form of communication could expose the user to physical hazards, and the card to theft and unauthorized access. U.S. Pat. No. 5,796,827 to Coppersmith et al, which is incorporated herein by reference, addressed this problem by providing an apparatus and method for utilizing the human body as a communication medium to transmit information related to the user, to protect the user's privacy and the confidentiality of the information against unauthorized access. The patented communication system produces small currents in the human body, externally induced by electrostatic field coupling, which provides for wireless identification and authentication among proximate devices. The system encrypts data and provides for easy and rapid receipt and authentication of the encrypted data, with sufficient capacity to handle millions of unique transmitter codes.
U.S. Pat. No. 5,657,388 to Weiss describes an attempt at improving the secure access to electronic information by utilizing a token that may contain a public ID, to provide secure access by authorized users to a selected resource. The token stores a secret user code in machine readable form, which code is read by a token processor. The token processor receives a time-varying value and an algorithm, both of which may be stored or generated at either the token or the token processor, and a secret personal identification code which may be inputted at the token or the token processor. The secret user code, time-varying value, and secret personal identification code are then algorithmically combined by the algorithm to generate a one-time nonpredictable code which is transmitted to a host processor. The host processor utilizes the received one-time nonpredictable code to determine if the user is authorized access to the resource and grants access to the resource if the user is determined to be authorized.
However, the systems described in U.S. Pat. No. 5,657,388 and other similar publications still rely on the transmission of a public key or other public ID for proper authentication. The public ID which typically includes a static code value is also subject to surreptitious detection, and can be used to associate a particular user or object with a specific transmission, compromising the user's or object's privacy.
While conventional devices have provided significantly enhanced security for data processing systems, databases and other information resources there still remains an unsatisfied need for a further improved system that eliminates the need for public keys or IDs, thus further minimizing invasion of privacy, security risk and exposure.
As an example, though identification badges that wirelessly transmit an ID code can be used to locate someone in a building, such as to find doctors in a hospital, maintenance people in a factory, or key personnel in an office, individual privacy might be compromised in that the badge users can be tracked all the time without their control or consent. It would therefore be desirable to have a system that limits access to tracking information, such as allowing a badge user to be tracked for limited time periods that are determined by this particular user.
SUMMARY OF THE INVENTION
One feature of the present invention is to provide a limited tracking system and associated method that enable the use of personal encoded identification media to limit access to tracking information.
A more specific feature of the limited tracking system is to provide concurrent time-limited access to a large number of people, objects, information, services, and other resources, which are herein collectively referred to as “resources”. The limited tracking system has particular applicability to credit cards, dining cards, telephone calling cards, health cards, driver's licenses, video store cards, car access cards, building access cards, computer access cards, and like identification badges or cards.
For example, the limited tracking system could allow persons to be tracked only during business hours but not during lunch or break times. This will allow privacy of movement during the employee's personal time. Alternatively, the limited tracking system could be automatically tied to events in a person's or group's calendar, to allow tracking during important meetings or phone calls, so that an assistant might try to locate individuals during these important events. The limited tracking system can be included in laptops, desktops or processors, to track assets in buildings.
Another feature of the limited tracking system is to distribute tracking access to multiple sources and limit the vulnerability of a user's or object's privacy if one or more of the sources are compromised.
The foregoing and other objects and features of the present invention are realized by a limited tracking system that includes a transmitter module incorporated in an ID badge, card, or label, and a receiver module incorporated in a secure server. The transmitter module contains a microprocessor and a watch crystal that keeps track of time. The microprocessor encrypts time with a private key, and transmits the encrypted time once every ten seconds. The transmission can be any wireless means, including infrared, radio frequency, electric field, magnetic field, ultrasonics, and so forth. The limited tracking system is capable of individually tracking a large number of receivers that are distributed about one or multiple tracking environments or ranges.
The secure server stores the private keys of all the users (or receivers). The user of the badge can give a third party, or multiple parties, referred to herein as finder, access to the user for specified time periods. As an example, if the user wishes to give the finder tracking access for specific time periods, the user instructs the server to deliver a list of encrypted codes with the user's private key for these time periods. This list can be transmitted or otherwise provided to the finder for storage on the finder's own server. When the finder detects a transmission from the user's badge, the finder's server looks up the current value of the user's badge from the list and compares it to the encrypted code it received from the badge. If a match exists, the finder would have identified and located the user.
BRIEF DESCRIPTION OF THE DRAWINGS
The various features of the present invention and the manner of attaining them will be described in greater detail with reference to the following description, claims, and drawings, wherein reference numerals are reused, where appropriate, to indicate a correspondence between the referenced items, and wherein:
FIG. 1 is a schematic illustration of an exemplary operating environment in which a limited tracking system of the present invention may be used, showing a plurality of badges in communication with a base receiver, a processor, and a server, for access authentication;
FIG. 2 is a high level functional block diagram of an exemplary badge Bn shown in communication with a receiver module that forms part of the base receiver of FIG. 1 ;
FIG. 3 is a high level functional block diagram of an exemplary badge Bn;
FIG. 4 is a flow chart illustrating an exemplary encryption process implemented by the badge of FIG. 3 according to the present invention, for transmitting an encrypted code specific to each badge;
FIG. 5 is a flow chart illustrating an exemplary access authentication process implemented by either the processor of FIG. 2 , or the local processor, the remote processor and/or the server of FIG. 3 , for authenticating the encrypted code transmitted by the badge according to the process of FIG. 4 ; and
FIG. 6 is a high level functional block diagram of an exemplary badge Bn shown in communication with a third party receiver and the receiver module of limited tracking system of FIGS. 2 and 3 .
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 depicts a plurality of badges, cards, persons B 1 –Bn, hereinafter referred to collectively as either “user(s)” or badge(s)”, each provided with a component of a limited tracking system 10 of the present invention, and shown in communication with a base receiver 20 , a processor 30 , and a server 40 , for time-limited access authentication according to the present invention. It will be understood that numerous other environments may also employ the limited tracking system 10 . Such other environments may include, for example, public telephones that accept calling card calls, gas pumps at service stations, photocopy machines, postal meters, and entry through building or automobile doors. Also, the limited tracking system 10 may be used in connection with the computer or processor 30 as a log-in mechanism. In addition, while only one base receiver 20 , processor 30 , and server 40 are shown for illustration purpose only, it should be clear that additional base receivers 20 , processors 30 , and/or servers 40 may be used for a decentralized limited tracking system 10 .
In operation, each badge B 1 –Bn generates a temporal sequence of values, encrypts the temporal sequence with a private key associated with the individual badge B 1 –Bn, and transmits at a predetermined transmission cycle an encrypted code element, for example one every ten seconds In a preferred embodiment a time keeper provides the temporal sequence of values. The resulting encrypted code element, appears to the observer as a random number. As an alternative, the encryption and transmission can be initiated by mechanical means, such as a electrical switch on the badge, or a motion detector. For example, each time the switch is pressed, an encrypted code element is calculated and transmitted. As one (or more) badge B 1 –Bn enters a communication zone 50 , denoted by a circle in dashed line, associated with the base receiver 20 , the encrypted code for that badge is transmitted to the base receiver 20 over a communication link 60 . The transmission can be any wireless means, including infrared, radio frequency, electric field, magnetic field, ultrasonic, and so forth. The transmission can also be by contact, such as a smart card, or by physical contact as described, for example, in U.S. Pat. No. 5,796,827 to Coppersmith et al, which is incorporated herein by reference. Alternatively, at least a part of the transmission link 60 is wireless. The limited tracking system 10 is capable of individually tracking a large number of badges B 1 –Bn that are distributed about a tracking environment or communication zone 50 .
In accordance with the present invention, the communication between the badges B 1 –Bn and the base receiver 20 is encrypted to establish authentication and security. A preferred technique of encryption is described in detail below. Also, if the user carries multiple badges (i.e., transmitters), such as instrumentalities embedded in cards, a watch, or shoes, these badges may be detected separately for authentication.
In accordance with the present invention, and as illustrated in FIG. 1 , a badge Bn transmitter and a base receiver 20 work in combination to provide unidirectional communication. For bidirectional communication, the badge Bn can be provided with a receiver, and the processor 30 can be provided with a receiver. For a unidirectional badge Bn, time is the challenge, and time encrypted by the private key is the response. For a bi-directional communication, the base receiver 20 includes a transmitter which transmits a challenge to the badge Bn. The badge Bn encrypts the challenge by the private key and transmits the response to the base receiver 20 .
FIGS. 2 and 3 are block diagrams of two preferred embodiments of the limited tracking system 10 of the present invention. Unidirectional communication takes place between a badge Bn, and a receiver module 100 that forms part of the base receiver 20 . The limited tracking system 10 supports a scenario in which the badge Bn continuously, or at regular intervals such as every ten seconds, transmits an encrypted code as described herein.
The badge Bn generally includes an encryptor 111 that generates an encrypted code based on a private key (or a user ID) dedicated to the badge Bn and a time representation. The resultant encrypted code can optionally be modulated using a modulator, known to the art of digital communication, such as amplitude modulation, frequency modulation, and spread spectrum (not shown) and transmitted to the receiver module 100 by means of a transmitter unit 120 .
The receiver module 100 is coupled to the communication link 60 for receiving the encrypted code. To this end, the receiver module 100 includes a receiver unit 130 that receives the encrypted code and optionally demodulates it. The received encrypted code is then passed to the server 40 . The server 40 includes an authenticator 140 that authenticates the signal as described in detail below, and provides the information to an application such as a program for confirming the presence of the badge Bn.
The server 40 uniquely identifies the user or the badge Bn, rejecting attempts at impersonation. A sample application would be a unique ID card for a population of several hundred (i.e., 500 ) employees working in a building, each of whom using a badge for access to the building and/or other services.
With reference to FIG. 3 , each user or badge Bn has a unique private key or ID Xn (also reference by the numeral 200 ), represented by a bit-string, typically of length 56 or 128 bits. At ten-second intervals as measured by a clock crystal 210 , the badge Bn transmits a signal f(X,t) (represented as a bit-string), where f( ) is an encryption function which is computed by the encryptor 111 , Xn is the user's unique private key, and t is the time (in seconds) measured, for example, from an initial synchronized starting point of the badge Bn.
According to another embodiment, a network of base receivers 20 can be dispersed in a geographic area to track the whereabouts of the badges B 1 –Bn.
When the badge Bn enters the communication zone 50 , the limited tracking system 10 attempts to discover the identity of the Bn. The receiver unit 130 ( FIG. 2 ) receives the encrypted code, and sends the encrypted code to the server 40 . In turn, the server 40 sends the encrypted code to the authenticator 140 . The authenticator 140 creates an authentication table composed of pre-calculated encryptions for every expected badge Bn for the current time. Upon receiving an encrypted code, the authenticator 140 attempts to find the encrypted code in the authentication table. In a preferred embodiment, an identification number, private key Xn, and offset time value (to be described later) of every badge Bn is stored in a database 260 . The authenticator 140 checks whether or not the decrypted signal matches authenticating codes that are stored in the database 260 of the server 40 , for this particular badge Bn, during a specified time window, that generally corresponds to the badge's entry into the communication zone 50 . If the encrypted code is in the authentication table, the authenticator 140 sends the badge Bn identification number back to the server 40 , else it sends a “not found” message to the server 40 .
It should be noted that the signal or code transmitted by the badge Bn, includes the badge's time encrypted by the private key Xn, but does not include a public ID as was taught by conventional tracking systems. As a result, the encrypted code transmitted by the badge Bn can only be decrypted by a private, non-public key which is available only to the server 40 and to the badge Bn.
Time increments, and the encryption of time, produce a random sequence of numbers that are transmitted. Because the badge Bn sends out what appears to be random numbers, an eavesdropper would see gibberish (random numbers) which would not reveal any information about the carrier of the badge Bn. It is only when these numbers are sent to the authenticator 140 that they are linked with a service, such as an ATM, drivers license, calling card, etc. Detecting the transmission of the badge Bn does not reveal the identity of the user, nor can a relation be made between a current transmission and previous ones, without knowledge of the private key. In this way, anonymousity of the user is maintained.
Referring to FIG. 3 , the badge Bn contains a clock 210 , private key Xn 200 , encryptor 111 , and wireless transmitter 120 . The clock 210 provides the current time, and includes a time reference, preferably a quartz crystal oscillating at 31.768 kHz. In a preferred embodiment, the current time is the elapsed time in seconds since the badge Bn was manufactured. The encryptor 111 in the badge Bn uses an encryption that can be, for example, the well-known Data Encryption Standard (DES). The encryptor 111 periodically encrypts time (t) with the private key Xn 200 , and transmits the result using the transmitter 120 .
Referring to the flow chart of FIG. 4 , it illustrates an exemplary encryption and transmission method 400 implemented by the badge Bn according to the present invention. The method 400 starts at step 410 and inquires at decision step 420 if a predetermined period of time (i.e. the predetermined transmission cycle), such as 10 seconds, has elapsed since the last transmission by the badge Bn. If the elapsed time still has not exceeded the predetermined period, the method 400 returns to decision step 420 and repeats the inquiry until the elapsed time exceeds the set time period. At which stage, the method 400 proceeds to step 430 where it resets the elapsed time interval.
The method 400 then proceeds to step 440 where the DES encryptor 111 of FIG. 3 encrypts the time for the badge Bn by the user's private key Xn, as can be represented by the following expression:
f ( Xn,t )=( T Bn ) Kn ,
where (T Bn ) represents the time for the badge, Kn represents the private Key for the badge Bn, and where n varies in the above example from 1 badge to 500 badges.
At step 450 the transmitter unit 120 transmits the encrypted code (T Bn ) Kn to the receiver module 100 and the server 40 , and then returns to decision step 420 for repeating steps 430 – 450 . As it will be described in connection with FIG. 5 , the receiver module 100 and the server 40 receive and authenticate the encrypted code (T Bn ) Kn . The server 40 then looks up the private key Xn that has generated the encrypted code (T Bn ) Kn , and from this private key Xn, the server 40 identifies the badge Bn. In one implementation, the badge Bn requires about 96 bits of RAM to implement the DES encryption, another 64 bits for the time tn, and a few thousand bits of ROM for the DES encryption. Faster implementations of DES would require for example approximately 32K bits of ROM.
Referring now to FIG. 5 , it illustrates an exemplary access authentication method 500 which is implemented by either the processor 30 of FIG. 2 for authenticating the encrypted code (T Bn ) Kn transmitted by the badge Bn. The authentication method 500 starts at step 510 and inquires at decision step 420 if a predetermined period of time, such as 1 second, has elapsed since the last reception cycle. In a preferred embodiment the temporal resolution of the authentication table, determined by the period at step 520 of FIG. 5 should be equal to, or greater than the predetermined transmission cycle 420 of FIG. 4 , so the authenticator 140 has equal or greater temporal resolution than the badges Bn.
If the authentication method 500 determines at the decision step 520 that the elapsed time still has not exceeded the predetermined period, the method 500 determines at decision step 525 if a valid badge packet has been received. To this end, the packet transmitted by the badge Bn typically includes three fields: a preamble field, a payload field, and a checksum field.
The preamble contains data bits indicating that the packet is originating from a valid badge, or otherwise a badge associated with the limited tracking system 10 . This precautionary measure allows the limited tracking system 10 to filter out transmissions, noise, or otherwise irrelevant signals, and to process only related signals. The payload field contains the encrypted code (T Bn ) Kn described earlier, which will eventually be processed by the receiver module 100 for badge authentication. The checksum field provides means for checking the integrity of the transmission.
If the authentication method 500 determines at the decision step 525 that the received packet is not a valid badge packet, by for example analyzing the preamble field content or the checksum is not correct, the method 500 ignores the packet and returns to the decision step 520 , where it repeats the inquiry until the elapsed time exceeds the set time period.
At this stage, the method 500 proceeds to step 530 where the elapsed time count is reset. The method 500 then proceeds to step 540 and encrypts the sum of the current time badge Bn time (T Bn ) and offset time value (T on ) with respect to the private key Xn for all the valid the badges B 1 –Bn, as represented by the following expression:
En =( T Bn +T on ) Kn ,
where T on is the offset time or time drift for each badge Bn which will be explained in the next paragraphs, En is the encrypted result for badge n, T Bn is the time for badge n, Kn is the key for badge n, and T on is the time drift for badge n. Initially, Ton is set to zero the first time it is detected, and is modified based on successive authentications of the badge Bn.
Since the badge Bn does not transmit the time, the current time badge Bn time (T Bn ) is calculated by the authenticator 140 by the following expression;
( T Bn )= T system −T badge n creation
where T system is the current server 40 system time in seconds and T badge n creation is the time the badge Bn was created, referenced to the same time standard as T system . The T badge n creation for each badge Bn is stored on the database 260 .
One problem addressed by the present invention is time drift that develops between the badge Bn and the authenticator 140 . There are generally two main causes for the time drift: (a) systematic, the time reference of a particular badge Bn is faster or slower than the authenticator 140 ; and (b) random, the time reference of a particular badge Bn usually varies due to temperature or other environmental changes.
The first cause is predictable, and in a preferred embodiment the authenticator 140 calculates the frequency of each badge B 1 –Bn from successive authentications. Time drifts due to temperature changes are usually minimal, since the badge Bn is typically kept with a person at room temperature. The stability of practical time references are demonstrated by the time keeping ability of inexpensive digital watches that can maintain time to within a few minutes per year.
Another feature of the present invention is the establishment of a window of tolerance (also referred to as a clock synchronization window, drift window, or temporal tolerance window) for the encrypted result, En, in order to allow authentication in the presence of time drift. Since the clocks 210 ( FIG. 3 ) of the badges B 1 –Bn and the clock at the server 40 cannot be expected to remain in perfect synchrony, the server 40 allows a clock synchronization window within which authentication would proceed.
According to one embodiment, the server 40 allows authentication within a “drift window” centered around the time T Bn of the badge Bn, as shown by the following expressions:
En 1=( T Bn +T on ) Kn ,
En 2=( T Bn +T on −Epsilon) Kn , and
En 3=( T Bn +T on +Epsilon) Kn ,
where Epsilon is the transmission cycle.
In this embodiment, En1 is the encrypted results when the badge Bn is in synchrony with the server 40 (to within +/− one half of a transmission cycle). En2 is the encrypted results when the badge Bn lags the server 40 by one transmission cycle (+/− on half a transmission cycle). En3 is the encrypted results when the badge Bn leads the server 40 by one transmission cycle (+/− on half a transmission cycle). In this example, the drift window is 2 transmission cycles, that is the badge Bn can lead or lag the server 40 by one transmission cycle. In this example, and in the preferred embodiment, the temporal resolution (increment size) of the temporal sequence of values generated in the badge Bn is equal to the transmission cycle.
As stated earlier, the intially T on is set to zero on the first read of the Badge Bn by the server 40 , and is modified based on successive authentications of the badge Bn. If the badge Bn authenticates with E1, T on remains the same. If the badge Bn authenticates with E2, T on is decremented (T on =T on −1). If the badge Bn authenticates with E3, T on is incremented (T on =T on +1). By this method, the authenticator 140 tracks drift in the badge Bn clock 210 , preventing the drift from accumulating and preventing authentication. A more sophisticated method of correcting for drift is to observe the drift over time, calculate the slope of drift, store the slope for each badge Bn, and calculate T on based on the slope of drift. This would compensate for systematic drift in the badge, i.e. the time reference of a particular badge Bn is faster or slower than the authenticator 140 ;
A typical exemplary value for the synchronization window can be approximately 20 seconds. This function is implemented by a synchronizer 285 at the server 40 ( FIG. 2 ).
Upon completion of the encryption of step 540 , the authentication method 500 proceeds to decision step 525 and checks the validity of the received packet as explained earlier. If at step 525 it is determined that the received packet has originated from a valid badge Bn, it proceeds to step 550 where it looks up the received encrypted code (T Bn ) Kn in the server database 260 .
The server 40 then inquires at step 560 whether the encrypted code (T Bn ) Kn is found in the database 260 . If the encrypted code (T Bn ) Kn is not found, the server 40 generates an alarm, whether visual or audible, advising the badge user of the procedure to follow to have the situation corrected. For example, the server 40 can advise the badge user to proceed to the security office to have the badge clock 210 resynchronized, by changing the badge's Ton entry in the database 260 , or to provide permission to the service or access requested.
If, on the other hand, the encrypted code (T Bn ) Kn is located in the database 260 , the server 40 authenticates and identifies the badge Bn at step 580 . Once the badge Bn is authenticated, the server 40 can execute an application at step 590 , or alternatively, it can instruct the local processor 240 ( FIG. 3 ) to execute the application. Exemplary applications include: allowing access to the building, logging on to a network, gaining access to a car, or dangerous piece of equipment like a medical machine that administers radiation, hydraulic pressing for stamping car doors, medical cabinets for dispensing narcotics, registers for dispensing cash, guns for shooting bullets, and so forth.
FIG. 6 describes a specific implementation of the limited tracking system 10 . Either the processor 30 ( FIG. 1 ) or the secure server 40 stores the private keys Kn of all the badges B 1 –Bn. The private keys Kn are not available to the third party as represented by block 252 .
The user of the badge, e.g. badge Bn, can give the third party, also referred to herein as finder, access to the user's encrypted codes for specified time periods. To this end, the badge (Bn) user, using the processor 30 ( FIG. 1 ) instructs the server 40 to deliver a list of encrypted codes, i.e., a list of the times encrypted with the user's private key, for specific time periods, to the third party's local processor 275 .
The code list can be transmitted or otherwise provided to the finder, i.e., local processor 275 for storage on the local processor 275 for local autonomous authentication, or to the finder's own server 340 and database 360 for networked authentication. When the third party receiver 252 detects a transmission from the user's badge Bn, the third party receiver 252 sends the encrypted code to the local processor 275 . If authentication is to take place locally, local processor 275 compares the encrypted code it received from the badge Bn to the code list stored in its internal memory (for example hard drive) indexed by the current time. The local processor 275 can keep time using an internal clock, or externally receive accurate time, for example from a trusted site on the internet. If a match exists, the third party local processor 275 confirms the detection of the user's (or badge Bn) location, for example giving the user access to the resources of local processor 252 , including data and applications on the local hard drive.
In the example of networked authentication, the local processor 275 receives the encrypted code from the third party receiver 252 and sends it to the server 340 . The server compares the encrypted code to the code list indexed by time. If a match exists, the server 340 sends a message confirming the detection of the badge Bn to the local processor 275 . If no match exists, the server 340 sends a denying message to the server 340 , that for example will prevent access to local processor 275 resources.
A more specific example of the use of the limited tracking system 10 of FIG. 6 is as follows: A user provides the local processor 275 with a list of encrypted codes that reflects the time periods during which tracking would be allowed, for example, from 12:00 PM to 1:30 PM weekdays. At 12:00:00 PM on Tuesday, the user's badge Bn transmits the code 3948573, while within the communication zone 50 , and at 12:00:10 PM it transmits the code 93874832. The badge Bn continues to transmit updated encrypted codes periodically. The code list provided to the local processor 275 contains only valid entries or codes (i.e., 3948573, 93874832, etc.) for the time periods the user has specified, to grant selective and limited access, at these particular times, and not complete access independent of time.
It is to be understood that the specific embodiments that have been described herein are merely illustrative of certain applications of the principle of the present invention. Numerous modifications may be made without departing from the spirit and scope of the present invention. | A limited tracking system and associated method that enable the use of personal encoded identification media to limit access to tracking information. The tracking system provides concurrent time-limited access to a large number of people, objects, information, services, and other resources, and has particular applicability to credit cards, dining cards, telephone calling cards, health cards, driver's licenses, video store cards, car access cards, building access cards, computer access cards, and like identification badges or cards. The tracking system includes a transmitter module incorporated in a badge, and a receiver module incorporated in a secure server. The transmitter module contains an encryptor and a watch crystal that keeps track of time, such that the encryptor encrypts the current time with the user's private key, and periodically transmits the encrypted current time to the receiver module, as a code list. The server stores the private keys of all the users, and, in turn, encrypts the current times of all the badges with the corresponding private keys of the users, to generate an authentication table. An authenticator compares the received code list to the authentication table, seeking matches that are indicative of the validity of the transmitting badges. | 7 |
FIELD OF THE INVENTION
The present invention relates to a novel process for the synthesis of organohaloboranes and alkoxyorganoboranes, and especially to the synthesis of diorganomonohaloboranes and organodihaloboranes.
BACKGROUND OF THE INVENTION
Chloroborane complexes, the precursors to organohaloboranes, have been prepared by a variety of methods. See H. C. Brown, S. U. Kulkarni, J. Organomet. Chem. 1982, 239, 23-41. For example, lithium or sodium borohydride and boron trichloride give chloroborane-ether adduct according to the following reaction: ##STR1## where M=Na, Li. See H. C. Brown, P. A. Tierney, J. Am. Chem. Soc. 1958, 80, 1552; H. Noth, H. Beyer, Ber. 1960, 93, 225; U.S. Pat. No. 3,026,329.
A mixture of borane-tetrahydrofuran adduct and boron trichloride form chloroborane-tetrahydrofuran adduct according to the following reaction: ##STR2## See D. J. Pasto and P. Balasubramaniyan, J. Am. Chem. Soc. 1967, 89, 295; D. J. Pasto and S. Kang, J. Am. Chem. Soc. 1968, 90, 3797.
Borane-dimethylsulfide adduct (DMSB) and dimethylsulfide boron trichloride give dimethylsulfide chloroborane according to the following reaction:
2Me.sub.2 S·BH.sub.3 +Me.sub.2 S·BCl.sub.3 →H.sub.2 BCl.Me.sub.2 S
See K. Kinberger and W. Siebert, Z. Naturforsch., B 1975, 30, 55; H. C. Brown and D. Ravindran, J. Org. Chem. 1977, 42, 2533; H. C. Brown, Inorg. Chem. 1977, 16, 2938. These chloroborane ether and sulfide adducts have been used in hydroboration reactions as described in detail below.
Finally, gas phase reaction of diborane and boron trichloride gives dichloroborane according to the following reactions:
B.sub.2 H.sub.6 +4BCl.sub.3 →6BCl.sub.2
2BCl.sub.3 +5B.sub.2 H.sub.6 →6B.sub.2 H.sub.5 Cl
See J. Cueilleron, J. Bonix, Bull. Soc. Chim., France 1967, 2945. Although these gas phase reactions were not conducted for subsequent hydroboration reactions, they demonstrate that chloroboranes can be prepared in the absence of coordinating ether or sulfide ligands.
Diisopinocampheylchloroborane (hereafter referred to as DPC) is a very useful chiral reducing agent for prochiral ketones and imines. DPC can be prepared from α-pinene and chloroborane diethyl etherate. H. C.Brown, P. K. Jadhav. J. Am. Chem. Soc. 1983, 105, 2092. A variation of this process using dimethyl sulfide chloroborane has been elaborated by G. Bir and A. O. King. G. Bir, D. Kaufmann, Tetr. Letters 1987, 28, 777; and A. O. King et al., J. Org. Chem. 1993, 58, 3731-3735.
Brown purports to obtain high optical purity DPC through a two-step procedure. See U.S. Pat. Nos. 4,772,752 and 5,043,479. In this procedure, diisopinocampheylborane, a moisture and thermally sensitive intermediate is isolated from the reaction of α-pinene and DMSB. Subsequent addition of hydrogen chloride gives the final product, DPC, as a moisture sensitive solid, which is isolated from the solution. On an industrial scale this complicated process presents several technical difficulties including the handling of thermally-sensitive solids as well as the handling of moisture sensitive product.
A. S. Thompson, in J. Org. Chem. 1992, 57, 7044-7052, and A. O. King, supra, have shown that solutions of DPC made from >70% ee α-pinene and DMSB or dimethyl sulfide chloroborane can be used in excess to achieve high optical purity reduction products, without the need for the handling of the moisture sensitive DPC solid.
All of these processes for making DPC involve use of chloroborane-diethyl ether adduct, which is thermally unstable, or dimethyl sulfide chloroborane adduct, which is notoriously malodorous. Some of the ether and sulfide ligands cause problems in the formation and use of the organochloroboranes. For example, diorganochloroborane formed from a haloborane-tetrahydrofuran adduct can cleave tetrahydrofuran rendering the borane compound unusable. Furthermore, the sulfide adducts leave a sulfur smell on the final product. Development of a method for hydroboration of α-pinene by chloroborane to form DPC without the use of ether chloroborane adduct or sulfide chloroborane adduct is, therefore, very desirable.
SUMMARY OF THE INVENTION
Accordingly, the present invention provides a process for the generation of diorganohaloboranes and organodihaloboranes without the use of ether chloroborane adduct or sulfide chloroborane adduct. Diorganohaloboranes are useful precursors to borinic acids and esters by methods known in the art. See D. S. Matteson et al., Organometallics 1984, 7, 1284-1288; H. C. Brown ibid. 1983, 2, 1311-1316; ibid. 1986, 5, 994-997. Organodihaloboranes are precursors to boronic acids and esters See H. C. Brown, Organometallics 1982, 1,212.
Generally, the present invention provides a novel process for the preparation of organohaloboranes of the formula, R 2 R 3 BX (a diorganohaloborane) and RBX 2 (an organodihaloborane), comprising the step of reacting in a single reactor an olefin(s) and/or alkyne(s) with boron trihalide and diborane according to the following general reactions:
3R+3R.sup.1 +B.sub.2 H.sub.6 +BX.sub.3 →3R.sup.2 R.sup.3 BX
6R+B.sub.2 H.sub.6 +4BX.sub.3 →6R.sup.2 BX.sub.2
wherein X is a fluoro, a chloro, a bromo, or an iodo group, R is an olefin or an alkyne and R 1 is an olefin or an alkyne. R 1 can be the same as or different from R. In the above reactions, if R is an olefin, R 2 is the corresponding alkyl group. If R is an alkyne, R 2 is the corresponding alkenyl group. Likewise, if R 1 is an olefin, R 3 is the corresponding alkyl group. If R 1 is an alkyne, R 3 is the corresponding alkenyl group. In the case of R 2 R 3 BX, R 2 and R 3 can be linked together to form a ring or bicyclic system, such as B-chloro-9-borabicyclo[3.3.1]nonane. The reaction can be run neat or in any solvent compatible with the reagents and product. Examples of suitable solvents for a number of reactions under the present invention include the following hydrocarbon solvents: pentane, hexane, heptane, cyclohexane, methylcyclohexane toluene or benzene.
Moreover, alkoxydiorganoboranes and dialkoxyorganoboranes can be prepared under the above general reactions wherein X is an alkoxy group. In the synthesis of such alkoxyorganoboranes, a dialkylborane (or tetraalkyldiborane) may be added to the reaction mixture as a catalyst.
Olefins for use in the above reactions have the general formula: ##STR3## wherein R 4 , R 5 , R 6 and R 7 are any combination of hydrogen, an aryl group, an aralkyl, a branched alkyl group, an unbranched alkyl group or a cyclic group, such groups containing from one to ten carbon atoms. Alternatively, R 4 and R 5 can be linked by a C n chain wherein n=2-10 or R 4 and R 6 are linked by a C n chain wherein n=2-10. The aryl and alkyl groups may comprise functionalities such as ester groups, ether groups, halo groups, silyl groups or nitro groups. The olefin group may also be a terpene from a naturally derived source.
Alkynes for use in the present reaction have the general formula: ##STR4## wherein R 8 and R 9 are any combination of hydrogen, an aryl group, an aralkyl group, a branched alkyl group, an unbranched alkyl group or a cyclic group, such groups containing from one to ten carbon atoms. Alternatively, R 8 and R 9 can be linked by a C n chain where n=8-15. The aryl and alkyl groups may comprise functionalities such as ester groups, ether groups, halo groups, silyl groups or nitro groups.
The present single reactor or "one-pot" process eliminates the need for coordinating ligands such as ethers or sulfides. The process generates substantially no waste by-products and can easily be run on a large scale.
Particularly useful compounds for preparation using the present process are DPC, diisocampheylchloroborane and dicyclohexylchloroborane. Dicyclohexylchloroborane is useful for the preparation of boron enolates.
DETAILED DESCRIPTION OF THE INVENTION
As used in connection with the present invention, the term "alkyl" means a branched, an unbranched, or a cyclic saturated hydrocarbon group containing one to twenty carbon atoms; the term "aralkyl" means an ω-aryl-alkyl group, wherein the aryl group may be a phenyl group, a substituted phenyl group or any other aromatic ring system; the terms "halo" or "halide" mean a fluoro, a chloro, a bromo, or an iodo group; the term "alkyne" means a compound containing a carbon-carbon triple bond; the term "olefin" means a compound containing a carbon-carbon double bond; "enantiomeric excess" (or e.e.), is defined as the excess of one of a pair of enantiomers, usually expressed as a percentage derived from the formula: [(R-S)/(R+S)]×100; the term "prochiral" describes an sp 2 hybridized atom which upon conversion to sp 3 hybridization yields a chiral center at that atom.
Preparation of Diorganohaloboranes and Alkoxydiomanoboranes
Under the present invention diorganohaloboranes are synthesized by reacting an olefin and/or alkyne (neat or in a suitable solvent) with boron trihalide and diborane. In this reaction, the mole ratio of olefin/alkyne to boron trihalide is in the range of approximately 4:1 to 10:1 and preferably in the range of approximately 6:1 and 9:1. The ratio of boron trihalide to diborane is in the range of approximately 1:1.5 and 1.5:1 and preferably in the range of approximately 1:1 and 1:1.5. The resulting reaction mixture is agitated at a temperature between about -20° C. and the reflux temperature of the system, preferably between ambient temperature and the reflux temperature of the system under an inert atmosphere (e.g., nitrogen, argon, etc.) at ambient or moderately superambient pressure, e.g. 1 to 10 bar, until the reaction is complete, typically for a time between 1 and 72 hours. The reflux temperature of the system is generally the boiling point of the solvent at the pressure of the reaction. The resulting diorganohaloborane may be used " as is" in solution or isolated from the solvent. For example, DPC can be crystallized and isolated as a solid with enhanced optical purity. Certain diorganohaloboranes may precipitate from the hydrocarbon solvent and can be easily filtered.
Alkoxydiorganoboranes can be prepared under the above synthetic scheme by substituting an alkyl borate of the general formula B(OR 10 ) 3 , wherein R 10 is an alkyl group, for the boron trihalide reactant. Preferably, R 10 is a methyl, an ethyl or an isopropyl group.
Preparation of Oroanodihaloboranes and Dialkoxyorganoboranes
Likewise, organodihaloboranes are synthesized under the present invention by reacting an olefin or alkyne (neat or in a suitable solvent) with boron trihalide and diborane. The mole ratio of olefin or alkyne to boron trihalide is typically in the range of approximately 1:1 and 2:1 and preferably 3:2. The ratio of boron trihalide to diborane is in the range of approximately 3:1 and 5:1 and preferably 4:1. The resulting reaction mixture is agitated at a temperature between about -20° C. and the reflux temperature of the system, preferably between ambient temperature and the reflux temperature of the system under an inert atmosphere (e.g. nitrogen, argon, etc.) at ambient or moderately superambient pressure, e.g. 1 to 10 bar, until the reaction is complete, typically for a time between 1 and 72 hours. The reflux temperature of the system is generally the boiling point of the solvent at the pressure of the reaction. The resulting organodihaloborane may be used as a solution or isolated from the solvent.
Dialkoxyorganoboranes can be prepared under the above synthetic scheme by substituting an alkyl borate of the general formula B(OR 10 ) 3 , wherein R 10 is an alkyl group, for the boron trihalide reactant. Preferably, R 10 is a methyl, an ethyl or an isopropyl group.
EXAMPLES
General Procedures
All experiments were conducted under nitrogen in glass or stainless steel pressure vessels equipped with either magnetic or mechanical stirring. The pressure vessels were equipped with back-pressure regulators set to release excess pressure to a methanol or aqueous NaOH scrubber.
1 H NMR spectra were recorded in deuterochloroform on a Bruker-250 NMR spectrometer and reported in ppm relative to an internal standard of tetramethylsilane (as 0.0 ppm). 11 B NMR spectra were taken of reaction solutions or in an appropriate non-reactive solvent on a Bruker-250 NMR spectrometer at 80.25 MHz and reported in ppm relative to BF 3 ·Et 2 O (0.0 ppm) external standard. Specific rotations were determined on a JASCO DIP-370 with sodium lamp at the D line, 589 nm. Concentrations (c) for specific rotations are reported in units of g/100 mL.
Analytical gas chromatography (GC) was carried out on a Hewlett-Packard 5890A gas chromatograph with split-mode injector, flame-ionization detector and helium as the carrier gas. A chiral capillary column (30 m×0.20 mm), Cyclodex-B (J & W Associates), was used to determine optical and chemical purity of α-pinene and oxidation products of DPC.
As necessary, solvents were dried over 4A molecular sieves. Residual water content was determined by Karl Fisher titration. (+)-α-Pinene (Aldrich) was 87% ee as determined by optical rotation and chiral GC. (-)-α-Pinene (Glidco) was 80% ee.
The following examples illustrate the present invention without limitation of the same. The compounds prepared in the examples gave satisfactory boron and chloride analyses.
Example 1
(-)α-Pinene (958 g. 7.03 mol) (i.e., R=R 1 =(-)α-Pinene) and hexane (198.4 g) were loaded into a dry nitrogen-filled, stainless steel pressure reactor. Boron trichloride (118 g. 1.01 mol) was added to the α-pinene/hexane solution. A back-pressure relief valve was set at 2 bar. The mixture was stirred while diborane (31 g, 1.1 mol) was added over 150 min. No temperature increase was observed. The solution was heated to 55°-60° C. for 5 h, then allowed to stand at ambient temperature until conversion was completed. The solution was monitored by 11 B NMR to determine reaction progress. Yield: 1305 g (76.8 wt % (+) DPC in hexane) (i.e., R 2 =R 3 =isopinocampheyl group). 1 H NMR (CDCl 3 ). 1.0-1.3 (m, 4H), 1,04 (d, 6H), 1.05 (s, 6H), 1.19 (s, 6H), 1.64-2.07 (m, 8H), 2.29 (m, 2H), 2.50 (m, 2H). 11 B NMR (hexane) δ76. Boron Analysis of the Solution: 76.8 wt %. Optical Purity Analysis by Chiral GC: 84% ee.
Example 2
(-)-oc-pinene (1,458 g, 10.70 mol) and toluene (184 g) was loaded into a 1 gallon stainless steel pressure vessel. Boron trichloride (179.5 g, 1.532 mol) was added, followed by diborane (50 g, 1.8 mol). The reaction mixture was then heated to 60° C. for 4 h. The reaction was shown to be complete by 11 B NMR after 4h. After cooling to ambient temperature, the reaction mixture was transferred to glass bottles. Yield: 1,759 g of 83 wt % (+)-DPC in toluene.
11 B NMR (Toluene) δ74 Boron Analysis of the Solution: 83 wt % Density: 0.962 g/mL at 20° C. Optical Purity Analysis by Chiral GC of Oxidized Product: 88.6% ee (+) DPC
Example 3
Cyclohexene (173.5 g, 2.112 mol) and 100 ml of hexane were loaded into a dry nitrogen-filled glass pressure reactor. Boron trichloride (38 g, 0.33 mol) was added to the cyclohexene/hexane mixture. A back-pressure relief valve was set at 3.1 bar. The mixture was stirred while diborane (9 g, 0.3 mol) was added over 80 min. No temperature increase was observed. The solution was heated to 55-60° C. for 10.5 h, until conversion was complete. The 11 B NMR spectrum showed 93.5% dicyclohexylchloroborane. 11 B NMR (hexane) δ76.5.
Example 4
1-Hexene (224 g, 2.66 mol) and 100 mL of hexane were loaded into a dry nitrogen-filled glass pressure reactor. Boron trichloride (44 g, 0.38 mol) was added to the 1 -hexene/hexane mixture. A back-pressure relief valve was set at 3.1 bar. The mixture was stirred while diborane (12 g, 0.43 mol) was added over 60 min. The solution was heated to 84° C. for 24.5 h until conversion was complete. The 11 B NMR spectrum showed 95% dihexyl chloroborane. 11 B NMR (hexane) δ78.
Example 5
Boron trichloride (14.6 g, 0.125 mol) was added to 100 mL of hexane in a dry nitrogen-filled glass pressure reactor. 1-Hexyne (68.5 g, 0.834 mol) and 100 mL of hexane were added to the BCl 3 . The mixture was stirred while diborane (3.5 g, 0.13 mol) was added over 30 min. The solution was heated to 60° C. and maintained for 4.5 h until 95% conversion to dihexenylchloroborane. 11 B NMR (hexane) δ73.
Example 6
Boron trichloride (14.7 g, 0.127 mol) was added to 200 mL of hexane in a dry nitrogen-filled glass pressure reactor. 1,5-Cyclooctadiene (48.1 g, 0.445 mol) was added to the BCl 3 solution. The mixture was stirred while diborane (4.0 g, 0.14 mol) was added over 20 min. The solution was heated for 10 h at a temperature between 65°-85° C. 11 Boron NMR analysis showed 93% conversion to B-chloro-9-borabicyclo[3.3.1]nonane. 11 B NMR (hexane),δ82.
Example 7
(+)-α-pinene (100.0 g, 0.734 mol) and hexane (200 ml) were loaded into a dry nitrogen-filled, glass pressure reactor. Boron trichloride (55.3 g, 0.472 mol) was added, followed by diborane (4.0 g, 0.14 mol). The reaction mixture was then heated to 40° to 60° C. for 4 days. 11 Boron NMR spectra of the reaction mixture showed 91% isopinocampheyldichloroborane at δ63.
Example 8
Cyclohexene (61.2 g, 0.745 mol) and hexane (200 ml) were loaded into a nitrogen-filled glass pressure reactor. Boron trichloride (59.9 g, 0.511 mol) was added. The back-pressure regulator was set to 2 bar. Diborane (50 g, 0.18 mol) was added. The reaction mixture was heated to 50°-60° C. for 5 days. The reaction was monitored by 11 Boron NMR and shown to contain 86% cyclohexyl dichloroborane δ3 64.
Example 9
(+)-α-pinene (271 g, 1.98 mol) and hexane (100 ml) were loaded into a dry nitrogen-filled, glass pressure reactor. Methyl borate (29.0 g, 0.28 mol) was loaded to the α-pinene/hexane solution. A back-pressure relief valve was set at 2 bar. The mixture was stirred while diborane (7.8 g, 0.28 mol) was added over 30 minutes. The reaction was exothermic during the diborane addition. The reaction mixture was then heated to 40° C. for 5 hours. 11 Boron NMR analysis of the product showed 96% conversion to (-)diisopinocampheylmethoxyborane, 2% (-)isopinocampheyldimethoxyborane and 2% unreacted methylborate. 11 Boron NMR (hexane) δ53. Boron analysis of the solution: 76%.
Example 10
Tetraethyldiborane (62.5 g, 0.447 mol) was loaded into the glass pressure vessel as a catalyst. The back-pressure regulator was set to 2 bar. Diborane (5.0 g, 0.149 mol) was added followed by methylborate (62.0 g, 0.596 mol) Ethylene (50 g, 1.8 mol) was bubbled into the solution over 4.5 hours. The reaction was exothermic and was kept between 20°-35° C. with a refrigerated bath. When ethylene uptake ceased the reaction mixture contained 61% methoxydiethylborane, 27% trimethylborane and 10% dimethoxyethylborane as determined by 11 Boron NMR.
Although the present invention has been described in detail in connection with the above examples, it is to be understood that such detail is solely for that purpose and that variations can be made therein by those skilled in the art without departing from the spirit and scope of the invention except as it may be limited by the following claims. | A one-step process is provided for the synthesis of organohaloboranes, including diisopinocampheylchloroborane, and alkoxyorganoboranes. The present process does not utilize a thermally unstable ether adduct or a malodorous dimethyl sulfide adduct as required in prior processes. In general, the organohaloboranes are synthesized in a single reactor by reacting olefin(s) and/or alkyne(s) with boron trihalide and diborane. Alkoxyorganoboranes are synthesized in a single reactor by reacting olefin(s) and/or alkyne(s) with alkylborate and diborane. | 2 |
This is a division of application Ser. No. 438,813, filed Nov. 3, 1982, now U.S. Pat. No. 4,510,115.
FIELD OF THE INVENTION
This invention relates generally to blow molding and it particularly relates to blow molding of novel, layered, hollow thermoplastic containers. The method involves initially forming a layered thermoplastic parison, followed by blow molding the parison in a mold cavity to form the desired configuration of hollow article. The blow molded articles can be of any configuration achievable with known blow molding technology. Every section of the article can be layered, or the article can have selectively intermittent layered sections. The containers typically are used for storing and dispensing liquids and are of one piece construction.
BACKGROUND OF THE INVENTION
Hollow, blow molded, thermoplastic articles enjoy widespread commercial acceptance because of ease of fabrication and reduced labor costs. Abundant applications for blow molded, thermoplastic articles are apparent in the medical field alone. Form, fill, and seal blow molded containers, designed for sterile and aseptic packaging of parenteral solutions and the like, are well known.
In certain applications, however, additional operations need to be performed on blow molded containers to decrease their water vapor permeability, decrease their permeability to gasses (especially oxygen), or provide a sterile surface on at least a portion of the outside of the container as may be desirable, particularly in the medical field. Additional layers of thermoplastic or adhesive material may be applied to blow molded containers in subsequent operations, after the article has been blown, in efforts to decrease permeability or provide a sterile surface. Subsequent operations, though, tend to be time consuming and labor intensive, thus increasing the cost of the completed article. Further still, when sterility is a factor, it is difficult to maintain acceptable control.
Heretofore, thermoplastic containers have had additional layers applied by methods such as dip coating, spray coating, shrink fit coating, or injection overmolding. See, for example, U.S. Pat. No. 3,457,337, Method for Producing Coated Containers, to Turner. Where gas permeability or water vapor permeability is important, outer layers of plastic material may be applied. Where medical uses are contemplated, the exterior of blow molded, thermoplastic containers can be sterilized by overcoating of the outer surface under sterile conditions or before terminal sterilization.
Plastic containers are often blow molded from a continuously extruded tube. Methods of coextrusion exist which comprise simultaneously extruding coaxial tubular members and then blow molding those members. Layered plastic containers are produced thereby, specifically to decrease gas or water vapor permeability of the container. See, for example, U.S. Pat. No. 4,079,850, Multi-Layer Blow Molded Container and Process for Preparation Thereof, to Suzuki, et al. and U.S. Pat. No. 3,457,337, Method for producing coated Containers, to Turner. Typically, though, the container layers are not easily separable or peelable because the thermoplastic materials used have been compatible, that is, they adhere at their interface.
By this invention layered, blow molded thermoplastic containers are produced by simultaneously feeding two thermoplastic materials, using existing injection or extrusion technology, into a blow molding die, extruding the simultaneously fed thermoplastic materials to form a layered parison, and then blow molding the parison.
As an additional feature, blow molded articles are provided which have the advantages of layered sealing systems without the need to provide subsequent, separate operations.
Another additional feature of the present invention is found in the flexibility afforded in locating layered sections. This invention provides a novel method of simultaneously feeding incompatible thermoplastic materials into a blow molding die to produce an optionally intermittently layered parison which is blow molded into an intermittently layered article.
Still another advantage of the present invention lies in the ability to produce a blow molded thermoplastic article with a peelable thermoplastic layer thereover, which is simultaneously blow molded with the article, and which maintains a sterile interface until removed.
Further features of the invention include providing containers with reduced gas permeability or water vapor permeability by blow molding layered, thermoplastic containers.
BRIEF SUMMARY OF THE INVENTION
The present invention provides a method of forming layered, hollow thermoplastic articles. The method involves controlled simultaneous feeding of at least two thermoplastic materials into a blow molding die and thereafter extruding the simultaneously fed thermoplastic materials from the blow molding die to form a layered, thermoplastic parison. Blow molding of the parison in a mold cavity follows, with the result being a hollow article of desired configuration. In accordance with this invention, the thermoplastic materials are of a type which are incompatible. The term incompatible is broadly used to designate thermoplastic materials exhibiting an adhesion bond between the materials which is weak enough to allow separation or peeling of the layers. Incompatible materials are defined as having a bond strength of 6.7 pounds per square inch or less as determined by ASTM Designation: D 952-51 (Reapproved 1961).
Simultaneous feeding of one or more of the thermoplastic materials into the blow molding die can be intermittent with a resulting extruded parison and completed article that is intermittently layered. Normal die programming means can precisely control the position and thickness of the layers of the parison and, hence, the position and thickness of layers on the completed articles. A large variety of articles unique to blow molding may be produced by the method of this invention.
By appropriate selection of incompatible thermoplastic materials, articles having removable or peelable outer layers may be obtained. The ease with which outer layers are removable depends, of course, upon the selection of thermoplastic materials. In addition to easily peelable outer layers, injection sites on medical containers made from thermoplastic elastomers may be made in accordance with this invention. In addition, feeding temperatures of at least about 350° F. for the fed, extruded thermoplastic materials can be used to produce a sterilized interface between layers on the blow molded article.
The blow molded articles of the present invention may be filled with a sterile fluid, for example, water, saline solution, or one of a myriad of other fluids. The filling and sealing of such containers may be done in accordance with known blow molding technology.
Other aims and advantages of this invention will become apparent upon reading the following detailed description and appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
For a more complete understanding of this invention, reference should now be had to the embodiments illustrated in greater detail in the accompanying drawings.
In the drawings:
FIG. 1 is a cross section of an intermittently layered parison in the process of being extruded from a blow molding die.
FIG. 2 is a cross section of a blow molded article in a mold cavity being filled after blowing.
FIG. 3 is a cross section showing the filled article of FIG. 2 as sealing begins.
FIG. 4 is a cross section of the blow molded article of FIG. 2 showing the completed seal.
FIG. 5 is a front elevational view in partial cross section showing the formed, filled, and sealed container.
FIG. 6 is a cross section of a mold cavity accepting a layered parison for blow molding thereof.
FIG. 7 is a cross section of the mold cavity of FIG. 6 in a closed position before blowing.
FIG. 8 is a cross section of the mold cavity of FIG. 6 showing blowing of the parison.
FIG. 9 is a cross section of the mold cavity of FIG. 6 illustrating the filling of a blown container bag and formation of an access port.
FIG. 10 is a cross section of the mold cavity of FIG. 6 showing the mold cavity containing the filled blow molded article being sealed closed.
FIG. 11 is a cross section of the mold cavity of FIG. 6 showing the formed, filled, and sealed article being removed from the mold cavity.
FIG. 12 is a perspective view of a medical fluid container bag manufactured in accordance with the method of this invention.
FIG. 13 is a cross section of a blow molding die extruding an intermittently layered parison.
FIG. 14 is a cross section of a container bag formed in accordance with the method of this invention by blow molding the parison of FIG. 13.
FIG. 15 is an elevational view of the container bag of FIG. 14 showing a peelable end layer covering access ports.
FIG. 16 is a cross section of a two-layered parison extruded from a blow molding die.
FIG. 17 is a cross section of a container blown from the parison of FIG. 16.
FIG. 18 is a cross section of an intermittently layered parison extruded from a blow molding die.
FIG. 19 is a cross section of a container blown from the parison of FIG. 18.
FIG. 20 is a cross section of an intermittently layered parison extruded from the blow molding die.
FIG. 21 is a front elevational view, in partial section, showing a container having a cap attached to the container neck at a frangible section, blown from the parison of FIG. 20.
FIG. 22 is a cross section of the neck portion and cap of the container of FIG. 21 showing an alternative configuration for the cap.
FIG. 23 is a cross section of a mold cavity accepting a parison having several layered sections.
FIG. 24 is a perspective of a container bag formed from the parison shown in FIG. 23.
FIG. 25 is an alternative construction of the blow molded container bag of FIG. 24.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Turning now to the drawings, FIG. 6 shows two mold cavity sections 10, 12 in their open position. Slide clamps 14, 16 rest on top of mold cavity sections 10, 12. A layered parison 18, extruded from blow molding die 20 is between mold cavity sections 10, 12. Nozzle 22 is shown connected to blow molding die 20.
Parison 18 is formed by extruding thermoplastic material from blow molding die 20. By conventional die programming means, using existing injection or extrusion technology and including reciprocating screw means, a first thermoplastic material 24 is fed (in its molten state) into blow molding die 20. The molten plastic 24 fed into blow molding die 20 is preferably at least at a temperature of about 350° F. Nozzle 22 is shown feeding molten second thermoplastic material 26, incompatible with first thermoplastic material 24, into blow molding die 20. Conventional die programming means, including reciprocating screw means control the feed rate. Typically, second thermoplastic material 26 is also at a temperature of at least 350° F. First thermoplastic material 24 and second thermoplastic material 26 are incompatible materials.
It should be appreciated that the thickness of first thermoplastic material 24 and second thermoplastic material 26 are controlled by their relative feed rates using the normal die programming means. Purely for ease of illustration, the layers of thermoplastic materials are shown roughly of the same thickness in all the figures. Thickness of the layers of thermoplastic material can typically range from 0.001 to 0.2 inch or more.
Second thermoplastic material 26 feeds into reservoir 28 located inside blow molding die 20. In this embodiment of the invention, reservoir 28 is annular. Changes in configuration of reservoir 28 from its annular shape to portions of an arc of an annulus result in the depositing of strips of the second thermoplastic material onto the first thermoplastic material.
By intermittently feeding second thermoplastic material 26 into blow molding die 20, an intermittent layer of second thermoplastic material 26 is deposited onto first thermoplastic material 24. Extruding the simultaneously fed thermoplastic materials from blow molding die 20 forms an intermittently layered thermoplastic parison 18.
In FIG. 7, mold cavity sections 10, 12 have been closed, simultaneously closing off one end of thermoplastic parison 18 and forming mold cavity 19. A frangible section 30 is formed at the closed end of parison 18 when mold cavity sections 10, 12 are closed. Extending tab 32 is also formed.
Blow molding of parison 18 is illustrated in FIG. 8, where ambient air 34 is blown into the closed off parison. At this stage, container bag 36 begins to take shape. Container bag 36 is comprised of first thermoplastic material 24. An outer layer comprised of second thermoplastic material 26 is shown covering bottom end 38 of container bag 36.
FIG. 9 shows container bag 36 after pin 40 has been used to form access port 42 on container bag 36. Filling with desired liquid 44 is accomplished through fill/blow tube 21.
After container bag 36 has been completely filled with fluid contents 44, slide clamps 14, 16 are closed, as is shown in FIG. 10, to seal closed container bag 36. At the same time, pin 40 is retracted completing the formation of access port 42.
FIG. 11 shows a sealed container bag 36. Container bag 36 is then removed from between open mold cavity sections 10, 12.
Completed container bag 36 is shown in FIGS. 11 and 12. Top end 46 has an extending tab 48 having opening 50. Bottom end 38 of container bag 36 is shown covered by second thermoplastic material 26. Access port 42 is also covered by second thermoplastic material 26. Tab 32, having frangible section 30, depends from bottom end 38 of container bag 36.
The container bag 36 formed by the method of this invention has integrally formed access port 42 covered by second thermoplastic material 26. Because of the high temperatures encountered during the feeding and extruding steps in the method of this invention, the interface between thermoplastic materials 24 and 26 is essentially sterile. Since the thermoplastic materials used are incompatible, thermoplastic material 26 may be peeled off the bottom end 38 and access port 42 of container bag 36 just prior to use, thereby offering a sterile surface.
Preferred incompatible thermoplastics 24, of which the container bag 36 is made, include polyolefins such as polypropylene, copolymers having a high polypropylene content, and polyethylene. Polycarbonates may also be used. Preferred incompatible thermoplastic materials for second thermoplastic material 26 which constitutes the outer, peelable layer, include polystyrene, ABS, polyvinylchloride, and fluoropolymers such as polyvinylidene fluoride. Styrene containing thermoplastic elastomers may also be compounded to be incompatible with the thermoplastic material of the container and thus usable.
Turning now to FIG. 23, an alternative embodiment is shown. This embodiment is substantially the same as the embodiment illustrated in FIGS. 6 through 12 except as otherwise described herein. Mold cavity sections 10a, 12a are shown having slide clamps 14a, 16a resting thereon. Parison 18a is shown between mold cavity sections 10a, 12a.
Nozzle 22a is shown connected to blow molding die 20a. A second Nozzle 52 is also shown connected to blow molding die 20a. Nozzle 22a feeds into annular reservoir 28a located in blow molding die 20a. Nozzle 52 feeds into reservoir 54 located in blow molding die 20a. Reservoir 54 may be completely annular, or it may be only a portion of an arc of an annulus.
In this embodiment, three thermoplastic materials have been fed into blow molding die 20a. Feeding of first thermoplastic material 56 is continuous while simultaneous feeding of second thermoplastic material 58 and third thermoplastic material 60 are intermittent. Parison 18a is comprised of first thermoplastic material 56 covered in sections by second thermoplastic material 58 and third thermoplastic material 60.
The article blow molded from parison 18a of FIG. 23 is shown in FIG. 24. Container bag 36a is shown having extending tab 48a having opening 50a at top end 46a. Access port 42a is shown in bottom end 38a of container bag 36a. Thermoplastic material 60 (FIG. 23) made for example of Kraton G (a trademarked plastic manufactured by Shell Oil Company) thermoplastic rubber, forms injection strip 62 on the container bag. Similarly, other known elastomeric materials, for example EVA, may also be used to form injection strips. Injection strip 62 can be used as a sterile injection site for injecting an additive, such as a medicament, into container bag 36a. Access port 42a and bottom end 38a are provided with a peelable layer formed from thermoplastic material 58.
FIG. 25 shows an alternative configuration of the container bag shown in FIG. 24. Container bag 36b is shown with an injection strip 62a formed by feeding third thermoplastic material 60 into a reservoir that is only a portion of an arc of an annulus. Injection strip 62a may be used as a sterile injection site for injecting an additive into container bag 36b. Bottom end 38a and administration site 42a are protected by a peelable layer formed from thermoplastic material 58.
Turning now to FIG. 1, layered parison 64 is shown. Only a portion of blow molding die 66 is shown. However, parison 64 is formed in a manner similar to the method previously described herein.
Parison 64 is formed by feeding first thermoplastic material 68 into blow molding die 66 and extruding first thermoplastic material 68. Second thermoplastic material 70 is simultaneously fed into blow molding die 66 and the simultaneously fed thermoplastic materials 66 and 68 are extruded from blow molding die 66 forming layered portion 72 of thermoplastic parison 64. Thereafter, feeding of first thermoplastic material 68 is terminated with the feeding of second thermoplastic material 70 continuing. Parison 64 is the result of this intermittent simultaneous feeding. In parison 64, first section 69 is free of an overlying layer. Second section 72 has an overlying layer, and third section 73 is free of an underlying layer.
Parison 64 is typically introduced between two mold cavity sections which are subsequently closed to form a mold cavity. Blowing of the parison then proceeds, followed by filling of the blown article, still in a mold cavity.
FIG. 2 shows mold cavity sections 74, 76 in their closed position after parison 64 has been blown, to form container 78 having outlet 79. Container 78 is comprised of first thermoplastic material 68, such as polypropylene. Fill/blow plug 80, within blow molding die 66, is shown projecting therefrom into the mold cavity formed by mold cavity section 74, 76. Shoulder 82 on end portion 84 of fill/blow plug 80 forms neck portion 86 of container 68. Container 78 is shown being filled with any suitable fluid 88. Second thermoplastic material 70 constitutes an outer layer such as polyvinyl chloride on neck 86 of container 78.
Slide plates 90, 92 of FIG. 3 are shown pinching off second thermoplastic material 70 after container 78 has been completely filled. FIG. 4 shows the final step in sealing container 78. Slide plates 90, 92 are opened after sealing slide plate 94 severs second thermoplastic material 70 sealing container 78 at outlet 79 and engaging sealing plate 96 to form tab 98.
FIG. 5 shows closed container 78 filled with a suitable fluid 88. Container 78 is comprised of first thermoplastic material 68 which is covered by a layer of second thermoplastic material 70 at neck 86. Second thermoplastic material 70 also seals outlet 79 of container 78 and terminates in tab 98. Thus material 70 serves as a tear-off cap which provides a sterile seal until torn off.
Turning now to FIG. 13, another parison configuration is shown. Parison 100 is formed in accordance with the method of this invention. Blow molding die 102 is shown extruding parison 100. Fill/blow tubes 104, 106 are located within blow molding die 102. Nozzle 108 is also shown.
In accordance with the method of this invention, first thermoplastic material 110 is continuously fed into blow molding die 102. Second thermoplastic material 112 is thereafter simultaneously fed into blow molding die 102 through nozzle 108.
By intermittent simultaneous feeding of second thermoplastic material 112 into blow molding die 102 and extrusion of the thermoplastic materials from blow molding die 102, layered thermoplastic parison 100 is formed. Intermittent feeding of thermoplastic material 112 forms a parison having first section 114 free of an overlying layer of thermoplastic material and a second section 116 having an overlying layer of thermoplastic material 112.
FIG. 14 illustrates container bag 116 formed by the method of the present invention after blowing and filling through fill/blow tubes 104, 106. Container bag 116 has peelable layer 118 comprised of second thermoplastic material 112 and covering the access port area formed by fill/blow tubes 104, 106. FIG. 15 illustrates container bag 116 after end 124 has been sealed. Access ports 120, 122 are closed by known, conventional means. Peelable outer layer 118 acts as a sterile barrier insuring the sterility of access ports 120, 122 until peelable strip 118 is removed.
FIG. 20 illustrates parison 100a, substantially similar to the parison illustrated in FIG. 13. Parison 100a is formed by continuously feeding first thermoplastic material 110a into blow molding die 102a and intermittently feeding second thermoplastic material 112a into blow molding die 102a. When the thermoplastic materials are extruded from blow molding die 102a, layered, thermoplastic parison 100a is formed. First section 114a of parison 100a is free of an overlying layer and second section 116a of parison 100a has an overlying layer of thermoplastic material 112a. End 128 of parison 100a is closed off in a conventional mold cavity.
The parison is blow molded in the mold cavity to form container 126, which is thereafter filled and sealed by closing cap 132 over container outlet 130. Frangible section 134 couples cap 132 to neck 136 of container 126.
Container 126 and cap 132 are comprised of first thermoplastic material 110a. A portion of neck 136 and cap 132 are covered by an overlying layer of incompatible second thermoplastic material 112a. In this manner, the interface between overlying layer comprised of second thermoplastic material 112a and container 126, comprised of thermoplastic material 110a, remains sterile until the overlying layer is removed by breaking frangible groove 134 to remove cap 132.
FIG. 22 shows an alternative configuration of the cap for the container illustrated in FIG. 21. Thermoplastic material 112a overlies a portion of neck 136a and cap 132a. Cap 132a has a concave indentation 138 which forms frangible connection 140 at container outlet 130 in addition to frangible groove 134a.
Additional alternative embodiments of parisons formed in accordance with the method of the present invention are seen in FIGS. 16 and 18. In FIG. 16, parison 142 is formed by continuously and simultaneously feeding first thermoplastic material 144 and second thermoplastic material 146 into blow molding die 148. The simultaneously fed thermoplastic materials are extruded from blow molding die 148 forming layered parison 142.
Upon blow molding parison 142 in a mold cavity, container 150 is formed. Container 150 is comprised of first thermoplastic material 144 having an overlying layer comprised of incompatible second thermoplastic material 146. The entire exterior of container 150 is covered by a layer of second thermoplastic material 146. Located at the bottom of container 150 is tab 152 connected to container 150 at frangible section 154, to permit removal of outer layer 146. Outer layer 146 can serve as a water vapor or oxygen barrier, or as an opaque protection against light, with inner layer 144 being transparent.
FIG. 18 depicts a parison 142a substantially similar to the parison depicted in FIG. 16 except as otherwise described herein. First thermoplastic material 144a and second thermoplastic material 146a are simultaneously fed into blow molding die 148a. Feeding of first thermoplastic material 144a is then stopped. When the thermoplastic materials are extruded from blow molding die 148a, an intermittently layered parison is formed. First section 156 has an underlying layer of thermoplastic material 144a, and second section 158 is free of an underlying layer.
After blow molding parison 142a, container 150a is formed. Container 150a is comprised of first thermoplastic material 144a having a portion of its exterior covered by an overlying layer of second thermoplastic material 146a. Neck portion 160 of container 150a is free of an overlying layer of thermoplastic material.
Accordingly it can be seen that multiple layer blow molded containers of many different kinds can be made in accordance with this invention, frequently with the respective layers being made of incompatible materials so that one of the layers can be removed for any of various purposes, some of which are described herein. Also the layers can be permanently sealed together and can serve as vapor barriers or the like.
The above has been offered for illustrative purposes, and is not intended to limit the invention of this application, which is defined in the claims below. | Layered thermoplastic articles (36) and a method for forming layered thermoplastic articles are provided. The method involves forming a layered, thermoplastic parison, followed by blow molding the parison in a mold cavity (10, 12) to form a desired configuration of hollow article (36). The blow molded articles (36) can be of any configuration achievable with known blow molding technology. Every section of the article (36) can be layered, or the article (36) can have selectively intermittent layered sections. The containers typically are used for storing and dispensing liquids and are of one-piece construction. In accordance with this invention, the thermoplastic materials (24, 26) are of a type which are incompatible. | 1 |
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application is based upon and claims the benefit of priority from the prior Japanese Patent Application No. 2013-018914 filed on Feb. 1, 2013, the entire contents of which are incorporated herein by reference.
FIELD
[0002] Embodiments are related to an amplifier and an amplifying method.
BACKGROUND
[0003] A power amplifier used for high frequency signal processing is used in various equipments such as a communication apparatus, and an impedance matching in the power amplifier is improved over broadband.
[0004] Japanese Patent Application Laid-Open No. 2011-35761 discloses related technology.
SUMMARY
[0005] According to an aspect of the embodiments, an amplifier includes: an amplifying device configured to amplify an input signal; and a matching circuit coupled to the amplifying device, and including an impedance transformer and a parallel resonance circuit coupled to a wiring which spans from the impedance transformer to the amplifying device, wherein a circuit length of the impedance transformer is longer than one-fourth of wavelength of an electronic wave having a frequency which is substantially equal to a resonance frequency of the parallel resonance circuit.
[0006] The object and advantages of the disclosure will be realized and attained by the elements and combinations particularly pointed out in the claims.
[0007] It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory, and are not restrictive of the invention, as claimed.
BRIEF DESCRIPTION OF DRAWINGS
[0008] FIG. 1 illustrates an example of an amplifier.
[0009] FIG. 2A illustrates an example of an amplifier.
[0010] FIG. 2B illustrates an example of a matching circuit.
[0011] FIG. 3A illustrates an example of a matching circuit.
[0012] FIG. 3B illustrates an example of an impedance relationship between harmonics and a fundamental wave.
[0013] FIG. 4A illustrates an example of a fundamental impedance.
[0014] FIG. 4B illustrates an example of matching circuit.
[0015] FIG. 5 illustrates an example of amplifier.
[0016] FIG. 6A illustrates an example of an impedance transformer.
[0017] FIG. 6B illustrates an example of an impedance transformation circuit.
[0018] FIG. 7A illustrates an example of an impedance transformer.
[0019] FIG. 7B illustrates an example of an impedance transformation circuit.
[0020] FIG. 8 illustrates an example of a relationship between an input reflection coefficient and a frequency of an input signal.
[0021] FIG. 9 illustrates an example of a reactance variation.
[0022] FIG. 10 illustrates an example of a frequency characteristic adjustment method.
[0023] FIG. 11 illustrates an example of a parallel resonance circuit.
[0024] FIG. 12 illustrates an example of a parallel resonance circuit.
[0025] FIG. 13A and FIG. 13B illustrate an example of a relationship between frequency of an input signal and an amount of attenuation of the input signal.
[0026] FIG. 14 illustrates an example of parallel resonance circuit.
[0027] FIG. 15 illustrates an example of a relationship between frequency of an input signal and an amount of attenuation of the input signal.
[0028] FIG. 16 illustrates an example of an impedance variation.
[0029] FIG. 17 illustrates an example of impedance transformer.
[0030] FIG. 18 illustrates an example of an amplifier.
DESCRIPTION OF EMBODIMENTS
[0031] FIG. 1 illustrates an example of an amplifier. The amplifier illustrated in FIG. 1 includes, for example, a transistor 1 which amplifies a high frequency signal, an impedance transformer 4 which is a transmission line having a line length of one-fourth wavelength of a use frequency, a series inductor 6 , a stub 2 , a capacitor 3 and an open stub 7 . Signal is input to the transistor 1 through an input matching circuit 5 . One end of the series inductor 6 is coupled to an output terminal of the transistor 1 , and the stub 2 and the open stub 7 are coupled to the other end of the series inductor 6 . The stub 2 is coupled to the capacitor 3 to short-circuit high frequency signals, and the stub 2 , the open stub 7 and the capacitor 3 are operated as a resonance circuit. One end of the impedance transformer 4 is coupled to a connection point of one end of the open stub 7 and one end of the stub 2 . The resonance circuit coupled to the impedance transformer 4 in parallel conjugate matches an impedance of the impedance transformer with another impedance of the resonance circuit side seen from the connection point of the impedance transformer 4 and the resonance circuit.
[0032] When the conjugate matching is performed to be adjusted to the impedance characteristic of the impedance transformer, the parallel resonance circuit is designed such that the inductive reactance is employed in a frequency region having a relatively low frequency and the capacitive reactance is employed in another frequency region having a relatively high frequency among the use frequencies in accordance with the impedance characteristic of the impedance transformer. In such a design, since an operation band of the resonance circuit becomes narrower, the variation of reactance due to the deviation of the device included in the resonance circuit becomes large. When an effect of the device deviation is large, it may be difficult to manufacture a stable amplifier.
[0033] FIG. 2A illustrates an example of an amplifier. The amplifier 10 illustrated in FIG. 2 includes, for example, an amplification device 11 and a matching circuit 20 , and is coupled to an output load. The amplification device 11 may be, for example, a transistor. In the amplifier 10 , the matching circuit 20 is arranged to be coupled between the amplification device 11 and the output load 12 . FIG. 2B illustrates an example of a matching circuit. The matching circuit 20 includes, for example, a transmission line 21 , a parallel resonance circuit 30 and an impedance transformer 40 .
[0034] FIG. 3A illustrates an example of a matching circuit. For example, a target matching value at the time when the frequency characteristic of the matching circuit 20 is adjusted is obtained as follows. As illustrated in FIG. 3A , the matching circuits, for example, the output matching circuit 20 and the input matching circuit 25 , may be coupled to the input and output of the amplification device 11 , respectively. In this case, an output current output from the amplification device 11 is represented by a cosine wave and the harmonics according to an input bias condition. When the input bias condition corresponds to the bias condition of Class B amplifier, the output current is represented by the following equation (1).
[0000]
i
(
θ
)
=
1
π
+
1
2
cos
θ
+
2
3
π
cos
2
θ
-
2
15
π
cos
4
θ
+
2
35
π
cos
6
θ
-
…
(
1
)
[0035] A waveform an output voltage of the matching circuit 20 is represented by the equation (2).
[0000]
v
(
θ
)
=
1
-
cos
θ
-
α
sin
θ
+
1
2
α
sin
2
θ
(
2
)
[0036] For example, an equation may be used as described in an article by Steve C. Cripps et. al., entitled “On the Continuity of High Efficiency Modes in Linear RF Power Amplifiers”, IEEE Microwave and Wireless Components Letters, Vol. 19, No. 10, pp. 665-667, October 2009. The coefficient “a” is a value satisfying −1≦α≦1 and a coefficient of the term of the harmonics and the fundamental wave. The waveform of the output current is sum of the cosine wave and harmonics of the cosine wave. A voltage component that can be represented by the sine wave and the harmonics of the sine wave among the equation (2) is orthogonal to a current component represented by the cosine wave and the harmonics of the cosine wave of the output current. Thus, there may be no influence on the power efficiency. Therefore, a load matching circuit which generates the voltage of the equation (2) may have substantially the same efficiency as another load matching circuit which generates a voltage of 1−cos θ. In a case of Class B amplifier, the voltage may be 1−cos θ. Therefore, both impedances of the second order harmonic and the fundamental wave are matched in the matching circuit, the amplification device 11 may operate as a high-efficiency amplifier corresponding to Class B amplifier.
[0037] FIG. 3B illustrates an example of a relationship between impedances of the harmonics and a fundamental wave. For simplification, FIG. 3B illustrates the variation of impedances of the second order harmonic and a fundamental wave based on the frequency for a case where a parallel load capacitance of the amplification device 11 is negligible. In the impedance of the fundamental wave, the resistance component is not varied and the reactance component becomes gradually smaller as the value of the “α” in the equation (2) becomes larger. Therefore, the impedance of the fundamental wave may move in a counter-clockwise direction on the equal resistance line in the Smith Chart illustrated in FIG. 3B , as the value of the “α” increases. In the impedance of the second order harmonic, the resistance component is not present and the reactance component increases as the value of the “α” in the equation (2) increases. Therefore, the impedance of the second order harmonic moves in a clockwise direction on the periphery in the Smith Chart illustrated in FIG. 3B . The impedance of the matching circuit is matched to either impedance of the second order harmonic or impedance of the fundamental wave according to the frequency in the matching circuit and thus, a band that is efficiently amplified may be widened. The impedances of the fundamental wave and the second order harmonic of the respective frequencies f1-f5 are represented in FIG. 3B . The frequency may become higher in the order of f1<f2<f3<f4<f5 in FIG. 3B .
[0038] FIG. 4A illustrates an example of an impedance of fundamental wave. FIG. 4B illustrates an example of a matching circuit. The impedance of the fundamental wave output from the amplification device 11 is illustrated in FIG. 4A . When the amplification device 11 and the matching circuit 20 are matched with each other in the amplifier 10 illustrated in FIG. 4B , the impedance illustrated in FIG. 4A may be an impedance obtained from the matching circuit 20 side seen from the connection point of the amplification device 11 and the matching circuit 20 . The points surrounded by a circle illustrated with a bold line in FIG. 4A represent theoretical values obtained from the matching circuit 20 which is in matching with respect to signals having frequencies of f1, f2, f3, f4, f5. As the frequency becomes higher, the impedance of the matching circuit 20 varies as represented by the arrow. For example, when the impedance of the matching circuit is matched with the fundamental wave of an output from the amplification device 11 , the target value of impedance of the matching circuit 20 may be points surrounded by a circle illustrated with a bold line in FIG. 4A . The second order harmonic is matched to the value indicated in FIG. 3 .
[0039] The impedance transformer 40 adjusts the resistance component of the impedance of the output load 12 to the target impedance for matching. The impedance transformer 40 may be designed such that variation of the reactance component based on variation of the frequency of the input signal becomes small. The circuit length of the impedance transformer 40 is made longer than one-fourth of the wavelength of an electronic wave having a frequency substantially equal to the resonance frequency of the parallel resonance circuit 30 . As a result, the variation of the reactance in the impedance transformer may become small. The impedance transformer 40 may be designed such that the variation of the reactance in the impedance transformer 40 becomes smaller than the variation of the reactance component based on the variation of the frequency in a device side rather than the transmission line 21 . For example, the impedance transformer 40 may be designed such that the variation of the reactance seen at the impedance transformer 40 due to the variation of the frequency is small enough to be excluded from the targets for the conjugate matching. For example, the impedance transformer 40 may be designed such that the variation of the reactance in the impedance transformer 40 due to the variation of the frequency of signal is smaller than the variation of the reactance in the amplification device 11 based on the variation of the frequency of signal.
[0040] FIG. 5 illustrates an example of an amplifier. The amplifier illustrated in FIG. 5 includes, for example, the impedance transformer 40 including a plurality of impedance transformation circuits 41 . The impedance transformer 40 illustrated in FIG. 5 includes, for example, the impedance transformation circuits 41 a and 41 b , but the number of impedance transformation circuits included in impedance transformation circuit 41 may be two or more. Electrical length or value of characteristic impedance of each impedance transformation circuit 41 may be set arbitrarily, and the circuit length of the impedance transformer 40 may be longer than one-fourth of wavelength of an electronic wave having the frequency substantially equal to the resonance frequency of the parallel resonance circuit 30 . The wavelength of the electronic wave having the frequency substantially equal to the resonance frequency of the parallel resonance circuit 30 may be referred to as λ.
[0041] FIG. 6 illustrates an example of an impedance transformer. In FIG. 6 , one end of the impedance transformer 40 and an oscillator are coupled with each other while sandwiching 50Ω resistor therebetween. The other end of the impedance transformer 40 is grounded while sandwiching 100Ω resistor between the impedance transformer 40 and ground. The impedance transformer 40 illustrated in FIG. 6A includes, for example, the impedance transformation circuit 41 a and the impedance transformation circuit 41 b . The characteristic impedance and the circuit length of the impedance transformation circuit 41 a may be 61.2Ω and λ/4, respectively. The characteristic impedance and the circuit length of the impedance transformation circuit 41 b may be 86.6Ω and λ/4, respectively. In FIG. 6 , the characteristic impedance is represented by Z0. As illustrated in FIG. 6A , the plurality of impedance transformation circuits 41 may have substantially the same circuit length as well as different circuit lengths. In FIG. 6A , the circuit length of the impedance transformer 40 may be λ/2. Each impedance transformation circuit 41 may be formed by using, for example, a transmission line. The impedance transformer 40 may be formed by coupling a plurality of transmission lines having different line widths. FIG. 6B illustrates an example of an impedance transformation circuit. In FIG. 6B , the impedance transformer 40 illustrated in FIG. 6A is formed by using the transmission line. In FIG. 6B , the line length of the impedance transformation circuit 41 a and that of the impedance transformation circuit 41 b is substantially equal, but the line width of the impedance transformation circuit 41 a may be wider than that of the impedance transformation circuit 41 b . In FIGS. 6A and 6B , each impedance transformation circuit 41 having the transmission line length of λ/4 is illustrated, but the line length of the impedance transformation circuit 41 may be changed according to installation conditions. The characteristic impedance of the impedance transformation circuit 41 may also be adjusted according to installation conditions. The characteristic impedance may be calculated as a function of, for example, a line thickness, a substrate thickness and a dielectric constant of substrate, when the impedance transformer 40 is designed. When the impedance transformation circuit 41 is designed, for example, Binomial multisection matching transformers or Chebyshev multisection matching transformers may be used.
[0042] FIG. 7A illustrates an example of an impedance transformer. In FIG. 7A , the impedance transformer 40 is illustrated for a case where the line length of the impedance transformation circuit 41 is not λ/4. In FIG. 7A , the transmission lines having the transmission line length of 18.27/360λ are used as the impedance transformation circuits 41 ( 41 c - 41 k ), and nine impedance transformation circuits 41 are coupled in series. Therefore, the entire line length of the impedance transformer 40 illustrated in FIG. 7A may be 164.47/360λ. The impedance Z of each impedance transformation circuit 41 is represented by the equation (3), when each impedance transformation circuit 41 illustrated in FIG. 6 and FIG. 7A sees an output terminal thereof from an input terminal thereof.
[0000]
Z
=
Z
0
Z
r
+
j
·
Z
0
·
tan
(
2
·
π
·
l
λ
s
)
Z
0
+
j
·
Z
r
·
tan
(
2
·
π
·
l
λ
s
)
(
3
)
[0043] Z0 is the characteristic impedance of the line, Zr is a load of the output end, and λs is wavelength of the signal input to the impedance transformation circuit 41 .
[0044] The characteristic of the impedance transformer 40 may be evaluated using reflection of signal (e.g., s11 characteristic) or the variation of the reactance based on the variation of the frequency of the input signal.
[0045] FIG. 8 illustrates an example of a relationship between an input reflection coefficient and a frequency of an input signal. The solid line illustrated in FIG. 8 represents the input reflection coefficient (s11) of the signal of the impedance transformer 40 illustrated in FIG. 7A as a function of the wavelength λs of the signal. The dashed-line illustrated in FIG. 8 represents the relationship between the input reflection coefficient and the frequency of the input signal in a case where a single impedance transformation circuit 41 is used as the impedance transformer. In the configuration of FIGS. 7A and 7B , the input signal may be generated by the oscillator. In a graph represented in FIG. 8 , the value indicated by the solid line is smaller than that indicated by the dashed-line in a frequency range of from 1 GHz to 3 GHz. Therefore, when the impedance transformer 40 illustrated in FIG. 7A is used, the reflection coefficient in the impedance transformer may become smaller and the characteristic of the impedance transformer may be enhanced in the frequency range of 1 GHz to 3 GHz 1 , as compared to a case where the impedance transformer 40 illustrated in FIG. 7B is used.
[0046] FIG. 9 illustrates an example of a variation of the reactance. FIG. 9 illustrates the variation of the reactance based on the variation of the frequency of the input signal. “A” in FIG. 9 represents the variation of the reactance component of the output signal in a case where the frequency of the input signal to the impedance transformer 40 illustrated in FIG. 6A varies from f1 to f5. “B” in FIG. 9 represents the variation of the reactance component of the output signal in a case where the frequency of the input signal to the impedance transformer illustrated in FIG. 7B is varied from f1 up to f5. The impedance transformer illustrated in FIG. 7B is formed by a single stage of the impedance transformation circuit 41 . FIG. 9 may be represented such that the variation of the reactance component becomes smaller as the number of the impedance transformation circuits 41 increases.
[0047] The impedance transformer 40 may include, for example, a multi-stage of the impedance transformer including a plurality of the impedance transformation circuits 41 , causing the variation of the reactance component based on the variation of the frequency of the input signal to the impedance transformer 40 to become smaller. When the impedance transformer 40 in which the variation of the reactance component is small is used, the parallel resonance circuit 30 in the matching circuit 20 may not be required to match the variation of the reactance component generated by the impedance transformer 40 . Therefore, when the impedance transformer 40 in which the variation of the reactance component is smaller is used, the parallel resonance circuit 30 may not be required to perform a matching operation in accordance with the variation of the reactance generated by the impedance transformer 40 . Therefore, an operating frequency band of the parallel resonance circuit 30 may be broadened.
[0048] FIG. 10 illustrates an example of a frequency characteristic adjustment method. A method of adjusting the frequency characteristic of the matching circuit 20 is illustrated in FIG. 10 . The frequency characteristic of the matching circuit 20 is adjusted to a target matching value.
[0049] “A” on the Smith Chart of FIG. 10 represents the impedance of the output load 12 . Impedance characteristics of the fundamental wave of the output from the amplification device 11 may correspond to a plurality of points of “B” as illustrated in FIG. 10B . The impedance of the output load 12 is adjusted to the value of the resistance component of the target matching impedance by the impedance transformer 40 . When the impedance transformer 40 is coupled to the output load 12 , the impedance becomes “C” as illustrated in FIG. 10 . Further, the transmission line 21 is coupled to the impedance transformer 40 and thus, the reactance component is adjusted to the value around the target impedance “B”.
[0050] The impedance characteristic of the second order harmonic output from the amplification device 11 becomes a circle moving in a clockwise direction along an outer periphery of the Smith chart as illustrated in FIG. 3B . Thus, the target matching value with respect to the second order harmonic is represented as “D” in FIG. 10 . The impedance characteristic of the matching circuit 20 may be adjusted to at least one of a target impedance, which varies in clockwise direction, of the second order harmonic, and another target impedance, which varies in a counter-clockwise direction, of the fundamental wave using the parallel resonance circuit 30 .
[0051] FIG. 11 illustrates an example of a parallel resonance circuit. The parallel resonance circuit 30 illustrated in FIG. 11 includes, for example, a capacitor 31 and an inductor 32 . When the capacitance of the capacitor 31 is defined as C and the inductance of the inductor 32 is defined as L, the resonance frequency f of the parallel resonance circuit 30 is represented by the following equation (4).
[0000]
f
=
1
2
·
π
·
L
·
C
(
4
)
[0052] Half-width (bandwidth) of the resonance curve of the parallel resonance circuit 30 is represented by the equation (5) in proportional to the conductance of a resistor coupled to the resonance circuit in parallel.
[0000]
Δ
f
∝
1
2
·
π
·
C
(
5
)
[0053] The bandwidth of the parallel resonance circuit 30 becomes wider as the variation of the reactance component due to (by) the frequency of the signal input to the parallel resonance circuit 30 becomes smaller. In the amplifier 10 illustrated in FIG. 2A , the variation of the reactance component in the impedance transformer 40 due to the input frequency is small and thus, the parallel resonance circuit 30 may not be required to match the variation amount of the reaction due to the impedance transformer 40 . Therefore, the bandwidth of the parallel resonance circuit 30 may become larger as compared to a case where the variation amount due to the impedance transformer 40 is included to be matched. In the amplifier 10 illustrated in FIG. 2A , an effect due to the device deviation of each device included in the parallel resonance circuit 30 may be reduced.
[0054] In the equation (5), the bandwidth is proportional to the reciprocal of the capacitance of the capacitor 31 included in the parallel resonance circuit 30 . Therefore, the bandwidth of the parallel resonance circuit 30 may become wider as the capacitance of the capacitor 31 becomes smaller. When the bandwidth of the parallel resonance circuit 30 becomes wider, the variation of the reactance component based on the device deviation becomes smaller and thus, the amplifier may become robust against the device deviation.
[0055] The parallel resonance circuit 30 may include an open stub 33 and a short stub 34 . When the parallel resonance circuit 30 includes the open stub 33 and the short stub 34 , the parallel resonance circuit 30 is designed using the transmission line and thus, the parallel resonance circuit 30 may be used even when the frequency of the signal is high.
[0056] FIG. 12 illustrates an example of a parallel resonance circuit. Assuming that the wavelength of electronic wave of the resonance frequency of the parallel resonance circuit 30 is λ, the impedance of the open stub 33 is represented by the following equation (6).
[0000]
Z
=
Z
0
op
·
1
j
·
tan
(
2
·
π
·
l
op
λ
)
(
6
)
[0057] where, the characteristic impedance and the line length of the open stub 33 are Z 0op and l op , respectively.
[0058] Assuming that the characteristic impedance and the line length of the short stub 34 are Z 0sh and I sh , respectively, the impedance of the short stub 34 is represented by the following equation (7).
[0000]
Z
=
Z
0
sh
·
j
·
tan
(
2
·
π
·
l
sh
λ
)
(
7
)
[0059] The line length l op of the open stub 33 and the line length 6 of the short stub 34 need to satisfy a relationship represented by the following equation (8) in order for the parallel resonance circuit 30 to resonate at the wavelength λ.
[0000]
Z
0
sh
Z
0
op
·
tan
(
2
·
π
·
l
op
λ
)
·
tan
(
2
·
π
·
l
sh
λ
)
=
1
(
8
)
[0060] When the open stub 33 is coupled with the short stub 34 in parallel, the impedance Z is represented by the following equation (9).
[0000]
Z
=
1
1
Z
0
op
j
·
tan
(
2
·
π
·
l
op
λ
)
+
1
Z
0
sh
·
j
·
tan
(
2
·
π
·
l
sh
λ
)
(
9
)
[0061] The open stub 33 serves as a condenser of an LC resonance circuit and thus, the value in the equation (9) corresponding to jω 0 C is represented by the equation (10).
[0062] Here, ω 0 is a resonance frequency.
[0000]
1
Z
0
op
j
·
tan
(
2
·
π
·
l
op
λ
0
)
(
10
)
[0063] As for the LC resonance circuit, the half-width (bandwidth) of the resonance curve is represented by the following equation (11).
[0000]
Δ
f
=
G
2
·
π
·
C
(
11
)
[0064] Here, G is conductance. Accordingly, the half-width (bandwidth) of the resonance curve of the parallel resonance circuit 30 from the equation (10) and the equation (11) may approximately proportional to the value of the following equation (12).
[0000]
Z
0
op
·
1
tan
(
2
·
π
·
l
op
λ
)
(
12
)
[0065] The half-width (bandwidth) of the resonance curve of the parallel resonance circuit 30 from the equation (8) and the equation (12) may be approximately proportional to the value of the following equation (13).
[0000]
Z
0
sh
·
tan
(
2
·
π
·
l
sh
λ
)
(
13
)
[0066] FIG. 13A and FIG. 13B illustrate an example of a relationship between a frequency and an amount of attenuation of an input signal. FIG. 13A illustrates a relationship between the frequency of the input signal and the signal attenuation when the values represented by the equation (12) and the equation (13) are varied with respect to the parallel resonance circuit 30 . The table of FIG. 13B lists values represented by the equation (12) or the equation (13) with respect to each curve indicated in the graph of FIG. 13A . When referring to FIG. 13A and FIG. 13B , the variation of the attenuation amount of the signal at the time when the frequency of the input signal is varied becomes smaller as the values represented by the equation (12) or the equation (13) become larger. The fact that the variation of the attenuation amount of the signal according to the variation of the frequency of the signal is small indicates that the frequency band over which the parallel resonance circuit 30 is used is wide. Therefore, the frequency band over which the parallel resonance circuit 30 may use becomes wide as the value of the parallel resonance circuit 30 indicated by the equation (12) or the equation (13) becomes larger. When the frequency band over which the parallel resonance circuit 30 may be used is wide, the deviation effect of the devices included in the parallel resonance circuit 30 may be reduced.
[0067] As illustrated in FIG. 10 , when matching is made with respect to the second order harmonic input from the amplification device 11 , the target value may be on the outer periphery of the Smith chart. Therefore, when the parallel resonance circuit 30 is designed such that the signal of the second order harmonic at the frequency band of the signal intended to be amplified is short-circuited at the stub, the characteristic may be improved. The resonance frequency of the parallel resonance circuit 30 may be substantially the center of the frequency band of the signal intended to be amplified. The signal of the frequency lower than the resonance frequency is short-circuited and thus, when the length of the open stub 33 is set to one-eighth or less of the wavelength of the fundamental wave, the efficiency may be improved. Therefore, the length of the open stub 33 becomes one-fourth or less of the wavelength with respect to the second order harmonic.
[0068] The short stub 34 is required to have characteristic similar to an inductance and thus, when the line length is set to one-fourth or less of the wavelength of the fundamental wave, the characteristic may be improved. The impedance of the short stub 34 is represented by the equation (7) and thus, the line length of the short stub 34 may be set equal to or greater than 2nλ/4 and equal to or less than (2n+1)λ/4, where n is a positive integer.
[0069] The amplification device 11 , the transmission line 21 and the impedance transformer 40 included in the amplifier 10 illustrated in FIG. 12 may be substantially the same or similar to elements of the amplifier 10 illustrated in FIG. 2B . The variation of the reactance component based on the impedance transformer 40 may become small also in the amplifier 10 illustrated in FIG. 12 . Therefore, the parallel resonance circuit 30 may be designed without considering the effect of variation of the reactance component by the impedance transformer 40 . The bandwidth over which the parallel resonance circuit 30 operates may become wider as compared to the resonance circuit used in a circuit including an impedance transformer in which the variation of the reactance component based on the frequency of the signal is large. The deviation effect of the device included in the parallel resonance circuit 30 may be reduced in the amplifier 10 .
[0070] FIG. 14 illustrates an example of a parallel resonance circuit. The parallel resonance circuit 30 illustrated in FIG. 14 includes, for example, the capacitor 31 and the short stub 34 . The amplification device 11 , the transmission line 21 and the impedance transformer 40 included in the amplifier 10 illustrated in FIG. 14 may be substantially the same or similar to the elements of the amplifier 10 illustrated in FIG. 2B or FIG. 12 .
[0071] Assuming that the wavelength of electronic wave at the resonance frequency of the parallel resonance circuit 30 is λ, the capacitance of the capacitor 31 is C, the characteristic impedance of the transmission line of the stub part of the short stub 34 is Z0, and the transmission line length is I sh , the resonance frequency f of the parallel resonance circuit 30 illustrated in FIG. 14 is represented by the following equation (14).
[0000]
f
=
1
2
·
π
·
C
·
Z
0
·
tan
(
2
·
π
·
l
sh
λ
)
(
14
)
[0072] The bandwidth of the parallel resonance circuit 30 becomes wider by making the value of 1/(2nC) large. For example, the capacitance C of the capacitor 31 becomes small to make the value of 1/(2nC) large.
[0073] FIG. 15 is a view illustrating an example of a relationship between the frequency and an attenuation amount of the input signal. FIG. 15 illustrates the relationship between the frequency and the attenuation of the input signal when the capacitance of the capacitor 31 is made to vary with respect to the parallel resonance circuit 30 . FIG. 15 illustrates that the attenuation amount of the input signal becomes smaller as the capacitance of the capacitor 31 becomes smaller. The variation of the attenuation amount of signal becomes smaller at the time when the frequency of the input signal is varied as the capacitance of the capacitor 31 becomes smaller. Small attenuation amount of the signal over broadband or small variation of the attenuation amount of the signal according to variation of the frequency of the signal may indicate that the frequency band over which the parallel resonance circuit 30 may be used is wide. Therefore, the useable frequency band becomes wider as the capacitance of the capacitor 31 becomes smaller in the parallel resonance circuit 30 as illustrated in FIG. 14 . When the frequency band over which the parallel resonance circuit 30 may be used is wide, the deviation effect of the devices included in the parallel resonance circuit 30 may be reduced.
[0074] The impedance of the short stub 34 included in the parallel resonance circuit 30 illustrated in FIG. 14 is represented by the equation (7). The short stub 34 is required to have characteristic similar to an inductance and thus, when the line length is set to one-fourth or less of the wavelength of the fundamental wave, the characteristic may be improved. The transmission line length of the short stub 34 may be set equal to or greater than 2 nλ/ 4 and equal to or less than (2n+1)λ/4, where n is a positive integer.
[0075] The characteristic impedance of the transmission line 21 may be set, for example, to larger than that of the output load 12 . The transmission line 21 may be used for adjusting the reactance component of the impedance. A rotation angle of the reactance component of the impedance of the transmission line 21 on the Smith chart becomes smaller as the characteristic impedance of the transmission line 21 becomes larger. Therefore, when the adjustment amount of the reactance is an equal amount, the length of the transmission line 21 may be set to a smaller length as the characteristic impedance of the transmission line 21 becomes higher.
[0076] FIG. 16 illustrates an example of impedance variation. The impedance variation in the transmission line 21 is illustrated in FIG. 16 . “A” of FIG. 16 illustrates an example of the impedance variation in the transmission line 21 having the characteristic impedance higher than the characteristic impedance of the output load 12 . “B” of FIG. 16 illustrates an example of the impedance variation in the transmission line 21 having the characteristic impedance which is equal to the characteristic impedance of the output load 12 . The varying amount of the frequency of the input signal may be substantially the same at any of the curve “A” and “B”. It may be seen from FIG. 16 that the length of the curve “A” is smaller than that of the curve “B”. Therefore, the characteristic impedance of the transmission line 21 is made larger than that of the output load 12 , such that the line length may become smaller.
[0077] FIG. 17 illustrates an example of an impedance transformer. FIG. 2A illustrates the impedance transformer 40 in which the transmission lines having different line width are coupled to each other and the transmission line width varies step-wise over the length as illustrated in FIG. 17A . The line width may vary continuously as illustrated in FIG. 17B . The line length of the impedance transformer 40 varies according to the variation angle of the line width and thus, the freedom of design may be increased. The impedance transformer 40 having the line width varying continuously as illustrated in FIG. 17B may correspond to a single impedance transformation circuit 41 having the line width varying continuously. The impedance transformer 40 having the line width varying continuously may correspond to a single impedance transformer formed by coupling numerous step-shaped impedance transformers 41 . Therefore, when the impedance transformer 40 having the line width varying continuously is used, the variation of the reactance due to the variation of the frequency of the signal may be reduced, similar to the impedance transformer 40 including a plurality of step-shaped impedance transformation circuits 41 . The impedance transformer 40 illustrated in FIG. 17B may have the line length longer than one-fourth of the wavelength of the electronic wave having the frequency which is substantially equal to the resonance frequency of the parallel resonance circuit 30 . The impedance transformer 40 illustrated in FIG. 17B may be used in the parallel resonance circuit of FIG. 2B , FIG. 12 and FIG. 14 .
[0078] When the open stub 33 or the short stub 34 is used, the line length may be adjusted by varying the characteristic impedance of the open stub 33 or the short stub 34 . For example, the impedance of the open stub 33 is represented by the following equation (15). Therefore, when the characteristic impedance Z 0op of the open stub 33 is made small, the value of the equation (16) may become small in a case where the line length is adjusted using the same impedance.
[0000]
Z
=
Z
0
op
·
1
j
·
tan
(
2
·
π
·
l
op
λ
)
(
15
)
tan
(
2
·
π
·
l
op
λ
)
(
16
)
[0079] When the characteristic impedance Z 0op of the open stub 33 is made small while keeping the impedance of the open stub 33 constant, the line length lop of the open stub 33 may become shorter. The impedance with respect to the short stub 34 is represented by the following equation (17).
[0000]
Z
=
Z
0
sh
·
j
·
tan
(
2
·
π
·
l
sh
λ
)
(
17
)
[0080] When the characteristic impedance Z 0sh of the short stub 34 is made small, the value of the following equation (18) may become large in a case where the line length is adjusted using the same impedance.
[0000]
tan
(
2
·
π
·
l
sh
λ
)
(
18
)
[0081] When the characteristic impedance Z 0sh of the open stub 34 is made large while keeping the impedance of the short stub 34 constant, the line length I sh of the short stub 34 may become shorter.
[0082] FIG. 18 illustrates an example of an amplifier. The amplifier 10 illustrated in FIG. 18 includes, for example, the amplification device 11 and a matching circuit 50 . The matching circuit 50 includes, for example, the transmission line 21 , the parallel resonance circuit 30 , the impedance transformer 40 and a bias circuit 22 . The bias circuit 22 may be any circuit which supplies a bias power to the amplification device 11 . The amplifier illustrated in FIG. 18 may be used together with the configurations illustrated in FIGS. 1 through 18 .
[0083] The transmission line may be coupled to the impedance transformer 40 in series or in parallel.
[0084] All examples and conditional language recited herein are intended for pedagogical purposes to aid the reader in understanding the invention and the concepts contributed by the inventor to furthering the art, and are to be construed as being without limitation to such specifically recited examples and conditions, nor does the organization of such examples in the specification relate to a showing of the superiority and inferiority of the invention. Although the embodiments of the present invention have been described in detail, it should be understood that the various changes, substitutions, and alterations could be made hereto without departing from the spirit and scope of the invention. | An amplifier includes: an amplifying device configured to amplify an input signal; and a matching circuit coupled to the amplifying device, and including an impedance transformer and a parallel resonance circuit coupled to a wiring which spans from the impedance transformer to the amplifying device, wherein a circuit length of the impedance transformer is longer than one-fourth of wavelength of an electronic wave having a frequency which is substantially equal to a resonance frequency of the parallel resonance circuit. | 7 |
BACKGROUND OF THE INVENTION
The subject matter of the present application relates to semiconductor devices of integrated circuits and their fabrication, particularly field effect transistors.
One of the ways proposed to improve performance in complementary metal oxide semiconductor (“CMOS”) technology integrated circuits is to provide a high dielectric constant, i.e., “high-k” gate dielectric layer, for n-type and p-type field effect transistors (“NFET” and “PFET” devices), and to form metal gates of the NFET and PFET devices.
However, differences in the workfunctions of NFET and PFET devices typically require different metal layers to be provided in the gates of respective N- or P-type transistors. Heretofore, methods for forming the gates of N- and P-type transistors have been cumbersome. Further improvements in the fabrication of N- and P-type transistors having metal gates can be made.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an illustrative flow chart of methods of embodiments of the present invention.
FIG. 2 is a sectional view illustrating a possible starting point of embodiments of the present invention.
FIG. 3 is a sectional view illustrating the formation of a high-k layer according to an embodiment of a method of the present invention.
FIG. 4 is a sectional view illustrating the formation of a blocking stack and lithographic stack according to an embodiment of a method of the present invention.
FIG. 5 is a sectional view illustrating of patterning the blocking stack and the lithographic stack according to an embodiment of a method of the present invention.
FIG. 6 is a sectional view illustrating of patterning the thinning the blocking stack according to an embodiment of a method of the present invention.
FIG. 7 is a sectional view illustrating the formation of a doping layer according to an embodiment of a method of the present invention.
FIG. 8 is a sectional view illustrating forming an annealing stack and the substrate post annealing according to an embodiment of a method of the present invention.
FIG. 9 is a sectional view illustrating the substrate after removing annealing, mask and doping layers according to an embodiment of a method of the present invention.
FIG. 10 is a sectional view illustrating the substrate after patterning a first work function metal stack according to an embodiment of a method of the present invention.
FIG. 11 is a sectional view illustrating the substrate after forming a second work function metal stack according to an embodiment of a method of the present invention.
FIG. 12 is a sectional view illustrating the substrate after filling openings according to an embodiment of a method of the present invention.
FIG. 13 is an illustrative flow chart of a method of a direct doping embodiment of the present invention.
FIG. 14 is a sectional view illustrating a possible starting point in an embodiment of a method of the present invention.
FIG. 15 is a sectional view illustrating the formation of a high-k layer according to an embodiment of a method of the present invention.
FIG. 16 is a sectional view illustrating the formation of a dopant layer according to an embodiment of a method of the present invention.
FIG. 17 is a sectional view illustrating the formation of a mask stack according to an embodiment of a method of the present invention.
FIG. 18 is a sectional view illustrating of patterning a lithographic stack according to an embodiment of a method of the present invention.
FIG. 19 is a sectional view illustrating of patterning the dopant layer according to an embodiment of a method of the present invention.
FIG. 20 is a sectional view illustrating of thinning the mask stack according to an embodiment of a method of the present invention.
FIG. 21 is a sectional view illustrating forming an annealing stack according to an embodiment of a method of the present invention.
FIG. 22 is a sectional view illustrating the substrate after annealing according to an embodiment of a method of the present invention.
FIG. 23 is a sectional view illustrating the substrate after removing annealing, mask and doping layers according to an embodiment of a method of the present invention.
FIG. 24 is a sectional view illustrating the substrate after patterning a first work function metal stack according to an embodiment of a method of the present invention.
FIG. 25 is a sectional view illustrating the substrate after forming a second work function metal stack according to an embodiment of a method of the present invention.
FIG. 26 is a sectional view illustrating the substrate after filling openings according to an embodiment of a method of the present invention.
SUMMARY OF THE INVENTION
The present invention improves performance in complementary metal oxide semiconductor (“CMOS”) technology integrated circuits by providing methods for doping the high dielectric constant, i.e., “high-k” gate dielectric layer, of an FET in a replacement metal gate integration scheme.
The present invention advantageously uses selective etching of multi-layered stacks containing a sacrificial film or controlled etching of single layered blocking stack to form high-k replacement metal gate structures made using soft metal mask without degradation of device properties of the transistors. The methods allow threshold differences to be created among different types of FETs or the same type of FET. Presented are doping methods using the stack as a buffer or blocking stack during doping. Another method is a direct doping method of the high-k using a multi-layered stack as a mask.
In one embodiment, herein referred to “embodiment A”, a blocking stack allows a replacement metal gate structure having one doped and one undoped high-k gate oxide to be formed in a first and second transistor, respectively. In the context of all the embodiments, the term “doping” refers to the incorporation of metal elements (such as, but not limited to, rare-earth elements like lanthanum) into the high-k gate dielectric film to change the effective work function of the transistor. The method uses a multi-layered blocking layer, which due to its multi-layers, may be initially thick and then later thinned. It is advantageous to have a thick layer when patterning using a soft mask to protect the underlying gate materials from damage during the soft-mask reactive ion etching (RIE) process. The patterning reveals the high-k material in a first FET which is to be doped and leaves the blocking stack on the second FET which is to remain undoped. After the soft mask patterning, the multi-layered blocking stack is thinned and a doping layer is formed everywhere. An anneal migrates dopant into the first high-k layer but the thinned blocking layer keeps the dopant away from the second FET's high-k layer. It is advantageous to have a thinned blocking layer during dopant drive-in to minimize the amount of dissolved oxygen in the TiN blocking layer that diffuses through the underlying gate materials during the high temperature anneal process to prevent adverse impact on Tinv (inverse of gate capacitance). The multi-layered stack may be thinned because the materials are able to be selectively removed with respect to each other and exposed high-k.
In a similar, alternate embodiment herein referred to as “embodiment B”, the multi-layered stack is replaced by a single thick titanium nitride layer to allow a replacement metal gate structure having one doped and one undoped high-k gate oxide to be formed in a first and second transistor, respectively. The method uses a single layered blocking film, which may be initially thick and then later thinned. It is advantageous to have a thick layer when patterning using a soft mask. The patterning reveals the high-k material in a first FET which is to be doped and leaves the blocking stack on the second FET which is to remain undoped. After the soft mask patterning, the single layer blocking film is thinned by a controlled wet etch and a doping layer is formed everywhere. An anneal migrates dopant into the first high-k layer but the thinned blocking layer keeps the dopant away from the second FET's high-k layer. It is advantageous to have a thinned blocking layer during doping to prevent dissolved oxygen (which may have been in the upper portion of the thick blocking layer) from migrating to the high-k layer and adversely affecting Tivn (inverse of gate capacitance).
In a further embodiment herein referred to as “embodiment C” is, a substrate having a doped high-k in the first FET and an undoped high-k in the second FET region is made by a direct doping method. In this replacement gate integration scheme, in gate openings are formed in a dielectric layer over a first FET (future doped high-k FET) and a second FET (future undoped high-k FET). High-k layer(s) are formed in the openings. After words, a doping layer is formed directly on the high-k layer(s) followed by a multi-layered mask which is initially thick. The structure is patterned to remove the dopant and mask in the second FET region. The remaining mask on the first FET is thinned and an annealing stack is formed everywhere. An anneal migrates dopant into the high-k layer over the first FET region, but because there is no dopant layer above the second FET's high-k layer, it remains undoped. Subsequently, the annealing and doping stacks are removed and the work function metals are formed. Finally, the openings of the replacement metal gate first and second FETs are filled and planarized.
DETAILED DESCRIPTION
Indirect Doping
FIG. 1 is a flow chart of embodiments A and B of the present invention of making one doped and one undoped FET using a multi-layered blocking stack (embodiment A) or a single layer blocking stack (embodiment B) in a soft mask replacement metal gate process. In step 10 a substrate having an N-FET region and a P-FET region is provided. Over the substrate is a dielectric layer having two openings, which preferably were made by removing a dummy gate. These openings will be over the N-FET or P-FET region of the substrate and depending high-k integration scheme, may expose the substrate (“high-k last” integration scheme), may expose an interfacial layer in contact with the substrate (“high-k last” integration scheme), or may expose a high-k dielectric previously formed over the substrate (“high-k first” integration scheme). These openings will contain the future high-k, metal gates of the FETs.
Still referring to FIG. 1 , in step 20 , a high-k layer is formed in the openings in a high-k last integration scheme. If a high-k first scheme is practiced, forming the high-k is skipped. Thus, in a high-k last embodiment, the high-k layer lines the sidewalls and the bottom of the openings whereas in a high-k first embodiment the high-k is only at the bottom of the opening because the high-k material was formed with the dummy gate.
In step 25 , a blocking stack is formed over the substrate and the high-k layer. In embodiment A, a multi-layer blocking stack is used that will advantageously allow a blocking stack of different thicknesses to be formed and used during various steps in the process. Thus, as will explained later, the multi-layers allows the overall thickness of the blocking layer to be tuned depending upon the needs of that particular step of the process. The multi-layer approach, as will be shown later, also allows a thin blocking stack to be formed at some steps, thin stacks, without use of the multi-layer stack of this invention are which are often difficult to create. Alternatively, at step 25 in embodiment B, a single blocking layer (which is subsequently thinned) is formed rather than the multi-layered blocking stack.
Referring to step 30 of FIG. 1 , the blocking stact is lithographically patterned so that it is removed from a first FET region but remains on a second FET region. As will be explained later, it is during lithographic patterning that it is important to have a thick blocking layer
Referring to step 40 , a portion of the blocking stack in the second FET region is removed to leave a remaining, thin blocking layer in preparation for the anneal step in which a thin layer is advantageous, as will be explained later. In step 42 , a doping stack is formed everywhere including over the thinned blocking layer.
Referring to step 50 , an annealing stack is formed over both regions of the substrate and an anneal diffuses the dopant into the high-k layer of the unblocked first FET. Subsequently, in step 55 the annealing stack is removed. More layers, namely the doping stack and remaining thinned blocking layer, are removed in step 60 .
In step 70 , the work function metals are formed in the first and second FETs regions. Finally in step 90 , the openings having high-k and respective work function metals and are filled with a conductive material and planarized to yield a first FET having a doped high-k material and a second FET having an undoped high-k material. The embodiments of FIG. 1 will now be described in more detail in conjunction with FIGS. 2-12 .
FIG. 2 illustrates a structure which can represent a preliminary stage in the above described method, specifically, a cross-section of the substrate at the end of step 10 . As illustrated in FIG. 1 , is a semiconductor substrate 100 which may be a bulk single crystalline substrate a semiconductor on insulator substrate. The substrate 100 may be planar or have fins. The substrate has a first FET region 101 and second FET region 102 . In some embodiments the first region 101 may be include active semiconductor region in which an n-type field effect transistor (“NFET”) is to be formed, while in some embodiments the second region 102 may include a second active semiconductor region in which a p-type field effect transistor (“PFET”) is to be formed. In other embodiments both regions contain the same type of FET (e.g. both NFET or both PFET). An isolation region may separate the first and second FET regions, but is omitted from the figures for simplicity purposes.
Continuing with FIG. 2 , overlying the substrate 100 is dielectric layer 105 . The dielectric layer may be a single composition or may include multitude of different dielectric materials and layers. In the dielectric layer are at least two openings over the first and second FET regions of the substrate. Here, in a version of a high-k last integration scheme, the openings reveal a previously formed interfacial layer 112 . The interfacial layer may contain silicon and at least one of oxygen and nitrogen. In the substrate, on either side of the opening will be previously formed source (S) and drain (D) regions of the FETs. The source and drain regions may be, embedded in the substrate, raised from the substrate or both. The source and drain regions may or may not have silicide on them at this point in the process.
Thereafter, as shown in FIG. 3 's high-k last embodiment, a high-k layer 115 can be formed overlying the interfacial layer 112 and in the first and second openings 110 - 1 and 110 - 2 . Alternatively, interfacial layer 112 can be removed, and a new interfacial layer formed and/or high-k layer 115 can be formed in place of such layer. In one embodiment, the high-k layer 115 may include a high dielectric material having a dielectric constant greater than silicon dioxide and more preferably greater than silicon nitride. For example, the high-k layer 115 may include one or more of the following dielectric materials: hafnium oxide, hafnium silicon oxide, lanthanum oxide, lanthanum aluminum oxide, zirconium oxide, zirconium silicon oxide, titanium oxide, tantalum oxide, barium strontium titanium oxide, barium titanium oxide, strontium titanium oxide, yttrium oxide, aluminum oxide, lead scandium tantalum oxide, and lead zinc niobate. Typically, such layer may be deposited by chemical vapor deposition (CVD) or atomic layer deposition (ALD). The high-k layer 115 typically deposits onto all exposed surfaces, including lining the openings 110 - 1 , 110 - 2 and overlying the first and second FET regions 101 , 102 , and onto the interfacial layer 112 , when present within the gate openings.
Subsequently, as illustrated in FIG. 4 in accordance with an option of step 20 , a multi-layered blocking layer 120 is formed over the substrate. The blocking layer includes three layers a first bottom blocking layer (A), a second middle blocking layer (B), and a third top blocking (C). In a preferred embodiment the first (bottom—A) and third (top—C) blocking layers may be titanium nitride while the second (middle—C) blocking layer is a lanthanum (La) containing material such as La or lanthanum oxide. As formed, the first (bottom—A) blocking layer may be from about 15 angstroms to 25 angstroms and ranges there between; the second (middle—B) blocking layer may be from about 5 angstroms to 15 angstroms and ranges there between; and the third (top—C) blocking layer may be from about 5 angstroms to 30 angstroms and ranges there between.
Alternatively, in accordance with embodiment B, the blocking layer 120 may be a single layer of titanium nitride which is thick enough to protect the substrate in the subsequent patterning steps. Preferably the single, thick blocking layer equal to or greater than about 25 angstroms.
Continuing with FIG. 4 , a soft mask lithographic material 130 has been patterned over the substrate. Soft mask lithographic material may include one or more of the following: photoresist, an antireflective coating and an optical planarization layer (OPL) and preferably does not include a hard mask layer such as silicon dioxide or a metal hard mask. If the blocking layer were a single thin titanium nitride layer, the reactive ion etching process used to pattern the OPL would interact with the underlying high-k material of the unblocked gate (which in a future step will received a dopant to become a doped high-k FET, here the first FET) causing an increase in the interfacial layer 112 thickness which, in turn, undesirably increases the Tinv (inverse of gate capacitance). To solve this problem, in embodiment A a multi-layer blocking stack of step 20 is used whereas embodiment B uses a single thick TiN layer. As will be seen later, in each embodiment the blocking later can be later thinned. This allows the blocking layer to be initially thick to protect the high-k 115 and interfacial layers 112 during patterning of the lithographic material and later thinned which is advantageous for the dopant drive-in anneal.
Continuing with FIG. 4 and transitioning to FIG. 5 , after the lithographic patterning (shown in FIG. 4 ) the original blocking layer 120 has fulfilled one of its purposes (protecting the substrate during patterning) and can now be thinned in order to prepare itself for its next purpose, namely to act a thin dopant diffusion barrier layer. First, with the lithographic material 130 patterned to expose the first FET region 101 of the substrate 100 , the blocking layer 120 is removed from the first FET region 101 leaving the high-k layer 115 exposed in the first FET region 101 as depicted in FIG. 5
Continuing with FIG. 5 and transitioning to FIG. 6 , the lithographic material 130 is removed from the second FET region 102 . Now, in accordance with embodiment A, the multi-layer blocking stack 120 may be thinned by removing the top two layers, namely third (top) blocking layer 120 C (titanium nitride in a preferred embodiment) and second (middle) blocking layer 120 B (a lanthanum containing layer in a preferred embodiment), thereby leaving the first (bottom) blocking layer 120 A (titanium nitride) over the second FET region 102 of the substrate. The remaining first blocking layer 120 A may now serve as a dopant diffusion barrier in subsequent steps. The thickness of the remaining blocking layer may be from about 15 angstroms to about 25 angstroms and ranges there between.
The thinning of embodiment A's multi-layer blocking 120 stack which takes place can occur because of the unexpected finding that the middle blocking layer 120 B (preferably a La containing material) will etch readily in a hot peroxide solution when it is on silicon, but is etch resistant to the same chemistry when it is on titanium nitride (as in the preferred embodiment). By taking advantage of this unexpected phenomenon the multi-layer blocking stack is able to be both thick (when protecting the first FET region during OPL patterning) and thinned when functioning as a dopant barrier. Accordingly, a series of selective etches may be used to thin the blocking layer. For example, the top blocking layer 120 C may be etched in peroxide while the middle blocking layer 120 B is not etched (i.e. selective removal of the TiN relative to the middle layer sacrificial layer). Then the middle blocking layer 120 B may be removed with chloride containing chemistry selectively with respect to the bottom blocking layer 120 A to leave the thinned blocking layer 120 A.
Turning to embodiment B, if the blocking layer remained a single thick titanium nitride layer then during a subsequent anneal, the inventors have discovered that dissolved oxygen in the titanium nitride may undesirably enter the high-k layer of the undoped FET (FET with blocking material overlying it, here, the second FET). There are two possible solutions of the dissolved oxygen problem of the single thick blocking layer. One is to use a silicon dioxide hard mask to prevent oxygen from entering the TiN blocking film. However, the hard mask approach is undesirable because after patterning, HF is used to remove the hard mask. HF will attack the high-k 115 layer. Another solution is to thin the single thick blocking layer thus removing the upper portions of the layer which contain the oxygen. Unfortunately, it can be difficult to reliably and repeatedly thin a single, thick TiN layer to thicknesses required during the anneal process. However, as practiced in embodiment B, the inventors have found a repeatable and controllable process (5-10 Angstrom/min removal rate and ranges there between) to achieve such thinning. Specifically, a titanium nitride blocking film can be etched in a solution of room temperature or colder aqueous ammonia hydroxide and an aqueous hydrogen peroxide (SC1) having 50:1.5 ratio. Note that a thinned remaining block layer will be referred to as 120 A regardless if it is a remaining portion of a multi-layer stack or an initially thicker single layer blocking stack.
Turning to FIG. 7 , a dopant film stack 140 is formed over the entire surface of the substrate. Thus, the dopant film stack lines the first FET region 101 opening 110 - 1 and is on the high-k layer 115 in the first opening. Meanwhile, in the second FET region 102 , the dopant film stack 140 is over the remaining thinned blocking layer, namely the first (bottom) blocking layer 120 A. In an embodiment in which the first FET region 101 is an NFET, the dopant stack may contain lanthanum, for example as elemental lanthanum or an oxide, or an n-dopant stack may contain some other rare earth dopant such as ytrrium which shifts the effective work function towards the conduction band-edge. The thickness of the dopant stack may be from about 1 Å to about 10 Å and ranges therebetween.
Referring to FIG. 8 , in addition to a dopant stack 140 , and annealing stack 142 may be placed on top of the dopant stack 140 . In a preferred embodiment, the annealing stack 142 may have a bottom layer, a cap titanium nitride layer, followed by an amorphous silicon layer. The amorphous silicon layer function to block oxygen from reaching the high-k during the anneal which would adversely impact Tinv (increase). The cap titanium nitride layer functions to prevent the silicon from forming a silicide with the high-k layer 115 and/or dopant layer.
Still referring to FIG. 8 , with the dopant stack 140 and annealing stacks 142 in place, the substrate 100 is annealed to drive the dopant into the high-k 115 of the first FET region 101 . The anneal may be from about 800 C to about 1300 C and ranges therebetween. If the temperature is too low the dopants will not diffuse sufficiently into the high-k material 115 and there will be no shift in the threshold voltage of the first FET. If the temperature is too high, too much dopant moves close to the substrate 100 causing a change in crystallization of the high-k material which may lead to severe gate leakage. The anneal may be performed by a soak anneal (several seconds), spike/rapid thermal anneal (RTA) which is a few seconds, or a laser anneal (LSA) which is milliseconds. Typically, the anneal is performed in inert ambient such as nitrogen and/or argon.
Still referring to FIG. 8 , the substrate 100 is shown after the anneal. Here, the dopant has moved into the high-k layer of the first region 101 to become the doped high-k 145 . Preferably the dopant in the high-k is concentrated near the interfacial layer/high-k interface. Also, FIG. 8 a similar cross-hatching as the doped high-k 145 indicates that the top of the thinned, remaining blocking layer 120 A may also absorb some dopant, but note that the dopant does not reach the high-k 115 in the second FET regions 102 which remains undoped.
Turning to FIG. 9 , annealing stack 142 , dopant stack 140 and the remaining thinned blocking layer 120 A are removed. Removal is by a sequence of wets processes, typically involving ammonia based chemistry to remove silicon, peroxide and HCl and ammonia based chemistries (SC1, SC2) to remove the TiN and the dopant materials. Choice of chemistry is motivated by efficiency in removing these materials while retaining high selectivity to the high-k materials (doped 145 and undoped 115 ). Thus, FIG. 8 shows a doped high-k 145 in the first FET region 101 , while the high-k 115 in the second FET region 102 remains undoped.
Referring to FIG. 10 , a first work function metal stack 150 is formed everywhere and then patterned so that it only remains over the first FET region 101 , including the doped high-k 145 . In one embodiment, the first and second FET regions, 101 and 102 , may be an opposite type FETs. Therefore, in an embodiment in which the first FET region 101 is an N-FET, the first work function metal stack may include one or more of a titanium nitride film and a film containing one or more of the following elements: titanium, aluminum and carbon to form a metallic film. The work function stack may include underlying barrier and/or overlying capping layers in addition to work function adjustment material.
Referring to FIG. 11 , a further stage of fabrication in which a second work function metal stack 160 suitable for setting a workfunction for the second FET region 102 , is formed everywhere. As shown in FIG. 11 , the second work function stack 160 remains everywhere, but in an alternate embodiment, the second work function stack 160 may be patterned so it remains only in the second FET region 102 (a P-FET, continuing with the example from above). With respect to a P-FET example, suitable work function stack materials may include one or more layers of titanium nitride.
The preceding work function metal formation formed the first, here N-FET work function materials prior to the second work function metals, here P-FET. However, the order could be reversed as will be shown in conjunction with another embodiment.
Thereafter, referring to FIG. 12 , further processing can be performed to complete the gates of the NFET and the PFET. Specifically, a fill stack 170 is formed in the openings and planarized. Fill stack 170 may include several layers including a metal seal layer, a wetting layer, and a seed layer and a bulk fill layer can be deposited. Not every layer is needed in all cases. In one embodiment, the wetting layer may be titanium nitride and the bulk fill layer can be tungsten. Specifically, in the example illustrated in FIG. 12 , the second work function metal 160 serves two roles: it is a work function metal of the second FET region 102 and wetting layer prior to bulk fill of both FET regions 101 and 102 .
Direct Doping Using Multi-Layered Mask
FIG. 13 is a flow chart of a method of making one doped and one undoped FET using a multi-layered mask. In step 10 a substrate having an N-FET region and a P-FET region is provided. Over the substrate is a dielectric layer having two openings, which preferably were made by removing a dummy gate. These openings will be over the N-FET or P-FET region of the substrate and depending high-k integration scheme, may expose the substrate (“high-k last” integration scheme), may expose an interfacial layer in contact with the substrate (“high-k last” integration scheme), or may expose a high-k dielectric previously formed over the substrate (“high-k first” integration scheme). These openings will contain the future high-k, metal gates of the FETs. The substrate may be planar or have fins.
Still referring to FIG. 13 , in step 20 , a high-k layer is formed in the openings in a high-k last integration scheme. If a high-k first scheme is practiced, forming the high-k is skipped. Thus, in a high-k last embodiment, the high-k layer lines the sidewalls and the bottom of the openings whereas in a high-k first embodiment the high-k is only at the bottom of the opening because the high-k material was formed with the dummy gate. In step 22 , a doping layer is formed on the high-k material.
In step 25 , a mask is formed over the substrate and the high-k layer. In one embodiment, a multi-layer mask is used that will advantageously allow a mask of different thicknesses to be formed and used during various steps in the process. Thus, as will explained later, the multi-layers allows the overall thickness of the hard mask layer to be tuned depending upon the needs of that particular step of the process. The multi-layer approach, as will be shown later, also allows a thin mask to be formed at some steps, thin stacks, without use of the multi-layer stack of this invention are often difficult to create.
Referring to step 30 of FIG. 13 , the mask is lithographically patterned so that it is removed from a second FET region but remains on a first FET region. As will be explained later, it is during lithographic patterning that it is important to have a thick mask.
Referring to step 40 , a portion of the mask in the first FET region is removed to leave a remaining, thin mask layer in preparation for the anneal step.
Referring to step 50 , an annealing stack is formed over both regions of the substrate and an anneal diffuses the dopant into the high-k layer of the unblocked first FET. Subsequently, in step 55 the annealing stack is removed. More layers, namely the doping stack and remaining thinned hard mask layer, are removed in step 60 .
In step 70 , the work function metals are formed in the first and second FETs regions. Finally in step 90 , the openings having high-k and respective work function metals and are filled with a conductive material and planarized to yield a first FET having a doped high-k material and a second FET having an undoped high-k material. The embodiments of FIG. 13 will now be described in more detail in conjunction with FIGS. 2-14 .
FIG. 14 illustrates a structure which can represent a preliminary stage in the above described method, specifically, a cross-section of the substrate at the end of step 10 . As illustrated in FIG. 13 , is a semiconductor substrate 100 which may be a bulk single crystalline substrate a semiconductor on insulator substrate. The substrate 100 may be planar or have fins. The substrate has a first FET region 101 and second FET region 102 . In some embodiments the first region 101 may be include active semiconductor region in which an n-type field effect transistor (“NFET”) is to be formed, while in some embodiments the second region 102 may include a second active semiconductor region in which a p-type field effect transistor (“PFET”) is to be formed. In other embodiments both regions contain the same type of FET (e.g. both NFET or both PFET). An isolation region may separate the first and second FET regions, but is omitted from the figures for simplicity purposes.
Continuing with FIG. 14 , overlying the substrate 100 is dielectric layer 105 . The dielectric layer may be a single composition or may include multitude of different dielectric materials and layers. In the dielectric layer are at least two openings over the first and second FET regions of the substrate. Here, a version of a high-k last integration scheme is illustrated, the openings reveal a previously formed interfacial layer 112 . The interfacial layer may contain silicon and at least one of oxygen and nitrogen. In the substrate, on either side of the opening will be previously formed source (S) and drain (D) regions of the FETs. The source and drain regions may be, embedded in the substrate, raised from the substrate or both. The source and drain regions may or may not have silicide on them at this point in the process.
Thereafter, as shown in FIG. 15 's high-k last embodiment, a high-k layer 115 can be formed overlying the interfacial layer 112 and in the first and second openings 110 - 1 and 110 - 2 . Alternatively, interfacial layer 112 can be removed, and a new interfacial layer formed and/or high-k layer 115 can be formed in place of such layer. In one embodiment, the high-k layer 115 may include a high dielectric material having a dielectric constant greater than silicon dioxide and more preferably greater than silicon nitride. For example, the high-k layer 115 may include one or more of the following dielectric materials: hafnium oxide, hafnium silicon oxide, lanthanum oxide, lanthanum aluminum oxide, zirconium oxide, zirconium silicon oxide, titanium oxide, tantalum oxide, barium strontium titanium oxide, barium titanium oxide, strontium titanium oxide, yttrium oxide, aluminum oxide, lead scandium tantalum oxide, and lead zinc niobate. The layer may be deposited by chemical vapor deposition (CVD) or atomic layer deposition (ALD). The high-k layer 115 may form on all exposed surfaces, including lining the openings 110 - 1 , 110 - 2 and overlying the first and second FET regions 101 , 102 , and on the interfacial layer 112 , when present within the gate openings.
Referring to FIG. 16 , a doping layer 140 is formed over the substrate. In an embodiment in which the first FET region 101 is an NFET, the dopant stack may contain lanthanum, for example as elemental lanthanum or an oxide, or an n-dopant stack may contain some other rare earth dopant such as yttrium which shifts the effective work function towards the conduction band-edge. The thickness of the dopant stack may be from about 1 Å to about 10 Å and ranges therebetween. In an embodiment in which the first FET region 101 is PFET, the dopant may include aluminum.
Subsequently, as illustrated in FIG. 17 , a multi-layered mask 120 is formed over the substrate. For simplicity, in FIG. 17 , the mask 120 is shown in one large layer, however, the mask is multi-layered and includes three layers a first bottom mask layer, a second middle mask layer, and a third top mask (one may also refer to FIG. 4 , for an example in which a multi-layer structure is explicitly shown and is also appropriate in the present embodiment). In a preferred embodiment the first (bottom) and third (top) mask layers may be titanium nitride while the second (middle) mask layer is a lanthanum (La) containing material such as La or lanthanum oxide. As formed, the first (bottom) mask layer may be from about 15 Å to 25 Å and ranges there between; the second (middle) mask layer may be from about 5Å to 15 Å and ranges there between; and the third (top) mask layer may be from about 5 Å to 30 Å and ranges there between.
Referring to FIG. 18 , a lithographic material 130 has been patterned over the substrate. The lithographic material may include one or more of the following: photoresist, an antireflective coating and an optical planarization layer (OPL) and preferably does not include a mask layer such as silicon dioxide or a metal mask. Thus, the lithographic material 130 is preferably a stack of soft-mask materials. In a preferred embodiment, the OPL layer is directly on top of the multi-layered mask.
In the present invention, under the soft mask lithographic material 130 , is the previously deposited multi-layer layer mask 120 . If the mask layer 120 were a single thin titanium nitride layer (for example, less than 15 Å), the reactive ion etching process used to pattern the OPL would interact with the underlying high-k material (particularly on the second FET region 102 in which there is no intervening dopant layer 140 ) causing an increase in the interfacial layer 112 thickness which, in turn, undesirably increases the Tinv (inverse of gate capacitance). To reduce the interaction of the soft mask removal and gate dielectric degradation, the current invention employs a multi-layer mask between the soft mask lithographic materials and the high-k. As will be seen later, the mask later can be later thinned. This allows the mask layer to be initially thick to protect the high-k 115 and interfacial layers 112 during patterning of the lithographic material and later thinned which is advantageous for the dopant drive-in anneal.
Continuing with FIG. 18 and transitioning to FIG. 19 , after patterning the lithographic materials 130 in FIG. 18 , the original multi-layer mask layer 120 has fulfilled one of its purposes (protecting the substrate during patterning) and can now be thinned in preparation for the subsequent high-k and dopant drive in anneal. First, with the lithographic material 130 patterned to expose the second FET region 102 of the substrate 100 , the multi-layer mask layer 120 is removed from the second FET region 102 leaving the high-k layer 115 exposed in the second FET region 102 as depicted in FIG. 19
Continuing with FIG. 19 and transitioning to FIG. 20 , the patterned lithographic material 130 is removed from the first FET region 101 . Now, in accordance with one embodiment, the multi-layer mask 120 in the first FET region 101 may be thinned by removing the top two layers, namely third (top) mask layer (titanium nitride in a preferred embodiment) and second (middle) mask layer (a lanthanum containing layer in a preferred embodiment), thereby leaving the first (bottom) mask layer (titanium nitride in a preferred embodiment) over the first FET region 101 of the substrate. The remaining portion of the multi-layer hardmask will now be referred to as reference numeral 120 A and is the first (bottom) layer of the original multi-layered hardmask. The thickness of the remaining mask layer 120 A may be from about 15 angstroms to about 25 angstroms and ranges there between.
The thinning of the multi-layer mask 120 stack which takes place can occur because of the unexpected finding that the middle mask layer 120 (preferably a La containing material) will etch readily in a hot peroxide solution when it is on silicon, but is etch resistant to the same chemistry when it is on titanium nitride (as in the preferred embodiment). Thus, the top mask layer can be removed selective to the middle by using the hot peroxide solution. Then the middle mask layer can be removed selective to the bottom mask layer using a chlorine containing acid. By taking advantage of this unexpected phenomenon the multi-layer mask is able to be both thick (when protecting the first FET region during OPL patterning) and later thinned.
A multi-layered hardmask 120 which is subsequently thinned, is preferable to an original single thick titanium nitride mask layer because a single thick TiN layer has dissolved oxygen which accumulates due to the lithographic patterning and removal. During a subsequent anneal, the dissolved oxygen present in the titanium nitride may undesirably enter the high-k layer of the FET with mask material overlying it (here, the first FET). To solve the dissolved oxygen problem of the single thick mask layer, a silicon dioxide mask over the TiN may be used to prevent oxygen from entering the TiN mask film. However, the silicon dioxide mask approach is undesirable because after patterning, HF is used to remove silicon dioxide mask. HF will also attack the high-k 115 layer. Another solution of the dissolved oxygen in single thick TiN layer is to thin the single thick mask layer thus removing the upper portions of the layer which contain the oxygen. Unfortunately, it can be difficult to reliably and repeatedly thin a single, thick TiN layer. Thus, the solution of the present invention, using a multi-layered hardmask solves the dissolved oxygen problem, does not require an HF etch (thus preserving the high-k) and allows controllable removal of the multi-layered mask.
Referring to FIG. 21 , an annealing stack 142 may be placed on top of the substrate. In particular, the annealing stack 142 is on the thinned layer 120 A in the first FET region 101 and on the high-k 115 in the second FET region 102 . In a preferred embodiment, the annealing stack 142 may have a bottom layer which may be referred to as a cap titanium nitride layer, followed by an amorphous silicon layer. The amorphous silicon layer function to block oxygen from reaching the high-k during the anneal which would adversely impact Tinv (increase). The cap titanium nitride layer functions to prevent the silicon from forming a silicide with the high-k layer 115 in the second FET region 102 .
Referring to FIG. 22 , with the dopant stack 140 and annealing stacks 142 in place, the substrate 100 is annealed to drive the dopant into the high-k 115 of the first FET region 101 . The anneal may be from about 800 C to about 1300 C and ranges therebetween. If the temperature is too low the dopants will not diffuse sufficiently into the high-k material 115 and there will be no shift in the threshold voltage of the first FET. If the temperature is too high, too much dopant moves close to the substrate 100 causing a change in crystallization of the high-k material which may lead to severe gate leakage. The anneal may be performed by a soak anneal (several seconds), spike/rapid thermal anneal (RTA) which is a few seconds, or a laser anneal (LSA) which is milliseconds. Typically, the anneal is performed in inert ambient such as nitrogen and/or argon.
Still referring to FIG. 22 , the substrate 100 is shown after the anneal. Here, the dopant has moved into the high-k layer of the first region 101 to become the doped high-k 145 . Preferably the dopant in the high-k is concentrated near the interfacial layer/high-k interface. In the second FET regions 102 , the high-k 115 remains undoped because the dopant layer was previously patterned and removed above the second FET region 102 .
Turning to FIG. 23 , annealing stack 142 , dopant stack 140 and the remaining thinned mask layer 120 A are removed. Removal is by a sequence of wets processes, typically involving ammonia based chemistry to remove silicon, peroxide and HCl and ammonia based chemistries (SC1, SC2) to remove the TiN and the dopant materials. Choice of chemistry is motivated by efficiency in removing these materials while retaining high selectivity to the high-k materials (doped 145 and undoped 115 ). Thus, FIG. 23 shows a doped high-k 145 in the first FET region 101 , while the high-k 115 in the second FET region 102 remains undoped.
Referring to FIG. 24 , a first work function metal stack 150 is formed everywhere and then patterned so that it only remains over the first FET region 101 , including the doped high-k 145 . In one embodiment, the first and second FET regions, 101 and 102 , may be an opposite type FETs. Therefore, in an embodiment in which the first FET region 101 is an N-FET, the first work function metal stack may include one or more of a titanium nitride film and a film containing one or more of the following elements: titanium, aluminum and carbon to form a metallic film. The work function stack may include underlying barrier and/or overlying capping layers in addition to work function adjustment material.
Referring to FIG. 25 , a further stage of fabrication in which a second work function metal stack 160 suitable for setting a workfunction for the second FET region 102 , is formed everywhere. As shown in the embodiment of FIG. 13 , the second work function metal stack remains in both the first and second FET regions, 101 and 102 , respectively, however, alternate embodiments may remove the second work function 160 metal stack from the first FET region 101 . When the second FET region 102 is a P-FET, suitable second work function stack 160 materials may include one or more layers of titanium nitride.
The preceding work function metal formation formed the first, here N-FET work function materials prior to the second work function metals, here P-FET. However, the order could be reversed.
Thereafter, referring to FIG. 26 , further processing can be performed to complete the gates of the NFET and the PFET. Specifically, a fill stack 170 is formed in the openings and planarized. Fill stack 170 may include several layers including a metal seal layer, a wetting layer, and a seed layer and a bulk fill layer can be deposited. Not every layer is needed in all cases. In one embodiment, the wetting layer may be titanium nitride and the bulk fill layer can be tungsten. Specifically, in the example illustrated in FIG. 14 , the second work function metal 160 serves two roles: it is a work function metal of the second FET region 102 and wetting layer prior to bulk fill of both FET regions 101 and 102 .
While the invention of making doped and undoped FETs with a multi-layer mask has been described in accordance with certain preferred embodiments thereof, those skilled in the art will understand the many modifications and enhancements which can be made thereto without departing from the true scope and spirit of the invention, which is limited only by the claims appended below. | A method of fabricating advanced node field effect transistors using a replacement metal gate process. The method includes dopant a high-k dielectric directly or indirectly by using layers composed of multi-layer thin film stacks, or in other embodiments, by a single blocking layer. By taking advantage of unexpected etch selectivity of the multi-layer stack or the controlled etch process of a single layer stack, etch damage to the high-k may be avoided and work function metal thicknesses can be tightly controlled which in turn allows field effect transistors with low Tinv (inverse of gate capacitance) mismatch. | 7 |
OBJECT OF THE INVENTION
[0001] The present invention consists of a formulation of natural triterpenes and biophenols obtained from the genus Olea in liposomes, specifically of triterpenes from the group comprised of maslinic acid and/or its salts, oleanolic acid and/or its salts, tyrosol and hydroxytyrosol in liposomes.
STATE OF THE ART
[0002]
Oleanolic Acid
[0003] Oleanolic acid (3-beta-hydroxy-28-carboxy-oleanene) is a triterpenic acid ubiquitously distributed within the plant kingdom. Thus, the phytochemical database of the United States Department of Agriculture (Internet Address http://www.ars-grin.gov:8080/npgspub/xsql/duke/chemdisp.xsql?chemical=OLEANOLIC-ACID) is present in 130 plants, one of which is Olea europaea , and moreover a number of proven biological activities (abortifacient, anti-cariogenic, antifertility, antihepatotoxic, anti-inflammatory, anti-sarcomic, cancer-preventive, cardiotonic, diuretic, hepatoprotective, uterotonic, etc., up to 38 different properties). Numerous studies have been published on the possible biological activity of this acid and its glucosides. It has been studied in its activity as an inhibitor of the proliferation of leukaemia cells (Essady, D., Najid, A., Simo, A., Denizot, Y., Chulia, A. J. and Delage, C.; Mediators of Inflammation (1994) 3, 181-184), as a hypoglycemiant (Yoshikawa, M., Matsuda, H., Harada, E., Mukarami, T., Wariishi, N., Murakami, N. And Yamahara, J.; Chemical & Pharmaceutical Bulletin, (1994) 42, 1354-1356) an antitumoral (Ohigashi, H., Mukarami, A. and Koshimizu, K ACS Symposium Series (1994) 547, 251-261), a producer of antagonistic effects in anaphylactic shock (Zhang, L. R. and Ma, T. X.; Acta Pharmacológica Sinica (1995)16, 527-530), hepatoprotective (Liu, J., Liu, Y. P., Parkinson, A. and Klaasen, C. D.; Journal of Pharmacology and Experimental Therapeutics, (1995) 275, 768-774; Connolly, J. D. and Hill, R. A. Natural Product Reports 12, 609-638 (1995), anti-inflammatory (Recio, M. D., Giner, R. M., Manez, S. And Rios, J. L.; Planta Medica (1995) 61, 182-185. A specific review of the pharmacological activity of oleanolic acid has been published (Liu, J. Journal of Ethnopharmacology (1995) 49, 57-68).
[0004] Other derivatives of oleanolic acid, in addition to echinocystic acid (16-hydroxy-oleanolic) have been found to have inhibiting effects against the replication of HIV in H-9 cells with EC50 values of 2.3 mM (Anti-AIDS agents, 21. Triterpenoid saponins as anti-HIV principles from fruits of Gleditsia japonica and Gymnocladus chinensis , and a structure-activity correlation, Konoshima, Takao; Yasuda, Ichiro; Kashiwada, Yoshiki; Cosentino, L. Mark; Lee, Kuo-Hsiung, J. Nat. Prod., 58(9), 1372-7, (1995)). Other many direct derivatives have been found to be Leukotriene D4 antagonists (Leukotriene D4 antagonists in Tripterygium wilfordii , Morota, Takashi; Saitoh, Kazuko; Maruno, Masao; Yang, Chun-Xin; Qin, Wan-Zhang; Yang, Bing-Hui, Nat. Med., 49(4), 468-71 (1995)).
[0005] The best proof of the interest that it arouses worldwide is the number of international patents that exist in relation to this acid: Use of oleanolic acid as a vasodilator and restorer agent for endothelial dysfunction (WO2004ES00190 20040430); Cosmetic and dermopharmaceutical compositions for skin prone to acne (WO2002FR03344 20021001); Cosmetic composition for care of sensitive skin includes oleanolic acid or vegetable extract rich in oleanolic acid, and at least one other vegetable extract chosen from shea-butter flower and solanum lycocarpum (FR20000008758 20000705); Process for preparing food products fortified with oleanolic acid (US19990468637 19991222); Oleanolic acid-based anti-pruritus agent (JP19970183075 19970623); Angiogenesis inhibitor composition comprising oleanolic acid (KR19920021117 19921111).
[0000]
Maslinic Acid
[0006] Maslinic acid (2-alpha, 3-beta-dihydroxy-28-carboxy-oleanene), also known as crataegolic acid, is far less widespread in nature, and has been found in 23 plants (Internet Address http://www.ars-grin.gov:8080/npgspub/xsql/duke/chemdisp.xsql?chemical=MASLINIC-ACID). It is known to have antihistaminic and anti-inflammatory properties (Internet Address http://www.ars-grin.gov:8080/npgspub/xsql/duke/chemdisp.xsql?chemical=MASLINIC-ACID) although it has not been extensively studied because of its scarcity. The isolation of oleanolic and maslinic acids from waxes on the surface of the fruit of Olea europaea has been described (Bianchi, G., Pozzi, N. And Vlahov, G. Phytochemistry (1994) 37, 205-207) by means of methanol extraction from olives previously washed with chloroform. The separation of acids of this type has been described by means of high-speed counter-flow chromatography (HSCCC)(Du, Q. Z., Xiong, X. P. and Ito, Y.; Journal of Liquid Chromatography (1995) 18, 1997-2004.
[0007] Maslinic acid has recently been found to have a powerful inhibiting activity in vitro of the Aids virus protease (HIV-1) (Anti-HIV Triterpene Acids from Geum japonicum , Xu, H. X.; Zeng, F.; Wan, M.; Sim, Keng-Yeow J. Nat. Prod., 59(7), 643-645 (1996)). It is also a product of the future, as revealed by a pharmacophore search for HIV-1 protease inhibitors, performed by the National Cancer Institute (Betsheda, USA), which has pinpointed a by-product of maslinic acid as a promising basis for future development in this activity (Discovery of Novel, Non-Peptide HIV-1 Protease Inhibitors by Pharmacophore Searching, Wang, Shaomeng; Milne, G. W. A.; Yan, Xinjian; Posey, Isadora; Nicklaus, Marc C.; GrahamX Lisa; Rice, William G., J. Med. Chem., 39(10), 2047-54 (1996)).
[0008] As a result of the biological tests performed by the University of Granada to date, alone or in collaboration with other Universities or Research centres, two patents have been filed relative to the production of medicines as protease inhibitors for the treatment of illnesses produced by protozoa of the genus Cryptosporidium (P9701029 Use of maslinic acid as a serine protease inhibitor for the treatment of illnesses caused by parasites of the genus Cryptosporidium ). In addition, clinical trials using MDCK cell lines show an infection inhibition percentage of 92.3% at 37 mg/mL. In the case of AIDS-causing viruses, the tests have resulted in a patent (P9702528 Use of maslinic acid as a protease inhibitor for the treatment of the illness caused by the acquired immunodeficiency virus), as it has been found to act intracellularly and considerably inhibits the exit of the virus from the infected cell towards the medium, a mechanism that seems to work with the use of serine proteases. More recently, the Departments of Pharmacology and Organic Chemistry of the University of Granada have carried out a study on hepatoprotection with magnificent results, included in the publication “Antioxidant Activity of Maslinic Acid, a Triterpene obtained from Olea europaea ” M. Pilar Montilla, Ahmad Agil, M. Concepción Navarro, M. Isabel Jiménez, Andrés Garcia-Granados, Andrés Parra and Matilde Cabo, Planta Medica 2003, 69, 472-474, which revealed that maslinic acid reduces lipoperoxide levels and membrane hepatocyte susceptibility to lipid peroxidation (LPO), thereby producing a resistance to oxidative stress in rats. On the other hand, researchers from the Universities of Granada and Jaén have performed detailed experiments on rainbow trout, demonstrating that the additivation of specific amounts of maslinic acid to their feed results in a significant improvement of the hepatic organ and function and, therefore, of the animal's health. All of these results have been included in the patent titled by the University of Granada “Maslinic acid as an additive in animal production, P200401679”.
[0009] As in the case of the aforementioned oleanolic acid, the growing interest in this product is obvious in the large number of patents filed in which maslinic acid acts as an active component: Antitumor agent US20030355201 20030131; Apoptosis inductor (WO2002JP13663 20021226); Antiobestic foods and drinks (WO2002JP11608 20021107); External agent for the skin and whitening agent (US20020259323 20020930); Antiobesity drugs and materials thereof (WO2002JP07709 20020730); Drugs for vascular lesion (WO2002JP03189 20020329); Antitumor food or beverage (WO2001 JP 1374 20011225).
[0010] Special attention must also be given to another olive component, 3.4-dihydroxyphenyl ethanol (hydroxytyrosol), on which there exist more than 60 patents aimed at protecting highly varied production processes. Thus, researchers from the University of Granada developed in 1992 a “Method of use of alpechin for the production of acids, phenols, alcohols and derivatives by means of counter-flow processes” (Spanish Patent application: 9298236), a process fundamentally aimed at the use of hydroxytyrosol based on alpechin from olives, obtained by means of the three-phase process, although applicable to the aqueous part contained in the “alpeorujo”. This process, which consists of the concentration of vegetation water, de-oiled from the extract, subsequent extraction with ethyl acetate and separation of the contents of this extract by means of chromatography-based processes allowed the high-purity isolation of the biophenols present in this extract (fundamentally tyrosol and hydroxytyrosol). Afterwards, the University of Granada developed and patented a process for the production of mannitol from these same derivatives (Use of olive branches and leaves and peduncles and olive alpechin for the production of mannitol and derivatives, P9300490), (Process for the production of mannitol and by-products from the “alpeorujo” resulting from two-phase olive processing, P9300945). On consolidating the milling process to the so-called two-phase process (without added water), new works have arisen aimed at the isolation of hydroxytyrosol: [ Production in Large Quantities of Highly Purified Hydroxytyrosol from Liquid-Solid Waste of Two - Phase Olive Oil Processing or “alpeorujo ” by Juan Fernández-Bolaños, Guillermo Rodriguez, Rocio Rodriguez, Antonia Heredia, Rafael Guillén, and Ana Jiménez, Agric. Food Chem., 50 (23), 6804 -6811(2002)], having patented different processes: Method of obtaining a hydroxytyrosol-rich composition from vegetation water (Spanish Patent P200100346) (PCT/ES02/00058). Methods for isolating hydroxytyrosol concentrates from pitted olives have also been developed, treating the vegetation waters with citric acid and subsequently incubating, for the purpose of obtaining the hydroxytyrosol concentrate without solvents (U.S. Pat. Nos. 6,197,308 and 6,165,475).
[0011] Hydroxytyrosol concentrates are marketed with the names Hidrox® (Internet Address http://www.creagri.com/hidrox/proprietary.html) and related products “Method of obtaining a hydroxytyrosol-rich composition from vegetation water” (U.S. Pat. No. 6,416,808) (Internet Address http://www.patentstorm.us/patents/6416808.html). In Spain, these are marketed with the name Hytolive® (Internet Address http://www.hytolive.com) (Internet Address http://www.nutraingredients.com/news/news.asp?id=38632) and in Portugal as Olidrox® (Internet Address http://www.cotecportugal.pt/cotec/images/pdf/Olidrox.pdf).
[0012] In addition to the process described in the patents with previous pitting, in the other isolation processes, the line of action consists of a hydrothermal treatment and provoking a prior hydrolysis of various natural components that structurally contain tyrosol and hydroxytyrosol, with or without catalysis, performing filtration processes with membranes and subsequently isolating these phenols in a greater or lesser degree of purity by separation with various types of exchange resins. On the other hand, a large quantity of processes have been developed for the isolation of antioxidants from olive leaves (for example, European Patent EP1389465).
[0013] The University of Granada has an industrial patent (P9601652, WO98/04331, Process for the industrial use of 3beta-hydroxy-olean-12-en-28-oic (oleanolic) acid and 2alpha,3beta-dihydroxy-olean-12-en-28-oic (maslinic) acid contained in the olive milling by-products), which allows the industrial production of these two acids, separately and in a high degree of purity, from solid by-products of industrial olive milling, by any of the currently used processes (presses, continuous in the three-phase and the so-called two-phase), which represents an attainable and practically inexhaustible source thereof.
[0014] In the industrial tuning of this patent, it has been possible to isolate, in an industrially profitable manner, a natural biophenol concentrate by means of processes very different to those described in the aforementioned patents. The process used is efficient and very low-cost, also bearing in mind that it relates to the use of a by-product from the general method used for the production of oleanolic and maslinic acids. For this purpose, the University of Granada has established a new process captured in patent application P200600536 titled “Process for the industrial use of Tyrosol and Hydroxytyrosol contained in the solid by-products of industrial olive milling”, due to which it is also available for the production and application of this range of biophenols for the production of functional foods, alone or combined with other natural olive components.
[0015] On the other hand, liposomes are spherical vesicles obtained from the interaction of phospholipids. Their formation is not spontaneous but rather induced by the presence of water.
[0016] Phospholipids are antipathic molecules, that is, they are comprised of two different parts, one of which is hydrophilic and the other hydrophobic. This characteristic of phospholipids is the cause, when dispersed in water, of the molecules becoming oriented in space, forming micellar structures known as liposomes. Liposomes are characterised by being spherical structures that contain the aqueous medium used for their dispersion.
[0017] Liposomes were initially used as cellular membrane models for biophysical studies due to their structural similarity to the cytoplasmatic membranes of most of the cells of living organisms. It was precisely this similarity which gave rise to the idea of their use as a method for transporting substances in topical and parenteral administration.
DESCRIPTION OF THE INVENTION
[0018] For the extraction of the triterpenes present in the composition with liposomes we can use, amongst other processes, that described in a patent developed and titled by the University of Granada (ES211498, Process for the industrial use of 3beta-hydroxy-olean-12-en-28-oic (oleanolic) acid and 2alpha,3beta-dihydroxy-olean-12-en-28-oic (maslinic) acid contained in olive milling by-products) which allows the industrial production of these two acids, separately and in high degree of purity, from solid by-products of industrial olive milling, by any of the currently used processes (presses, continuous in the three-phase and the so-called two-phase), which represents an attainable and practically inexhaustible source thereof. The separation process established is totally physical and extremely effective, allowing the two products to be isolated in the desired proportions from complex original mixtures. This allows us to obtain natural oleanolic and maslinic acid by recovering these from the previously milled olive; due to the extremely hydrophobic nature of these triterpenes, they are immediately associated to the hydrophobic part of the phospholipids, due to which their inclusion is simple and immediate. The amount of substance to be added is limited by the amount of phospholipids present in the liposomic dispersion.
[0019] For the extraction of biophenols (fundamentally hydroxytyrosol and tyrosol) present in the composition of liposomes, we can use, amongst other processes, that described in the patent application filed by the University of Granada (P200600536 titled “Process for the industrial use of Tyrosol and Hydroxytyrosol contained in the solid by-products of industrial olive milling”). As in the case of the aforementioned triterpenes, the separation process established is totally physical and extremely effective, allowing us to isolate these products in the desired proportions from the complex original mixtures. This allows us to obtain natural hydroxytyrosol and tyrosol, recovering these from the previously milled olive; due to the hydrophilic nature of the biophenols, they are immediately associated to the hydrophilic part of the biomembranes, due to which their inclusion is simple and immediate.
[0020] For the preparation of the formulation in liposomes, take a specific amount of spherical liposomes (not laminated), which are readily available on the market, and add the biophenols dissolved in a minimum amount of water. This hydrophilic composition is added, preferably hot and by stirring vigorously, to a hydrophobic base already containing the triterpenes.
[0021] This preparation method accepts from 0.0001% to 20% in weight of final product of the natural biophenols and triterpenes in liposomes.
[0022] Thus, we obtain a formulation of biophenols and triterpenes obtained from the genus Olea in liposomes, which is composed of at least one of the triterpenes of the group consisting of maslinic acid and oleanolic acid and/or their salts, and at least one of the biophenols of the group consisting of hydroxytyrosol and/or tyrosol and by liposomes. The biophenols and triterpenes are added to the liposomes as natural products contained in species, subspecies or varieties of the genus Olea that contain at least one of the triterpenes and/or biophenols in an amount greater than 0.001% of the dry vegetable matter, or the triterpenes and/or biophenols are extracted from the fruit-mill waste of species, subspecies or varieties of the genus Olea that contain at least one of the triterpenes and/or biophenols in an amount greater than 0.001% of the dry waste.
[0023] In addition, we recommend, although it does not limit the invention, that the triterpenes and/or biophenols used are in the form of concentrate or extract of species, subspecies or varieties of the genus Olea , and in solid or liquid form, and that at least one of the selected triterpenes and/or biophenols is present in the amount of between 10% and 95% of the total mixture of triterpenes and/or biophenols respectively.
Embodiment
[0024] One of the methods for preparing a cream with the previously described characteristics is comprised of the following steps:
[0025] Take a mixture of maslinic acid and oleanolic acid and dissolve it in hot propylene glycol.
[0026] Add cetyl alcohol and white wax by stirring and continue to heat the mixture.
[0027] Meanwhile, prepare, also hot, a mixture comprised of distilled water, sodium lauryl sulphate, liposomes, hydroxytyrosol and tyrosol. Stirring vigorously while still hot, add the aqueous phase to the lipid phase, thereby obtaining a white cream suitable for use.
[0028] A more fluid cream can be obtained by slightly increasing the amount of distilled water used.
EXAMPLE ONE
[0029] By way of representative, but not limiting, example of the preparation of a cream, we will describe the addition of triterpenes and biophenols to the world-famous base Beeler, duly liposomed for the production of 102 grams of preparation:
[0030] Take 2 grams of the mixture that contains 85% of maslinic acid and 14% of oleanolic acid and dissolve it in 10 grams of hot propylene glycol; add 15 grams of cetyl alcohol and 1 gram of white wax by stirring and continue to heat the mixture.
[0031] Meanwhile, prepare, also hot, a mixture of distilled water (36 grams), sodium lauryl sulphate (2 grams), liposomes (36 grams) and 0.2 grams of biophenols (90% hydroxytyrosol and 7% tyrosol). Stirring vigorously while still hot, add the aqueous phase to the lipid phase, thereby obtaining a white cream suitable for use.
[0032] A more fluid cream can be obtained by slightly increasing the amount of distilled water used.
[0033] In order to prepare a liposomed cream only with biophenols, follow the method described but without including the corresponding triterpenes in the apolar phase.
EXAMPLE TWO
[0034] We can start with a prior propylene glycol base (10 grams) containing between 0.1 and 2 grams of triterpenes and between 0.1 and 2 grams of biophenols. To this base add, hot and by stirring, 15 grams of cetyl alcohol and 1 gram of white wax. Meanwhile, prepare, also hot, a mixture of distilled water (36 grams), sodium lauryl sulphate (2 grams), liposomes (36 grams). Stirring vigorously while still hot, add the aqueous phase to the lipid phase, thereby obtaining a white cream suitable for use.
EXAMPLE THREE
[0035] The formulation of the invention may have the following composition:
[0000]
mg/100 g
Maslinic Acid
0-20000
Oleanolic Acid
0-10000
Tyrosol
1-20000
Hydroxytyrosol
1-10000
Propylene glycol
0-50000
Liposomes
100-99000
Cetyl alcohol
0-50000
White wax
0-50000
Sodium lauryl sulphate
0-50000
Distilled water
q.s. 100 g
[0036] In a specific embodiment, the formulation has the following formulation:
[0000]
mg/100 g
Maslinic Acid
1.7
Oleanolic Acid
0.28
Tyrosol
0.18
Hydroxytyrosol
0.02
Propylene glycol
10
Liposomes
36
Cetyl alcohol
15
White wax
1
Sodium lauryl sulphate
2
Distilled water
q.s. 100 g | The present invention relates to compositions of natural biophenols and, optionally, of natural biophenols and triterpenes obtained from the genus Olea . The compositions comprise said biophenols and/or triterpenes included in liposomes. The preferred biophenols within the context of the invention are tyrosol and hydroxytyrosol and the preferred triterpenes are maslinic acid and oleanolic acid and/or their salts. | 0 |
FIELD OF THE INVENTION
The present invention relates to methods and apparatus for measuring parameters in well bores which traverse earth formations, and more particularly to methods and apparatus for obtaining permeability and producibility measurements of formation intervals therein.
BACKGROUND OF THE INVENTION
During the drilling of a well, such as an oil well, progress is monitored by means of periodic measurements and tests. Some are made at the surface; others utilize sophisticated tools which are lowered into the well to make more proximate measurements of well bore parameters. Inferences and deductive evaluations about the well are then made based upon the results of such measurements, made at various depths within the well bore. Obviously, the greater the accuracy of the measurements, the more valid will be the deductions or calculations made from the measurements.
A well-known and important tool for measuring formation pressures and flow rates, and for obtaining one or more fluid samples from the earth formations, is a Formation Tester. When adapted to obtain a number of measurements or fluid samples, it is sometime called a multiple sample formation tester. One such tester, capable of making multiple measurements and taking multiple samples, is disclosed in U.S. Pat. No. 4,375,164 (Dodge et al., issued Mar. 1, 1983), assigned to the assignee of the present invention. As illustrated therein, the tool is adapted to be lowered into a well bore on an armored electrical cable, commonly known as a wire line. At the location in the well bore where a test is desired, a back-up shoe and an elastomeric sealing pad are projected laterally in opposite directions into engagement with opposite sides of the wall of the well bore. The sealing pad seals off a portion of the formation from the well bore, and a channel within the pad, oftentimes including a probe which extends therefrom into the formation, provides direct fluid communication between the tool and the formation interval thereadjacent. The flow channel then effectively opens the formation interval into the tool, where a pressure sensor provides a formation pressure measurement. If desired, a sampling chamber within the tool may also be connected to the formation, as by suitable valves, for obtaining and retaining therein a fluid sample which may then be retrieved at the surface when the tool is withdrawn from the well bore.
Another feature of such tools is the ability to perform pretests before a full fluid sample is drawn. The latter usually amounts to from 0.5 to 10 gallons, and usually can be drawn only once or twice (depending upon the tool configuration) for each trip of the tool into the well. A pretest, however, typically involves drawing only a small fluid sample, usually about 5 to 20 cc. Such samples can be drawn with a piston arrangement in which the fluid can then be purged and the piston used again to draw another sample. Initially, such tests help determine whether a good seal between the pad and the formation has been established. After the integrity of the seal is confirmed, more such pretests can be conducted to provide useful information about the permeability of the formation, as by monitoring the fluid flow rate as a function of the pressure differential generated as the piston draws in the sample.
Such prior art tools and methods, however, conducted as described above, have in fact been conducting pretest measurements, not of the permeability of the formation to its own connate fluids, but of the permeability of the formation to mud filtrate from the bore hole. These can be substantially different values. For example, suppose that the connate formation fluid is a gas. Clearly the gas, which is an inviscid fluid which is compressible, will have markedly different viscosity and flow characteristics from the drilling fluid, which is a somewhat viscous liquid which is incompressible. In such a case the permeability values obtained from a pretest which draws mud filtrate (well bore fluid) can be expected to be very distorted from the actual permeability of the undisturbed formation. This distortion effect can be further enhanced by formation damage in the immediate vicinity of the borehole (where the measurements in fact take place) caused by the well bore drilling fluids and well bore fluid pressures. (This latter change in apparent permeability is known as the "skin effect".)
A need therefore remains for an improved method and apparatus for determining more accurately the flow properties of a formation interval traversed by a bore hole. Preferably, such a method and apparatus will provide permeability information about the formation based upon actual connate formation fluids, and will minimize skin effect and other distortions caused by the well bore fluids.
SUMMARY OF THE INVENTION
Briefly, the present invention meets the above needs and purposes with a method and apparatus which, after establishing direct fluid flow communication within a well bore with a formation interval, then draws a sufficiently large fluid sample from the formation interval to substantially remove the well bore invasion fluid from the immediate area. Subsequent flow from the formation is therefore of connate fluid rather than well bore fluid. In the preferred embodiment, a plurality of flow tests is then made to determine the formation flow properties which obtain with the actual connate formation fluids. Preferably, the flow tests are essentially the same as the pretests discussed above, except that they occur after the well bore invasion fluids have been removed from the immediate area of the formation interval from which the fluid samples are being drawn. Also, the flow tests according to the present invention are essentially unlimited in number, and subject to control of either the flow rate or the differential flow pressure, to obtain additional information from which the formation properties may be more accurately determined.
It is therefore an object of the present invention to provide an improved method and apparatus for measuring the permeability of earth formations traversing a well bore; to provide such a method and apparatus which can also determine the deliverability of such a well bore against essentially any sandface back pressure, including a determination of the open flow potential of the well; in which direct fluid flow communication is established with the formation through the wall of the well bore, following which a sufficiently large fluid sample is drawn from the formation interval to substantially remove the well bore invasion fluid from the immediate area and to flow connate formation fluid instead, and then subsequently at least one flow test is made from the formation interval to determine the formation flow properties which obtain with the actual connate formation fluids; and to accomplish the above objects and purposes with a highly versatile, uncomplicated, economical and efficient method and apparatus readily suited for use in the widest possible range of bore hole drilling and measurement operations.
Other objects and advantages of the invention will be apparent from the following description, the accompanying drawings and appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a figurative schematic illustration showing a well tool embodying the present invention located within a well bore;
FIG. 2 is a schematic representation of portions of the fluid sampling system within the well tool according to the present invention;
FIG. 3 illustrates fragmentarily an alternate embodiment of the system illustrated in FIG. 2, adapted for more easily purging fluids within the pretest chamber to the well bore;
FIG. 4 shows schematically another embodiment of the FIG. 2 system provided with means for controlling the rate at which the pretest is taken;
FIGS. 5 and 6 illustrate additional embodiments for making pretests at controlled rates;
FIG. 7 illustrates still another embodiment for making pretests at controlled rates;
FIG. 8 represents the pressure levels in the tool hydraulic control lines during operation of the embodiment illustrated in FIG. 7; and
FIG. 9 is a graphical plot illustrating the determination, according to the present invention, of the deliverability of the well against any sandface back pressure.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
With reference to the drawings, the new and improved formation testing tool for measuring the permeability of earth formations traversing a well bore, and the method therefor according to the present invention, will now be described. FIG. 1 shows, somewhat figuratively, a formation testing tool 10 as it would appear in the course of a typical formation fluid sampling and permeability measuring operation in a well bore 11. Well bore 11 traverses earth formations, including permeable formations 12 and 13, and is typically filled with a well control liquid such as drilling mud. Tool 10, shown adjacent, formation 12, is sized for passage through the well bore 11, and is connected to the end of an armored electrical cable 14, which is spooled at the earth's surface in conventional fashion on a suitable winch or reel (not shown). In addition to physically supporting and moving tool 10 within the bore hole 11, cable 14 also provides an electrical link with surface equipment such as a control system 15, recorder 16, and power supply 17, for transmission through the cable of electrical control signals, electrical power for the tool, and data between the tool and the equipment at the earth's surface.
The tool body 18 encloses the measuring system (described further below). Intermediate the length of the tool are a selectively extendible sealing pad 19 and an anchoring shoe 20. Pad 19 and shoe 20 are at diametrically opposite locations on the tool body and are adapted to be extended from a retracted position, with respect to the body, to an extended position in engagement with the wall of the well bore 11 on opposite sides thereof. In the extended positions of the pad and shoe, pad 19 presses its elastomeric sealing element 21 into fluid tight engagement with the wall of the well bore 11 so that a fluid sample from the earth formation thereadjacent may be routed through element 21 to the interior of tool 10 for measurement and/or retrieval. Element 21, when properly positioned against the well bore wall, establishes a seal with the formation which isolates the adjacent formation interval from the fluids within the well and establishes, through the wall of the well bore, direct fluid communication with the adjacent formation.
Referring to FIG. 2, a simplified schematic representation of portions of the fluid sampling system according to the present invention is illustrated. A tool hydraulic system 25 is connected for extending and retracting pad 19, a fluid sampling probe 26 therein, and backing shoe 20 (FIG. 1). A reservoir 27 is shown for supplying fluid, as needed, to system 25 through an intake line 28, and receiving discharged hydraulic fluid, as through a line 29. For a more complete description of the operation of the tool's hydraulic system 25, reference may be had to the above-noted U.S. Pat. No. 4,375,164, the disclosure of which is incorporated herein by reference.
As indicated above, after the pad is set, prior art wireline formation testers typically perform either one or two pretests, with fixed and constant flow rates. The tests are to determine if there is a good seal between the pad 19 and the formation (i.e., if the formation is isolated from the well bore fluids), to determine the formation pressure, and then to estimate formation permeability from the pressure measured by the pretest sample piston as the small pretest volume (5-20 cc) is drawn. If the formation flows readily, a large sample volume (0.5-10 gal.) of formation fluid may then be drawn into one of the sample chambers 32 or 33 by opening a corresponding sample chamber valve 32a or 33a in fluid sample flow line 35. After the sample is taken, the valve 32a or 33a is closed, pad 19 is retracted from the well bore wall, and the tool 10 is then ready to move to another location.
As shown in FIG. 2, a pretest is performed by supplying hydraulic fluid from hydraulic system 25 through first and second pretest lines 37 and 38 to a pretest piston 40. Piston 40 has effectively three surface areas: A1 which communicates with the fluid sample flow line 35, A2 which acts hydraulically in the same direction as A1 but is much larger in area (for hydraulically multiplying the pressures to be applied on surface A1), and A3 which opposes A1 and is also much larger in area. (As illustrated, surfaces A1 and A2 are on the undersides of piston 40.) Pretest line 37 first supplies hydraulic fluid to piston side or area A2, causing the piston to move up. This produces a reduction in pressure in the formation fluid flow line 35, at piston area A1. When the pressure at A1 is less than the formation pressure, the formation fluid can then flow into the piston due to the pressure differential. The difference between the static formation pressure P and the pressure p in the fluid sample flow line 35 during movement of piston 40 is the differential flow pressure.
At the conclusion of the test valve 41 may be closed and valve 42 may be opened. This will disconnect piston 40 from the fluid sample flow line 35 and connect its sampling side A1 through valve 42 to the well bore for discharging the fluid sample by supplying hydraulic fluid through line 38 to piston surface A3. This is preferable to forcing the fluid back into the formation. Rather than using valves which must be affirmatively actuated, passive check valves 43 and 44 may be used, as illustrated in FIG. 3.
As will be apparent, the pretest actuating hydraulic fluid in the FIG. 2 embodiment flows at a fixed rate through line 37. According to one feature of the present invention, the flow rate may be controlled continuously to make one or more flow tests with piston 40 at a constant differential flow pressure. Further, when more than one test is made, each may be at a different constant differential flow pressure (or at different constant flow rates, if desired). This may be accomplished by changing the motor speed in hydraulic system 25, or by changing the pump output therein by using a variable displacement pump.
FIGS. 4-8 illustrate other means for controlling the flow rate of the hydraulic fluid supplied to side A2 of piston 40. In FIG. 4 an adjustable bypass valve 46 bleeds a controllable volume of the pump output back to the hydraulic reservoir 27. In FIG. 5, variable restrictions, such as throttle or needle valves 47a and 47b, may be placed in the actuating hydraulic line 37 or the exhaust hydraulic line 38. FIGS. 6 and 7 show a series of pistons 40a-40d, or pretest chambers. In FIG. 6 each piston has its own actuating solenoid valve 51a-51d and its own flow rate control valve or orifice 52a-52d which fixes the respective flow rate of the actuating hydraulic fluid to each pretest chamber, each orifice preferably having a different setting.
Finally, FIG. 7 shows sequence valves 53a-53d which open sequentially as the pressure rises in hydraulic line 37. This is, as fluid is first supplied to valves 53a-53d, the pressure rises until level 1 (see FIG. 8) is reached, at which pressure sequence valve 53a opens and lets hydraulic fluid flow to flow test chamber 40a. The output of hydraulic system 25 is preferably fixed by properly selecting the characteristic pump performance therein, so that the rate of movement of the flow test chambers is determined. Then, at the end of the stroke of chamber 40a, the pressure in line 37 rises until level 2 (FIG. 8) is reached. This causes valve 53b to open and lets hydraulic fluid flow to test chamber 40b, and so forth for valves 53c and 53d and chambers 40c and 40d. Further, by having different ratios of the areas A1 and A2 on each flow test chamber, multiple rate formation fluid flow tests can be provided with different fixed flow rates.
As taught by the present invention, is is particularly advantageous, and much information can be gained, by performing one or more of these tests after a large sample has been drawn into one of the sample chambers 32 or 33. Such tests will yield a much better estimate of formation permeability than a pretest performed before a large sample is taken, since the large sample removes substantially all of the well bore invasion fluid from the immediate area of the formation being tested, and flows connate formation fluid instead. This reduces the skin effect, which is the change in the flow characteristics around the well bore due to the invasion of drilling fluids into the formation. True connate formation fluids nearly always have a different viscosity than the well bore invasion fluid and thus flow differently. This is especially true, of course, of gas wells.
A standard practice during drill stem or production testing of gas wells is the four point flow test, in which the flow rate is changed three or four times and the flow rate and pressure histories are recorded. A graph of Δp 2 =(P 2 -p 2 ) vs. q on logarithmic coordinates is constructed (see FIG. 9), where
P=the average reservoir pressure obtained by shut-in of the well to complete stabilization,
p=the flowing sandface pressure during a given test,
q=the measured flow rate,
C=a coefficient which describes the position of the stabilized deliverability line, and
n=the inverse slope of the back pressure line or deliverability relationship defined by the plot of points.
C and n are constants characteristic of the well.
From this data the equation q=C(P 2 -p 2 ) n can be solved for C and n, allowing one to determine the open flow potential of the well or the deliverability of the well against any sandface back pressure. More particularly, when the well is either drill stem tested or production tested, then any one test, at a given flow rate, will be sufficient to determine a point on the graph of (P 2 -p 2 ) vs. q, and thus allow one to solve for C. Then by utilizing several pretest results (taken after the large sample was drawn to purge the bore hole fluids from the formation) at different flow rates, the slope 1/n can be readily found.
As may be seen, therefore, the present invention has numerous advantages. First, it provides for comparing the change in formation permeabilities measured before and after the large sample is drawn to determine therefrom the extent of possible formation damage due to the prior invasion of drilling fluids from the well bore into the formation. It lends itself to an automatic control system which monitors the pressure in the formation fluid line 35 and automatically throttles to any desired differential pressure, allowing analysis of a formation using a spectrum of flow rates for many different differential pressure values. It provides a much more accurate determination of the formation flow properties by measuring with the actual connate formation fluids. It is easy and straightforward to implement, highly versatile, uncomplicated, economical and efficient, and readily suited for use in the widest possible range of bore hole drilling and measurement operations.
While the methods and forms of apparatus herein described constitute preferred embodiments of this invention, it is to be understood that the invention is not limited to these precise methods and forms of apparatus, and that changes may be made therein without departing from the scope of the invention. | A method and apparatus for measuring the permeability, as well as the deliverability, of earth formations traversing a well bore, includes drawing one or more formation flow tests, usually of small volume, from a given formation interval after the region of the formation immediately surrounding the test area is purged of well bore invasion fluid. The purging, done by first drawing a large fluid sample from the formation interval to remove well bore invasion fluid from the immediate area and displace it with connate formation fluid, provides thereby for determining the formation flow properties which obtain with the actual connate formation fluids, as well as for estimating formation damage due to prior invasion of well bore fluid. | 4 |
FIELD OF THE INVENTION
[0001] This disclosure relates in general to measuring stress, strain, and fatigue of tubular oil and gas well equipment, and particularly to conduits located within a wellhead housing.
BRIEF DESCRIPTION OF THE DRAWINGS
[0002] FIG. 1 is quarter-sectional view of a portion of a surface wellhead assembly of an offshore well, and shown having a measuring system in accordance with an exemplary embodiment.
[0003] FIG. 2 is a schematic side elevational view of a portion of the casing hanger of the wellhead assembly of FIG. 1 .
[0004] FIG. 3 is an enlarged view illustrating a measuring gage that is bonded to the casing hanger as illustrated in FIG. 2 .
[0005] FIG. 4 is a schematic sectional view illustrating inserting a reader under a pressure controlled environment for reading one of the gages of FIG. 2 .
DETAILED DESCRIPTION
[0006] In the drawings and description that follows, like parts are marked throughout the specification and drawings with the same reference numerals, respectively. The drawings are not necessarily to scale. Certain features of the invention may be shown exaggerated in scale or in somewhat schematic form and some details of conventional elements may not be shown in the interest of clarity and conciseness. The present invention is susceptible to embodiments of different forms. Specific embodiments are described in detail and are shown in the drawings, with the understanding that the present disclosure is to be considered an exemplification of the principles of the invention, and is not intended to limit the invention to that illustrated and described herein. It is to be fully recognized that the different teachings of the embodiments discussed below may be employed separately or in any suitable combination to produce desired results. The various characteristics mentioned above, as well as other features and characteristics described in more detail below, will be readily apparent to those skilled in the art upon reading the following detailed description of the embodiments, and by referring to the accompanying drawings.
[0007] Referring to FIG. 1 , a housing 11 is located at the upper end of a riser (not shown) that extends downward to a subsea wellhead assembly. Housing 11 is mounted stationarily on an offshore platform in this example, and the platform has legs that extend to the seafloor. The riser and housing 11 are stationary relative to the platform and not subject to wave and current movements.
[0008] Another component of the surface wellhead assembly includes a casing head 13 mounted on housing 11 by a connector 15 . Casing head 13 is a tubular member having a bore 17 extending through it. Casing head 13 has a plurality of load shoulders 19 , which in this example are retractable. Each load shoulder 19 is retracted by a screw assembly 21 in this embodiment. While in the extended position shown in FIG. 1 , load shoulders 19 protrude into bore 17 . Alternatively, load shoulders 19 could comprise a single fixed load shoulder.
[0009] A casing hanger 23 is supported on load shoulders 19 . Casing hanger 23 supports a string of casing 25 , which has a lower end that latches or ties back to a subsea casing hanger in the subsea wellhead housing at the seafloor. The operator wishes to apply tension to casing 25 to a desired level and to maintain casing 25 at that amount of tension. Applying and maintaining the tension may be handled in different ways. For example, a ratcheting mechanism may be employed. The ratcheting mechanism allows part of the casing hanger to ratchet upward relative to the casing head, but not downward so as to hold tension. In this embodiment, however, casing hanger 23 has an outer body 27 that secures to external threads 29 on casing hanger 23 . Casing hanger 23 also has a set of interior threads 31 or a profile for securing to a running tool (not shown). While one portion of the running tool pulls tension on casing hanger 23 to provide the desired amount of tension in casing 25 , another portion of the running tool rotates outer body 27 downward into contact with load shoulders 19 . In FIG. 1 , the upper end of outer body 27 is shown spaced below a downward facing shoulder 32 on the upper portion of casing hanger 23 . While being run-in, the upper end of outer body 27 will be in contact with downward facing shoulder 32 . A stop ring 33 located at the lower end of threads 29 provides a limit to how far downward outer body 27 can be rotated.
[0010] Also, in this embodiment, a mechanism may optionally be included to prevent any upward movement of casing hanger 23 relative to casing head 13 after installation. This mechanism includes a lock ring 35 that is a split ring that is expanded outward into a mating profile 36 by means of a tapered energizing ring 37 . After outer body 27 has been rotated downward into contact with load shoulders 19 , the running tool pushes energizing ring 37 downward to move lock ring 35 into profile 36 .
[0011] After casing 25 has been tensioned and outer body 27 set, the operator would typically remove the running tool, then install a seal 41 . Seal 41 is located on the upper end of a spacer 39 that contacts the upper end of energizing ring 37 . Seal 41 may be of various types, either metal-to-metal or elastomeric. Seal 41 seals between the outer diameter of the upper portion of casing hanger 23 and casing head bore 17 .
[0012] In this example, two additional casing strings 43 are shown extending through casing 25 . Each string 43 may be tensioned and supported similarly in casing heads located above casing head 13 . Also, a string of production tubing 45 is shown extending through inner casing string 43 . Tubing string 45 may also be tensioned and supported in a tubing head in the same manner.
[0013] While installing casing strings 25 , 43 and tubing 45 , it would be advantageous to be able to know the strain and the amount of tension that exists after the casing hangers or tubing hanger are set. Also, from time to time it would useful to monitor the strain to determine if the initial tension has decreased, such as might occur if the platform settles. Fatigue can occur due to cycles of stress, either from thermal changes or other factors. Although casing head 13 and the various housings for the casing strings 43 and tubing 45 are located on a platform above the sea, casing strings 25 , 43 and tubing 45 are concealed within the housings and other tubular members. Consequently, conventionally measuring strain in the same manner as one would to accessible conduits is not possible.
[0014] In this exemplary embodiment, a plurality of gages 47 are mounted on casing hanger 23 below threads 29 . Each gage 47 is of a type that will provide an indication of strain without requiring any wires or a battery. As shown schematically in FIG. 3 , each gage 47 is a thin film of a polymer that is coated with an adhesive for bonding to a metal conduit. Alternately, each gage 47 could be laser etched directly onto the steel body of casing hanger 23 . Each gage 47 has a plurality of apertures 46 that are laser-machined in a geometric pattern. Apertures 46 are spaced evenly apart from each other in a row and are preferably identically sized. In this example, apertures 46 extend axially along one side edge of gage 47 and horizontally along another side edge. When tension is applied, gage 47 stretches slightly, changing the spacing between apertures 46 . This change in spacing is detectable and provides an indication of the stress being applied and the strain occurring.
[0015] Optionally, each gage 47 may have one or two rows of apertures 48 that are spaced apart from each other different amounts and have different widths to define a bar code containing information. In this example, apertures 48 extend along the other axial side edge and other horizontal edge from apertures 46 . Optionally, a central aperture 50 may be cut in the film of gage 47 , but that is not necessary.
[0016] A reader 51 optically reads apertures 46 , 48 of gage 47 and provides direct measurement of strain and other information. Reader 51 has a lens, a ring light source and strain measurement software. Reader 51 is located within a view port 49 that extends through the sidewall of casing head 13 . Preferably, view port 49 is located on a radial line of the axis of casing head 13 . A flange 53 bolts to the exterior of casing head 13 around view port 47 . An electrical lead 57 extends through a seal assembly 55 of flange 53 and extends to a processor and display 59 that may be located on another level on the platform, such as at the rig floor. Processor 59 contains algorithms that will provide a readout of strain directly based on the optical reading of reader 51 . Gages 47 , reader 51 and processor 59 are commercially available. One manufacturer is Direct Manufacturing, Inc., Columbia, S.C.
[0017] Because the operator will not know in advance exactly how much stretch will exist in casing 25 once tensioned, preferably a plurality of gages 47 are mounted to casing hanger 23 and axially spaced apart from each other. FIG. 2 shows three rows of gages 47 and they are axially spaced so that with the least amount of stretch expected, the upper row will be visible to reader 51 . With the maximum amount of stretch in casing 25 expected, the lower row of gages 47 would be readable by reader 51 .
[0000] Also, typically while running casing 25 , the operator does not orient casing hanger 23 to any particular rotational position relative to casing head 13 . While orientation can be done, an alternative is to mount a number of gages 47 in horizontal rows extending completely around casing hanger 23 . At least one of the gages 47 will always be aligned with reader 51 , regardless of the orientation of casing hanger 23 . In addition, more than one view port 49 is preferably employed, with the view ports being spaced circumferentially around casing head 13 . The additional view ports 49 allows an operator to insert reader 51 and make readings from different sides of casing hanger 23 .
[0018] In the preferred embodiment, a reader 51 is positioned in casing head 13 while casing 25 is being tensioned. The operator will thus be able to read the strain directly from the display of processor 59 while the tensioning procedure is occurring. The operator will thus know the level of tension that exists in casing 25 after the running tool has been disconnected from casing hanger 23 and outer body 27 landed on load shoulders 19 . Afterward, the operator can remove reader 51 and use it for tensioning inner casing strings 43 and tubing 45 , each of which will contain gages 47 attached to their hangers in a similar manner.
[0019] Also, periodically the operator can insert reader 51 into one of the view ports 49 to monitor the strain in subsequent years. This information allows the operator to determine the tension and fatigue. If pressure control is needed, this can be readily handled by the use of a lubricator assembly 61 , schematically shown in FIG. 4 . The operator inserts reader 51 into view port 49 on an insertion tool 63 . Insertion tool 63 comprises a tubular rod through which lead 57 will extend. Lubricator assembly has a valve 65 , on its inner end and an injection head 67 on its outer end. The operator closes valve 65 and inserts reader 51 into a chamber located between valve 65 and injection 67 . Injection head 67 is a conventional sealing mechanism that typically employs a pump that pumps grease around a tubular member to form a seal and simultaneously allow the tubular member to be moved along its axis. In this application, injection head 67 is actuated to maintain a seal around insertion tool 63 while valve 65 is opened and insertion tool 63 pushed inward to push reader 51 into close proximity to one of the gages 47 . After taking a reading, the operator reverses the procedure to remove reader 51 .
[0020] It is understood that variations may be made in the above without departing from the scope of the invention. While specific embodiments have been shown and described, modifications can be made by one skilled in the art without departing from the spirit or teaching of this invention. The embodiments as described are exemplary only and are not limiting. Many variations and modifications are possible and are within the scope of the invention. Accordingly, the scope of protection is not limited to the embodiments described, but is only limited by the claims that follow, the scope of which shall include all equivalents of the subject matter of the claims. | A system for monitoring strain in a wellbore casing includes one or more gages that are affixed to an outer surface of the wellbore casing. Each gage includes one or more apertures. During operation, variations in the shape and spacing of the apertures are monitored and used to determine a level of strain in the wellbore casing. | 4 |
This invention relates to a pollution prevention system. More particularly, it relates to a pollution prevention system which avoids the discharge, inadvertent or otherwise, of laboratory waste, and, particularly hazardous laboratory waste, into a public sewage system and subsequently into the natural environment.
BACKGROUND OF THE INVENTION
A wide variety of waste delivery systems are known in the art. Some of such systems may include steps to remove and/or isolate pollutants, such as hazardous laboratory waste, from waste materials to be delivered to a public sewage system and then into the natural environment, or steps for the treatment of such pollutants within the system to neutralize the same before delivery into a public sewage system and then into the natural environment. Thus, many of the known systems involve relatively sophisticated and complex operational steps and, as well, sophisticated and complex apparatus for accomplishing the same. Moreover, in recent years, the necessity of cleaning up the natural environment has resulted in the enactment of environmental legislation on the part of State and Federal Governments to enhance the quality of the environment by reducing and/or eliminating adverse environmental activities and has resulted in the exertion of pressures on industrial operators in order to not only protect the natural environment but also to protect the public against the adverse effects of industrial pollution and, thus, increase the quality of life for the public in general.
The enactment of environmentally protective laws, including the enforcement of the same by the imposition of severe penalties, has brought about the development of a substantial body of environment enhancing and protecting technology. Some typical examples of recent, relatively simple devices of such technology include U.S. Pat. No. 5,438,713 of Aug. 8, 1995, which discloses a prefabricated bathroom module for installation onto a deck of a marine vessel; U.S. Pat. No. 5,413,705 of May 5, 1995, for a filterless drain separator which discloses structure, such as a centripetal separator, which allows separation of liquid and solids or particulate matter and permits the liquid to pass through and out of the drain while retaining the solids or particulate matter for removal and disposal; U.S. Pat. No. 5,388,288 of Feb. 14, 1995, which discloses a plumbing fitting which serves both as a test closure and a trap bushing for a T-fitting; U.S. Pat. No. 5,333,327 of Aug. 2, 1994, dealing with an apparatus for opening and closing a drain and showing a mechanism for remotely opening and closing a drain of a basin with a flexible rod moving through a non-linear tube; U.S. Pat. No. 5,325,549 of Jul. 5, 1994, which discloses a trap fitting assembly for mounting in flammable floors which prevents the spread of smoke and fire through a floor and ceiling; U.S. Pat. No. 5,267,361 of Dec. 7, 1993, which discloses a drain trap having an L-shaped inlet tube, a cap, a vertical discharge tube and a garbage blocking member; U.S. Pat. No. 5,255,402 of Oct. 26, 1993, which discloses a trap for a sink, or the like, having an easily removable bottom portion which permits the trap to be cleaned and lost articles removed; U.S. Pat. No. 5,249,398 of Oct. 5, 1993, which discloses a cesspool for handling waste water and which is provided with a drainage system having two separate odor locks which prevent the escape of odorless gas from the system through the cesspool; U.S. Pat. No. 5,236,137 of Aug. 17, 1993, which discloses an apparatus and method for garbage disposal cleaning; and U.S. Pat. No. 5,203,369 of Apr. 20, 1993, which discloses a sink trap having a generally semi-global main chamber, a shallow water chamber, a plurality of baffles for supporting the water chamber in the main chamber in an inwardly spaced relation and defining a plurality of volute passageways between the main and water chambers, and a cap detachably secured to the upper edge of the main chamber and an inlet pipe extending axially downwardly through the cap into the water chamber to lead drainage into the water chamber and discharging the drainage by overflowing the water chamber to flow through the volute passageways forming a turbulent liquid flow along a drainage pipe line to prevent the drainage pipe line from becoming choked with impassable matter.
While the above-mentioned Patents are exemplative of a variety of technological developments in some of the simpler and more fundamental areas of developments of environmentally beneficial systems, methods and apparatus and appear to provide answers to the various problems they were developed to overcome, they simply do not recognize the problem of the disposition of waste from research laboratory operations. This is especially so when the disposition, whether it be inadvertent or otherwise, of such laboratory wastes is encountered when cleaning laboratory equipment for further use during normal laboratory research operations.
In many chemical research laboratories in use today, a wide variety of hazardous materials are employed as initial reactants, or such hazardous material are generated as a result of experimental processes undertaken in connection with research activities. Moreover, many such materials may not only be hazardous to the environment and to humans from a health viewpoint, but even highly toxic to the extent that they cause death in humans, animals and plant life. Furthermore, while established operating standards of safety result in the disposition of most of such materials, the possibility of the existence of residues thereof in the laboratory equipment employed therewith during research activities must be taken into consideration when cleaning such equipment in the laboratory sinks, since introduction of such materials into the public sewage system, inadvertently or otherwise, may easily occur with consequent contamination of the public sewage system and the exterior environment. There exists, therefore, a need for providing a system and an apparatus which overcomes this problem. The present invention fulfills this need.
BRIEF STATEMENT OF THE INVENTION
In accordance with the invention, there is provided a pollution prevention system which avoids the discharge, inadvertently and otherwise, of laboratory waste, hazardous and benign, into a public sewage system and then into the exterior environment, the system, comprising in combination a laboratory sink provided with a drain and means for collecting waste material from the sink connected to the drain and provided with at least a pair of valved outlets, one outlet leading to the exterior of the means for collecting waste material and the other outlet connected to a public sewage system.
Still further, in accordance with the invention, there is provided apparatus for carrying out a pollution prevention system which avoids the discharge, inadvertent and otherwise, of laboratory waste, hazardous and benign, into a public sewage system and then into the exterior environment, the apparatus comprising in combination a laboratory sink provided with a drain and means for collecting waste material from the sink connected to the drain and provided with at least a pair of valved outlets, one outlet leading to the exterior of the means for collecting waste material and the other outlet connected to a public sewage system.
THE DRAWINGS
In order to understand the present invention more fully, reference is directed to the attached Drawings which are to be taken in conjunction with the following description of the inventive system and apparatus for accomplishing the same, and wherein:
FIG. 1 is a diagrammatic view in elevation, and partially in section, of apparatus for carrying out the pollution prevention system of the invention, and
FIG. 2 is a view in elevation, and partially in section, of a laboratory work bench arrangement for achieving the system of the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to FIG. 1, a pollution prevention system according to the invention comprises in combination a laboratory sink 10 provided with a drain 12 connected to a means 14 for collecting waste material from the sink.
The sink 10 may be made of a wide variety of suitable materials which are substantially inert, strong and resistant to destruction by contact therewith of destructive materials over long periods of time, such as strong acidic, basic and radio-active chemicals and the like. For example, the sink may be made from substantially inert heavy stoneware which has been appropriately shaped, or such stoneware which has been provided with a protective surface, such as by grinding and polishing to provide a hard, smooth surface and/or by providing a hard, smooth surface thereto by a glass or inert plastic coating, or the like, such as, for example, of polyethylene, polypropylene, polyhexamethylene adipamide, polyvinylchloride, or polycarbonate and the like. The drain 12 , as well as the means for collecting waste material 14 , may also be made of glass or of such plastic materials.
Still further, if desirable, the sink, waste collection means and drain may be made of metal, such as steel and the like, or other metallic materials which are resistant to the activity of destructive materials and/or which may be coated with the materials mentioned above.
The collection means for the waste material 14 is also provided with at least one pair of valved outlets 16 and 18 . Valved outlet 16 opens directly to the exterior atmosphere of the collection means for the waste material to allow withdrawal of samples of the waste material for testing to determine the presence of undesirable waste materials therein. On the other hand, valved outlet 18 is connected to a public sewage system 20 and will normally remain in a closed position until testing is completed and then opened to permit any waste material collected in the collection means 14 for delivery to the public sewage system and then to the exterior environment.
In addition, the pollution prevention system of this invention includes also a source of wash water, preferably by way of a faucet 22 , located in the vicinity of the sink to deliver water thereto and which in turn is connected to an appropriate plumbing system (not shown). It is to be understood, however, that is within the purview of this invention that wash water can be supplied by any convenient arrangement, such as, for example, by way of a hose arrangement, or even by a pail whose contents simply may be emptied into the sink.
While the above brief detailed description of the pollution prevention system of this invention as described sets forth the fundamental operative elements thereof, as a practical matter, the inventive system also is preferably provided with a level sensor 24 located on the exterior surface of the collection means 14 and near the top thereof. The level sensor 24 is connected to an appropriate electrical circuit 26 , which in turn, is connected to an alarm 28 . Alarm 28 is also preferably connected to faucet 22 in a convenient manner to shut off the flow of washing water when the level of waste material in the collection means has activated the sensor.
Still further, the pollution prevention system, according to the invention, includes the utilization of a drip pan or catch basin 30 which is disposed under the waste collection means 14 and which serves the purpose of collecting any spillage which may occur when taking test samples through valved outlet 16 . Drip pan 30 may be made from the same materials as waste collection means 14 .
Waste collection means 14 is preferably in the form of a container and may be round, rectangular, or any other desirable and convenient shape. Moreover, while it is preferably provided with an integral top 32 , such as shown in FIG. 1, and with an upwardly extending portion 34 , the upwardly extending portion is adapted to be connected to the drain 12 by a substantially liquid and air tight collar 36 to prevent leakage of any waste material passing down the drain and into the interior of the container. The collar 36 may be screw threaded or friction fitted to the drain 12 and to the waste collection means, as desired, and collar 36 may be made of the same materials, metallic or plastic, as mentioned above.
Referring now more particularly to FIG. 2, the pollution prevention system of the invention is shown there as incorporated into a working laboratory cabinet or bench arrangement in which the bench or cabinet, generally referred to by numeral 38 , is provided with a rear panel 39 , side panels 40 and 42 and a front panel 44 resting on a supporting member 46 which in turn is in contact with the laboratory floor 48 . Supporting member 46 also includes inwardly extending supports (not visible) to ensure a solid foundation for the system.
The cabinet panels, including rear panel 39 , support a counter top 50 provided with a pair of openings to support a pair of laboratory sinks 10 and 10 ′. The sinks are provided with drains 12 and 12 ′ connected to an additional T-shaped drain member 52 . In turn, the T-shaped drain member extends downwardly towards the waste collection means 14 which, in the version illustrated, is a circularly shaped carboy of polypropylene which is provided with an intregally formed cover member 54 having a central opening 56 through which there extends an integrally formed drain pipe 58 which is connected at its upper extremity to the T-shaped drain member 52 by a collar 36 which is preferably a Triclover sanitary connector. As with the system shown in FIG. 1, in the system of FIG. 2, the waste collection means 14 , that is the polypropylene carboy, is provided with a pair of valved outlets, one, 16 , which in this modification of the system is preferably a needle style sample valve 60 and the other, 18 , is a spring type poppet type outlet valve 62 . Both of these valves are connected to the carboy through nozzles or lines 64 and 66 , respectively. Just downstream from the outlet valve 18 , a collar 68 , which is preferably a Triclover sanitary connector, couples the outlet valve to a public sewage system 20 and from which a vent hose 70 , provided with appropriate barbed nipples 72 and 74 connect the hose to the public sewage systems and to the waste collection means 14 , respectively.
The modification of the pollution prevention system shown in FIG. 2 also includes a mixed water spout or faucet 22 provided with a “goose-neck” with vacuum breaker. The water spout on faucet 22 is connected through tubing 76 which extends downwardly towards the supporting member of the cabinet 38 . A normally closed solenoid valve 78 is located in the lower portion of the tubing 76 and connected to a spring closed foot pedal 80 which, in turn, is connected through a hot and cold water mixing valve 82 to hot and cold water sources 84 and 86 .
The solenoid valve 78 is provided with an activator 88 which is connected to a vacuum source 90 of preferably 120 pounds located in the interior of cabinet 38 behind the front panel 44 .
In the modification of the inventive pollution prevention system shown in FIG. 2, the waste collection means 14 , that is, the carboy, has, as does the system illustrated in FIG. 1, a level sensor 24 located on the exterior surface of the carboy. The sensor 24 is preferably a non-contact sensor and it is connected through appropriate circuitry 26 to a level alarm controller 92 located just behind the front wall of cabinet 38 . The controller 92 is in turn connected to an alarm light 94 and to a horn 96 , preferably a piezoelectric horn, both of which elements are located in the front panel of the cabinet 38 .
It is to be understood that it is within the purview of this invention to employ a wide variety of readily available elements in constructing a system according to the invention. For example, any of a wide variety of non-contact level sensors which are available in the market place may be utilized so long as they can appropriately be attached to and later removed from the waste collection means, so that the waste collection is means may be removed from the system and appropriately stored and/or disposed of, as desirable. Still further, any of a wide variety of readily available valve elements can also be employed in place of the needle style sample valve 60 , as well as in place of the spring type poppet outlet valve. Moreover, any of a wide variety of collars and sanitary connectors readily available in the market place may also be employed in place of the described collars and triclover sanitary connectors, so long as they are capable of functioning without leakage and thus obviate possible pollution problems which would occur by such leakage.
In addition, it is within the purview of this invention to employ any of a wide variety of signaling and alarm devices which are readily available in the market place, that is, either sound emitting horns or various colored lights which may be noticeable by their intensity or intermittent flashing.
Referring now once again to FIG. 1, a pollution prevention system according to the invention generally operates as follows.
Laboratory flasks and the like which have been employed in carrying out experiments and the like and which now must be cleaned for re-use and which may contain pollutants which must be washed away are introduced into the sink 10 and washed and rinsed to remove any such pollutants therefrom. At this stage, valves 16 and 18 are in their closed positions. Thus, any wash and rinsing water passes through the drain 12 and into the waste collection means 14 . Should it be desired at any time during with washing and rinsing stage to check for the presence of pollutants in the wash and rinsing water delivered to the waste collection means, valve 16 is simply opened to drain off a portion of the contents which is then appropriately tested for the presence of pollutants by appropriate testing procedures. If no pollutants are detected, valve 18 can then be opened and the contents of the waste collection means can be drained into the public sewage system 20 and subsequently into the general outside environment.
On the other hand, if pollutants are detected, washing and rinsing is continued until the sensor means 24 , due to the level of material in the waste collection means, is activated and thus initiates, by way of the electrical circuit 26 , a signal by the piezoelectric horn 94 and/or the light 96 and which, at the same time, shuts off the flow of wash water through the faucet 27 . When the last event has occurred, the waste collection means 14 , such as a carboy, for example, is removed simply by opening collar 36 to separate the waste collection means from the drain 12 . The waste collection means can then be removed and closed by disposition of an appropriate air tight and liquid tight cap on the upwardly extending portion 34 thereof. After such sealing, the waste collection means is then simply removed for storage and/or disposition. This procedure is then repeated, as needed.
The present invention presents many advantages. For example, it provides a system which is easily operated, and which, at the same time, employs a wide variety of elements which are readily available in the market place and which can be assembled and utilized in a relatively simple manner. Moreover, the various elements employed and which must be disposed of after utilization of the system, are relatively inexpensive and those parts of the system which are reusable can be salvaged for such further reuse, thus obviating the need to replace them after each use.
Consequently, that portion of the system, once initial costs have been undertaken and due to the fact that such elements can be reused, holds down future costs of operation of the system.
Numerous other advantages of the invention will be readily apparent to those skilled in the art.
Accordingly, this invention is not to be limited to the embodiments disclosed and illustrated herein, except as defined in the appended claims. | There is disclosed a waste prevention system which avoids the discharge, inadvertent or otherwise, of laboratory waste, into a public sewage system and subsequently into the natural environment. The system employs, in combination, a laboratory sink having cooperatively connect thereto a carboy for collecting pollutants. The carboy is provided with elements to permit removal of samples of materials delivered thereto from the sink for testing of the same to determine the presence of pollutants. In the event no pollutants are present, the carboy may simply be opened and any wash or rinse water from the sink can be delivered into a public sewage system and then to the environment. In the event testing indicates the presence of pollutants, the carboy then can be filled to the required level, which is indicated by a sensing device connected electrically to signaling devices, such as a horn and/or light and which is also connected to the source of washing water and automatically will stop the flow of such washing water into the sink. The carboy can then be removed from the system and stored and/or disposed of, as desired. | 4 |
RELATED APPLICATIONS
[0001] This application is related to U.S. patent application Ser. No. 12/554,795 filed on Sep. 4, 2009 now U.S. Pat. No. 9,192,376.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH AND DEVELOPMENT
[0002] N/A
BACKGROUND OF INVENTION
[0003] 1. Field of the Invention
[0004] The present invention relates generally to a surgical suturing device, more specifically, to an ergonomic rotational action needle driver which enhance the tissue suturing procedure, particularly the one performed on restricted, deep and less accessible locations.
[0005] 2. Background of the Invention
[0006] Surgical procedures have proliferated among the medical practice as new treatments are developed to effectively treat common and extraordinary conditions. The spectrum of invasiveness goes from simple tissue suturing of small open wounds to complicated procedures as those performed in vascular or neurological surgeries. It is undoubted that each and every step on any surgical procedure is of great importance and could cause negative consequences for the patient if it is inadequately performed. The suturing procedure, in particular, could end in serious consequences for the patient if negligently conducted, causing damages to adjacent tissues or even organs.
[0007] It is known that the suturing procedure consumes a considerable amount of time of the surgical treatment. Simplification of the suturing procedure by developing more effective suturing devices will reduce the time spent on that task and at the same time will reduce the risk of negative consequences arising from damages caused to adjacent tissues or organs.
[0008] Generally, the instruments used in suturing procedures are the suturing material, the suturing needle and the suturing driver. Efforts made to reduce the suturing time and to enhance the suturing procedures' safety have been focused on performing needle driver's modifications. One of the generally unattended deficiencies of the available needle drivers is the handedness of its designs. Some of the deficiencies were attended by U.S. patent application Ser. No. 12/554,795 filed on Sep. 4, 2009 now U.S. Pat. No. 9,192,376. The entire content of U.S. Pat. No. 9,192,376 are hereby incorporated by reference.
[0009] However there is a need to provide a less cumbersome mechanism for a rotational driver rotational action needle driver. Therefore the present invention provides a more efficient simple mechanism as a rotational action needle driver.
SUMMARY OF THE INVENTION
[0010] The disclosed embodiment of the present invention helps provide an effective suturing device that enhances the maneuvering and safety of suturing procedures. The disclosed invention consists of a suturing needle driver that comprises an ergonomical handle that eases the suturing process. It also comprises a rotational mechanism that permits users to maintain the needle tightly fixed to the needle driver in order to have a best control over the needle and the movements related to the suturing process. It permits the user to position the suturing needle at the exact angle at which the suturing material has to be inserted into the tissue.
[0011] Therefore, it can be appreciated that there exist a prevalent necessity for new and improved ergonomical suturing device to perform safest and simplest suturing procedures. The present disclosure overcomes the inability of the prior art to foresee the need of an less cumbersome suturing needle driver that permits users to performed safe suturing procedures.
[0012] Another deficiency presented by the prior art is the lack of disclosure of needle driver having a rotational mechanism that permits to fix the needle to a specific angle before inserting it into the tissue and combining the said rotation with ergonomic characteristics in order to facilitate the suturing processes.
[0013] In light of the foregoing, it will be appreciated that what is needed in the art is a suturing needle driver lacking of handedness and combining a rotational mechanism. Thus, the object of the present invention is to provide a surgical device that eases the suturing procedure associated with deep, restricted areas.
[0014] Another object of the present invention is to provide a surgical suturing needle driver that permits to grasp, secure and rotate a curved surgical needle without requiring a rotational motion at the surgeon's wrist.
[0015] It is the object of the present invention to provide a surgical suturing needle driver which incorporates a rotational mechanism that secures the needle to the needle driver and permits to diminish the number of maneuvers actually needed for performing the surgical suturing process, reducing the risk of damaging peripheral tissues.
[0016] It is a further object of the present invention to provide an ergonomically designed suturing needle driver that eliminates the difficulties associated with needle driver maneuvering that arise from the handedness of that kind of instrument.
[0017] The system of the disclosure itself, both as to its configuration and its mode of operation will be best understood, and additional objects and advantages thereof will become apparent, by the following detailed description of a preferred embodiment taken in conjunction with the accompanying drawing.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] FIG. 1 shows a perspective view of the exemplary embodiment in accordance according with the principles of the present disclosure.
[0019] FIGS. 2A and 2B shows perspective views of the exemplary embodiment with actuator at a first position in accordance according with the principles of the present disclosure.
[0020] FIGS. 3A and 3B shows perspective views of the exemplary embodiment with actuator at second position in accordance according with the principles of the present disclosure.
[0021] FIGS. 4A and 4B shows side views of the exemplary embodiment in accordance according with the principles of the present disclosure.
[0022] FIG. 5 shows a perspective view of the exemplary embodiment in accordance according with the principles of the present disclosure.
[0023] FIG. 6 shows a front view of the exemplary embodiment with actuator at second position in accordance according with the principles of the present disclosure.
[0024] FIG. 7 shows a front view of the exemplary embodiment with actuator at a first position in accordance according with the principles of the present disclosure.
[0025] FIG. 8 shows a top view of the exemplary embodiment with actuator at a first position in accordance according with the principles of the present disclosure.
[0026] FIG. 9 shows a bottom view of the exemplary embodiment with actuator at a first position in accordance according with the principles of the present disclosure.
[0027] FIG. 10 shows an exploded view of the exemplary embodiment in accordance according with the principles of the present disclosure.
[0028] FIGS. 11A and 11B shows a detailed view of the exemplary embodiment of locking mechanism in accordance according with the principles of the present disclosure.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0029] Turning to the diagram, FIG. 1 shows the device 1 of the present disclosure comprises a first elongated element 2 , a second elongated element 3 , an actuator 4 and rotational transfer element 6 and at least an elastic member 7 .
[0030] The first elongated element 3 , as shown in FIG. 2A-3B , includes a first elongated body 33 , a first tip 61 at a distal end and a round contour including a first socket 30 at the proximal end. The second elongated element 2 , as shown in FIG. 2B , includes a second elongated body 23 , a second tip 62 at a distal end and a round contour including a second socket 20 at the proximal end. The rounded contour of the first elongated element 3 and second elongated element 2 are ergonomically designed to rest against surgeon's palm his hand, permitting its proper use to right and left handed surgeons, therefore a resting palm wall 21 is provided coupled to the first socket 20 at the proximal end. The surgeon will maintain the handle fixed to the palm his hand by using his thumb.
[0031] The present device comprises several features presented from FIG. 1 through FIG. 11B . For example, an object of the present disclosure is to perform safest and simplest suturing procedures. The present suturing device 1 comprises a suturing mechanism including an actuator 4 , wherein said actuator 4 initiates the rotational mechanism during the suturing procedure using the present device 1 .
[0032] In accordance with the principles of the current disclosure the actuator 4 is mechanically coupled to the first elongated element 3 at a first pivot point, as shown in 2 A through 3 B. The actuator 4 is mechanically coupled to the first elongated body 33 by a pin 8 , wherein said pin 8 permits rotational movement or displacement of said actuator 4 with respects to said first pivot point. The actuator 4 comprises a platform 4 A, mainly extended away from the first elongated body 33 , configured or shaped to receive a thumb and be driven by said thumb, Base on the present exemplary embodiment the actuator is driven by the thumb, wherein said thumb pushes said platform 4 A towards the first elongated body 33 moving the actuator from a first position, as shown in FIGS. 2A-2B , to a second position, as shown in FIGS. 3A-3B . It is important to understand that the movement of the actuator 4 is a radial displacement wherein the center said radial displacement is provided by the first pivot point or pin 8 .
[0033] Further the actuator 4 comprises a linear actuator mechanism fixed to said platform 4 A, wherein said linear actuator comprises a rack 51 , which moves mainly vertical toward the first elongated body 33 . The rack 51 is configured or designed to interact with the rotational bar 6 , more particularly with the pinion 600 at a distal end of said rotational bar 6 , as shown in FIG. 2A through 3B . The interaction of the rack and pinion converts the radial displacement of the actuator 4 into a rotational movement of the rotational bar 6 . The rotational bar 6 structures is explained in more details below.
[0034] Another object of the present disclosure is to provide different direction of the rotation of said rotational bar 6 while using the actuator 4 . FIG. 4A is directed to show the displacement of the actuator with respects to the pin 8 . As shown the pin 8 comprises a length longer than the actuator length X 2 with respect to the pin 8 . For example the pin comprises a total length X 3 , and the actuator comprises an attachment portion 71 connected to the pin 8 comprising a second length X 2 . The difference between the lengths provides a space X 1 for the displacement of the attachment portion 71 . The displacement of said attachment portion 71 is enough to move the rack 51 from providing a rotational direction of the pinion to another direction (i.e. from counterclockwise to clockwise). For example, the space X′ 1 provided on FIG. 2A is positioned at a portion of the pin 8 different from the one showed in FIG. 4A . In fact the position of the rack 51 in FIG. 2A will provide clockwise motion of the pinion 600 and counterclockwise motion of the pinion 600 in FIG. 4A . It is important to understand that the movement of the actuator 4 , more particularly the displacement of the attachment portion 71 is accomplish when the actuator is in the first position.
[0035] The actuator 4 further comprises an elastic or resilient member 7 coupled to the platform 4 a . The elastic member 7 is configured to be compress from the first position to the second position. Subsequently as soon the platform 4 a is release returns to its original position or first position. The elastic member 7 in the exemplary embodiment is a spring configured to recoil the platform to the first position. It is important to understand that any other resilient member can be used as long assists to recoil the platform 4 a.
[0036] Further the first elongated body 33 extends from said first socket 30 towards said first tip 61 . The first elongated body 33 comprises at least a set of walls 331 , 332 forming a clearance between each other, as shown in FIG. 4A . The clearance between the walls is enough to provide space for the rotational bar 6 and a portion of the second elongated body 23 to be located between them while the suturing device 1 is in use. In the instant case the suturing device is considered in use when the tips 61 , 62 are grasping the needle N or in close contact.
[0037] In addition the second elongated element 2 , as mentioned, includes a second elongated body 23 , a second tip 62 at a distal end and a round contour including a second socket 20 at the proximal end. Further the elongated body 23 comprises a rotational bar support S. The rotational bar support S hold the rotational bar 6 in position with respect to the second elongated body 23 while provide bearing for the rotational movement of said rotational bar 6 when the actuator 4 interacts with the pinion 600 . The rotational bar is mechanical coupled to the second tip 62 , Therefore the rotational movement generated at the pinion is transferred to the second tip 62 .
[0038] The first elongated element 2 and the second elongated member 3 are joint together at the box joint P. The box joint P serves as an intersection or pivot point between the first elongated element 3 and the second elongated element 2 . As shown in FIG. 5 through FIG. 7 , the second tip 62 and first tip 61 extends away from the box joint P.
[0039] FIG. 5 through FIG. 9 shows the grasping portion created by first tip 61 and second tip 62 . In accordance with the exemplary embodiment the grasping force is preferred to be in an oblique manner, however the contact between tips 61 , 62 maybe provided in other angles. Each tip 61 , 62 is removable and comprises at least a distal end gear 60 . In accordance with the principles of the present disclosure the gear is intended to assists to transmit the rotational movement of the second tip 62 connected to the rotational bar 6 to the first tip during the suturing procedures. It is important to understand that the gear serves as a rotation transmitting element for assisting to transferring the rotational motion from second tip 62 to the first tip 61 , therefore any other rotation transmitting element could be used. Also each tip 62 , 62 comprises at least contact distal end 620 , 621 including grooves. The grooves or recess assists the increases the grasping force at the contact distal end 620 , 621 . The recess area may vary in order to assists to grasp different sizes of needles N. Further the tip 61 , 62 may vary in length. The tip 61 , 62 are made of any selected material capable to perform at least the functions herein mentioned. The selection of the material depends on the field the device is going to be employed. Also the contact distal end 620 , 621 is preferred to have a surface that assist the performed action. For example, while using the device in a suturing process is preferred to have a distal end or contact distal end surface cover with a material, such as but not limited to silicon or rubber, that provide some friction over the needle in order to keep a constant displacement of said needle. Further the tips may include a layer of antibiotic or any other medical substance that assist the suturing and healing process of the patient. As mentioned before, the tips are removable and securely installed at the distal end of said elongated elements 2 , 3 . It is important to understand that the tips 61 , 62 are removable and/or replaceable due to the need of grooves sizes for specific needles N or/and due to wear and tear problems, such as losing grasping force and/or avoiding particles losses due to friction.
[0040] A locking mechanism 200 is located between the first elongated body 33 and second elongated body 23 , as shown in FIGS. 11A and 11B . Each elongated body comprises a extended member with teeth interlocking with each other, in the form of a ratchet, assisting to hold the position between elongated bodies and consequently the distance between the first tips 62 and second tip 61 . Further from said extended member 200 , 201 comprise protrusion 22 a , 22 b . It is important to understand that the current device is usually on an open stage wherein the locking mechanism is not providing a constant distance between the first elongated element 3 and said second elongated element 2 . While using the device 1 the user desires to close the gap between the elongated elements 2 , 3 in order to provide a constant distance between these two parts, consequently the first tip 62 and second tip 61 are in close contact grasping the needle N.
[0041] Another advantage of the present suturing device 1 is the unlocking mechanism, shown in FIG. 11 a and FIG. 11 b . The actuator 4 , as previously disclosed, comprises a linear actuator including rack 51 and a flange 50 . The flange 50 comprises at least two bumps 50 a , 50 b . The bump 50 a , 50 b are intended to assists with the unlocking mechanism by pushing up protrusions 22 b , 22 a . The protrusion 22 b , 22 a extends from the locking mechanism 200 , 201 . The bumps 50 a , 50 b are preferably located closer to the platform 4 a . The purpose of providing the bumps 50 a , 50 b closer to the platform is to provide enough displacement of the rack 51 to rotate the pinion 600 before the bumps 50 a , 50 b interacts with the protrusions 22 a , 22 b . Therefore, when the actuator 4 is close to the second position the bumps 50 a , 50 b push up the protrusion 22 a , 22 b unlocking the rackets or locking mechanism 200 , 201 .
[0042] The disclosure is not limited to the precise configuration described above. While the disclosure has been described as having a preferred design, it is understood that many changes, modifications, variations and other uses and applications of the subject invention will, however, become apparent to those skilled in the art without materially departing from the novel teachings and advantages of this invention after considering this specification together with the accompanying drawings. Accordingly, all such changes, modifications, variations and other uses and applications which do not depart from the spirit and scope of the invention are deemed to be covered by this invention as defined in the following claims and their legal equivalents. In the claims, means-plus-function clauses, if any, are intended to cover the structures described herein as performing the recited function and not only structural equivalents but also equivalent structures.
[0043] All of the patents, patent applications, and publications recited herein, and in the Declaration attached hereto, if any, are hereby incorporated by reference as if set forth in their entirety herein. All, or substantially all, the components disclosed in such patents may be used in the embodiments of the present invention, as well as equivalents thereof. The details in the patents, patent applications, and publications incorporated by reference herein may be considered to be incorporable at applicant's option, into the claims during prosecution as further limitations in the claims to patentable distinguish any amended claims from any applied prior art. | A rotational action needle driver that comprises an cumbersome ergonomically designed handle, rotational mechanism and an integrated locking/unlocking system that permits surgeons to perform the surgical suturing procedure in a less complicated and more secure way by allowing more control over the suturing needle and the area to be stitched, even when the suturing area is small, deep, and/or restricted. | 0 |
BACKGROUND
1. Field of the Invention
The present invention generally relates to a method for fabricating a thin metal shell, and more particularly to a method for fabricating a thin metal shell having connecting components.
2. Description of the Prior Art
As the trends in household appliance, consumer electronics, computers and peripheral equipment move towards much lighter, thinner, shorter and smaller requirements, particularly the requirements for the portable products, are even stringent. Therefore, it strongly requires to use much lighter materials for the structural components (like frame, shield and partition plate) of the products in order to meet these requirements. Hence, in the early stage manufacturers of fabricating household appliance, consumer electronics, computers, and peripheral equipment utilize the plastic injection molding to fabricate the shell massively. They also dispose the mortise, tenon, slot, positioning pin/hole, reinforced rib, partition wall and sinking or bulge match components to rapidly connect, position and decrease the usage of the screws and action of screwing during the assembly process. However, plastic materials have the problems of low structural strength. These materials are easily fractured and scratched upon external impact and the decrease in size for the screw hole bases or the positioning pins is limited, otherwise they are easily fractured and broken. In addition, the plastic component has an electromagnetic interference (EMI) problem and thus the surface of the plastic component must do certain treatment to prevent EMI. This treatment will increase the cost of manufacturing.
Recently, applications of light metals have been tremendously increased to replace the plastic materials for manufacturing the shell components. These light materials used for manufacturing the shell components, such as magnesium (Mg) alloy, aluminum (Al) alloy and Titanium (Ti) alloy, have a high structural strength and can be made very thin. In addition, these alloys provide a better EMI protection and can be recycled. For example, U.S. Pat. No. 5,237,486 entitled “Structure Frame for Portable Computer” issued to LaPointe et. al. on Aug. 17, 1993 discloses a lightweight die-cast magnesium (Mg) alloy frame of the portable computer with the advantages of high structural strength, thinness, EMI protection. However, the technology of die casting or thixomolding for fabricating the thin shell components utilized in the U.S. Pat. No. 5,237,486 and in the current industry has a weakness of low yield rate. The yield rate is less than 60% and the thickness of A4 size shell cannot be less than 1 mm. Besides, the surface of the thin shell components by the die casting method usually has pores, voids or cracks. These imperfections need to be reworked by filling and multiple layer surface treatment so as to obtain delicate appearance. So, the cost will be very high.
Except the die casting method, manufacturers try to use the forging method to fabricate the thin metal shell components. This method has been successfully applied to thin metal shell components with small size, such as the shield of MD case (80×80 mm). However, there still exists technical difficulty for making large size thin metal shell components. In addition, no matter the thin metal shell components made by either the die casting or the forging method, the components need further mechanical machining (such as milling and tapping) to form connecting components thereon, which significantly increases the cost of manufacturing. Besides, flammable metals (like Mg alloy) are liable to burn during the processes of melting and refining, and mechanical machining. It will increase the danger during the manufacturing process.
In views of the disadvantages of low yield rate, limited size for thin metal shell components and danger during the manufacturing process according to the above-mentioned methods, there is a need to develop a new method for manufacturing the thin metal shell in order to overcome the above-mentioned disadvantages.
SUMMARY OF THE INVENTION
An object of the invention is to provide a method for fabricating the thin metal shell having connecting components, in which the present method can tremendously decrease the technical difficulty of fabricating the thin metal shell and make the subsequent surface treatment or coating processes become much easier, thereby decreasing the manufacturing cost.
Another object of the invention is to provide a method for fabricating the thin metal shell having connecting components, which utilizes the bonding technology to bond components tightly and does not need additional mechanical machining.
Another object of the invention is to provide a method for fabricating the thin metal shell having connecting components, in which the present method can get rid of the danger of using flammable alloys during the process of melting, refining, and mechanical machining, thereby improving the safety during manufacturing process.
Another object of the invention is to provide a method for fabricating the thin metal shell having connecting components, in which the connecting components such as outer screws or barbs, inner slots which are difficult to be formed by current manufacturing methods.
Another object of the invention is to provide a method for fabricating the thin metal shell having connecting components for producing much larger and thinner metal shell.
Another object of the invention is to provide a method for fabricating the thin metal shell having connecting components for improving the yield rate and quality stability of metal shell so as to decrease the manufacturing cost.
According to the present invention, a metal plate is firstly formed into a thin shell by plastic forming technology, and a plurality of connecting bases are also formed on the surface of the shell component; structure adhesives are applied to the connecting bases; connecting components are disposed on the connecting bases for positioning and connecting; finally, the structure adhesives which are used to bond the shell and connecting components are cured in order to bond those components. The technologies of plastic forming suitable for the present invention include, but not limited to, stamping, forging, drawing, extruding, progressive cold forming or superplastic forming process. The metals appropriate for this method include ferrous metals such as galvanized sheet iron and stainless steel plate; nonferrous metals such as copper (Cu) alloy, aluminum (Al) alloy, magnesium (Mg) alloy, titanium (Ti) alloy, zinc (Zn) alloy, nickel (Ni), tin (Sn), aluminum-lithium (Al—Li) alloy or superalloys composed thereof.
According to the present invention, the methods of bonding the connecting components to the thin metal shell include spot welding, laser welding, resistance welding or ultrasonic welding.
BRIEF DESCRIPTION OF DRAWINGS
Other objects, aspects and advantages will become apparent from the following description of embodiments with reference to the accompanying drawings in which:
FIG. 1 is a perspective view of a thin metal shell according to the first preferred embodiment of this invention.
FIG. 2 is a perspective view of a thin metal shell according to another preferred embodiment of this invention.
FIGS. 3 a - 3 b are perspective views of the reinforced thin metal shells according to the preferred embodiment of this invention.
FIGS. 4 a - 4 g are cross-section views of the thin metal shells with connecting components according to the preferred embodiment of this invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
This invention now will become apparent from the following preferred embodiments with reference to the accompanying drawings. In the accompanying drawings, the same reference numeral designates the same element. First, referring to FIGS. 1 and 2, the thin metal shell 10 is formed as a thin cover as shown in FIG. 1 or formed as a shell as shown in FIG. 2 by plastic forming technology. The thin metal shell 10 includes a main plate 13 and side plates 14 which surround the main plate 13 . The plastic forming techniques suitable for this invention include stamping, forging, drawing, extruding, progressive cold forming or superplastic forming process. The metals appropriate for this method include ferrous metals such as galvanized sheet iron and stainless steel plate; and nonferrous metals such as copper (Cu) alloy, aluminum (Al) alloy, magnesium (Mg) alloy, titanium (Ti) alloy, zinc (Zn) alloy, nickel (Ni), tin (Sn), aluminum-lithium (Al—Li) alloy, or superalloys. The shape of the raw metal prefers to be a plate of uniform or non-uniform material. The material can be forged, progressive cold formed to form the convex base 11 or concave base 12 ( 4 a - 4 d ). According to the methods of this invention, the thin metal shell 10 is formed by stamping, forging, drawing, extruding or progressive cold forming and the thickness of the metal shell 10 formed by these methods is much smaller than that made by the die casting method. For example, the minimal thickness of the thin metal shell is 1 mm for the Mg or Al alloy formed by the current die casting method; but the minimal thickness of the thin metal shell 10 can be less than 0.3 mm for the galvanized sheet iron or stainless steel plate formed by the plastic forming technology in this invention. For the aluminum (Al) plate, the minimal thickness can be less than 0.5 mm. According to the invention, the surface of the thin metal shell 10 formed by plastic forming is rather smooth and thus the post-treatment become much easier. There is no need to do filling on the surface of the thin metal shell 10 and delicate appearance thereon can be obtained upon finishing. The plastic forming technology of this invention can be used to form the thin metal shell 10 of larger size, but the cost of the equipment and mold is less expensive in comparison with the die casting method. In addition, the scrap produced by the plastic forming technology is less than that produced by the die casting method, thereby decreasing the cost of materials.
As shown in FIG. 3 a , when the thin metal shell 10 is used as a cover, a proper bulging or sinking contour according to the layout can be plastic formed on the surface so as to increase the strength of the thin metal shell 10 . As shown in FIG. 3 b , reinforced ribs 30 can be added in the main plate 13 of the thin metal shell 10 in order to increase the mechanical strength of the thin metal shell 10 . Based on the requirements, the reinforced ribs 30 can be in the form of bars, inverse T, V, or U type at the proper place to improve the mechanical strength of the thin metal shell 10 . Preferably, the reinforced ribs 30 is made of the same material with the metal shell 10 or of the fiber reinforced composite. Then the reinforced ribs 30 are adhered with the main plate 13 of the metal shell 10 by means of the structural adhesives.
As shown in FIGS. 4 a - 4 g , the connecting components 20 might be cylinder shape connecting components including outer screw pillar, inner screw pillar, positioning pin, or plate shape connecting components including press fit pin, fastener, slot, rib, partition plate. All the connecting components 20 should be pre-machined and finished without further machining. For example, the outer thread of the outer screw pillar or the tapping of the inner screw pillar should be made in advance, then these pillars are adhered on the convex base 11 or the concave base 12 of the thin metal shell 10 via adhesives or melting method. In this way, it can eliminate the subsequent mechanical machining processes including milling, drilling and tapping applied to the die castings. The barb or inner slot of a press fit pin, fastener, slot should be made in advance, then these components are adhered to the thin metal shell 10 via adhesives or melting method. Especially, magnesium (Mg) alloy has a tendency of burning during machining, therefore there must have a special technique or equipment to proceed the machining process. According to this invention, since all the connecting components can be machined and finished in advance, it can improve the safety during work.
According to the invention, the methods of bonding the thin metal shell 10 with the connecting components 20 include application of structural adhesives, spot welding, laser welding, resistance welding or ultrasonic welding. In the following description, we will elaborate these different methods of bonding the thin metal shell 10 with the connecting components 20 .
Application of Structural Adhesives
Structural adhesives for the automobile, aerospace industries have been developed several years ago by Dow Chemical company. These structural adhesives are even stronger than the matrices that are adhered. Now, they have been applied in the automobile industry to decrease spot welding requirements. Besides, they can be applied to bond the thin metal shell 10 with connecting components 20 so as to provide enough mechanical strength to sustain stresses. The stresses mainly include the tensile stress happened on threaded components, fastener, press fit pin, etc. and compressive stress while the thin metal shell is impacted by external force, yet part of the stresses may include the bending or shearing stress happened on positioning pin, partition plate, positioning strip, etc. The structural adhesives have a better resistance to tensile stress than shear stress. However, the inferior shear stress can be overcome and improved by design skill. For instance, increasing the bonding area or transforming the shear stress into tensile stress can be used to ensure the bonding quality of the structural adhesive. In addition, combined with other mechanically aided ways of tensile resistance such as mixed use of structural adhesive and welding, and using close tolerance design can also have a reinforced effect.
The structural adhesives can be applied by utilizing the robot, automatic dispenser or surface-mount technology (SMT). There are several advantages of using robot or automatic dispenser to apply the structural adhesive. These advantages include accurate positioning and a better control of thickness and area of adhesives; however, the rate of application is relatively low. For SMT, the structural adhesive is applied to the thin metal shell through printing-like method at one time. This way is much quicker and can save time. The application of the structural adhesive can be processed in automation, while the thickness of the structural adhesive can be controlled by using certain sizes of glass beads. In the case that the thin metal shells are made of Mg alloy, Al alloy and Al—Li alloy with oxide residues on the surface, they should be cleaned or surface treated before the application of the structural adhesive in order to ensure the bonding strength.
Application of Spot Welding or Resistance Welding
In general, the method for connecting sheet material adopts the spot welding. As the size of the connecting components is usually small, especially the information electronics, therefore we can apply instantaneous heating within the bonding area by spot welding or resistance welding so as to reach the purpose of connection. The advantages of using spot welding or resistance welding include rapid and simple process as well as good bonding strength if the current is under appropriate control. However, this process is not applicable to thermo-sensitive materials, such as Mg alloy.
Application of Ultrasonic Welding
Completely differing from the methods mentioned above, the ultrasonic vibration can also be applied to the bonding area between the thin metal shell 10 and connecting components 20 . The heat created by the surface friction during ultrasonic vibration is used to bond materials. This method has the advantages of good bonding performance, simple process, and no welding speck on the surface of the thin metal shell. However, this process is not applicable to thermo-sensitive material and the thin metal shell with an oxide layer.
Application of Laser Welding
Completely differing from the methods mentioned above, laser is applied to the bonding area between the thin metal shell 10 and connecting components 20 . The instantaneous energy is created to bond materials. This method has the advantages of no welding speck, good appearance and low thermal deformation.
Ways to Put the Connecting Components on the Thin Metal Shell that has been Applied with the Structural Adhesive
Automatic inserting machine or technology can be applied to align the connecting components 20 and to feed those components to the pick-up area, then a mechanical claw or arm can be applied to pick up those components, and to move those components to the right place for bonding. If the thin metal shell 10 has the above-mentioned convex base 11 or concave base 12 , there will be a function of automatic guiding and positioning, which can decrease the stringency for accurate positioning and accelerate layout speed. Without special design for positioning as mentioned above, the current positioning technologies such as X-Y table, linear motor, etc. can still reach the positioning requirements.
As shown in FIGS. 4 e - 4 g , bonding on the folded side plate 14 of the thin metal shell 10 must be careful. In order to avoid moving and tilting of the connecting components 20 before curing of the structural adhesive, the following conditions have to be considered: 1. High viscosity adhesives. If the viscosity of the structural adhesive is high, it can prevent the connecting components from moving without external force and shipment. 2. Thermo-sensitive or temperature-sensitive adhesives. It is able to prevent the connecting components from moving or loosening if a bit of heat is added to partially harden the structural adhesive during bonding. In the case of the bonding between the folded side of the thin metal shell and the connecting components, spot welding, laser welding or ultrasonic welding can be applied for bonding without using structural adhesives. In case of the structural adhesive is applied, it has to be conductive material.
Curing Process
Curing process is the hardening process of the structural adhesive to create permanent structural strength. The components after assembly can be put into the curing oven to accelerate the hardening rate and hence decrease the processing time. If the materials of connecting components are thermo-sensitive or temperature-sensitive and cannot be baked in the oven, then the structural adhesive with higher hardening rate at room temperature will be required for alternative.
As apparent from the above description, the present invention provides a method for fabricating the thin metal shell having connecting components. This method can tremendously decrease the technical difficulty of fabricating the thin metal shell and make the subsequent surface treatment or coating become much easier, thereby lowering the manufacturing cost. For flammable alloys such as Mg alloy, the present invention can decrease the tendency of burning during melting, refining, and machining, therefore improve the safety during processing. Besides, the present invention can be used to fabricate the much larger and thinner metal shells.
Although the preferred embodiments of the invention have been disclosed for illustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as set forth in the appended claims. | A method for fabricating a thin metal shell that has connecting components is disclosed. This method comprises the following steps: forming a metal plate by plastic forming technologies into a thin shell with a plurality of bonding bases thereon; applying a structure adhesive on the bonding bases; disposing connecting components on the bonding bases with the structural adhesive; and curing the structural adhesive which bonds the shell and connecting components. | 8 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The invention is directed to an improved device for supplying fuel from a tank to an internal combustion engine.
[0003] 2. Description of the Prior Art
[0004] A fuel supply device is known from DE 196 19 992 A1, in which a fuel-supply pump is supported with its housing in a cylindrical mount and is fixed in the cylindrical mount by means of a pressurized connection fitting that is slid onto an outlet fitting of the fuel-supply pump. The cylindrical mount is also flexibly supported by noise-damping suspension elements so that noise generated by the fuel-supply pump cannot be transmitted to the tank via the mount. The pressure connection fitting is attached to a main filter of the device via a flexible tube. It is disadvantageous that the mount requires a large amount of space and is comparatively complex and costly.
OBJECT AND SUMMARY OF THE INVENTION
[0005] The device according to the invention has the advantage over the prior art in that the mount of the fuel-supply pump is simplified and in that the mount is embodied as a rigid conduit and has a first fuel supply line section that is connected to the outlet fitting of the fuel-supply pump. In this manner, the first fuel supply line section is integrated into the mount, thus reducing the number of components and reducing the production costs.
[0006] It is particularly advantageous to attach the fuel-supply pump to the mount only by means of the outlet fitting since this makes it possible to reduce the transmission of noise to the tank. It also significantly simplifies assembly.
[0007] It is also advantageous if the mount has a mount fitting with a mount conduit that feeds with an opening into the first fuel supply line section since this makes it particularly easy to fasten the outlet fitting of the fuel-supply pump in the mount conduit.
[0008] It is advantageous if the outlet fitting of the fuel-supply pump is inserted into the mount conduit and passes through a mounting element provided in the connection opening because this produces a positively engaging connection between the mounting element and the outlet fitting.
[0009] It is also advantageous if the mounting element engages in detent fashion in a mounting groove of the outlet fitting since this permits the production of a simple and reliable detent connection.
[0010] Because the fuel-supply pump is fastened to the outlet fitting only at the mounting element, it is also advantageous to make the mounting element out of an elastic material since this can significantly reduce amount of fuel-supply pump noise that is transmitted to the tank via the mount.
[0011] It is very advantageous if the mount has a first shoulder in the connection opening, against which the mounting element rests; a second shoulder fixes the mounting element against the first shoulder in cantilevered fashion. The fuel-supply pump is thus firmly fixed in the mount.
[0012] It is also advantageous to fix the mounting element against the first shoulder by means of at least one hold-down element since this also firmly anchors the fuel-supply pump in the mount.
[0013] It is additionally advantageous if the mounting element is flat and disk-shaped since this makes the mounting element particularly inexpensive to produce.
[0014] It is advantageous to embody the mounting element as a curved shaped part because this facilitates production of the detent connection.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] The invention will be better understood and further objects and advantages thereof will become more apparent from the ensuing detailed description of preferred embodiments, taken in conjunction with the drawings, in which:
[0016] [0016]FIG. 1 shows a sectional view of a device incorporating the invention for supplying fuel,
[0017] [0017]FIG. 2 shows an enlarged, fragmentary three-dimensional view of the device according to FIG. 1,
[0018] [0018]FIG. 3 shows a first exemplary embodiment of the invention,
[0019] [0019]FIG. 4 shows a fuel-supply pump with an outlet fitting according to the invention,
[0020] [0020]FIG. 5 shows a second exemplary embodiment of the invention,
[0021] [0021]FIG. 6 shows a sectional view of the second exemplary embodiment,
[0022] [0022]FIG. 7 shows a third exemplary embodiment of the invention, and
[0023] [0023]FIG. 8 shows a fourth exemplary embodiment.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0024] The fuel supply device shown in FIG. 1 serves, for example, to supply fuel from a tank 1 to a collecting receptacle 2 and from there, via a fuel-supply pump 3 , to an internal combustion engine 4 of a motor vehicle.
[0025] The tank 1 contains the collecting receptacle 2 , which in turn contains the fuel-supply pump 3 . The for example cup-shaped collecting receptacle 2 stores enough fuel to assure a sufficient supply of fuel to the internal combustion engine 4 by means of the fuel-supply pump 3 even when no fuel is being supplied into the collecting receptacle 2 , for example because the vehicle is negotiating a curve and thus causing sloshing movements of the fuel in the tank 1 .
[0026] The fuel-supply pump 3 draws fuel from the collecting receptacle 2 , for example via a prefilter 5 and an intake line 6 , and supplies the fuel to the internal combustion engine 4 , for example via a first fuel supply line section 8 . 1 , a check valve 9 , a second fuel supply line section 8 . 2 , a main filter 10 , and a third fuel supply line section 8 . 3
[0027] Starting from the third fuel supply line section 8 . 3 , an excess pressure line 13 leads to a pressure regulating valve 14 . If the pressure in the third fuel supply line section 8 . 3 and therefore in the excess pressure line 13 exceeds a preset pressure, then the pressure regulating valve 14 opens and allows fuel to flow back into the collecting receptacle 2 via the excess pressure line 13 and the pressure regulating valve 14 . This reduces the pressure in the third fuel supply line section 8 . 3 back to below the preset pressure and the pressure regulating valve 14 closes again.
[0028] For example, the fuel-supply pump 3 is a flow-type pump that is driven electrically by an actuator, for example an armature of an electric motor.
[0029] The prefilter 5 protects the device downstream of the prefilter 5 from coarse particulate matter contained in the fuel.
[0030] When the fuel-supply pump 3 is switched off, the check valve 9 prevents fuel from flowing back out of the fuel supply line ( 8 . 3 , 8 . 2 ) downstream of the check valve 9 and into the collecting receptacle 2 via the first fuel supply line section 8 . 1 , the fuel-supply pump 3 , the intake line 6 , and the prefilter 5 .
[0031] The main filter 10 filters out the fine particulate matter contained in the fuel.
[0032] The first fuel supply line section 8 . 1 is connected to the collecting receptacle 2 for example via a branch line 11 , a throttle 12 , a propulsion line 15 , and a so-called aspirating jet pump 16 .
[0033] In order to prevent the fuel-supply pump 3 from emptying the collecting receptacle 2 , there must be a continuous replenishing flow of fuel from the tank 1 into the collecting receptacle 2 . To this end, the aspirating jet pump 16 draws fuel from the tank 1 for example via a bottom valve 17 and an intake conduit 18 . The aspirated fuel is conveyed into the collecting receptacle 2 along with the so-called propulsion jet of the propulsion line 15 .
[0034] An aspiration jet pump is known, for example, from DE 198 56 298 C1, the disclosure of which is incorporated herein by reference.
[0035] The fuel-supply pump 3 has a housing with an inlet fitting 20 and an outlet fitting 21 . The intake line 6 is connected to the inlet fitting 20 , while the outlet fitting 21 is connected to the first fuel supply line section 8 . 1 .
[0036] [0036]FIG. 2 shows a three-dimensional view of the device according to the invention from FIG. 1.
[0037] In the device according to FIG. 2, parts that are the same or function in the same manner as those in the device according to FIG. 1 are provided with the same reference numerals.
[0038] The fuel-supply pump 3 is fastened to a mount 27 that is embodied as a rigid conduit. The mount 27 contains the first fuel supply line section 8 . 1 . The end of the mount 27 oriented toward the main filter 10 is connected to the main filter 10 . The length of the mount 27 extends beyond the edge of the main filter 10 in the direction of the fuel-supply pump 3 . The fuel-supply pump 3 is fastened into the mount 27 by means of a detent connection.
[0039] [0039]FIG. 3 shows a partial section through a first exemplary embodiment.
[0040] In the device according to FIG. 3, parts that are the same or function in the same manner as those in the device according to FIGS. 1 and 2 are provided with the same reference numerals.
[0041] For example, the fuel-supply pump 3 has a housing 22 with a cylindrical housing section 23 , whose end oriented toward the inlet fitting 20 is sealed shut by a pump cover and whose end oriented toward the outlet fitting 21 is sealed shut by an outlet cover 24 .
[0042] The end of the mount 27 oriented toward the fuel-supply pump 3 has a mount fitting 28 that is cylindrical, for example. The mount fitting 28 has a mount conduit 25 that feeds from the end of the mount fitting 28 oriented toward the fuel-supply pump 3 , through a connection opening 31 , and into the first fuel supply line section 8 . 1 . The cross section of the mount fitting 28 is slightly greater than the cross section of the outlet fitting 21 of the fuel-supply pump 3 so that the outlet fitting 21 can be slid into the mount conduit 25 of the mount fitting 28 . At the end oriented toward the fuel-supply pump 3 , the mount fitting 28 has a first bevel 32 to facilitate the insertion of the outlet fitting 21 . The cross section of the mount fitting 28 is circular, for example.
[0043] The outer circumference of outlet fitting 21 of the fuel-supply pump 3 has an annular sealing groove 29 in which a sealing ring 30 , for example an O-ring, is provided. Downstream of the sealing groove 29 , a number of pocket-shaped recesses 33 are provided on the outer circumference of the outlet fitting 21 , for example distributed over its circumference. Further downstream of the pocket-shaped recesses 33 , the outer circumference of the outlet fitting 21 is provided with a mounting groove 34 that extends around its entire circumference. The mounting groove 34 is round, for example, or is embodied as a square groove (FIG. 4). The outlet fitting 21 is provided with a conical bevel 38 at its end oriented away from the outlet cover 24 .
[0044] The cross section of the first fuel supply line section 8 . 1 is composed, for example, of a rectangle 36 and a circular or arcuate segment 37 . The cross section of the first fuel supply line section 8 . 1 , however, can also be composed of only the circular segment 37 , or can be entirely circular, rectangular, or elliptical.
[0045] The transition from the mount fitting 28 to the first fuel supply line section 8 . 1 forms a first shoulder 35 . The first shoulder 35 is adjoined by second shoulder 39 that is of one piece with it and embraces a mounting element 41 that rests against the first shoulder 35 in cantilevered fashion. The second shoulder 39 fixes the mounting element 41 on the first shoulder 35 . A width 43 of the rectangle 36 in the vicinity of the connection opening 31 is greater than a diameter 44 of the circular segment 37 so that the first shoulder 35 and the second shoulder 39 together constitute an indentation 40 .
[0046] For example, the mounting element 41 is embodied as disk-shaped. The mounting element 41 is polygonal, for example square, hexagonal, or octagonal, with respective pairs of parallel sides; two parallel, opposing sides rest against the second shoulder 39 so that the mounting element 41 is supported in a non-rotating fashion in the first fuel supply line section 8 . 1 . The mounting element 41 can, however, also be circular or elliptical. The mounting element 41 is made of an elastic material, for example rubber.
[0047] The mounting element 41 has a for example square opening 42 that is smaller than the connection opening 31 . The opening 42 , however, can also be circular or polygonal.
[0048] The mounting element 41 is slid into the indentation 40 through a lateral conduit opening 47 . The width 43 of the rectangle 36 is reduced in step fashion in the axial extension of the first fuel supply line section 8 . 1 , thus forming a stop for the mounting element 41 . The stop centers the mounting element 41 in relation to the connection opening 31 of the mount fitting 28 so that the opening 42 of the mounting element 41 is concentric to the connection opening 31 . After the insertion of the mounting element 41 , a side cover 46 closes the lateral conduit opening 47 .
[0049] In order to attach the fuel-supply pump 3 to the mount 27 , the outlet fitting 21 of the fuel-supply pump 3 is slid into mount fitting 28 provided with the mounting element 41 . The outlet fitting 21 is pushed, with its bevel 38 first, through the opening 42 of the mounting element 41 . As a result, first the bevel 38 elastically stretches the opening 42 until it is the same size as the outer diameter of the outlet fitting 21 and then the outlet fitting 21 travels further through the opening 42 until the mounting groove 34 of the outlet fitting 21 reaches the opening 42 . Since the outer diameter of the outlet fitting 21 decreases in step fashion at the mounting groove 34 , the elastically stretched opening 42 contracts again, fits elastically into the inner diameter of the mounting groove 34 , and thus engages in the mounting groove 34 in detent fashion. As a result, the outlet fitting 21 extends through the opening 42 of the mounting element 41 as it engages in the mount fitting 28 . This detent connection attaches the fuel-supply pump 3 to the mount 27 . If the opening 42 is square and the mounting groove 34 is a square groove, then this produces a non-rotating detent connection.
[0050] The mounting element 41 absorbs virtually all of the forces acting in the direction of the mount fitting 28 , for example the weight of the fuel-supply pump, and transmits them to the mount 27 . The elasticity of the mounting element 41 damps both mechanical vibrations and acoustical vibrations. Consequently, hardly any acoustical vibrations (noise) that are generated by the fuel-supply pump 3 are transmitted by mounting element 41 to the mount 27 , thus permitting a reduction in the audible noise level of the fuel-supply pump 3 in the vehicle.
[0051] The sealing ring 30 in the sealing groove 29 seals a gap between the outlet fitting 21 and the mount fitting 28 so that, for example, no fuel can escape from the first fuel supply line section 8 . 1 to the outside.
[0052] [0052]FIG. 4 shows the fuel-supply pump 3 with the outlet fitting 21 .
[0053] In the device according to FIG. 4, parts that are the same or function in the same manner as those in the device according to FIGS. 1 and 3 are provided with the same reference numerals.
[0054] The outlet fitting 21 can have additional pocket-shaped recesses 56 distributed over the circumference of its bevel 38 .
[0055] [0055]FIG. 5 shows a second exemplary embodiment of the device according to the invention, without a fuel-supply pump 3 .
[0056] In the device according to FIG. 5, parts that are the same or function in the same manner as those in the device according to FIGS. 1 to 4 are provided with the same reference numerals.
[0057] The device according to FIG. 5 differs from the device according to FIG. 3 in that a centering plate 45 disposed perpendicular to the side cover 46 positions the mounting element 41 centrally in relation to the connection opening 31 .
[0058] As in the exemplary embodiment according to FIG. 3, after the insertion of the mounting element 41 , the side cover 46 covers the lateral conduit opening 47 of the mount 27 and seals it off from the environment. The centering plate 45 disposed on the side cover 46 has for example protruding centering means 48 that are disposed, for example, uniformly distributed around the circumference of an additional opening 52 in the centering plate 45 . The additional opening 52 in the centering plate 45 is larger than the opening 42 of the mounting element 41 . The mounting element 41 is slid onto the centering plate 45 of the side cover 46 ; the centering means 48 , for example centering pins or centering ribs, engage in centering openings 49 of the mounting element 41 .
[0059] The centering plate 45 is slid with the mounting element 41 into the indentation 40 of the mount 27 until the side cover 46 closes the side conduit opening 47 . After the insertion, the centering plate 45 is approximately parallel to the first shoulder 35 . The mounting element 41 rests against the shoulder 35 . For example, the side cover 46 is welded to the mount 27 . However, the side cover 46 can also be glued or flange-mounted to the wall of the lateral conduit opening 47 .
[0060] Then the outlet fitting 21 of the fuel-supply pump 3 can be slid into the mount fitting 28 . The centered mounting element 41 permits the outlet fitting 21 to reliably and simply engage in detent fashion in the mount 27 , as described above.
[0061] [0061]FIG. 6 shows the second exemplary embodiment in a partial sectional view, with the outlet fitting 21 of the fuel-supply pump 3 detent engaged in the mount 27 .
[0062] In the device according to FIG. 6, parts that are the same or function in the same manner as those in the device according to FIGS. 1 to 5 are provided with the same reference numerals.
[0063] After being inserted, the outlet fitting 21 engages in detent fashion in the mount fitting 28 and reaches through both the opening 42 and the additional opening 52 . In order to accommodate the centering plate 45 , the indentation 40 is taller in the direction of the mount fitting 28 than the indentation 40 in the first exemplary embodiment according to FIG. 3.
[0064] [0064]FIG. 7 shows a partial sectional view of a third exemplary embodiment.
[0065] In the device according to FIG. 7, parts that are the same or function in the same manner as those in the device according to FIGS. 1 to 6 are provided with the same reference numerals.
[0066] The device according to FIG. 7 differs from the device according to FIG. 3 in that the mounting element 41 is fixed against the first shoulder 35 not by the second shoulder 39 , but by hold-down elements 55 . The second shoulder 39 is eliminated in this third exemplary embodiment.
[0067] The mount 27 is divided in the axial direction and is comprised of an upper part 53 with the circular segment 37 and a lower part 54 with the mount fitting 28 and the first shoulder 35 . The hold-down elements 55 are disposed on the side of the upper part 53 oriented toward the lower part 54 , protrude toward the first shoulder 35 of the lower part 54 , and rest against the mounting element 41 so that the mounting element 41 is fixed against the first shoulder 35 .
[0068] The division in two of the first fuel supply line section 8 . 1 makes it possible for the holding element 41 to be inserted into the lower part 54 of the mount 27 . After the insertion of the mounting element 41 , the upper part 53 is slid into the lower part 54 and, for example, welded or glued in place. However, the upper part 53 and the lower part 54 can also be clipped to each other. A separate side cover 46 is not required since it is already formed onto the upper part 53 or the lower part 54 .
[0069] [0069]FIG. 8 shows a sectional view of a fourth exemplary embodiment.
[0070] In the device according to FIG. 8, parts that are the same or function in the same manner as those in the device according to FIGS. 1 to 7 are provided with the same reference numerals.
[0071] The device according to FIG. 8 differs from the device according to FIG. 7 in that the mounting element 41 is not embodied as flat, but as a curved shaped part. To this end, the elastic mounting element 41 is produced, for example, by means of injection molding. An inner region 59 of the mounting element 41 encompasses the opening 42 ; an outer region 60 constitutes the outer circumference of the mounting element 41 and is spaced apart in the axial direction from the inner region 59 due to the curvature of the mounting element 41 .
[0072] The mounting element 41 rests with its inner region 59 in the mounting groove 34 and rests with its outer region 60 against the first shoulder 35 . The mounting groove 34 is embodied as longer in the direction of the outlet fitting 21 than those according to FIGS. 3, 5, 6 , and 7 since starting from the inner region 59 , the mounting element 41 in the mounting groove 34 extends first in the direction of the outlet fitting 21 and then curves outward in the direction of the first shoulder 35 . The hold-down elements 55 protrude in the direction of the first shoulder 35 and press the inner region 59 into the mounting groove 34 while pressing the outer region 60 of the mounting element 41 against the first shoulder 35 . The inner region 59 of the mounting element 41 rests against an upper side surface 61 of the mounting groove 34 . The forces of the fuel-supply pump 3 act on the inner region 59 of the mounting element 41 via the upper side surface 61 and are transmitted to the mount 27 via the first shoulder 35 .
[0073] The foregoing relates to preferred exemplary embodiments of the invention, it being understood that other variants and embodiments thereof are possible within the spirit and scope of the invention, the latter being defined by the appended claims. | A device for supplying fuel from a tank in which the mount of the fuel-supply pump, in which the mount is simpler and less expensive than the known devices because the number of components is reduced through the integration of functions. The mount of the fuel-supply pump is embodied as a rigid conduit and has a first fuel supply line section that is connected to the outlet fitting of the fuel-supply pump. The transmission of noise to the mount is reduced. | 5 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention concerns an apparatus for relocating the stocking toe part in the right position when it is put incorrectly on a setting frame of a finishing machine. More particularly, this invention concerns an apparatus for automatically relocating the stocking toe part in the right position when it is mis-placed on a setting frame of a finishing machine by causing a seam locator to find a seam on the stocking toe part and then causing a relocating means to bring the stocking toe part to the given right position.
2. Description of the Prior Art
In conventional automatic stocking-setting apparatuses, a variety of disclosures have already been published and some of them have actually been put into practice. Among them, there are an apparatus that enables workers to mount a number of stockings on a setting frame at one time and an apparatus that can automatically mount many pairs of stockings on a setting frame one after another.
Commonly those apparatuses have a holder to inflate stockings from the inside. Besides, they are designed in such a way that stockings can completely fit on a setting frame while the holder is being lowered from the top to the bottom of the setting frame. Nevertheless, because stockings do not fit on a setting frame very well, a device for pushing them down on the setting frame has also been developed.
Such being the case, according to those recent automatic stocking mounting apparatuses, workers only have to do is bring stockings to a holder with their opening widened; then, the rest of the work is all finished in an automatic manner. Thus, the working efficiency is improved very much with the result that the exhaustion of workers is considerably reduced, and this results in increasing the productivity of a finishing machine.
For all that such a series of automated processes have accomplished, the stocking toe part is not always fixed to a given part of a setting frame; on the contrary, it is much more frequently misplaced than placed in the right position.
As FIG. 5 shows, stockings H (especially, hosiery such as women's seamless stockings and pantyhose) already have a circular seam S at the toe part before undergoing steam-setting in a finishing machine; hence, the top of a setting frame F is shaped so as to fit to the circular seams. Therefore, when stockings H are put on the setting frame F, the circular seam S has to be put on its top T correctly. If the circular seam S is not on its top T in the right position as seen in FIGS. 6 and 7, the stocking toe part will be set in a twisted position in relation to its leg part L. Consequently, the merchandise value of those stockings H is greatly reduced; in addition, those who wear them may feel uneasy. From these points of view, such stockings H need re-setting. However resetting requires careful handwork. Thus, in conventional hosiery workshops, many workers entirely engaged in resetting are required. Accordingly, even if an automatic stocking mounting apparatus is introduced, the merit resulting therefrom is decreased by half, so that improvement in such labor-intensive work has long been awaited.
SUMMARY OF THE INVENTION
It is an object of this invention to provide an apparatus for automatically relocating the stocking toe part correctly on a setting frame. It is another object of this invention to provide an apparatus for automatically relocating the stocking toe part correctly on a setting frame with which full automation of the stocking finishing process is realized. It is still another object of this invention to provide an apparatus for automatically relocating the stocking toe part correctly on a setting frame (hereinafter referred to as an automatic stocking relocating apparatus) by which a hosiery of high merchandise value can be produced. The above and other objects and features of this invention will appear more fully hereinafter from a consideration taken in connection with the accompanying drawing wherein one example is illustrated.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a partially cutaway side view of an automatic stocking relocating apparatus of this invention.
FIG. 2 is a front view of the same apparatus of this invention.
FIG. 3 is a transversally cutaway view of the same apparatus taken along the line X--X in FIG. 2.
FIG. 4 is an enlarged plan view of a seam locator of the same apparatus.
FIGS. 5, 6 and 7 are illustrations showing stockings mounted on a setting frame, where FIG. 5 shows a condition that a stocking is put on a setting frame correctly; FIGS. 6 and 7 show a condition that stockings are put on a setting frame incorrectly, with the result that their seam gets out of the circular top of the setting frame.
FIG. 8 is a plan view showing the arrangement of the automatic stocking relocating apparatus of this invention in relation to a finishing machine.
FIGS. 9 and 10 are plan views showing another example of the automatic stocking relocating apparatus of this invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
In order to help the understanding of this invention, first of all the outline of a commonly used stocking finishing machine will be described and then the disposition of the automatic stocking relocating apparatus will be related in regard to the finishing machine.
In FIG. 8, the numeral 10 designates a steam setter; the numeral 11 designates a dryer; the numeral 12 designates a device for taking out stockings; and the numeral 13 designates a device for mounting stockings on setting frames; all of which are disposed on an endless conveyor 14. The automatic stocking relocating apparatus 20 of this invention is installed after the mounting device 13 in terms of the circulating direction of the conveyor 14. A plurality of carriages 15 constructed of a pantographic framework that holds a plurality of stocking-setting frames F in the upright position are fixed on the endless conveyor 14 and they are moved in the arrow-headed direction a by means of an appropriate driving apparatus (not shown here). Hence, stockings held in the carriages 15 are subjected to steam-set at the steam-setter 10, dried at the dryer 11 and then taken out at the taking-out device 12. After stockings have been taken out, the carriages 15 are transferred to the mounting device 13 where yet steam-untreated stockings are mounted on the setting frames F of the carriages 15. After each of the stockings is mounted on each setting frame F, the carriages 15 leave the mounting device 13 and the setting frames F advance on the conveyor 14, increasing their mutual distance by the deployment action of the carriage 15 and making a stop intermittently. At this moment, the automatic stocking relocation apparatus 20 of this invention is used to replace a stocking toe part correctly on the setting frame F at the time the carriage 15 is making a stop for a while.
The construction of the automatic stocking relocating apparatus will be described in detail with reference to the accompanying drawings.
As stated above, the automatic stocking relocating apparatus 20 of this invention is disposed after the mounting device 13 in terms of the turning direction of the conveyor 14 in such a way that the setting frames F can pass through thereunder increasing the distance from the one going ahead and making intermittent stops. In FIGS. 1, 2 and 3, just above the setting frames F traveling on the conveyor 14, a base plate 21 is supported horizontally by stays (not shown here). A couple of swingable members 30, 130 having a framework as shown in FIG. 2 dangle from the shafts 31, 131 in such a way that they can hold a setting frome F from both sides. Fastened to the same end of the shafts 31, 131 are fan-shaped gears 32, 132 meshing with each other, and a piston 22a of an air cylinder 22 is joined to one gear 32 of the gears. The upper part of the pneumatic cylinder 22 is pivotally attached to an arm of a bracket 23 with a pin 24. Thus, as the piston 22a moves ups and downs by means of the pneumatic cylinder 22, the shafts 31, 131 rotate by way of the fan-shaped gears 32, 132 and a pair of swingable members 30, 130 make a swinging movement between the position in operation (shown by a solid line in FIG. 1) and the position out of operation (shown by a chain line in FIG. 1). The swingable members 30, 130 are usually kept on standby in the position out of operation.
A pair of relocating means 33, 133 used to correct the position of the stocking toe part T on a setting frame F is attached to the swingable members 30, 130. As shown in FIG. 1, a pair of vertical, parallel shafts 34, 134 are fixed between horizontal frames 30a, 30b and between horizontal frames 130a, 130b so as to be rotatable with the aid of bearings 35, 135. A pair of relocating means 33, 133 in the form of a roller, the surface of which is covered with a wear-resistant, frictional synthetic rubber, for example, as shown in FIG. 3 is fitted on the vertical, parallel shafts 34, 134. Moreover, a pair of gears 36, 136 is fastened to the upper ends of the shafts 34, 134 which project upward out of the horizontal frames 30a, 130a. A motor 25 is installed on the base plate 21; an output shaft 25a of the motor 25 is made to project downward out of the base plate 21; a gear 26 is fastened to the output shaft 25a. The structure being is such that, when the swingable members 30, 130 swing inward to the position in operation, they can hold a setting frame F on both sides and the gears 36, 136 can mesh with the gear 26 fixed to the output shaft 25a of the motor 25. Thus, when the motor 25 starts, the relocating members 33, 133 are rotated by way of the gears 36, 136. More particularly, when the motor 25 rotates in the positive direction, the relocating members 33, 133 rotate clockwise as shown by an arrow-headed mark in FIG. 3; when the motor 25 rotates in the negative direction, they rotate counter-clockwise.
In connection with the rotation, the motor 25 may be a pulse motor of conventional type whose drive can be put under control of signals transmitted from a device 40 for locating a seam of the stocking toe part, as described in the following discussion.
As shown in FIGS. 1, 2 and 3, the seam locater 40 is provided on the side of one member 130 of the swingable members 30, 130. Specifically, the seam locator 40 is attached to a piston 52a of a small pneumatic cylinder 52 that is supported by a bracket 51 fixed to the under surface of the horizontal frame 130a (FIGS. 1 and 2). As apparent in FIG. 1, the seam locator 40 can move forward and backward by the action of the small pneumatic cylinder 52 when the swingable members 30, 130 are in the position in operation. Thus, the seam locator 40 can touch one side (for example, the top side) of the setting frame F and get away from it.
The numeral 53 in FIGS. 2-4 designates a guide shaft, one end of which is fixed to the seam locator 40, which is fitted into a bracket 54 provided on the under surface of the horizontal frame 130a (FIGS. 1 and 2); thus, the shaft 53 serves as a guide for the seam locator 40 which moves back and forth.
The seam locator 40 will be explained in more detail with reference to FIG. 4. Fixed on the bottom of a plate 41 are the piston 52a of the small pneumatic cylinder 52 and the guide shaft 53. Provided on the top side of the plate 41 are a good number of electrodes 42 circuited in parallel at a given interval in the longitudinal direction of the plate 41. They are covered with a sheet of piezoelectric conductive rubber 43 (for example, a piezoelectric conductive composite material made up of silicon rubber and a metal powder). A protective sheet 44 like a metal foil is applied on the sheet 43 so as to make up the whole seam locator 40 as a single switch element. The seam locator 40 has such a construction that part of the rubber sheet 43 becomes discontinuous where a pressure of more than a limit is applied on the protective sheet 44, whereas the other part where the pressure is not applied stays insulated. As a result of the occurrence of the partial continuity, a driving pulse generates from an oscillation circuit (not shown here). The driving pulse is then converted into a predetermined frequency by means of a dividing circuit (not shown here) so that it can be accepted by the pulse motor 25. At this moment, the motor 25 is put under control based on the program stored in the electrodes 42.
In relation to the above, in this example a number of the circuited electrodes 42 on the top side of the plate are divided into two blocks: A and B for example. The motor 25 is controlled so as to rotate in the positive direction when the electrodes in the block A get into continuity and rotate in the negative direction when the electrodes 42 in the block B complete a circuit.
Moreover, the number of the electrodes 42 in the block A is identified as A 1 , A 2 , . . . A n and the number of the electrodes 42 in the block B is identified as B 1 , B 2 , . . . B n , whereby the motor 25 is caused to rotate in the positive direction for as many rotations as possible for two pulses when one electrode A 2 in the block A complete a circuit, for example. Similarly, the motor 25 is caused to rotate in the negative direction for as many rotations as possible for three pulses when one electrode B 3 in the block B completes a circuit, for example.
As stated above in regard to FIG. 8, a group of yet steam-untreated stockings H put on the setting frames F start increasing their mutual interval as soon as they get out of the mounting device 13. They move and stop intermittently toward the steam setter 10 on the conveyor 14 and while they are making a stop, the automatic stocking relocating apparatus 20 of this invention conducts the relocation of the stocking toe part. The setting frames F put in the deployment position make an advance and a stop intermittently; they stop for a while at a position and function as shown in FIGS. 1 and 2. Their stop is sensed by an appropriate detector like a limit switch. The pneumatic cylinder 22 of FIG. 1 moves receiving the sense and causes the swingable members 30, 130 to swing from the position out of operation to the position in operation. In association with the movement of the swingable members 30, 130, the gears 36, 136 are engaged with the driving gear 26 and the relocating members 33, 133 are pressed against both sides of a setting frame F at the toe part of a stocking. Subsequently, the seam locator 40 moves forward by the action of the small pneumatic cylinder 52 and presses the piezoelectric conductive rubber sheet 43 of FIG. 4, covered with the protective sheet 44, against one side of the stocking toe part T. A seam makes a line of protrusion on the knit of the stocking; thus, if the seam is put on the verge of the setting frame F correctly, there is no line of protrusion on the side where the piezoelectric conductive rubber sheet 43 is pressed; therefore, the seam locator 40 can find no seam there. Accordingly, the relocating means 33, 133 do not move; the swingable members 30, 130 return to the position out of operation by the reverse action of the pneumatic cylinder 22; thus, the setting frame F is allowed to pass the gate.
If, however, a seam is mis-placed deviating from the correct position as FIG. 6 shows, in terms of the center line O (in this case, the part of the seam on the other side of the setting frame F lies nearly symmetrical with the part of the seam S on this side), the part of the piezoelectric conductive rubber sheet 43 correspondent to a line of the protruded seam is pressed more strongly than the other part by the same seam. On account of this pressure, those electrodes 42 in line with the pressure complete a circuit so as to allow the apparatus to operate and relocate the seam. At this moment, if the A 5 electrode in the A block completes a circuit, the motor 25 rotates for five pulses in the positive direction.
The seam locator 40 moves backward by the reverse action of the small pneumatic cylinder 52 before the motor 25 starts rotating and keeps away from the stocking toe part T. Meanwhile, the relocating members 33, 133 rotate in the arrow-headed direction (clockwise) in FIG. 3 by means of the gears 26, 36, 136 of FIG. 1 in association with the rotation of the motor 25 in the positive direction. Because the relocating members 33, 133 hold a stocking, together with a setting frame F, the toe part T of the stocking on this side of the setting frame F moves to the right and the toe part T of the stocking on the other side of the setting frame F moves to the left in terms of FIGS. 3 and 6 when the relocating members 31, 133 rotate in the above direction. By the reciprocal rotation of the relocating members 33, 133 the seam S on the stocking toe part T is relocated to the circular end of the setting frame F. Now that the relocation is made by the seam locator 40 and the relocating members 33, 133 in a strictly controlled manner, the seam S on the stocking toes part T is put correctly on the circular end of the setting frame F.
FIG. 7 shows that a seam S is mis-placed in terms of the center line O; the seam S on this side of the setting frame F deviates to the left (and the seam S on the other side to the right nearly symmetrically). In this case, any electrode B 1 , B 2 , . . . B n in the block B gets pressed by a line of the protruded seam S and tells the location of the seam S. When the location of the seam S is told, the motor 25 rotates in the reverse direction for pulses settled in a pressed electrode, which makes the relocating members 33, 133 turn the other way around as shown in FIG. 3. As a result, the seam S on this side moves to the left and the seam S on the other side moves to the right in terms of FIGS. 3 and 7, with the result that the seam S is put on the circular end of the setting frame F correctly.
To sum up, the automatic stocking relocating apparatus of this invention moves the seam S on this side to the right when it is mis-placed to the right in terms of the center line O, and moves the seam S on this side to the left when it is mis-placed to the left in terms of the center line O. For this reason, the relocation can be made rapidly and correctly.
When the relocation of the stocking toe part has thus been finished, the swingable members 30, 130 return to the position out of oparation by the reverse action of the pneumatic cylinder 22, which results in getting the relocation members 33, 133 away from the setting frame F. A setting frame F next to this one stops at the same place and undergoes the same relocation procedure.
FIGS. 9 and 10 show another example of the relocation members. FIG. 9 shows relocating members 233, 333 constructed of a couple of belts instead of a couple of rollers. FIG. 10 shows relocating members 433, 533 constructed of a pair of racks and a pinion engaged therewith.
The two types of relocating members are equally provided for the swingable members 30, 130. Those couples of relocating members 233, 333; 433, 533 are similarly engaged in the relocation of the stocking toe part; they move in the arrow-headed direction or the direction reverse thereto by the action or the reverse action of the motor 25 by way of the gear 26 and the gears 36, 136, as shown in FIGS. 9 and 10.
Being constructed of belts or racks, those types of relocating members 233, 333, 433, 533 have a considerably larger contact surface in regard to the stocking toe part compared with the roller type ones. Therefore, they are convenient for moving a seam of the stocking toe part. For reference, the relocating members 433, 533 are constructed of racks and are unable to make an endless movement, so the racks have to be returned to the original position from which they have moved in the relocation after the swingable members 30, 130 swing back to the position out of operation.
The above description is made about a system in which setting frames make an intermittent stop while they are advancing on a circular conveyor and the relocation of the stocking toe part is made during the stop. However, the automatic stocking relocating apparatus of this invention is not always restricted to this system only. It can also be applied to another system in which setting frames move continuously on the conveyor. In such a case, the stays supporting the present apparatus 20 are designed to move at the same speed as the conveyor 14 in order that the relocation of the stocking part may be made while the two are moving together in parallel, provided the stays are also designed to return to the original position right after the relocation has been made.
In addition, the above description applies to a case where a pulse motor is used to drive the relocation members but the automatic stocking relocating apparatus of this invention is not always limited to the employment of a pulse motor only. That is, a conventional small motor for all purposes can also be used in a similar manner. In such a case, the motor has to be controlled by means of a timer or the like based on signals transmitted from the seam locator 40.
As described above, the automatic stocking relocating apparatus of this invention is a result of success in inventing a seam locator for the stocking toe part and combining it with a pair of relocating members which automatically make the relocation of the stocking toe part with correctness on a setting frame. Thus, it is the case that the relocating job, conventionally made with the hands, has become replaced with the automatic stocking relocating apparatus of this invention and a fully automated system can be accomplished by providing the present apparatus for a conventional stocking finishing machine. Therefore, in view of the current stocking production, it seems most useful and desirable to use the present apparatus as auxiliary equipment for a stocking finishing machine provided with an automatic stocking feeding device. Additionally, the relocation is made by such a seam locator and relocating members in a well designed automatic fashion that the stocking toe part can be repositioned correctly on the circular end of a setting frame even if it may be mis-placed originally on the setting frame. | This apparatus automatically relocates the stocking toe part correctly on a setting frame prior to steam setting when the toe part is misplaced. The apparatus essentially comprises a pair of relocating members and a seam locator: the relocating members hold the stocking toe part together with a setting frame from both sides; the seam locator, essentially composed of a number of electrodes and a sheet of piezoelectric conductive rubber, locates a misplaced seam line by its protrusion on the setting frame and causes the relocating members to slip the seam line transversally to a certain extent on the setting frame so as to correct its position. Thus the magnitude of slip is determined by the relative position of the seam line and by one of the electrodes which has sensed the protrusion of the seam line so that the apparatus may automatically relocate the stocking toe part correctly on the setting frame. | 3 |
RIGHTS OF THE GOVERNMENT
The invention described herein may be manufactured, used, and licensed by or for the United States Government for governmental purposes without the payment to me of any royalty thereon.
BACKGROUND OF THE INVENTION
The present invention relates generally to fuzes, and more particularly to an improved joint for preventing the relative rotation of the base and cap of the fuze during static and dynamic conditions.
A major concern of fuze designers is to prevent the relative rotation of the base and cap of a fuze under the influence of angular acceleration force during firing. The fuzes of the prior art have generally included adjacent annular engaging surfaces perpendicular to the axis of rotation, said surfaces being substantially smooth. To prevent rotation of the members relative to each other during firing, the frictional engagement of the smooth surfaces has been increased. A typical example of a method to increase the frictional engagement of the rotational parts is illustrated in U.S. Pat. No. 2,216,862. A sinuous resilient band is positioned in mutually registered annular grooves in the adjacent surfaces. The band provides radial force sufficient to increase frictional engagement between the relatively movable parts.
When dealing with smooth engaging surfaces of the members of a fuze of the prior art, the friction inducing elements require a torque of approximately 150 inch-pounds or greater to rotate the members relative to each other to set the fuze in a static condition. Because of the smooth surfaces, this degree of torque is needed to reduce relative motion of the parts during firing. Thus, prior art fuzes are difficult to set and relative motion of the parts is not entirely eliminated during firing. Thus, there exists a need for a fuze joint which is capable of preventing relative movement of the two members of a fuze under the influence of angular acceleration during firing as well as requiring a minimum amount of torque to set the fuze under static conditions.
A SUMMARY OF THE INVENTION
An object of the present invention is to provide a fuze which may be set by the use of low torque.
Another object of the present invention is to provide a fuze which may be easily set by low torque while still being capable of preventing relative movement of the parts during firing conditions.
A further object of the present invention is to provide a non-slip turning joint for a fuze which requires fewer parts than prior fuze devices.
These and other objects of the present invention are accomplished by using the combination of interlocking serrated mating surfaces for the relatively movable members, a sinusoidal split ring and an inclined wall of the outer annular recess for the split ring. The axially interlocking, annular, serrated surfaces of the two rotably connected members of the fuze in combination with setback forces during firing prevent relative rotational movement of the two members during firing. The radially sinusoidal, split ring being compressed against the inclined wall of the annular recess of the inner face of the outer member produces an axial force biasing the interlocking serrated surfaces together so as to require a minimum of 40 inch-pounds torque to rotate the members relative to each other under static conditions.
The objects, advantages and novel features of the present invention will become apparent from the following detailed description of the present invention when considered in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a segmented, cutaway view of a fuze incorporating the nonslip turning joint according to the principles of the present invention.
FIG. 2 is a plane view of a sinusoidal split ring used in FIG. 1.
FIG. 3 is a cross-sectional view of a second embodiment of the sinusoidal split ring.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
A fuze, as illustrated in FIG. 1, includes a base 10 and rotatable setting cap 12. A roughened annular surface 14 of base 10 interlocks with a roughened adjacent annular surface of cap 12. Although the roughened surfaces 14 and 16 are illustrated as serrated teeth, any roughened surface requiring relative axial movement between the surfaces to effectuate rotation of the surfaces relative to each other, may be used. It should be noted that the roughened surfaces 14 and 16 are perpendicular to the axis of rotation of the body 10 and cap 12 relative to each other.
The cap 12 includes an annular recess 18 on the outer surface thereof, and the base 10 includes an annular recess 20 on the inner surface thereof, concentric and adjacent to the annular recess 18 of the cap 12. The wall 22 of annular recess 20, which is furthest from the mating roughened surfaces 14 and 16, is inclined. Resting within the annular recesses 18 and 20 is a split snap ring 24. As illustrated specifically in FIG. 2, the split ring 24 has a plurality of sinusoidal sections in the radial direction thereof. The sinusoidal shape not only increases the resilient action of the snap ring, but also allows the snap ring to simultaneously contact the interior of recesses 18 and 20. Although the split ring 24 illustrated in FIG. 2 includes six complete sinusoidal waves, any number of waves may be used as long as it provides the appropriate force to be described below. A nonsinusoidal ring was tried, but did not provide sufficient axial force.
The cap 12 includes a second annular recess 26 on the outer surface thereof, and an O-ring seal 28 therein. The O-ring 28 seals the joint between the base 10 and the cap 12.
The operations of the elements of the fuze of the present invention cooperate to prevent relative movement of the base 10 and cap 12. The interlocking roughened or serrated surfaces 14 and 16 of the base and cap require relative axial movement or displacement to effectuate a rotational movement or displacement. Although a torque force of generally 350 foot-pounds may be experienced by the fuze during firing, the set-back forces along the axis of rotation is sufficient in combination with the serrated edges to prevent relative rotational movement of the cap and the base. In the prior art, the use of smooth mating surfaces required extensive mechanisms to increase the frictional engagement of the two members. Thus the locking serrated edges take advantage of the set-back axial force produced in firing.
The split ring 24 in combination with the inclined surface 22 provides the needed axial force during the static condition of the fuze to define a minimum torque required to cause the serrated edges to ride up over each other, thereby producing rotational and axial movement of the cap relative to the base. Since the interlocking serrated mating surfaces take advantage of the setback force in the dynamic loading conditions, the split ring 24 need not produce an axial force as great as that required by prior art biasing means for smooth mating surface joints. Prior art devices have generally been designed to require a static loading of a minimum of 115 inch-pounds of torque in addition to setback forces to reduce relative motion of the smooth surfaces during firing. Thus in a static condition a minimum of 150 inch-pounds of torque is needed to set the fuze by rotation of the cap relative to the base. The fuze of the present invention has been designed to require a torque of 50 inch-pounds in the static position to turn the cap relative to the base since the setback forces are sufficient in combination with the serrated surface to prevent relative motion during firing. Preferably, the axial force should be sufficient to require a minimum torque of 40 inch-pounds to rotate the members relative to each other. This would put it out of the range of most human beings without the use of a tool. It is this requirement that makes the fuze resistant to turning during a normal handling.
To set the fuze under static conditions, a tool is applied to the exterior of the cap so as to rotate the cap relative to the base. As the cap is moved, the serrated surface 16 rides up over the serrated surface 14 axially displacing the cap 12 relative to the base 10. This axial movement also axially displaces the split ring 24 causing the outer edge to ride up the inclined surface 22. As the split ring 24 moves up the inclined surface 22, the split ring 24 is forced inward compressing the waves in the ring. It is this compressional force which defines the minimum torque required to produce axial displacement so as to allow rotational movement of the cap 12 relative to the base 10. The compression on split ring 24 is a function of the inclined surface 22 and is increased and decreased as the serrated surface 16 rides up and down over the serrated surface 14. Once the torque is removed, the split ring 24 expands radially riding down the inclined surface 22 and thereby automatically applying force in the axial direction to cause the serrated surface 16 to ride down into mating contact with the serrated surface 14.
It should be noted that by the use of the serrated surfaces 14 and 16, audible and tactile feedback of the rotation of the cap 12 relative to the base 10 is provided. This audible and tactile feedback allows the setting of the fuze in total darkness.
Although the split ring 24 is illustrated as having a rectangular cross-section, the outer top edge of the ring may be inclined to match the incline of inclined surface 22 as illustrated in FIG. 3. This prevents the edge of the split ring from digging into the inclined surface. By providing the recesses 18 and 20 on the lateral surfaces of the cap 12 and base 10, the split ring 24 also serves as a locking device to hold the cap 12 and base 10 together. During assembly, the split ring 24 is placed in recess 18. As the cap 12 is inserted into base 10, the split ring 24 is compressed until the recesses 18 and 20 are aligned, at which point, the split ring expands into recess 20 of the base 10 and locks the cap 12 and base 10 together.
From the preceding description of the preferred embodiment, it is evident that the objects of the invention are attained in that a non-slip turning joint for a fuze is provided. It should be understood that I do not desire it to be limited to the exact detailed construction shown and described, for obvious modifications can be made by persons skilled in the art. | Relative rotation of the two rotational members of a fuze during dynamic dition of firing are eliminated by interlocking annular, serrated, axial seating surfaces of the two members. A radially sinusoidal split ring in between radially adjacent annular recesses of the members cooperates with an inclined wall of the outer member's annular recess to provide an axial force biasing the serrated surfaces into engagement during static conditions. The split ring further serves as a locking device to hold the two members together as an assembly. | 8 |
TECHNICAL FIELD
[0001] The present invention relates to a system for avoiding collision which is configured to avoid collision with a plurality of moving bodies and obstacles around a local vehicle, and particularly to a system for avoiding collision which is configured to, in a right/left turning scene at an intersection where a movement path of the local vehicle intersects with movement paths of the plurality of moving bodies, avoid collision with another moving body crossing a road after the local vehicle makes a right/left turn while avoiding collision with a moving body traveling in an oncoming direction of the local vehicle.
BACKGROUND ART
[0002] Conventionally, a collision avoidance or a collision reduction brake system has been applied to vehicles. There is a technique of detecting an obstacle around a local vehicle to avoid collision with the obstacle in advance. For example, in the collision avoidance brake system, the brake of the local vehicle is automatically controlled on the basis of a relative distance and a relative speed between the local vehicle and the obstacle around the local vehicle to avoid the collision with the obstacle.
[0003] Herein, in a case where the local vehicle crosses a movement path of another moving body so as to make a right turn at the intersection, and when there is a crossing pedestrian after the local vehicle crosses the oncoming vehicle lane, the local vehicle remains in the oncoming vehicle lane for the operation of the collision avoidance control with respect to the crossing pedestrian. Therefore, there is a possibility to hinder the travel of the oncoming vehicle which travels on the oncoming vehicle lane. There is disclosed in PTL 1 an example of a control device for realizing both the avoidance of the travel hindrance with respect to the oncoming vehicle on the oncoming vehicle lane and the collision avoidance with respect to the crossing pedestrian after crossing the oncoming vehicle lane.
[0004] In PTL 1, the travel hindrance and collision with respect to the oncoming vehicle is avoided while avoiding the collision with the obstacle after crossing the oncoming vehicle lane. Therefore, when the local vehicle crosses the oncoming vehicle lane, an area of the oncoming vehicle lane is estimated. The obstacle after crossing the oncoming vehicle lane is detected. A request deceleration necessary for avoiding the collision with the detected obstacle is calculated. A stop position of the local vehicle is estimated on the basis of the calculated request deceleration. It is determined whether the local vehicle is to be stopped in the area of the oncoming vehicle lane on the basis of the estimated stop position of the local vehicle and the estimated area of the oncoming vehicle lane. In a case where it is determined that the local vehicle is stopped in the area of the oncoming vehicle lane, the request deceleration of the local vehicle is corrected. In other words, in a case where the local vehicle is estimated to be stopped in the oncoming vehicle lane due to the request deceleration of the local vehicle performed to avoid the collision with the obstacle after the local vehicle crosses the oncoming vehicle lane, the request deceleration of the local vehicle for the collision avoidance is corrected. Therefore, the stopping of the local vehicle in the oncoming vehicle lane and the collision with the obstacle after crossing the oncoming vehicle lane both are avoided.
CITATION LIST
Patent Literature
[0005] PTL 1: JP 2012-56347 A
SUMMARY OF INVENTION
Technical Problem
[0006] In the content disclosed in PTL 1, in a case where the local vehicle is estimated to be stopped in the oncoming vehicle lane by the request deceleration of the local vehicle for the collision avoidance with respect to the obstacle after the local vehicle crosses the oncoming vehicle lane, the request deceleration of the local vehicle for the collision avoidance is corrected. However, in such a conventional collision avoidance device (system), in a case where there is an obstacle after crossing the oncoming vehicle at a position too close to the oncoming vehicle lane, and more specifically, in a case where there is a moving body after crossing the oncoming vehicle lane at a position in a distance shorter than the entire length of the local vehicle from the end of the road on the oncoming vehicle lane, even when the deceleration for the collision avoidance of the local vehicle with respect to the obstacle after the crossing the oncoming vehicle lane is changed, the local vehicle performs the collision avoidance after crossing the oncoming vehicle lane and thus stops ahead of the obstacle. In this case, the local vehicle inevitably stops in an area of the oncoming vehicle lane. In this way, the local vehicle necessarily stops to avoid the collision with the moving body after crossing the oncoming vehicle lane depending on a positional relation to the obstacle after crossing the oncoming vehicle lane. Therefore, there may be a difficulty for the local vehicle to stop or to stop in the area of the oncoming vehicle lane.
[0007] Regarding such a problem, the invention is made to provide a system for avoiding the collision, when the local vehicle crosses the oncoming vehicle lane, to avoid collision with a plurality of moving bodies, in which the collision with a moving body which is present after crossing the oncoming vehicle lane is avoided while avoiding the collision or not hindering the moving body from traveling on the oncoming vehicle lane which may occur when the local vehicle stops in the oncoming vehicle lane.
Solution to Problem
[0008] A system for avoiding collision with a plurality of moving bodies according to the invention detects, with respect to at least two or more moving bodies in an advancing direction on a path of a local vehicle, an external environment before the local vehicle intersects with a path of a first moving body firstly intersecting with the path of the local vehicle. In a case where at least two moving bodies, that is, the first moving body and a second moving body having a path in which a position intersecting with the travel path of the local vehicle is farther than a position where the path of the first moving body intersects with a path of the second moving body are detected, a first intersection time at which the first moving body arrives at a first intersection position where a planned path of the local vehicle intersects with a predicted path of the first moving body, and a second intersection time at which the second moving body arrives at a second intersection position where the planned path of the local vehicle intersects with the predicted path of the second moving body are calculated. Braking control with respect to the first moving body and the second moving body is changed according to a difference between the second intersection time and the first intersection time.
[0009] More specifically, when the second intersection time is equal to or more than a predetermined margin time by the first intersection time, the local vehicle is increased in deceleration ahead of a first intersection position, or stopped ahead of the first intersection position. Furthermore, a system for avoiding collision with a plurality of moving bodies according to the invention detects, when an intention of a right turn with respect to an intersection in front of the local vehicle is detected, a moving body traveling on an oncoming vehicle lane and a moving body crossing a road after making a right turn. A first intersection time when the moving body in the oncoming vehicle lane having a possibility to intersect with a right path of the local vehicle arrives at an intersection position where the moving body intersects with the right turn path of the subject body, and a second intersection time when the moving body crossing after making a right turn having a possibility to intersect with the right turn path of the local vehicle arrives at an intersection position where the moving body intersects with the right turn path of the local vehicle are output. Braking control with respect to the moving body in the oncoming vehicle lane and the moving body crossing after making a right turn is changed according to a difference between the first intersection time and the second intersection time.
Advantageous Effects of Invention
[0010] A system for avoiding collision with a plurality of moving bodies according to the invention detects, with respect to at least two or more moving bodies in an advancing direction on a path of a local vehicle, an external environment before the local vehicle intersects with a path of a first moving body firstly intersecting with the path of the local vehicle. In a case where at least two moving bodies, that is, the first moving body and a second moving body having a path in which a position intersecting with the travel path of the local vehicle is farther than a position where the path of the first moving body intersects with a path of the second moving body are detected, a first intersection time at which the first moving body arrives at a first intersection position where a planned path of the local vehicle intersects with a predicted path of the first moving body, and a second intersection time at which the second moving body arrives at a second intersection position where the planned path of the local vehicle intersects with the predicted path of the second moving body are calculated. Braking control with respect to the first moving body and the second moving body is changed according to a difference between the second intersection time and the first intersection time. More specifically, when the second intersection time is equal to or more than a predetermined margin time by the first intersection time, the local vehicle is increased in deceleration ahead of a first intersection position, or stopped ahead of the first intersection position. Therefore, a change in behavior of the local vehicle is not predicted by performing the collision avoidance on one moving body, but on both the first moving body and the second moving body, so that the both collisions can be effectively avoided.
[0011] Specifically, a system for avoiding collision with a plurality of moving bodies according to the invention detects, when an intention of a right turn with respect to an intersection in front of the local vehicle is detected, a moving body traveling on an oncoming vehicle lane and a moving body crossing a road after making a right turn. A first intersection time when the moving body in the oncoming vehicle lane having a possibility to intersect with a right path of the local vehicle arrives at an intersection position where the moving body intersects with the right turn path of the subject body, and a second intersection time when the moving body crossing after making a right turn having a possibility to intersect with the right turn path of the local vehicle arrives at an intersection position where the moving body intersects with the right turn path of the local vehicle are output. Braking control with respect to the moving body in the oncoming vehicle lane and the moving body crossing after making a right turn is changed according to a difference between the first intersection time and the second intersection time. Therefore, in a case where the local vehicle crosses the oncoming vehicle lane to make a right turn and there is a collision possibility with a crossing pedestrian after making a right turn, the local vehicle is decelerated to avoid the collision with the crossing pedestrian, so that a condition of the collision possibility with the oncoming vehicle on the oncoming vehicle lane can be determined before making a right turn and thus the both collisions can be effectively avoided. Furthermore, in a case where there is a possibility to collide with any one of the oncoming vehicle and the crossing pedestrian when making a right turn, it is determined before making a right turn and an alarm is output. Therefore, the driver can effectively perform the collision avoidance operation.
BRIEF DESCRIPTION OF DRAWINGS
[0012] FIG. 1 is an explanatory diagram illustrating an entire configuration of an embodiment of a vehicle in which a system for avoiding collision with a plurality of moving bodies according to the invention is mounted.
[0013] FIG. 2 is an explanatory diagram illustrating a configuration of an embodiment of a system in which the system for avoiding collision with the plurality of moving bodies according to the invention is realized.
[0014] FIG. 3 is an explanatory diagram illustrating a configuration of an embodiment relating to an external environment detection means according to the invention.
[0015] FIG. 4 is an explanatory diagram illustrating a configuration of another embodiment relating to the external environment detection means according to the invention.
[0016] FIG. 5 is an explanatory diagram illustrating an outline of the external detection at an intersection using the external environment detection means according to the invention.
[0017] FIG. 6 is an explanatory diagram relating to the detection of other moving bodies at an intersection using the external environment detection means according to the invention.
[0018] FIG. 7 is an explanatory diagram relating to an embodiment of various types of information of an intersection which is acquired by a map information acquisition means according to the invention.
[0019] FIG. 8 is an explanatory diagram relating to an embodiment of various types of information of an intersection which is acquired by the map information acquisition means according to the invention.
[0020] FIG. 9 is a flowchart illustrating an embodiment relating to control for avoiding collision on the basis of the external detection in the system for avoiding collision with the plurality of moving bodies according to the invention.
[0021] FIG. 10 is a flowchart illustrating a flowchart of an embodiment relating to a determination on collision with the plurality of moving bodies and control in the system for avoiding collision with the plurality of moving bodies according to the invention.
[0022] FIG. 11 is an explanatory diagram of an embodiment of a travel scene to which the system for avoiding collision with the plurality of moving bodies according to the invention is applied, illustrating respective parameters and a positional relation between a local vehicle, an oncoming vehicle, and a pedestrian who crosses a road after the local vehicle makes a right turn at the intersection.
[0023] FIG. 12 is an explanatory diagram of an embodiment of the travel scene to which the system for avoiding collision with the plurality of moving bodies according to the invention is applied, relating to control and a determination on that the local vehicle makes a right turn to cross an oncoming vehicle lane in a relation between the local vehicle, the oncoming vehicle, and the pedestrian who crosses the road from an oncoming direction of the local vehicle at the intersection.
[0024] FIG. 13 is an explanatory diagram of an embodiment of the travel scene to which the system for avoiding collision with the plurality of moving bodies according to the invention is applied, relating to control and a determination on that the local vehicle does not cross the oncoming vehicle lane but stops before making a right turn in a relation between the local vehicle, the oncoming vehicle, the pedestrian who crosses the road from the oncoming direction of the local vehicle at the intersection.
[0025] FIG. 14 is an explanatory diagram of another embodiment of the travel scene to which the system for avoiding collision with the plurality of moving bodies according to the invention is applied, relating to control and a determination on that the local vehicle makes a right turn to cross the oncoming vehicle lane in a relation between the local vehicle, the oncoming vehicle, and the pedestrian who crosses the road from the oncoming direction of the local vehicle at the intersection.
[0026] FIG. 15 is an explanatory diagram of another embodiment of the travel scene to which the system for avoiding collision with the plurality of moving bodies according to the invention is applied, relating to control and a determination on that the local vehicle does not cross the oncoming vehicle lane but stops before making a right turn in a relation between the local vehicle, the oncoming vehicle, and the pedestrian who crosses the road from the same direction as that of the subject direction at the intersection.
[0027] FIG. 16 is an explanatory diagram of another embodiment of the travel scene to which the system for avoiding collision with the plurality of moving bodies according to the invention is applied, relating to control and a determination on that the local vehicle makes a right turn to cross the oncoming vehicle lane in a relation between the local vehicle, the oncoming vehicle, and the pedestrian who cross the road from the same direction as that of the local vehicle at the intersection.
[0028] FIG. 17 is an explanatory diagram of another embodiment of the travel scene to which the system for avoiding collision with the plurality of moving bodies according to the invention is applied, relating to control and a determination on whether the local vehicle can make a left turn before making a left turn in a relation between the local vehicle, a light vehicle (bicycle) running in the oncoming direction with respect to the local vehicle, the pedestrian who crosses the road after the local vehicle makes a left turn at the intersection.
[0029] FIG. 18 is an explanatory diagram of another embodiment of the travel scene to which the system for avoiding collision with the plurality of moving bodies according to the invention is applied, relating to control and a determination on whether the local vehicle can make a right turn before making a right turn in a relation between the local vehicle, the oncoming vehicles in a plurality of oncoming vehicle lanes, and the pedestrian who crosses the road after the local vehicle makes a right turn at the intersection.
[0030] FIG. 19 is a diagram illustrating determination conditions for realizing collision avoidance between three moving bodies when the local vehicle makes a right turn in a scene to which the system for avoiding collision with the plurality of moving bodies according to the invention is applied.
[0031] FIG. 20 is an explanatory diagram relating to a release means which releases a control command of the collision avoidance in the system for avoiding collision with the plurality of moving bodies according to the invention.
DESCRIPTION OF EMBODIMENTS
[0032] FIG. 1 illustrates an outline of the entire system of a vehicle of an embodiment in which a system for avoiding collision with a plurality of moving bodies according to the invention is mounted.
[0033] In FIG. 1 , a vehicle 100 with the system for avoiding collision mounted therein is illustrated in which the front side is directed on the upper side and the rear side is directed on the lower side. The vehicle 100 is provided with a drive source 10 , a transmission 20 which transmits a drive force of the drive source 10 , and a drive source control device 30 which controls the drive source 10 , all of which are configured to drive the vehicle 100 . Further, while the drive source 10 and the transmission 20 are mounted on the front side to drive tires on the front side in the example of FIG. 1 , the same configuration can be applied even in the case of driving the tires on the rear side or in the case of driving all the four wheels.
[0034] Besides the drive source control device 30 for controlling the drive source 10 and the transmission 20 , the vehicle 100 is mounted with a vehicle control device 60 which performs control on the entire vehicle, a communication device 50 which performs a communication with the outside, and a plurality of control devices such as a braking control device 40 which controls brake devices ( 90 - 1 , 90 - 2 , 90 - 3 , and 90 - 4 ) provided in four-wheel tires of the vehicle 100 . These components are connected to a control network 70 , and communicate with information to each other. In the embodiment of FIG. 1 , the vehicle control device 60 is mounted in the vehicle 100 , and receives external environment information acquired by external environment recognition devices ( 80 - 1 , 80 - 2 , 80 - 3 , and 80 - 4 ) which acquire the external environment information around the vehicle 100 and information of a vehicle status quantity (speed, yaw rate, yaw angle, longitudinal acceleration, lateral acceleration, and steering angle) indicating a status of the vehicle 100 . The vehicle control device controls the vehicle 100 according to the external environment information. The vehicle status quantity indicating the status of the vehicle 100 is detected by a yaw rate sensor, an acceleration sensor, a speed sensor, and a steering sensor, which are not illustrated in FIG. 1 .
[0035] In addition, there is provided a right/left turn determination means 110 which determines whether the vehicle 100 makes a right/left turn. A result on the right/left turn of the vehicle 100 determined by the right/left turn determination means 110 is transmitted to the vehicle control device 60 . The right/left turn determination means 110 may determine a right/left turn of the vehicle on the basis of a result of a driver's operation on a direction indicator of the vehicle 100 , or may automatically determine a right/left turn in advance when the vehicle 100 approaches a position for the right/left turn in a travel route on the basis of the travel route where the vehicle 100 travels, a determination result on a position of the vehicle 100 , and map information of the travel route.
[0036] The communication device 50 is a device for transferring the communication from the outside and acquires, for example, road information (an intersection, a road width, the number of lanes, and a curve radius) in the vicinity of the travel route during traveling. Alternatively, the communication device may acquire position information of another vehicle and position information of a pedestrian in the vicinity of the travel route during traveling.
[0037] The external environment recognition device 80 ( 80 - 1 , 80 - 2 , 80 - 3 , and 80 - 4 ) is a device for acquiring information on the external environment around the vehicle 100 (as a specific example, image information and image recognition using a camera). For the image information using the camera, there are used a monocular camera (a single camera) for recognizing the external environment and a stereo camera (two cameras) for recognizing the external environment. In the image information and the image recognition using the camera, the plurality of moving bodies (a vehicle, a pedestrian, and a light vehicle (bicycle)) around the vehicle 100 can be simultaneously recognized as the external information of the vehicle 100 , and characteristics of the moving bodies can be classified. In addition, it is possible to detect a relative distance to the moving body or an obstacle around the vehicle 100 by using the stereo camera.
[0038] An alarm device 120 and a display device 130 inform a situation to a driver by presenting information such as a sound or a video in a case where there is a risk to a moving body or an obstacle around the vehicle on the basis of the external environment information obtained by the external environment recognition device 80 and the communication device 50 , and the vehicle status quantity (speed, yaw rate, yaw angle, longitudinal acceleration, lateral acceleration, and steering angle) indicating a status of the vehicle 100 . Alternatively, in a case where there is a risk of collision, the fact of that risk is informed to the driver when the vehicle control device 60 automatically performs control of steering and braking of the vehicle 100 before the driver performs an operation.
[0039] FIG. 2 illustrates an embodiment for describing a part of the configuration of the vehicle control device 60 . In the embodiment of FIG. 2 , the vehicle control device 60 is configured by at least a local vehicle position information processing means 61 , a road information processing means 62 , an external environment information processing means 63 , a local vehicle information processing means 64 , a right/left turn determination processing means 65 , a collision avoidance control means 66 , a braking control calculation means 67 , a display means 68 , and an alarm means 69 .
[0040] The local vehicle position information processing means 61 performs a process of specifying a position of a local vehicle 100 using a GPS. The position of the local vehicle 100 may be specified from the external environment information acquired by the external environment recognition device 80 in place of the GPS. For example, image data of the surroundings of the local vehicle 100 is acquired by the camera, and collated with an external environment image and position information stored so as to specify the position of the local vehicle 100 . Alternatively, there is a method of recognizing a specific land mark in the image to specify the position of the local vehicle 100 from relative position information of the local vehicle with respect to the land mark and absolute position information of the land mark.
[0041] A road information processing means 62 acquires information on a planned travel of the local vehicle 100 from the road information around the local vehicle 100 or the map information. For example, as an embodiment of the invention, in a case where the local vehicle 100 performs a right/left turn operation at a certain intersection, there is acquired the information on the intersection where the local vehicle 100 makes a right/left turn. Examples of intersection/road information include the number of lanes of the road at the intersection, the road width, a crossing angle of the road, the number of lanes, a median width, a crosswalk width, a setback distance of the crosswalk from the intersection, and the presence/absence of a traffic signal. Such road information may be stored as one of the map information, or may be acquired as map/road information data through the communication device 50 . In particular, in a case where the map/road information data is acquired from a data center through the communication device 50 , the up-to-date map/road information can be effectively acquired. In addition, the road information may be acquired from, for example, the image information acquired by the external environment recognition device 80 . In addition, the acquired map/road information data is utilized for specifying the position of the local vehicle 100 in the local vehicle position information processing means 61 .
[0042] The external environment information processing means 63 obtains the road information around the local vehicle 100 , traffic signal/sign information, position information of an obstacle, and position/speed information of a moving body from the external environment information of the surrounding environment acquired by the external environment recognition device 80 mounted in the local vehicle 100 . In the external environment recognition device 80 , there is employed a method of using the image data of the camera, or a method of using a laser radar or a millimeter wave radar. In a case where the image data of the camera is used, the information can be acquired by identifying the types of obstacles and moving bodies at the same time. In particular, in the case of the stereo camera using two cameras, a relative distance and a relative speed between the moving body and the obstacle can be detected and thus is advantageous.
[0043] The local vehicle information processing means 64 acquires a quantity of the operation status of the local vehicle 100 . As specific examples, there are a speed, a longitudinal acceleration, a lateral acceleration, a yaw rate, a yaw angle, and a steering angle of the local vehicle 100 .
[0044] The right/left turn determination processing 65 determines an intention of a right/left turn of the local vehicle 100 . Specifically, it is determined whether the driver will change the local vehicle 100 to a right turn, a left turn, or another lane in front thereof on the basis of a driver's operation on a blinker (the direction indicator). In addition, in a case where a planned travel route is set by a navigation apparatus, it is also possible to determine whether the local vehicle 100 is in a situation of a right/left turn on the basis of the travel route and the position of the local vehicle 100 on the map.
[0045] The collision avoidance control means 66 determines whether there is a possibility to cause a collision with a moving body or an obstacle around the local vehicle 100 in the travel state of the local vehicle 100 using the result processed in the local vehicle position information processing means 61 , the road information processing means 62 , the external environment information processing means 63 , the local vehicle information processing means 64 , and the right/left turn determination processing means 65 . In a case where there is a possibility of collision, the collision avoidance control means calculates a control command for avoiding the collision. In addition, an alarm is output to the driver before control such as the collision avoidance is performed. The control command calculated by the collision avoidance control means 66 is sent to the operation amount calculation means 67 . In the operation amount calculation means 67 , an operation amount of the brake device 40 for the collision avoidance of the local vehicle 100 , or an operation amount of a steering device is calculated on the basis of the control command, and output. In addition, an alarm signal is output to a warning means and the display means 68 in order to call a driver's attention. Alternatively, a control content calculated for the collision avoidance is informed in advance as an alarm. Since a content of an avoidance operation and a warning are displayed for the driver, the driver is able to be effectively prompted for an appropriate preparation before the collision avoidance control means 66 performs a command for the collision avoidance.
[0046] FIG. 3 is an embodiment relating to a processing block of the collision avoidance control means 66 illustrated in FIG. 2 .
[0047] When making a right/left turn at the intersection, the collision avoidance control means 66 determines a possibility of collision from the positions and the speeds of at least two or more moving bodies and obstacles around the local vehicle 100 . In a case where there is a possibility of collision, control for the avoidance is performed. The collision avoidance control means 66 of FIG. 3 in the embodiment is configured by at least moving body detection data 601 , road information acquisition data 602 , local vehicle status detection data 603 , a first intersection time estimation means 604 , a second intersection time estimation means 605 , a first arrival time estimation means 606 , a second arrival time estimation means 607 , a predicted time comparison means 608 , a collision determination means 609 , and a control select means 610 .
[0048] The moving body detection data 601 is data obtained by calculating the positions and the speeds of the plurality of moving bodies and obstacles around the local vehicle 100 from the external environment information processing means 63 and the local vehicle position information means 61 on the basis of the external environment information obtained by the external environment recognition device 80 . As the moving body, there are a vehicle such as an automobile, a truck, a two-wheeled vehicle, and a light vehicle (bicycle), and a pedestrian. In particular, the moving bodies and the obstacles which intersect with the travel path of the local vehicle 100 and have a possibility of collision are prioritized as high as the position intersecting with the travel path of the local vehicle 100 closes to the current position of the local vehicle 100 .
[0049] The road information acquisition data 602 is data of the road/intersection information calculated by the road information processing means 62 from the information on the road at the intersection around the local vehicle 100 obtained by the communication device 50 and the external environment recognition device 80 . Specifically, as the road information acquisition data, there are the number of lanes of the road, the road width, the lane width, the crossing angle of the intersection, the crosswalk width, and an offset (setback) amount of the crosswalk.
[0050] The local vehicle status detection data 603 is data indicating a status of the local vehicle 100 calculated by the local vehicle information processing means 64 from the data acquired from various types of sensors mounted in the local vehicle 100 . Specifically, as the local vehicle status detection data, there are the speed, the yaw rate, the yaw angle, the longitudinal/lateral acceleration, and the steering angle of the local vehicle 100 .
[0051] The first intersection time estimation means 604 acquires speed and position data of a moving body (hereinafter, referred to as a first moving body) around the local vehicle 100 , of which the position intersecting with the travel path of the local vehicle 100 is closest to the current position of the local vehicle 100 on the basis of the moving body detection data 601 , among the plurality of moving bodies having a possibility of collision with the travel path of the local vehicle 100 . Further, the travel path of the local vehicle 100 may be generated from road/intersection data obtained by the road information acquisition data 602 . For example, considering a case of making a right turn at the intersection, the local vehicle acquires the road/intersection data before entering the intersection. Assuming the oncoming vehicle as the moving body, the local vehicle 100 comes to travel on the path intersecting with the oncoming vehicle. The intersecting position at that time is on the oncoming vehicle lane in the intersection where the oncoming vehicle travels. More specifically, the path on which the local vehicle 100 makes a right turn at the intersection can be predicted and estimated from intersection data (such as a traveling speed of the local vehicle 100 at the intersection, the crossing angle of the intersection, and the number of lanes of the intersection) and a travel path on which the local vehicle 100 can travel while smoothly changing the steering angle at a lateral acceleration equal to or less than a predetermined value. Using the speed and the position data of the first moving body and data indicating a position (hereinafter, referred to as a first intersection position) at which the first moving body intersects with the travel path of the local vehicle 100 , the first intersection time estimation means 604 estimates a time (hereinafter, referred to as a first intersection time) when the first moving body arrives at the first intersection position. As a method of estimating the first intersection time, there is a method of estimating the first intersection time from the current speed of the first moving body and a distance between the position of the first moving body and the first intersection position as follows.
[0000] TCP 1= L 1/ V 1 [Expression 1]
[0052] Herein, TCP 1 : the first intersection time [s] when the first moving body arrives at the first intersection position,
[0053] L 1 : a distance [m] between the current position of the first moving body and the first intersection position, and
[0054] V 1 : the current speed [m/s] of the first moving body.
[0055] The second intersection time estimation means 605 acquires the speed and the position data of a moving body (hereinafter, referred to as a second moving body) around the local vehicle 100 , of which the position intersecting with the travel path of the local vehicle 100 is near in the second place to the current position of the local vehicle 100 among a plurality of moving bodies having a possibility to intersect with the travel path of the local vehicle 100 on the basis of the moving body detection data 601 . For example, assuming that the first moving body is the oncoming vehicle and the second moving body is the pedestrian who crosses the road after the local vehicle 100 makes a right turn, in a case where the local vehicle makes a right turn at the intersection, the local vehicle 100 comes to travel on the path intersecting with both the oncoming vehicle and the pedestrian. The position at this time intersecting with the second moving body comes to be on the road where the pedestrian moves after the local vehicle makes a right turn. Herein, in a case where there is a crosswalk, the intersection position comes to be on the crosswalk. In this way, using the speed and the position data of the second moving body and the data indicating a position (hereinafter, referred to as a second intersection position) where the second moving body intersects with the travel path of the local vehicle 100 , the second intersection time estimation means 605 estimates the time (hereinafter, referred to as a second intersection time) when the second moving body arrives at the second intersection position. As a method of estimating the second intersection time, there is a method of obtaining the second intersection time from the current speed of the second moving body and a distance between the position of the second moving body and the second intersection position as follows.
[0000] TCP 2= L 2/ V 2 [Expression 2]
[0056] Herein, TCP 2 : the second intersection time [s] when the second moving body arrives at the second intersection position,
[0057] L 2 : a distance [m] between the current position of the second moving body and the second intersection position, and
[0058] V 2 : the current speed of the second moving body [m/s].
[0059] The first arrival time estimation means 606 estimates a time (hereinafter, referred to as a first arrival time) when the local vehicle 100 arrives at the first intersection position from a status quantity of the local vehicle 100 calculated by the local vehicle status detection data 603 . As a method of estimating the first arrival time, there is a method of obtaining the first arrival time from the current speed of the local vehicle 100 and a distance between the position of the local vehicle 100 and the first intersection position as follows.
[0000] TTP 1= LO 1/ V 0 [Expression 3]
[0060] Herein, TTP 1 : the first arrival time [s],
[0061] LO 1 : a distance [m] between the current position of the local vehicle and the first intersection position, and
[0062] V 0 : the current speed [m/s] of the local vehicle.
[0063] The second arrival time estimation means 607 estimates a time (hereinafter, referred to as a second arrival time) when the local vehicle 100 arrives at the second intersection position from the status quantity of the local vehicle 100 calculated by the local vehicle status detection data 603 . As a method of estimating the second arrival time, there is a method of obtaining the second arrival time from the current speed of the local vehicle 100 and a distance between the position of the local vehicle 100 and the second intersection position.
[0000] TTP 2= LO 2/ V 0 [Expression 4]
[0064] Herein, TTP 2 : the second arrival time [s],
[0065] LO 2 : a distance [m] between the current position of the local vehicle and the second intersection position, and
[0066] V 0 : the current speed [m/s] of the local vehicle.
[0067] The predicted time comparison means 608 compares the first intersection time obtained by the first intersection time estimation means 604 with the second intersection time obtained by the second intersection time estimation means 605 , determines a control method for the first moving body and the second moving body, and outputs a determination result to the control select means 610 .
[0068] The collision determination means 609 performs a collision possibility determination on the first moving body and the local vehicle 100 from the first intersection time calculated by the first intersection time estimation means 604 and the first arrival time calculated by the first arrival time estimation means 606 , and a collision possibility determination on the second moving body and the local vehicle 100 from the second intersection time calculated by the second intersection time estimation means 605 and the second arrival time calculated by the second arrival time estimation means 607 , and then outputs the determination results to the control select means 610 .
[0069] The control select means 610 selects an avoidance control method of the local vehicle 100 on the basis of the comparison result of the predicted time comparison means 608 , the collision possibility determination result on the first moving body and the local vehicle 100 determined by the collision determination means 609 , and the collision possibility determination result on the second moving body and the local vehicle 100 determined by the collision determination means 609 . Herein, the control select means 610 includes a plurality of kinds of control, for example, controls of a first control means 611 which does not perform the collision avoidance control, a second control means 612 which performs the avoidance control on the oncoming vehicle, a third control means 613 which performs the avoidance control on the crossing pedestrian, a fourth control means which does not perform a right turn operation, and a release means 615 which releases the avoidance control selected from the first control means 611 to the fourth control means 614 in a case where there is a driver's operation on the local vehicle 100 on the basis of the local vehicle status detection data 603 . Selected control is performed. The control method selected by the control select means 610 is output from the collision avoidance control means 66 . Based on the control method, the operation amount calculation means 67 calculates an operation command of the avoidance control and performs the avoidance control.
[0070] While the control select means 610 has been described to select the plurality of kinds of controls in the above, an alarm may be output to the driver on the basis of a collision possibility with another moving body. For example, as a specific embodiment, the control select means includes a plurality of kinds of control of the first control means 611 which determines that there is no collision possibility and does not issue an alarm to the driver, the second control means 612 which determines that there is a collision possibility with the oncoming vehicle and issues an alarm on the collision possibility with the oncoming vehicle, the third control means 613 which determines that there is a collision possibility with the crossing pedestrian and issues an alarm on the collision possibility with the crossing pedestrian, the fourth control means which stops the local vehicle 100 because of the crossing pedestrian when making a right turn, determines that there is a collision possibility with the oncoming vehicle, and issues an alarm on the right turn operation, and the release means 615 which releases an alarm selected from the first control means 611 to the fourth control means 614 in a case where there is a driver's operation on the local vehicle 100 on the basis of the local vehicle status detection data 603 . Selected control is performed. A content of the alarm selected by the control select means 610 is output from the collision avoidance control means 66 . Based on the content, the alarm means 69 outputs an alarm to the driver.
[0071] While the control select means 610 has been described to select the plurality of kinds of control or the plurality of alarms in the above, an alarm may be selected at the same time with the selection of control, and the alarming to the driver may be performed at the same time with the collision avoidance control. Alternatively, the collision avoidance control may be performed after the alarming to the driver is performed.
[0072] FIG. 4 illustrates an external environment recognition area of the external environment recognition device 80 mounted in the local vehicle 100 . In particular, FIG. 4 is an embodiment of a case where a camera is used as the external environment recognition device 80 . Similarly to the embodiment of FIG. 1 , the local vehicle 100 of FIG. 4 may use cameras, as the external environment recognition device 80 , in the external environment recognition device 80 - 1 which performs an external environment recognition on the front side of the local vehicle 100 , the external environment recognition device 80 - 2 which performs an external environment recognition on the right side of the local vehicle 100 , the external environment recognition device 80 - 3 which performs an external environment recognition on the left side of the local vehicle 100 , and the external environment recognition device 80 - 4 which performs an external environment recognition on the rear side of the local vehicle 100 . The front side of the local vehicle 100 indicates a side in a direction where the local vehicle 100 advances. A preceding vehicle in front of the local vehicle 100 , the oncoming vehicle, and the crossing pedestrian after making a right/left turn are detected. Therefore, the moving body and the obstacle in an area A illustrated in FIG. 4 are detected in order to recognize the preceding vehicle and the oncoming vehicle at a relatively remote place. Furthermore, the moving body and the obstacle in an area B illustrated in FIG. 4 are detected in order to recognize the crossing pedestrian after making a right/left turn. In this way, the front side of the vehicle is necessarily detected over an area at a wide detection angle from remote to close. Furthermore, the position and the speed of the moving body are necessarily detected with accuracy. In the example of FIG. 4 , as an embodiment to realize this detection, there is mounted the external environment recognition device 80 - 1 in which a short-distance wide angle camera for detecting a relatively close and wide angle distance (the area B) and a long-distance camera for detecting a relatively remote distance are combined. In particular, the stereo camera and a long-distance/short-distance wide angle stereo camera are used in order to detect the distance and the speed with accuracy.
[0073] An area C of FIG. 4 is a relatively close area surrounding the entire local vehicle 100 not in the advancing direction of the local vehicle 100 . Regarding the area C, there are used the external environment recognition device 80 - 1 which performs an external environment recognition on the front side of the local vehicle 100 , the external environment recognition device 80 - 2 which performs an external environment recognition on the right side of the local vehicle 100 , the external environment recognition device 80 - 3 which performs an external environment recognition on the left side of the local vehicle 100 , and the external environment recognition device 80 - 4 which performs an external environment recognition on the rear side of the local vehicle 100 , so that the detection of the entire surroundings is covered.
[0074] FIG. 5 illustrates another embodiment of the external environment recognition areas using the external environment recognition device 80 mounted in the local vehicle 100 . In FIG. 5 , the areas A, B, and C described in the embodiment of FIG. 4 are recognized using the cameras as the external environment recognition device 80 . Furthermore, radar sensors different from the camera of the local vehicle 100 are mounted in the periphery of the vehicle to detect the entire surroundings of the local vehicle 100 using the radars. While the radar is difficult to identify the moving body and the obstacle, the radar can detect the distance and the speed of the moving body and the obstacle with a relatively high accuracy compared to the camera. In the embodiment of FIG. 5 , four radars are mounted in the front, rear, right and left portions of the local vehicle 100 to detect the distance and the speed of the moving body and the obstacle in areas D_FL, D_FR, D_RL, and D_RR. With such a configuration, the sensors are fused to identify the moving body and the obstacle around the vehicle 100 using the cameras, and to detect the distance and the speed using the radars, so that the moving body and the obstacle can be detected with high accuracy. Furthermore, even in a scene where the camera is not usable, the speed and the position of the moving body can be detected using the radar.
[0075] The description will be made using FIG. 6 on that the local vehicle 100 recognizes the moving body and the obstacle in a case where the camera is used as the in-vehicle sensor 80 according to the embodiment illustrated in FIGS. 4 and 5 .
[0076] FIG. 6 is an embodiment in a case where the camera is used as the external environment recognition device 80 as described in FIGS. 4 and 5 , and illustrates a situation in which the local vehicle 100 travels on a road RV and enters the intersection. The local vehicle 100 of FIG. 6 uses the cameras in the external environment recognition device 80 - 1 which performs an external environment recognition on the front side of the local vehicle 100 , the external environment recognition device 80 - 2 which performs an external environment recognition on the right side of the local vehicle 100 , the external environment recognition device 80 - 3 which performs an external environment recognition on the left side of the local vehicle 100 , and the external environment recognition device 80 - 4 which performs an external environment recognition on the rear side of the local vehicle 100 . In an area A illustrated in FIG. 6 , the moving body and the obstacle in a relatively wide place from remote to close in front of the local vehicle 100 are detected. In the example of FIG. 6 , the preceding vehicle and the oncoming vehicle are detected. In addition, in an area B, the moving body and the obstacle in a wide angle place at a relatively close distance from the local vehicle 100 are detected. In the example of FIG. 6 , the pedestrian and the light vehicle (bicycle) crossing a road RH intersecting with the road RV where the local vehicle 100 travels are detected. As long as the external environment information on the front side in a wide angle range can be acquired as illustrated in FIG. 6 , it is possible to detect the moving body and the obstacle on the travel path of the local vehicle 100 or to detect an approaching one when the local vehicle 100 makes a right/left turn. Furthermore, in an area C, the moving body and the obstacle around the local vehicle 100 are detected. In the example of FIG. 6 , the light vehicle (bicycle) and the two-wheeled vehicle on the left side of the local vehicle 100 are detected. Through the detection of the moving body and the obstacle in the vicinity of the local vehicle 100 , the moving body and the obstacle having a possibility to be engaged in the local vehicle 100 when the local vehicle 100 makes a left turn can be detected.
[0077] The description will be made using FIG. 7 about the map/road information relating to an intersection road assumed in the embodiment of the invention. As described in FIGS. 2 and 3 , the intersection/road information is used as the map/road information data in one of the embodiments of the invention. FIG. 8 illustrates the intersection/road information. FIG. 7 illustrates the road in the vicinity of the intersection where two roads (RV, RH) intersect. As the intersection/road information, there are parameters for realizing the shape of the road/intersection necessary for specifying the travel path where the local vehicle 100 travels when the local vehicle 100 makes a right/left turn at the intersection, the position and the area where the vehicle traveling on the oncoming vehicle lane intersects with the travel path of the local vehicle 100 , and the position and the area where the crossing pedestrian intersects with the travel path of the local vehicle 100 after the local vehicle 100 makes a right/left turn. Examples of specific parameters of the embodiment illustrated in FIG. 7 include a central coordinate position of the intersection where the local vehicle 100 intersects with two roads, the crossing angle which is an intersection angle between two roads (RV, RH), a road width 1 , the number 1 -A of lanes on one side, the number 1 -B of lanes on one side, a lane width 1 , a median width 1 , a crosswalk width 1 , a crosswalk setback 1 -A, and a crosswalk setback 1 -B regarding one of the cross roads, and a road width 2 , the number 2 -A of lanes on one side, the number 2 -B of lanes on one side, a lane width 2 , a median width 2 , a crosswalk width 2 , a crosswalk setback 2 -A, and a crosswalk setback 2 -B regarding the other one of the cross roads. When the speed of the local vehicle 100 is determined using these numerical parameters as the intersection/road information, the travel path where the local vehicle 100 travels can be set. Furthermore, when the local vehicle 100 makes a right turn, a position where the vehicle traveling on the oncoming vehicle lane intersects with the local vehicle 100 , and a position where the crossing pedestrian walking on the crosswalk intersects with the local vehicle 100 can be set. A specific example of the intersection/road information described above is illustrated in FIG. 8 .
[0078] FIG. 9 is a diagram of an embodiment illustrating a flow of the entire process relating to the collision avoidance with respect to a plurality of moving bodies according to the invention.
[0079] First, it is determined whether the external environment recognition devices 80 illustrated in FIG. 1 are abnormal (S 20 ). Herein, in a case where there is an abnormality in any one of the external environment recognition devices 80 , it is determined that the external environment recognition device 80 is abnormal, and a collision avoidance process of the invention is not performed. In this case, the alarm device 120 and the display device 130 inform the abnormality to the driver. In a case where there is no abnormality in S 20 , the process proceeds to the next S 30 . In S 30 , it is determined whether the communication device 50 can acquire the road/map information around the local vehicle 100 . In a case where it is not possible to acquire the information due to a communication error, the collision avoidance process of the invention is not performed. In a case where it is determined that there is no abnormality in S 30 , the process proceeds to the next step S 40 . In S 40 , it is determined whether there is an intersection in front of the local vehicle 100 , or whether the local vehicle is in an area where a right/left turn is possible. As a case where it is determined that there is an intersection or the local vehicle is in an area where a right/left turn is possible, there is a case where the external environment recognition device 80 determines that there is an intersection or an area where a right/left turn is possible, and a case where the communication device 50 acquires information of the intersection or the area where a right/left turn is possible. As the information acquired by the communication device 50 , information indicating the presence/absence of the intersection is directly acquired, or information indicating the intersection in front of the local vehicle or the area where a right/left turn is possible may be acquired through matching the position of the local vehicle 100 with the road map information which is acquired. In a case where it is determined that there is the intersection or the area where a right/left turn is possible in front of the local vehicle 100 in S 40 , road intersection information is acquired in S 50 . As the road intersection information, there are the parameters described in FIGS. 7 and 8 . Next, the moving body around the local vehicle is detected by the external environment recognition device 80 (S 60 ). Next, it is determined whether the local vehicle 100 makes a right/left turn on the basis of the intersection in front of the local vehicle 100 and the area where a right/left turn is possible, which are acquired in advance (S 70 ). As the determination on a right/left turn, it is determined whether the driver will make a right turn or a left turn, or change the lane in front of the local vehicle 100 on the basis of a driver's operation on the blinker (the direction indicator) of the local vehicle 100 as described in the embodiment of FIG. 3 . Further, in a case where the travel route is set in advance by a navigation apparatus, it is determined that the local vehicle 100 is in a situation of making a right/left turn from the travel route and the position of the local vehicle 100 on the map. Herein, when it is determined that the local vehicle 100 does not make a right/left turn, the control process of the invention is not performed. On the other hand, when a right/left turn is determined, a possibility of collision with a plurality of moving bodies is determined from the acquired information of the moving bodies and the road/intersection information, and therefore control to be performed is determined (S 80 ). Then, specific control (braking control and steering control) of the collision avoidance is performed on the basis of a control determination of S 80 (S 90 ). Further, in S 90 , besides the specific control for the collision avoidance, the collision possibility with the plurality of moving bodies may be alarmed to the driver on the basis of the control determination of S 80 , and the collision avoidance control and the alarming to the driver may be performed at the same time or the collision avoidance control may be performed after the alarming is performed.
[0080] FIG. 10 is a diagram of an embodiment illustrating a flow of a control determination process related to the collision avoidance with respect to the plurality of moving bodies in S 80 of FIG. 9 . Hereinafter, the description in FIG. 10 will be made about a case where there is the oncoming vehicle on an oncoming vehicle lane of the local vehicle 100 when the local vehicle 100 makes a right turn, and a pedestrian crosses the road after the local vehicle 100 makes a right turn at the intersection.
[0081] In FIG. 10 , the detection of the moving body in S 60 of FIG. 9 is performed in S 801 . As a result, it is determined whether two moving bodies (that is, the oncoming vehicle traveling on the oncoming vehicle lane of the local vehicle 100 and the pedestrian who crosses the road after the local vehicle 100 makes a right turn at the intersection) are detected. Herein, in a case where it is detected that neither the oncoming vehicle nor the crossing pedestrian is detected, a case where only the oncoming vehicle is detected, and a case where only the crossing pedestrian is detected, the two moving bodies are not detected, and thus the process of the invention is not performed. On the other hand, in a case where the two moving bodies (the oncoming vehicle and the crossing pedestrian) are detected, the process proceeds to the next step S 802 .
[0082] In S 802 , the first intersection position between the local vehicle 100 and the oncoming vehicle is set. The first intersection time (TCP 1 ) of the oncoming vehicle is calculated as described in (Expression 1), and the first arrival time (TTP 1 ) of the local vehicle 100 is calculated as described in (Expression 3). In addition, the second intersection position between the local vehicle 100 and the crossing pedestrian is set. The second intersection time (TCP 2 ) of the crossing pedestrian is calculated as described in (Expression 2), and the second arrival time (TTP 2 ) of the local vehicle 100 is calculated as described in (Expression 4).
[0083] Herein, the first intersection position where the travel path of the local vehicle 100 intersects with the oncoming vehicle, the second intersection position where the travel path of the local vehicle 100 intersects with the crossing pedestrian, the speed of the oncoming vehicle and the distance to the first intersection position of the oncoming vehicle, and the speed of the crossing pedestrian and the distance to the second intersection position of the crossing pedestrian will be described using FIG. 11 .
[0084] As illustrated in FIG. 11 , at the time of making a right turn at the intersection, the local vehicle 100 travels on a travel path of the local vehicle depicted by the dotted line while rotating from a position (A) to a position (B) of FIG. 11 . The map information around the intersection is acquired from the communication device 50 . The parameters such as the road width, the crossing angle of the intersection, and the number of lanes can be used. The travel path of the local vehicle 100 in the intersection is set in advance from the speed (V 0 ) of the local vehicle 100 and the size of the intersection. The travel path may be stored as data together with the map data. In addition, the travel path of the local vehicle 100 may be sequentially calculated from the vehicle parameters such as the speed, the steering angle, and the yaw rate of the local vehicle 100 . On the other hand, an oncoming vehicle 200 travels straight on the oncoming vehicle lane toward the local vehicle 100 . In addition, a pedestrian 300 crosses the road after the local vehicle 100 makes a right turn at the intersection, and is assumed to move straight in the current advancing direction. In this case, in FIG. 11 , a point CP 1 becomes the first intersection position where the travel path of the local vehicle 100 intersects with the oncoming vehicle 200 , and a point CP 2 becomes the second intersection position where the travel path of the local vehicle 100 intersects with the crossing pedestrian 300 .
[0085] Herein, the local vehicle 100 can estimate the current position of the local vehicle 100 on the actual road using a method such as a local vehicle position estimation using the GPS or a local vehicle position estimation through matching the external environment recognition device and the map/road information.
[0086] Next, the oncoming vehicle 200 local vehicle and the crossing pedestrian 300 in front of the local vehicle are detected by the external environment recognition device 80 of the local vehicle 100 . At this time, the external environment recognition device 80 mounted in the local vehicle 100 detects a distance (Lv) between the local vehicle 100 and the oncoming vehicle 200 and a detection angle (αv), and a distance (Lp) between the local vehicle 100 and the pedestrian 300 and a detection angle (αp) on a coordinate system depicted by the broken line in FIG. 11 . In addition, when the local vehicle 100 rotates in the intersection, the local vehicle 100 is inclined by the yaw angle (θ) of the local vehicle 100 with respect to the absolute coordinate system of the intersection with the center of the intersection as the origin point. The yaw angle of the vehicle can be calculated by an integration function of a yaw rate sensor mounted in the local vehicle 100 . Specifically, the yaw angle (θ) for passing through the intersection, which is a rotation angle in the vehicle coordinate system with respect to the intersection coordinate system, is calculated from the entrance to the intersection until the local vehicle passes through the intersection, and then be cleared to zero after the local vehicle passes through the intersection. Thus, the yaw angle can be obtained from the detection value of the yaw rate sensor. With the distance, the detection angle, the yaw angle for passing through the intersection, and the position coordinates (xv0, yv0) of the local vehicle 100 in the absolute coordinate system of the intersection, the position coordinates (xv1, yv1) of the oncoming vehicle 200 in the absolute coordinate system of the intersection, and the position coordinates (xp1, yp1) of the pedestrian 300 can be obtained as follows.
[0087] The position coordinates (xv1, yv1) of the oncoming vehicle 200 are as follows.
[0000] xv 1= xv 0+ Lv ·sin(θ+α v ), and
[0000] yv 1= yv 0+ Lv ·cos(θ+α v ). [Expression 5]
[0088] (herein, xv0 and yv0 indicate the position coordinates of the local vehicle)
[0089] The position coordinates (xp1, yp1) of the pedestrian 300 are as follows.
[0000] xp 1= xv 0+ Lp ·sin(θ+α p ), and
[0000] yp 1= yv 0+ Lp ·cos(θ+α p ). [Expression 6]
[0090] (herein, xv0 and yv0 indicate the position coordinates of the local vehicle)
[0091] Through (Expression 5) and (Expression 6), the positions of the oncoming vehicle 200 and the pedestrian 100 in the absolute coordinate system of the intersection can be obtained, and the coordinates of the first intersection position and the second intersection position in the absolute coordinate system of the intersection can be obtained. Therefore, the distance between the oncoming vehicle 200 and the first intersection position and the distance between the pedestrian 300 and the second intersection position can be obtained. In addition, when the positions of the oncoming vehicle 200 and the pedestrian 300 are obtained, the speeds of the oncoming vehicle 200 and the pedestrian 300 can also be obtained from an amount of change thereof.
[0092] The description is return to the process flow of FIG. 10 . When the first intersection time, the first arrival time, the second intersection time, and the second arrival time are calculated in S 802 , the process proceeds to S 803 to determine a collision possibility between the local vehicle 100 and the oncoming vehicle 200 . Herein, the collision possibility between the local vehicle 100 and the oncoming vehicle 200 is determined using the first intersection time and the first arrival time. Specifically, for example, in a case where the above Expressions 7 and 8 are established, it is determined that there is no collision possibility.
[0000] TTP 1< TCP 1 −Tcsf [Expression 7]
[0093] TCP 1 : a time (the first intersection time) [s] when the oncoming vehicle 200 arrives at the first intersection position,
[0094] TTP 1 : a time (the first arrival time) [s] when the local vehicle 100 arrives at the first intersection position, and
[0095] Tcsf: a margin time [s].
[0000] TTP 1> TCP 1 +Tcsb [Expression 8]
[0096] TCP 1 : a time (the first intersection time) [s] when the oncoming vehicle 200 arrives at the first intersection position,
[0097] TTP 1 : a time (the first arrival time) [s] when the local vehicle 100 arrives at the first intersection position, and
[0098] Tcsb: a margin time [s].
[0099] Herein, as a condition for satisfying Expression 7, there is a case where the local vehicle 100 arrives at the first intersection position earlier by the margin time Tcsf before the oncoming vehicle 200 arrives at the first intersection position. As a condition for satisfying Expression 8, there is a case where the local vehicle 100 arrives at the first intersection position later by the margin time Tcsb after the oncoming vehicle 200 arrives at the first intersection position. The margin time Tcsf is set to a time at which the driver of the oncoming vehicle 200 feels safe when the local vehicle 100 crosses before the oncoming vehicle 200 . Specifically, the margin time Tcsf is set to, for example, 1.5 to 2.0 seconds. In addition, the time Tcsb is set to a time at which the driver of the local vehicle 100 feels safe when the local vehicle 100 crosses after the oncoming vehicle 200 passes through the road. Specifically, the margin time Tcsb is set to, for example, 1.0 to 1.5 seconds.
[0100] In S 803 , when it is determined that there is a collision possibility with the oncoming vehicle 200 , the process proceeds to S 806 . The collision avoidance control with respect to the oncoming vehicle 200 is selected. Alternatively, an alarm on a collision possibility with the oncoming vehicle 200 is issued.
[0101] In S 803 , when it is determined that there is no collision possibility with the oncoming vehicle 200 , the process proceeds to S 804 .
[0102] In S 804 , it is determined whether there is a collision possibility between the local vehicle 100 and the crossing pedestrian 300 . The collision possibility between the local vehicle 100 and the pedestrian 300 is determined using the second intersection time and the second arrival time. Specifically, for example, in a case where the following Expressions 9 and 10 are satisfied, it is determined that there is no collision possibility.
[0000] TTP 2< TCP 2 −Tpsf [Expression 9]
[0103] TCP 2 : a time (the second intersection time) [s] when the pedestrian 300 arrives at the second intersection position,
[0104] TTP 2 : a time (the second arrival time) [s] when the local vehicle 100 arrives at the second intersection position, and
[0105] Tpsf: a margin time [s].
[0000] TTP 2> TCP 2 +Tpsb [Expression 10]
[0106] TCP 2 : a time (the second intersection time) [s] when the pedestrian 300 arrives at the second intersection position,
[0107] TTP 2 : a time (the second arrival time) [s] when the local vehicle 100 arrives at the second intersection position, and
[0108] Tpsb: a margin time [s].
[0109] Herein, as a condition for satisfying Expression 9, there is a case where the local vehicle 100 arrives at the second intersection position earlier by the margin time Tpsf before the pedestrian 300 arrives at the second intersection position. As a condition for satisfying Expression 10, there is a case where the local vehicle 100 arrives at the second intersection position later by the margin time Tpbf after the pedestrian 300 arrives at the second intersection position. The margin time Tpsf is set to a time at which the pedestrian 300 feels safe when the local vehicle 100 crosses before the pedestrian 300 . Specifically, the margin time Tpsf is set to, for example, 1.5 to 2.0 seconds. In addition, the time Tpsb is set to a time at which the pedestrian 300 and the driver of the local vehicle 100 feel safe when the local vehicle 100 crosses after the pedestrian 300 passes through the road. Specifically, the margin time Tpsb is set to, for example, 1.0 to 1.5 seconds.
[0110] In S 804 , when it is determined that there is no collision possibility with the pedestrian 300 , it is determined that there is no collision possibility with both the oncoming vehicle 200 and the pedestrian 300 . Therefore, the collision avoidance control is not performed. Alternatively, since there is no collision possibility, the alarm is not issued. On the other hand, when it is determined that there is a collision possibility with the pedestrian, the process proceeds to S 805 .
[0111] In S 805 , the first intersection time (TCP 1 ) when the oncoming vehicle 200 arrives at the first intersection position is compared to the second intersection time (TCP 2 ) when the pedestrian 300 arrives at the second intersection position. Through the comparison, it is determined whether a difference between the first intersection time (TCP 1 ) and the second intersection time (TCP 2 ) is smaller than a predetermined value. In a case where the difference between the first intersection time (TCP 1 ) and the second intersection time (TCP 2 ) is larger than the predetermined value, the process proceeds to S 807 to select the collision avoidance control with respect to the crossing pedestrian 300 . In a case where the difference between the first intersection time (TCP 1 ) and the second intersection time (TCP 2 ) is smaller than the predetermined value, the process proceeds to S 808 to select control such as the local vehicle 100 is stopped before making a right turn or decelerated before making a right turn, or an alarm on a collision possibility when making a right turn is issued to the driver.
[0112] The determination using the difference between the first intersection time (TCP 1 ) and the second intersection time (TCP 2 ) will be described in more detail using FIG. 12 .
[0113] FIG. 12 illustrates a positional relation between the local vehicle 100 traveling on the road (RV), the oncoming vehicle 200 traveling on the oncoming vehicle lane of the local vehicle 100 on the road (RV), and the pedestrian 300 crossing the road (RH) intersecting with the road (RV). It is assumed that the local vehicle 100 travels at a speed V 0 at a position (A) before entering the intersection, the oncoming vehicle 200 travels at a speed V 1 at a position (C) on the oncoming vehicle lane, and the pedestrian 300 walks at a speed V 2 at a position (E) before the crosswalk. In addition, the first intersection position where the travel path of the local vehicle 100 intersects with the oncoming vehicle 200 is set to CP 1 . The second intersection position where the travel path of the local vehicle 100 intersects with the pedestrian 300 is set to CP 2 . When a distance between the oncoming vehicle 200 at a position (C) and the first intersection position CP 1 is set to L 1 , and a distance between the pedestrian 300 at a position (E) and the second intersection position CP 2 is set to L 2 , the first intersection time TCP 1 becomes L 1 /V 1 , and the second intersection time TCP 2 becomes L 2 /V 2 .
[0114] In FIG. 12 , (D) indicates the position of the oncoming vehicle 200 when the local vehicle 100 crosses before the oncoming vehicle 200 . Herein, when the local vehicle 100 crosses immediately before the oncoming vehicle 200 , it comes to hinder a course of the oncoming vehicle 200 , and gives fear to the driver of the oncoming vehicle 200 . Therefore, in a case where the local vehicle 100 passes through the first intersection position, it is desirable that the oncoming vehicle 200 be at a position sufficiently away from the first intersection position. The sufficient position depends on the speed of the oncoming vehicle 200 . Therefore, the margin time (Tcsf) is set such that the position is changed according to the speed of the oncoming vehicle 200 . In other words, in a case where the first arrival time (TTP 1 ) of the local vehicle 100 is smaller than a time obtained by subtracting the margin time (Tcsf) from the first intersection time (TCP 1 ), the oncoming vehicle 200 is at a position ahead of the first intersection position by the margin time (Tcsf). Therefore, the local vehicle 100 can cross the oncoming vehicle lane without hindering the course of the oncoming vehicle 200 and without giving fear to the driver. In addition, in FIG. 12 , (H) indicates the position of the oncoming vehicle 200 when the local vehicle 100 crosses the oncoming vehicle lane after the oncoming vehicle 200 passes through the first intersection position (CP 1 ). Herein, when the local vehicle 100 crosses the oncoming vehicle lane immediately after the oncoming vehicle 200 passes through the first intersection position, it is not desirable due to fear for contact. In a case where the local vehicle 100 passes through the first intersection position, it is desirable that the oncoming vehicle 200 pass through up to a sufficient position from the first intersection position. The sufficient position depends on the speed of the oncoming vehicle 200 . Therefore, the margin time (Tcsb) is set such that the position is changed according to the speed of the oncoming vehicle 200 . In other words, in a case where the first arrival time (TTP 1 ) of the local vehicle 100 is larger than a time obtained by adding the margin time (Tcsb) to the first intersection time (TCP 1 ), the oncoming vehicle 200 passes through the first intersection position by the margin time (Tcsb). Therefore, the local vehicle 100 can cross the oncoming vehicle lane while keeping a sufficient distance to the oncoming vehicle 200 .
[0115] Similarly, in FIG. 12 , (F) indicates the position of the pedestrian 200 when the local vehicle 100 crosses the crosswalk after the pedestrian 300 passes through the second intersection position (CP 2 ). Herein, when the local vehicle 100 crosses the crosswalk immediately after the pedestrian 300 passes through the second intersection position, it is not desirable due to giving fear to the pedestrian. Therefore, in a case where the local vehicle 100 passes through the second intersection position, it is desirable that the pedestrian 200 pass through up to a sufficient position from the second intersection position. The sufficient position depends on the speed of the pedestrian 300 . Therefore, the margin time (Tpsb) is set such that the position is changed according to the speed of the pedestrian 300 . In other words, in a case where the second arrival time (TTP 2 ) of the local vehicle 100 is larger than a time obtained by adding the margin time (Tpsb) to the second intersection time (TCP 2 ), the pedestrian 300 passes through the second intersection position by the margin time (Tpsb). Therefore, the local vehicle 100 can cross the crosswalk while keeping a sufficient distance to the pedestrian 300 .
[0116] From the above description, as a condition for the local vehicle 100 to pass through the intersection while avoiding the collision with the oncoming vehicle 200 and the pedestrian 300 and without giving fear to the oncoming vehicle 200 and the pedestrian 300 , the local vehicle passes through the first intersection position (CP 1 ) earlier by a time obtained by subtracting the margin time (Tcsf) from the first intersection time (TCP 1 ), and arrives at the second intersection position (CP 2 ) later by a time obtained by adding the margin time (Tpsb) to the second intersection time (TCP 2 ).
[0117] Herein, the following Expression is defined.
[0000] TTP 1+Δ Tv=TTP 2 [Expression 11]
[0118] Then, the above condition becomes as follows.
[0000] TCP 1 −Tcsf>TTP 1, and
[0000] TCP 2 +Tpsb<TTP 2. [Expression 12]
[0119] Therefore, the following Expression is obtained from [Expression 11] and [Expression 12].
[0000] TCP 1> TTP 1 +Tcsf , and
[0000] TCP 2< TTP 1+Δ Tv−Tpsb. [Expression 13]
[0120] To sum up, the following Expression is obtained.
[0000] TCP 2−Δ Tv+Tpsb<TTP 1, and
[0000] TTP 1< TCP 1 −Tcsf. [Expression 14]
[0121] Therefore, the following Expression is obtained.
[0000] TCP 1− TCP 2 >Tpsb+Tcsf−ΔTv [Expression 15]
[0122] Herein, for example, as illustrated in FIG. 12 , using a relative distance W 12 between the oncoming vehicle 200 and the pedestrian 300 and the speed V 0 of the local vehicle 100 , ΔTv is set to W 12 /V 0 as a time for traveling the relative distance W 12 .
[0123] Further, as another condition other than the above, the local vehicle passes through the first intersection position (CP 1 ) after a time obtained by adding the margin time (Tcsb) to the first intersection time (TCP 1 ), that is, making a right turn after the oncoming vehicle 200 passes through. In this case, it may be considered only the intersection time with the oncoming vehicle 200 . Therefore, this case can be covered by the conventional avoidance control in which the collision avoidance with respect to the oncoming vehicle 200 is performed.
[0124] Further, in FIG. 12 , the area of the margin time Tcsf and the margin time Tcsb regarding the oncoming vehicle 200 is indicated by a margin area of the oncoming vehicle (ARV). The area of the margin time Tpcf and the margin time Tpsb regarding the pedestrian 300 is indicated by a margin area of the pedestrian (ARP). Further, a distance is obtained by multiplying each margin time and the moving speed of the oncoming vehicle 200 or the pedestrian 300 .
[0125] Next, the description will be made about a relation between the local vehicle 100 , the oncoming vehicle 200 , and the pedestrian 300 on the condition of the above (Expression 14) using FIG. 13 .
[0126] In FIG. 13 , it is assumed that the local vehicle 100 travels on the road RV, makes a right turn at the intersection, and moves to the road RH. When the local vehicle 100 is at a position (A), the oncoming vehicle 200 is at a position (C) on the oncoming vehicle lane of the road RV, and the pedestrian 300 is at a position (E) crossing the road RH. Herein, when the oncoming vehicle 200 travels at the speed V 1 at the position (C), the first intersection time TCP 1 can be obtained from a distance to the first intersection position CP 1 and the speed using (Expression 1). Similarly, when the pedestrian 300 walks at the speed V 2 at the position (E), the second intersection time TCP 2 can be obtained from a distance to the second intersection position CP 2 and the speed using (Expression 2). In the example of FIG. 13 , when the pedestrian 300 passes through the second intersection position CP 2 and is at a position (F) as a state where the condition of (Expression 15) is satisfied, the oncoming vehicle 200 is at a position (D) of FIG. 13 . Since the condition of (Expression 15) is satisfied, the oncoming vehicle 200 at the position (D) is at a position ahead of the first intersection position CP 1 by the margin time Tvsf, and the pedestrian 300 at the position (F) is at a position later by the margin time Tpsb after passing through the second intersection position CP 2 . In this way, at a stage where the local vehicle 100 is at the position (A) before starting the right turn operation at the intersection, it is determined whether the condition of (Expression 15) is satisfied from the positions and the speeds of the oncoming vehicle 200 and the pedestrian 300 . As illustrated in FIG. 13 , in a case where the condition of (Expression 15) is satisfied, the local vehicle 100 determines that a right turn is possible and thus performs the right turn operation. Thereafter, when it is determined that there is a possibility of collision with the pedestrian 300 during a right turn, the local vehicle 100 performs the braking control so as to decelerate or stop to avoid the collision with the pedestrian 300 . However, since the condition of (Expression 15) is satisfied, when passing through the first intersection position CP 1 , the local vehicle passes through the first intersection position CP 1 earlier by the margin time Tcsf with respect to the oncoming vehicle 200 . Therefore, the local vehicle can travel without giving fear and without hindering the course of the oncoming vehicle 200 . Furthermore, even when the pedestrian 300 passes through the second intersection position CP 2 and arrives at the position of the margin time Tpcb, the oncoming vehicle 200 is at a position ahead of the first intersection position CP 1 by the margin time Tcsf. Therefore, in a case where the local vehicle 100 is in a state ready for passing through the second intersection position CP 2 , the oncoming vehicle 200 is at a position ahead of the first intersection position CP 1 by the margin time Tcsf. Accordingly, even in a case where the local vehicle 100 stops until the pedestrian 300 passes through, the oncoming vehicle 200 does not collide with the local vehicle 100 .
[0127] From the above description, in a state where the condition of (Expression 15) is satisfied, even in a case where the local vehicle 100 stops while waiting for the crossing pedestrian 300 to pass through, the oncoming vehicle 200 and the local vehicle 100 do not collide. Therefore, the local vehicle 100 can make a right turn without causing the collision with any of the oncoming vehicle 200 and the pedestrian 300 .
[0128] Next, the description will be described about a relation between the local vehicle 100 , the oncoming vehicle 200 , and the pedestrian 300 on the condition of the above (Expression 15) using FIG. 14 .
[0129] In FIG. 14 , it is assumed that the local vehicle 100 travels on the road RV, makes a right turn at the intersection, and moves to the road RH. When the local vehicle 100 is at a position (A), the oncoming vehicle 200 is at a position (C) on the oncoming vehicle lane of the road RV, and the pedestrian 300 is at a position (E) crossing the road RH. Herein, when the oncoming vehicle 200 travels at the speed V 1 at the position (C), the first intersection time TCP 1 can be obtained from a distance to the first intersection position CP 1 and the speed using (Expression 1). Similarly, when the pedestrian 300 walks at the speed V 2 at the position (E), the second intersection time TCP 2 can be obtained from a distance to the second intersection position CP 2 and the speed using (Expression 2). In the example of FIG. 14 , when the condition of (Expression 15) is not satisfied and the pedestrian 300 passes through the second intersection position CP 2 and is at a position (F), the oncoming vehicle 200 is at a position (D′) of FIG. 14 . Since the condition of (Expression 15) is not satisfied, the oncoming vehicle 200 at the position (D′) is at a position near the first intersection position CP 1 rather than ahead of the first intersection position CP 1 by the margin time Tvsf, and the pedestrian 300 at the position (F) is at a position later by the margin time Tpsb after passing through the second intersection position CP 2 . In this way, at a stage where the local vehicle 100 is at the position (A) before starting the right turn operation at the intersection, it is determined whether the condition of (Expression 15) is satisfied from the positions and the speeds of the oncoming vehicle 200 and the pedestrian 300 . As illustrated in FIG. 14 , in a case where the condition of (Expression 15) is not satisfied, the local vehicle 100 determines that a right turn is not possible and thus does not perform the right turn operation. Thereafter, when it is determined that the oncoming vehicle 200 passes through, the local vehicle 100 performs the right turn operation.
[0130] In the embodiment of FIG. 14 , since the condition of (Expression 15) is not satisfied, even when the local vehicle passes through the first intersection position CP 1 earlier by the margin time Tcsf with respect to the oncoming vehicle 200 , the local vehicle 100 necessarily decelerates or stops for the pedestrian until the pedestrian 300 passes through the second intersection position CP 2 and then arrives at a position of the margin time Tpcb. In this case, since the condition of (Expression 15) is not satisfied, the oncoming vehicle 200 arrives at a position (for example, (D′)) near the first intersection position CP 1 rather than a position earlier by the margin time Tcsf from the first intersection position CP 1 before the pedestrian 300 passes through the second intersection position CP 2 and arrives at a position of the margin time Tpsb. Therefore, the local vehicle 100 stops at the position (B) until the pedestrian 300 passes through, so that there is a collision possibility between the local vehicle 100 and the oncoming vehicle 200 .
[0131] From the above description, since the condition of (Expression 15) is not satisfied, in a case where the local vehicle 100 stops waiting for the crossing pedestrian 300 to pass through, there is a collision possibility between the oncoming vehicle 200 and the local vehicle 100 . Therefore, when the local vehicle 100 makes a right turn on the basis of the determination on no collision only about the oncoming vehicle 200 , there is a possibility to stop in order to avoid the collision with the pedestrian 300 . As a result, there is a collision possibility with the oncoming vehicle 200 , and thus making no right turn is determined to avoid the collision with the oncoming vehicle 200 and the pedestrian 300 .
[0132] Next, the description will be made about another travel scene to which the invention is applied.
[0133] FIG. 15 illustrates a positional relation between the local vehicle 100 traveling on the road (RV), the oncoming vehicle 200 traveling on the oncoming vehicle lane of the local vehicle 100 on the road (RV), and the pedestrian 300 crossing the road (RH) intersecting with the road (RV). In particular, FIG. 15 is different from FIGS. 12, 13, and 14 in the direction where the crossing pedestrian 300 crosses. In other words, FIG. 15 illustrates an embodiment of the travel scene in which the pedestrian 300 crosses the road RH in the same direction as that of the local vehicle 100 traveling on the road RV. Similarly to FIG. 12 , the local vehicle 100 travels at the speed V 0 at the position (A) before entering the intersection, and the oncoming vehicle 200 travels at the speed V 1 at the position (C) on the oncoming vehicle lane. The pedestrian 300 walks at the speed V 2 at the position before the crosswalk or at the position (E) in the middle of crossing the crosswalk. Similarly to FIG. 12 , the first intersection position where the travel path of the local vehicle 100 intersects with the oncoming vehicle 200 is set to CP 1 . The second intersection position where the travel path of the local vehicle 100 intersects with the pedestrian 300 is set to CP 2 . When a distance between the oncoming vehicle 200 at a position (C) and the first intersection position CP 1 is set to L 1 , and a distance between the pedestrian 300 at a position (E) and the second intersection position CP 2 is set to L 2 , the first intersection time TCP 1 becomes L 1 /V 1 , and the second intersection time TCP 2 becomes L 2 /V 2 .
[0134] In FIG. 15 , (D) indicates the position of the oncoming vehicle 200 when the local vehicle 100 crosses before the oncoming vehicle 200 . Herein, when the local vehicle 100 crosses immediately before the oncoming vehicle 200 , it comes to hinder a course of the oncoming vehicle 200 , and gives fear to the driver of the oncoming vehicle 200 . Therefore, in a case where the local vehicle 100 passes through the first intersection position, it is desirable that the oncoming vehicle 200 be at a position sufficiently away from the first intersection position. The sufficient position depends on the speed of the oncoming vehicle 200 . Therefore, the margin time (Tcsf) is set such that the position is changed according to the speed of the oncoming vehicle 200 . In other words, in a case where the first arrival time (TTP 1 ) of the local vehicle 100 is smaller than a time obtained by subtracting the margin time (Tcsf) from the first intersection time (TCP 1 ), the oncoming vehicle 200 is at a position ahead of the first intersection position by the margin time (Tcsf). Therefore, the local vehicle 100 can cross the oncoming vehicle lane without hindering the course of the oncoming vehicle 200 and without giving fear to the driver. In addition, in FIG. 15 , (H) indicates the position of the oncoming vehicle 200 when the local vehicle 100 crosses the oncoming vehicle lane after the oncoming vehicle 200 passes through the first intersection position (CP 1 ). Similarly to FIG. 12 , when the local vehicle 100 crosses the oncoming vehicle lane immediately after the oncoming vehicle 200 passes through the first intersection position, it is not desirable due to fear for contact. In a case where the local vehicle 100 passes through the first intersection position, it is desirable that the oncoming vehicle 200 pass through up to a sufficient position from the first intersection position. The sufficient position depends on the speed of the oncoming vehicle 200 . Therefore, the margin time (Tcsb) is set such that the position is changed according to the speed of the oncoming vehicle 200 . In other words, in a case where the first arrival time (TTP 1 ) of the local vehicle 100 is larger than a time obtained by adding the margin time (Tcsb) to the first intersection time (TCP 1 ), the oncoming vehicle 200 passes through the first intersection position by the margin time (Tcsb). Therefore, the local vehicle 100 can cross the oncoming vehicle lane while keeping a sufficient distance to the oncoming vehicle 200 .
[0135] Similarly, (F) indicates the position of the pedestrian 200 when the local vehicle 100 crosses the crosswalk after the pedestrian 300 passes through the second intersection position (CP 2 ). Herein, when the local vehicle 100 crosses the crosswalk immediately after the pedestrian 300 passes through the second intersection position, it is not desirable due to giving fear to the pedestrian. Therefore, in a case where the local vehicle 100 passes through the second intersection position, it is desirable that the pedestrian 200 pass through up to a sufficient position from the second intersection position. The sufficient position depends on the speed of the pedestrian 300 . Therefore, the margin time (Tpsb) is set such that the position is changed according to the speed of the pedestrian 300 . In other words, in a case where the second arrival time (TTP 2 ) of the local vehicle 100 is larger than a time obtained by adding the margin time (Tpsb) to the second intersection time (TCP 2 ), the pedestrian 300 passes through the second intersection position by the margin time (Tpsb). Therefore, the local vehicle 100 can cross the crosswalk while keeping a sufficient distance to the pedestrian 300 .
[0136] From the above description, as a condition for the local vehicle 100 to pass through the intersection while avoiding the collision with the oncoming vehicle 200 and the pedestrian 300 and without giving fear to the oncoming vehicle 200 and the pedestrian 300 , the local vehicle passes through the first intersection position (CP 1 ) earlier by a time obtained by subtracting the margin time (Tcsf) from the first intersection time (TCP 1 ), and arrives at the second intersection position (CP 2 ) later by a time obtained by adding the margin time (Tpsb) to the second intersection time (TCP 2 ).
[0137] This condition is expressed by (Expression 15) similarly to FIG. 12 .
[0000] TCP 1− TCP 2 >Tpsb+Tcsf−ΔTv (Expression 15)
[0000] Herein, for example, similarly to FIG. 12 , using a relative distance W 12 between the oncoming vehicle 200 and the pedestrian 300 and the speed V 0 of the local vehicle 100 , ΔTv is set to W 12 /V 0 as a time for traveling the relative distance W 12 .
[0138] Further, in FIG. 15 , the area of the margin time Tcsf and the margin time Tcsb regarding the oncoming vehicle 200 is indicated by a margin area of the oncoming vehicle (ARV). The area of the margin time Tpcf and the margin time Tpsb regarding the pedestrian 300 is indicated by a margin area of the pedestrian (ARP). Further, a distance is obtained by multiplying each margin time and the moving speed of the oncoming vehicle 200 or the pedestrian 300 .
[0139] Next, the description will be made about a relation between the local vehicle 100 , the oncoming vehicle 200 , and the pedestrian 300 on the condition of the above (Expression 14). In FIG. 15 , it is assumed that the local vehicle 100 travels on the road RV, makes a right turn at the intersection, and moves to the road RH. When the local vehicle 100 is at a position (A), the oncoming vehicle 200 is at a position (C) on the oncoming vehicle lane of the road RV, and the pedestrian 300 is at a position (E) crossing the road RH. Herein, when the oncoming vehicle 200 travels at the speed V 1 at the position (C), the first intersection time TCP 1 can be obtained from a distance to the first intersection position CP 1 and the speed using (Expression 1). Similarly, when the pedestrian 300 walks at the speed V 2 at the position (E), the second intersection time TCP 2 can be obtained from a distance to the second intersection position CP 2 and the speed using (Expression 2). In the example of FIG. 15 , when the condition of (Expression 15) is satisfied and the pedestrian 300 passes through the second intersection position CP 2 and is at a position (F), the oncoming vehicle 200 is at the position (D) of FIG. 15 . Since the condition of (Expression 15) is satisfied, the oncoming vehicle 200 at the position (D) is at a position ahead of the first intersection position CP 1 by the margin time Tvsf, and the pedestrian 300 at the position (F) is at a position later by the margin time Tpsb after passing through the second intersection position CP 2 . In this way, at a stage where the local vehicle 100 is at the position (A) before starting the right turn operation at the intersection, it is determined whether the condition of (Expression 15) is satisfied from the positions and the speeds of the oncoming vehicle 200 and the pedestrian 300 . As illustrated in FIG. 15 , in a case where the condition of (Expression 15) is satisfied, the local vehicle 100 determines that a right turn is possible and thus makes a right turn. Thereafter, when it is determined that there is a possibility of collision with the pedestrian 300 during a right turn, the local vehicle 100 performs the braking control so as to decelerate or stop to avoid the collision with the pedestrian 300 . However, since the condition of (Expression 15) is satisfied, when passing through the first intersection position CP 1 , the local vehicle passes through the first intersection position CP 1 earlier by the margin time Tcsf with respect to the oncoming vehicle 200 . Therefore, the local vehicle can travel without giving fear and without hindering the course of the oncoming vehicle 200 . Furthermore, even when the pedestrian 300 passes through the second intersection position CP 2 and arrives at the position of the margin time Tpcb, the oncoming vehicle 200 is at a position ahead of the first intersection position CP 1 by the margin time Tcsf. Therefore, in a case where the local vehicle 100 is in a state ready for passing through the second intersection position CP 2 , the oncoming vehicle 200 is at a position ahead of the first intersection position CP 1 by the margin time Tcsf. Accordingly, even in a case where the local vehicle 100 stops until the pedestrian 300 passes through, the oncoming vehicle 200 does not collide with the local vehicle 100 .
[0140] From the above description, in a state where the condition of (Expression 15) is satisfied, even in a case where the local vehicle 100 stops while waiting for the crossing pedestrian 300 to pass through, the oncoming vehicle 200 and the local vehicle 100 do not collide. Therefore, the local vehicle 100 can make a right turn without causing the collision with any of the oncoming vehicle 200 and the pedestrian 300 .
[0141] Next, the description will be described about a relation between the local vehicle 100 , the oncoming vehicle 200 , and the pedestrian 300 on the condition of the above (Expression 15) using FIG. 16 . FIG. 16 is different from FIG. 14 in that the pedestrian 300 crosses the road RH in the same direction as that of the local vehicle 100 traveling on the road RV.
[0142] In FIG. 16 , it is assumed that the local vehicle 100 travels on the road RV, makes a right turn at the intersection, and moves to the road RH. When the local vehicle 100 is at a position (A), the oncoming vehicle 200 is at a position (C) on the oncoming vehicle lane of the road RV, and the pedestrian 300 is at a position (E) crossing the road RH. Herein, when the oncoming vehicle 200 travels at the speed V 1 at the position (C), the first intersection time TCP 1 can be obtained from a distance to the first intersection position CP 1 and the speed using (Expression 1). Similarly, when the pedestrian 300 walks at the speed V 2 at the position (E), the second intersection time TCP 2 can be obtained from a distance to the second intersection position CP 2 and the speed using (Expression 2). In the example of FIG. 16 , when the condition of (Expression 15) is not satisfied and the pedestrian 300 passes through the second intersection position CP 2 and is at a position (F), the oncoming vehicle 200 is at a position (D′) of FIG. 16 . Since the condition of (Expression 15) is not satisfied, the oncoming vehicle 200 at the position (D′) is at a position near the first intersection position CP 1 rather than ahead of the first intersection position CP 1 by the margin time Tvsf, and the pedestrian 300 at the position (F) is at a position later by the margin time Tpsb after passing through the second intersection position CP 2 . In this way, at a stage where the local vehicle 100 is at the position (A) before starting the right turn operation at the intersection, it is determined whether the condition of (Expression 15) is satisfied from the positions and the speeds of the oncoming vehicle 200 and the pedestrian 300 . As illustrated in FIG. 16 , in a case where the condition of (Expression 15) is not satisfied, the local vehicle 100 determines that a right turn is not possible and thus does not make a right turn. Thereafter, when it is determined that the oncoming vehicle 200 passes through, the local vehicle 100 performs the right turn operation.
[0143] In the embodiment of FIG. 16 , since the condition of (Expression 15) is not satisfied, even when the local vehicle passes through the first intersection position CP 1 earlier by the margin time Tcsf with respect to the oncoming vehicle 200 , the local vehicle 100 necessarily decelerates or stops for the pedestrian until the pedestrian 300 passes through the second intersection position CP 2 and then arrives at a position of the margin time Tpcb. In this case, since the condition of (Expression 15) is not satisfied, the oncoming vehicle 200 arrives at a position (for example, (D′)) near the first intersection position CP 1 rather than a position earlier by the margin time Tcsf from the first intersection position CP 1 before the pedestrian 300 passes through the second intersection position CP 2 and arrives at a position of the margin time Tpsb. Therefore, the local vehicle 100 stops at the position (B) until the pedestrian 300 passes through, so that there is a collision possibility between the local vehicle 100 and the oncoming vehicle 200 .
[0144] From the above description, since the condition of (Expression 15) is not satisfied, in a case where the local vehicle 100 stops waiting for the crossing pedestrian 300 to pass through, there is a collision possibility between the oncoming vehicle 200 and the local vehicle 100 . Therefore, when the local vehicle 100 makes a right turn on the basis of the determination on no collision only about the oncoming vehicle 200 , there is a possibility to stop in order to avoid the collision with the pedestrian 300 . As a result, there is a collision possibility with the oncoming vehicle 200 , and thus making no right turn is determined to avoid the collision with the oncoming vehicle 200 and the pedestrian 300 .
[0145] FIG. 17 illustrates another embodiment of the invention. FIG. 17 is a diagram for describing an embodiment in a case where the local vehicle 100 makes a left turn at the intersection.
[0146] FIG. 17 illustrates a positional relation between the local vehicle 100 traveling on the road (RV), a light vehicle (bicycle) 400 traveling on the oncoming direction of the local vehicle 100 on the road (RV), and the pedestrian 300 crossing the road (RH) intersecting with the road (RV). It is assumed that the local vehicle 100 travels at the speed V 0 at a position (A) before entering the intersection, the light vehicle (bicycle) 400 travels at a speed V 3 at a position (D), and the pedestrian 300 walks at the speed V 2 at a position (G) before the crosswalk. In addition, the first intersection position where the travel path of the local vehicle 100 intersects with the light vehicle (bicycle) 400 is set to CP 1 . The second intersection position where the travel path of the local vehicle 100 intersects with the pedestrian 300 is set to CP 2 . When a distance between the light vehicle (bicycle) 400 at the position (D) and the first intersection position CP 1 is set to L 1 , and a distance between the pedestrian 300 at the position (G) and the second intersection position CP 2 is set to L 2 , the first intersection time TCP 1 becomes L 1 /V 1 , and the second intersection time TCP 2 becomes L 2 /V 2 .
[0147] In FIG. 17 , (E) indicates the position of the light vehicle (bicycle) 400 when the local vehicle 100 crosses before the light vehicle (bicycle) 400 . Herein, when the local vehicle 100 crosses immediately before the light vehicle (bicycle) 400 , it comes to hinder a course of the light vehicle (bicycle) 400 , and gives fear to the light vehicle (bicycle) 400 . Therefore, in a case where the local vehicle 100 passes through the first intersection position, it is desirable that the light vehicle (bicycle) 400 be at a position sufficiently away from the first intersection position. The sufficient position depends on the speed of the light vehicle (bicycle) 400 . Therefore, the margin time (Tbsf) is set such that the position is changed according to the speed of the light vehicle (bicycle) 400 . In other words, in a case where the first arrival time (TTP 1 ) of the local vehicle 100 is smaller than a time obtained by subtracting the margin time (Tbsf) from the first intersection time (TCP 1 ), the light vehicle (bicycle) 400 is at a position ahead of the first intersection position by the margin time (Tbsf). Therefore, the local vehicle 100 can cross the oncoming vehicle lane without hindering the course of the light vehicle (bicycle) 400 and without giving fear to the driver. In addition, in FIG. 17 , (F) indicates the position of the light vehicle (bicycle) 400 when the local vehicle 100 passes through the first intersection position CP 1 after the light vehicle (bicycle) 400 passes through the first intersection position (CP 1 ). Herein, when the local vehicle 100 crosses the oncoming vehicle lane immediately after the light vehicle (bicycle) 400 passes through the first intersection position, it is not desirable due to fear for contact. In a case where the local vehicle 100 passes through the first intersection position, it is desirable that the light vehicle (bicycle) 400 pass through up to a sufficient position from the first intersection position. The sufficient position depends on the speed of the light vehicle (bicycle) 400 . Therefore, the margin time (Tbsb) is set such that the position is changed according to the speed of the light vehicle (bicycle) 400 . In other words, in a case where the first arrival time (TTP 1 ) of the local vehicle 100 is larger than a time obtained by adding the margin time (Tcsb) to the first intersection time (TCP 1 ), the light vehicle (bicycle) 400 passes through the first intersection position by the margin time (Tbsb). Therefore, the local vehicle 100 passes through the first intersection position CP 1 while keeping a sufficient distance to the light vehicle (bicycle) 400 .
[0148] Similarly, in FIG. 17 , (H) indicates the position of the pedestrian 200 when the local vehicle 100 crosses the crosswalk after the pedestrian 300 passes through the second intersection position (CP 2 ). Herein, when the local vehicle 100 crosses the crosswalk immediately after the pedestrian 300 passes through the second intersection position, it is not desirable due to giving fear to the pedestrian. Therefore, in a case where the local vehicle 100 passes through the second intersection position, it is desirable that the pedestrian 200 pass through up to a sufficient position from the second intersection position. The sufficient position depends on the speed of the pedestrian 300 . Therefore, the margin time (Tpsb) is set such that the position is changed according to the speed of the pedestrian 300 . In other words, in a case where the second arrival time (TTP 2 ) of the local vehicle 100 is larger than a time obtained by adding the margin time (Tpsb) to the second intersection time (TCP 2 ), the pedestrian 300 passes through the second intersection position by the margin time (Tpsb). Therefore, the local vehicle 100 can cross the crosswalk while keeping a sufficient distance to the pedestrian 300 .
[0149] From the above description, as a condition for the local vehicle 100 to pass through the intersection while avoiding the collision with the light vehicle (bicycle) 400 and the pedestrian 300 and without giving fear to the light vehicle (bicycle) 400 and the pedestrian 300 , the local vehicle passes through the first intersection position (CP 1 ) earlier by a time obtained by subtracting the margin time (Tbsf) from the first intersection time (TCP 1 ), and arrives at the second intersection position (CP 2 ) later by a time obtained by adding the margin time (Tpsb) to the second intersection time (TCP 2 ).
[0150] Herein, the following Expression is defined.
[0000] TTP 1 +ΔTv 2 =TTP 2 [Expression 16]
[0151] Then, the above condition becomes as follows.
[0000] TCP 1 −Tbsf>TTP 1, and
[0000] TCP 2 +Tpsb<TTP 2. [Expression 17]
[0152] Therefore, the following Expression is obtained from [Expression 16] and [Expression 17].
[0000] TCP 1> TTP 1 +Tbsf , and
[0000] TCP 2< TTP 1+Δ Tv 2 −Tpsb [Expression 18]
[0153] To sum up, the following Expression is obtained.
[0000] TCP 2−Δ Tv 2 +Tpsb<TTP 1, and
[0000] TTP 1< TCP 1 −Tbsf. [Expression 19]
[0154] Therefore, the following Expression is obtained.
[0000] TCP 1 −TCP 2 >Tpsb+Tbsf−ΔTv 2 [Expression 20]
[0155] Herein, for example, as illustrated in FIG. 17 , using the relative distance W 12 between the light vehicle (bicycle) 400 and the pedestrian 300 and the speed V 0 of the local vehicle 100 , ΔTv 2 is set to W 12 /V 0 as a time for traveling the relative distance W 12 .
[0156] Further, as another condition other than the above, the local vehicle passes through the first intersection position (CP 1 ) after a time obtained by adding the margin time (Tbsb) to the first intersection time (TCP 1 ), that is, making a left turn after the light vehicle (bicycle) 400 passes through. In this case, it may be considered only the intersection time with the light vehicle (bicycle) 400 . Therefore, this can be covered by the conventional avoidance control in which the collision avoidance to the light vehicle (bicycle) 400 is performed.
[0157] Further, in FIG. 17 , the area of the margin time Tbsf and the margin time Tbsb regarding the light vehicle (bicycle) 400 is indicated by a margin area (ARB) of the light vehicle (bicycle) (ARG). The area of the margin time Tpcf and the margin time Tpsb regarding the pedestrian 300 is indicated by a margin area of the pedestrian (ARP). Further, a distance is obtained by multiplying each margin time and the moving speed of the light vehicle (bicycle) 400 or the pedestrian 300 .
[0158] FIG. 17 illustrates a travel scene in which the light vehicle (bicycle) 400 travels in place of the oncoming vehicle 200 of FIG. 12 and the local vehicle 100 makes a left turn, which can be considered similarly to the descriptions of FIGS. 12, 13, and 14 .
[0159] In FIG. 17 , when the pedestrian 300 passes through the second intersection position CP 2 and is at a position (H) as a case where the condition of (Expression 20) is satisfied, the light vehicle (bicycle) 400 is at the position (E) of FIG. 13 . Since the condition of (Expression 20) is satisfied, the light vehicle (bicycle) 400 at the position (E) is at a position ahead of the first intersection position CP 1 by the margin time Tbsf, and the pedestrian 300 at the position (H) is at a position later by the margin time Tpsb after passing through the second intersection position CP 2 . In this way, at a stage where the local vehicle 100 is at the position (A) before starting a left turn operation at the intersection, it is determined whether the condition of (Expression 20) is satisfied from the positions and the speeds of the light vehicle (bicycle) 400 and the pedestrian 300 . In a case where the condition of (Expression 20) is satisfied, the local vehicle 100 determines that a left turn is possible and thus performs the left turn operation. Thereafter, when it is determined that there is a possibility of collision with the pedestrian 300 during a left turn, the local vehicle 100 performs the braking control so as to decelerate or stop to avoid the collision with the pedestrian 300 . However, since the condition of (Expression 20) is satisfied, when passing through the first intersection position CP 1 , the local vehicle passes through the first intersection position CP 1 earlier by the margin time Tbsf with respect to the light vehicle (bicycle) 400 . Therefore, the local vehicle can travel without giving fear and without hindering the course of the light vehicle (bicycle) 400 . Furthermore, even when the pedestrian 300 passes through the second intersection position CP 2 and arrives at the position of the margin time Tpcb, the light vehicle (bicycle) 400 is at a position ahead of the first intersection position CP 1 by the margin time Tbsf. Therefore, in a case where the local vehicle 100 is in a state ready for passing through the second intersection position CP 2 , the light vehicle (bicycle) 400 is at a position ahead of the first intersection position CP 1 by the margin time Tbsf. Accordingly, even in a case where the local vehicle 100 stops until the pedestrian 300 passes through, the light vehicle (bicycle) 400 does not collide with the local vehicle 100 . From the above description, in a state where the condition of (Expression 20) is satisfied, even in a case where the local vehicle 100 stops while waiting for the pedestrian 300 to pass through, the light vehicle (bicycle) 400 and the local vehicle 100 do not collide. Therefore, the local vehicle 100 can make a left turn without causing the collision with any of the light vehicle (bicycle) 400 and the pedestrian 300 .
[0160] Similarly, the description will be made using FIG. 17 about a state where the condition of (Expression 20) is not satisfied. When the pedestrian 300 passes through the second intersection position CP 2 and is at the position (H), the light vehicle (bicycle) 400 is at a position (E′) of FIG. 17 . Since the condition of (Expression 20) is not satisfied, the light vehicle (bicycle) 400 at the position (E′) is at a position near the first intersection position CP 1 rather than ahead of the first intersection position CP 1 by the margin time Tbsf, and the pedestrian 300 at the position (H) is at a position later by the margin time Tpsb after passing through the second intersection position CP 2 . In this way, at a stage where the local vehicle 100 is at the position (A) before starting a left turn operation at the intersection, it is determined whether the condition of (Expression 20) is satisfied from the positions and the speeds of the light vehicle (bicycle) 400 and the pedestrian 300 . In a case where the condition of (Expression 20) is not satisfied, the local vehicle 100 determines that a left turn is not possible and thus does not make a left turn. Thereafter, when it is determined that the light vehicle (bicycle) 400 passes through, the local vehicle 100 performs the left turn operation. More specifically, in a case where the condition of (Expression 20) is not satisfied, even when the local vehicle passes through the first intersection position CP 1 earlier by the margin time Tbsf with respect to the light vehicle (bicycle) 400 , the local vehicle 100 necessarily decelerates or stops for the pedestrian until the pedestrian 300 passes through the second intersection position CP 2 and then arrives at a position of the margin time Tpcb. In this case, since the condition of (Expression 20) is not satisfied, the light vehicle (bicycle) 400 arrives at a position (for example, (E′)) near the first intersection position CP 1 rather than a position earlier by the margin time Tbsf from the first intersection position CP 1 before the pedestrian 300 passes through the second intersection position CP 2 and arrives at a position of the margin time Tpsb. Therefore, the local vehicle 100 stops at the position (B) until the pedestrian 300 passes through, so that there is a collision possibility between the local vehicle 100 and the light vehicle (bicycle) 400 . From the above description, since the condition of (Expression 20) is not satisfied, in a case where the local vehicle 100 stops waiting for the pedestrian 300 to pass through, there is a collision possibility between the light vehicle (bicycle) 400 and the local vehicle 100 . Therefore, when the local vehicle 100 makes a left turn on the basis of the determination on no collision only about the light vehicle (bicycle) 400 , there is a possibility to stop in order to avoid the collision with the pedestrian 300 . As a result, there is a collision possibility with the light vehicle (bicycle) 400 , and thus making no left turn is determined to avoid the collision with the light vehicle (bicycle) 400 and the pedestrian 300 .
[0161] Still another embodiment of the invention will be described using FIG. 18 .
[0162] FIG. 18 illustrates a travel scene in which a four-lane road is assumed together with the roads RV and RH. In addition, the local vehicle 100 travels on the road RV, and the oncoming vehicle 200 and an oncoming vehicle 500 travel on the oncoming vehicle lane of the road RV. In addition, on the road RH after the local vehicle 100 makes a right turn at the intersection, the pedestrian 300 crosses the road RH. Further, in FIG. 18 , the pedestrian 300 moves in the oncoming direction to that of the local vehicle 100 traveling on the road RV, but it does not matter even in the case of the same direction. The speed of the local vehicle 100 is V 0 , and the speeds of the oncoming vehicle 200 and the oncoming vehicle 500 are respectively V 1 and V 4 . In addition, the speed of the pedestrian 300 is V 2 . As illustrated in FIG. 18 , in a case where the local vehicle 100 is at a position (A′), the oncoming vehicle 200 is at the position (D), and the oncoming vehicle 500 is at a position (J), when the front side is detected using the external environment recognition device 80 mounted in the local vehicle 100 , the oncoming vehicle 200 at the position (D) and the oncoming vehicle 500 at the position (J) come to be in the same direction on a straight line when viewed from the local vehicle 100 . The oncoming vehicle 500 at the position (J) comes to be concealed by the oncoming vehicle at the position (D) when viewed from the local vehicle 100 at the position (A′). Therefore, the oncoming vehicle 500 may be not detected by the external environment recognition device 80 of the local vehicle 100 . In this way, when the oncoming vehicle 500 and the oncoming vehicle 200 are kept on traveling on the same straight line when viewed from the local vehicle 100 , the external environment recognition device 80 of the local vehicle 100 cannot continuously detect the oncoming vehicle 500 . Therefore, it is not possible to recognize the presence of the oncoming vehicle 500 . Herein, the description will be made about a relation between the oncoming vehicle 200 and the oncoming vehicle 500 which cannot be detected by the external environment recognition device 80 of the local vehicle 100 .
[0163] As illustrated in FIG. 18 , a distance in the lateral direction between the local vehicle 100 and the oncoming vehicle 200 is set to Wvv 1 , a distance in the lateral direction between the local vehicle 100 and the oncoming vehicle 500 is set to Wvv 4 , a distance in the longitudinal direction between the local vehicle 100 and the oncoming vehicle 200 is set to Lv 1 , and a distance in the longitudinal direction between the local vehicle 100 and the oncoming vehicle 500 is set to Lv 4 . In a case where the oncoming vehicle 200 and the oncoming vehicle 500 are on the same straight line when viewed from the local vehicle 100 , the following relation is established.
[0000] Lv 1: Lv 4= Wvv 1: Wvv 4= V 0+ V 1: V 0+ V 4 [Expression 21]
[0164] Herein, an intersecting point between the travel path of the local vehicle 100 and the oncoming vehicle 500 is set to a third intersection position CP 3 , and a distance between the oncoming vehicle 500 and the third intersection position CP 3 is set to L 4 . In a case where the oncoming vehicle 500 and the oncoming vehicle 200 are on the same straight line, [Expression 21] is established. Therefore, in a case where the external environment recognition device 80 of the local vehicle 100 cannot detect the oncoming vehicle 500 even when there is the oncoming vehicle 500 , the speed and the distance Lv 4 of the oncoming vehicle 500 become as follows.
[0000] V 4=( Wvv 4+ Wvv 1)× V 1+( Wvv 4− Wvv 1)+ Wvv 1× V 0 [Expression 22]
[0000] Lv 4=( Wvv 4+ Wvv 1)× Lv 1 [Expression 23]
[0165] Herein, the distances from the local vehicle 100 to the first intersection position CP 1 and the third intersection position CP 3 are set to DLv 1 and DLv 4 .
[0000] L 4= Lv 4− DLv 4=( Wvv 4+ Wvv 1)×( L 1− DLv 1)− DLv 4 [Expression 24]
[0166] Herein, the distances DLv 1 and DLv 4 from the local vehicle 100 to the first intersection position CP 1 and the third intersection position CP 3 , the distance Wvv 1 in the lateral direction between the local vehicle 100 and the oncoming vehicle 200 , and the distance Wvv 4 in the lateral direction between the local vehicle 100 and the oncoming vehicle 500 can be obtained from the road map information, the intersection map information, and the current position of the local vehicle 100 . Therefore, it is possible to virtually obtain the speed V 4 and the distance L 4 to the third intersection position CP 3 with respect to the oncoming vehicle 500 which is assumed to be concealed by the oncoming vehicle 200 and thus not detected. Therefore, even when the oncoming vehicle 500 cannot be detected, it is possible to predict a time (third intersection time TCP 3 ) when the oncoming vehicle 500 virtually arrives at the third intersection position CP 3 .
[0000] TCP 3= L 4+ V 4 [Expression 25]
[0167] From the above description, the third intersection position CP 3 is set for the virtual oncoming vehicle 500 , and thus the third intersection time TCP 3 taken for arriving at the third intersection position can be obtained. Then, using the first intersection time TCP 1 , the second intersection time TCP 2 , and the third intersection time TCP 3 , in a case where the local vehicle 100 makes a right turn, it is possible to determine whether there is a possibility to conflict with the oncoming vehicle 200 , the virtual oncoming vehicle 500 , and the pedestrian 300 . In a case where there is a possibility suggesting the presence of the virtual oncoming vehicle 500 , it is possible to warn the driver about the possibility suggesting the presence of the virtual oncoming vehicle 500 in advance using the alarm means 69 .
[0168] Next, the description will be made about a case where three moving bodies (the oncoming vehicle 200 , the oncoming vehicle 500 , and the pedestrian 300 ) and the travel path of the local vehicle 100 intersect with each other when there is the virtual oncoming vehicle 500 , or there is the oncoming vehicle 500 in reality.
[0169] As a magnitude relation between three intersection times (TCP 1 , TCP 3 , and TCP 2 ), there are six cases as illustrated in FIG. 19 . The intersection time is a time to arrive at each intersection position (CP 1 , CP 2 , and CP 3 ). Therefore, Case 1 indicates that the pedestrian 300 is the first to arrive at the second intersection position CP 2 , the oncoming vehicle 500 is the next to arrive at the third intersection position CP 3 , and the oncoming vehicle 200 is the last to arrive at the first intersection position CP 1 ) as timings for the respective moving bodies (the oncoming vehicle 200 , the pedestrian 300 , and the oncoming vehicle 500 ) to arrive at the respective intersection positions (CP 1 , CP 2 , and CP 3 ).
[0170] In Case 1, the respective moving bodies (the oncoming vehicle 200 , the oncoming vehicle 500 , and the pedestrian 300 ) arrive at the respective intersection positions (the first intersection position CP 1 , the third intersection position CP 3 , and the second intersection position CP 2 ) in an order of the intersection position farthest away from the local vehicle 100 . Therefore, in a case where it is determined that there is no collision possibility with the oncoming vehicle 200 and the following condition is established, it is determined that the local vehicle can make a right turn.
[0000] TCP 1− TCP 3≧ T 13 [Expression 26]
[0171] (where, T 13 : margin time)
[0000] TCP 3− TCP 2≧ T 32 [Expression 27]
[0172] (where, T 32 : margin time)
[0173] In this case, when there is no collision possibility with the oncoming vehicle 200 and the condition of (Expression 26) is established, the oncoming vehicle 200 is at a position of the margin time even when the local vehicle 100 stops at a position ahead of the third intersection position CP 3 , and waits for the oncoming vehicle 500 to pass through the third intersection position CP 3 . Therefore, the collision possibility with the oncoming vehicle 200 is low. In addition, when the condition of (Expression 27) is established, the oncoming vehicle 500 is at a position of the margin time even when the local vehicle 100 stops at a position ahead of the second intersection position CP 2 , and waits for the pedestrian 300 to pass through the second intersection position CP 2 . Therefore, the collision possibility with the oncoming vehicle 500 is low.
[0174] Case 2 indicates that the oncoming vehicle 500 is the first to arrive at the third intersection position CP 3 . Therefore, in a case where it is determined that the collision possibility with the oncoming vehicle 200 is low and the following condition is established, it is determined that the local vehicle can make a right turn.
[0000] TCP 1− TCP 3≧ T 13 [Expression 28]
[0175] (where, T 13 : margin time)
[0000] TCP 1− TCP 2≧ T 12 [Expression 29]
[0176] (where, T 12 : margin time)
[0177] In this case, since there is no collision possibility with the oncoming vehicle 200 and the condition of (Expression 28) is established, the oncoming vehicle 200 is at a position of the margin time even when the local vehicle 100 stops at a position ahead of the third intersection position CP 3 , and waits for the oncoming vehicle 500 to pass through the third intersection position CP 3 . Therefore, the collision possibility with the oncoming vehicle 200 is low. Furthermore, since the condition of (Expression 29) is established, the collision possibility with the oncoming vehicle 200 is low even when the local vehicle 100 stops at a position ahead of the second intersection position CP 2 and waits for the pedestrian 300 to pass through the second intersection position CP 2 .
[0178] Case 3 indicates that the pedestrian 300 is the first to arrive at the second intersection position CP 2 and the oncoming vehicle 500 is the last to arrive at the third intersection position CP 3 . Therefore, in a case where it is determined that there is no collision possibility with the oncoming vehicle 200 and the following condition is established, it is determined that the local vehicle can make a right turn.
[0000] TCP 1− TCP 2≧ T 12 [Expression 30]
[0179] (where, T 12 : margin time)
[0180] In this case, since the oncoming vehicle 500 arrives late at the third intersection position CP 3 compared to the oncoming vehicle 200 , the collision possibility between the oncoming vehicle 500 and the local vehicle 100 is low.
[0181] Case 4 indicates that the oncoming vehicle 500 is the first to arrive at the third intersection position CP 3 and the pedestrian 300 is the last to arrive at the second intersection position CP 2 . Therefore, in a case where it is determined that there is no collision possibility with the oncoming vehicle 200 and the following condition is established, it is determined that the local vehicle can make a right turn.
[0000] TCP 1− TCP 3≧ T 13 [Expression 31]
[0182] (where, T 13 : margin time)
[0000] TCP 2− TCP 3≧ T 23 [Expression 32]
[0183] (where, T 23 : margin time)
[0184] In this case, even when the local vehicle 100 stops at a position ahead of the third intersection position CP 3 in order to wait for the oncoming vehicle 500 to pass through, and the local vehicle 100 passes through the third intersection position after the oncoming vehicle 500 passes through on the basis of the condition of (Expression 31), the collision possibility with the oncoming vehicle 200 is low. In addition, even when the local vehicle arrives at the second intersection position CP 2 after the oncoming vehicle 500 passes through on the basis of the condition of (Expression 32), the collision possibility with the pedestrian 300 is low. However, since there is a high possibility to hinder the course of the pedestrian 300 when the local vehicle passes through in front of the pedestrian 300 , it is desirable that the margin time T 23 be set to be sufficiently large.
[0185] Case 5 indicates that the respective moving bodies (the oncoming vehicle 200 , the oncoming vehicle 500 , and the pedestrian 300 ) arrive at the respective intersection positions (the first intersection position CP 1 , the third intersection position CP 3 , and the second intersection position CP 2 ) in an order of the intersection position closest to the local vehicle 100 . Therefore, when it is determined that there is no collision possibility with any one of the oncoming vehicle 200 , the oncoming vehicle 500 , and the pedestrian 300 , it is determined that the local vehicle can make a right turn.
[0186] Case 6 indicates that the oncoming vehicle 200 is the first to arrive at the first intersection position CP 1 and the pedestrian 300 is the next to arrive at the second intersection position CP 2 . Therefore, in a case where it is determined that there is no collision possibility with the oncoming vehicle 200 and the following condition is established, it is determined that the local vehicle can make a right turn.
[0000] TCP 3− TCP 2≧ T 32 [Expression 33]
[0187] (where, T 32 : margin time)
[0000] TCP 1<0 [Expression 34]
[0188] (after the oncoming vehicle 200 passes through the first intersection position CP 1 )
[0189] In this case, when the local vehicle 100 passes through the first intersection position CP 1 after the oncoming vehicle 200 passes through the first intersection position CP 1 , and even when the local vehicle 100 stops at a position ahead of the second intersection position CP 2 in order to wait for the pedestrian 300 to pass through the second intersection position CP 2 on the basis of the condition of (Expression 33), the collision possibility with the oncoming vehicle 500 is low. However, in a case where the local vehicle 100 passes through the first intersection position CP 1 before the oncoming vehicle 200 passes through the first intersection position CP 1 , and when the local vehicle 100 stops at a position ahead of the second intersection position CP 2 in order to wait for the pedestrian 300 to pass through the second intersection position CP 2 , the collision possibility with the oncoming vehicle 200 is increased. Therefore, it is desirable not to make a right turn.
[0190] Hitherto, the description has been made about the avoidance control performed in the invention in which the collision possibility with the moving body around the local vehicle 100 is determined, and in a case where there is a collision possibility, an alarm is informed to the driver or the brake device is automatically controlled to decelerate the local vehicle 100 . Herein, in the vehicle control device 60 of the local vehicle 100 , the collision avoidance control means 66 performs the avoidance control, and the release means 615 releases the avoidance control.
[0191] Hereinafter, the description will be made about the release of the automatic control such as the collision avoidance. In the invention, there is a travel function in which a right/left turn at the intersection is automatically determined using a collision possibility determination of the invention in addition to a drive support function of assisting the driver's operation. Specifically, there is an example in which a travel path of the local vehicle 100 is set on the basis of a predetermined travel route, and the local vehicle 100 automatically travels on the basis of the path. In this case, according to the invention, a right/left turn is determined when making a right/left turn at the intersection. In a case where it is determined that a right turn is not possible, the local vehicle 100 is automatically stopped before making a right turn. In this way, the invention is able to be operated as the drive support for the driver and the control determination at the time of automatic traveling.
[0192] In the invention, the moving body and the obstacle around the local vehicle 100 are detected, the collision possibility determination is performed, and the drive support for the driver and the automatic traveling control are performed. At this time, it is considered that a driver is in the local vehicle 100 and the operation of the local vehicle 100 is performed by a driver's final determination. Therefore, in a case where the operation is performed by the driver's final determination, for example, the collision avoidance control is necessarily released on the basis of the right/left turn determination at the intersection as described in the embodiments of the invention and the driver's operation is performed with priority. The control is released by the release means 615 in the collision avoidance control means 66 of the vehicle control device 60 of the invention.
[0193] FIG. 20 illustrates a diagram illustrating a configuration of the release means 615 . The release means 615 includes a manual operation change determination means 6151 and a release pattern setting means 6152 . The manual operation change determination means 6151 detects whether the driver of the local vehicle 100 changes an operation of the local vehicle 100 . Then, when the manual operation change determination means 6151 detects that the driver performs an operation, the control operation of the vehicle control device 60 is released on the basis of a release procedure set by the release pattern setting means 6152 .
[0194] Herein, as a specific embodiment of the manual operation change determination means 6151 , for example, there is a method in which an amount of change in steering angle, an amount of change in depressing brake pedal, an amount of change in accelerator opening, an amount of change in yaw rate, and an amount of change in lateral acceleration of the local vehicle 100 are detected. In a case where any one of these values becomes larger than a predetermined value set in advance, it is determined that the driver changes the operation of the local vehicle 100 .
[0195] In addition, as a specific embodiment of the release pattern setting means 6152 , for example, there is a method in which, when the manual operation change determination means 6151 determines that the driver changes the operation of the local vehicle 100 , the control command of the vehicle control device 60 is released by taking a predetermined time. When the control command is released at once after the driver's operation is determined, the driver's operation and the operation of the automatic control are likely to be abruptly switched. Further, there may occur instability in the behavior of the local vehicle 100 by the abrupt switching in operation. Therefore, the control command of the vehicle control device 60 is released to be zero by taking a predetermined time. With this configuration, it is possible to smoothly switch the operation from the control operation to the driver's operation. However, when the switching time becomes long, the driver's operation is not performed with priority as much as that time. Therefore, it is desirable that the time for completely releasing the control command be set to be short. Furthermore, when the control command is released, there may be a method of freely setting a ratio of the control command together with the time instead of making the control command zero at a constant ratio.
[0196] Further, the embodiments of the invention have been described about the travel scene where the vehicle travels to the left side as a specific example. In a case where the vehicle travels to the right side, the same effects can be obtained. Specifically, in a case where the vehicle travels to the right side, the travel scene of a right turn in the embodiments of the invention corresponds to the travel scene of a left turn. In a case where the vehicle travels to the right side, the travel scene of a left turn in the embodiments of the invention corresponds to the travel scene of a right turn. While there is a difference between the right-side travel and the left-side travel of the vehicle, both travels can be handled substantially with the same manner.
REFERENCE SIGNS LIST
[0000]
10 drive source
20 transmission
30 drive source control device
40 braking control device
50 communication device
60 vehicle control device
61 local vehicle position information processing means
62 road information processing means
63 external environment information processing means
64 local vehicle information processing means
65 right/left turn determination processing means
66 collision avoidance control means
67 operation amount calculation means
68 the display means
69 alarm means
70 control network
80 external environment recognition device
90 brake device
100 vehicle, local vehicle
110 right/left turn determination means
120 alarm device
130 display device
140 communication means
200 oncoming vehicle
300 pedestrian
400 light vehicle (bicycle)
500 oncoming vehicle
601 moving body detection data
602 road information acquisition data
603 local vehicle status detection data
604 first intersection time estimation means
605 second intersection time estimation means
606 first arrival time estimation means
607 second arrival time estimation means
608 predicted time comparison means
609 collision determination means
610 control select means
611 first control means
612 second control means
613 third control means
614 fourth control means
615 release means
616 select means | When turning right (left) at an intersection and crossing an oncoming vehicle lane, this system makes it possible to avoid blocking travel of or colliding with a moving body moving in the oncoming vehicle lane due to stopping in the oncoming vehicle lane, and to avoid colliding with a moving body after crossing the oncoming vehicle lane. Given two or more moving bodies present in the advancement direction on the path of the local vehicle, the external environment is detected before the local vehicle intersects with the path of a first moving body, which will first intersect the local vehicle path; if at least two moving bodies are detected, i.e., the first moving body and a second moving body which has a path in which the position of intersection with the path of the local vehicle is further than the position of intersection between the path of the local vehicle and the path of the first moving body, then a first intersection time, at which the first position of intersection between the planned path of the local vehicle and the predicted path of the first moving body is reached, and a second intersection time, at which a second position of intersection between the planned path of the local vehicle and the predicted path of the second moving body is reached, are calculated, and on the basis of the difference between the first intersection time and the second intersection time, the deceleration relative to the first moving body and the second moving body is changed. | 1 |
FIELD OF THE INVENTION
The present invention relates to a remote control system, and more particularly to a remote radio control system which cannot be accidentally triggered by a spurious radio signal.
BACKGROUND
As radio controlled systems, such as for garage door openers and the like, as well as other radio transmitters such as walkie-talkies, become more popular and more prevalent, a serious danger has arisen in that the assigned frequencies of such devices have become so crowded that a radio signal from one transmitter may interfere with the operation of a radio controlled device intended to be operated by an entirely different transmitter. By way of example, a serious problem has arisen in the attempted use of radio control of special effects in the entertainment industry such as, for example, turning special effects lights on and off and/or actuating confetti launching cannons; such lights and cannons being ceiling-mounted or mounted in other locations of difficult access. In these situations, the systems usually must be set up a number of hours before the performance, and they must remain ready to operate at the critical time during the performance. However, such systems are subject to the ever present danger that they may be set off prematurely by a passing police car, or a security guard operating a walkie-talkie, or any other spurious radio signal with a frequency sufficiently close to the frequency of the radio receiver in the theatrical system. Such premature actuations have become unacceptably frequent in recent years, and they usually ruin the theatrical performance, as well as create a disappointed and unhappy audience.
SUMMARY
The present invention solves this serious problem by creating a remote radio control transmitter capable of generating and transmitting two entirely different radio signals, and creating a radio receiver receptive to both of such different signals in a manner whereby the first signal arms or activates the circuit so as to be receptive to the second signal to actuate the theatrical device.
The foregoing and other objects of the present invention will become more fully apparent from the following description of several preferred embodiments taken with the following drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1A and 1B are schematic illustrations of a confetti launching cannon actuated by the receiver and transmitter of the present invention; and
FIG. 2 is a schematic illustration of a remote control transmitter comprising a further embodiment of the present invention.
DETAILED DESCRIPTION
Referring to FIG. 1, numeral 10 indicates a confetti launching cannon. Such cannons are generally known and comprise a length of tubing, such as PVC tubing, which is filled with confetti, and preferably with FLUTTER FETTI® confetti as described in U.S. Pat. Nos. 5,352,148 and 5,419,731. Compressed air or CO 2 is contained in a high pressure cylinder 12, and the flow of the compressed gas is controlled by an on-off valve 14 operated by a solenoid 16. Thus, when solenoid 16 is actuated by a flow of current, valve 14 is opened and the high pressure gas from cylinder 12 launches the confetti out of the cannon in a large visual display of color and motion.
Such confetti launching systems are frequently located in high and difficult-access places such as, for example, in ceiling rafters, on ceiling-mounted light banks, and on the tops of buildings at amusement parks. As such, it has long been desired to have such systems self-powered and remote controlled. That is, to be operable without running either electric power lines or control circuit wires to such remote locations, and the present invention fulfills this need.
As further shown in FIG. 1, one embodiment of the overall receiver circuitry 20 includes a battery 22 which is connected through a switch, or switching circuit, 24 to supply power to solenoid 16 through leads 25. By way of example, it has been found that a battery of either the alkaline or NiCad type having a voltage in the order of 3 to 12 volts, and preferably 6 volts performs very well in operating solenoid 16 and opening valve 14. Within these preferred voltage ranges, the same battery 22 may also be employed to supply preferred voltages and currents to operate first and second receiver circuits 26 and 28, respectively. As illustrated schematically, battery 22 supplies a voltage to receiver circuit 26 through schematic connection 30, and when activated by a first signal 34 from transmitter 35, as will be further described hereinafter, receiver circuit 26 supplies a voltage through switch, or switching circuit, 32 to receiver circuit 28. However, this voltage to receiver circuit 28 only activates circuit 28 to be "on," or "receptive" to a second, different signal to be received by receiver circuit 28 from transmitter 35. Thus, only when the first signal 34 is received by the first receiver circuit 26 does the second receiver circuit 28 become turned "on" or "receptive." Then, only when second receiver circuit 28 receives the second signal 36, of different frequency and/or wave shape than the first, does second receiver circuit 28 activate switch, or switching circuit, 24 to pass current from battery 22 to solenoid 16 to launch the confetti. In this manner, the receiver circuitry 20 prevents any spurious signal from launching confetti prematurely because, even if such spurious signal matches one or other of predetermined signals 34 or 36, the control system will not supply power to the solenoid. Rather, the solenoid can only be actuated when: (a) receiver circuit 26 is receiving a signal corresponding to signal 34 and, (b) at the same time, receiver circuit 28 is receiving a signal corresponding to signal 36. Thus, both of switches A and B of the transmitter must be turned on in order for the two signals to be generated simultaneously and transmitted to the respective receiver circuits 26 and 28.
As a further safety precaution, it is preferred that transmitter 35 include an on-off power switch 38 so that no signal may be inadvertently transmitted by accidental bumping or pushing of push button or toggle switches A and/or B.
With respect to the first and second signals 34 and 36, the two signals may be signals of substantially different frequencies. Alternatively, the first signal may be a pulsed signal, or of a unique wave shape, or may be a carrier signal with a second signal imposed thereon so as to be as different as possible from other signals used for radio communication and controlling remotely actuated devices. However, even if the two signals only differ as to their frequencies, the chances of two spurious signals existing at the same time, with the two spurious signals matching the two different frequencies of the predetermined signals, is extremely remote.
As previously mentioned, the remote radio control system of the present invention may be utilized to operate other types of special effects such as turning on lights and/or actuating pyrotechnic displays.
A further preferred feature of the present invention is illustrated in FIG. 2 wherein a transmitter 40 for actuating multiple special effects devices is shown. In this embodiment, the transmitter has a power on-off switch 42 corresponding to switch 38, and also has an "ARM" switch 44 corresponding to switch A of the FIG. 1B embodiment. However, instead of a single switch B, the transmitter of the FIG. 2 embodiment has a plurality of switches 46 through 51. Each of the switches 46-51 activates a different tuning circuit whereby closure of each switch transmits a signal of a different frequency, and it will be understood that receiver circuitry 20 includes a plurality of second receiver circuits 28 with each such receiver circuit tuned to receive one of the secondary signals of different frequencies produced by closure of switches 46 to 51. In this manner, the transmitter of the FIG. 2 embodiment includes the same safety features of the previous embodiment in that two separate and different signals must be generated and transmitted simultaneously in order for switching circuit 24 to be turned on. At the same time, one transmitter and one multiple receiver circuit may actuate a plurality of different special effects devices such as, for example, multiple confetti cannons, multiple lights, and/or multiple pyrotechnic displays, and combinations of these and other special effects.
In the foregoing description, the control circuit has been described as being powered by a battery, and this source of power is preferred whenever the installation is to be used only once, or only a few times, or wherever AC power is not readily available. However, if the installation is to be relatively permanent, or where AC power outlets may be available, such as in wired ceilings of many ballrooms, convention centers and theaters, then it will be apparent that AC power may be substituted for battery 22 if desired.
From the foregoing description of several preferred embodiments of the present invention, it will be apparent that numerous variations will be apparent to those skilled in the art of radio transmitting and receiving. Accordingly, it is to be understood that the foregoing description is intended to be illustrative of the principals of the invention, rather than limiting thereof, and that the present invention is not to be limited other than as expressly set forth in the following claims interpreted under the doctrine of equivalents. | A remote control system for actuating special effects theatrical devices is disclosed in which a transmitter generates and transmits two different signals, and a receiver includes first and second receiver circuits such that the first signal arms the receiver but does not actuate the special effects theatrical device unless and until said second signal is also received. | 6 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a divisional application of Ser. No. 14/243,443 filed Apr. 2, 2014; said application Ser. No. 14/243,443 is a continuation-in-part of U.S. patent application Ser. No. 13/777,767 filed Feb. 26, 2013 and issued as U.S. Pat. No. 9,119,382 entitled Portable Basket Colony for Growing and Transport and Method of Use; the entire disclosures of which are incorporated herein by reference.
BACKGROUND OF INVENTION
[0002] 1. Field
[0003] The field relates generally to poultry processing and more particularly to handling, growing and transporting live poultry.
[0004] 2. Background Art
[0005] Loading and unloading birds and transportation of live birds from the hatchery stage through the kill stage at a production facility is a challenging task. The birds have to be gathered, contained and transferred to a transport means and subsequently unloaded with minimal damage or harm to the animal, which is challenging because birds instinctively resist such movement. For example, transport of live poultry from the hatchery to growing houses, and from growing houses to processing facilities is required. One method of transport of live poultry is containing the birds in cages and stacking the cages on a truck with a flatbed trailer for transport. Loading and unloading trailers with live animals, particularly from a location where the animals are grown or raised to a processing facility, can in the case of chickens, increase the stress level of the animal. With heightened stress, animals are more likely to have increased body temperature, experience bruising, dislocated wing/leg joints and potential tissue damage along with an increased pH level, which may affect the quality of the muscle. Once the birds are captured in cages, the cages must be loaded on the trailer.
[0006] Existing systems involve crews of catchers to unload the birds from the growing colonies and load them for transport means. Loading of the cages on the trailer consumes the full time of one operator to move cages from the house or growing area to the trailer and it requires skill to stack cages on the trailer so that they can be properly secured for transport. The cages often become damaged in this operation over time and need to be repaired and eventually replaced. Damage to the cages often involves the doors through which the birds are inserted. Poorly operating doors leads to increased time to load cages and potential bird damage.
[0007] There are significant labor issues because it is very labor intensive and requires some level of skill and training. There are health issues for both the birds and the handlers. The labor intensive handling of the birds promotes infections of the handler and risks harm to the birds. This results in numerous health and safety concerns. The cages are prone for damage which can cause bird damage and extensive time and labor is utilized to fill the cages with birds and load and secure them for transport. The cages or other transport containers also have to be cleaned prior reuse, which can also be a labor intensive and costly effort.
[0008] Loading of poultry is a cumbersome and time consuming task. In the catching process, the poultry are placed into cages. Some cage designs consist of “drawers” and can vary from 10 to 15 drawers averaging a 20-25 bird capacity per drawer. Birds can be placed into the cages either manually or by semi-automatic means. A forklift then can load a flatbed truck with 18-22 cages that are stacked in pairs. Once the cages are in place, each stack has to be secured by chains to the frame of the trailer.
[0009] Semi-automated methods of harvesting the birds in the houses have encountered mechanical and functional problems. In one sense this semi-automated method eliminates the need for operators to physically pick up the birds. However, operators are still needed to operate the equipment and to move the birds forward and away from the sides of the house. Therefore, some handling is still necessary.
[0010] Plastic poultry trays or drawers are sometimes used to transport and house birds temporarily, however, these systems are temporal and only used during certain stages and are not integral with growing systems or transport systems. Use of such trays or drawers still require significant handling of birds, though they may be somewhat more durable than metal cages. Further, these plastic poultry trays, though less often than the standard cages, are also subject to damage or breakage resulting in a need to replace the entire tray, even though only one area of the tray may be cracked or otherwise damaged. The plastic trays are likely easier to clean and sanitize than the standard cage but given the size of the typical plastic tray and the webbing of the mesh, they also can be difficult to clean. Also, storing trays when they are not in use can consume a large amount of space.
[0011] As noted above, problems occur with, loading, unloading, harvesting, placing birds into cages (plastic drawers or trays), loading the cages on a transport, and transporting to the processing facilities. Also, current processes are labor intensive and costly. The problems occur as the DOC (Day Old Chicks) are transitioned from the hatcheries to the growing centers and then to the production facilities. A new system and method for harvesting, loading, growing, transporting, and unloading is needed that addresses the above problems by reducing physical handling of the birds from the hatchery stage through the kill and production stage. In the new system and method, the device by which the birds should be transported should be reusable, interchangeable, and easily cleaned.
BRIEF SUMMARY OF INVENTION
[0012] The technology involves a system and method for handling poultry comprising a colony basket apparatus utilized throughout the process of transitioning the DOC from the hatchery, to the growing facility, through the growing process, and on to the production facility. The colony basket apparatus is utilized for harvesting, loading and unloading, growing, transport, storing and holding through the shackling process prior to the kill process. The method utilizes the colony basket apparatus to perform the steps of retrieving and loading a grouping of the DOC into the colony basket at the hatchery, transporting the same grouping of birds in the same colony basket to the growing facility, loading the colony basket containing the original grouping of birds into the colony system of the growing facility, growing the DOC to Broilers (chickens bred and raised specifically for meat production) in the original colony basket in which they were installed, removing and harvesting live poultry from the colony system while maintaining the same grouping of birds in the same colony basket in which they were originally placed, stacking and loading the colony basket of Broilers on a transport, transporting to a poultry production facility, unloading the colony basket and temporarily storing the poultry in the same colony basket for subsequent killing. The invention more particularly relates to a new portable colony basket for holding and making possible all necessary functions for the poultry animals from the DOC stage, through growing, through transport and up to production while maintaining a grouping of birds or subset thereof in the same colony basket throughout the process all of the way through the shackling process.
[0013] The concept of harvesting poultry utilizing one type of colony basket uniformly throughout the entire process from capturing the DOC at the hatchery to growing houses equipped with colony systems and on to production will make the process more efficient and will result in less worker and animal stress by resolving many of the problems related to the current methods of manually catching birds and placing in cages or other containers or using semi-automated systems to harvest and transition poultry. With the present invention, stackable tray colony baskets can be utilized that can be placed into and retrieved from colony systems in growing houses using automated systems and can be transferred and retrieved from transports when transitioning between locations within the overall process and the colony baskets can be further integrated with feeding and watering systems. The trays can be made from molded plastic or other material including metal aluminum metal and can have an open grid flexible flooring elevated above a lower manure trap flooring to keep the birds out of their manure and the sides can be vented. The bottoms can have an open grid pattern bottom to allow the birds to grasp with their paws to stabilize and reduce wing flapping, but the floor can also be flexible to reduce injury to the bird. The grid pattern also allows debris and feces to fall out to reduce cleaning and increased airflow to ventilate the birds. The top and bottom perimeter edges of the cages can be complimentary in shape for ease of stacking and stability reducing lateral movement of the stacked trays with respect to each other. The sides of the trays can also have vented openings. Once an upper tray is stacked on top of a lower tray, birds placed in the lower tray are contained. The upper most tray in a stack of trays can be capped by an additional empty tray or other cover or ceiling in the colony system or in the transport or other automated transitioning means.
[0014] An empty stack of colony baskets can be transported to a hatchery and loaded with DOC. The stack of colony baskets containing DOC can be loaded on a transport rack, which receives the colony baskets and transported to a growing house from the hatchery. The colony baskets can be unloaded from the transport rack to be transferred into a poultry house colony system manually or the transfer can by automated by a powered mover or conveyor and/or loading system. This method provides that no container stacks have to be manually or mechanically un-stacked for loading poultry because the DOC are already in the colony baskets. Previous systems required that trays be removed from a stack and then the poultry would be loaded into the trays and the trays are re-stacked, a powered mover can transport the trays to the outside to be loaded onto the trailer. The process of loading and unloading birds in the growing house has been eliminated.
[0015] The construction of the trailer can be a flatbed trailer with vertical framework to make up the structural integrity as well as to hold the stacks of individual colony baskets. There can be a plurality of vertical and horizontal rails to insure the structure and flexibility of the size and number of colony baskets the transport is capable of handling.
[0016] With the design of the present invention, there can be a frame work constructed on the transport trailer holding a lightweight material that can be pulled alongside the trailer to cover the sides. This shroud can create an envelope in which the environment can be better controlled and provide a more suitable environment for the animals.
[0017] Once the trailer arrives at the plant, the colony baskets can be unloaded and automatically moved into a warehouse or holding facility. This process can be performed as trucks arrive in order to build an entire storage of birds for a production shift. The trucks can be automatically unloaded in a very short period of time, thus eliminating the need for a forklift. The system can work in a “last-in first-out” method. The process can be improved through the efficiency of bringing the birds in the same colony basket that originated at the hatchery and the same colony basket continuing through the growing process and on to the production plant kill area and not consuming time loading and unloading birds into and out of cages or other containers.
[0018] The automated unloading can be done automatically to pull the trays off the trailer (or flatbed of transport) from the side of the truck in the stacked formation into a transport rack or onto either a conveyor or pull chain system. The transport rack or the conveyor can take the trays to the staging area where they can be un-stacked manually or by using destacker equipment.
[0019] With the proposed method, the colony baskets provide a perfect transport, growing container and housing means all in one unit to move the birds through the entire process. This system can eliminate the unnecessary handling of the birds and possibly make the process more efficient.
[0020] In another implementation of the present technology, a modular colony basket (modular tray) is used for the colony basket apparatus. The modular basket can comprise a floor formed of mesh panels and modular side walls that receive a beam extending through a hinge element connecting mesh panels to the floor. As in the previously described colony basket, the modular basket is stackable with other modular baskets and can have all of the functionality and interfaces as the non-modular implementation. The modularity of the basket allows the basket or tray to be periodically disassembled for routine scheduled cleaning and sanitizing, which would be easier than trying to clean and sanitize the whole basket. Further, if only a small section of a basket/tray is damaged, the modularity provided with this implementation allows a given section to be replaced without disposing of the entire tray.
[0021] There are a number of advantages to the design of the present invention for harvesting poultry. Safety is increased for the handler and the birds and health risks are reduced. The efficiencies of handling and transporting birds is improved and the process is less labor intensive and causes less stress on animals.
[0022] Moreover, because the present invention teaches the use of a modular colony basket, a method is provided wherein the devices used to transport the birds may be easily disassembled and cleaned before being reassembled.
[0023] These and other advantageous features of the present invention will be in part apparent and in part pointed out herein below.
BRIEF DESCRIPTION OF THE DRAWINGS
[0024] For a better understanding of the present invention, reference may be made to the accompanying drawings in which:
[0025] FIG. 1 is a colony basket integrated with a watering and feeding system;
[0026] FIG. 2A is a perspective view illustration of stacked colony baskets;
[0027] FIG. 2B is a side view illustration of stacked colony baskets;
[0028] FIG. 2C is an end view illustration of stacked colony baskets;
[0029] FIG. 3A is an illustration of a colony basket rack;
[0030] FIG. 3B is an illustration of a sectional detail of a colony basket rack;
[0031] FIG. 4A is a colony basket rack;
[0032] FIG. 4B is a side plan view of a colony basket;
[0033] FIG. 4C is a side plan view of a colony basket;
[0034] FIG. 4D is a colony basket rack support;
[0035] FIG. 4E is a colony basket rack conveyor assembly;
[0036] FIG. 5A is a colony basket rack support;
[0037] FIG. 5B is a colony basket rack conveyor assembly;
[0038] FIG. 6 is a flow diagram of the colony basket methodology;
[0039] FIG. 7 is an illustration of the hatchery conveyor, DOC counter and egg shell separator;
[0040] FIG. 8 is an illustration of a colony system;
[0041] FIG. 9 is an illustration of loading colony baskets from a rack to a colony system;
[0042] FIG. 10 is an illustration of the colony system operation;
[0043] FIG. 11 is an illustration of a transport loading system;
[0044] FIGS. 12A, 12B and 12C are an illustration of loading a transport;
[0045] FIGS. 13, 14, 15, 16, 17, 18 and 19 are an illustration of transferring colony basket stacks from a colony system to a trailer;
[0046] FIGS. 20, 21 and 22 are an illustration of retrieving colony basket stacks from a trailer;
[0047] FIGS. 23 and 24 are an illustration of transferring colony baskets to a kill line;
[0048] FIGS. 25 and 26 are an illustration of colony baskets traveling through the kill line and the cleaning station.
[0049] FIG. 27 is a perspective view of an assembled modular poultry raising basket according to the teachings of the present invention;
[0050] FIG. 28 is a top view of the poultry raising basket of FIG. 27 ;
[0051] FIG. 29 is a side view of the poultry raising basket of FIG. 27 ;
[0052] FIG. 30A is a perspective view of a floor panel for the basket of FIG. 27 ;
[0053] FIG. 30B is an alternative perspective view of the floor panel of FIG. 30A ;
[0054] FIG. 30C is a bottom perspective view of the floor panel of FIGS. 30A and 30B .
[0055] FIG. 30D is a front view of the floor panel of FIGS. 30A, 30B, and 30C .
[0056] FIG. 31 is a detailed view of a corner of the floor panel of FIGS. 30A and 30B ;
[0057] FIG. 32 is an exploded perspective view of assembling four floor panels using a beam for the basket of FIG. 27 ;
[0058] FIG. 33 is a detailed view of the intersection of the four floor panels of FIG. 32 ;
[0059] FIG. 34 is a cross-section view of an intersection between two adjacent floor panels using a beam for the basket of FIG. 27 ;
[0060] FIG. 35 is an illustration of a front lower corner of the basket of FIG. 27 ;
[0061] FIG. 36 is an illustration of the side walls of the basket of FIG. 27 ;
[0062] FIGS. 37A, 37B, 37C, 37D, 37E and 37F are various illustrations of a first side panel suitable for forming a side of the basket of FIG. 27 ;
[0063] FIGS. 38A, 38B, 38C, 38D, 38E and 38F illustrate an embodiment of a second side panel configured to mate with the first side panel;
[0064] FIG. 39 illustrates the stacking of two side panels according to an illustrative embodiment of the invention;
[0065] FIG. 40 is an illustration of the inside of two stacked side panels;
[0066] FIG. 41 is an enlarged illustration of region A of FIG. 40 ;
[0067] FIG. 42 is an illustration of the outside of the stacked side panels of FIG. 40 ;
[0068] FIG. 43 is an enlarged illustration of region B of FIG. 42 ;
[0069] FIG. 44 illustrates a stack of modular baskets according to an embodiment of the invention; and
[0070] FIG. 45 illustrates a frame for a poultry colony employing modular baskets according to an embodiment of the invention.
[0071] While the invention is susceptible to various modifications and alternative forms, specific embodiments thereof are shown by way of example in the drawings and will herein be described in detail. It should be understood, however, that the drawings and detailed description presented herein are not intended to limit the invention to the particular embodiment disclosed, but on the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the present invention as defined by the appended claims.
DETAILED DESCRIPTION OF INVENTION
[0072] According to the embodiment(s) of the present invention, various views are illustrated in FIGS. 1-45 and like reference numerals are being used consistently throughout to refer to like and corresponding parts of the invention for all of the various views and figures of the drawing. Also, please note that the first digit(s) of the reference number for a given item or part of the invention should correspond to the Fig. number in which the item or part is first identified.
[0073] One embodiment of the technology is a single colony basket design adapted to be used throughout poultry processing from the hatchery, through growing and to production. The colony basket includes components designed for the growing process and components designed for transport. The colony basket is adapted for an automated loading system including a stackable tray design, a transport system, and unloading and storing system.
[0074] The details of the invention and various embodiments can be better understood by referring to the figures of the drawing.
[0075] Referring to FIG. 1 , a colony basket integrated with a watering and feeding system is shown. The colony basket growing assembly 100 is shown with a colony basket 102 having vented vertically upright side walls 104 and 106 extending between a top rim flange and a bottom rim flange. The vertically upright side walls include vented areas 108 . The top rim flange includes a plurality of stand-offs as represented by items 110 and 111 . The stand-offs can provide spacing between colony baskets when they are stacked one on top of the other. The bottom rim flange can include complimentary recessed receptacles to receive the stand-offs therein in order to interlock the stacked colony baskets and in order to prevent or resist lateral and longitudinal movement. The top rim flange and the adjacent side wall can have vertical slots 116 and 118 for receiving the water channel and water trough assembly 120 and 122 . The colony basket 102 can also be integrated with a feed channel 124 and feed trough 126 . The feed assembly and the watering assembly can be more generally referred to as sustenance assemblies that can be elevated above the basket for basket removal and installation and ultimately lowered into the basket. The parametrical top rim flange defines an upward facing opening through which birds can be inserted into the basket. The downward facing opening is closed by a floor 112 providing support and a trap for debris. The floor 112 can have placed thereon elongated elevator strips 114 over which a flexible mesh flooring (Not Shown) can be supported and installed. The flexible mesh flooring, not shown, can have small openings through which debris can fall downward through the mesh flooring and be trapped by the floor 112 . The flexibility of the mesh flooring prevents injury to birds standing thereon. The colony basket growing assembly 100 is shown in its configuration when it is integrated within a colony system whereby the birds are housed within the colony basket and provided nourishment for the growing process. For another embodiment, the floor 112 can be a mesh floor and the strips 114 can support the mesh floor. A further modification to this embodiment can include an under panel or cover that removably attaches immediately underneath the mesh floor 112 .
[0076] Referring to FIG. 2 , a colony basket stack is shown. In FIGS. 2A-2C various views of a colony basket stack 200 is shown. The colony baskets are shown stacked one on top of the other. The colony basket stack 200 can be transported in this configuration and as seen in the various views, the colony baskets are vertically spaced one with respect to the other by the stand-offs 111 and 110 . The bottom facing rim of the basket above can be configured with a mating receptacle recess for receiving the stand-off of the basket immediately below.
[0077] Referring to FIG. 3 , a colony basket rack is shown. A rack assembly 300 is shown and configured for a colony system. The rack transfer and conveyor assembly 302 is shown which is utilized to support the colony basket as well as transfer the colony basket into and out of the colony racks of the colony system. The colony system configuration is shown with a feed assembly 304 and a watering assembly 306 . The slot 116 shown where the water assembly 306 can be lowered therein. The feed assembly 304 and the water assembly 306 is shown in a lowered position but can be elevated above the colony basket using a wench system adapted to raise and lower the assemblies so that the basket can be inserted and removed from the colony basket rack without being obstructed by the assemblies. Other drawer designs are not adapted such that watering and feeding assemblies can be raised above or lowered into the container.
[0078] Referring to FIGS. 4A through 4E , a colony basket rack is shown, a side plan view of a colony basket is shown, a side plan view of a colony basket is shown, a colony basket rack support is shown and a colony basket rack conveyor assembly is shown. FIGS. 4A-4E show the various components of the rack assembly 300 within the colony system configuration. The colony baskets are longitudinally installed within the rack assembly 300 . The longitudinal installation aligns the vertical slots of the colony baskets to be aligned with the water trough system. The components of the transfer system including the support transfer rack 400 and the rack transfer conveyor assembly 302 is also shown.
[0079] Referring to FIGS. 5A-5B , a colony basket rack support is shown and a colony basket rack conveyor assembly is shown. FIGS. 5A and 5B show further detail of the support transfer rack 400 and the rack transfer conveyor assembly 302 . The rack transfer conveyor assembly 302 includes a conveyor belt 500 and a conveyor roll assembly 502 . The rack transfer conveyor assembly 302 also includes a hydraulic cylinder extension arm 504 that can be utilized to engage the baskets with engagement members 506 and extend to transfer a colony basket stack from one rack to another and/or from one rack to a transport system. The basket cylinder arm and basket retention bar 504 can be actuated to longitudinally extend and retract during retrieval and insertion of a basket. The basket retention bar 504 can include basket engagement members member that engages the basket by applying lateral pressure against the side of the basket and/or engages a complimentary receptor configured to receive the engagement member. The retention bar and engagement member can be rotated about pivot 508 in order to rotate upward to engage a basket or to rotate outward and downward away from the basket. The support transfer rack 400 can support a basket and the support transfer rack can be integral with a rack allowing the transfer rack 400 to elevate or lower the basket with the rack when it is supporting a basket.
[0080] Referring to FIG. 6 a flow diagram of the colony basket methodology is shown. FIG. 6 shows a flow diagram of a circular process utilizing a system of colony baskets throughout the entirety of the process. A given colony basket will retain the same colony (grouping) of birds throughout the process. Initially a colony basket is filled with DOC at a hatchery as reflected by step 600 . Groupings of colony baskets each containing their own individual grouping of birds are then transferred to a growing house (colony farm) 602 where the baskets are loaded into a colony system as reflected by 604 . The birds are retained in the same colony basket in which they were originally installed throughout the growing process and the growing process proceeds as reflected by 606 . The colony baskets are integrated with the watering and feeding systems within the colony system of the growing house. Once the growing process has been completed, the birds are retained in their original colony basket and the baskets are removed from the colony system and transferred to the trailer of a transport as reflected by step 608 . The transport carries the grouping of baskets to a processing plant where the colony baskets are stacked and stored for future processing as reflected by steps 610 and 612 . Again, each of the grouping of birds are retained in their original colony basket throughout the process. The baskets are unloaded as reflected by step 614 and transferred to the kill line as reflected by step 616 or 617 which may be a controlled atmosphere stunning system (CAS) path and there can be separate paths that can be chosen. The birds can be removed from the original baskets in which they were placed and installed on shackles for further processing. The baskets can then be sent through a cleaning process as reflected by step 618 . The cleaned baskets can then be transported to a hatchery 620 and a new batch of DOC can be installed into the baskets and the process can repeat itself.
[0081] Referring to FIG. 7 , an illustration of the hatchery conveyor is shown. FIG. 7 is an illustration of a hatchery system where groupings of DOC 700 can be placed on a conveyor system 702 and transferred into colony baskets by a transfer system 704 and the baskets filled with DOC can then be stacked and transferred to a growing house containing a colony system. The transfer system 704 installs the DOC in a basket and separates the DOC from the shells that remain after the bird hatches.
[0082] Referring to FIG. 8 , an illustration of a colony system is shown. FIG. 8 is an illustration of a colony system where rows of rack assemblies 800 are aligned side-by-side in which colony systems are installed as reflected by Items 800 and 802 respectively. A rack assembly 300 can be utilized for transferring the colony baskets from the rack to the colony system. The colony baskets can be longitudinally installed within the colony system for the growing process. The colony basket stacks 200 can be installed on wheeled platforms for transporting the colony baskets stacks as reflected in the illustration.
[0083] Referring to FIG. 9 , an illustration of loading colony baskets from a rack to a colony system is shown. FIG. 9 is a further illustration of transferring a colony basket stack 900 on a wheeled platform 902 to a colony rack 302 for insertion of the colony baskets into the colony system as reflected by Items 800 and 802 .
[0084] Referring to FIG. 10 , an illustration of the colony system operation is shown. FIG. 10 is an illustration of the growing process in operation whereby workers 1002 utilizing platforms 1004 can tend to the growing process by maintaining the watering and feeding systems. The water and feed assemblies are shown in an elevated position above the basket. When the assemblies are elevated, the baskets can be readily inserted and removed.
[0085] Referring to FIG. 11 , an illustration a transport loading system is shown. FIG. 11 is an illustration of transferring colony baskets 102 from a colony system into a rack assembly 300 for transfer into the transport 1104 having a flatbed 1106 . The colony baskets 102 can be transferred by a transfer conveyor 1102 into a rack assembly 300 . The rack assembly 300 can then be utilized to load the transport 1104 by placing the colony basket stacks on the flatbed of the transport.
[0086] Referring to FIG. 12A-12C , an illustration of loading a transport is shown. FIGS. 12A-12C is a further illustration of transferring colony baskets from the colony system onto a rack assembly for placement on a flatbed of a transport.
[0087] Referring to FIG. 13-19 , an illustration of transferring colony basket stacks from a colony system to a trailer is shown. FIGS. 13-19 provide an illustration of a step-by-step process for transferring colony baskets from the colony system onto the flatbed of a transport. As illustrated, the basket supports 400 are rotated to receive the first colony basket from level 4 . The basket is loaded onto the basket support and a netting material can be installed or draped over the top of the colony basket 102 to retain the birds therein. FIG. 14 illustrates loading a second basket from level 4 and again applying a netting or other covering material over the top of the basket. FIG. 15 illustrates loading a third basket from level 3 and again applying the netting material and draping over the top of the basket. This process is repeated for each of the levels of the colony system as two baskets are loaded from each level and then stacked with the previously loaded baskets.
[0088] FIG. 16 reflects loading the eighth and final basket from level 1 onto the rack transfer conveyor assembly for subsequent stacking of the colony baskets. When a complete stack has been loaded, the basket supports can be rotated outward such that the rack transfer conveyor assembly can begin transferring stacks onto the transport. FIG. 17 illustrates the completed stack and ready for rotating the basket supports outward to ready the loading of the basket stacks onto the transport. FIG. 18 illustrates the rack transfer conveyor assembly conveying the basket stacks onto the flatbed of the transport. FIG. 19 illustrates the completion of the stack loading utilizing the hydraulic cylinder extension arm 1902 for placing and loading the stack onto the flatbed of the transport.
[0089] Referring to FIGS. 20-22 , an illustration of retrieving colony basket stacks from a trailer is shown, which is essentially the reverse of the process for loading a trailer. FIG. 20 is an illustration of subsequently retrieving the basket stacks from the trailer using the hydraulic cylinder arm to engage and pull the stack onto the rack assembly. The hydraulic cylinder arm pulls the stack onto the rack and onto the conveyor for subsequently engaging the support transfer racks for installing and longitudinally inserting the basket into the colony system. FIG. 21 illustrates the beginning of the process for transferring the basket stacks into the colony system. The transfer support racks can be rotated to engage the colony baskets to begin the process of transferring the baskets into the colony system. A reversal of the previous process can be performed by installing two colony baskets per level, beginning with level 1 and moving upward to level 2 , 3 and 4 . FIG. 22 is an illustration of this process.
[0090] Referring to FIGS. 23-24 , illustrations of transferring colony baskets to a kill line are shown. FIG. 23 is an illustration of transferring the colony baskets from the transport to the rack assembly 300 and then transferring the colony baskets onto the colony basket entry conveyor 2302 to convey the colony baskets to the rendering station 2304 . Once the birds have been unloaded from each colony basket, the empty colony basket can then be transferred to the colony basket exit conveyor 2306 . The colony baskets can then proceed through and along the colony basket wash conveyor 2308 which carries the colony baskets through the colony basket washer 2312 . The colony baskets once they are washed can then be reconfigured in a colony basket stack 2310 where the process can be started again.
[0091] FIG. 24 is an illustration of a colony basket entry station 2402 which is another embodiment for transferring the colony basket stacks from the transport to the rendering station.
[0092] Referring to FIGS. 25-26 , an illustration of colony baskets traveling through the kill line and the cleaning station is shown. FIG. 25 is a further illustration of the rendering or kill line whereby workers remove the birds from the colony baskets and hang the birds on the hanging conveyor shackles 2502 .
[0093] The process can begin at the hatchery where a grouping of birds (for example DOC) are gathered and placed into a colony basket. A plurality of baskets can be stacked on over top of another for transport. A netting material can be shrouded over each colony basket to assist in containing the birds. The grouping of birds and their respective colony basket in which they are placed can remain in the same colony basket throughout the process until they are removed as broilers at the kill station. This reduces the handling of the birds to avoid injury and helps to prevent the spread of bacteria or disease between bird groupings. The grouping of DOC can be transported to a growing house in the same colony basket in which they were originally placed at the hatchery, where the poultry are grown for future processing. At the growing location there can be a series of growing colony racks for housing the colony baskets with the original grouping of birds placed therein at the hatchery. At the growing facility, the colony baskets can be integrated with water and feed channels and watering and feed troughs. The colony baskets can have a specific configuration to integrate with the watering and feeding systems as outlined herein in order to assist poultry going through the growth process and assist the operators at the growing facility for attending to the birds. When the poultry have completed the growth process, now in the broiler stage, they can be transported to a location for processing as a final food product. A transport can arrive at the growing location to receive the poultry that have completed the growth process. The transport system can be a truck and trailer combination. The trailer can be a standard flatbed trailer on which colony baskets containing the fully grown poultry can be loaded. The colony baskets containing the original grouping of birds, or some subset thereof, can be transferred from the colony racks of the colony system to the flatbed of the transport. A netting material can be shrouded over each basket before it is stacked in order to assist in retaining the bird. The colony baskets can be stacked one atop another. The transport can be loaded with the fully grown birds and transported along a travel route to an unloading station at a processing facility. The transfer system for transferring the colony baskets from the colony racks to the flatbed can be automated as described herein.
[0094] The unloading station can include an automated unloading system for automatically unloading a colony basket stack from the trailer for storage in an adjacent storage area of the processing facility. Tray stacks can be conveyed to a storage location having a climate controlled storage facility for housing the poultry in the stacked configuration prior to the rendering process. The storage area can be operated on a first in first out system such that a given colony basket stack does not dwell in the storage area for an extended period of time. The storage area can also have a system for controlling and tracking the weight of the tray stacks which could ultimately provide weight information regarding the fully grown poultry.
[0095] Within the storage facility there can be an automated unstacking system for unstacking the colony basket stacks for conveyance through the processing facility. There can be a stunning system utilized including a gaseous environment for stunning the poultry or it can include an electric shock stunning system or a combination of the two. If a gaseous environment stunning system is utilized, the gaseous environment can be a multi-stage stunning system where the first stage(s) can be a combined induction phase and the second stage(s) can be the combined stunning phase. This system can generally be referred to as a controlled atmosphere stunning system or CAS. Once the colony baskets containing the original grouping of birds/poultry have transitioned through the stunning system, the poultry can be unloaded from the trays at an unloading station. The unloading station can comprise an automated unloading system which is operable to tilt the colony baskets sufficiently to remove the stunned poultry from the colony baskets. This is the first point in the process that the birds are removed since their original placement into the colony basket at the hatchery as DOC. Once removed from the colony baskets, the stunned poultry can be conveyed to a shackling station where the poultry can be hung from a shackle conveyor for being conveyed to a plant evisceration facility.
[0096] As described the colony baskets can be stackable. Further the colony basket can have an interwoven wire mesh elevated floor above the colony basket bottom floor where the mesh openings are sufficiently large for debris to pass therethrough and also providing a means for the bird to grasp hold in order to stabilize itself and the mesh floor can be flexible in order to avoid injury to the birds. The frame of the colony baskets include various portions including perimeter top and bottom rim flanges and upright vented side walls. The upward facing surface portion of the upper perimeter top rim flange can be designed to be complimentary with respect to the downward facing portion of the bottom perimeter rim flange. This complimentary configuration can be designed such that the trays interlock when they are stacked thereby resisting longitudinal and latitudinal movement of the trays with respect to each other.
[0097] The stackable tray can be constructed having a top rim flange and a bottom rim flange, which defines the longitudinal and latitudinal dimensions of the tray. The top and bottom rim flanges can have L-shaped cross sections. The inner perimeter of the top rim flange can define an upper opening or upward facing opening through which birds can be easily inserted. The bottom rim flange defines the perimeter of the lower or downward facing opening closed off by the solid floor. The solid floor can have elevators for elevating the mesh floor proximately above the solid floor. The mesh flooring is designed with vented openings where the openings are sufficiently large to allow debris to pass there through. The flexible mesh floor design provides for a surface that can be grasped by the talons of a bird without injury. Upright side walls can be attached around the perimeter of the tray and attached to support members. The inner perimeters of the top rim flange and the bottom rim flange, which define the upper and lower openings respectively, can have substantially the same geometry.
[0098] The top rim flange can include stabilization standoffs which can extend vertically. The top rim flange can have on an upper surface a vertical standoff. The flange and the complementing recessed receptacle on the underside of the colony basket when engaged, one with respect to the other in a stackable fashion, they can resist longitudinal and latitudinal shifting of trays, one with respect to the other. Also, the stabilization standoffs can be placed along the latitudinal and longitudinal sides of the top rim flange. The spacing between the longitudinal, the latitudinal, and the corner upright support ribs define the vented openings of the tray. The spacing between the support members and the height of the support members can be optimized depending on the type of bird being contained within the stackable trays.
[0099] For stacked colony baskets the uppermost colony basket can have a top cover or a netting installed of the uppermost colony basket. The top cover can have a mesh screen for covering the opening of the uppermost tray. The perimeter of the mesh screen can be defined by the top cover flange. The top cover flange can have recessed receptacles for interfacing with the raised standoffs of the uppermost tray.
[0100] The colony basket stacks can be transitioned to the transport and loaded on the flatbed by way of a transfer rack or loading dock or other means for loading the colony basket stacks. Vertically protruding standoffs can be provided on the flatbed for and dimensioned to be received by the recessed receptacles of the lower most colony basket in a stack. The transport can have a shroud covering for better controlling the environmental exposure of the poultry. The shroud covering can be supported by transport side rails. One or both of the side panels of the shroud covering can be a retractable curtain for exposing the flatbed from either side. The shroud covering can also have a rear transport cover opening and or a side transport cover opening through which colony baskets can be loaded.
[0101] The stacked colony baskets can be loaded through the transport cover opening by sliding them along tray tracks which extend along the flatbed. The trailer can be a standard trailer; however, the trailer can have side railings for supporting shroud covering. The top surface of the flatbed can have raised standoffs that conform to the recessed receptacles on the underside of the tray to restrict lateral sliding or movement of the bottom most tray.
[0102] The technology described above includes an additional embodiment. In the additional embodiment, the colony baskets described herein above are replaced with modular baskets. The modular baskets may be utilized and integrated interchangeably with the invention described above.
[0103] FIGS. 27, 28 and 29 illustrate an implementation of a modular basket 2710 suitable for raising poultry or other animals and-or for transporting a product. The illustrative basket 2710 is a modular plastic basket formed of a plurality of interlocking plastic panels. The panels can be formed by injection molding, though other suitable materials and processes may be used to form the panels. In one embodiment, the panels are made of polypropylene and are connected using stainless steel beams. The modular basket 2710 is interchangeable with colony baskets 102 in the invention described herein above and can be fully integrated with other colony baskets in the overall system including integrating with the watering and feeding systems.
[0104] Each basket 2710 comprises a floor formed by an array of interconnected molded plastic floor panels 2720 . The floor comprises a plurality of corner panels, edge panels and middle panels. Each floor panel can be formed as a flexible mesh panel for allowing animal waste and other debris to drop through while providing a comfortable surface for poultry. In the illustrative embodiment, each floor panels 2720 are identical and formed from the same mold, though the invention is not so limited.
[0105] Interconnected side panels 2750 are connected to the floor panels 2720 to form side walls for the basket 2710 . As described below, the side panels receive beams that connect the floor panels to each other to connect the side panels to the floor. The side panels have pliable mesh of expanding size. As also described below, the basket 2710 comprises side panels having at least two different, but similar configurations.
[0106] The basket 2710 has an open top, though the invention is not so limited, and when the sides are assembled, recesses 2751 can be formed to receive watering and feeding systems.
[0107] The basket 2710 is stackable with one or more other baskets to form a vertical, space-saving stack of apartments. Multiple stacks may be arranged within a frame, or arranged side-by-side to form a colony.
[0108] The basket as illustrated comprises twenty-five floor panels 2720 and fourteen side panels 2750 , though one skilled in the art will recognize that any suitable number and arrangement of panels may be used to form a basket of any suitable size, shape and configuration.
[0109] In one embodiment, each floor panel can be between about approximately fifteen and about approximately twenty inches, and one implementation can be between about eighteen and about nineteen inches, by between about approximately twelve and about approximately fifteen inches, and in one implementation can be between about approximately thirteen and about approximately fourteen inches. The side panels have a height between about approximately eight and about approximately twelve inches, and one implementation can be about ten inches and a length between about approximately twenty inches and about approximately twenty five inches.
[0110] The basket 2710 as illustrated and described may hold about ten lbs per square foot. The number of birds each basket holds depends on the intended slaughter weight of the bird. In one implementation, the basket 2710 may hold about 90 six pound birds, about 140 four pound birds or about 209 2.2 pound birds.
[0111] FIGS. 30A, 30B, 30C, and 30D illustrate a single floor panel 2720 suitable for forming a floor, or a portion of a floor, of a modular basket 2710 . FIG. 31 is a detailed view of a corner of the floor panel 2720 . Each floor panel comprises a flexible mesh floor 3022 extending between edges 3024 , 3025 , 3026 and 3027 . A front support beam 3028 extends below edge 3024 and a rear support beam 3029 extends below edge 3025 . The strands forming the mesh 3022 preferably have rounded tops to facilitate run off. In one implementation, the strands have a circular cross-section that is between about 0.100″ and about 0.140′ in diameter. The illustrative strands form square openings 3123 that are between about 0.375″ and about 0.615″ across, though the invention is not limited to the illustrative size and shape. The flexible mesh floor preferably has a certain flexibility to promote comfort and cleanliness. In one embodiment, the flexible mesh floor deflects about 0.5 inches at size pounds of weight in the center. The flexible floor may be more comfortable for the animals. In addition, the flexing may contribute to dried manure cracking off without requiring additional cleaning.
[0112] The edges slope downwards to create a bowl channeling debris through the mesh openings 3023 . As shown in FIGS. 30A, 30B, and 31 , the corners of each floor panel 2720 form downward sloping ramps 3041 for channeling debris through the mesh openings. The illustrative ramps 3041 are triangular in shape and widen from the top to the bottom.
[0113] The center of the floor panel 2720 may be solid for injection molding purposes.
[0114] The floor panels 2720 include hinge elements 3032 , 3033 , 3034 , 3035 extending below the mesh floor 3022 from each end of edges 3026 and 3027 . A first pair of hinge elements 3032 , 3033 extends down from edge 3026 , and a second pair of hinge elements 3034 , 3035 extends down from edge 3027 . The second pair of hinge elements is offset from the first pair. As shown, hinge 3033 is positioned at a corner of the generally rectangular floor panel, whereas hinge 3032 is offset from the corner of the floor panel thereby allowing hinge 3034 of an interfacing abutting floor panel to be position adjacent hinge 3032 and aligned such that beam 3280 may be inserted through the hinge openings. Similarly, on the opposing side of the floor panel, hinge 3034 is positioned at the corner of the floor panel and hinge 3035 is positioned such that it is offset from the corner of the floor panel. Therefore, hinges 3033 and 3034 at diagonally opposing corners of the floor panel are positioned at the corner and hinges 3032 and 3035 are offset from the corner. FIGS. 32 and 33 illustrate the connection of a plurality of the floor panels 2720 using a beam 3280 . As shown in FIGS. 32 and 33 , the hinges 3032 , 3033 , 3034 and 3035 receive a beam 3280 for linking the floor panels together. The illustrative hinge elements include sloped upper surfaces 3036 , flat sides and flat bottoms, though the invention is not so limited. Each hinge element includes a hinge opening 3039 for receiving the beam 3280 . The illustrative hinge openings 3039 are bone shaped to ease beam insertion and facilitate manufacturability. The illustrative beam 3280 has a rectangular cross-section, but the invention is not so limited.
[0115] As shown in FIGS. 32 and 33 , a beam 3280 may be used to join two columns of floor panels to form a floor of a basket, such as the basket 2710 of FIG. 27 . The illustrative basket 2710 of FIG. 27 has five columns of floor panels 2720 in five rows, connected using six beams 3280 , though the basket may comprise any suitable number of floor panels in any suitable arrangement. In addition, the floor may comprise multiple beams 3280 per column. FIGS. 32 and 33 show four floor panels 2720 a , 2720 b , 2720 c , 2720 d joined together by aligning the hinge elements 3034 and 3035 of the left floor panels 2720 a , 2720 b with the hinge elements 3032 , 3033 of the right floor panels 2720 c , 2720 d and inserting a beam 3280 through the aligned hinge elements.
[0116] As clearly illustrated in FIG. 30C , the front hinge elements 3032 and 3034 of each floor panel are offset from each other, so that the hinge element 3032 of a right floor panel 2720 c or 2720 d is adjacent to and behind the hinge element 3034 of a left floor panel 2720 a or 2720 b when the floor panels are joined. The hinge element 3032 is spaced from the front edge 3024 of the floor panel by a distance that is equal to or greater than the width of the hinge element 3034 along the length of edge 3026 , so that the corresponding hinge element 3034 fits between the front of the floor panel and the hinge element 3032 . The rear hinge elements 3033 , 3035 are also offset from each other to allow alignment of the hinges when the edges of the floor panels are brought together. The hinge elements of mating floor panels may abut each other or be spaced apart when joined. The floor panels may have more or fewer hinge elements that interlace.
[0117] As shown in FIGS. 30A-34 , each of the edges 3024 , 3025 , 3026 and 3027 includes lips 3044 that protrude from the edges. The lip 3044 in one implementation extend along a portion of an edge and is offset to one end of the edge. The lip 3044 is offset to one end of 3025, whereas the lip 3044 is offset to an opposing end of edge 3024 . Edges 3024 , 3025 , 3026 and 3027 also slope downwards to promote debris channeling through the mesh 3022 . Edges 3026 and 3027 are complementary, and edges 3024 and 3025 are complementary, so that the lips of one edge, such as edge 3027 , fit in recesses between lips of a mating edge, such as edge 3026 , as shown in FIG. 30 . The shaped edges ensure that there is no seam over the beam 3280 to promote cleanliness. The overlapping edges ensure that the seams between the adjoined floor panels remain covered even as the weight of the animals increases and flexes the floor panels. In addition, the edges 3024 , 3025 , 3026 and 3027 extend inwards past the beam 3280 by a selected amount to promote the channeling of debris through the mesh 3022 and prevent soiling of the beam 3280 . Thus, the outside edges of the floor 3022 are solid to protect the beam 3280 . For example, in the embodiment shown in FIG. 34 the distance D between the front of the beam 8320 and the interface between the edge 3027 and mesh 3022 is at least 0.25″ and preferably at least 0.5″. Lip 3044 extends over edge 3026 as illustrated in FIG. 34 so that the seam is sealed.
[0118] The side panels 2750 connect to the floor using the beams 3280 . FIG. 35 is a detailed view of area 3 of FIG. 29 , showing the connection between a beam 3280 and a side panel 2750 forming a side wall of the basket 2710 . The beam 3280 that passes through and joins adjacent columns of floor panels passes into an opening 3552 in the side panel. The opening 3552 includes recesses to allow twisting of the beam end to lock the beam into place. In the illustrative embodiment, each beam 3280 linking two columns of floor panels passes into an opening in a side panel, but not all side panels receive beams. The edge beams 3280 extend through the hinges of the floor panels along each opposing end forming the short side of the basket floor and the edge beam also extends through the hooks 3769 of each side panel extending along the short side of the basket and these edge beams 3280 extend into the opening 3552 of a side panel 2750 b extending along a long side of a basket and adjacent a corner.
[0119] The side panels 2750 are connected together to form the side walls of the basket 2710 . In the illustrative embodiment, each side panel includes links along the first side and second side edges for connecting the side panel to an adjacent side panel. The links are configured such that the side panels may be connected at either 90° or 180°, as shown in FIG. 36 to form a corner of a side wall. Items 2750 a and 2750 b can be configured at a 90 degree angle to form a corner portion of the side wall.
[0120] The illustrative basket comprises four different configurations of side panels, each with similar features, as described below.
[0121] FIGS. 37A-37F are various views of a first side panel 2750 a suitable for forming a side of a modular basket. The illustrative side panels 2750 a are used adjacent to diagonally opposite corners on the short side of the basket 2710 of FIG. 27 . Each side panel comprises a mesh wall formed between upper, lower and side edges. Each side panel 2750 includes female links 3762 on a first side and male links 3772 on an opposite side. The female links each comprise a protrusion 3763 extending from the side edge. The protrusion forming the female link includes two intersecting recesses 3764 , 3765 . The recesses 3764 and 3765 are perpendicular and have a square-shaped cross-section. The male links 3772 comprise protrusions 3773 aligned with spaces 3766 between the female protrusions. Rods 3775 extend between the protrusions. The illustrative rods 3775 have a square cross-section, with a thicker upper portion and a thinner lower portion. The female links 3762 receive the male links 3772 at either a 90° or 180° to connect two side panels together. As shown in FIG. 36 , a u-shaped pin 3679 may be inserted into a space between the female protrusions 3763 and male protrusions 3773 to hold the links in place.
[0122] The side panels 2750 a further include hooks 3769 extending from the bottom edge for receiving edge beams 3280 that connect floor panels together.
[0123] The side panels 2750 a further include a cavity, illustrated as recess 3781 , formed in the top edge for allowing the passage of feeding tubes or pipes. As illustrated, these side panels 2750 a can be positioned to extend along the short side wall of the basket adjacent the corner of the basket.
[0124] An inside ledge 3791 extends between the links 3762 , 3772 above the beam openings 3552 . The ledge 3791 slopes downwards and overlaps the floor panels 2720 when the basket is assembled to promote cleanliness. Even when the floor panels bow under the weight of animals in the basket, the overlap between the inside ledges 3791 and floor panel edges prevent separation between the components.
[0125] Above the ledge 3791 , the space between the edges of the panels forms an expanding mesh 3793 . The openings 3795 in the mesh 3793 grow larger the higher they are to accommodate growing poultry. In one implementation, the openings are between about approximately one and about approximately three inches wide, where in one implementation the openings are about approximately 2.2 inches and between about one and about approximately two inches tall, preferably about approximately 1.5 inches tall.
[0126] The side panel 2750 a further includes openings 3797 below the ledge 3791 to promote airflow. The side panels used in the opposite corners from the side panels 2750 a are substantially similar, except for the length of the inside ledge 3791 .
[0127] FIGS. 38A-38F illustrate an embodiment of a second side panel 2750 b configured to mate with the first side panel 2750 a . A second side panel 2750 b is disposed between two first side panels 2750 a on the short side of the basket 2710 of FIG. 27 , and a series (four, in the illustrative embodiment) of second side panels are connected at 180° angles along the long side of the basket 2710 . The second side panel 2750 b includes the same female and male links, mesh, ledge, hooks and openings and further includes a stacking tip 3851 extending upwards from the top edge. The bottom edge includes a recess 3861 for receiving the stacking tip of a side panel in a basket below. For the long side of the basket, the second side panel 2750 b has a minimal inside ledge 3791 .
[0128] FIGS. 39-43 further illustrate the means by which side panels 2750 b of baskets 2710 stacked on top of one another engage one another. As illustrated, stacking tip 3851 includes a pyramid-shaped protrusion 3852 having a flat front face 4153 and two straight protrusions 3854 , 3855 opposing the pyramid-shaped protrusion for gripping the bottom edge of an overhead panel. When stacked, the stacking tip allows for a space 4070 to be formed between the overhead and below baskets.
[0129] FIG. 44 illustrates a stack 4400 of nine modular baskets 2710 . Multiple baskets may be stacked together for transportation as described in the previous embodiment. The baskets are self-stacking and stabilized on top of each other.
[0130] FIG. 45 illustrates a frame 4500 for a chicken colony employing modular baskets. The frame includes multiple levels, each level housing a row or more of modular baskets. A conveyor belt may be used to convey the modular baskets 2710 on and off of the frame as described in the previous embodiment.
[0131] The illustrative modular plastic basket provides a comfortable, sanitary, accessible environment with optimal air flow and ventilation for raising chickens or other products. The modular plastic baskets are easily assembled and stackable to save space.
[0132] Poultry can be raised in the basket from the beginning to the end of life. The basket may be easily removed from a poultry house and trucked to a process facility, where it is unloaded, cleaned, then sent back to a hatchery or poultry house.
[0133] The various poultry handling examples shown above illustrate a novel system and method for handling poultry. A user of the present invention may choose any of the above chicken handling embodiments, or an equivalent thereof, depending upon the desired application. In this regard, it is recognized that various forms of the subject chicken handling could be utilized without departing from the spirit and scope of the present invention.
[0134] As is evident from the foregoing description, certain aspects of the present invention are not limited by the particular details of the examples illustrated herein, and it is therefore contemplated that other modifications and applications, or equivalents thereof, will occur to those skilled in the art. It is accordingly intended that the claims shall cover all such modifications and applications that do not depart from the spirit and scope of the present invention.
[0135] Other aspects, objects and advantages of the present invention can be obtained from a study of the drawings, the disclosure and the appended claims. | A colony basket and method of using the same for handling poultry from DOC through the growing process and on to a production facility comprising a harvesting system, a loading system, a transport system, an unloading and storing system, hanging system and cleaning system. The system and method performs the steps of harvesting and colonizing live poultry into a singly stackable and transportable colony basket, stacking and loading the trays on a transport, unloading and temporarily storing the poultry for subsequent processing. The system and method further includes the use of a modular colony basket for interchangeable use with the described system. | 0 |
This is a divisional of application Ser. No. 08/547,472, filed Oct. 24, 1995 Now U.S. Pat. No. 5,626,442.
BACKGROUND OF THE INVENTION
Underground service pipes such as sewers which make up the utility infrastructure need replacement or rehabilitation as they age. Through normal service the lines, typically made of concrete, deteriorate or break allowing waste to escape. The buried pipes present access problems. Also, it is desirable to maintain sewer service while the replacement or rehabilitation of the sewer line takes place.
Repairing a service line can involve digging up most or all of the line and replacing the pipe. This is costly, labor intensive and disrupts normal service. Alternative methods such as pipe bursting have been developed which includes breaking up the old pipe underground and following the bursting operation with placement of new pipe in the space provided. Another alternative method involved extracting the old pipe at intervals and replacing it with new pipe by forcing the new pipe into the space provided after the extraction process. The old pipe that was extracted needed to be disposed of adding another economic factor to the method. Some of these methods utilized pipe jacking machines with hydraulic rams or mechanical drivers to push the new pipe in place. In some cases the pipe jacking equipment took up space in the excavation next to the pipe to be burst or extracted. The access thorough existing manholes was insufficient to accommodate the pipe jacking equipment.
The renewal or rehabilitation of the service lines without digging up the line was developed by inserting new pipe or slip lining with materials such as plastic pipe liners inside the old pipe. Rehabilitation of old pipe with a new internal slip lining requires cleaning the existing host pipe of debris that has built up with use. Some methods utilize stationary derricks for the cleaning operations with a drag bucket. The derricks need to be reset after each operation. The bucket size may be limited by the height of the derrick used to hoist the bucket to the surface. The pipe liner is pushed into the host pipe. Often the pressure exerted in the pushing operation is not evenly distributed causing damage to the liners.
The host pipe should be tested after the cleaning process to determine if debris has been removed and the pipe liner can fit. The new joints of liner pipe is then placed in the host pipe. The liner generally has a slightly smaller diameter than the inside of the host pipe.
SUMMARY OF THE INVENTION
This invention is a system for rehabilitating pipe such as sewer lines which renews the existing service lines without disrupting the flow through the lines. In this description the pipe may be described as a sewer line that is in need of rehabilitation. The system retains the host pipe and therefore the value of the structure in place while not creating additional waste disposal concerns with the extracted pipe. The system utilizes mobile equipment such as conventional excavators that are fitted with winches on the attachment points for custom tools, the winch manipulates and lifts the buckets for the cleaning operation, and the test mandrel and the pipe liner in the slip lining renewal operation.
The system for cleaning the sewer line is often needed prior to the slip lining process because of the debris built up in the sewer line after years of use or rapid deposition of debris because of adverse environment conditions. The present invention utilizes equipment that can be used for both the cleaning and relining process as well as testing the host pipe prior to relining to confirm that the interior of the host pipe is clear and the liner pipe will be received without damage.
In the rehabilitating system of the invention the length of host pipe is accessed on both ends. Manholes already present can be used as access on at least one end of the host pipe and are generally large enough for one end of the operation. A larger excavation to accept the new pipe liner and a test mandrel is required on the other end of the host pipe from the manhole.
In an embodiment of the system the host pipe is accessed through a shaft that can be an existing manhole. A down hole boom is inserted into the shaft. The down hole boom has a winch mounted and a guide roller mounted thereon. The guide roller is adjustably mounted so that when the down hole boom is placed in the shaft the guide roller is positioned to guide the cable from the winch over the roller into the host pipe. The down hole boom generally extends above the surface of the shaft. The winch is preferably mounted on the part of the boom above the surface. In one embodiment the winch on the down hole boom is also mounted to a mobile vehicle such as an excavator.
A selected length from the access shaft another access area to the host pipe is provided that is large enough to accommodate other equipment necessary for the rehabilitation process such as lengths of the new pipe liner. A host vehicle with a movable boom such as an excavator is positioned at the surface of the second access area. Various embodiments of the system use conventional excavators which are easily transported from site to site. A second winch is mounted on the end of the boom. The boom operator can manipulate the boom and winch so that the winch can be moved from above the surface into the access area and to the mouth of the host pipe. In the preferred embodiment, a housing is mounted to the end of the boom and surrounds the winch. The housing protects the winch, but allows for free movement of the cable spooled on the winch. The winch housing is attached to the boom on the custom attachment points used for other types of tools. The cables from both winches are capable of disengageable attachment to equipment used to rehabilitate the host pipe.
One of the pieces of equipment used to rehabilitate the host pipe which is part of the system is a cleaning bucket. The semicircular cleaning bucket is sized to be received in the host pipe. The cleaning bucket has a leading edge with a flap door that is generally semicircular and hinged to the top of one end of the bucket. The flap door swings to the inside of the bucket from the closed to open position. An open end is opposite to the flap door on the cleaning bucket. The cleaning bucket has points of attachment for to the cables such as yokes.
An additional piece of equipment of the system is a test mandrel used to determine if there are any obstructions in the host pipe prior to lining. The test mandrel is a cylindrical member with beveled edges on both ends. A plurality of internal ribs and internal pulling yokes are disposed inside the cylindrical member.
Another feature of the system is a pulling mandrel designed to distribute the pulling forces in an even manner around the pipe liner while it is pulled by the cable on a winch and pulled inside the host pipe. The mandrel also provides for areas of flow therethrough so the sewer remains in service during the slip lining operation. The pulling mandrel is a circular member with a diameter sized to be received into the host pipe and to contact the circumference of a liner for the host pipe. A plurality of spokes extend from the circular member and converge to the middle of the circular member to a central hub. The hub has an opening of sufficient size to accompany a cable passing therethrough.
The invention also includes methods for using the system in rehabilitating the sewer lines. The cleaning method starts with the selected length of host pipe described above that has at least two access points with one access that can be a manhole. The cleaning bucket described above is attached to a cable. In an embodiment one cable is strung between the two winches with the cleaning bucket attached. In a preferred embodiment of the system the cable from the winch on the down hole boom attached to a yoke on the leading edge of the cleaning bucket and the cable on the movable boom is attached to the open end of the cleaning bucket.
The cleaning bucket is lowered into the access area serviced by the winch on the movable mount. The cleaning bucket is pulled by spooling the winch on the down hole boom through the host pipe with the leading edge first so that the flap door is open. The drag is reversed by spooling the winch on the movable mount so that when the cleaning bucket is pulled in the opposite direction the flap door closes and traps debris. The cleaning bucket with the debris is hoisted to the surface by spooling the winch on the movable mount and raising the mount. The debris is discharged from the bucket. The processes is repeated until the host pipe is cleaned.
Generally the next method used in sewer rehabilitation that utilizes the system is a testing procedure to determine that the pipe liner will fit suitably in the host pipe. This operation involves pulling a test mandrel which is a tubular member with the approximate diameter and length of the pipe liner through the host pipe. In the preferred system, the test mandrel has beveled edges on each end and performs a final sweep of the host pipe loosening and removing any remaining solids or mineral deposition on the inside of the host pipe. Also, the internal ribbing provide weirs for collection of the debris. The method for using the system for testing includes lowering the test mandrel in the access area next to the host pipe. The cables from both winches are attached to the internal yokes inside the test mandrel. The winch on the down hole boom is spooled so that the mandrel travels through the host pipe toward the access shaft. The travel is then reversed by spooling the winch on the movable mount. The ease of travel by the mandrel through the host pipe is indicative of an obstruction or lack thereof.
The host pipe is lined after the cleaning and testing process. However lining might be necessary if there has been some structural damage to the integrity of the sewer pipe and a cleaning process is not necessary. At one access area the excavation is large enough to accommodate a length of pipe liner. The same system is used in the cleaning and testing operation may be used in relining the host pipe. A cable on the winch on the down hole boom is passed through the length of the host pipe. The cable is then passed through a length of pipe liner and the pulling mandrel that is placed adjacent to the pipe liner that has also been lowered into the access area.
The cable is secured to the pulling mandrel so that when the cable on the down hole boom is spooled it pulls the pipe liner into the host pipe. The cable is spooled approximately the length of the pipe liner section. The end of the cable is released from the pulling mandrel. Another section of pipe liner is placed in the access area at trailing end of the first pipe liner section and the pulling mandrel is placed at the end of the second pipe liner section. The cable is spooled and the next section of the pipe liner is pulled into the host pipe. This process is repeated until the host pipe length is lined.
Another method of the invention is a method for rehabilitating a host pipe that is adaptable to smaller pipe and can be performed while the sewer is in service. The alternate method is suitable for remote or difficult to access areas. This alternate method uses basically the same equipment for all the rehabilitation work to clean and line the pipe. The alternate method involves selecting the host pipe and accessing two ends through shafts that can be existing manholes. An excavation intermediate to the two shafts is dug and a portion of the host pipe is removed. Two down hole booms are inserted into the access shafts and extend above the surface. Winches are positioned adjacent to the down hole booms. The cable spooled on the winches are placed over guide rollers on the down hole booms so that the winches can pull the cable down the access shaft into the host pipe to the intermediate access area. The alternative method includes down hole booms and winches that can be skid mounted or mobile mounted.
A hoist device with at least one cable is placed at the surface of the intermediate access area to the host pipe. A cleaning bucket as described above is lowered into the intermediate access area by the hoist and attached to one of the cables associated with the winch and down hole boom. Cables from the winches on the down hole booms are attached to either end of the cleaning bucket. As the cleaning bucket is pulled through the host pipe and reversed the debris is trapped. The cable on the hoist is attached to the cleaning bucket. The cleaning bucket is withdrawn from the intermediate access area and the collected debris is discharged at the surface. With two access shafts to the host pipe, the cleaning bucket can used on both sections of the host pipe extending from the intermediate access area.
The testing method utilizes the same equipment. A test mandrel is lowered into the intermediate access area by the hoist. Cables from the two winches are attached to either end of the test mandrel and it is pulled through the host pipe to determine if any obstruction exists.
The same equipment is used to line the host pipe. The hoist introduces pipe liner into the intermediate excavation area. Both sections of host pipe that extend from the intermediate access area are lined. A cable extended from one of the winches into the intermediate access area is passed through a section of pipe liner and then secured to a pulling mandrel. The cable is spooled approximately the length of the pipe liner. The pulling mandrel is removed and another section of pipe liner is introduced into the intermediate access area by the hoist and aligned to abut with the first section pulled into the host pipe. The cable is released by the winch and pulled through the second section of pipe liner and secured to the pulling mandrel. The winch spools the cable pulling the first and second sections of pipe liner into the host pipe. The process is repeated using both winches until the host pipe extending from the intermediate area is lined.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic depiction of the sewer rehabilitation system during the cleaning process.
FIG. 2 is a schematic depiction of the sewer rehabilitation system during the testing process.
FIG. 3 is a schematic depiction of the sewer rehabilitation system during the host pipe lining process.
FIG. 4 is a schematic depiction of an alternative embodiment of the sewer rehabilitation system showing the cleaning process of the sewer line.
FIG. 5 is a alternative embodiment of a sewer rehabilitation system showing the testing of the sewer line.
FIG. 6 is a schematic depiction of an alternate system showing the host-pipe lining operation.
FIG. 7 is a perspective view of a cleaning bucket.
FIG. 8 is an end view of the cleaning bucket with the flap door closed.
FIG. 9 is a side view of the cleaning bucket showing the swing of the flap door.
FIGS. 10a, 10b and 10c are perspective views of the cleaning bucket and winch during the discharge process.
FIG. 11 is a perspective view of the pulling mandrel.
FIG. 12 is a perspective view of the pulling mandrel and direction of pipe liner.
FIG. 13 is an exploded view of the pulling mandrel with the locking teacup, cable and pipe liner.
FIG. 14 is a side view of the exploded depiction of the locking teacup, pulling mandrel, pipe liner and cable.
FIG. 15 is a partially perspective view of the test mandrel that also shows the internal ribs and yokes by the dotted lines.
FIG. 16 is a cross-section at line 16 of FIG. 15.
FIG. 17 is a perspective view of the winch and housing.
FIG. 18 is a side view of the winch and housing.
FIG. 19 is a down hole boom with two adjustable guide rollers for use in an alternative embodiment of this system.
FIG. 20 is an alternative embodiment of a down hole boom with two adjustable guide rollers for use in an alternative embodiment of this system.
FIG. 21 is a perspective view of a down hole boom and winch associated with a movable mount.
DETAILED DESCRIPTION OF THE INVENTION
A system for rehabilitating sewer lines is shown in FIG. 1 during cleaning of a host pipe. As shown in FIG. 1, the host pipe 10 has been accessed at one end of the selected length for rehabilitation by access shaft 12 which can be an existing manhole or other existing access shaft to the sewer line which is wide enough to accommodate down hole boom 14. Down hole boom 14, as shown in FIG. 1, extends from above the surface of the manhole entrance to the bottom of the manhole and rests on the bottom of the manhole. In the preferred embodiment down hole boom has a guide roller 16 at the end of the down hole boom close to the mouth of the host pipe. The guide roller is adjustable along the length of the boom so that cable 18 from winch 20 can extend into the access shaft along the down hole boom around guide roller 16 and into the host pipe. Depending on the diameter of the host pipe, guide roller 16 can be adjusted on the down hole roller so that the cable 18 extends preferably to the host pipe. Auxiliary guide roller 13 mounted on the down hole boom 14 is also shown. The extension of the down hole boom may be adjusted by attaching different lengths together. A joinder point 15 is shown on the down hole boom 14 where two lengths are fastened together. Winch 20 is mounted on the part of the down hole boom extending above the manhole. However the winch could be located beneath the surface in the manhole. Winch 20 is also mounted to a host vehicle 22 which in FIG. 1 is shown as a conventional excavator. However, down hole boom 14 and winch 20 may be supported at the surface above access shaft 12 by a stationary support. FIG. 1 illustrates the use of a host vehicle 22 to illustrate the transportability of the system.
The winch 20 spools and pulls cable 18. The winch may be mechanically driven, but in the preferred system the winch mechanism is hydraulically driven and operated. Cable 18, threaded on winch 20, extends the length of down hole boom 14 may be guided on the down hole boom by additional guide rollers, such as auxiliary guide roller 13 then around guide roller 16 at the mouth of host pipe 10 and into the host pipe. In FIG. 1 the cleaning bucket 26 is attached to cable 18 at yoke 28.
A second access area generally indicated by reference numeral 30 is excavated a selected length from access shaft 12. The second access area extends from the ground surface and a portion of host pipe 10 is removed. As shown in FIG. 1 a system of this invention can be used while the sewer is flowing and the host pipe was removed down to the spring line to contain the sewer effluent. Adjacent to the second access area is host vehicle 32 which is equipped with a movable boom mechanism. Most vehicle 32 is a movable mount and can be a conventional excavator. On the end of the boom a second winch 36 is attached to point of attachment for a backhoe. The winch 36 is surrounded by housing 38 that allows for free movement of cable 40 into the access area host pipe. In FIG. 1 cable 40 is shown attached to yoke 42 on cleaning bucket 26. Both cables 18 and 40 are used to engage various pieces of equipment during the rehabilitation of the host pipe.
As shown in FIG. 1 the host vehicle 32 stabilizes the boom and the winch 36 so that there is freedom of movement from the mouth of the host pipe to above ground. Boom 34 in association with winch 36 can introduce and withdraw equipment used in the rehabilitation process in and out of the second access area.
FIG. 1 is a schematic drawing showing the cleaning process. Cleaning bucket 26 is shown in more detail in FIGS. 7, 8 and 9. Referring to FIG. 7 cleaning bucket 26 is generally semi-circular with a diameter size to be received into the host pipe. The cleaning bucket 26 has a leading edge 70 with a flap door 74 hinged to the top end of one end of the bucket on a rotating hinge rod 72 that allows the flap door to swing inside the bucket from a closed to open position. A built up door stop 80 in the form of a semicircular edge extending from leading edge 70 provides a means for closing flap door 74. Any other closure means can be used. The hinge rod 72 is secured in bushings 71 and 73 that allow for swing of the hinge rod. Other retaining means that allow the hinge rod to swing are also suitable. The bucket is open at end 76 opposite to the flap door 74. Yokes 28 and 42 as shown in FIG. 1 are also shown in FIG. 7 as attachment means to engage the cables. Yoke rod 75 across the top of the bucket is provided at open end 76. FIG. 8 is an end view of the cleaning bucket 26 with the flap door 74 in the closed position. In FIG. 8 yoke pins 81 and 82 are shown which are provided on hinge 72 to hold yoke rings 84 and 86 (shown on FIG. 7) in place. Similar yoke rings and pins may be provided on yoke rode 75. Any means for holding yoke rings in place can be utilized. FIG. 9 shows the flap door 74 movement on hinge rod 72.
In FIG. 1 the cleaning bucket is being drug through the host pipe and the yokes 28 and 42 are pulled outwardly from either end of the cleaning bucket. In the cleaning process the cleaning bucket 26 is lowered into the second access area by boom 34 and winch 38. The cable 18 is attached to yoke 28 and cable 40 is attached to yoke 42. Winch 20 spools cable 18. Cleaning bucket 26 travels through the debris in host pipe 10 with the leading edge 70 being dragged first and flap door 74 pivots to the inside of the cleaning bucket. FIG. 9 shows the swing of flap door 74 that occurs during the spooling of cable 18. The drag on the cleaning bucket is reversed by spooling cable 40 on winch 36. Flap door 74 closes as it collects debris and the cleaning bucket is withdrawn to the surface. As the cleaning bucket is drawn to the surface, cable 18 is slackened to allow for withdrawal of the cleaning bucket without need to detach cable 18.
In FIG. 1 there is a schematic depiction of discharging debris the cleaning bucket into collection bin 44 at the surface near the access area. FIGS. 10a, 10b, and 10c are details of the discharge operation of the cleaning bucket. In the current embodiment fixed cable 102 is attached to the winch housing 38. Cable 102 is a fixed chain that is not attached to the winch or any other spooling mechanism. The chain is attached to yoke 28 by personnel on the site. Cable 40 is spooled to hold the cleaning bucket 26 in a relatively horizontal position so that the debris does not spill out the open end. The boom operator positions boom 34 with the winch and the cleaning bucket over collection bin 44 and spools out cable 40 allowing the bucket to tip and discharge the debris as shown in the details of FIGS. 10b and 10c. The fixed cable 102 holds the end of the cleaning bucket with the flap door in a relatively stationary position. When the leading edge 70 of the bucket is reversed for instance when the cleaning operation is in the opposite direction, the fixed chain 102 can be positioned on the other side of the winch housing.
After the discharge from the cleaning bucket it is reintroduced in the access area by boom 34 and into the mouth of the host pipe. The cable 18 is spooled up and the process is repeated until the debris is cleared from the host pipe.
FIG. 17 is a detailed perspective view of the housing 38 surrounding winch 36. The fixed cable 102 used to hold the cleaning bucket during discharge is also shown. Lines 120a and 120b supply hydraulic fluid to the winch are also shown. The winch housing surrounding the cable has an open bottom to allow for free movement of cable 40. In the preferred embodiment the winch housing is built of strong metal such as heavy steel that can bear the weight of an excavator. The bottom of the winch housing is relatively flat. The winch housing is constructed with attachment plates 121 and 123. The attachment plates are provided with attachment points which are shown as attachment pins at reference numerals 122 and 124 for plate 123 to the stick 35 of boom. The winch housing attachment pins are spaced to correspond to custom tool attachments designed for conventional excavators so that in the preferred embodiment the winch can be used on an excavator just as other custom attachments are used. FIG. 18 is a side view of winch housing 38 and the attachment to the stick portion 35 of the boom where the other custom attachments or tools are typically attached.
FIG. 21 is a detail of an embodiment with the down hole boom 14 shown attached to winch housing 21. The winch housing is constructed in the same fashion so that it attaches to end of a boom of an excavator where a bucket or other tool is generally attached. The down hole boom is configured with back to back C shaped beams spaced apart with guide rollers positioned in between the C-beams. FIG. 21 shows a down hole boom with guide roller 16 and auxiliary guide roller 13. Both guide rollers are adjustable by using pins inserted into openings along the down hole boom. In the case of guide roller 16, pin 17 is inserted through openings in C-beams and held in place by a pin retainer such as a clip, bolt and washer or other means known to those in the art. The down hole boom has numerous pins that are positioned in slots along the length of the down hole boom so that the guide rollers can be positioned as needed. As shown in FIG. 21, guide roller 16 has been positioned so that the cable is positioned to be received in the host pipe (not shown). To facilitate smooth driving of the cable additional guide rollers such as auxiliary guide roller 13 can be included along the length of the down hole boom 14. As shown in FIG. 21 the cable can be fed on either side of guide roller 16 depending on which direction cable is driven into the host pipe.
FIG. 2 is a schematic of the system figured for testing the host pipe with test mandrel 46 to determine if there is any additional debris or obstruction in the host pipe prior to lining. The same equipment is used including the down hole boom 14 with associated guide roller 16 and winch 20 which spools out and pulls cable 18. The second host vehicle 32 and associated boom 34 with winch 36 surrounded by housing 38 and cable 40 are used in the testing process. Winch 20 is shown in housing 21 and mounted to the boom of host vehicle 22. The host vehicle has travelled to the other side of the access shaft. The down hole boom 14 is shown braced against the bottom of the host pipe.
Test mandrel 46 is lowered into the access area by the boom on host vehicle 32. The test mandrel is a cylindrical member sized approximately the same diameter as the pipe liner. The test mandrel should be of sufficient length to test joint deflection in the host pipe to avoid damage to the new liner. Cables 40 and 18 are attached to the test mandrel 46 so that upon spooling the appropriate cable the mandrel may travel through the host pipe if it is clean and free of obstruction. As shown in FIG. 2, winch 20 will spool cable 18 so that the test mandrel travels to the end of the host pipe 10 at the shaft or manhole 12. Then winch 36 will spool cable 40 and pull the test mandrel back to the access area. Winch 36 is positioned so that the cable 40 can be driven into the central part of the mouth of the host pipe as shown in FIG. 2.
Detailed drawings of the test mandrel of the system are shown in FIGS. 15 and 16. Test mandrel 46 is a generally cylindrical member and has circular bevelled edges 48 and 50. FIG. 16 is a cross-section of test mandrel 46. FIG. 15 shows the internal component of the test mandrel, including ribs 52a, 52b and 52c. The ribs provide reinforcement for the test mandrel. Also, beveled edges 48 and 50 provide a final sweeping of the cleaned host pipe and assist in loosening residual deposits such as mineral deposits and other deposited debris. The ribs 52a, 52b and 52c act as weirs to collect the residual deposits inside the test mandrel in addition to providing structural support. The test mandrel of this invention also has internal yokes 54a and 54b. Yoke 54a is attached to rib 52a at slots 49 and 51. Yoke 54b is similarly situated on the other end of the test mandrel. The yokes can be made of any type of material and is shown as two cables attached to the rib with a central joinder for the cable attachment, however any other type of yoke attachment to the test mandrel could be used. The test mandrel has lifting means one of which is illustrated in FIGS. 15 and 16 as lift pin 47 which is fixed inside the test mandrel under a slot. The lift pin 47 provides an attachment means for a cable to lift the test mandrel. Other lift pins may be provided as shown in FIG. 15.
FIG. 3 illustrates the lining process using the system of the present invention. The same equipment as shown in FIGS. 1 and 2 is used to place the liner pipe in position, and in addition a pulling mandrel 56 is employed. As shown in FIG. 3, cable 18 is positioned in the central area of host pipe 10 by guide roller 16 is threaded through the host pipe to the second access area. Pipe liner sections 58, 59, 60 and 61 are shown in FIG. 3 during a lining process. The process in initiated by passing cable 18 through a first section of pipe liner (as shown in FIG. 3 pipe liner section 61) and secured to pulling mandrel 56. This process occurs in the excavated access area 30. Winch 20 pulls cable 18 approximately the length of the section of pipe liner so that the pipe liner is drawn into host pipe 10. As shown in FIG. 3 section 61 was the first section of pipe liner drawn into the host pipe. Pulling mandrel 56 is unfastened from the cable and a second section of pipe liner (pipe liner section 60 as shown in FIG. 3) is lowered into the second access area by the boom on host vehicle 32 and winch 36. The second section of pipe liner 60 is abutted to the first section of pipe liner 61 and cable 18 is pulled therethrough and secured to test mandrel 56. Winch 20 spools cable 18 pulling the first and second lengths of pipe liner so that section 60 is pulled into the host pipe and section 61 travels further into the host pipe. The process is repeated until the section of host pipe is lined.
As shown in FIG. 3 the lining process can be carried on simultaneously while another section of liner pipe 58 is positioned into the access area. Also in FIG. 3 the host vehicle 32 is shown with an operator using a remote control to manipulate the winch and boom while the lowering the pipe liner into the access area 30.
The system of this invention uses a pulling mandrel shown in more detail in FIG. 11. The pulling mandrel 56 has a circular member 62 with the flange 65 which is sized to be received in the host pipe and flange 65 contacts the circumference of the pipe liner. A plurality of spokes converge to a central hub 66. The spokes are designated with reference numerals 64a through 64h. Hub 66 has a circular opening which is sized to accompany a cable passing therethrough. The pulling mandrel allows for flow through the spokes. Also, the pulling mandrel distributes the pulling load evenly on the pipe liner. In FIG. 11 a hook 67 is shown which is used for attachment to a cable for lowering the test mandrel into the access areas when necessary. FIG. 12 shows the pulling mandrel 56 contacting a section of pipe liner 63 and illustrates the detail of the cable 61 passing through hub 66. The end of the cable 61 is secured with attachment 68 known as a teacup. Any attachment that securely fastens the cable to the hub of the pulling mandrel may be used. FIGS. 13 and 14 are exploded views showing the teacup 68, pulling mandrel 56 and section of pipe liner 63 and cable 61.
FIG. 4 is an alternative method for slip lining a host pipe that can also be performed while a sewer is in service. The alternate method can be used for remote or difficult to access areas. The alternate method uses some of the same components illustrated in the system previously described. The host pipe 200 to be cleaned is selected and access areas that will be used for the rehabilitation process are also selected. As shown in FIG. 4 two access areas at either end of the host pipe 200 are access shafts 202 and 204 which can be existing manholes. The manholes can be located in confined areas such as residential property. Down hole booms 206 and 208 are positioned vertically in the access shafts 202 and 204 respectively. Each of the down hole booms shown in FIG. 4 has at least one guide roller positioned on the end of the boom that extends above the access shaft. In the preferred embodiment, guide rollers are adjustable along the length of the down hole boom so that guide rollers can be moved on the down hole boom to position a cable in the access shaft and into the host pipe. In FIG. 4 guide rollers 210 and 212 are shown positioned on down hole booms 206 and 208 respectively.
FIG. 4 shows different types of winch placements. In access shaft 202 the winch 214 is mounted on down hole boom 206 and also mounted to a mobile vehicle 216. Cable 218 extends from winch 214 along down hole boom 206 into host pipe 200. Cable 218 passes around guide roller 210 so that it is aligned to enter the host pipe. In FIG. 4 the winch 214 is mounted on the mobile vehicle and winch 214 can serve as a positioning means to guide the cable 218 along the down hole boom 206. Another guide roller 211 which is optional is also shown on down hole boom 206.
Also shown in FIG. 4 is skid mounted winch 220. A platform or skid 222 is set up at the access shaft 204 and the winch is secured and mounted to the platform 222. When using a skid mounted winch it is preferred that the down hole boom have guide roller 224 on down hole boom 208 to guide cable 226 from winch 220 on down hole boom 208. As shown in FIG. 4, cable 226 passes around guide roller 212 to align cable 226 to enter the host pipe 200.
An excavation 228 provides an intermediate access area 228 to the host pipe 200. As shown in FIG. 4, a portion of the host pipe 200 is removed to approximately the spring line 230. Hoist 232, which may be a conventional crane, is positioned adjacent to the intermediate access area 228. The hoist has at least one cable that can be lowered into the access area. In the preferred embodiment the hoist has two cables 234 and 236 that are operated in conjunction with crane 238.
In the cleaning operation shown in FIG. 4, a cleaning bucket 240 is used essentially in the same manner as described and illustrated previously in FIGS. 1, 7, 8, 9, 10a, 10b and 10c. Cables 218 and 230 are attached to yokes 242 and 244. The cables are spooled and released by the respective winches 214 and 220 so that the bucket collects debris from both sections of the pipe extending from the intermediate access area to access shafts 202 and 204. In the alternate method, cleaning bucket 240 with trapped debris is pulled to the intermediate access area 228. Hoist cables 234 and 236 are attached to yokes 242 and 244 on the cleaning bucket. The hoist raises the cleaning bucket withdrawing it from the host pipe to the surface at the intermediate access area and further raises and tips the cleaning bucket by manipulating cables 234 and 236 to discharge the accumulated debris into collection bin 246. It is not necessary to unfasten cables 218 and 226 because the cable winches can be released out to provide enough slack. The cleaning bucket 240 is lowered into the intermediate access area 228 by hoist 232. The cleaning bucket is then drug through the debris filled host pipe in the same manner of operation as previously described to complete the cleaning of one section of the host pipe between the intermediate access area and one of the access shafts. To clean both sections of the pipe extending from the intermediate access area, it is necessary to reverse the leading edge of cleaning bucket 240 to provide for debris entrapment as previously discussed.
FIG. 5 illustrates an alterative method for testing a host pipe. The access area arrangement is similar to that in FIG. 4 which accesses host pipe 200. A skid mounted winch 250 is placed adjacent to access shaft 252 with down hole boom 254. The down hole boom skid mounted winch arrangement is previously discussed in describing FIG. 4. Access shaft 256 is serviced by winch 258 that is mounted on the bed of truck 260. Down hole boom 262 has guide rollers 264 and 266. The cable 268 from winch 258 goes around the top of guide roller 264 which is placed near the top of down hole boom 262. Guide roller 264 serves as a guide for the cable 268 to travel along down hole boom 254 into access shaft 256. Then cable 268 goes around guide roller 266 into host pipe 200. In the preferred method, guide rollers 264 and 266 are adjustably mounted along the length of the down hole boom so that they may be positioned as needed to guide the cable smoothly from the winch and into the host pipe. Similar guide rollers 270 and 272 are shown on the down hole boom associated with the skid mounted winch.
FIG. 5 shows the test mandrel 274 in host pipe 200 during the testing process. The test mandrel 274 is lowered into the intermediate access area 276 by hoist 232. The test mandrel 274 has been described in these discussions of the invention. Cable 278 from the skid mounted winch is attached to test mandrel 274 at the point of attachment on one end of the test mandrel while the test mandrel 274 is in the intermediate access area. Cable 278 is attached to the opposite end of test mandrel 274 while the test mandrel is in the intermediate access area. The test mandrel 274 is sized to fit inside the host pipe and pulled through the host pipe to be tested for obstructions. In addition, the test mandrel used can be described previously in FIGS. 15 and 16 also provides an additional final sweep to collect mineralized deposits or residual debris. The test mandrel 74 is pulled through the test pipe by alternatively spooling the skid mounted winch 250 and the truck mounted winch 258 through the host pipe 200. The test procedure is completed. The test mandrel is removed from host pipe 200 using hoist 232.
FIG. 6 illustrates the slip lining process of the alternative method. In FIG. 6 the host pipe 200 is accessed at intermediate access area 276. The skid mounted winch 250 is placed in the same position as shown in FIG. 5. Down hole boom 254 is placed in access area 252. Skid mounted winch 255 drives cable 278 into the host pipe using down hole boom 254 and guide rollers 270 and 272 assisting in positioning cable 278. In access area 256 the winch mounted on the truck bed has been replaced by a winch 280 mounted to a down hole boom 282 and also mounted to the stick of boom 284 of excavator 286.
As can be seen from FIGS. 4, 5 and 6, the down hole boom mounts into the access shafts can utilize any type of mounting vehicle or skid placement which will secure a down hole boom vertically in an access shaft. Winch 280 serves as a guide for cable 288 along the down hole boom. Although guide roller 290 is shown, it is optional as previously described. Guide roller 292 at the bottom of down hole boom 282 aligns the cable into host pipe 200. As previously discussed, the guide rollers are adjustable to provide proper alignment of the cable down the access shaft and into the host pipe.
FIGS. 19 and 20 are details of the down hole booms used with alternate method and system shown in FIG. 4, 5 and 6. In FIG. 19 down hole boom 350 is shown with hook 352 fixed to top plate 364 with attachment pins 386a, 386b, 386c and 386d. The top plate 364 is attached to corner pieces 383 and 384 through which pins 386a, 386b, 386c and 386d extend to C-beams 388 and 390. The C-beams are positioned facing each other with spacing to accommodate guide rollers in between, as shown in FIG. 19 which is provided for ease in transport and set up. Adjustable guide roller 354 is disposed in between C-beams 388 and 390. At the end of the C-beams is bottom plate as shown on C-beam 388 extending from the corners of the C-beam. Joinder pins 396 and 398 extend through openings in the bottom plate 388 through top plate 390 of C-beam 400 which abuts C-beam 366. C-beam 402 faces C-beam 400. Adjustable guide roller 356 is disposed between C-beams 400 and 402. C-beam 400 has end plate 394 provided for joinder to additional C-beams. C-beam 402 has top plate 392 and a bottom plate (not shown) for joinder to adjacent C-beams as described above. A series of straps 370, 372, 374, 376, 378 and 380 are welded to the outside corners of the C-beams and provide spacing for the C-beams of the guide rollers. The guide rollers are adjustable as previously discussed to align the cable 358 from a mounted winch such as a skid or truck mounted winch the down hole boom into the host pipe (not shown). The guide rollers are adjustable by removing pins 360 and 362 and repositioning the guide rollers with other pins of the down hole boom as discussed above for FIG. 21.
FIG. 20 is the same embodiment as FIG. 19 except cable 358 is placed on guide rollers 354 and 356 to illustrate how the guide rollers can be used to re-orient the direction of the cable if necessary. The cable 358 can be fed to the same or opposite direction from the winch feed depending on the side of guide roller 356 the cable is wrapped.
Hoist 232 is positioned at intermediate access area 276. During the lining process hoist 232 lowers sections of pipe liner into the intermediate access area. Cables 278 and 288 pass through the host pipe to the intermediate access area. The cable is then passed through a section of pipe liner that has been lowered into the intermediate access area and the cable is further threaded through a pulling mandrel and secured. This general process has been described previously for the system of this invention.
FIG. 6 illustrates the simultaneous lining process for the sections of host pipe extending from the intermediate access area 276. If desired the lining operation could be performed on one section of the host extending from the intermediate area to an access shaft and then the other section. In FIG. 6 pipe liner sections 294, 296,297 and 298 have been inserted into the host pipe 200.
For example, pipe liner 296 was lowered into the access area 276 and placed adjacent to section 294 which had been inserted into host pipe 200. The cable 288 was passed through both pipe liner sections 294 and 296 and secured to pulling mandrel 302. Winch 280 was spooled to pull pipe liners 294 and 296 into host pipe 200. The same operation was performed with pulling mandrel 302 and pipe liner 294.
When each section of pipe liner has been pulled into the host pipe approximately the length of the liner section another section of pipe liner is introduced into access area 272. The pulling mandrel is removed from the cable and the new section of liner pipe is placed into the mouth of the host pipe, the cable is drawn through the additional section of liner pipe and secured to the test mandrel. In the direction of access shaft 252 pulling mandrel 304 secured to cable 278 pulls pipe liner section 298 and 297 into host pipe 200. The operation of the pulling mandrel has been previously discussed and the pulling mandrel is shown in FIGS. 11, 12, 13 and
The description provided herein is not intended to cover all the embodiments and methods of the claimed invention. Other variations will be understandable to those skilled in the art. | A rehabilitation system has been developed for cleaning, testing and slip lining pipe particularly sewer lines while in service. The system includes the use of equipment adapted for use on mobile vehicles to increase efficiency and mobility of the system. The cleaning system utilizes a specialized cleaning bucket that can be pulled from excavations and existing manholes. The testing and lining systems also utilize specialized test mandrels and pulling mandrels for the pipe liner that can be used with equipment operating, in part, from existing manholes. | 4 |
CROSS-REFERENCE
This application is a divisional of U.S. application Ser. No. 11/836,903 filed Aug. 10, 2007 which is a continuation-in-part of U.S. application Ser. No. 10/804,841 filed Mar. 19, 2004.
GOVERNMENT RIGHTS
This application was developed under National Science Foundation Small Business Innovative Research Grant No. IIP-0944707.
FIELD OF THE INVENTION
The present invention relates to a method and apparatus for controlling the hydrodynamics in a plating cell to facilitate more uniform deposition across a workpiece such as a printed circuit board.
BACKGROUND OF THE INVENTION
The continuing miniaturization of electronic devices is driving the design of interconnects in the direction of finer pitch surface tracks, smaller diameter through holes and vias, and thicker workpieces to provide increased circuit densities (Paunovic, M. and M. Schlesinger, 2000) 1 . This trend has significant implications for the electronics industry which must ensure that the metal electrodeposition process meets the functionality and quality requirements of these advanced workpiece device designs. These workpieces include printed circuit boards, chip scale packages, wafer level packages, printed wiring boards, high density interconnect printed wiring boards, high density interconnect printed circuit boards and the like and these workpieces often have at least one through hole extending from a first surface of the workpiece to a second surface of the workpiece.
For economies of production, the range of approximate dimensions of workpieces is typically 6 inch by 6 inch, 10 inch by 18 inch, 18 inch by 24 inch, 2 meters by 2 meters, 5 meters by 5 meters, and 200 millimeters and 300 millimeters in diameter. However, these range of dimensions are not unique and are not limiting to the need for controlling the hydrodynamics in a plating cell to facilitate uniform deposition across a workpiece.
As the hole and via diameter decrease, the workpiece thickness increases, and the workpiece dimension increases, the most notable challenge for the quality of metal electrodeposits is the avoidance of non-uniform copper thickness distribution over board surfaces and within through holes, i.e. the challenge of leveling or throwing power, which can adversely affect the performance of the finished printed wiring board interconnect (Paunovic, M. and M. Schlesinger, 1998) 2 , (Ward, M., D. R. Gabe and J. N. Crosby, 1999a) 3 .
A number of operating parameters and plating cell attributes influence the uniformity of copper deposition onto a workpiece. This invention concentrates on the influence of electrochemical cell configuration on the uniformity of copper deposition on the board surface, in particular, the influence of cell configuration on solution hydrodynamics, and the ability to generate uniform flow of electrolyte across the surface of the board during the plating operation. FIG. 1 shows a plating cell ( 100 ) which contains a workpiece ( 102 ). Although only one workpiece is shown in this and subsequent drawings, one skilled in the art understands that in actual practice a plurality of workpieces may be contained in the plating cell. For ease of description, the term workpiece is understood to encompass one or more workpieces. The workpiece ( 102 ) in prior art FIGS. 2-3 , 5 , and 7 - 9 is presented as a generally flat panel having at least one generally flat surface for electroplating. Arrows ( 104 ) indicate the desired uniform flow of electrolyte across the entire surface of the workpiece ( 102 ).
FIG. 2 shows a conventional workpiece ( 102 —shown in a side-view relative to its appearance in FIG. 1 ) plating operation, in which flow of electrolyte is achieved by air sparging. Air bubbles ( 106 ) are created in the electrolyte by blowing air through pipes ( 108 ) which have holes in them. These pipes are positioned on the bottom of the plating cell ( 100 ) beneath the workpiece ( 102 ). The number of pipes ( 108 ) is not limited. The movement of air bubbles ( 106 ) from the bottom to the top of the plating cell ( 100 ) creates solution movement, as indicated by the arrows ( 104 ). However, air sparging can create problems in the plating operation:
the oxygen can oxidize components of the electrolyte, the oxygen can oxidize features and circuit patterns on the workpiece, air bubbles ( 106 ) may become trapped in features in the workpiece ( 102 ), creating areas where copper cannot be deposited, this method can generate low solution movement rates, which can result in burning of the workpiece ( 102 ) at high current densities, and as the air bubbles progress towards the top of the cell they grow in size and can create a non-uniform solution environment from the bottom of the workpiece to the top.
To avoid the problems associated with air sparging, eductors are being tested for use in plating cells designed for workpieces. Eductors are nozzles which utilize venturi effects to provide up to five times the solution flow velocity output of the pump which feeds the eductors. Eductors may be obtained commercially from a number of sources; one such eductor is marketed under the name Serductor™ (Serductor™ is a trademark of Serfilco, Northbrook, Ill.) 4 .
One configuration of a prior art plating cell is shown in FIG. 3 . The plating cell ( 100 ) contains a workpiece ( 102 ) which hangs on a rack ( 110 ). Anodes ( 112 ) are positioned on either side of the workpiece ( 102 ) and hang from rails ( 114 ). The workpiece ( 102 ) serves as the cathode. Eductors ( 116 ) are positioned behind the anodes ( 112 ) horizontally opposite (perpendicular to) the surface of the workpiece ( 102 ) (Weber, A., 2003) 5 . Fluid flow is directed (shown by the arrows ( 104 )) from the eductors ( 116 ) between the anodes ( 112 ) to the surface of the workpiece ( 102 ). This type of eductor arrangement leads to impinging fluid flow whereby the solution flow velocity is directed toward the workpiece. Solution flow velocity is accomplished through the anodes by openings or spaces in the anodes.
However, as shown in FIG. 4 , the use of eductors ( 116 ) can lead to a variation in solution flow velocity across the workpiece ( 102 ) (Chin, D-T. and C-H. Tsang, 1978) 6 , (Hsuch, K-L. and D-T. Chin, 1986a) 7 , (Hsuch, K-L. and D-T. Chin, 1986b) 8 . Fluid flows from the eductor ( 116 ) to the impingement point ( 118 ) on the surface of the workpiece ( 102 ). The fluid flow profile ( 120 ) and jet centerline ( 122 ) are shown. The flow from the eductor ( 116 ) is directly perpendicular to the surface of the workpiece ( 102 ). In region I, referred to as the potential core region, the flow from the eductor ( 116 ) mixes with the surrounding electrolyte. In region II, referred to as the established flow region, the velocity profile ( 124 ) is well established, and the solution flow velocity decreases as a function of distance from the eductor ( 116 ). In region III, referred to as the stagnation region, the velocity decreases to almost zero, and the boundary layer thickness is relatively independent of the radial position near the impingement point ( 118 ) and centerline ( 122 ). In region IV, referred to as the wall jet region, the radial velocity decreases and the boundary layer thickness increases, as a function of distance radially outward from the impingement point ( 118 ). These variations in solution flow velocity, termed the glancing effect, within regions III and IV contribute to variations in the thickness of copper deposited on the surface of the workpiece ( 102 ).
Efforts to improve the uniformity of flow under the impinging eductor flow configuration have included movement of the workpiece ( 102 ) while maintaining the same distance between the workpiece and the eductor ( 116 ). While the workpiece movement has generally been reported as left and right, the workpiece movement could conceivably be up and down or even at an angle while maintaining the same distance relative to the eductor. The goal of such movement is to produce a time-averaged uniform boundary layer across the workpiece ( 102 ). Such movement, particularly left and right movement is termed knife edge agitation by those skilled in the art. However, knife edge agitation still can result in non-uniformity of the deposited copper and adds complexity to plating cell design. Furthermore, incorporation of knife edge movement in existing workpiece plating lines is difficult and costly.
An alternative prior art configuration shown in FIG. 5 positions the eductors ( 116 ) below and off to either side of the workpiece, pointing obliquely at the workpiece surface ( 102 ) (Ward, M., D. R. Gabe, and J. N. Crosby, 1998) 9 , (Ward, M., D. R. Gabe, and J. N. Crosby, 1999b) 10 .
However, as shown in FIG. 6 , the use of angled eductors ( 116 ) can lead to a variation in solution flow velocity across the workpiece ( 102 ) (Chin, D-T., and M. Agarwal, 1991) 11 . Fluid flows from the eductor ( 116 ) to the impingement point ( 118 ) on the surface of the workpiece ( 102 ). The fluid flow profile ( 120 ) and jet centerline ( 122 ) are shown. The flow from the eductor ( 116 ) is at an oblique angle to the surface of the workpiece ( 102 ). In region I, the potential core region, the flow from the eductor ( 116 ) mixes with the surrounding electrolyte. In region II, the established flow region, the velocity profile ( 124 ) is well established, and the solution flow velocity decreases as a function of distance from the eductor ( 116 ). In region III, the stagnation region, the velocity decreases to almost zero, and the boundary layer thickness is relatively independent of the radial position near the impingement point ( 118 ) and centerline ( 122 ). In this case, the stagnation point is shifted from the jet centerline. In regions IV and V, the wall jet regions, the velocity decreases and the boundary layer thickness increases, as a function of distance radially outward from the impingement point ( 118 ). Furthermore, the solution velocity and boundary layer thickness in region IV is different from that in region V. The glancing effect produces variations in solution flow velocity within regions III, IV, and V, and contributes to variations in the thickness of copper deposited on the surface of the workpiece ( 102 ).
An alternative configuration shown in FIG. 7 positions the eductors ( 116 ) below and off to either side of the workpiece, pointing obliquely across the workpiece ( 102 ) (Weber, A., 2003) 5 . The eductors ( 116 ) on one side of the workpiece ( 102 ) are pointed in one direction, and in the opposite direction on the other side (not shown in FIG. 7 ) of the workpiece ( 102 ). This is intended to create a swirling solution movement around the workpiece ( 102 ). However, the glancing effect described above applies in this case, leading to non-uniform flow of solution across the workpiece ( 102 ).
An alternative configuration shown in FIG. 8 positions the eductors ( 116 ) directly below the workpiece ( 102 ), pointing directly up so that solution moves past the surface of the workpiece ( 102 ) (Weber, A., 2003) 5 (Carano, M., 2003) 12 . Again, the glancing effect described above applies in this case, due to mixing of the flow profiles from the multiple eductors ( 116 ) positioned below the workpiece ( 102 ). This contributes to non-uniform flow of solution across the workpiece ( 102 ).
An alternative configuration shown in FIG. 9 positions the eductors ( 116 ) directly below and off to either side of the workpiece ( 102 ), pointing directly up so that solution moves past the surface of the workpiece ( 102 ) (Carano, M., 2003) 12 . The glancing effect described above applies in this case, contributing to non-uniform flow of solution across the workpiece ( 102 ).
Accordingly, a need exists for a method and apparatus which controls the hydrodynamics within a plating cell ( 100 ), to facilitate uniform distribution of metal onto a workpiece ( 102 ). This invention concentrates on the influence of cell configuration on the uniformity of deposition across the surface of the workpiece ( 102 ) as reflected in a low coefficient of variability.
SUMMARY OF THE INVENTION
The present invention relates to a method and apparatus for controlling the hydrodynamics in an electroplating cell (hereinafter called a plating cell), to facilitate a more uniform metal deposit distribution across the workpiece using an electrochemical plating process, wherein the metal deposit may be any metal of interest including but not limited to copper, gold, nickel, tin, lead-tin solder. More uniform deposition is a product of more uniform current distribution which is achieved at least in part from more uniform solution flow velocity across the workpiece. Uniform deposition is observed in a coefficient of variability (CoV) that is low by industry standards. In accordance with certain embodiments of the invention CoV less than about 10% and in many cases less than about 7% and in many cases on the order of about 5% or less is achieved.
One embodiment of the present invention more particularly relates to controlling the hydrodynamics in a plating cell, to facilitate uniform metal deposit distribution across a chip scale package using an electrochemical plating process.
Another embodiment of the present invention relates to controlling the hydrodynamics in a plating cell, to facilitate uniform metal deposit distribution across a wafer level package using an electrochemical plating process.
Still another embodiment of the present invention relates to controlling the hydrodynamics in a plating cell, to facilitate uniform metal deposit distribution across a printed wiring board using an electrochemical plating process.
Another embodiment of the present invention particularly relates to controlling the hydrodynamics in a plating cell, to facilitate uniform metal deposit distribution across a high density interconnect printed wiring board using an electrochemical plating process.
Still another embodiment of the present invention particularly relates to controlling the hydrodynamics in a plating cell, to facilitate uniform metal deposit distribution across a high density interconnect printed circuit board using an electrochemical plating process.
Still another embodiment relates to controlling the hydrodynamics in a plating cell to facilitate metal deposition on the walls of a through hole.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic illustration of the cross-section of a plating cell containing a workpiece, with arrows showing the desired uniform solution flow velocity across the surface of the workpiece.
FIG. 2 is a schematic illustration of a prior art cell depicting the cross-section of a plating cell containing a workpiece and two anodes, with air sparging.
FIG. 3 is a schematic illustration of prior art depicting the cross-section of a plating cell containing a workpiece and two anodes, with horizontal eductors.
FIG. 4 is a schematic illustration of the velocity profile of the flow from an eductor directed onto the surface of a workpiece when the eductor is perpendicular to the workpiece in a prior art cell.
FIG. 5 is a schematic illustration of prior art depicting the cross-section of a plating cell containing a workpiece and two anodes with angled eductors.
FIG. 6 is a schematic illustration of the velocity profile of the flow from an eductor directed onto the surface of a workpiece, when the eductor flow is at an angle which is not 90° with respect to the workpiece in a prior art cell.
FIG. 7 is a schematic illustration of prior art depicting the cross-section of a plating cell containing a workpiece and two anodes, with angled eductors.
FIG. 8 is a schematic illustration of prior art depicting the cross-section of a plating cell containing a workpiece and two anodes, with vertical eductors directly below the workpiece.
FIG. 9 is a schematic illustration of prior art depicting the cross-section of a plating cell containing a workpiece and two anodes, with vertical eductors below and to either side of the workpiece.
FIG. 10 is a schematic illustration of the cross-section of a plating cell in accordance with one embodiment of the present invention, viewed from the top, for controlling hydrodynamic flow within the plating cell, to enhance uniformity of electrochemical deposition of copper onto a workpiece. This figure shows the flow of electrolyte from the eductors to the workpiece, and out through a hole in a baffle in the plating cell, to a side chamber, the anodes and anode chambers, the porous fiber cloth on the anode chambers, and the workpiece. The non-conducting shielding on the anode chamber is not shown in FIG. 2 so that the porous fiber cloth can be seen in the figure.
FIG. 11 provides another schematic illustration of the plating cell shown in FIG. 10 , viewed from a side along the direction 11 - 11 of FIG. 10 . Attributes of the plating cell shown in this figure include eductors, vertical vibration, oscillation perpendicular to the face of the panel workpiece, anode to workpiece distance, use of an anode chamber, use of a porous fiber cloth across the front of the anode chamber, anode non-conducting shielding and use of a baffle.
FIG. 12 provides another schematic illustration of the plating cell shown in FIGS. 10 and 11 viewed from a side along the direction 12 - 12 of FIG. 10 . This figure shows the flow of electrolyte through the eductors, vertically up past the workpiece, and into a side chamber, from where it is pumped back to the eductors. The anodes and anode chambers are not shown in this view.
FIG. 13 is a schematic illustration of the thirty-six thickness measurement points on the copper foil, pulled off the stainless steel panel used in the plating experiments described in Examples 2 and 3.
FIG. 14 is a set of graphs showing the effects of changing the attributes in the plating cell on the uniformity of metal deposition on a flat stainless steel panel. The smaller the coefficient of variance (CoV), the more uniform the metal deposition
FIG. 15 is a schematic illustration of a plating cell depicting uniform electrolyte flow across both surfaces of the workpiece.
FIG. 16A is a schematic illustration depicting a plating cell in which the electrolyte flows across the first surface of the workpiece at a flow velocity greater than the flow velocity of the electrolyte flowing across the second surface of the workpiece.
FIG. 16B is a schematic illustration depicting a plating cell in which the electrolyte flows across the first surface of the workpiece at a flow velocity less than the flow velocity of the electrolyte flowing across the second surface of the workpiece.
FIG. 17A is a schematic illustration depicting a plating cell in which the electrolyte is injected across the first surface of a workpiece having at least one through hole at a flow velocity greater than the flow velocity of the electrolyte injected across the second surface of the workpiece. The illustration depicts a workpiece with one through hole, but there could be a plurality of through holes in the workpiece. Additionally, it is shown that the electrolyte is drawn through the through hole from the second surface of the workpiece to the first surface by the flow velocity difference.
FIG. 17B is a schematic illustration depicting a plating cell in which the electrolyte is injected across the first surface of the workpiece at a flow velocity less than the flow velocity of the electrolyte injected across the second surface of the workpiece. Additionally, it is shown that the electrolyte is drawn through the through hole from the second surface of the workpiece to the first surface by the flow velocity difference.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
In the following detailed description, reference is made to the accompanying drawing. which form a part hereof, and in which are illustrated specific embodiments in which the invention may be practiced.
Those skilled in the art will recognize that the invention is not limited to the specific embodiments illustrated in these drawings. In the drawings, the following parts have been identified by the following numbers.
100.
Plating cell
101.
First surface of workpiece
102.
Workpiece
103.
Second surface of workpiece
104.
Arrow indicating electrolyte flow
104(a).
Arrow indicating high-velocity electrolyte flow
104(b).
Arrow indicating low-velocity electrolyte flow
105.
Arrow indicating direction of
electrolyte flow within a through hole
106.
Air bubbles
107.
Through hole
108.
Pipe
110.
Rack
112.
Anode
114.
Rail
116.
Eductor
118.
Impingement point
120.
Fluid flow profile
122.
Jet centerline
124.
Velocity profile
126.
Anode chamber
128.
Porous fiber cloth
130.
Non-conducting shielding
132.
Pump
134.
Manifold
136.
Guide
138.
Baffle
140.
Arrow indicating electrolyte flow
142.
Arrow indicating electrolyte flow
144.
Hole
146.
Baffle
148.
Side chamber
150.
Outlet hole
152.
Arrow indicating vertical vibration
154.
Arrow indicating oscillation
156.
Copper foil
158.
Measuring point
FIGS. 10 to 12 show one embodiment of the present invention in a series of cross-sectional views. The following detailed description of the preferred embodiments refers to these figures. The plating cell ( 100 ) was designed with a range of attributes for enhancing the uniformity of deposition over the workpiece ( 102 ). The attributes are variable high velocity eductor-induced agitation, lateral oscillation of the workpiece perpendicular its face, use of an anode chamber, variable anode to workpiece distance, variable frequency vertical vibration of the workpiece, and non-conducting shielding of the anodes within the anode chamber. In the plating cell ( 100 ), the workpiece ( 102 ) serves as the cathode for metal deposition.
The plating cell ( 100 ), which, in one embodiment, holds 1700 liters of bath electrolyte is capable of accommodating one rack or workpiece holder ( 110 ) which holds one workpiece ( 102 ). In this embodiment, the workpiece is 18 inches by 24 inches high. The size of the plating cell ( 100 ), the number of workpieces ( 102 ), dimensions of the workpiece ( 102 ) and other specific details given here relate to a particular embodiment that was evaluated experimentally and are not limiting.
Sets of anodes ( 112 ) are hung on rails ( 114 , FIGS. 10 and 11 ) on each side of the rack ( 110 ) and facing the workpiece ( 102 ), and may be encased in an anode chamber 126 ( FIGS. 10 and 11 ). These anodes may be plates or, more typically, they are a panel of metallic balls. The anode chamber ( 126 ) may have a porous fiber cloth ( 128 ) between the anodes ( 112 ) and workpiece ( 102 ). The cloth may be formed from a polymeric material. This cloth ( 128 ) spreads the current distribution between the anodes ( 112 ) and the workpiece ( 102 ) such that the anode chamber ( 126 ) acts as a virtual anode. One cloth was obtained from CROSIBLE FILTRATION, located in Moravia, N.Y. 13118. It was specifically a 100% polypropylene filter material. The reported porosity was 2-4 cubic feet per minute. Other filter cloth available has a porosity of 20-30 cubic feet per minute. A wide variety of filter cloths would be acceptable provided they have pores small enough that for the given distance between the cloth and the workpiece the cloth serves as a virtual anode.
Non-conducting shielding ( 130 ) at the top of the anode chamber ( 126 ) prevents edge effects from affecting the uniformity of copper deposition on the workpiece ( 102 ). The distance from the anode chamber ( 126 ) to the workpiece ( 102 ) is adjustable, with a range varying from about 165 to 300 mm, and preferably from about 210 mm to 250 mm, and more preferably from about 210 to 220 mm.
In one embodiment two 300 L/min pumps ( 132 ) are used to circulate electrolyte through manifolds ( 134 ) on either side of the plating cell ( 100 ) and through eductors such as ½ in eductors ( 116 ) located horizontally under the anode chambers ( 126 ). In FIGS. 10-12 , three eductors ( 116 ) are shown on each side of the plating cell ( 100 ). In one embodiment, the eductors are spaced on 6 inch centers, but the number of eductors ( 116 ) and the spacing may change from those cited and is not limiting. The number and placement of eductors ( 116 ) should be chosen so as to facilitate uniform flow of electrolyte across the entire surface of the workpiece ( 102 ) as described herein.
Electrolyte flowing out of the eductors ( 116 ) is directed vertically past the workpiece ( 102 ) by a solution flow velocity dampening member ( 136 ), whereby the variations in electrolyte solution are suppressed. In one embodiment of the invention, the solution flow velocity dampener is a series of shaped guides ( 136 ) located below the workpiece ( 102 ). The use of the shaped guides ( 136 ) directs the solution flow parallel the surface of the workpiece thereby dampening the variations in solution flow velocity described above in the prior art, reducing the glancing effect, and resulting in more uniform flow across the surface of the workpiece ( 102 ). The solution flow velocity dampening members that are useful herein may have a variety of shapes. For example, curved panel sections with various radii of curvature relative to the surface of the workpiece and flat ramps with various incline angles relative to the surface of the workpiece. As taught herein, the optimum configuration for the shaped dampening member is easily determined without undue experimentation by those of ordinary skill in the art. The radius of curvature utilized for one embodiment was 8.25 inches. A useful range may be about 6 to 12 inches for a plating cell in which the distance between the bottom of the shaped guide and the workpiece is approximately 10.5 inches.
Baffles ( 138 , FIG. 11 ) below each anode chamber ( 126 ) prevent solution from flowing back to the other side of the anode chamber ( 126 ). The velocity of the electrolyte flowing past the workpiece ( 102 ) can be changed by 1) changing the pump ( 132 ) settings and 2) moving the anode chambers ( 126 ) closer to the workpiece ( 102 ). The electrolyte flows vertically up (indicated by arrows 104 ) past the workpiece ( 102 ) and then across (indicated by arrows 140 ) the top of the plating cell ( 100 ) and out (indicated by arrow 142 ) through a hole ( 144 ) in a baffle ( 146 ) in the plating cell ( 100 ) to a side chamber ( 148 ). Solution is suctioned through outlet holes ( 150 ) from the side chamber ( 148 ) through the pump(s) ( 132 ) and back through the manifolds ( 134 ) and out through the eductors ( 116 ). The side chamber ( 148 ) with its enclosed electrolyte and in conjunction with pump(s) ( 132 ) and manifold ( 134 ) serves as an electrolyte supply system. In one embodiment, as electrolyte is pumped through the eductors ( 116 ), electrolyte in the plating cell ( 100 ) is pulled into the eductors ( 116 ) in about a 4:1 ratio (4 parts electrolyte pulled into the eductors ( 116 ) from the plating cell ( 100 ) to 1 part electrolyte pumped through the eductors ( 116 )) to increase the flow of electrolyte past the workpiece ( 102 ). A filter (not shown) in the side chamber ( 148 ) can be used to maintain cleanliness of the electrolyte.
In some cases, uniformity of metal distribution over the workpiece ( 102 ) can be improved by vibration of the workpiece ( 102 ). Vibration is in the vertical direction as shown by the double-ended arrow ( 152 ) adjacent to the rack ( 110 ) in FIG. 11 . Vibration may be particularly important for workpieces with interconnect features such as fine pitch surface tracks, through holes, vias and the like. Vibration of the workpiece ( 102 ) is accomplished by two horizontally mounted rotary eccentrically weighted devices powered by variable speed motors (not shown) and mounted to each end of the load bar (not shown) to which the rack ( 110 ) is attached. Those skilled in the art understand that other means for accomplishing vibration include, but are not limited to; pneumatic rotary ball device, pneumatic rotary turbine device, electromagnetic linear motion device, pneumatic sliding piston device, and ultrasonic electromagnetic device. The frequency of vibration available using this configuration typically ranges from about 0 to 3570 cycles per minute.
Oscillation of the workpiece ( 102 ) perpendicular to the anodes ( 112 ), as shown by the double-ended arrow ( 154 ) above the rack ( 110 ) in FIG. 11 , or oscillation of the anodes ( 112 ) perpendicular to the workpiece ( 102 ) or oscillation of both anodes ( 112 ) and workpiece ( 102 ) with respect to each other results in the flow of electrolyte through the holes in the workpiece ( 102 ), improving the current distribution and therefore plated metal distribution on the workpiece ( 102 ). Oscillation may be particularly important for workpieces with interconnect features such as fine pitch surface tracks, through holes, vias and the like. In one embodiment, oscillation of the workpiece ( 102 ) is produced by a positive drive from a variable speed motor-reducer with crank arm and linkage (not shown). Those skilled in the art understand that other means for accomplishing oscillation include, but are not limited to reversing rack and pinion device, off axis side crank device, grooved cam traverse mechanism device, yoke strap eccentric circular cam mechanism device, reversible worm screw jack device, electromechanical linear drive device, and reversible pneumatic or hydraulic cylinder device. The frequency of oscillation can shift from about 6 to 63 cycles per minute with a stroke of about 25 mm, although this range is not limited. This is the method of oscillation employed in this plating cell ( 100 ), although the invention is not limited to this method. Thus in one embodiment, the workpiece ( 102 ) is moved parallel to and/or perpendicular to the anodes ( 112 ).
In accordance with certain embodiments of the invention, uniformity of metal distribution over the workpiece ( 102 ) can be improved by changing the distance between the anodes ( 112 ) and the workpiece ( 102 ). The distance from the anode chamber ( 126 ) to the workpiece 102 may vary from about 165 to 300 mm, preferably from about 210 mm to 250 mm, and more preferably from about 210 to 220 mm.
Uniformity of metal distribution over the workpiece ( 102 ) can also be improved by placing non-conducting shielding ( 130 ) at the top of the anode chamber ( 126 ) to reduce edge effects.
Uniformity of metal distribution over the workpiece ( 102 ) can be further improved by placing a baffle ( 138 ) at the bottom of the anode chamber ( 126 ).
The invention is particularly useful in plating circuit boards having features such as through holes and vias. Because more uniform deposition is available in accordance with the invention, good plating of the features can be achieved independently of the location of the feature on the workpiece. Thus workpiece having more demanding features to plate can be successfully processed substantially independently of the location of the feature on the workpiece. Problems associated with uneven deposition due to uneven boundary layer due to uneven plating solution flow are minimized and a robust plating technique is provided.
In electroplating methods in which the electrolyte solution is injected parallel to the surfaces of a workpiece, a equal flow velocity ( 104 ) may be applied across both the first surface ( 101 ) and the second surface ( 103 ) of the workpiece ( 102 ) as shown in FIG. 15 . Another embodiment of the invention enables plating within through holes is illustrated in FIGS. 16A-B and FIGS. 17A-B . The through hole ( 107 ) is representative of one or more through holes. It is understood in the art that the workpiece can have a plurality of through holes. In FIG. 16A , the flow velocity of the electrolyte is adjusted in such a manner that a greater flow velocity ( 104 a ) is applied across the first surface ( 101 ) of the workpiece than the flow velocity ( 104 b ) applied across the second surface ( 103 ). FIG. 16B shows that, alternately, the high-velocity electrolyte flow ( 104 A) can be applied across the second surface ( 103 ) and the low-velocity electrolyte flow ( 104 b ) can be applied to the first surface ( 101 ).
Although not bound by theory, different flow velocities across the first and second surfaces will generate flow through the through hole as described below. This flow velocity differential will create a high fluid pressure on the surface of the workpiece with the lower flow velocity ( 104 b ) and will create a low fluid pressure on the first surface ( 101 ) having the higher flow velocity ( 104 a ). This pressure differential will induce flow ( 105 ) within the through holes ( 107 ), openings that extend throughout the width of the workpiece ( FIGS. 17A-B ). This will cause the plating bath solution from the high-pressure side to flow through the hole and towards the low-pressure side of the workpiece. This method enables metal deposition within the through holes by providing fresh plating bath and by sweeping away any accumulated by-products.
A further embodiment of the invention is the use of two or more pumps to modulate the flow velocity of the electrolyte bath solution. The first pump can be used to inject electrolyte bath solution into eductors setup to direct the flow via the shaped guides across the first surface of the workpiece. The second pump can be used to inject bath solution into eductors set up to direct the flow via the shaped guides across the second surface of the workpiece. The first and second pumps can either have controls to regulate their speed (RPM) or have fixed speed capability. Whether variable or fixed, the pumps should be operated such that when utilized in unison they set up a flow velocity differential across either side of the workpiece. In addition, a fixed and a variable pumping devices can be used together, once again, provided that their operation generates the desired flow velocity differential.
Another embodiment of the invention is the use of valves as a means of modulating flow velocity. In this embodiment valves can be inserted in between the pump and the eductors. The degree of closure of the valves affects the flow velocity of the electrolyte solution prior to entering the eductors. Either a single or multiple pumps may be used in conjunction with the valves. Using a single pump, the conduit from the pump can be bifurcated into two separate conduits: a first conduit for injecting electrolyte bath solution through eductors that direct the solution via the shaped guides across the first surface of a workpiece and a second conduit for directing the bath solution via the shaped guides across the second surface. Valves can be placed in either one or both of the conduits. The valves can be adjusted such that the requisite flow differential is established. Multiple pumps can be utilized in the same way as described in the previously stated embodiment with the addition of valves to provide a further means for regulating the flow velocity.
An even further embodiment of the invention is the use of one or more flange connections in the conduits. Just as the valves in the above embodiment, the flange connections are placed in between the pump and the eductors. In between the connections a disc with an orifice can be inserted that restricts the diameter of the conduit. Orifice size also contributes to the flow velocity across the workpiece. Therefore the flange connectors can be utilized with one or more pumps to regulate the flow velocity across the workpiece. As in the case of the valve when using a single pump, the flange connectors can be placed in either the first conduit or second conduit or in both. While the valves may be adjustable and therefore their affect on flow velocity adjustable, the flange connections' affect on fluid velocity is limited by the size of the orifice selected. Even so, the flange connections can serve as either the sole means of regulating flow velocity or as an additional means in conjunction with pumps and valves.
The invention will be illustrated by the following examples, which are intended to be illustrative and not limiting.
Example 1 (Comparison)
This example illustrates the use of the plating cell ( 100 ) with air sparging to deposit copper onto a workpiece ( 102 ), to demonstrate the prior art.
The experiments were conducted in the plating cell ( 100 ) shown in FIG. 2 . An acid copper sulfate electrolyte containing ˜97 g/L CuSO 4 , 210-215 g/L of concentrated H 2 SO 4 , ˜63 ppm CF, and 350 ppm polyethylene glycol (PEG) was used as the copper electroplating bath. As known by those skilled in the art, the chloride/PEG acts as a suppressor and is not difficult to control. The plating bath does not contain difficult-to-monitor/control additives such as brighteners and/or levelers and hence the bath is considered “additive-free.” The plating bath temperature was maintained in the range of 22 to 25° C.
The initial experiments for plating cell ( 100 ) characterization were conducted on a stainless steel panel (450 mm×600 mm), as a workpiece ( 102 ). The copper plating process was controlled by DC current at 25 A/ft 2 (provided by a PE86 dual output rectifier) to obtain a copper film with a thickness of about 25 micrometers on both surfaces of the stainless steel panel
After each test, copper foils ( 156 ) that plated on both sides of the stainless steel panel workpiece ( 102 ) were peeled off to analyze the copper thickness distribution. FIG. 13 illustrates the position of each measuring point ( 158 ) on the copper foil ( 156 ). There were thirty-six equi-spaced measuring points on the foil ( 156 ) and the edge points were 38 mm away from the foil ( 156 ) side. The uniformity of copper deposits on the steel panel workpiece ( 102 ) surface was defined by the ratio of the standard deviation to the average copper thickness, expressed on a percent basis ((σ/ā)×100%), that is, the coefficient of variation (CoV)). The quantity σ is the standard deviation based on the measuring points; and ā is the mean thickness that is given by: ā=Σh i /n where n is the number of measuring points and h i is the copper thickness at each measuring point. For these experiments, n=36. The smaller the value of the CoV, the more uniformly is current distributed over the steel panel workpiece ( 102 ) surface, and the more uniformly is metal distributed over the steel panel workpiece ( 102 ) surface. The value of CoV for a conventional workpiece with dimensions of about 450 mm×600 mm in the electronics industry is about 10% to 12% although more typical values may be about 15%.
In this example the CoV value determined from analysis of the copper foil was 13.99%. The thickness of the copper deposit was measured with a micrometer.
Example 2
This example illustrates the use of the plating cell ( 100 ) to deposit copper uniformly onto a workpiece ( 102 ), to demonstrate the effects of the various attributes of the plating cell ( 100 ) of the present invention, such as flow rate of electrolyte through the eductors ( 116 ), anodes ( 112 ) to workpiece ( 102 ) distance, oscillation ( 154 ) of the workpiece ( 102 ), and vibration ( 152 ) of the workpiece ( 102 ).
The experiments were conducted in the plating cell ( 100 ) shown in FIGS. 10 to 12 . An acid copper sulfate electrolyte containing ˜97 g/L of CuSO 4 , 210-215 g/L of concentrated H 2 SO 4 , ˜63 ppm Cl − , and 350 ppm polyethylene glycol (PEG) was used as the copper electroplating bath for all experiments. The chloride/PEG is termed a suppressor and is not difficult to control. The plating bath does not contain difficult-to-monitor/control additives such as brighteners and/or levelers and hence we consider the bath as “additive-free.” The plating bath temperature was maintained in the range of 22 to 25° C.
The initial experiments for plating cell ( 100 ) characterization were conducted on a stainless steel panel (450 mm×600 mm), as a workpiece ( 102 ). The cell operating parameters, which were eductor ( 116 ) flow rate (low flow designates flow with a pump setting about one-half the maximum (high) flow), oscillation ( 154 ) frequency, vibration ( 152 ) frequency, and anode ( 112 ) to steel panel workpiece ( 102 ) distance, were selected as factors to evaluate the effect of plating cell ( 100 ) configuration on the current distribution over the panel workpiece ( 102 ) surface. The copper plating process was controlled by DC current at 25 A/ft 2 (provided by a PE86 dual output rectifier) to obtain a copper film with a thickness of about 25 micrometers. In all experiments, the anode chamber ( 126 ) was used, as was the porous fiber cloth ( 128 ), and 152 mm of anode non-conducting shielding ( 130 ).
After each test, copper foils ( 156 ) that plated on both sides of the stainless steel panel workpiece ( 102 ) were peeled off to analyze the copper thickness distribution. FIG. 13 illustrates the position of each measuring point ( 158 ) on the copper foil ( 156 ). There were thirty-six equi-spaced measuring points on the foil ( 156 ) and the edge points were 38 mm away from the foil ( 156 ) side. The uniformity of copper deposits on the steel panel workpiece ( 102 ) surface was defined as described in Example 1 above, with n=36 in this example also. The desired percentage value of CoV for the cell conditions in the electronics industry and more particularly printed circuit board industry for panels of approximately this size is less than 10%.
The experimental matrix, designed using a full factorial method, is listed in Table 1. MINITAB software was used to design the factorial method, although other methods could be used. The target performance criterion for the initial cell experimental study was to plate approximately 25 micrometers of copper over the steel panel workpiece ( 102 ) surface and evaluate the uniformity of copper thickness distribution. As shown in Table 1, a CoV of less than 10% was achieved under the plating cell operating conditions of Test 5 to Test 12, and the lowest CoV value was achieved in Test 5.
TABLE 1
Factorial Matrix and CoV Results for Example 2.
Test
Oscillation
Vibration
Distance*
CoV
No.
Flow
(cycles/min)
(cycles/min)
(mm)
(%)
1
High
26
0
290
12.11
2
High
12
0
290
12.55
3
High
12
1400
290
12.12
4
High
26
1400
290
12.35
5
High
26
1400
213
7.72
6
High
26
0
213
8.57
7
High
12
1400
213
9.54
8
High
12
0
213
9.19
9
Low
12
0
213
9.76
10
Low
12
1400
213
8.31
11
Low
26
1400
213
9.01
12
Low
26
0
213
9.54
13
Low
26
0
290
11.42
14
Low
26
1400
290
16.12
15
Low
12
1400
290
11.55
16
Low
12
0
290
11.13
*Distance refers to the anode-to-workpiece distance.
FIG. 14 shows a graph of the data from the factorial matrix. The graph plots the CoV versus the changes in each of the operating parameters and shows which operating parameter has the strongest influence on the uniformity of copper thickness across the surface of the stainless steel panel workpiece ( 102 ). FIG. 14 shows that the distance between the anodes ( 112 ), which controls the anode ( 112 ) to steel panel workpiece ( 102 ) distance, has the strongest influence on the uniformity of copper distribution over the steel panel workpiece ( 102 ), compared to the other parameters. However, one skilled in the art would recognize that oscillation and vibration may be important when the workpiece incorporates interconnects with fine pitch lines, through holes, vias and the like. These data would also indicate that even closer anode ( 112 ) to steel panel workpiece ( 102 ) spacing may offer further improvements in copper uniformity.
These observations are confirmed by the data in Table 1 which show that a more uniform copper thickness distribution (low CoV) can be obtained by using a closer distance between the anode chamber ( 126 ) and the stainless steel panel workpiece ( 102 ). The Test 5 plating cell configuration gave the most uniform copper thickness distribution over the steel panel workpiece ( 102 ) surface, with the closest anode ( 112 ) to steel panel workpiece ( 102 ) distance, at a high flow rate, high oscillation frequency and high vibration frequency.
Based on the test results shown in FIG. 14 , the effect of oscillation ( 154 ) and vibration ( 152 ) are unclear, although they suggest that higher vibration ( 152 ) and oscillation ( 154 ) frequencies will improve the uniformity of metal on the steel panel workpiece ( 102 ). The effects of oscillation ( 154 ) and vibration ( 152 ) might be seen more clearly on a patterned workpiece which has interconnect features such as fine pitch lines, through holes, and vias and the like.
Example 3
This example illustrates the use of the plating cell ( 100 ) to deposit copper uniformly onto a workpiece ( 102 ), to demonstrate further effects of the various attributes of the plating cell ( 100 ), such as flow rate of electrolyte through the eductors ( 116 ), anodes ( 112 ) to workpiece ( 102 ) distance, use of an anode chamber ( 126 ), use of a porous fiber cloth ( 128 ), use of additional non-conducting shielding ( 130 ), and use of a baffle ( 138 ) under the anode chamber, on the current distribution over the panel workpiece ( 102 ) surface.
The experiments were conducted in the plating cell ( 100 ) shown in FIGS. 10 to 12 . An acid copper sulfate electrolyte containing ˜97 g/L of CuSO 4 , 210-215 g/L of concentrated H 2 SO 4 , ˜63 ppm Cl − , and 350 ppm polyethylene glycol (PEG) was used as the copper electroplating bath for all experiments. The chloride/PEG acts as a suppressor and is not difficult to control. The plating bath does not contain difficult-to-monitor/control additives such as brighteners and/or levelers and hence we consider the bath as “additive-free.” The plating bath temperature was maintained in the range of 22 to 25° C.
The initial experiments for cell characterization were conducted on a stainless steel panel (450 mm×600 mm), as a workpiece ( 102 ). The copper plating process was controlled by DC current at 25 A/ft 2 (provided by a PE86 dual output rectifier) to obtain a copper film with a thickness of about 25 micrometers.
After each test, copper foils ( 156 ) that plated on both sides of the stainless steel panel workpiece ( 102 ) were peeled off to analyze the copper thickness distribution. FIG. 13 illustrates the position of each measuring point ( 158 ) on the copper foil ( 156 ). There were thirty-six equi-spaced measuring points on the foil ( 156 ) and the edge points were 38 mm away from the foil ( 156 ) side. The uniformity of copper deposits on the steel panel workpiece ( 102 ) surface was defined as described in Example 1 above, with n=36 in this example also. The desired percentage value of CoV for the cell conditions in the electronics and more particularly printed circuit board industry is less than 10%.
The experimental matrix and results are listed in Table 2. The target performance criterion for the experimental study was to plate approximately 25 micrometers of copper over the steel panel workpiece ( 102 ) surface and evaluate the uniformity of copper thickness distribution.
TABLE 2
Experimental Matrix and CoV Results for Example 3.
5C
Same as Test 5 but with 203 mm distance between
9.47
anode and panel
5D
Same as Test 5 but with 191 mm additional shielding
5.24
on top of anode chamber
5E
Same as Test 5 but no anode chamber in cell
14.81
SF
Same as Test 5 with anode chamber without fiber cloth
11.61
5CG
Test 5C conditions, adding baffle under the bottom
8.31
of each anode chamber
5DH
Test SD conditions, adding baffle under the bottom
5.18
of each anode chamber
5DI
Test 5D conditions with fiber cloth (did not dummy
5.45
the bath)
5DJ
Test 5D conditions with fiber cloth
5.39
11
Low flow, 26 cycles/min oscillation, 1400 cycles/min
9.01
vibration, 213 mm distance between anode center
and panel, anode chamber with fiber cloth, 152 mm
shielding on top of anode chamber.
11C
Same as Test 11 but low flow and 203 mm distance
10.06
between anode center and panel
11E
Same as Test 1.1 but low flow, no anode chamber in cell
14.11
Table 2 shows the effect of each plating cell attribute. Comparing Test 5 with 5C and Test 11 with 11C shows that decreasing the distance between the anode ( 112 ) and panel workpiece ( 102 ) from 213 to 203 mm decreased the uniformity (increased the CoV) of metal deposition across the steel panel workpiece ( 102 ). Comparing Test 5 with 5D shows that increasing the non-conducting shielding ( 130 ) at the top of the anode chamber ( 126 ) from 152 to 191 mm improved the uniformity (decreased the CoV) of metal deposition across the steel panel workpiece ( 102 ). Comparing Test 5 with 5E and Test 11 with 11E shows that removing the anode chambers ( 126 ) from the cell decreased the uniformity (increased the CoV) of metal deposition across the steel panel workpiece ( 102 ). Comparing Test 5 with 5F shows that removing the porous fiber cloth ( 128 ) from the anode chamber ( 126 ) decreased the uniformity (increased the CoV) of metal deposition across the steel panel workpiece ( 102 ). Comparing Test 5C with 5CG and Test 5D with 5DH shows that adding a baffle ( 138 ) under the bottom of each anode chamber ( 126 ) improved the uniformity (decreased the CoV) of metal deposition across the steel panel workpiece ( 102 ). Comparing Test 5D with SDI and 5DJ shows that changing the porous fiber cloth ( 128 ) to that of a different manufacturer decreased the uniformity (increased the CoV) of metal deposition across the steel panel workpiece ( 102 ). In summary, the best result was achieved in Test 5DH, which ran at high flow, 26 cycles/min oscillation, 1400 cycles/min vibration, 213 mm distance between anode ( 112 ) and steel panel workpiece ( 102 ), used an anode chamber ( 126 ) with a porous fiber cloth ( 128 ), had 191 mm non-conducting shielding ( 130 ) on top of the anode chamber ( 126 ), and had a baffle ( 138 ) attached below both anode chambers ( 126 ).
The invention having now been fully described, it should be understood that it might be embodied in other specific forms or variations without departing from its spirit or essential characteristics. Accordingly, the embodiments described above are to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are intended to be embraced therein.
REFERENCES
1 M. Paunovic and M. Schlesinger (2000), Modern Electroplating , Wiley Inc. NY.
2 M. Paunovic and M. Schlesinger (1998), Fundamentals of Electrochemical Deposition , Wiley Inc. NY.
3 Ward, M., D. R. Gabe and J. N. Crosby (1999a), Proc. European PCB Convention , Munich, Germany, November.
4 Serductor™ is a trademark of Serfilco, Northbrook, Ill.
5 Weber, A. (2003), The Importance of Plating Cell Design and Hydrodynamics for Repeatable Product Quality in Latest Generation Vertical Platers for the Galvanic Industry, IPC Printed Circuits Expo 2003, Long Beach, Calif.
6 Chin, D-T. and Tsang, C-H. (1978), Mass Transfer to an Impinging Jet Electrode, J. Electrochem. Soc., 125, 9, pp 1461-1470.
7 Hsuch, K-L. and D-T. Chin (1986a), Mass Transfer to a Cylindrical Surface from an Unsubmerged Impinging Jet, J. Electrochem. Soc., 133, 1, pp 75-81.
8 Hsuch, K-L. and D-T. Chin (1986b), Mass Transfer of a Submerged Impinging Jet on a Cylindrical Surface, J. Electrochem. Soc., 133, 9, pp 1845-1850.
9 Ward, M., D. R. Gabe, and J. N. Crosby (1998), Novel Agitation for PCB Production: Use of Eductor Technology, Trans IMF, 76, 4, pp 121-126.
10 Ward, M., D. R. Gabe, and J. N. Crosby (1999b), Exploitation of Eductor Agitation in Copper Electroplating, Proc. SURFIN/ 99, June 21-24, Cincinnati, Ohio.
11 Chin, D-T. and M. Agarwal (1991), Mass Transfer from an Oblique Impinging Slot Jet, J. Electrochem. Soc., 138, 9, pp 2643-2650.
12 Carano, M. (2003), Hole Preparation & Metallization of High Aspect Ratio, High Reliability Back Panels, Part-2, Circuitree , February, pp 10-22. | A method and apparatus for establishing more uniform deposition across one or more faces of a workpiece in an electroplating process. The apparatus employs eductors in conjunction with a flow dampener member and other measures to provide a more uniform current distribution and a more uniform metal deposit distribution as reflected in a coefficient of variability that is lower than conventional processes. | 2 |
TECHNICAL FIELD
[0001] This invention relates to fraud detection, and more specifically, to a method and apparatus for monitoring potential orders from consumers and making a determination as to whether any such potential order might be fraudulent. The invention has particular applicability in the processing of potential orders for new wireless service by a wireless network provider.
BACKGROUND OF THE INVENTION
[0002] Fraud detection in the use of credit cards and the purchase of items on-line is a significant problem. Often by the time the fraud is discovered, the consumer, credit company, or other entity may have already lost a significant sum of money, which sum may not be recoverable from the fraudster.
[0003] Fraudulent credit card use is most often controlled by simply “black listing” the credit card number. A legitimate user who loses his credit card, or has it stolen, reports the matter, and the credit card company shuts it off. However, in the telecommunications area, another type of fraud involves a user taking improper advantage of promotions offered by various wireless companies. Specifically, such wireless companies sometimes offer partially subsidized or even free wireless devices. In exchange, the consumer is required to sign up for a use plan for a prescribed time, say two years. The wireless provider assumes it will more than make up for the device subsidy due to the use fees that consumer will incur.
[0004] Fraudsters however, can cheat the system by ordering a large number of such subsidized wireless devices, and then reselling them individually to other consumers. Many, if not the majority, of such devices are then used on networks other than that operated by the entity selling the wireless device. Hence, another network provider receives the use revenue, and the provider actually supplying the wireless device does not make its expected revenue.
[0005] In view of the above, there exists a need to be able to detect fraudsters seeking to buy plural wireless devices as part of a promotional offering and then resell them in a manner that does not permit the entity offering the promotion to recoup its investment. Moreover, the invention has applicability in any type of sales where an initial item or service is provided at a subsidized cost, under the assumption that the subsidy will be recouped via future use. For purposes of explanation herein, we use the wireless telecommunications device example, although it is understood that the present invention is not limited thereto.
SUMMARY OF THE INVENTION
[0006] The above and other problems of the prior art are overcome in accordance with the present invention which relates to a method and apparatus for detecting potential fraudulent activity when a user is attempting to order wireless service. In one embodiment, a map of the total service area is divided into “population mapping areas”. A population mapping area is a predetermined area of the map, wherein one or more parameters have been assigned prescribed limits. In one embodiment, a population mapping area has an associated parameter representing the average number of orders for a given unit of time for new wireless service, wherein such value is calculated from empirical data. Population mapping areas may vary in size, location, shape, etc. The specified value may vary by time of day, year, specified holidays, etc.
[0007] Prior to completing any potential order, the service provider ascertains the location from which the order is originating and assigns the potential order to a selected population mapping area. If the potential order would cause one or more parameters associated with the population mapping area to be exceeded, then the system indicates that a fraud is suspected. If the parameter(s) are exceeded by too much, the system affirmatively indicates a fraud. Preferably, the generated indicators are visual indicators.
[0008] By visually displaying population mapping areas as a hierarchy, with some inside others, and by permitting a visual time lapse playback of all activity, fraud detection is visually enhanced.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0009] For purposes of explanation herein, we describe an exemplary embodiment of the invention wherein an order processing center for wireless service utilizes the teachings of an embodiment of the present invention. FIG. 1 shows a map of the United States, which preferably, in one embodiment of the present invention, is to be displayed on a computer monitor.
[0010] Internal to the computer is the population mapping areas. In one embodiment, each population mapping area is a zip code. In another, the map is divided into regions of equal area, and each is treated as a population mapping area. In other embodiments, the map is divided into areas of varying size and shape, based upon the service provider's ability to compile accurate data for any given area.
[0011] In a preferred embodiment, the population mapping areas are arranged as a hierarchy. Specifically, the areas of the map are divided as described above, and one or more such areas themselves are subdivided into other areas, which themselves may be subdivided. The hierarchy has a “top”, the major population mapping areas, as well as lower levels such as those described immediately prior hereto.
[0012] When an order is received, the system first assigns specific geographic coordinates to said order, such as an address, a latitude and longitude, etc. The coordinates are then determined to fall within a prescribed population mapping area. The system then ascertains a parameter of the assigned population mapping area, as if the potential order were included. For example, the system may determine that the population mapping area has had X number of orders within the past hour, even though it only averages ½ X orders per hour typically. This would exceed the prescribed threshold for the population mapping area. Other parameters may include, for example, the expected number of minutes of use originating from the population mapping area, which, when combined with data about average usage per device, would also indicate similar information as the foregoing example.
[0013] Preferably, a visual indicator is displayed on the map within the population mapping area wherein a threshold has been exceeded. In one embodiment, an overload value is also defined, and an additional visual indicator is displayed within the subject population mapping area when the threshold is exceeded by an additional amount equal to the overload value. Hence, for example, if the overload value is 30 percent, and the threshold is exceeded by nearly 100 percent, than 3 such visual indicators would be displayed within the population mapping area.
[0014] In one embodiment, the subject population mapping area may include sub-population mapping areas contained within it. In this case, the system can automatically determine, when a predetermined threshold is exceeded, which one of more of the sub population mapping areas within the population mapping area is the cause of the increased activity. Such a system would permit human intervention to permit fraud analysis and detection.
[0015] FIG. 1 depicts a map of the United States, showing by way of example that several population mapping areas each have several visual indicators. The foregoing may also be combined with “blacklisted” names or addresses to provide further detail and assistance in fraud detection. Specifically, once the visual icons indicate that a fraud is suspected, email addresses, phone numbers, or other identifying information of known fraudsters can be utilized to help determine if a particular fraudster is the culprit.
[0016] In one preferred embodiment, once a first population mapping area is determined to have too much activity, the system may scan the population mapping areas within the first population mapping area. This makes the analysis more granular to locate the actual population mapping area from where the fraud is originating. In another embodiment, once the first population mapping area from which the fraud may be originating is determined, the system can automatically provide a time lapse, replay of all of the activity within that population mapping area for the operator to review.
[0017] The order rate for any geographical area should remain relatively constant when presented as a ratio of devices ordered per unit of time divided by the population. Hence, even as the population expands, the order rates for a population mapping area should remain relatively constant.
[0018] Additionally, the system can maintain statistics on the average amount of ongoing usage for wireless devices within the population mapping area, as well as average use per device. If a number of wireless devices is ordered which would exceed an anticipated total usage, the system can conclude that some of the devices are not going to be used on the suppliers network, but are instead intended to be sold to others.
[0019] Any of the foregoing techniques can also be combined with other fraud detection techniques, even those of the prior art. The foregoing is by way of example only and is not intended to limit the claims. | A fraud detection methodology is disclosed wherein a map is divided into population mapping areas, and a level of normal legitimate activity for each area is calculated and stored. When activity levels indicate a possible fraud, visual indicators are displayed. The system may use a set of population mapping areas that are hierarchically arranged. | 6 |
BACKGROUND OF THE INVENTION
This invention relates to chain assemblies and pivot pins therefore and, more particularly, to a pivot pin assembly for chains and especially conveyor chains.
Conveyor chains, and especially those used in overhead conveyors typically include a center link with side links pivotally connected to each end of the center link by pivot pins. The center link is secured to a trolley bracket supported by trolley wheels on a rail. A sprocket or drive gear imparts movement to the chain for conveying suspended items along the rail.
One common prior known type of pivot pin used in such chain includes an integral, enlarged head at each end which retains the side and center links together along the pin. Such pins are inserted through enlarged apertures in the links and slid into their final position. In order to prevent disassembly of such "rivetless" chains, locking, non-rotational pins are used, i.e., pins with pin heads which are typically elongated and parallel to one another. The end of each center link is wider than its center portion. The pins are inserted through the three links, and rotated such that the elongated heads are received in recesses on the exterior sides of the side links. Extension or tightening of the chain causes the wider end of the center link to force the side links apart preventing the elongated heads from rotating out of their side link recesses.
Rivetless chain is expensive to manufacture because of required forging or machining of the pins and links, and the required tools and dies therefore. Also the elongated heads of the above-described pins prevent rotation, causing continuous wear of only one portion of the pin and reduced life or more frequent repair of the chain.
Certain chains with rotatable, wear compensating pins have also been proposed. Such pins typically include a cotter pin or other removable fastener retaining a washer at one end of the pin to hold the links in position. However, because of the constant motion, vibration and stress imposed on the conveyor chain as well as other industrial operations which occur in the environment in which conveyor chains are used, it has been found that such removable fasteners are often lost, broken or knocked loose resulting in chain disassembly, high maintenance costs, and frequent down time for conveyor lines.
The present invention was conceived as a solution to the above problems of wear, chain disassembly and pivot pin manufacture.
SUMMARY OF THE INVENTION
Accordingly, the present invention provides a pivot pin assembly, as well as a chain assembly using such a pivot pin assembly, which includes a removable fastener to retain a collar in place on the pin body or shaft. The collar is structured to protect and secure the removable fastener to prevent removal of the fastener and disassembly of the pin parts and the pin from the chain unless the chain is sufficiently relaxed and the fastener is manually removed. The pin assembly does not require the use of elongated, nonrotational, locking-type pin heads, thereby allowing pin rotation in the links for even distribution of wear around the entire pin when the pin is cylindrical. The pin and chain assembly cannot disassemble even under conditions of high load, stress or vibration or even if the chain or pin assembly is accidentally struck by another object. Moreover, even when the chain is relaxed the fastener must be manually removed before the chain can be disassembled.
In one embodiment, invention is a pivot pin assembly for chains including a pin having a pin body and first and second retaining means at spaced positions along the pin body for retaining chain links therebetween when such links are assembled over the pin body. One of the retaining means includes a collar which telescopes over one end of the pin body via an aperture in the collar. A removable securing means is secured to and extends outwardly from the pin body between the collar and the one end of the body over which the collar is telescoped. The collar includes a recess in its surface adjacent to the removable securing means, the recess being slightly larger than the securing means. When the collar is abutted against the securing means by chain links on the pin, the securing means are freely received in the recess. When the pin is cylindrical, the recess allows rotation of the collar around the pin body and securing means. The recess protects and prevents removal of the securing means unless the collar is slid away from them.
The pin assembly is adapted for use with a chain assembly including at least one center link having a pin receiving aperture adjacent each end. A pair of side links is included, each side link having an aperture therethrough at each end. The side links are received one on each side of the center link with the corresponding ends of the side links overlapping one end of the center link such that the apertures are aligned. Spacing means between each end of the center link and each of the side links are included to space the side links outwardly of the center link. A pivot pin assembly as described above is used to allow pivotal movement of the side links with respect to the center link. When the chain is extended, the spacing means forces the side links apart such that the collar is pushed outwardly and abuts the securing means. This results in the recess of the collar surrounding and protecting the securing means to prevent disassembly of the chain while the spacing means space the links apart.
In a preferred embodiment, the securing means is a split, annular, retaining ring received in an annular groove formed in the circumference of the pin body. The collar includes an annular recess which slip-fits closely over the retaining ring.
Various types of side and center links can be used with the pin assembly while various configurations of collars in the pin assembly can be used to facilitate chain articulation and pivotal movement. The spacing means is preferably a widened end of the center link. The preferred environment for this invention is in conveyor chains, especially of the overhead type.
The present invention provides numerous advantages over prior chain and chain pin assemblies, especially those for use with conveyors. The preferred retaining ring of the present invention is considerably stronger and more reliable than other removable fasteners. The securing means, such as the retaining ring, are protected against premature removal and the chain against premature disassembly by the surrounding recess of the collar. The collar cannot be removed from its protective position unless the chain is sufficiently relaxed and the side links are not spaced apart by the spacing means. Use of the present pin assembly eliminates the need for elongated, non-rotational, locking-type pin heads. Pin rotation and rotation of the collar on the pin can occur when the pin is cylindrical allowing even wear distribution around the pin. Chain disassembly is also prevented even when more than the normal amount of slack occurs in the chain of a conveyor line. Moreover, the present pin assembly is less expensive to manufacture than other pins and pin assemblies, while assembly, repair or replacement of the pins in a chain assembly remains simple.
These and other objects, advantages, purposes and features of the invention will become more apparent from a study of the following description taken in conjunction with the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a portion of a conveyor chain including the pin assembly of the present invention;
FIG. 2 is a fragmentary, sectional view of the chain assembly of FIG. 1;
FIG. 3 is an enlarged, fragmentary, sectional view of one end of the pin assembly of the present invention including area III of FIG. 2;
FIG. 4 is an enlarged, fragmentary, sectional view of a portion of a second embodiment of the pin assembly of the present invention taken in area IV of FIG. 7;
FIG. 5 is an exploded, perspective view of the pin assembly shown in FIGS. 1-3;
FIG. 6 is an end view of the collar used in the present pin assembly;
FIG. 7 is a fragmentary, sectional view of the pin assembly of the present invention in a second type of conveyor chain;
FIG. 8 is a fragmentary, sectional view of the pin assembly of the present invention in a third type of conveyor chain; and
FIG. 9 is a fragmentary, side elevation of the chain assembly shown in FIG. 8.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to the drawings in greater detail, FIG. 1 illustrates one embodiment 10 of a chain assembly including the present invention. Chain 10 includes forged, metallic center links 12 pivotally joined to identical pairs of side links 14. Each center link 12 is a continuous band of metal forming an elongated, continuous central aperture 16 extending entirely through the link and having rounded ends matching the diameter of the pivot pins received therethrough. The ends 18 of the center link are wider than the reduced width center portion 20 as is best seen in FIGS. 1 and 2. In fact, the widest portion of the center link corresponds to the center line of one of the pivot pin assemblies when that pin assembly is abutted against the end of the aperture 16 in center link 12. The end portions of the center link 12 on either side of the widest portion taper back and narrow to allow sufficient room and space for pivotal movement of the center link in the plane of the center line of the pivot pin with respect to the side links. Side links 14 are stamped or forged from planar sheet metal and include circular apertures 22 centered and extending therethrough at each rounded end. An elongated central aperture 24 is spaced between apertures 22 in the center of the link. Apertures 22 have diameters slightly larger than the pivot pins to allow rotation of the pins.
As will be seen from FIGS. 2, 3, 5 and 6, the first embodiment 25 of the pin assembly of the present invention includes three parts, namely, a pin 26, a collar 40 and a split, retaining band or ring 50. Pin 26 includes a cylindrical pin body 28 having an enlarged, circular head 30 formed integrally at one end of the pin body. Adjacent the opposite end 32 of the pin body is an annular groove 34 milled or cut in the circumference of the cylindrical pin body and having generally flat sides. Groove 34 is somewhat wider than the retaining ring 50 which it is designed to receive as explained below. End 32 is generally planar while the opposite end on the enlarged head 30 may be rounded as desired. In addition, the inner or under surface 36 of enlarged head 30 is beveled, chamfered or rounded to correspond to recesses in the links.
Collar 40 (FIGS. 3 and 6) is generally cylindrical with a cylindrical outer circumference, a generally flat or planar side surface 42, and a beveled, chamfered or conical opposite side surface 44. Aperture 46 extends centrally through the collar and has a diameter slightly larger than the outside diameter of the cylindrical pin body 28. The collar may thus be easily slid and telescoped over the cylindrical surface of the pin body and can rotate on the pin. Formed in the flat or planar outer side surface 42 of collar 40 is an annular recess 48 as best seen in FIG. 3. Recess 48 has a diameter only slightly larger than the outside diameter of retaining ring 50 such that the recess 48 may be easily slipped over the circumference of the retaining ring when the same is received in groove 34 and yet closely surrounds the ring. The free, slip fit of recess 48 over snap ring 50 also allows collar 42 to rotate about the pin body and ring without resistance.
The final portion of the pin assembly 25 is the split, retaining ring or band 50 comprising a partial, annular band of spring steel or the like having a cutaway sector 52 (FIG. 5). The inside diameter of ring 50 approximates the diameter of the bottom of annular groove 34. Cutaway sector 52 of the snap ring is smaller than the diameter of the bottom of groove 34 such that the snap ring must be slightly expanded to allow placement of the ring in groove 34. When released, however, the spring-like resilience of the ring 50 will retain it in place in the groove. In addition, in the preferred embodiment, the side surfaces of ring 50 are planar and match the flat sides of groove 34 to prevent any camming action between the groove and ring which might otherwise aid its unintended removal from the groove when side thrust is imposed on the ring when chain assembly 10 is in use. However, rings or bands and grooves with other cross-sectional shapes and other than flat sides such as circular could also be used.
As will now be understood from FIGS. 1 through 3, assembly of the chain 10 is accomplished by aligning apertures 22 in side links 14 with the central portion of aperture 16 of center link 12. Preferably, side links 14 are positioned generally perpendicular to the extended direction of elongation of center link 12 as shown in phantom in FIG. 1. Pin 26 is thereafter inserted through aligned apertures 22, 16, 22 until head 30 abuts one of the exterior side link surfaces. Collar 40 is telescoped over the opposite end 32 of pin 26 such that it is intermediate the opposite side link and groove 34 as shown in phantom in FIGS. 1 and 2. Snap ring 50 is thereafter expanded and seated in groove 34. Links 14 and center link 12 may then be moved in opposite directions such that pin 26 and side links 14 are moved to the end of apertures 16 in link 12. This movement causes the wider ends 18 of link 12 to urge side links 14 outwardly toward the ends of pin 26. The side link simultaneously forces collar 40 outwardly toward pin end 32. When pin 26 reaches its position at the end of aperture 16, the widest portion at end 18 of link 12 serves as a spacer which urges links 14 completely outwardly and collar 50 is entirely received within recess 48 as shown in FIGS. 2 and 3.
As also shown in FIGS. 2 and 3, the edges of apertures 22 on the exterior surface of side links 14 may be beveled or chamfered as shown at 23 to receive the conical or beveled surface 44 of collar 40 or the beveled, chamfered or conical inner surface of head 30. The mating receipt of the conical collar and enlarged head in the beveled recesses in the side links reduces the required overall length of the pin and facilitates articulation of the side links with respect to the pin and center link 12.
As will be understood from FIGS. 1 and 2, the circular configuration of the pin body 26, head 30 and collar 40 together with the loose, rotational fit of collar 40 on pin body 26 and of recess 48 around snap ring 50 allows rotation of the pin within apertures 22 and 16 during use of the conveyor chain. Such rotational movement distributes the wear caused by the links evenly around the pin and lengthens the life of the pin. In addition, the present pin assembly is stronger and more durable than prior known pin assemblies such as those using cotter pins and washers because the sheering stress in the direction of the axis of the pin which is necessary to break or sheer off snap ring 50 is tremendously greater than it is for a single cotter pin.
Referring now to FIG. 7, a second embodiment 60 of the chain assembly including the present invention is illustrated. Chain assembly 60 utilizes a plurality of identical, stamped chain links similar to those described and claimed in copending, commonly assigned U.S. patent application Ser. No. 897,400, filed on even date herewith, invented by Charles C. Frost, Edward D. Soberalski and Siegfried K. Weis, entitled CONVEYOR CHAIN WITH IDENTICAL LINK PARTS, the disclosure of which is hereby incorporated by reference herein. Each link part 62 in chain 60 is stamped from sheet metal and includes generally spherical or elongated, ridge-like, rounded protrusions 64 on one side at each end of each link and a corresponding, aligned recess 66 on the opposite side of each end of each link. The remaining areas of each link part 62 are generally planar. In the present embodiment, each link part 62 include a single, elongated aperture 68 having rounded ends matched to and a width slightly larger than the diameter of pin body 28 designed to be fitted therethrough.
As described in the above mentioned co-pending patent application and as shown in FIG. 7, a composite center link in chain 60 is formed from two of the identical link parts 62 placed back-to-back with their protrusions 64 extending outwardly, apertures 68 aligned and the links extending generally parallel to one another. Side links are formed by overlapping the ends of a spaced pair of identical link parts 62 with protrusions 64 extending inwardly and abutting and engaging projections 64 of the composite center link. A pin assembly 25 of the type described above is used to assemble the four identical link parts by passing the pin body 28 of pin 26 through the aligned apertures 68 of the link parts and assembling a collar 40 and snap ring 50 on the opposite free end of the pin in exactly the same manner as described above in connection with embodiment 10 in FIGS. 1-3, 5 and 6. During such assembly, the side link parts and pin 26 are moved to the reduced width center section of the composite center link, the pin inserted, and the side links and pin slid back toward one end of the aperture 68 in the composite center link. Such movement forces protrusions 64 against one another, thereby urging side link parts 62 outwardly and sliding collar 40 and recess 48 over snap ring 50 to protect and retain the same in place as described above. Protrusions 64 continue to space the links apart and maintain recess 48 over ring 50 during use of the chain. Chain 50 provides the manufacturing simplicity, cost advantages and articulation advantages fully described in connection with the above co-pending application Ser. No. 897,400. The beveled or rounded under surfaces of head 30 and collar 40 correspond well to the recesses 66 formed in link parts 62.
It is also shown in FIGS. 4 and 7, a slightly different embodiment 25' of the pivot pin assembly may be used with chain 60 or indeed chain 10 or any of the other chains described herein. Pin assembly 25' includes a pin body 28', a flat, enlarged head 30' and a flat collar or washer 40' telescoped over pin end 32' opposite flat head 30'. Collar 40' differs from collar 40 only in that both its side surfaces 42', 44' are generally flat, planar and parallel to one another. Recess 48' is similar to recess 48, is formed in surface 42' and functions exactly the same as recess 48 to protect and retain snap ring 50 in place on pin 28'. As will be seen in FIG. 7, however, the flat undersurface of enlarged head 30' and surface 44' of collar 40' engage corresponding flat, planar surfaces surrounding the end of aperture 68 on the exterior side surfaces of link parts 62 which form the side links in chain 60.
As shown in FIGS. 8 and 9, yet another embodiment 80 of a chain assembly using the present invention is illustrated. Chain assembly 80 includes a composite center link formed from identical link parts 62 of the type described above in connection with chain assembly 60. Link parts 62 are placed back-to-back in exactly the same manner to form an exactly similar composite center link as included in chain 60. However, chain 80 includes side links 82 having generally flat or planar side surfaces without any protrusions therealong as in chain 60. Side links 82 also include a pair of elongated apertures 84 having rounded ends and widths slightly larger than the diameter of pins 26, 26' adapted to be received therethrough to retain the links together. Apertures 84 extend from adjacent the rounded ends of links 82 toward the center or middle of these links to allow take-up of slack in the chain when the chain is relaxed. In addition, the end portions of apertures 84 adjacent the ends of the links may be recessed as at 86 (FIG. 8) to receive the beveled, chamfered or rounded undersurfaces of enlarged heads 30 of pins 26 or surfaces 44 of collars 40 as shown in FIG. 8. Apertures 84 could be circular if desired since the elongated center aperture in center links 62 allows assembly of the links, pin, collar and retaining ring as explained above. Again, either of the pin assemblies 25 or 25' may be used with chain 80 and assembly of side links 82 with the composite center link formed from identical link parts 62, including spacing protrusions 64 is accomplished in exactly the same manner as with chain embodiments 10 and 60 described above.
In each of the described chain embodiments 10, 60, and 80, the length of pin 26 or 26' is chosen to be sufficient to receive collar 40 or 40' and snap ring 50 and to provide a slight space or additional length between the adjacent surfaces of the side and center links at the position of the apertures or ends of the apertures in the side links and at the widest portion of the center link, i.e., at its ends. In fact, it has been found that a proper choice of dimension for the length of the pin is such that only one-third of the thickness of the snap ring will protrude from the recess 48 or 48' when the chain is laterally compressed. That is, when the chain is fully extended, the links are generally parallel to one another, the pin is received through the widest portion of the center link and at the ends of the respective apertures in all the various links, and the links and collar 40 or 40' are all compressed together and pushed along the pin toward pin head 30, the properly designed chain and pin length provides sufficient spacing to allow only one-third of the thickness of the snap ring 50 to extend out of recess 48 or 48'. Thus, even if such maximum lateral chain compression occurred during use of the conveyor, the recess 48 or 48' would maintain its protection and prevention of disassembly of the pin and chain assembly. Normally, however, the snap ring 50 is entirely received in the recess 48 or 48' which has a depth greater than the thickness of the snap ring for this purpose. In an actual tested embodiment of chain 10, the preferred dimensions for clearance between the side and center links is between 0.010 and 0.015 inches, the preferred thickness of the snap ring 50 is 0.0625 inches, and the preferred depth of the recess 48 or 48' is 0.010 to 0.0125 inches. Also, the thickness of side links 14 is preferably 0.25 inches, the widest portion of end 18 of center link 12 is preferably between about 0.730 and 0.755 inches, and the length of pin 26 is preferably between about 1.605 and 1.620 inches.
Pin assemblies 25, 25' are preferably formed from the standard steel or ferrous alloy metals used to form conventional conveyor chains. However, this invention will also be advantageous when formed from stainless steel or plastics and used in sanitary conveyor applications where frequent washing is encountered and resistence to corrosion is necessary.
Accordingly, the present invention provides an easily assembled, high strength, pin and chain assembly in which disassembly of the various parts is prevented and the securing means for the pin assembly is protected against damage and abrasion during use. While the above pin embodiments have been described with an integral head on one end of the pin, it is also possible to use a collar 40 or 40' and retaining band or ring 50 at each end of a straight pin to retain chain links together. Disassembly of the chain could then be accomplished from either end of the pin.
Although the preferred pin assemblies herein have been described with cylindrical pin bodies allowing pin rotation, other pin body shapes could be used such as oval, square, rectangular, hexagonal or the like. The apertures through the collars would normally correspond to the pin body shape. However, slightly oversize circular apertures in the collars would function adequately with such pin bodies if maintenance of collar rotation was desired. Similarly, the apertures through the side of center links could be matched to these other pin body shapes if pin rotation was not necessary or desired. Otherwise, circular or elongated apertures could still be used in the links. In each case, however, the collar would freely slip-fit over the pin body and retainer.
While several forms of the invention have been shown and described, other forms will now be apparent to those skilled in the art. Therefore, it will be understood that the embodiments shown in the drawings and described above are merely for illustrative purposes, and are not intended to limit the scope of the invention which is defined by the claims that follow. | A protective pivot pin assembly for chains, and especially conveyor chains, and a chain assembly incorporating that pin assembly. The pin includes a collar telescoped over one end and retained by a retaining ring or other securing member. The collar has a recess which receives the retaining ring therein when the collar is urged against the ring by chain links assembled on the pin. When extended, the combined widths and thicknesses of the links hold the collar over the ring to protect the ring and prevent removal of the ring and premature disassembly of the chain. When entirely relaxed, the chain may be collapsed, allowing the collar to be slid back and the ring to be manually removed. | 5 |
CROSS-REFERENCE TO RELATED APPLICATIONS
The subject matter of this application is related to that disclosed and claimed in concurrently-filed applications Ser. Nos. 923,527 and 923,526 of R. G. Young, the joint author of the present invention, which applications are assigned to the same assignee as the present application.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to electric discharge lamps and has particular reference to a compact fluorescent lamp unit adapted for use as a direct replacement for incandescent lamps in fixtures employed for residential and commercial lighting purposes.
2. Description of the Prior Art
Fluorescent lamp units having integral circuit and base components which permit the lamp unit to be screwed into and operated in a socket of a fixture that is designed for incandescent lamps are generally well-known in the art. An electrodeless fluorescent lamp assembly of this type that is energized by a high frequency voltage produced by a self-contained radio-frequency oscillator is disclosed in U.S. Pat. No. 3,521,120 granted July 21, 1970 to J. M. Anderson. Another fluorescent lamp unit which is designed for use in conventional light fixtures and has an envelope that contains concentric annular partitions and electrodes and is coupled to a screw-type base and a ballast component, starter and condenser which permit the lamp to be operated on an AC power supply is disclosed in U.S. Pat. No. 3,551,736 granted Dec. 29, 1970 to G. A. Doehner.
Fluorescent lamps that are designed for direct-current operation and have integral means for counteracting the cataphoretic "pumping" effect which causes the mercury vapor within the operating lamp to accumulate in the region around the cathode are also known in the art. A panel-shaped discharge lamp having partition members that are composed of porous ceramic or vitreous material (or which are provided with inserts of such material) that permit the mercury vapor to circulate within the envelope and between the partitions when the lamp is being operated on a DC power source is disclosed in U.S. Pat. No. 3,258,630 granted June 28, 1966 to W. J. Scott.
A gaseous discharge lamp unit of rectangular configuration in which two sections of straight glass tubing are joined together by U-shaped end members to form an envelope which contains a diaphragm that separates the electrodes but is permeable to mercury vapor and thus prevents the cataphoretic pumping of mercury vapor during DC operation is disclosed in German Patent Application No. 2,549,419 of A. Walz filed Nov. 4, 1975 and opened to inspection May 5, 1977.
Other types of fluorescent lamps that have partitioned envelopes or are provided with fillers or end plugs of glass wool or metal wool for various purposes are described in the following U.S. Pat. Nos.: U.S. Pat. No. 2,121,333 granted June 21, 1938 to Barclay, U.S. Pat. No. 3,024,383 granted Mar. 6, 1962 to Doering, U.S. Pat. No. Re. 22,896 granted July 8, 1947 to Polevitzky, U.S. Pat. No. 3,508,103 granted Apr. 21, 1970 to Young, U.S. Pat. No. 3,609,436 granted Sept. 28, 1971 to Campbell, U.S. Pat. No. 2,133,205 granted Oct. 11, 1938 to McCauley, and, U.S. Pat. No. 2,824,993 granted Feb. 25, 1958 to DeVriend et al.
SUMMARY OF THE INVENTION
While it has long been known in the prior art that the source brightness of a fluorescent lamp could be increased by using a partitioned envelope and that such lamps could then be combined with base and AC-circuit components to provide a screw-in lamp unit suitable for use as a replacement for incandescent lamps in various kinds of lighting fixtures, none of the prior art units combine a partitioned fluorescent lamp with a threaded base member and a circuit module that converts alternating current into direct current to provide a replacement lamp unit that is compact and can be operated in a DC mode in fixtures supplied with AC power. Such compactness and DC-operability are very important from a practical and commercial standpoint since they drastically reduce the radio-frequency noise and alleviate other interference problems encountered with AC circuits and radio-frequency power sources, but permit the lamp units to be used in lighting fixtures designed for incandescent lamps of small physical size without modifying the fixtures in any way.
Moveover, since fluorescent lamps for such direct-replacement markets must be of single-ended construction and have the electrodes located at the same end of the envelope, operating such a screw-in fluorescent lamp unit on direct current inherently created another problem which prevented such units from being commercially feasible and acceptable--namely, the problem of cataphoresis within the operating lamp that causes the mercury vapor to migrate toward and accumulate in the region around the cathode. The resulting "pumping" action lowered the mercury vapor pressure in the main portion of the discharge channel to a point that the arc was eventually extinguished.
All of the foregoing problems are solved in accordance with the present invention by providing a compact single-ended fluorescent lamp of tubular configuration with partition means and a diaphragm assembly that are so constructed that they define a tortuous discharge channel and permit the mercury vapor to pass freely from the cathode region to the anode region of the discharge channel around the partition, when the lamp is operated in a DC mode, without permitting the arc to follow the same path and thus bypass the partition. The diaphragm assembly meets this dual-function objective by means of a porous gasket that is permeable to mercury vapor but constitutes an impenetrable barrier to the arc discharge. This unique lamp is coupled to a screw-in type base component by a circuit module that is attached to the end of the lamp envelope and contains a miniaturized electronic circuit that converts an AC input into a DC output which is used to start and operate the lamp--thus providing a fluorescent lamp unit which has a high light output but is small enough to be used as a direct replacement in incandescent lighting fixtures.
The diaphragm assembly and its porous gasket component not only counteract the cataphoretic effect during DC operation but provide an additional manufacturing advantage since they permit water vapor and gaseous impurities to be evacuated from the lamp through the porous gasket when the lamp is being assembled and also permit the envelope to be quickly charged with a suitable starting gas and dosed with mercury in the usual manner.
BRIEF DESCRIPTION OF THE DRAWINGS
A better understanding of the invention will be obtained from the exemplary embodiments shown in the accompanying drawings, wherein:
FIG. 1 is an elevational view of a screw-in type fluorescent lamp unit having an integral DC-circuit module according to the invention;
FIG. 2 is an exploded perspective view of the fluorescent lamp and DC-circuit module and base components which comprise the lamp unit;
FIG. 3 is a schematic diagram of the preferred voltage-doubling circuit employed in the module showing the manner in which it is connected to the lamp electrodes and the threaded base member;
FIG. 4 is a pictorial view of the fluorescent lamp component shown in FIG. 1, parts of the lamp structure being removed to illustrate the diaphragm assembly at the sealed end of the envelope; and
FIG. 5 is a similar view of an alternative fluorescent lamp embodiment of single-ended construction having a modified form of diaphragm and porous gasket assembly.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
As shown in FIG. 1, the screw-in discharge lamp unit 10 of the present invention consists of three components, namely, a low-pressure electric discharge lamp L of single-ended construction, a module M that is coupled to the sealed end of the discharge lamp and contains the starting and operating circuit, and a suitable base component B which is attached to the circuit-module and is preferably of the threaded type and thus permits the lamp unit to be screwed into incandescent lamp sockets employed in various kinds of lighting fixtures. The lamp L is preferably of the fluorescent type and has a vitreous envelope 11 of tubular shape that contains a planar partition component 12 which defines a continuous discharge channel of tortuous configuration. The structural details of the lamp L will be described when the exemplary lamp embodiments shown in FIGS. 4 and 5 are discussed.
The circuit-module M contains a miniature electronic circuit which is designed to convert an AC voltage into a DC voltage which is applied to the lamp electrodes and thus energizes the lamp L when the threaded base B is screwed into the socket of an incandescent-lamp fixture and the latter is switched on. The module M is preferably releasably coupled to the lamp L by suitable connector means and the base component B can either be permanently attached or releasably secured to the module.
The coupling arrangement illustrated in FIG. 2 is preferred since it permits the fluorescent lamp L to be simply plugged into and withdrawn from the circuit-module M by means of two pairs of projecting contactors such as metal pins 13 which constitute the lamp terminals and are anchored in the end wall 14 of the envelope 12. The pins 13 releasably engage suitable sleeve or prong type contactors (not shown) in the circuit-module M and thus mechanically and electrically couple these two components together with the module seated against the sealed end of the envelope 12, as illustrated in FIG. 1. The base component B is permanently secured to the module M so that these two components form an integral assembly that can be screwed into the fixture socket and left in place--thus constituting a permanent part of the lighting fixture and converting it from an incandescent to a fluorescent type fixture. The fluorescent lamp L can then be simply removed when it reaches the end of its useful life and replaced with a new lamp that is plugged into the module-base assembly.
As will be noted in FIGS. 1 and 2, the voltage-converting circuit of the module M is enclosed within a suitable housing such as a cylindrical casing 16 of sheet metal or other durable material that preferably has a series of vent openings 17 in its side wall to permit the circulation of air through the module and maintain the circuit elements at a suitably low temperature during lamp operation. Additional vent openings 18 can be provided around the periphery of the bottom wall of the casing 16 if desired. The base member B is of the Edison type and consists of a threaded metal shell 19 that is fastened to the module casing 16 and is terminated by an end contact 20 that is anchored in an insulator 21 fastened to the end of the base shell. If desired, the casing 16 and base shell 19 can be extruded or otherwise formed from the same material as a single piece or member and the end contact 20 and insulator subsequently secured to the base shell portion 19.
As indicated schematically in FIG. 3, the lamp L contains a partition assembly 11 that extends longitudinally within the envelope 12 and defines a continuous U-shaped discharge channel. A pair of suitable thermoionic electrodes 22, 24 are located at the respective ends of the channel on opposite sides of the partition and the lamp contains an ionizable medium consisting of a fill gas (such as several Torr of argon) and a dose of mercury. While various kinds of AC to DC converting circuits may be employed to operate the discharge lamp L on direct current from an AC power source, a voltage-doubling circuit of the type shown in FIG. 3 is preferred.
As will be noted, the preferred electronic circuit consists of a pair of diodes 25, 26 that are connected by suitable conductors to a pair of capacitors 27 and 28 in such a manner that during one half-cycle of input AC voltage diode 25 conducts and charges capacitor 27 to full peak voltage, and on the other half-cycle of AC input diode 26 conducts and charges the other capacitor 28 to full peak voltage. Since the capacitors 27, 28 are in series, the resulting open circuit DC voltage across both capacitors is about 2.7 times the input rms voltage and, in the case of a 120 volt 60 Hertz AC power supply, produces approximately 324 volts DC. The DC output of the voltage-doubler circuit is applied to the lamp L by connecting capacitor 27 to one end of electrode 24 through a resistor 29, and capacitor 28 directly to one end of the other electrode 22. A suitable starting component S is connected to the other ends of the electrodes 22, 24 to supply preheat current to the electrodes in the well-known manner. Suitable conductors connect the base shell 19 with the diode network and the base end contact 20 with the capacitor network in the manner illustrated in FIG. 3, thus completing the circuit. A resistor 30 is preferably connected in parallel with the capacitors 27, 28 to insure that they are quickly and completely discharged when the power supply is switched off. As an additional safeguard, a suitable automatic protective component 31 such as a fuse or a thermal cut-out is connected in series with the diode-capacitor network to sense excessive-current operating conditions and open the circuit before any damage or hazardous situation occurs.
When the lamp unit 10 is energized, the DC output of the voltage-doubling circuit is applied to the lamp electrodes 22, 24 in series with the resistor 29 which thus serves as a ballast component and insures stable operation of the lamp L. As soon as the AC input voltage exceeds about 100 volts, the starter S opens and closes, alternatively heating the thermoionic electrodes 22, 24 and concurrently applying the DC output to the lamp L. In the aforementioned case of a 120 volt AC power supply where approximately 324 volts DC was developed by the circuit, this was sufficient to start an experimental "four pass" type partition lamp approximately 16 cms. long and 5.3 cms. in diameter within two seconds and operate it at a current of 330 ma and 67 volts DC with the voltage across the capacitors 27, 28 reduced to 92 volts.
As a specific example for those desiring to practice the invention, the voltage conversion circuit used to start and operate the aforesaid experimental partition lamp included a ballast resistor of approximately 75 ohms (wirewound type and 10 watt rating), a pair of 10 microfarad capacitors (preferably of the metallized polyester film type), and a pair of silicon diodes (1N4004 type) having a 400 peak reverse voltage rating and capable of carrying 30 amps peak surge current and 1 amp average half-wave rectified forward current. The starter S was an "FS-400" type marketed by Dura Corporation, Newark, N.J., and widely used and well known in the fluorescent lamp industry, and a 3 amp fuse was used as the protective component. The "bleeding" resistor 30 was a 0.47 megohm resistor of the carbon type having a 0.5 watt rating. The aforesaid components were of such size that they fit within a cylindrical casing approximately 7 cms. long and 5 cms. in diameter.
If desired, one or more of the circuit components can be mounted within the base shell 19 to reduce the size of the module M.
In accordance with the present invention, the cataphoretic "pumping" of mercury vapor and mercury ions during DC operation of the fluorescent lamp L, and the resulting accumulation of mercury vapor in the region of the cathode, is avoided by placing a suitable diaphragm assembly at the sealed end of the lamp envelope 11 which permits the mercury vapor to migrate from the cathode region to the anode region without permitting the arc to bypass the partition component 12. A compact tubular fluorescent lamp L that embodies this feature is shown in FIG. 4 and will now be described.
As will be noted, lamp L consists of a tubular glass envelope 11 that has a dome-shaped end and its inner surface coated with a layer 32 of a suitable ultraviolet-responsive phosphor. The partition component 12 has flanged side edges and consists of a sheet of relatively rigid material (such as glass, ceramic, fiberglass or a suitable sheet metal) that extends longitudinally within the envelope 11 and is also coated with a suitable ultraviolet-responsive phosphor 33. The end portion of the partition 12 is also flanged and is secured to a rigid septum or diaphragm assembly 34 that extends across the interior of the envelope 11 below the thermoionic coiled electrodes 22 and 24. The diaphragm 34 can be fabricated from a suitable non-conductive material (such as mica) or from sheet metal and has a series of ports or openings 35 along its periphery which provide passageways from one end of the discharge channel to the other and thus permits the mercury vapor to freely circulate within the cathode and anode regions of the lamp L and thus remain diffused throughout the envelope 11.
When the lamp is operated on DC, the arc is prevented from bypassing the partition 12 and jumping directly between the electrodes 22, 24 through the port openings 35 in the diaphragm 34 by providing the diaphragm with a peripheral flange 36 that snugly overlies and preferably engages the side walls of the envelope 12, and also by lining the diaphragm 34 with a porous body of suitable material which serves as a gasket 38 that is permeable to mercury vapor but is of sufficient thickness to constitute a barrier to the arc. While the porous gasket 38 can be fabricated from any suitable material (such as glass wool or quartz wool) that is electrically non-conductive and will not short-circuit the lead wires 40 which support the electrodes 22, 24 or contaminate the lamp, satisfactory results have been obtained by using a soft compliant pad made from interlocked ceramic fibers, such as a felt material composed of silica and alumina fibers that is marketed under the tradename "Fiberfrax" ceramic fiber by the Carborundum Company, Niagara Falls, N.Y. When this material is used, a gasket thickness of from about 1 to 6 millimeters is sufficient to provide the required degree of permeability for mercury vapor diffusion and envelope-evacuation purposes while still providing the necessary protection against arc penetration.
As will be noted in FIG. 4, the lead-in conductors 40 which support the electrodes 22, 24 are anchored in bosses 41 that constitute parts of the glass wafer-like stem 14 which is sealed to the end of the envelope 11 and forms its end wall. The wafer stem 14 is provided with a glass tubulation (not shown) through which the envelope 11 is evacuated during lamp manufacture and subsequently charged with a suitable fill gas (such as argon at approximately 4 Torr) and dosed with a measured quantity of mercury. The porous gasket component 38 of the diaphragm assembly 34 thus permits water vapor and gaseous impurities to be quickly evacuated from the envelope 11 through the port openings 35 in the diaphragm and insures that the envelope is substantially free of such contaminants before it is sealed.
If diaphragm 34 is made of sheet metal, as shown in FIG. 4, then suitable insulator bushings 39 of ceramic or the like are placed around the lead-in conductors 40 to prevent them from being short-circuited.
An alternative single-ended fluorescent lamp embodiment L a that is suitable for use in the compact lamp unit 10 is shown in FIG. 5. The same type of flanged partition assembly 12a and domed tubular envelope 11a are employed together with a pair of suitable thermionic electrodes 22a and 24a that are held in place by lead-in conductors 40a which are anchored in a wafer stem 14a, as in the previous embodiment. However, in accordance with this embodiment the diaphragm assembly 42 consists of a porous pad-like gasket 44 of soft compliant material (such as the aforementioned "Fiberfrax" ceramic fibers) that is held in place at the sealed end of the envelope 11a by a panel 46 of suitable non-conductive material (such as mica) that is seated on top of the stem bosses 41a. Accidental displacement of the gasket 44 toward the electrodes is prevented by a pair of generally semicircular retaining panels 47, 48 that are held in place on top of the gasket by metal tabs 49 which are welded or otherwise secured to the lead wires 40a. The retaining panels are so shaped and dimensioned that a slot 50 is provided to accommodate the non-flanged end edge of the partition 12a and permit it to be seated in nesting engagement with the gasket. Passageways for permitting diffusion of mercury vapor within the operating lamp and around both electrodes, and to facilitate evacuation of the envelope during lamp manufacture, is achieved by leaving portions of the porous gasket 44 exposed along the nested end edge of the partition 12a and around the periphery of the diaphragm assembly 42. If additional passageways are required or desired, then suitable port openings can be provided in the gasket-retaining panels 46, 47 and 48.
While a partition assembly consisting of a single planar member has been employed in the illustrated "two pass" lamp embodiments, it will be obvious to those skilled in the art that "four pass" and "six pass" lamps can also be made by using partition assemblies consisting of a plurality of planar members that are suitably shaped and arranged to provide a continuous discharge channel that traverses the envelope more than twice.
The phosphor material used to coat the partition and envelope components of the fluorescent lamp L is also not critical. However, excellent results from the standpoint of brightness, visual clarity and color-rendition have been obtained in test lamp units using a coating that contains a blend of three different phosphors which emit visible radiations in three different selected regions of the spectrum and provide a so-called "prime color" fluorescent lamp, pursuant to the teachings of W. A. Thornton in the article entitled "Luminosity and Color-Rendering Capability Of White Light", Journal of the Optical society of America, Vol. 61, No. 9, September 1971, p. 1155. The three-phosphor blend can, for example, consist of manganese-activated zinc silicate, europium-activated strontium chloroapatite and europium-activated yttrium oxide. | A single-ended fluorescent lamp having a partitioned envelope is coupled to a threaded screw-in type base and a module that contains a miniaturized electronic circuit which permits the lamp to be started and operated on direct current from an AC power source. The resulting compact fluorescent lamp unit can thus be used as a direct replacement for incandescent lamps in fixtures that are designed for residential and commercial lighting. Cataphoretic pumping and accumulation of the mercury vapor in the vicinity of the cathode during DC operation and short-circuiting of the partition by the arc discharge are both prevented by a diaphragm assembly at the electrode-end of the envelope which includes a porous gasket of fibrous material that is permeable to mercury vapor but constitutes an impenetrable barrier to the arc. The porous gasket also provides a manufacturing advantage since it establishes a connecting passageway between the tubulated sealed end of the envelope and the envelope proper which permits vapor and gaseous impurities to be quickly evacuated from the envelope before it is charged with fill gas, dosed with mercury and tipped-off. | 8 |
RELATED APPLICATION
[0001] This application claims priority from U.S. Provisional Application Serial Nos. 60/365,481 filed Mar. 19, 2002 and 60/366,475 filed on Mar. 20, 2002, the disclosures of which are incorporated herein by reference.
FIELD OF THE INVENTION
[0002] The present invention relates to a container made of a flexible material, erected from a unitary paperboard blank, for the holding, stacking and transporting of various items such as agricultural produce. In particular, the present invention relates to a container having tapered side walls and tapered stacking tabs extending from and co-planar with the tapered side walls, and locks scored and cut in a bottom panel of the container for accepting and securing the tapered stacking tabs of an adjacently stacked container.
BACKGROUND OF THE INVENTION
[0003] Corrugated paperboard is typically used in many different applications, for example, to form containers, boxes, cartons, or dividers for holding, storing, stacking or shipping various items such as agricultural produce.
[0004] Typically, such containers have a bottom and four side walls, and are formed from a blank scored with score lines or cut lines. The blanks are most often formed by automated machines in a continuous in-line process involving cutting, scoring and molding continuous sheets of paperboard. The paperboard is then folded along the score lines or cut lines to form a container. The blanks may be folded into a container by an automated machine or by a consumer.
[0005] During use, containers are often stacked on top of one another for ease of shipping and for optimum use of space. In these circumstances, it is possible for containers to have stacking tabs extending upward from the top edge of the container's side walls. These stacking tabs often fit into corresponding notches cut into an adjacently stacked container to help secure the stack. Since containers are usually stacked on top of like sized containers, the stacking tabs that extend upward from a lower container's side walls position directly into the side walls of a higher, adjacent container. Thus, to accommodate the lower container's tabs, a complimentary notch must be cut out of the higher container's side walls. However, a notch in a side wall is problematic in that it does not secure the stacking tab on all four sides. Thus, these sidewall notches do not fully prevent side-to-side movement, subjecting the stack to potential toppling. This is sometimes circumvented by having a multi-ply side wall, wherein a stacking tab extends upwards from an inner layer of the side wall, thereby aligning the stacking tabs with the bottom panel of an adjacent container as opposed to the side wall. This, however, required excess paperboard to be used to create the multi-layer side wall and related excess costs.
[0006] Further, it is easy to misplace a container during stacking such that a higher container falls into a lower container, usually on an angle, potentially damaging the contents of the lower container. To solve this, several prior art patents have devised tapered side walls, wherein the distance between the top edges of the side walls is less than the distance between the lower edges of the side walls. This eases stacking by severely limiting the probability of the higher container falling into a lower container, since the narrower upper portion creates a more functional ledge for the base of the higher container to rest on. However, with these containers, the tapered side walls do not have stacking tabs, severely lessening the strength of the stack.
[0007] Therefore, it is an object of this invention to provide a paperboard container with a stacking structure that has tapered side walls and stacking tabs that are secured by an adjacently stacked container on all four sides.
SUMMARY OF THE INVENTION
[0008] The present invention comprises a container preferably used for transporting food items, with a bottom panel, two opposing side walls, two opposing end walls and stacking tabs extending upwardly from either the end walls or side walls, co-planar to the side or end walls. The container's side walls or end walls are tapered, such that the angles between the side walls or end walls and the bottom panel is less than 90°. As a result, the tabs that extend co-planar from the end or side walls are likewise tapered at the same angle. The container further has locks scored and cut in the bottom panel of the container, wherein the tapered stacking tabs of the container extend through the cut slots of an adjacently stacked container.
[0009] The tapered side or end walls of the container and the corresponding tapered stacking tabs ensure that the stacking tabs fit into slots cut from the bottom panel, and not the side wall, of an adjacent stacking container, thereby allowing the containers to securely stack without requiring excess paperboard material. Further the tapered side walls lessen the distance between the top edges of the side or end walls as opposed to the base of the side or end walls, thereby preventing unwanted slippage by providing a better supporting ledge for a container when it is stacked on top of another. The combination of these features results in containers that are easy to stack and container stacks that are not prone to toppling, without using excess paperboard.
[0010] One embodiment of the invention includes locks, comprising of a cut out slot coupled to a flap, wherein the flap can bend upwards, thereby better accommodating a tapered stacking tab. Further, as stacking of adjacent containers is only possible if the pattern of the cut-out slots are configured in the same pattern as the stacking tabs, the locks are positioned to engage and lock the stacking tabs in a specific configuration. Therefore, the locks of the present invention can be scored and cut in any arrangement to fit on various arrangements of stacking tabs. For example, the bottom panel may contain four locks in a particular arrangement to accommodate four stacking tabs of a particular arrangement. Similarly, the locks may be inwardly spaced at different distances from an outer edge of the bottom panel to accept stacking tabs that are tapered at various angles.
[0011] Other embodiments include containers with reinforcement flaps made of flexible material such as paperboard. The resultant flaps lie flush against the upper sides of the container, thereby increasing the thickness of the upper sides and any stacking tabs extending upwardly therefrom. The reinforcement flap may also create a supporting ledge along the corners of the container. The supporting ledge and increased thickness of the stacking tabs further increases the strength of a stack and reduces the likelihood of a higher container falling into a lower container in the stack.
[0012] Other objects, embodiments, features and advantages of the present invention will be apparent when the description of a preferred embodiment of the invention is considered in conjunction with the annexed drawings, which should be construed in an illustrative and not limiting sense.
BRIEF DESCRIPTION OF THE FIGURES/DRAWINGS
[0013] [0013]FIG. 1 is a plan view of a container blank having tapered side walls and tapered stacking tabs extending co-planar therefrom.
[0014] [0014]FIG. 2 is a plan view of an alternate embodiment of a container blank having tapered side walls and tapered stacking tabs extending co-planar therefrom.
[0015] [0015]FIG. 3 is a plan view of an alternate embodiment of a container blank having tapered side walls and tapered stacking tabs extending co-planar therefrom.
[0016] [0016]FIG. 4 is a perspective view of the container blank of FIG. 3 folded and erected in a container.
DETAILED DESCRIPTION
[0017] A paper or paperboard blank scored in accordance with one embodiment of the invention is shown in FIG. 1. Blank 10 is scored for the purpose of folding into a clamshell container suitable for holding, shipping or stacking a wide variety of objects, such as perishable agricultural products. The blank is preferably a flat corrugated paper or paperboard made of any material known in the art that is suitable for the shipping and transporting of a wide variety of food items. For example, if one were to package heavier materials, a thicker grade may be advisable.
[0018] Bottom panel 12 is a substantially rectangular panel bordered by end fold lines 14 and side fold lines 16 . End panels 18 foldably connect to bottom panel 12 along fold lines 14 , and side panels 20 foldably connect to bottom panel 12 along fold lines 16 . Holes 22 are provided alongside fold lines 16 to provide breathing holes and access for an automated machine to manipulate and fold the blank into a fully erect container. Locks 24 are cut and scored in the bottom panel and may be adjacent score line 14 or inwardly spaced from score line 14 .
[0019] End panels 18 are generally rectangular panels that correspond to end walls when the container is fully erected. Accordingly, the length of end panels 18 in blank 10 corresponds to the height of the end wall 18 in an erected container. In the present example, the length of the end panel is 4¼ inches. However, the length of the panel, and corresponding height of the erected container, can vary widely within the scope of the invention. Each end panel 18 is bordered on four sides by an upper edge line 26 , fold line 14 , and two outer fold lines 28 . End flaps 30 foldably attach to each end panel along fold lines 28 . Stacking tab 32 extends outwardly from outer edge 26 , co-planar to side panel 18 .
[0020] End flaps 30 are substantially rectangular panels bordered on four sides by top edge 64 , side edge 66 , bottom edge 50 , and fold line 28 , wherein the bottom edge 50 of the panel extends laterally at a slightly different angle than the top edge 64 , thereby causing the end panel 18 to taper when the panel is erected. Bottom edge 50 extends generally in the same lateral plane as fold line 14 of end flap 18 , except it diverges with a slight angle toward the top edge 64 . The angle can vary greatly, depending on how much of a taper is ultimately desired in the end panel. In this embodiment, an angle of 1-5° is preferable. Similarly, top edge 64 exists largely in the same plane as top side 26 , except with a slight divergent angle away from bottom edge 50 . The angle of divergence of the top edge is ideally the same as the angle of divergence of the bottom edge. For example, if edge 50 diverges form fold line 14 at an angle of 3°, top edge 64 diverges from top 26 at an angle of 3°. The equivalent angle of divergence allows top edges 26 and 64 to create a flat, even top corner even as the end flap is tapered.
[0021] Each lock 24 on bottom panel 12 has a cut out slot 52 coupled with a flap 54 , wherein the slot is designed to engage and secure stacking tabs 32 of an adjacent container. To fully engage and accept a stacking tab that enters through cut slot 52 on an angle, flap 54 has the ability to bend upwards along a back cut line 56 . Flap 54 has a length, width and thickness, wherein the thickness is equal to the thickness of the bottom panel 12 , and the length and width can vary within the scope of the invention as long as the flap sufficiently engages a stacking tab. The flap is bordered by contact edge 58 , back cut line 56 , and side cut lines 60 and 62 . Contact edge 58 is the part of the flap that engages and holds secure stacking tabs 52 by rubbing against the tabs and holding them secure with a frictional force. Back cut line 56 is preferably a small cut line upon which flap 54 can pivot that extends parallel to contact edge 58 and perpendicular to side cuts 60 and 62 . However, the back cut line does not run the full length of contact edge 58 , instead being a smaller cut line intermediate side cuts 60 and 62 . In alternate embodiments, the back cut line is a perforated cut line that runs between side cuts 60 and 62 .
[0022] Cut lines 26 and 28 are incisions that extend laterally from the back of flap 54 to fold line 14 , parallel to each other and downwardly though the entire thickness of the panel 12 . The side wall incisions enable the flap to extend upward about the back cut line without encountering undue resistance from the part of bottom panel 12 that borders flap 54 .
[0023] Contact edge 58 extends from cut line 60 to cut line 62 parallel to fold line 14 , and engages tab 32 when is inserted through slot 52 , holding it securely in place. In the present embodiment, the top extension extends in a straight line. However, the shape of the extension may be altered in other embodiments. For example, extension 58 can extend in a slight, tongue shaped outward arc. In this circumstance, the outer most portion of the flap, or the portion that is furthest from the crease line, will be the part of the extension that contacts the stacking tabs.
[0024] Cut out slot 52 lies between flap 54 and fold line 14 , and is further bordered by side cuts 60 and 62 . The slot's width is great enough so that stacking tabs 32 can extend through the slot between the side cuts. However, the length between contact edge 58 and fold line 14 may be less than the thickness of the stacking tabs, enabling the tabs to press against a portion of flap 54 , causing the flap to bend upwards to accommodate the tab.
[0025] Each female slot member is aligned to accept a stacking tab on a slight taper. If the degree of taper changes, the alignment can change accordingly. For example, if side walls 18 taper a higher degree than shown in FIG. 1, the stacking tabs 32 will contact the bottom panel 12 of an adjacent container at some point closer to the center of bottom panel 12 . To account for this, the slots can be inwardly spaced from fold line 14 , thereby being aligned to accept the tabs.
[0026] Side panels 20 are generally rectangular panels each bordered on four sides by an upper edge 34 , lower fold line 16 , and side edges 42 . Side panels 20 correspond to the side walls when the container is fully erected. Accordingly, the length of side panels 20 (from fold line 16 to outer edge 34 ) in blank 10 corresponds to the height of the side walls of the erected container in FIG. 2. Ideally this height of side panel is the same as the height of the end panel 18 . In the present example the height is 4¼ inches.
[0027] The container is erected either manually or by an automated machine. Generally it is done with an automated machine, wherein bottom panel 12 is pushed downward, forcing end 18 and 20 to simultaneously fold upwards along fold lines 14 and 16 , respectively. End flaps 30 are then folded along fold lines 28 and are adhered to the outer surface of side panels 20 with a hot melt adhesive. When this happens, bottom edge 50 aligns with fold line 16 , pulling down end flap 30 and end flap 50 at an angle, thereby causing a taper in end panel 50 . The taper of the end panel may be slight, preferably between 1-5°, although this can vary widely within the scope of the invention depending on the angle of divergence of bottom edge 50 . The results of the taper is an angle less than 90° between bottom panel 12 and end panel 50 . The corresponding angle of the stacking tabs extending co-planar to the end panels vs. the bottom panel is therefore also less than 90°. In alternate embodiments, the end flaps can be adhere to the outer surface with another means, such as staples.
[0028] [0028]FIG. 2 shows an alternate embodiment, wherein the side walls and the corresponding stacking tabs on the side walls are tapered. Bottom panel 68 is a generally rectangular panel bordered on four sides by end fold lines 98 and side fold lines 100 . End panels 72 and side panels 78 and 94 are foldably connected to base panel 68 along fold lines 98 , 100 and 100 , respectively. Further, female notch members 76 partially extend into the base panel, traversing fold line 98 , and female slot members 102 are cut out of base panel and border fold lines 100 .
[0029] Side panel 78 is a generally rectangular panel that corresponds to at least one side wall when the container is fully erected. Accordingly, the length of side panels 78 in blank 70 corresponds to the height of the side wall when the container is erected. In the present example, the length of the side panel is 9{fraction (11/16)} inches, but the exact length can vary widely within the spirit of the invention. Each side panel 78 is bordered on four sides by an upper edge line 104 , lower fold line 100 , and two opposing side fold lines 106 . Side flaps 82 foldably attach to each side panel along fold lines 28 . One or multiple stacking tabs 80 extend outwardly from upper edge 104 , co-planar to side panel 78 .
[0030] Side flaps 82 function in largely the same manner as end flaps 30 on blank 10 in FIG. 1. Flaps 82 are substantially rectangular panels wherein bottom edge 110 and top edge 112 diverges at slight angles from the side wall, thereby causing the end panel 78 and corresponding stacking tabs 80 to taper when the panel is erected. Like flap 30 , bottom edge 110 extends generally in the same lateral plane as fold line 100 , except it diverges with a slight angle toward the top edge 112 . Likewise, top edge 112 exists largely in the same plane as upper edge line 104 , except with a divergent angle away from bottom edge 110 . The angle of divergence of the top edge is ideally the same as the angle of divergence of the bottom edge. This allows top edges 112 and 80 to create a flat, even top corner even when the side wall is tapered.
[0031] In FIG. 2, only one of the side walls includes stacking tabs integrally attached, extending co-planar from the top edge of the wall. The other side wall, side wall 94 , foldably connects to the base panel along fold line 100 and opposite to end flap 78 . Side wall 94 is a generally rectangular shape with a large, trapezoidal recess 116 providing side view visibility and breathing holes for the items held within. Side flaps 96 , which are foldably connected to side flaps 94 along fold lines 108 , function in the same way as side flaps 82 . However, the flaps need not be identical. For example, in FIG. 2, the angle of divergence of bottom line 118 is greater than the divergence of bottom line 110 . As a result, side panel 94 has a more severe taper than side wall 78 . However, the angle of divergence of bottom 118 can vary widely within the spirit of the invention. Further, end wall 94 may be replaced by an end wall substantially similar in configuration to end wall 78 . For example, side wall 94 may have stacking tabs extending co-planar from the top edge of the wall instead of recess 116 .
[0032] End panels 72 are generally rectangular panels that correspond to the end walls when the container is fully erected. Accordingly, the length of end panels 72 corresponds to the height of the end walls of the erected container. Ideally the height of side panel is similar to that of side walls 78 and 94 , although not necessarily identical. In the present example, the height is 9¾ inches. End panels 72 further comprise stacking tabs 74 extending co-planar from the end wall. The bottom of end panel 72 contains notches 76 , proportioned and positioned to engage and hold a stacking tab 74 of an adjacently stacked container. Neither end walls 72 nor the stacking tabs 74 are tapered.
[0033] Females member locks 102 in FIG. 2 are scored, cut and function much the same way as slots 24 in FIG. 1. Each lock 102 has a cut slot 88 coupled with a flap 84 , wherein the slot is designed engage and secure tapered stacking tabs 80 of an adjacent container. To fully engage and accept a tapered stacking tab, flap 84 has the ability to bend upwards along the back cut line 86 . Contact edge 90 engages and holds secure stacking tabs 52 by rubbing against the tabs, and holding it secure with a frictional force. In the present example, contact edge 90 is tongue shaped, with the center of the edge being closer to fold line 100 than the sides of the edge. Alternatively, the contact edge may run parallel to the fold line, like locks 24 in FIG. 1. Other embodiments include extensions of other shapes and arrangements, such as a concave arc.
[0034] Locks can be scored on one or both opposing sides of bottom panel 68 . FIG. 2 shows locks scored on opposing sides of the bottom panel. This is advantageous by allowing one container to stack on top of another even if the north-south orientation of a container is opposite from the adjacent container.
[0035] End wall 78 may further include a crushed area 92 that borders cut out slot 88 across fold line 100 , wherein the crushed area comprises a section of the end wall that is pressed to a point wherein the thickness of the crushed area is less than the thickness of the side wall. The crushed area allows easier access of a stacking tab 80 into a slot 102 of an adjacently stacked container in embodiments where the taper of end wall 80 is very slight.
[0036] Blank 70 is preferably erected in the same manner as blank 10 , through use of an automated machine that folds end panels 72 and side panels 78 and 94 upwards along fold lines, and adhering side panels 82 and 96 to the outer side of end panels 72 with a hot melt adhesive or other adhering means, such that edge 110 aligns with fold line 98 , causing a taper in the side walls.
[0037] A third embodiment of the container is seen in FIG. 3. Here, a reinforcement flap is added to the top of side wall 128 to reinforce the stacking tabs and to create a larger top ledge on the top edge of the side walls. The reinforcement flap is a long, thin band of flexible material similar in width to the side walls, but considerably shorter in length than the side walls. The flap further comprises small flaps 144 foldably attached along opposing fold lines 164 on the flaps opposing shorter ends, and at least one tab reinforcement 142 integrally attached to the flap along one of the longer ends.
[0038] Side wall 128 of FIG. 3 is similar to side wall 78 in FIG. 2. Specifically, tapered side wall 128 is bordered by a lower fold line 124 , two opposing end fold lines 136 , and an upper top edge 160 . Stacking tabs 140 extend outward from edge 160 , co-planar to end wall 128 . Side flaps 134 are foldably attached to side panel 128 along fold lines 136 , and have a bottom edge 130 that diverges from fold line 124 and a top edge 166 that diverges from upper edge 160 , wherein the angles of divergence is the same for top edge 166 and bottom edge 150 . In the embodiment shown, edge 150 has an increased taper over edge 50 and 110 of the prior embodiments. The amount of the increased taper, if any, can vary widely in the spirit of the invention.
[0039] Reinforcement tabs 142 foldably connect to the top edge of stacking tabs 140 along fold line 162 . When the container is erected, end panel 128 is folded upwards along fold line 124 . Reinforcement flap 138 is then folded downward along fold line 162 until the face of the reinforcement flap is flush against the top of the inner surface of panel 128 , as seen in FIG. 4. Small flaps 144 then partially fold along fold line 164 so that the small flap is diagonal to the corner of end flap 134 and side wall 136 . The diagonal corner creates an upper ledge that increases the sturdiness of a container stack by preventing a container higher in the stack from falling downward into a lower container.
[0040] The combination of stacking tab 140 and reinforcement tab 142 is a larger, thicker tapered stacking tab extending from the top side of the tapered side wall. To account for this additional thickness, the cut open slot 148 of lock 146 is wider to accommodate the larger, reinforced tab.
[0041] The remainder of the container blank in FIG. 3 is similar in function to that of FIG. 2. Additionally, however, side wall 130 may have one or more top reinforcement flaps 156 , wherein flap 156 is attached to wall 130 along perforated fold line 172 , and can fold over and lie flush against the inner surface of wall 130 . Top reinforcement flap 156 further has corner reinforcement 158 foldably attached along fold line 174 . The corner reinforcement folds along line 174 so that it is diagonal to the corner of side wall 130 and end wall 126 , mirroring small flaps 144 . The diagonal corner creates an upper ledge that increases the sturdiness of stacking container by preventing a container higher in the stack from falling downward into a lower container.
[0042] Side wall 130 further has side flaps 154 with a divergent bottom edge 176 and a diverging top edge 178 , resulting in a taper of side wall 130 when the container is erected. Side flaps 154 may also contain lengthened area 170 , which is a small extension of paperboard extending from top edge 178 , coplanar to flap 154 . The lengthened area 170 fits into corresponding notch 168 of an adjacently stacked container, as seen in FIG. 4. The notch is a recess in flap 154 positioned along bottom edge 176 , to engage and secure the lengthened area 170 .
[0043] In alternative embodiments, the side wall 130 may be replaced with a side wall similar to the side wall 128 of FIG. 3 or side wall 78 or 94 of FIG. 2, wherein the side walls are tapered and may have tapered stacking tabs extending co-planar therefrom, wherein the tabs fit into slots cut from the bottom panel, and not the side wall, of an adjacent stacking container.
[0044] Although the invention has been described with reference to preferred embodiments, it will be appreciated by one of ordinary skill in the art that numerous modifications are possible in light of the above disclosure. For example, the stacking tabs extending co-planar from the tapered end walls and side walls may be different shapes than the tabs depicted in the drawings without departing from the spirit of the invention. All such variations and modifications are intended to be within the scope and spirit of the invention as defined in the claims appended hereto. | A container for carrying produce having tapered side walls to aid stacking of like containers. The tapered side walls further have tapered stacking tabs extending outwardly from the top of the side walls, co-planar to the side walls. The tapered stacking tabs fit into slots cut-out of a bottom panel of an adjacently stacked container without necessitating cut outs in the side walls of an adjacently stacked container. | 1 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present Application is based on International Application No. PCT/EP2007/050048, filed on Jan. 3, 2007, which in turn corresponds to French Application No. 06/00030 filed on Jan. 3, 2006, and priority is hereby claimed under 35 USC §119 based on these applications. Each of these applications are hereby incorporated by reference in their entirety into the present application.
FIELD OF THE INVENTION
[0002] The invention relates to a method for managing data intended to be written to and read from a memory.
BACKGROUND OF THE INVENTION
[0003] Electronic systems requiring software generally need three types of remanent information for their operation: on the one hand programs and data accessible in read-only mode and on the other hand data accessible in read and write mode.
[0004] One solution consists in using memories of different types depending on whether the information has to be read only or whether the information has to be written, read and modified.
[0005] In the first case, read-only, use is made of fast programmable read-only memories, well known by the name “FlashPROM”. Memories of FlashPROM type are particularly well suited. These are very fast read-only memories allowing the storage of a large volume of information on a small surface area. These memories consume little electrical energy. This type of memory is organized into blocks called pages and, during operation, it is possible to erase the stored information only by erasing at least one entire page. It is not possible to erase just part of a page. Memories of FlashPROM type are not suited to the storage of data intended to be modified during operation when these data are of smaller size than the size of a page. Memories of FlashPROM type, the size of whose pages lies between 1 and 10 kilobytes, are easily obtained. It is therefore understood that this type of memory is not suitable for data of a few bytes and which is intended to be modified.
[0006] The invention is not concerned with the dynamic data customarily stored in a random-access memory well known by the name RAM. The invention is concerned with the data having a low occurrence of reading, writing and erasure. Logs of faults arising in an electronic system may be cited by way of example.
[0007] For such data, it is possible to use electrically erasable read-only memories well known by the name “EEPROM”. These are read-only memories allowing the storage, the erasure and the rewriting of individual data of variable sizes. Relative to memories of FlashPROM type, memories of EEPROM type are not as fast, have smaller capacity and consume more electrical energy.
SUMMARY OF THE INVENTION
[0008] The invention is aimed at allowing the storage of data of variable size that one wishes to read, write and erase or modify in a memory of FlashPROM type.
[0009] For this purpose, the subject of the invention is a method for managing data intended to be written to and read from a memory, characterized in that the memory is of FLASHPROM type organized into pages, in that several data are stored per page and in that it consists:
for each page, in reserving an area intended to receive the status and the number of the page, for each data item, in reserving an area for the status and the size of the data item.
[0012] The principle of the invention relies essentially on managing particular headers in the memory, headers for each page and for each data item within the pages.
[0013] The implementation of the invention makes it possible to dispense with the memory of EEPROM type by storing the data that it contains on another memory for example already partially used to store the program allowing the operation of an electronic system. Consequently, the invention makes it possible to reduce the number of components present in the electronic system and to reduce its electrical consumption.
[0014] Still other objects and advantages of the present invention will become readily apparent to those skilled in the art from the following detailed description, wherein the preferred embodiments of the invention are shown and described, simply by way of illustration of the best mode contemplated of carrying out the invention. As will be realized, the invention is capable of other and different embodiments, and its several details are capable of modifications in various obvious aspects, all without departing from the invention. Accordingly, the drawings and description thereof are to be regarded as illustrative in nature, and not as restrictive.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] The present invention is illustrated by way of example, and not by limitation, in the figures of the accompanying drawings, wherein elements having the same reference numeral designations represent like elements throughout and wherein:
[0016] FIG. 1 represents a header of a page of a memory of FlashPROM type;
[0017] FIG. 2 represents the structure of a data item intended to be stored on the page represented in FIG. 1 ;
[0018] FIG. 3 represents a flowchart for preparing a page;
[0019] FIG. 4 represents a flowchart for searching for an available page;
[0020] FIG. 5 represents a flowchart for searching for room available to write a new data item;
[0021] FIG. 6 represents a flowchart for detecting a full page;
[0022] FIG. 7 represents a flowchart for detecting a full memory;
[0023] FIG. 8 represents a flowchart for writing a data item;
[0024] FIG. 9 represents a flowchart for deleting a data item;
[0025] FIG. 10 represents a flowchart for reading a data item;
[0026] FIG. 11 represents a flowchart for defragmenting the memory;
[0027] FIG. 12 represents a flowchart for detecting a defragmentation in progress;
[0028] FIG. 13 represents a flowchart for verifying the consistency of the content of the memory;
DETAILED DESCRIPTION OF THE INVENTION
[0029] FIG. 1 represents a page of a memory of FlashPROM type in which the invention is implemented. As seen previously, only a part of the memory can be allocated to the storage of data. It is nevertheless considered that several pages of the memory are intended to receive data. At the start of each page envisaged for this purpose, an area of fixed size making it possible to receive the status and the number of the page is reserved. The status of each page can take a number N of values. A feature of the FlashPROM memory is the possibility of writing a value unitarily once. To modify or erase this value it is necessary to erase the whole of the page in which the value has been stored. To alleviate this difficulty, the N values follow one another sequentially and are coded on N-1 bits. For example, the status of the page takes the following five values: EMPTY, COPY, ERASURE, AVAILABLE, FULL. The meaning of these values will be seen subsequently. The values are coded on four bits. Advantageously a transition between two successive values is made by modifying a bit without erasure. On initializing the memory all the bits are for example set to 1 and the value “EMPTY” is therefore expressed as 1111. It is possible to modify this value which becomes COPY by modifying the last bit. COPY is therefore expressed as 1110. Thereafter the value becomes ERASURE by changing the penultimate bit so as to be expressed as 1100. Likewise AVAILABLE is expressed as 1000 and FULL is expressed as 0000.
[0030] Advantageously, the number of the page can be structured like the status so as to be able to be modified.
[0031] FIG. 2 represents the structure of a data item intended to be stored on the page represented in FIG. 1 . An area of fixed size making it possible to receive the status and the size of the data item is reserved at the start of the area making it possible to receive the data item. The status of the data item is managed in the same manner as that of the page. By way of example, the status of the data item takes for example the following four values: FREE, IN PROGRESS, OCCUPIED and DELETED. These four values are coded on three bits and follow one another sequentially. Subsequent to the size, an area making it possible to store the name of the data item may be provided. In the example given in FIG. 1 this name is formed of two items of information: type and number. Finally subsequent to the name of the data item an area is provided to receive the value of the data item.
[0032] FIG. 3 represents a flowchart for preparing a page. This flowchart is used during the first booting of the device containing the memory. The method modifies the status of each page allocated to the data item storage so as to place the value AVAILABLE therein, with the exception of the last page which will be used for the defragmentation of the memory. Moreover the method numbers the various pages chronologically. The status and the number of the page form the first two words of the page.
[0033] FIG. 4 represents a flowchart for searching for an available page by chronologically searching through the pages allocated to the storage of the data for the first page containing the word AVAILABLE.
[0034] FIG. 5 represents a flowchart for searching for room available to write a new data item. This search is made in the page selected with the aid of the flowchart of FIG. 4 . As seen previously, the pages are initialized by setting all the bits to 1. Taking the example described with the aid of FIG. 2 where the status of each data item can take four values and is therefore coded on three bits. The convention will be adopted that the value FREE is coded 111. The value FREE therefore represents the first location of the page that has not yet been used after initializing the page. The search is made by reading the status of each data item of the page by jumping the size of each data item. If the room available at the end of a page “B-A”, is less than the size “Size max data item” of the data item to be written, the page is declared full and the status of the page is modified, going from AVAILABLE to FULL by change of state of a bit of the status of the page.
[0035] FIG. 6 represents a flowchart for detecting a full page. It is possible to define an occupancy threshold not to be exceeded for each page whose status is AVAILABLE. The flowchart enables, as a supplement to that described in FIG. 5 , a page to be declared full.
[0036] FIG. 7 represents a flowchart for detecting a full memory. The memory is termed full if no further page includes the value AVAILABLE in its status.
[0037] FIG. 8 represents a flowchart for writing a data item at the location chosen. To make the writing of the object secure, the status of the data item is firstly modified, going from FREE to IN PROGRESS, by modifying a bit of the word containing its status. The name, the size and the value of the data item are written thereafter. Then the status is modified, becoming OCCUPIED, again by modifying a bit of the word containing the status. Thus, if a problem occurs while the writing of the data item is in progress, the status will retain the value IN PROGRESS, signifying that the data item has not terminated its writing phase and is therefore invalid. Alternatively, it is also possible to use the type information of the data item, illustrated in FIG. 2 , to be certain of the correct writing of the data item. The type takes for example a value “UNKNOWN” at the start of writing and is modified by changing a bit at the end of writing if the latter has been done correctly.
[0038] FIG. 9 represents a flowchart for deleting a data item. This algorithm is used as a function of the application if the value of a data item is modified. The FlashPROM memory not allowing the updating of a value, apart from the change of state of a bit in one direction only, if the value of a data item has to vary, the previous location of the data item is abandoned by modifying its status which becomes DELETED by modifying a bit of the word containing the status, and the new value of the data item is written at another available location by means of the flowchart of FIG. 8 .
[0039] FIG. 10 represents a flowchart for reading a valid data item. The valid data are those whose status is occupied. This flowchart returns all the valid data present in the memory by scanning all the pages containing data, pages whose status is AVAILABLE or FULL.
[0040] FIG. 11 represents a flowchart for defragmenting the memory. Specifically, as seen with the aid of FIG. 9 , a lapsed data item continues to occupy an area of the memory. The flowchart of FIG. 11 makes it possible to group the valid data together by eliminating the lapsed data, that whose status is DELETED. This flowchart uses the last page left free and whose status is EMPTY to copy over from a page whose status is FULL the valid data whose status is OCCUPIED, then the whole of the page whose status is FULL is erased, so becoming a new page reserved for defragmentation. More precisely, the status EMPTY is modified, becoming COPY. The number of the selected page whose status is FULL is modified with the number of the page whose status is COPY. The data whose status is OCCUPIED are copied over from the page whose status is FULL to the page whose status is COPY. The status COPY is modified to ERASURE. The whole of the page whose status is FULL is erased. Finally the status ERASURE is modified to AVAILABLE.
[0041] FIG. 12 represents a flowchart for detecting a defragmentation in progress. This flowchart is used when starting up a system operating with the method of the invention. This flowchart makes it possible to know whether a defragmentation has been interrupted during a system stop. A defragmentation is detected if the status of a page is COPY or ERASURE.
[0042] It is possible to avoid defragmentations while an operation is in progress and for example to impose a defragmentation at the start of an operation by defining a page occupancy threshold beyond which the status of a page goes from AVAILABLE to FULL. The occupancy threshold is defined so as to allow the storage of all the data written between two activations of the system.
[0043] To avoid the case in which the memory is full and defragmentation impossible through the absence of any lapsed data item, it is necessary to provide a sufficient number of memory pages to obtain a few lapsed data before total occupancy of the memory.
[0044] FIG. 13 represents a flowchart for verifying the consistency of the content of the memory. Each time the system is booted, the method verifies the consistency of the memory by deleting all the data whose type is UNKNOWN and by fixing their size, if the latter is not advised, at the maximum size of the data. This deletion is carried out by modifying the status of the data item, which becomes DELETED. The method orders a defragmentation if the memory is full or if it was in progress when the system was last deactivated. The method also erases the content of a page whose number would be identical to that of another page. This would be the case when a system deactivation occurs while preparing a page.
[0045] It will be readily seen by one of ordinary skill in the art that the present invention fulfils all of the objects set forth above. After reading the foregoing specification, one of ordinary skill in the art will be able to affect various changes, substitutions of equivalents and various aspects of the invention as broadly disclosed herein. It is therefore intended that the protection granted hereon be limited only by definition contained in the appended claims and equivalents thereof. | The invention relates to a method for managing data intended to be written to and read from a memory of FLASHPROM type organized into pages. Several data are stored per page and the method consists:
for each page, in reserving an area intended to receive the status and the number of the page, for each data item, in reserving an area for the status and the size of the data item.
Moreover, at least one page allowing the defragmentation of the memory is reserved. | 6 |
STATEMENT OF GOVERNMENT INTEREST
This invention was developed under Contract DE-AC04-94AL85000 between Sandia Corporation and the U.S. Department of Energy. The U.S. Government has certain rights in this invention.
TECHNICAL FIELD
The present invention is directed generally to electrical and electronic devices that exhibit resistive switching.
ART BACKGROUND
A memristor is a circuit element whose electrical resistance is determined by its previous current-voltage history in such a way that an applied voltage of sufficient magnitude can switch it between a high-conductance state and a low-conductance state. It is typically fabricated as a passive two-terminal resistive switching element in which a thin insulating film is sandwiched between two conductors. The insulating film is typically composed of a transition-metal oxide (TMO) containing mobile oxygen ions and oxygen vacancies. Typical TMOs used for this purpose are TiO 2 , Ta 2 O 5 , WO 3 , HfO 2 , NiO, and Nb 2 O 5 .
Memristors have also been referred to as “resistive random access memories,” abbreviated “ReRAMs” or “RRAMs”. A memcapacitor is an analogous device in which practical application is made of switched capacitance rather than resistance.
Relatively large signal voltages, typically greater than one volt, are used to change the resistive or capacitive state of the device, which can be read at low signal levels, typically less than one volt, without erasing the state of the device.
Although research on memcapacitors is still at an early stage, memristors have been extensively studied and have been proposed for the future replacement of flash memory and for other applications such as neuromorphic synapses. Memristors are especially promising for applications in low energy information storage because of their passive, non-volatile properties. By defining the low resistance state as “on,” and the high resistance state as “off”, each memristor can store one bit of digital information. There have also been proposals to store multiple bits in a single memristor element by switching the element among a multiplicity of states that include one or more states between “full on” and “full off”. For neuromorphic applications, a continuum of resistance states might be available, which could emulate the function of synapses in biological systems.
However, the practical realization of multi-bit and analog function has been hindered by the fact that much of the observed resistance change is significantly non-linear and occurs over a small fraction of the switching time. This makes it difficult to exert the needed amount of control over the tuning among different memory states. There is also a need to improve device-to-device reliability and reproducibility of memristors before they will be widely adopted into industry.
SUMMARY OF THE INVENTION
We have found a new approach to memristor design and fabrication that can provide greater control over the tuning of the resistance state of the device, and that can also improve device-to-device reliability and reproduceability. Applications of our new approach are not limited to memristors, but also include memcapacitors.
It is known that high-conductance filaments tend to grow within the thin insulating film. That is, the film behaves as an ionic conductor, within which filaments formed from oxygen vacancies or metallic ions grow from one electrode toward the other under stimulation by an applied voltage of sufficient strength. When as few as one filament bridges the gap between the electrodes, an electrical short can form across the insulating layer, thereby switching the element to a state of lower resistance.
As the leading end of a filament growing from one electrode gets closer to the opposite electrode, the electric field promoting its growth gets stronger. As a consequence, the few filaments that undergo the earliest initial growth will enjoy an increasing advantage as they continue to grow ahead of those behind them. This field magnification effect exacerbates small differences in the early growth of the various filaments and leads to high variability in the extent to which the various filaments have grown when the first filament has bridged the gap. If this effect can be suppressed, however, more uniform filamentary growth fronts can be achieved. This, in turn, affords greater control over the resistance tuning and greater uniformity among the individual elements that are produced from, e.g., a wafer-scale process.
We found that the field magnification effect can be suppressed by incorporating in the insulating layer between at least two sublayers having different ionic mobilities relative to the ions that contribute to filamentary growth. In embodiments, a plurality of such sublayers alternate between higher mobility and lower mobility compositions. In embodiments, the concentration of lower-mobility sublayers increases in the normal direction, i.e. along the direction of filamentary growth.
Accordingly, the invention in one embodiment involves apparatus comprising a resistive switching layer interposed between opposing electrodes, wherein the resistive switching layer comprises at least two sub-layers of switchable insulative material characterized by different ionic mobilities. In another embodiment, the invention involves a method for making a resistive switching device, comprising depositing a lower electrode layer on a substrate, forming over the lower electrode layer in contiguous sequence at least two sub-layers of switchable insulative material characterized by different ionic mobilities, and depositing an upper electrode layer over the sub-layers of switchable insulative material.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic drawing, in cross section, of a typical memristor structure, including an illustration of filamentary growth.
FIG. 2 schematically illustrates an illustrative embodiment of the present invention in which sublayers having different ionic mobilities are incorporated in the switching layer.
FIG. 3 is a graphical representation of the distribution of filamentary lengths as computed in a numerical simulation of a filamentary resistive switching event in a conventional memristor switching layer.
FIG. 4 is a graphical representation of the distribution of filamentary lengths as computed in a numerical simulation of a filamentary resistive switching event in a switching layer that is a matrix of multiple sublayers having different ionic mobilities.
FIG. 5 is a plot of resistance versus time during a resistive switching event, obtained from simulations of, respectively, a single-ionic-conductor memristor (upper curve) and a memristor having two different ionic conductors (lower curve).
FIG. 6 is a plot of capacitance versus time during a resistive switching event, obtained from simulations of, respectively, a single-ionic-conductor memristor (lower curve) and a memristor having two different ionic conductors (upper curve).
FIG. 7 is a schematic illustration of several possible sublayer distributions within the switching layer, which illustrate respective exemplary settings for the layer-position parameter that was used in our simulations.
FIG. 8 illustrates the result of calculations for optimizing a multilayer memristor design, in which the figure of merit to be optimized was the ratio of linear switching ranges, i.e., that portion of the resistive switching range for which the resistance state changes linearly in time under applied voltage for the multilayer memristor, relative to the same figure for the single-ionic-conductor memristor.
FIG. 9 illustrates the result of calculations for optimizing a multilayer memristor design, in which the figure of merit to be optimized was the ratio of capacitance switching ranges, computed in analogous fashion to the ratio of linear switching ranges of the preceding figure.
FIG. 10 illustrates the result of calculations for optimizing a multilayer memristor design, in which the figure of merit to be optimized was the ratio of relative standard deviations (RSDs) of the linear resistive switching range, i.e., the RSD (measured from ensemble calculations) of the linear resistive switching range for the multilayer memristor, relative to the same figure for the single-ionic-conductor memristor.
DETAILED DESCRIPTION
Two classes of memristors have garnered particular interest: the electrochemical mechanism class (ECM), and the valence change mechanism class (VCM). The resistance switching in both classes is driven by ionic transport through an insulating matrix under an applied electric field.
In the ECM class, an active electrode donates electrochemically active ions (e.g., Cu, Ni, or Ag) which are reduced and typically metalized once they diffuse to an opposing inert electrode (of, e.g., Pt or W). In VCM systems, oxygen vacancies are the mobile ions, which dope oxide layers resulting in higher local conductance.
FIG. 1 provides a schematic view of the basic structure of a filament-based memristor device.
As seen in FIG. 1 , electrodes 10 , 20 are separated by an electrical insulating layer 30 that is an ionic conductor. Within the insulating layer, high conductance filaments can form from oxygen vacancies (VCM) or metallic ions (ECM), all collectively referred to here as “ionic species”. In ECM memristors, the metallic ions may be donated by an active electrode, whereas in VCM memristors, both electrodes are passive, i.e., chemically inert.
When a voltage is applied between the top ( 10 ) and bottom ( 20 ) electrodes, mobile carriers drift through the insulating matrix under the electric field. Eventually, these carriers form the conductive filaments, which may eventually connect the electrodes resulting in a sharp reduction in resistance. Due to the stochastic nature of filament formation, these conductive filaments have random lengths and distributions. Filaments also grow at different rates due to natural variations in the local ionic conductivity of the insulating matrix.
Electric field strengths are higher (and thus growth rates tend to be faster) for longer filaments due to their closer proximity to the target electrode. Consequently, the field that drives the growth of a particular filament will tend to be amplified as the filament grows, causing small statistical fluctuations in filament growth early in the process to be magnified for longer filaments, which further increases their separation from shorter filaments.
The net result is a length distribution of filaments that is highly non-uniform, with one long filament that shorts between the electrodes and a large population of short filaments. This non-uniform conduction front of filaments results in devices with switching properties that strongly depend on random variations within the insulating matrix. Our design improvement is aimed at suppressing the field magnification effect.
Our approach is to incorporate layers of contrasting ionic mobility within the structure of the insulating layer, and by that means to suppress the field amplification and enhance the uniformity of filamentary growth. We believe that the low mobility layers will temporarily slow the growth of longer filaments, allowing shorter filaments to advance. Thus, the difference in filament lengths will be reduced, and because the accelerative effect of field amplification is suppressed, the shorter filaments will be able to maintain growth rates comparable to those of the longer filaments. By optimizing the thickness and spacing of the low mobility regions, we believe that the field-amplification effect can be substantially offset in at least some implementations.
Thus, for example, FIG. 2 provides a schematic view of a multilayered structure in which sublayers 51 , 52 of materials having two different ionic mobilities μ 1 , μ 2 respectively, have been incorporated in the switching layer.
Designs and fabrication sequences for conventional memristors are well known in the art and need not be described here in detail. Very briefly, a switching layer of, e.g., a TMO, typically tens to hundreds of nanometers in thickness, is enclosed between lower and upper metal electrodes. Without limitation, possible electrode materials include tungsten, aluminum, titanium nitride, gold, platinum, iridium, nickel, and tantalum. The various layers are deposited, e.g., on a silicon substrate that may be highly doped to provide back-side electrical contact. Memristors have been fabricated using conventional CMOS techniques. Thus, for example, the electrode layers and the switching layer may be deposited by sputtering. Other techniques that are readily available and may be useful for forming certain of the layers include, without limitation, reactive sputtering, chemical vapor deposition, and atomic layer deposition.
In a departure from conventional memristor fabrication techniques, our method includes the formation of sublayers that have different ionic mobilities. In implementations, the switching layer incorporates sublayers having two different ionic mobilities. The total number of sublayers may be as few as two, or there may be as many as ten sublayers, or even more. For at least some applications, switching layers that incorporate sublayers having even more than two different ionic mobilities may also be useful.
The specific technique used to form the various sublayers may depend, at least in part, on the thickness selected for those sublayers. Thus, for example, methods that might be appropriate for forming thicker layers include sputtering, molecular beam epitaxy, and atomic layer deposition, whereas preferable methods for forming thinner layers might include molecular beam epitaxy and atomic layer deposition. Of course, various combinations of growth techniques could be advantageous.
It may be advantageous to add an extended lower electrode layer consisting of insulator co-deposited with atoms of the same metal of which the lower electrode is composed. As is known in the art, such an extended layer can serve as a source of ions for filamentary growth. Although such layers in known implementations will feed the growth of one filament (or at most a few filaments), such a layer may be even more important as a source for the simultaneous growth of many filaments. For such purpose, it is desirable for the extended layer to be rich enough in electrode material to serve, effectively, as a non-depleting source. For example, using a silver lower electrode in a memristor having a single ionic mobility, we have used sputtering to co-deposit silver and silicon dioxide in extended layers about 50 nm thick. We found molecular ratios of silver to insulator in the range 1:2 to 1:8 to be effective, with a preferred ratio of 1:8. Another exemplary system for the extended layer is silver co-deposited with germanium selenide
Various known techniques may be applied, singly or in combination, to control the ionic mobilities in the respective sublayers. One such technique is to create sublayers whose microscopic structure contains defects in the form of interstitial atoms. An example is titanium dioxide with strontium interstitials. Another example is to vary the concentrations of grain boundaries in the respective sublayers. This can be done, e.g., by controlling growth parameters such as temperature and ambient pressure. Yet another example is to select alternating materials that have different annealing temperatures, so that grain boundaries may be selectively removed in one of the two ionic conductors via annealing, providing direct layer-selective tuning of ionic mobility.
The advantages of our new method are illustrated by the results of a set of numerical simulations that we performed. For a conventional switching layer and for a multi-layered switching layer as described here, we computed filament growth rates using local values for ionic mobilities and electric fields. We added a Gaussian distribution of local corrections to emulate irregularities such as grain boundaries, interstitials, and trapped charge.
Our simulation computed growth rates for one hundred independent filaments of respective lengths l n , n=1, . . . 100, where n=1:100) based on an activation model in which filament lengths increase as ions preferentially hop toward the filament tips under applied bias. The model is expressed by:
∂
l
∂
t
=
ⅆ
ω
(
ⅇ
-
qU
a
+
qVd
/
2
(
h
-
l
)
k
B
T
-
ⅇ
-
qU
a
-
qVd
/
2
(
h
-
l
)
k
B
T
)
(
1
a
)
∂
l
∂
t
=
μ
E
0
sin
h
(
E
E
0
)
(
1
b
)
In Eq. 1a, d is the hopping site distance, ω is the characteristic ion hop attempt frequency, U a is the activation potential, V is the applied voltage across the insulating matrix, h is the thickness of the device, l is the filament length, k B T represents the thermal energy, q is the ionic charge, and the second exponential term accounts for reverse hopping.
Equation 1b offers a conceptually simpler representation wherein the prefactors are combined into an effective mobility, μ=qωd 2 exp[−qU A /k B T]/k B T, and characteristic field, E 0 =2k B T/(qd)(E =V/(h−l)).
The large, non-physical hopping distances derived from activation models, d˜3 nm, have led some to suggest that linear ionic drift in an electric field may be more plausible. We therefore have repeated our simulations using a linear ionic drift model and obtained similar results.
The simulated filaments grow uniaxially through an ionic conducting medium in which the ionic mobility at each point is determined by a Gaussian distribution in order to emulate local irregularities such as grain boundaries, interstitial atoms, trapped charge, and other factors. The subscript i has been omitted from the equations to simplify the notation. It will be understood, however, that the variable l and the parameter μ are indexed by i.
As noted above, FIG. 2 provides a schematic view of a multilayered structure with materials having different ionic mobilities μ 1 , μ 2 . Two important factors in the simulations are the ratio of the layers' ionic mobilities and the spacing and arrangement of the layers in the z-dimension, i.e., along the axis normal to the substrate on which the layers are disposed.
FIG. 3 shows the filamentary length distribution, ordered from shortest to longest, in a modeled filamentary resistive switching event in the conventional layer. At such an event, the first filament or group of filaments has grown long enough to bridge the gap between the electrodes. At the switching event, we found a mean filament length of 40% of the device thickness, with a relative standard deviation of 45%. It should be noted that these values are not based on a single event, but rather resulted from averaging over an ensemble of starting conditions, each characterized by a random distribution of the local corrections mentioned above.
FIG. 4 represents a modeled filamentary resistive switching event in a switching layer that is a matrix of multiple sublayers as described here. Again, the filaments have been sorted by length in ascending order for clarity. In contrast to the conventional switching layer, we found that in an optimized design, the multilayer matrix yielded an average filament length that was 79% of the insulating matrix thickness, with a relative standard deviation of only 12%. Again, these values resulted from ensemble averaging as described above. The inset in the figure illustrates the approximate multi-layer design (layer number and position) used to obtain the optimized performance quoted above.
FIG. 5 is a plot of resistance versus time during a resistive switching event, obtained from simulations of, respectively, a single-ionic-conductor memristor (upper curve) and a memristor having two different ionic conductors (lower curve). The figure demonstrates that by using a multilayer matrix for the switching layer of a memristor, it is theoretically possible to increase the linear tuning range by as much as 75% or even more.
In the computations from which FIG. 5 was derived, resistance and time were both normalized to compare the linear tuning range of resistance for different device designs. The design parameters for this simulation were chosen to maximize the increase of linear tuning range as well as decrease the device-to-device variability. (The layer-thickness parameter was 20% of the device thickness; the layer-position parameter was 1.6. These parameters are explained in greater detail below.)
It should be noted in this regard that the achievement of a uniform conduction front not only affects the memristive properties of the device, but the memcapacitive properties as well. Thus, for example, FIG. 6 is a plot of capacitance versus time during a resistive switching event, obtained from simulations of, respectively, a single-ionic-conductor memristor (lower curve) and a memristor having two different ionic conductors (upper curve). The figure demonstrates that the range of capacitance values that is theoretically achievable using a multilayer matrix for the switching layer of a memristor is more than 400% larger than for a conventional, single-ionic-conductor memristor.
The simulated device performances illustrated above were achieved by optimizing three parameters: the sublayer thickness, the total number of sublayers, and a parameter that characterized the sublayer concentration profile, i.e., the number of sublayers per unit distance in the z-dimension. We took an approach in which concentration profiles of the form c(z)=z n , were modeled for a range of values of the exponent n. For each concentration profile, we investigated a phase space having the dimensions of layer position LP (each specified value of which, given a concentration profile, determines a spacing and concentration of all layers) and layer thickness δ.
A better understanding of the layer-position parameter LP is achieved with reference to FIG. 7 , which illustrates several example settings for the layer position. The rounded value of LP is an integer that specifies the number of layers of alternate ionic mobility that are incorporated in the switching layer. The remaining (positive or negative) fractional part of LP is an offset by which the sequence of layer positions is shifted along the layer profile. In the event that layers overlap, each resulting composite layer is treated as a single layer.
An exemplary optimization procedure begins by assuming the alternate mobility layers have equal thicknesses. The alternate mobility layer positions are mapped according to the generic power-law concentration profile c(z)=z n . (Similar results were obtained for most values of n such that |n|>1). The mapping rule specifies that for a total number NL of layers, the first layer is centered at the value of z where the integral of c(z) equals 1/NL, the second layer is centered where the integral equals 2/NL, etc.
FIGS. 8 , 9 , and 10 illustrate some of our optimization results, in which different figures of merit were optimized. In FIG. 8 , the figure of merit was the ratio of linear switching ranges, i.e., that portion of the resistive switching range for which the resistance state changes linearly in time under applied voltage for the multilayer memristor, relative to the same figure for the single-ionic-conductor memristor. In FIG. 9 , the figure of merit was the ratio of capacitance switching ranges, computed in analogous fashion to the ratio of linear switching ranges.
It will be understood from FIG. 8 that as the number of alternate ionic layers increases, the ionic mobility contrast decreases and approaches a single layer device. An optimal design is found between the two limits of single-layer devices of either ionic conductor.
In FIG. 10 , the figure of merit was the ratio of relative standard deviations (RSDs) of the linear resistive switching range, i.e., the RSD (measured from ensemble calculations) of the linear resistive switching range for the multilayer memristor, relative to the same figure for the single-ionic-conductor memristor. FIG. 10 demonstrates, in particular, a decrease in the theoretical variability of device performance using the multilayer design.
More specifically, to obtain the results shown in FIG. 10 , we simulated the switching of different devices by running multiple simulations (n=1000) with independent Gaussian distributions of local ionic conductivities in order to calculate the standard deviation of the range of resistance modulation for a large population of simulated device switchings. The standard deviation of the linear range of resistance was calculated. As FIG. 10 shows, the results predicted that the standard deviation could be reduced to as little as 10% of the variability observed in single layer devices (a 90% reduction).
With further reference to FIGS. 8-10 , we note that the pertinent figure of merit as displayed in FIG. 8 is greatest in a diagonal band beginning in the upper left-hand corner of the figure and extending in the direction of lower layer thickness and higher layer position; as displayed in FIG. 9 it is greatest in an island region near the lower left-hand corner of the figure; as displayed in FIG. 10 it is greatest in a diffuse band extending from a layer position of about 1 and a layer thickness of about 50 to a layer position of about 1.7 and a layer thickness of about 20. The pertinent figure of merit as displayed in FIG. 8 is least in the lower left-hand corner of the figure; as displayed in FIG. 9 it is least in the upper right-hand corner of the figure; as displayed in FIG. 10 it is least in a band extending from the upper left-hand corner of the figure to a layer position of about 1.2 and a layer thickness of zero.
It should be noted that the design phase-space contours are sensitive to the material properties of the ionic conductor layers, and that the characteristics of the alternate ionic conductor layers introduce additional potential design variables such as the ratios of ionic mobilities (μ 2 /μ 1 ), electronic resistivities (ρ 2 /ρ 1 ), and dielectric permittivities (ε 2 /ε 1 ) of the respective ionic conductor layers.
For the design phase spaces illustrated here, we used the following ratios: μ 2 /μ 1 =1/100, ρ 2 /ρ 1 =1/2, and ε 2 /ε 1 =1. Similar results were obtained for simulations with ρ 2 /ρ 1 =1. However, we chose a smaller value because ionic mobility correlates inversely with electronic conductivity. | A resistive switching device and methods for making the same are disclosed. In the above said device, a resistive switching layer is interposed between opposing electrodes. The resistive switching layer comprises at least two sub-layers of switchable insulative material characterized by different ionic mobilities. | 7 |
BACKGROUND OF THE INVENTION
[0001] The invention relates generally to a method of operating an electronic control unit of an automated mechanical transmission and more particularly to a method which simulates and provides a control signal indicating throttle kickdown.
[0002] In virtually all vehicles equipped with automatic transmissions, the action by the vehicle operator of depressing the accelerator pedal to the floor is interpreted by either the mechanical or electronic controls of the prime mover and transmission as a “kickdown” or “kickdown shift”: a desire to increase the speed and power of the prime mover and engage a lower gear in order to pass another vehicle or climb a grade. Depending upon the type of vehicle and transmission, such systems typically include mechanical linkages to the fuel or other engine systems and the transmission in the case of full mechanical systems and position sensors or switches wherein control of the engine and transmission are achieved through electronic, i.e., computer and software means in, for example, drive by wire systems.
[0003] In the latter case, switches activated by fully or substantially fully depressed accelerator or throttle pedals may be prone to failure but certainly require additional materials, wiring, engineering and design. Elimination of an on/off throttle position sensor therefore represents a reduction in engineering and component costs as well as an improvement in reliability.
BRIEF SUMMARY OF THE INVENTION
[0004] A method of operating an automated mechanical transmission includes a throttle position sensor and electronic control unit including software which provides a simulated signal in response to various full throttle positions and travel. Various time and positioned dependent relationships are sensed by a throttle position sensor and interpreted as a throttle kickdown by the electronic control unit which generates a kickdown signal. For example, in its least complex configuration, sensed travel beyond a predetermined threshold of 90% or 95% of full throttle pedal travel is interpreted as a kickdown request. A second criteria which may be combined with the above approach is to sense the speed of displacement (dT/dt) of the throttle pedal. Displacement speed above a predetermined threshold combined with 90% or 95% throttle displacement will generate a kickdown command. A third criteria is whether the throttle pedal maintains its 90% or 95% (or greater) position for a predetermined time period, e.g. 3, 5 or 10 seconds, or longer. A fourth criteria is whether the throttle pedal has been released such that it is below 10% of full travel and then satisfies other, above-recited criteria.
[0005] Thus, it is an object of the present invention to provide a throttle position sensor and software which simulates, by providing an output, when a driver has commanded a kickdown.
[0006] It is a still further object of the present invention to provide a sensor and software which simulates a driver kickdown command without utilizing a full travel two position, i.e., on-off sensor.
[0007] It is a still further object of the present invention to provide a proportional throttle sensor and electronic control unit which provides a kickdown signal to associated transmission control equipment.
[0008] It is a still further object of the present invention to provide a proportional throttle sensor and software which provides a kickdown signal to associated electronic equipment in response to various kickdown actions by the vehicle operator.
[0009] Further objects and advantages of the present invention will become apparent by reference to the following description of the preferred embodiment and appended drawings wherein like reference numbers refer to the same components, elements or features.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] FIG. 1 is a diagrammatic view of a conventional truck engine and transmission illustrating various operators and sensors;
[0011] FIG. 2 is a composite figure illustrating various throttle and sensor activity that may be interpreted as a kickdown request by the driver; and
[0012] FIG. 3 is a flow chart of software incorporating the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0013] Referring now to FIG. 1 , a diagrammatic view of a primer mover and automated mechanical transmission combination is illustrated and generally designated by the reference number 10 . The prime mover and automated transmission combination 10 includes an engine such as an internal combustion gas or Diesel engine 12 which is selectively coupled through a master friction clutch 14 to an automated mechanical transmission 16 . The automated mechanical transmission 16 typically includes a splitter or two range gear box at the head or input end of the transmission 16 , a three or four speed gear box driven by the output of the splitter and a two speed planetary gear assembly which drives an output shaft 18 .
[0014] The combination 10 also includes a microprocessor or electronic control unit (ECU) 20 which receives signals and data from various controls and sensors and controls the overall operation of the engine 12 , the master friction clutch 14 and the various sections of the transmission 16 . Specifically, the electronic control unit 20 is provided with data or input from the driver through sensors 22 such as the state of the ignition system, whether the transmission is to operate in automatic or manual mode and, in the latter case, provides commands regarding upshifts and downshifts. Additionally, specific driver input is provided by the throttle or accelerator pedal 24 which is coupled to and translates a linear and proportional or modulating throttle position transducer or sensor 26 which provides real time data to the electronic control unit 20 regarding the current position of the accelerator pedal 24 . The output of the sensor 26 may be a variable voltage, or coded signal or any other data stream compatible with and readily detected and read by the electronic control unit 20 . The current position signal from the throttle position sensor 26 may also be differentiated in the electronic control unit 20 to provide a speed of motion signal, i.e., derivative signals dT/dt, that is the change of position of the accelerator or throttle pedal 24 per unit of time.
[0015] Additionally, the electronic control unit 20 will typically receive a signal from an engine output shaft speed sensor 28 indicating the current rotational speed of the engine output shaft. An input shaft speed sensor 32 provides real time data to the electronic control unit 20 regarding the speed of rotation of the input shaft of the transmission 16 . Similarly, a transmission output shaft speed sensor 34 provides real time data regarding the rotational speed of the output shaft 18 of the transmission 16 .
[0016] Certain aspects and components of the engine 12 , clutch 14 and transmission 16 are under control of the electronic control unit 20 . For example, a fuel control assembly 42 adjusts the flow of fuel to the engine 12 in accordance with the position of the throttle 24 as indicated by the throttle position sensor 26 as well as various software, subroutines and algorithms which control overall operation of the engine 12 , the master friction clutch 14 and the transmission 16 . For example, during a gear change, fuel to the engine 12 may be reduced momentarily by the fuel control assembly 42 in order to assist synchronization of the engine output shaft and transmission input shaft in the newly selected gear. A clutch operator 44 receives an output signal from the electronic control unit 20 and engages and disengages the master friction clutch 14 . A shift operator and sensor assembly 46 includes a plurality of pneumatic, hydraulic or electric operators and associated linear translation sensors which first of all, engage and disengage various gear ratios in the various sections of the transmission 16 and provide data regarding the positions of such actuators to the electronic control unit 20 , respectively.
[0017] As noted above, rapid depression of the accelerator pedal 24 of essentially any vehicle equipped with an automatic transmission is interpreted by the transmission and associated components as a desire to rapidly accelerate the vehicle by increasing the speed of the engine 12 and downshifting the transmission 16 . The throttle position sensor 26 , as noted, provides a real time signal regarding the current position of the accelerator pedal 24 . Within the electronic control unit 20 , this position may be read as an actual measured distance, may be read and utilized as a percentage of travel from zero to one hundred percent, for example, or may be coded into any numerical or alphabetic data chain which is readily recognized and utilized by other components within the electronic control unit 20 to signify the actual position of the throttle pedal 24 .
[0018] Referring now to FIG. 2 , the electronic control unit 20 includes various software and algorithms which receive data regarding the real time position of the accelerator pedal 24 and the sensor 26 and command a downshift and engine acceleration in accordance with various software rules. At the top of FIG. 2 , a graph of operator controlled activity of the throttle 24 includes several events which are interpreted by the software as a desire or demand for a kickdown shift. Below the graph of throttle pedal position are five different graphs representing five different sensing and operating modes of the electronic control unit 20 which provide five different responses to the operator activity illustrated at the top of FIG. 2 .
[0019] Turning first to Graph A, this represents a kickdown signal which is generated solely by full or substantially full displacement of the accelerator or throttle pedal 24 . In order to ensure that a kickdown is commanded when the driver so intends, 95% travel of the accelerator pedal 24 and throttle position sensor 26 has been selected as the threshold for a throttle position only kickdown. Clearly, this 95% threshold can be adjusted to, for example 90% to accommodate and achieve slightly different design and operating parameters. Higher values raise the probability that they may not be exceeded due to linkage misadjustment, component wear or foreign objects lodged behind the throttle pedal 24 , thus impeding an intended kickdown. Lower values such as below 90% may cause a kickdown signal and associated activity to occur with less throttle travel than is generally desirable. It will be noted that Graph A is in the high or logic 1 position which requests a kickdown only during and always during periods that the position of the throttle 24 exceeds the 95% kickdown threshold.
[0020] Given certain vehicle component complements and diverse design and operating goals, it may be desirable to sense operating parameters in addition to just the position of the throttle 24 to affect or control the kickdown decision. Graph B illustrates such a first alternate operating mode. Here, both the 95% kickdown position threshold and speed of motion of the accelerator pedal 24 beyond a predetermined threshold must be satisfied in order for the electronic control unit 20 to generate a kickdown command. To the left in the throttle position graph is a steep gradient which, in combination with the 95% kickdown position threshold causes the electronic control unit 20 to generate a kickdown command as illustrated by the logic diagram which moves from zero or low to one or high when a sufficiently steep throttle position gradient (derivative) and the 95% kickdown position threshold are both exceeded. By way of comparison, note in the middle of the throttle position graph where a shallow gradient coupled with a throttle position exceeding the 95% kickdown threshold does not generate a kickdown signal from the electronic control unit 20 .
[0021] Another control alternative is illustrated in Graph C where the 95% accelerator pedal kickdown position threshold is combined with a timer or delay function which senses how long the accelerator pedal 24 has been depressed beyond the kickdown position threshold. The time t min is a short interval of time such as 2, 3, 5, 8, 10, 12 or 15 seconds or more or less which may be empirically or experimentally chosen and during which the accelerator pedal 24 must be maintained beyond the kickdown threshold in order to generate a kickdown signal. When the kickdown position threshold has been exceeded for a predetermined time, i.e., 3, 5 or 10 second timer has timed out, a kickdown signal is generated by the electronic control unit 20 .
[0022] It is also possible to combine the position, gradient (derivative) and timer or delay functions. This is represented in Graph D of FIG. 2 . Note that only the activity on the left side of the throttle position graph which includes a steep gradient or derivative, a final position exceeding the kickdown threshold and maintaining the throttle position beyond the kickdown position threshold for the minimum or reference time t min commands a kickdown shift.
[0023] A final Graph E presents an operating condition wherein the three requirements of curve D, throttle position beyond the threshold, gradient or derivative greater than a reference value throttle position beyond the threshold exceeding a reference or predetermined time period are combined with a reset threshold. The reset threshold senses whether the accelerator pedal 26 has been fully or substantially fully released and is, at least momentarily, in a substantially undepressed or unactivated state. Once again for purposes of ensuring good data, the reset threshold is not set at 0% travel but is a value between 5 and 15% and preferably about 10%. Thus, only when the throttle pedal 24 has been released or substantially released and then followed by a gradient or derivative beyond the threshold, a final position beyond the kickdown threshold and a final position beyond the kickdown threshold which is maintained at least for the minimum time period will a kickdown signal be generated by the electronic control unit.
[0024] Referring now to FIG. 3 , a computer program or software flow chart illustrating a subroutine for the various operating modes or configurations presented in FIG. 2 is illustrated in FIG. 3 . The software subroutine 50 starts with an initializing step 52 which clears all registers and commences the iterative cycle of the subroutine 50 anew. A first decision point 54 inquires whether the throttle reset function is enabled. This is the additional step appearing in Graph E at the bottom of FIG. 2 . If the throttle reset function is enabled, the decision point 54 is exited at YES and the program 50 moves to a second decision point 56 which inquires whether the throttle position has fallen below a minimum position such as the 10% threshold illustrated in Graph E of FIG. 2 . If the throttle position has not been below the minimum or reset position during this cycle, the decision point 56 is exited at NO and the program 50 concludes at an end point 58 to be repeated in accordance with the iteration time commanded by the executive system of the electronic control unit 50 .
[0025] Returning to the decision point 54 , if the throttle reset function has not been enabled, which applies to Graphs A, B, C and D, the decision point 54 is exited at NO and the program moves to a decision point 62 . Likewise, if the throttle position has fallen below the minimum throttle position, the decision point 56 is exited at YES. In both instances, the program 50 enters a decision point 62 which inquires whether the gradient function is enabled. This function appears in the Graphs B and D. If the gradient function is enabled, the program moves to a decision point 64 which inquires whether the gradient or derivative dT/dt is greater than the gradient or derivative reference value. If it is not, the decision point 64 is exited at NO and the program 50 returns to its end point 58 . If the gradient or derivative is larger than the reference value, the decision point 64 is exited YES and the program 50 moves to a decision point 66 . Similarly, if the gradient function is not enabled, the decision point 62 is exited at NO and the program 50 also moves to the decision point 66 .
[0026] The decision point 66 inquires whether the throttle position has exceeded the maximum throttle value, 95% of the throttle travel as illustrated in FIG. 2 . Note that there is no throttle position enabled inquiry because each and every simulated kickdown operational mode illustrated in FIG. 2 utilizes and senses actual throttle position. Thus, if throttle position has not exceeded the 95% threshold, the decision point 66 is exited at NO and the program ends at the end point 58 . If the throttle position has exceeded the maximum or threshold value, the decision point 66 is exited at YES and the program 50 enters a decision point 68 which inquires whether the timer or delayed time function is enabled. If it is not, the decision point 68 is exited at NO and the program 50 issues a kickdown command in the process step 70 . If the timer function is enabled, the decision point 68 is exited at YES and the program 50 moves to a decision point 72 that inquires whether the time the accelerator pedal 24 has exceeded the kickdown threshold is greater than the delay or reference time. If it is not, the decision point 72 is exited at NO and the program ends at step 58 . If the time is greater than the reference time, a decision point 72 is exited at YES and a kickdown signal is generated at step 70 .
[0027] The entire process in the program 50 is illustrated in Graph E. If the throttle reset function is not enabled, the gradient function is not enabled and the throttle position and timer function are utilized, the operation is presented in Graph C. If the throttle reset function is not enabled but the gradient function and the throttle position are utilized, this is represented by Graph B. If the throttle reset function and the gradient function are not enabled but the throttle position is utilized with the enabled timer function, this operational mode is presented in Graph C. If all of the optional functions are disabled, that is, the throttle reset function, the gradient function and the timer function, the throttle position exceeding the kickdown threshold generates a kickdown signal and this is presented in Graph A.
[0028] Upon the generation of a kickdown signal or command by satisfying one of the sets of conditions presented in Graphs A, B, C, D or E of FIG. 2 , the electronic control unit 20 will typically proceed to command and execute a one, two or more gear downshift by issuing appropriate commands to the fuel control 42 , the clutch operator 44 and the shift operator and sensor assembly 46 in accordance with its established programs and subroutines. It will be appreciated that these programs and subroutines may be the same or similar to programs and subroutines previously utilized with a prior art mechanical switch activated by full throttle depression.
[0029] It will also be appreciated that an electronically generated or simulated kickdown signal or command for an automated mechanical transmission provides numerous benefits. First of all, this configuration eliminates a mechanically actuated switch which may be prone to failure. More importantly, however, the data from the throttle position sensor 26 may be utilized through the electronic control unit 20 to institute or command downshifts based upon several operating conditions as well as diverse values of such operating conditions as illustrated in FIG. 2 .
[0030] The foregoing disclosure is the best mode devised by the inventor for practicing this invention. It is apparent, however, that methods incorporating modifications and variations will be obvious to one skilled in the art of motor vehicle clutches and lubrication thereof. Inasmuch as the foregoing disclosure is intended to enable one skilled in the pertinent art to practice the instant invention, it should not be construed to be limited thereby but should be construed to include such aforementioned obvious variations and be limited only by the spirit and scope of the following claims. | Across the spectrum of automatic transmissions, rapidly depressing the accelerator pedal to floor is interpreted by the transmission and associated components as a request for increased engine power to, for example, pass another vehicle or climb a hill. A method of operating an automated mechanical transmission includes a throttle position sensor and electronic control unit and provides a simulated signal in response to various full throttle positions and travel. Various time and position dependent relationships such as substantially fully depressed throttle, rapidly depressed throttle, throttle maintained substantially fully depressed and throttle substantially fully released before being depressed, i.e., a “pumped” throttle are sensed by the throttle position sensor and interpreted as a throttle kickdown by the electronic control unit which generates a kickdown signal. | 8 |
CROSS REFERENCE TO RELATED APPLICATIONS
This application is a continuation of application Ser. No. 10/076,111 filed Feb. 15, 2002.
This application claims the priority of German Application No. 101 07 282.1 filed Feb. 16, 2001, which is incorporated herein by reference.
BACKGROUND OF THE INVENTION
This invention relates to a device and method for detecting lightweight waste such as short fibers, dust, fiber fragments, fly and the like in a carding machine. Such waste is released from the fiber material while being processed by a clothed fiber processing roll. The waste is carried away in a suction conduit containing a filter.
In a known apparatus, such as disclosed, for example, in German Patent No. 34 29 024 the dust and dirt content of the fiber material is measured. The fiber material is advanced by a feeding device to an opening roll which cooperates with a dust separating opening provided with a sieve-like surface adjoined by a filtering unit which, as viewed in the direction of the flow of the suction stream, comprises a sieve for short fibers and fly and a dust filter. After performing a test, the proportion of dust (at the dust filter) and short fibers (at the sieve) may be determined by measurements. It is a disadvantage of such a prior art arrangement that the degree of the intensity of fiber opening performed by the opening roll remains unchanged. It is a further drawback that the measuring and evaluating steps are intermittent which is a structurally complex solution.
SUMMARY OF THE INVENTION
It is an object of the invention to provide an improved device and method of the above-outlined type from which the discussed disadvantages are eliminated and which, in particular, make possible a continuous determination of the fiber damages as a result of the degree of aggressiveness of the carding operation.
This object and others to become apparent as the specification progresses, are accomplished by the invention, according to which, briefly stated, the carding machine includes clothed rolls for processing and carrying fiber material thereon; an arrangement for separating lightweight waste from the fiber material processed by the clothed rolls; a conduit for receiving the lightweight waste; an air stream generating arrangement for generating an air flow in the conduit for removing the lightweight waste; an adjusting device for varying a degree of carding intensity of the carding machine; and a detecting device for measuring quantities of the lightweight waste produced at a respective degree of carding intensity.
By virtue of the invention, the degree of fiber damage to the carded fiber material (aggressiveness of carding) can be continuously (on-line) determined. It is a particular advantage of the invention that the degree of fiber damage in a given carding operation, as concerns the quantity of light waste, may be compared with measured values for the damaged fiber in case of gentle carding and in case of aggressive carding and to derive an optimal setting for the carding process from these findings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic side elevational view of a carding machine incorporating the invention.
FIG. 2 is a schematic side elevational view of the sliver output region of the carding machine showing suction devices for removing lightweight fiber waste.
FIG. 3 a is a schematic side elevational view of a measuring device for lightweight fiber waste.
FIG. 3 b is a schematic end elevational detail of the construction shown in FIG. 3 a.
FIG. 3 c is a diagram showing the dependency of differential pressures from the setting of the carding degree.
FIG. 4 a is a schematic side elevational view of traveling flats of a carding machine showing a circumferentially shiftable slide guide in a first position.
FIG. 4 b is a view similar to FIG. 4 a showing the slide guide in a second position.
FIG. 5 is a schematic side elevational view of a device for circumferentially shifting a slide guide.
FIG. 6 is block diagram of an electronic control and regulating device.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 shows a carding machine CM which may be a high-performance DK 903 model manufactured by Trützschler GmbH & Co. KG, Mönchengladbach, Germany. The carding machine CM has a feed roller 1 , a feed table 2 cooperating with the feed roller 1 , licker-ins 3 a , 3 b , 3 c , a main carding cylinder 4 having a rotary axis M, a doffer 5 , a stripping roll 6 , crushing rolls 7 , 8 , a web guiding element 9 , a sliver trumpet 10 , calender rolls 11 , 12 , a traveling flats assembly 13 having flat bars 14 , a sliver coiler 16 depositing sliver into a coiler can 15 . The processing direction of the fiber material through the carding machine CM is designated with the arrow K.
FIG. 2 shows a web guiding element 9 which may be, for example, a WEBSPEED model manufactured by Trützschler GmbH & Co. KG. The web guiding element 9 has an advance trumpet 9 a preceded by a web-supporting element 9 b , as viewed in the direction of material advance. Between the advance trumpet 9 a and the sliver trumpet 10 an air gap is present through which lightweight fiber waste exits and is removed by suction via a suction conduit 9 c . The fiber material F is taken off the doffer 5 by the stripping roll 6 and is introduced via a web-supporting and guiding element 19 into the nip defined between the cooperating crushing rolls 7 , 8 . The fiber material exiting the crushing rolls 7 , 8 is backed up by the supporting element 9 b and introduced in the inlet opening of the advance trumpet 9 a . The fiber material then passes through the advance trumpet 9 a and the sliver trumpet 10 and is withdrawn therefrom by calender rolls 11 , 12 as a fiber sliver. In the region above the fiber material F, between the nip defined by the crushing rolls 7 , 8 and the inlet of the advance trumpet 9 a a further suction conduit 18 is provided for removing the lightweight fiber material.
Turning to FIGS. 3 a and 3 b , the lightweight waste-carrying conduit 9 c has a branch conduit 20 for carrying the lightweight waste G in the direction D. In the conduit 20 a measuring device MD is disposed. In the upstream branching location of the conduit 20 a switch 21 is provided which includes a pivotal gate 22 for selectively directing the waste material from the conduit 9 c either into the conduit 20 or into the conduit 39 which bypasses the measuring device MD and which is connected to a filter device of the carding machine. The downstream end of the conduit 20 is connected to a suction source such as a fan 23 .
The measuring device MD comprises a filter assembly having a filter carrier disk 24 traversing the conduit 20 and rotated by a motor 36 about an axis 36 a extending parallel to the longitudinal axis of the conduit 20 . The filter assembly further has two filter elements 25 I and 25 II which are pervious to the air stream generated by the suction source 23 but which retain thereon the fiber waste G. The filter elements 25 I and 25 II are mounted in a diametrically opposite relationship on the carrier disk 24 . Also referring to FIG. 3 b , when the active, waste-laden filter element 25 I is to be replaced, the disk 24 is rotated in the direction of the arrow C. As a result, the filter element 25 I is moved from its operative position depicted in FIG. 3 a into a cleaning position which is externally of the conduit 20 and which is in alignment with a cleaning device 41 , such as a suction arrangement. At the same time, the filter element 25 II previously purged of the waste by the cleaning device 41 , is moved into the operative position in the path of the stream flowing in the conduit 20 .
Inside the conduit 20 , upstream and downstream of the filter disk 24 , respective pressure sensors 37 a and 37 b are disposed. A differential pressure measuring device 38 generates a signal which represents the difference between the pressures measured by the sensors 37 a , 37 b upstream and downstream of the filter disk 24 . The differential pressure measuring device 38 is connected to an electronic control and regulating device 33 (FIG. 6) which has a memory for receiving data relating to the function between the differential pressures and the quantity of the lightweight fiber waste G adhering to the filter 25 . At a given nominal pressure difference, the motor 36 rotates the filter disk 24 to thus move the filter 25 I into alignment with the cleaning device 41 . A rotation of the filter disk 24 can also be initiated after a predetermined delay.
FIG. 3 c illustrates the above-described differential pressures measured in Pa units for an empty filter, represented by bar 42 , a waste-laden filter at a gentle carding, represented by bar 43 and a waste-laden filter at an aggressive carding, represented by bar 44 .
FIGS. 4 a and 4 b show a device for adjusting the carding clearance between the clothings of the flat bars 14 , on the one hand, and the clothing of the carding cylinder 4 , on the other hand. The extent of such a clearance determines the degree of carding intensity. The adjusting device of FIGS. 4 a and 4 b comprises a slide guide 30 which is slightly wedge-shaped as viewed in the circumferential direction. As related to the cylinder axis M (shown in FIG. 1 but not shown in FIGS. 4 a and 4 b ), the slide guide 30 has an outer surface which, when viewed circumferentially, is throughout concentric with the cylinder axis M, that is, its radius r 1 is constant. The underside of the slide guide 30 has, as viewed in the circumferential direction A, a changing radius r 4 . The slide guide 30 is shiftable on an arcuate supporting surface of a flexible bend 17 . The supporting surface of the flexible bend 17 has a circumferentially changing radius r 3 . As a result of a circumferential displacement of the slide guide 30 , the radius r 1 of the slide guide surface changes, whereupon the flat bars 14 which glide on the slide surface of the slide guide 30 change their distance from the cylinder 4 , thus changing the degree of carding intensity. It is seen that the position of the slide guide 30 depicted in FIG. 4 b has been shifted in the direction of the arrow A with respect to the position shown in FIG. 4 a.
Turning to FIG. 5, on the slide guide 30 a carrier element 26 is arranged which is coupled with a toothed rack 27 a . The latter, in turn, meshes with a gear 27 b which is rotatable in the direction O, P. The gear 27 b is driven by a reversible motor 28 , whereby the slide guide 30 is shiftable circumferentially in the direction of the arrows A, B. The motor 28 is connected with an inputting device 29 with which a very small carding clearance, for example, {fraction (3/1000)} inch may be set as a nominal value. The setting of the carding clearance may also be effected by an electronic control and regulating device 33 (FIG. 6) with a nominal value memory and/or inputting device. The above-described adjustment of the radius of a slide surface of a slide guide by circumferentially shifting the slide guide is described in further detail in U.S. Pat. No. 5,918,349.
When a small carding clearance is set by the mechanism shown in FIGS. 4 a , 4 b and 5 , a more aggressive carding results with an increased proportion in lightweight fiber waste G. Conversely, in case the carding clearance is enlarged (such a position is illustrated in FIG. 4 b ), a less aggressive, gentle carding results with a smaller proportion of lightweight fiber waste G. As illustrated in FIG. 3 c , a relationship exists between the extent of charging the filter 25 with lightweight fiber waste G and the carding process based on the setting of the carding clearance.
FIG. 6 shows a block diagram of an electronic control system which has a control and regulating device 33 , for example, a microcomputer, connected to an inputting device 34 for the desired carding clearance, the drive motor 28 , a display device 40 , a further inputting device 29 , a switch 35 for the motor 36 and the differential pressure measuring device 38 .
In the description which follows, short fiber content, dust and fiber fragments, that is, lightweight fiber waste, are hereafter collectively designated as KSF. During the carding process, the difference between the fiber sparing (gentle) carding and the aggressive (more damaging) carding manifests itself particularly in the changed short fiber fly proportion, the degree of exiting dust and the extent of fiber fragments released to the environment when the sliver is mechanically stressed (release of KSF parts). The released KSF parts which form only one part of the totality of KSF parts in the sliver, are proportionate to the KSF parts remaining in the material (assuming a constant room and material climate). By virtue of the fact that according to the invention the released KSF quantities are captured by vacuum means, it is feasible to describe the degree of fiber damaging, that is, the degree carding.
The mechanical stress on the fiber material (sliver) appears after the carding process in the region of doffing. In this connection particularly two locations are of importance, namely, the position above the web guiding element 9 and the position above the advance trumpet 9 a preceding the trumpet 10 . A meaningful reference magnitude is obtained by relating everything to the KSF quantity which is released in case of a non-aggressive (gentle) carding. If it is desired to additionally describe the entire carding range by means of KFS quantities, then the KFS quantities for an extremely aggressive (damaging) card setting are also detected. For changing the carding intensity the carding clearance is automatically adjusted as explained earlier in connection with FIGS. 4 a , 4 b and 5 .
First, the KFS quantity is deliberately removed by suction and directed to the active filter 25 I or 25 II of the measuring device MD. After a defined time period the pressure at locations upstream and downstream of the active filter is determined from which the pressure difference AP is obtained. Such a pressure difference is proportional to the KFS quantity. If the pressure difference in case of non-aggressive carding is set to 0%, the degree of the aggressiveness of all other carding processes may be expressed in percentage with which the degree of carding may be described on-line.
Measuring of the KFS quantity may be effected by a portable measuring device at different locations of the carding machine. Assuming the presence of a carding clearance setting system as described in connection with FIGS. 4 a , 4 b and 5 , it is feasible to integrate the KFS quantity determining system into the carding machine. In such a case cleaning of the filter may be effected by reversing the airflow by virtue of reversing the direction of operation of the fan 23 .
It will be understood that the above description of the present invention is susceptible to various modifications, changes and adaptations, and the same are intended to be comprehended within the meaning and range of equivalents of the appended claims. | A carding machine includes clothed rolls for processing and carrying fiber material thereon; an arrangement for separating lightweight waste from the fiber material processed by the clothed rolls; a conduit for receiving the lightweight waste; an air stream generating arrangement for generating an air flow in the conduit for removing the lightweight waste; an adjusting device for varying a degree of carding intensity of the carding machine; and a detecting device for measuring quantities of the lightweight waste produced at a respective degree of carding intensity. | 3 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a device for opening both locks of a double-locked door simultaneously.
2. Description of the Prior Art
There is a need for anti-burglary devices and a door equipped with two or more locks is very popular for this purpose. Indeed, the more locks that are used, the safer houses are considered to be, but a plurality of locks makes it more inconvenient for dwellers to open a door because they have to unlock the locks one by one.
BRIEF SUMMARY OF THE INVENTION
It is an object of the invention to eliminate such inconvenience by providing a device which can unlock two locks simultaneously by only one action of turning the main lock.
This invention makes use of a linking plate which is bored with two straight slots which are respectively provided with a hooking hole at one of their ends so as to link with one end of a spring. The linking plate has a hook at its two sides sandwiched between a surface plate and a bottom plate. The surface and bottom plates are respectively bored with two shaft holes for matching with two shaft collars so as to respectively receive a main lock and an auxiliary lock; and the two shaft collars are each coupled with a main and an auxiliary disc. When the main lock is turned manually the main disc will force the linking plate to move and another hook of the linking plate will simultaneously cause the auxiliary disc to rotate which results in a united opening action for both the locks at the same time.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will now be described in detail with reference to the accompanying drawings, wherein:
FIG. 1 is a top plan view of a linking plate of this invention;
FIG. 2 is a cross-sectional view taken along line II--II of FIG. 1;
FIG. 3 is a to plan view of a bottom plate of this invention;
FIG. 4 is a cross-sectional view taken along line IV--IV of FIG. 3;
FIG. 5 is a top plan view of a surface plate of this invention;
FIG. 6, is a cross-sectional view taken along line VI--VI of FIG. 5;
FIG. 7 is a top plan view of a main disc of this invention;
FIG. 8 is a cross-sectional view taken along line VIII--VIII of FIG. 7;
FIG. 9 is a top plan view of an auxiliary disc of this invention;
FIG. 10 is a cross-sectional view taken along line X--X of FIG. 9;
FIG. 11 is a top plan view of a main shaft collar of this invention;
FIG. 12 is a cross-sectional view taken along line XII--XII of FIG. 11;
FIG. 13 is a top plan view of an auxiliary shaft collar of this invention;
FIG. 14 is a cross-sectional view taken along line XIV--XIV of FIG. 13;
FIG. 15 is a top plan view of this invention assembled with two locks in unlocked position;
FIG. 16 is a top plan view of this invention assembled with two locks in locked position;
FIG. 17 is a top plan view of this invention assembled in operating condition;
FIG. 18 is a side elevational view of a door utilizing the first example of this invention;
FIG. 19 is a vertical cross-sectional view through the lock assembly of FIG. 18;
FIG. 20 is a view similar to FIG. 18 showing the second example of this invention with a lever handle lock; and
FIG. 21 is a view similar to FIG. 18 showing the third example of this invention with a tubular lock.
DETAILED DESCRIPTION
This invention comprises linking plate 1, bottom plate 2, surface plate 3, main disc 4 and auxiliary disc 5 as important parts.
FIGS. 1 and 2 show the structure of linking plate 1, which is formed by pressing and has two straight slots 11, each of which is provided with hooking hole 12 at one of its ends for hooking with one end of a spring 6. Two ends of linking plate 1 are respectively provided with two hooks 13, 14.
FIGS. 3 and 4 show the structure of bottom plate 2, which has two slots 21 aligned with slots 11 of linking plate 1 when assembled, two shaft holes 22, 23 for the shaft of a lock to run through, and two threaded holes 24 for screws 37 to attach the surface plate 3. In addition, at opposite sides of each shaft hole 22, 23 are bored two holes 25 for fixing the bottom plate on a door.
FIGS. 5 and 6 show the structure of surface plate 3. The inside of surface plate 3 has two offset concave discs 31, which are to match, respectively, with main disc 4 and auxiliary disc 5, which are bored with round holes 32, 33 for the shafts of two locks to run through, two hooking holes 34 for spring 6 to hook to, and guarding wall 35 for restricting movement of linking plate 1. Peripheral wall 36 spaces surface plate 3 from the bottom plate to provide operating space between them for linking plate 1 after surface plate 3 is fixed on a door. Surface plate 3 is fixed on bottom plate 2 by screws 37 engaging holes 24 (FIG. 19). Two sets of U-shaped restricting projections 38, 39 are provided at the inside bottom of surface plate 3 to limit linking plate 1 to move in a straight line between them. Two retaining bars 30 engage with the two sets of U-shaped restricting projections 38, 39 by pressing the bars into the projections to retain linking plate 1 on surface plate 3.
Main disc 4, as shown in FIGS. 7 and 8, has hole 41 therein for the shaft of the main lock, described below, and has two protruding rings 42 on its two sides.
Auxiliary disc 5, as shown in detail in FIGS. 9 and 10, is provided with shaft hole 51 for the shaft of an auxiliary lock 7 to run through and with two linking protrusions 52 at its two sides.
FIGS. 11 and 12 show the structure of main shaft collar 43 which is to combine with a lever handle lock, a tubular lock or an antique lock, and activates main disc 4 when rotated. In slot 44 in main shaft collar 43, C-shaped retaining ring 45 (FIG. 19) retains main shaft collar 43 in round hole 33 of surface plate 3.
Next, as shown in FIGS. 13 and 14, auxiliary shaft collar 53 is used for coupling with an auxiliary lock and to activate auxiliary disc 5 when rotated. And ring slot 54 in shaft collar 53 can be used to retain shaft collar 53 in round hole 32 of surface plate 3.
Both shaft collars 43 and 53 make use of their internal shaft holes for combining with the shafts of various kinds of locks, so that when each lock is rotated, the respective shaft collar is rotated simultaneously. Additionally, the external elliptical shape of shaft collars 43, 53 lock into shaft holes 41, 51 of main disc 4 and auxiliary disc 5 so that when shaft collars 43, 53 are rotated, discs 4 and 5 are also activated to rotate at the same time.
FIG. 19 shows a cross-sectional view of the first embodiment of this invention. Linking plate 1 is slidable on the inside surface of plate 3 and retained by bars 30. Main disc 4 is positioned behind linking plate 1 and shaft collar 43 is assembled in round hole 33 of surface plate 3. Shaft collar 43 is combinable with an antique lock 54 as shown in FIG. 18, with a lever handle lock 55 as shown in FIG. 20, or a tubular lock 56 as shown in FIG. 21. Auxiliary disc 5 is assembled on shaft collar 53 which is assembled in round hole 32 of surface plate 3. Shaft collar 53 is combinable with the turning button 7 of an auxiliary lock. The main and auxiliary lock assemblies are installed on the inside of surface plate 3 to become unitary activating devices fixed on the inner surface 60 of a door 61, as shown in FIG. 18.
One common property of an auxiliary lock, a main antique, lever handle, or tubular lock, etc., is that each of the locks must be independently turned around from the inner or the outer side of a door to force its dead bolt to move in or out. The simultaneous opening device of this invention is installed at the inner side of a door, so that opening a door from the outside still requires a normal process, i.e., two independent steps are necessary for opening a door from the outside to preserve the anti-burglary feature.
FIG. 15 shows a top view of this invention in the position where the auxiliary lock is not locked. Two linking protrusions 42 of main disc 4 keep in contact with one hook 13 of linking plate 1, hooking holes 12, 34 are respectively hooked by one end of springs 6, and the two linking protrusions 52 do not contact with either hook 14 of linking plate 1.
FIG. 16 shows all the locks locked from the inside. The locked condition of an antique lock, lever handle lock, or tubular lock, does not affect the position of main disc 4. But the locking method of an auxiliary lock is to rotate turning button 7. Whether turning button 7 is turned clockwise or counterclockwise, auxiliary disc 5 and shaft collar 53 are turned with it and one of the linking protrusions 52 comes in contact with and moves one hook 14 of linking plate 1.
Supposing that the unitary opening device of this invention is not equipped on a door, and that it is necessary to open the door from the inside as shown in FIGS. 18, 20, 21 when both locks are in the locked position, then it is necessary to turn turning button 7 to its unlocking state and then rotate the main lock to the unlocked position for the purpose of opening the door. But, if the door is equipped with this invention, as shown in FIG. 16, it is not necessary to rotate turning button 7 first, but only to turn the main lock directly so that linking protrusions 42 of main disc 4 move hook 13 thereby moving linking plate 1 (FIG. 17) whereby hook 14 at the other end of linking plate 1 pushes linking protrusions 52 of auxiliary disc 5 which rotates until the auxiliary lock is totally opened as shown in FIG. 17, thus allowing opening the door. That is, the rotation of turning button 7 and the main lock pull their dead bolts inside out of the door frame. When the force for rotating the main lock ceases, the main lock will recover its normal state as in the known art of a conventional door lock, and linking plate 1 will also recover its normal position through the action of return springs 6 to the retracted position where it is stopped by guarding wall 35.
In conclusion, this invention provides a convenient device that saves time in opening a door with two locks from inside without sacrificing any anti-burglary effect. | An opening device for simultaneously opening two locks of a double-locked door fixed only at the inside of the door for simplifying the action of opening from the inside comprises a cam-operated sliding plate displaceable by a cam actuator on the shaft of the main lock-rotating handle which when displaced simultaneously rotates the shaft of the auxiliary lock by camming action to the unlocked position, but when opening the door from the outside the device does not unlock both locks simultaneously and the opening process requires two separate operations for preserving the anti-burglary features of a normal double-lock system. | 4 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority to U.S. Provisional Application No. 61/192,432 entitled “Drivehead Assembly For A Rope Pump System,” filed on Sep. 18, 2008.
FIELD OF THE INVENTION
[0002] The present invention relates to an improved method and apparatus for moving fluid. In particular, the invention relates to a synchronized drive head assembly containing a set of counter rotating sheaves with an endless conveyor and used to move fluids.
BACKGROUND OF THE INVENTION
[0003] Using a continuous rope or belt as a conveyor looped between a sheave at a particular destination and a sheave at a particular origin to move fluid is known in the prior art. Often the fluid conveyor is used to lift water or oil from beneath the surface of the ground to a storage receptacle on the surface. In this specific use of lifting fluid up to the surface, a well bore of sufficient length to reach the fluid is drilled and a fluid entraining conveyor or belt is secured around a sheave submerged in the fluid. A sheave system rigged on the surface is designed to minimize the effort required to lift the fluid entraining conveyor to the surface. The system must have sufficient traction between the sheaves and the conveyor to lift the combined weight of the conveyor and the fluid. Typical fluid conveyors of the prior art use a mechanical device to turn one sheave which pulls a rope up out of a well and returns the rope back into the well as it unwinds off the sheave. The fluid in the well follows the rope up and is subsequently collected in a containment vessel on the surface.
[0004] The efficiency of a fluid conveyor is determined by the amount of product collected as compared to the amount of energy used to run the device. Efficiency is lost when the conveyor slips on the drive sheave due to low traction between the conveyor and the sheave. Slippage causes wear on the conveyor and therefore reduces its useful life. To generate sufficient traction to prevent slippage, tension in the rope is typically high. The tension in the conveyor being a combination of factors such as, the type of fluid being lifted, the speed of the conveyor, the diameter of the conveyor, and the friction of the conveyor against the sheaves. A common problem with the fluid conveyors of the prior art is the failure of the conveyor due to slippage or high tension. The typical lifespan of the conveyor used in the prior art is approximately ninety (90) days. The relatively short lifespan of the conveyor increases the cost of the system which is a distinct disadvantage of the prior art.
[0005] Typical of the prior art is U.S. Pat. No. 4,652,372 to Threadgill. Threadgill discloses a liquid separator utilizing an endless belt for skimming extraction of oil from a liquid body and doctoring rollers for gathering the oil from both sides of the belt. The endless belt is fabricated from a material which is preferentially wettable by the liquid to be extracted. One drive roller winds the belt up out of the well and around a pair of doctoring rollers. Both sides of the belt engage a doctoring roller to skim the liquid off the belt. An additional roller positioned in the liquid maintains tension in the belt. The tension in the belt and the skimming process needed to remove the liquid from both sides of the belt tend to shorten the lifespan of the belt.
[0006] U.S. Pat. No. 6,158,515 to Greer, et al. discloses an artificial lifting device for well fluids using a continuous loop of fibrous material, such as a rope. The rope loop is formed around a drive sheave on the surface with a return sheave down inside of the well. The drive sheave has ridges along the side surfaces of a groove. The rope lays in the groove in contact with the ridges. A motor rotates the drive sheave, as guides and wipers direct the rope into the drive sheave and to the wipers. The wipers are slotted cards that scrape a quantity of fluid from the outside surface of the rope. The useful life of the rope is diminished by the contact with the ridges in the groove and the scraping of the wipers.
[0007] U.S. Pat. No. 5,080,781 to Evins, IV discloses a down-hole hydrocarbon collector that incorporates an endless absorption belt for collecting low-viscosity hydrocarbon liquids from a well and pumping those liquids to the surface. The collector of the invention has a means for driving the belt through a body of liquid to absorb low-viscosity hydrocarbons, which includes rollers engaging the endless belt in a manner that squeezes the hydrocarbons from the belt. The use of springs enables the squeezing of the belt between rollers. The squeezing of the belt exposes the belt to additional abrasion and hence limits its lifespan.
[0008] U.S. Pat. No. 5,423,415 to Williams discloses a rope pump for conveying fluid-like material from a reservoir to a select location. The surface assembly for the rope pump includes an endless rope, sheaves for forming the endless rope into a loop extending between the reservoir and the select location and a drive for driving the rope about the sheaves. The drive includes a first and second sheave each having a plurality of circumferential grooves. The endless rope is wrapped between the first and second sheaves in the grooves in a block and tackle fashion. A tensioning wheel biases the rope to maintain the rope in constant engagement with the final grooves of the first and second sheave. The tensioning wheel provides constant tension on the rope on the drive sheaves to continuously eliminate rope slack. The constant tension in the rope, especially on the downward side of the loop puts undue strain on the rope and reduces its lifespan.
SUMMARY OF INVENTION
[0009] The preferred embodiment of the present invention provides an efficient and dependable device for driving a conveyor through the length of a well bore to collect fluids. The present invention incorporates two synchronized sheaves. A “figure-8” conveyor path between the synchronized sheaves maximizes the contact of the conveyor with the sheaves and not only improves traction between the sheaves and the conveyor but also allows for zero tension on the conveyor as it reenters the tubing in the well bore. The sheaves include coaxial grooves, each having a unique and novel cross-section that further improves traction without unnecessary abrasion on the conveyor. Under normal working load conditions, as measured by conveyor tension, the invention significantly increases conveyor lifespan.
[0010] Accordingly, an embodiment of the present invention provides a drive head assembly for a fluid conveyor which includes a double sided drive mechanism, such as gears or a double sided drive belt, engaged with a drive wheel and three follower wheels. A first follower wheel shares a rotational axis with a first sheave. A second follower wheel shares a rotational axis with a second sheave. The drive mechanism engages the first and second follower wheels in such a way as to impart a synchronous but opposite rotation to them. The first and second sheaves are connected to the first and second follower wheels respectively via shared rotational axes. The first and second follower wheels impart a synchronous but opposite rotation to the first and second sheaves. The first and second sheave each has a set of coaxial grooves. The preferred embodiment has four coaxial grooves on each sheave. Each groove on the first sheave matched to a groove on the second sheave to form a set of grooves. An endless conveyor follows a “figure-8” conveyor path, through each groove between the sheaves. The “figure-8” conveyor path maximizes the contact surface between the sheaves and the conveyor providing improved traction on the conveyor. The cross-sectional area of the conveyor expands as tension in the conveyor is reduced following each loop around the pair of sheaves. Similarly, the width of each consecutive groove increases to accommodate the conveyor. The depth of each groove, between the lowest portion of each groove and the center of the sheave, is also related to the cross-sectional area of the conveyor. The first groove of each sheave is slightly shallower than that of the adjacent groove which is slightly shallower than the next adjacent groove and so forth. As a result of the progressive increase in depth of each groove, the distance between the cross-sectional center of the conveyor and the rotational axis is slightly reduced in each consecutive groove of the sheave. The conveyor travels down a two-channeled tubing to a remote sheave and returns up the tubing to the sheaves entraining fluid from a reservoir. The drive head assembly of the present invention is surrounded by a sealed cover. The cover, which acts as a containment vessel, protects the environment from the fluids lifted. Additionally, the cover allows a pressurized interior, if necessary, and collects the fluid entrained on the returning conveyor. An outlet port in the cover directs the collected fluid to a holding tank.
[0011] A single pair of sheaves is described for simplicity. However, the drive head may contain more than two sheaves.
[0012] Those skilled in the art will further appreciate the above-mentioned features and advantages of the invention together with other important aspects upon reading the detailed description that follows in conjunction with the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] In the detailed description of the preferred embodiments presented below, reference is made to the accompanying drawings.
[0014] FIG. 1 is an elevation view of the drive head of a preferred embodiment with the cover removed.
[0015] FIG. 2 is an elevation view of the drive head of a preferred embodiment showing the conveyor path.
[0016] FIG. 3 is a partial elevation view of the sheaves of a preferred embodiment showing the conveyor path.
[0017] FIG. 4 is a partial elevation view of a sheave of a preferred embodiment showing the cross-section areas of the conveyor.
[0018] FIG. 5 is a close up elevation view of a groove of a preferred embodiment.
[0019] FIG. 6 is an isometric view of the drive head of a preferred embodiment.
[0020] FIG. 7 is a cross-section view of a well bore in operation with the drive head of a preferred embodiment.
[0021] FIG. 8 is an isometric view of an alternate embodiment.
[0022] FIG. 9 is a cutaway view of sheaves of FIG. 3 , showing the variables necessary to formulate the equations for the radii of each groove in a given sheave.
[0023] FIG. 10 is a cutaway view of a sheave, showing the deformation of the conveyor inside a sheave.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0024] In the descriptions that follow, like parts are marked throughout the specification and drawings with the same numerals, respectively. The drawing figures are not necessarily drawn to scale and certain figures may be shown in exaggerated or generalized form in the interest of clarity and conciseness.
[0025] FIGS. 1 , 2 and 6 show a preferred embodiment of drive head 100 . Base 102 provides a connecting platform for motor 116 , transmission 118 , and frames 104 and 106 . In the preferred embodiment, base 102 is mounted to ground surface 108 via a concrete slab. Brace 220 stabilizes frame 104 to frame 106 . Frames 104 and 106 are parallel to each other and extend from base 102 at angle A. Angle A may be any angle, including perpendicular. In the preferred embodiment, angle A ranges from 80° to 85°.
[0026] In the preferred embodiment, motor 116 generates up to 10 horsepower and is powered by fuel or electricity. However, motor 116 may be of any size or type. The size of motor 116 may be altered to account for the weight of the conveyor 142 , density of the fluid, speed of operation, the size of the sheaves 110 and 112 , and the size of follower wheels 124 , 126 , and 128 . Motor 116 is removably secured to base 102 and is additionally connected to transmission 118 to provide rotational motion to drive shaft 122 . Drive shaft 122 extends from transmission 118 . Drive wheel 120 is notched along its perimeter and is concentrically mounted on drive shaft 122 . Drive shaft 122 provides a rotational axis for drive wheel 120 .
[0027] Follower wheels 124 , 126 , and 128 are concentrically mounted on one end of shafts 134 , 136 , and 138 respectively. In the preferred embodiment, follower wheels 124 , 126 , and 128 are all generally equal in shape and size and their midpoints are linearly aligned on the longitudinal midline 140 of frame 104 . In the preferred embodiment, the diameter of follower wheels ranges from 8 to 10 inches. However, the follower wheels 124 , 126 , and 128 may be of any size. Additionally, geometry could be selected such that follower wheels 124 , 126 , and 128 were not the same size as each other. The size of the follower wheels 124 , 126 , and 128 are generally selected based on the weight of the conveyor 142 , the diameter of sheaves 110 and 112 , density of the fluid and power of the motor 116 . Additionally, in a different prepared embodiment follower wheels 124 and 134 are not used.
[0028] Shafts 134 , 136 , and 138 are mounted in and perpendicularly extend between frames 104 and 106 . Rotating shaft support 230 mounted in frame 104 and rotating shaft support 232 mounted in frame 106 provide for rotation of shaft 138 . Rotating shaft support 234 mounted in frame 104 and rotating shaft support 236 mounted in frame 106 for rotation of shaft 136 . Rotating shaft support 238 mounted in frame 104 and rotating shaft support 240 mounted in frame 106 for rotation of shaft 134 . Additionally, in a different preferred embodiment, Follower wheels 124 and 134 are not used.
[0029] In a preferred embodiment, the perimeter of follower wheels 124 , 126 , and 128 have equally spaced cogs for engagement with double-sided toothed belt 114 . Belt 114 has teeth on opposite surfaces for engagement with the notches of drive wheel 120 and the cogs of the follower wheels. Belt 114 is propelled by drive wheel 120 .
[0030] As shown in FIG. 1 , belt 114 winds from drive wheel 120 , around follower wheel 124 , crosses midline 140 , around follower wheel 126 , crosses midline 140 again, around follower wheel 128 , and back down to drive wheel 120 . The arrows shown on drive wheel 120 and the follower wheels indicate the rotational direction of the follower wheels with respect to the drive wheel. Belt 114 is wound as such to ensure that follower wheels 126 and 128 rotate in opposite directions. Although follower wheels 126 and 128 rotate in opposite directions, belt 114 synchronizes them to rotate at the same speed.
[0031] Sheave 110 is generally cylindrical in shape and is rigidly mounted to shaft 138 . Shaft 138 is a rotational axis for sheave 110 . Sheave 112 is generally cylindrical in shape and is rigidly mounted to shaft 136 . Shaft 136 is a rotational axis for sheave 112 . Follower wheel 128 , shaft 138 , and sheave 110 all rotate in unison and in an opposite direction of follower wheel 126 , shaft 136 , and sheave 112 which also rotate in unison. Because follower wheel 126 and 128 are synchronized to rotate at the same speed in opposite directions, it follows that sheaves 110 and 112 are also synchronized and rotate at the same speed in opposite directions. In the preferred embodiment, sheave 110 and follower wheel 128 rotate at the same RPM as sheave 112 and follower wheel 126 .
[0032] As shown in FIGS. 2 , 4 , and 6 , sheave 110 in a preferred embodiment of the present invention is made up of four integrally formed coaxial grooves 202 , 204 , 206 , and 208 . In alternate embodiments, the total number of grooves on each sheave varies depending on the depth of the well bore and the traction required. The total number of grooves on each sheave is determined by the amount of tractive force required to propel the conveyor. The curvature of the groove walls has a cross sectional profile determined by a function described in FIG. 9 . The grooves are adjacent each other and increase in width as the diameter of the conveyor 142 increases. Thus, the cross sectional profile of groove 202 (and conveyer segment 402 ) is the most narrow and groove 208 (and conveyor segment 408 ) is the widest. Generally, the ratio of the profile of groove 202 to the profile of groove 204 and the ratio of the profile of groove 204 to the profile of groove 206 and so forth should be in the range of 1.01 to 1.1. The width of the groove profile depends on the elasticity of the conveyor (which is assumed to be constant) and the amount of tensile force applied to it. The tensile force applied to the conveyor is a function of the diameter of the conveyor, the speed at which the conveyor is being propelled, the viscosity of the fluids being moved, and overall weight of the conveyor. The functions are more fully explained with the descriptions of FIGS. 9 and 10 that follow.
[0033] In the preferred embodiment, sheave 112 is generally the same size as sheave 110 . Sheave 112 is also made up of four integrally formed coaxial grooves 212 , 214 , 216 , and 218 . The grooves are adjacent each other and linearly step down in radius where groove 212 has the largest radius and groove 218 the smallest, as described for sheave 110 above.
[0034] FIG. 4 shows a partial view of sheave 110 . It is understood that sheave 112 is structurally similar. The step down in radius of the grooves is necessary to counteract the expanding diameter of conveyor 142 . Accordingly, radius 422 of groove 202 is greater than radius 424 of groove 204 . Radius 424 of groove 204 is greater than radius 426 of groove 206 . Radius 426 of groove 206 is greater than radius 428 of groove 208 . As conveyor 142 loops around the grooves of the sheaves (the preferred path to be described below), tension is lessened and the cross-sectional area of conveyor 142 increases. In the preferred embodiment, distance 422 ranges from approximately 5.5 to 6 inches to as small as 2 inches. However, distance 422 may be of any size. Distance 422 may be selected based on the diameter of follower wheels 124 , 126 , and 128 , weight of conveyor 142 , density of fluid 630 and size of motor 116 . Because of the elasticity of the conveyor, as tension in a segment of conveyor 142 is reduced the length of the segment is also reduced. Therefore the shorter radius of each sequential groove is necessary to keep slack out of the windings and prevent slippage. Slippage produces unwanted wear on the conveyor.
[0035] FIG. 5 shows the shape of the conveyor receiving grooves. The cross-section of each groove has two sides, each side having a different profile and slope, as described by equations 11 and 13, due to point 508 not being located along centerline 522 of groove 202 . For clarity, only grooves 202 and 204 are shown. It is understood that all additional grooves will be similarly shaped. The unique shape of the grooves eliminates the need for tension on down portion 304 of conveyor 142 and grips the conveyor without cinching the conveyor thereby prolonging conveyor life. Groove 202 includes profile 502 and groove 204 includes profile 504 . Profile 502 is formed by the two curves 506 and 510 which are defined by a specific equation. The equation is a function of the groove radius and the pitch between alternate grooves on different sheaves. As previously mentioned and shown later with the descriptions of FIGS. 9 and 10 , the groove radius depends on the elasticity of the conveyor and the amount of tensile force applied to the conveyor. The tensile force applied to the conveyor is a function of the diameter of the conveyor, the speed at which the conveyor is being propelled, the viscosity of the fluids being moved, and the overall weight of the conveyor. Curve 506 and 510 intersect at point 508 . Intersection point 508 is located off centerline 522 . Because the intersection point of curves 506 and 510 is off centerline 522 , curve 510 has a more gradual slope than curve 506 and the conveyor naturally rests in profile 502 off-center as well. Curve 506 provides a less obstructive angle of departure as conveyor 142 proceeds from one groove on a sheave to another groove on a different sheave. Profile 504 is formed by the two curves 512 and 516 which intersect at point 514 and are defined by a different equation. The equation is not the same as the equation for curves 506 and 510 defining profile 502 because the equations are a function of groove radius and the radius of groove 204 is less than that of groove 202 .
[0036] As best shown in FIG. 3 , sheave 110 is located distance 310 from sheave 112 . As conveyor 142 passes from sheave 110 , crosses midline 140 and loops back around on sheave 112 , conveyor 142 generally makes contact with a majority of the perimeter of each sheave. As the conveyor first enters sheave 110 from the well bore and finally exits sheave 112 to enter the well bore, the contact with sheaves 110 and 112 is reduced as the conveyor 142 enters and leaves vertically. This is further described in equation 1. Conveyor 142 continues this “figure-8” conveyor path, alternating between the sheaves for as many grooves as there are in each sheave. As distance 310 decreases, the more contact conveyor 142 makes with each sheave and thus more tractive force. The optimal distance between the sheaves maximizes the contact conveyor 142 has with the perimeters of each sheave while still allowing enough space for conveyor 142 to cross grooves without obstruction. Conveyor 142 contacts both sheaves through angle B. In the preferred embodiment, angle B ranges from 320° to 340° except for the first and last groove as described above. The more surface contact conveyor 142 has with the sheaves, the more tractive force will be produced.
[0037] Referring to FIG. 6 , cover 602 is generally rectangular and hollow. Cover 602 encases frames 104 and 106 and sheaves 110 and 112 . Follower wheels 124 , 126 , and 128 are adjacent cover 602 and located on the exterior of cover 602 . Cover 602 further defines entrance hole 610 and exit hole 612 . Drain hole 606 allows the fluid moved from the reservoir to be removed from collection area 618 and transported to an additional storage receptacle. Standpipe 604 is fitted to the underside of cover 602 below collection area 618 . Standpipe 604 extends from the upper portion of the well bore.
[0038] The preferred path of conveyor 142 can be seen in FIGS. 2 , 3 , and 6 . Up portion 302 of conveyor 142 enters drive head 100 through entrance hole 610 in cover 602 . It is not necessary for conveyor 142 to be perpendicular to base 102 while it is in the enclosed area of cover 602 . Up portion 302 must have an unobstructed path from entrance hole 610 to groove 202 and down portion 304 must have an equally unobstructed path from groove 218 to exit hole 612 . After entering cover 602 , conveyor 142 passes over and around sheave 110 in groove 202 . Conveyor 142 leaves groove 202 , crosses midline 140 between the sheaves and rounds sheave 112 in groove 212 in an opposite rotational direction than around sheave 110 . Arrows 306 and 308 indicate the rotational directions of each sheave are opposite each other. Conveyor 142 then leaves groove 212 , crosses midline 140 and rounds sheave 110 in groove 204 . This “figure-8” conveyor path continues for the remaining grooves until conveyor 142 leaves groove 218 and down portion 304 exits covers 602 through exit hole 612 .
[0039] Referring to FIGS. 6 and 7 , once conveyor 142 passes through exit hole 612 it travels through down chamber 616 of flexible tubing 608 . Flexible tubing 608 has two separate passageways that extend throughout the length of flexible tubing 608 , down chamber 616 and up chamber 614 . Drop housing 620 is affixed to the end of flexible tubing 608 that is furthest from drive head 100 . Drop housing 620 is lowered to a sufficient depth in well bore 704 in order to come into contact with fluid 630 . Conveyor 142 enters drop housing 620 and travels around distal sheave 624 . Distal sheave 624 is secured to a cone shaped section of drop housing 620 shown as nose 622 . Drop housing 620 further includes a plurality of inlets 626 . Inlets 626 are openings in drop housing 620 which allow fluid 630 to enter into the interior of drop housing 620 and become adjacent to conveyor 142 . After looping around distal sheave 624 , the conveyor returns through up chamber 614 and begins the path again starting in groove 202 of sheave 110 .
[0040] In operation, drive head assembly 100 is mounted to standpipe 604 extending from well bore 704 . Up portion 302 of conveyor 142 is looped between sheave 110 and sheave 112 in a “figure-8” conveyor path. Down portion 304 is looped around distal sheave 624 secured to drop housing 620 . Drop housing 620 is lowered into well bore 704 until it reaches the fluid to be pumped. A power delivery system turns drive shaft 122 which in turn rotates drive wheel 120 . Belt 114 is strung around drive wheel 120 and follower wheels 124 , 126 , and 128 . Belt 114 causes follower wheels 124 and 128 to rotate in the same direction as drive wheel 120 and follower wheel 126 to rotate in the opposite direction of drive wheel 120 . Belt 114 synchronizes follower wheels 126 and 128 to rotate at the same speed. Follower wheel 128 causes sheave 110 to rotate and follower wheel 126 causes sheave 112 to rotate. As a result, belt 114 synchronizes sheaves 110 and 112 to rotate at the same speed. In the preferred embodiment, follower wheels rotate in the range of approximately 250 RPM to 600 RPM resulting in a conveyor speed ranging between approximately 700 feet per minute (fpm) and 1,700 fpm. However, other speeds are envisioned based on the diameter of the follower wheels, the diameter of the sheave and the overall weight of the conveyor.
[0041] In alternate embodiments, follower wheels 124 , 126 and 128 may be smooth and driven by a smooth belt. Alternately, they may consist of meshed gears. Finally, they may be sprockets utilizing a chain drive from the drive wheel 120 .
[0042] Sheaves 110 and 112 pull conveyor 142 up through up chamber 614 of flexible tubing 608 , up through entrance hole 610 , and around each other. Sheave 112 guides conveyor 142 down through exit hole 612 and through down chamber 616 . Down portion 304 of conveyor 142 moves as a result of the force applied by sheaves 110 and 112 to up portion 302 . As conveyor 142 travels through the length of well bore 704 , conveyor 142 uses the principals of Couette flow theory to entrain a quantity of fluid 630 . In fluid dynamics, Couette flow refers to the laminar flow of a viscous liquid in the space between two surfaces, one of which is moving relative to the other. The flow is driven by virtue of viscous drag force acting on the fluid and the applied pressure gradient between the surfaces. Here, the two surfaces are conveyor 142 moving relative to flexible tubing 608 . Fluid 630 travels with conveyor 142 up flexible tubing 608 and acts to support, displace, or offset the conveyor from the sides of the tubing. For a more detailed description of a fluid entraining conveyor and flexible tubing advantageously used with the invention, reference is made to U.S. Pat. No. RE 35,266 to Crofton, et al., this is fully incorporated by reference herein.
[0043] Fluid 630 enters cover 602 through entrance hole 610 and pools in collection area 618 . Fluid 630 is pumped or otherwise transported from collection area 618 through drain hole 606 to a storage receptacle until processed or transported further.
[0044] FIG. 8 shows an alternate embodiment of the present invention. Drive head 800 , including hydraulic motor 820 and follower wheels 826 and 828 are all encased in sealed cover 823 . Cover 823 (shown in cutaway) is generally cylindrical in shape and encloses the working components of drive head 800 . Cover 823 is mounted to lip 802 via a plurality of bolts through attachment holes 806 . Seal 824 resides in annular grooves 826 and 827 . Seal 824 , in cooperation with annular grooves 826 and 827 , seals the working components of drive head 800 with respect to the outside pressure. Lip 802 is integrally formed with the open end of standpipe 804 . Standpipe 804 extends from the upper portion of the well bore. Base 814 is mounted to standpipe 804 . Base 814 is a disc shape having rectangular opening 818 . Rectangular opening 818 provides access for the conveyor (not shown) down into the well bore. Frame 808 is supported on base 814 by buttresses 824 and 826 . In the preferred embodiment, frame 808 extends from base 814 at an angle that ranges from 80° to 85°. However other angles including perpendicular to the base are envisioned.
[0045] Frame 808 is generally a rectangular shape and provides mounting points for sheaves 810 and 812 and also follower wheels 826 and 828 . Frame 808 includes frame extension 816 . Frame extension 816 provides a mounting point for hydraulic motor 820 . Hydraulic motor includes valves 822 for input and output of the hydraulic fluid that powers hydraulic motor 820 . Sheaves 810 and 812 are mounted on axles which axially rotate in frame 808 . Follower wheels 828 and 826 are linearly aligned and mounted on the same axles extending through frame 808 .
[0046] In the preferred embodiment, follower wheels 828 and 826 have equally spaced cogs for engagement with a double-sided toothed belt. A double-sided toothed belt driven by a drive wheel connected to hydraulic motor 820 rotates follower wheels 826 and 828 . Follower wheels 826 and 828 are synchronized to rotate at the same velocity and in opposite directions. By virtue of follower wheels 826 and 828 being mounted on the same rotational axes as sheaves 812 and 810 respectively, sheaves 810 and 812 also rotate at the same speed and in opposite directions.
[0047] In alternate embodiments, follower wheels 826 and 828 may be smooth and driven by a smooth belt. Alternately, they may consist of meshed gears. Finally, they may be sprockets utilizing a chain drive from the drive wheel.
[0048] Sheaves 810 and 812 are each shown with two coaxial grooves. The total number of coaxial grooves on each sheave can vary depending on the depth of the well bore and the traction required to propel the conveyor. The grooves have a cross-sectional shape of a V with concave sides as previously described. The conveyor is wrapped around the sheaves and down into the well bore via a double chambered flexible tubing in the same manner as described in previous embodiments.
[0049] The embodiment in FIG. 8 is used in situations where the fluid to be moved is under pressure. The outer casing includes the cover and standpipe 804 , as well as seals and gaskets between them to maintain the pressure. In the preferred embodiment, container vessel can maintain pressure up to several thousand psi. However, greater pressures may be achieved as such casings, seals and fittings are well known in the art.
[0050] The present invention is useful for any fluid production system by which fluid is to be transported a long distance using a conveyor. Additionally, the drive head assembly of the present invention incorporating the synchronized sheaves, the “figure-8” conveyor path between the sheaves, and the uniquely shaped grooves of the sheaves can be used in any conveyor configuration wherein high tractive forces are required of the conveyor and prolonged conveyor life is desired.
[0051] Referring now to FIGS. 9 and 10 determination of the radii and shape of those grooves will be described assuming an elastic conveyor, driven under tension by friction between the groove walls and the conveyor.
[0052] The size of gap, w 1 , between the sheaves and the grooves controls the departure and entry points for the conveyor in each of the respective sheave grooves. The entry and departure points are the points on the centerline of contact between the groove walls and the conveyor arrives at or leaves from its resting point in the groove. A line is drawn in FIG. 9 between the center point of the first sheave 110 and the departure point of the conveyor and annotated at “r 1 ”. A similar line from the center point of the second sheave 112 to the conveyor entry point in its first groove is shown as “r 2 ”. A midline 140 is shown between the center points of the two sheaves, which are a distance “D” apart. Notice that the midline 140 is canted from vertical by an angle of δ.
[0053] Referring to FIG. 10 , the centerline of contact with the conveyor is shown. That centerline is also the location of a point load on the walls and conveyor, which is equivalent to the distributed load over the contact area. FIG. 10 also portrays the cross-section of the sheave grooves and an approximate shape of the loaded conveyor, when in the groove. A V-shaped sheave groove is utilized for ease of calculating angle γ. As previously described, the walls of the groove may be concave to allow for deformation of the conveyor and the pitch between grooves on alternate sheaves. The position of the entry and departure points depends on the conveyor velocity, mechanical properties of the conveyor and geometry of the groove.
[0054] The angle between the line denoted as “r 1 ” and the line between the sheave center points is referred to as “β 1 ”. The angle between “r 2 ” and the midline 140 on the second sheave is identified as “β 2 ”. Assuming that the conveyor entry and departure points are tangent to the circular centerline of contact, then fundamental principles of analytic geometry require that the angles “β 2 ” and “β 1 ” are equal. By the same geometric principles that triangles with similar angles must have proportional sides, then:
[0000]
r
1
r
2
=
h
1
h
2
=
r
1
+
fw
1
r
2
+
w
1
(
1
-
f
)
eq
.
(
1
[0000] where “h 1 ” represents the distance from the center point of the first sheave 110 and the point where the conveyor crosses the line between the center points and “h2” that relative to the center point of the second sheave. The variable “w 1 ” represents the distance between the grooves of sheave 110 and sheave 112 . The distance between the sheave grooves is measured at the centerline of contact with the conveyor, as depicted in FIG. 10 .
[0055] The value of “f” is related to “w 1 ” such that the product, “f×w 1 ”, is that fraction of the gap from the center of contact on the first sheave 110 to the crossing point of the conveyor. Solving Eqn. 1 for “f” yields:
[0000]
f
=
r
1
r
1
+
r
2
eq
.
(
2
so
,
h
1
=
r
1
(
1
+
w
1
r
1
+
r
2
)
and
eq
.
(
3
h
2
=
r
2
(
1
+
w
1
r
1
+
r
2
)
eq
.
(
4
[0000] By those definitions, then:
[0000]
β
1
=
cos
-
1
(
r
1
h
1
)
=
cos
-
1
(
1
+
r
1
+
r
2
r
1
+
r
2
+
w
1
)
eq
.
(
5
[0056] So for the first groove on the first sheave 110 , the conveyor 302 enters the first sheave 110 at 90 degrees yielding a total conveyor contact angle of
[0000]
θ
1
=
(
3
2
-
δ
-
β
1
)
π
eq
.
(
6
[0000] Notice that the total contact angle is a function of the radius of the groove on the second sheave 112 , because “β 1 ” depends on the value of “r 2 ”. By similar logic, the total contact angle for the second groove, where the conveyor is more fully in contact with the sheave than the first groove, is:
[0000] θ 2 =(2−β 1 −β 2 )π eq. (7
[0057] The same relationships applies to all of the other grooves, except for the first and last grooves where the conveyor enters or departs from the sheaves, so
[0000] θ i =(2−β i−1 −β 1 )π eq. (8
[0058] The relationship for the last groove is similar to that of the first groove:
[0000]
θ
n
=
(
1
2
-
δ
-
β
n
-
1
)
π
eq
.
(
9
[0000] Where “n” is even and the number of the last groove in the train. The total contact angle still depends on the radii of both the last and preceding sheave grooves.
The combined total contact angle of all the grooves is:
[0000] θ total =( n− 1−2(δ+Σ i=1 i=n-1 β i ))π eq. (10
[0000] So, clearly, the solution for each of the groove total contact angles is iterative, since it depends on the radius of both the groove in question and the following groove. The iterative solution converges to a suitable tolerance in two to five iterations.
[0059] If the conveyor were inelastic, the design of the conveyor drive mechanism would simply depend on the coefficient of friction between the conveyor and the sheave groove walls and the combined total contact angle. In fact, the conveyor is quite elastic and for this analysis assumed to exhibit proportional Hookean behavior. That is, the stretch of the bulk conveyor is proportional to the load placed on it. Elastic materials also exhibit a change of shape when loaded. Thus, elastic materials have a functional relationship between the change in length as loading occurs and change in diameter, in this case. The relationship is the Poisson's Ratio. The groove train radii and cross-sections must be corrected for these phenomena.
[0060] The change in size of the conveyor depends on these mechanical properties and the change in tension as the conveyor passes through each groove in the train. In order to determine tractive effort exerted by one groove, assuming the parabolic profile shown in FIG. 10 , it is necessary to first determine the slope of the side of the grooves where the conveyor contacts the groove wall. The equation describing the parabolic profile is:
[0000] x 2 =4 p ( y−k ) eq. (11
[0000] Differentiating this equation with respect to “x” gives the slope of the side:
[0000]
y
x
=
2
x
4
p
eq
.
(
12
[0000] Thus the angle of the side is:
[0000]
γ
=
π
2
-
tan
-
1
(
y
x
)
.
eq
.
(
13
[0000] It appears that the angle is dependent on the distance between the sides of the groove (2x). That distance is dependent on the loaded tension, hence diameter, of the conveyor.
[0061] If in the unloaded condition, the conveyor has a characteristic length “L 0 ” and diameter “d r0 ”, then when fully loaded for entry into the first groove on the first sheave 110 , its length will be:
[0000]
L
1
=
L
0
+
Δ
L
=
L
0
(
1
+
E
T
1
A
1
)
eq
.
(
14
[0000] where “T 1 ” is the maximum tension load (force) on the conveyor,
“ΔL” represents the change in length “E” is the elasticity of the material and “A 1 ” is the cross-sectional area of the loaded conveyor.
The loaded diameter is:
[0000] d r1 =d r0 (1−Δ d r )= d r0 (1−μΔ L ) eq. (15
[0000] where “μ” is Poisson's Ratio for the bulk conveyor.
The loaded area is then:
[0000]
A
1
-
π
d
r
1
2
4
eq
.
(
16
[0000] This computation is also iterative, since the amount of stretch depends on the degree of shrinkage of cross-sectional area. The computation begins by assuming the cross-sectional area of the unloaded conveyor, then correcting the computations as the corrected area in Eqn. 16 is recalculated. The iteration between Eqns. 14-16 is finished when sufficient accuracy is achieved, typically in two to five iterations depending on the elasticity and deformability of the materials.
[0065] Based on the diameter determined in Eqn. 15, the aperture of the parabola at the contact centerline is now known. From that dimension, given the desired depth of the groove, typically, but not necessarily, two conveyor diameters, the value of “p” in Eqn. 11 can be determined. Taking the contact centerline to have a relative value of “y” equal to zero, then the value of “p” is:
[0000]
p
=
d
r
1
40
eq
.
(
17
[0000] and since “x” in Eqn. 12 is also equal to “d r1 ”, then the slope is not a function of the conveyor properties or diameter. Thus, the angle of the slope is only a function of the chosen depth of the groove.
[0066] Since the radius of the first groove would be specified and the width and geometry of the groove are now known, it is possible to determine the amount of tension exerted in the traverse of the groove by the conveyor. The theoretical solution is shown below:
[0000]
T
2
=
T
1
exp
(
-
σ
θ
1
sin
δ
)
eq
.
(
18
[0000] Recall that “θ 1 ” depends on the size of the groove in the second sheave 112 . The conveyor is now shorter and fatter, because of the reduced tension on it as it leaves the first groove. To minimize wear, it is necessary to require that the conveyor not slip in any of the grooves. Therefore, since it is difficult to change their rotational speed, it is best to select a radius that accommodates the reduced length and increased diameter. The second groove will thus have a slightly smaller radius than the first to compensate for the increased diameter and resulting upward movement of the center of contact of the conveyor. The characteristic length under the new loading conditions is:
[0000]
L
2
=
L
0
(
1
+
E
T
2
A
2
)
eq
.
(
19
[0000] where the area and diameter are iterated just as with Eqns. 14-16. So the radius of the second groove (first groove on the second sheave 112 ) will be:
[0000]
r
2
=
r
1
L
2
L
1
eq
.
(
20
[0067] The estimate of “r 2 ” based on the conveyor properties now permits a recalculation of “β 1 ” and “θ 1 ”. This external iteration then proceeds until a suitable tolerance for “r 2 ” has been achieved, typically two to five iterations. Notice, also, that the gap, “w 1 ”, is also a function of the values of “r 1 ” and “r 2 ”. The original value was based on the assumption that the radii were equal, however, now:
[0000] w i =D− ( r i +r i+1 ) eq. (21
[0000] for the i th gap, where D is the distance between the sheave center points.
[0068] The identical calculation is performed for each subsequent groove/sheave pair, including the last one. The only fundamental difference is the use of the appropriate total contacted angle relationship for each groove (Eqns. 6-10). As previously noted, the computations are iterative, but quickly converge.
[0069] A critical test exists for the sizing of the sheaves 110 and 112 . The radius of the sheaves must be large enough that the radial force pulling the conveyor into the groove is substantially larger than the centrifugal force attempting to fling the conveyor out of the groove. For the sake of computation, assume a unit length “u” of the conveyor, perhaps one inch or one centimeter. The angle subtended by the length “u” is:
[0000]
η
i
=
u
r
i
eq
.
(
22
[0070] The radial force pulling the conveyor into the groove over that angle “η” is:
[0000] T ri =T i sin η i eq. (23
[0000] The centrifugal force is:
[0000]
T
c
=
Wv
2
gr
i
eq
.
(
24
[0000] where
W is the conveyor weight per unit length “u” g is the gravitational constant, 32.2 ft/sec2 v is the velocity of the conveyor and r i is the radius of the i th groove
[0075] As a design criterion of sheave systems, a factor of safety of 10 between the radial force and the centrifugal force is common, yielding:
[0000] T ri ≧10T C eq. (25
[0000] thus defining either a maximum conveyor velocity or a minimum groove and sheave diameter. The maximum velocity imposes a maximum flowrate for a given conveyor/tubing size combination.
[0076] While the preferred embodiments shown use a vertical orientation, it is understood and contemplated that the invention may be utilized in a horizontal orientation without departing from the spirit of the invention.
[0077] It will be appreciated by those skilled in the art that changes could be made to the embodiments described above without departing from the broad inventive concept thereof. It is understood, therefore, that this invention is not limited to the particular embodiments disclosed, but it is intended to cover modifications within the spirit and scope of the present invention as defined by the appended claims. | The invention disclosed provides a drive head assembly for a fluid conveyor system that propels a fluid entraining conveyor through a well bore to carry fluids to the surface. The invention is comprised of a pair of synchronized follower wheels connected to a set of counter rotating sheaves. A fluid entraining conveyor is wrapped in a “figure-8” conveyor path around the sheaves in a plurality of coaxial grooves and around a distal sheave located in the fluid in the well bore. The coaxial grooves incorporate a unique shape which in conjunction with the wrap pattern provide improved tractive qualities and thus reduce tension in the conveyor and increase the durability of the conveyor. The conveyor can run at increased speeds and with no tension on the downward portion of the conveyor resulting in higher efficiency and less down time due to breakage. | 5 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a solid agent for separating carbon monoxide from a mixed gas containing carbon monoxide together with nitrogen, methane, carbon dioxide, hydrogen, etc. and also to a method for producing the agent.
2. Prior Art
Carbon monoxide is a basic raw material in synthetic chemistry and it is produced from coke and coal in water gas furnace, Winkler furnace, Lurgi furnace, Kopper's furnace, etc. It is also produced from natural gas and petroleum hydrocarbons using a steam reformation process and a partial oxidation process. In the foregoing process, the products are obtained in the form of a mixed gas containing carbon monoxide, hydrogen, carbon dioxide, methane, nitrogen, etc. The mixed gas thus obtained also contains a small amount of water. For example, the mixed gas has a composition of 35 to 40 percent carbon monoxide, 45 to 51 percent hydrogen, 4 to 5 percent carbon dioxide, 0.5 to 1.0 percent methane, 4 to 9 percent nitrogen and 1,000 to 20,000 ppm water. Likewise, carbon monoxide which is formed as a byproduct in iron mills, oil refineries or petrochemical plants is also in the form of a mixed gas.
For the use of such carbon monoxide as a raw material in synthetic chemistry, it is necessary to separate the carbon monoxide from the mixed gas.
Hydrogen is also an important raw material in the chemical industry and it is separated from various types of mixed gas or from waste gases of petrochemical plants, such as the waste gases from the process for dehydrogenation of the hydrocarbons. These waste gases frequently contain a small amount of carbon monoxide. Since the carbon monoxide is a poison to catalysts for reactions wherein hydrogen is used, it must be separated and removed. Also, these waste gases usually contain a small amount of water.
One method to separate and remove carbon monoxide from mixed gases is by means of a liquid which is a copper solution. This process involves the following steps. First, by applying a pressure of 150 to 200 atm to the mixed gas at room temperature, the carbon monoxide is separated and removed by letting it be adsorbed into the ammoniacal aqueous solution of cuprous formate or into a hydrochloric acid suspension of cuprous chloride. Then, by heating the copper solution under reduced pressure, the carbon monoxide is discharged and separated and the copper solution is regenerated. However, this cleaning process has certain shortcomings including a difficulty in controlling the operation for the prevention of the formation of precipitates, corrosion of the equipment, loss of solution and high contstruction costs due to the use of a high pressure.
On the other hand, a toluene solution of aluminium copper chloride (AlCuCl4) has an advantage that it is not affected by hydrogen, carbon dioxide, methane and nitrogen which are contained in the mixed gas and therefore, requires a low pressure to adsorb the carbon monoxide. Nevertheless, it is defective in that it reacts irreversibly with water thereby causing deterioration in the adsorbing power of the solution as well as creating precipitates with hydrochloric acid. Consequently, it is necessary to provide a strong dehydration process prior to the adsorption process in order to reduce the water content in the mixed gas to less than 1 ppm. Strict control of the amount of water is indispensable to this procedure. Furthermore, the use of this adsorbing solution has another disadvantage. That is, the mixing of the vapor of toluene used as the solvent into the collected carbon monoxide is unavoidable, making it necessary to further provide equipment for the removal of the toluene. Also, because of the use of a liquid form of adsorbent, restrictions are placed on the processing procedure.
Now, few solid form of adsorbents for carbon monoxide have been known. According to U.S. Pat. No. 4,019,879, copper (I) zeolite that is obtained by a reduction process conducted at a high temperature after having copper (II) ions adsorbed by the zeolite is capable of adsorbing the carbon monoxide. This adsorbent, however, has drawbacks in that the temperature required for its preparation is as high as 300° to 350° C. and that the dependence of the amount of carbon monoxide adsorbed upon the pressure and temperature is relatively small.
In addition to the above, various methods have been proposed, but none of them have proved satisfactory as the process for separating carbon monoxide from mixed gas.
SUMMARY OF THE INVENTION
Accordingly, it is the general object of the present invention to provide a simple and economical method for producing a solid form adsorbent for carbon monoxide that enables separation of carbon monoxide directly from mixed gas.
The carbon monoxide adsorbent obtained in accordance with the present invention is a solid material that is prepared by the following steps. First, a compound selected from the group of copper (I) halide; copper (I) oxide; copper (II) halide, carboxylate, sulfate, nitrate, basic salt or ammine complex salt; or copper (II) oxide is mixed into a solvent in order to form a solution or suspension. Active carbon is added to the solution or the suspension. Then, the solvent is removed using a process such as evacuation, distillation, etc.
The solid form adsorbent for carbon monoxide obtained is resistant to the water included in the mixed gas and is capable of separating the carbon monoxide directly from the mixed gas containing water, without forming corrosive gases, etc. Also, the separated carbon monoxide does not contain the solvent vapor from the carbon monoxide adsorbent making it unnecessary to provide the equipment to collect the solvent vapor.
Since the carbon monoxide adsorbent produced according to the present invention is solid, it can be handled conveniently. Furthermore, as the means for separation of carbon monoxide, it is possible to use packed tower systems, packed column systems, fluidized bed systems, etc. Furthermore, the method for producing this solid carbon monoxide adsorbent is simple and can use various materials easily obtainable. Hence, the preparation of a useful carbon monoxide adsorbent is facilitated by the process provided by the present invention.
DETAILED DESCRIPTION OF THE INVENTION
Hereunder, the present invention will be described in detail in conjunction with the actual examples.
Copper (I) halides referred to in this invention include copper (I) chloride, copper (I) fluoride, copper (I) bromide and copper (I) iodide. Also, copper (I) oxide may be used.
Copper (II) halides referred to in this invention include copper (II) chloride, copper (II) fluoride, copper (II) bromide and copper (II) iodide.
Copper (II) carboxylates referred to in this invention include copper (II) acetate and copper (II) formate.
Copper (II) basic salts referred to in this invention include basic copper (II) carbonate, basic copper (II) acetate, basic copper (II) phosphate.
Copper (II) ammine complex salts referred to in this invention include hexammine copper (II) chloride.
Active carbon used in this invention includes formed carbon, granulated carbon composed of crushed carbon and powdered carbon. As the starting material for the active carbon, wood, coconut husk, coal, petroleum pitch, etc. are used. As the method for activation of the carbon, activation systems using chemicals, gases, etc. can be used.
Solvents which can be used in this invention are water, aqueous solution containing hydrochloric acid or ammonium formate, primary or secondary alcohol having 1 to 7 carbon atoms, acetone, ethyl acetate, formic acid, acetic acid, benzene, toluene, propionitrile, acetonitrile and aqueous ammonica.
The ratio by weight of active carbon to copper (I) halide or copper (I) oxide used in the production of the carbon monoxide adsorbent according to the present invention is 0.5 to 60.0 with the preferred ratio by weight being 3.0 to 10.0. The ratio by weight of solvent to copper (I) halide or copper (I) oxide used is 3 to 200, and preferably 5 to 30.
The ratio by weight of active carbon to coper (II) salts or copper (II) oxide used according to the present invention is 0.5 to 60.0, and preferably 2.0 to 10.0. The ratio by weight of solvent to copper (II) salts or copper (II) oxide used is 1 to 200, and preferably 3 to 30.
The ambience used in this invention for the production of the adsorbent for carbon monoxide is nitrogen, helium, argon or air.
The time for mixing copper (I) halide, copper (I) oxide, copper (II) salts or copper (II) oxide in the solvent used in this invention is from one minute to ten hours, and preferably one to three hours. The temperature for stirring the mixture is between 10° and 80° C., with a preferred range of 20° to 30° C.
In this invention, the interval between the addition of the active carbon into the solution or the suspension of copper (I) halide, copper (I) oxide, copper (II) salts or copper (II) oxide and the start of removal of the solvent is from one minute to ten hours, and preferably one to three hours. The temperature during the time when the active carbon is in the solution is between 10° and 80° C., and preferably 20° to 30° C. Stirring the solution or suspension is desirable.
Furthermore, the evacuation for the removal of the solvent according to this invention is 10 -6 to 10 -2 mmHg and preferably 10 -2 to 10 mmHg. The temperature at which the evacuation is performed is between 10° and 500° C. and preferably 80° to 250° C.
Furthermore, the carbon monoxide adsorbent, expecially in the type of copper (II) salts or copper (II) oxide can be more activated by applying heat to 30°-250° C., preferably 100° to 150° C. in reducing atmosphere, for example in carbon monoxide, hydrogen, etc. And further, the adsorbent in this type is resistance to sulfur compounds in the mixed gas and is capable of separating the carbon monoxide directly from the mixed gas containing sulfur compounds such as hydrogen sulfide, carbonyl sulfide, sulfur dioxide.
As will be demonstrated in the following examples, the carbon monoxide adsorbent obtained by following the teachings of the present invention quickly adsorbs carbon monoxide when it is exposed to mixed gas at one atm at a temperature between 0° and 40° C. The adsorbed carbon monoxide can be readily separated and discharged either by heating the carbon monoxide adsorbent to above 60° C. or by lowering the partial pressure of the carbon monoxide or both.
A further detailed description will hereunder given of the adsorbent for carbon monoxide and the method for producing the same with reference to the following examples.
EXAMPLE 1
In this example, for the copper (I) chloride, a special grade reagent from Koso Kagaku Yakuhin Co., Ltd. was used. For the hydrochloric acid, first grade reagent from Takahashi Tokichi Shoten was used after diluting it to 3N solution using purified water produced by Tokyo Yakuhin Kogyosho Co., Ltd. As the activated carbon, BAC, G-70R, Lot No. 810117 from Kureha Kagaku Co., Ltd. was used after giving it the following preliminary treatment. That is, it was heated to 180° C. and kept at this temperature for four hours under reduced pressure (6 mmHg) and then stored in dry nitrogen. The carbon monoxide gases and nitrogen gas used were cylinder gases produced respectively by Takachiho Kagaku Co., Ltd. (99.95% purity) and Suzuki Shokan Co., Ltd. (99.999% purity). Immediately prior to use, the gases were dried and purified by passing them through a packed tower Molecular Sieve 3A produced by Nikka Seiko Co., Ltd.
In an atmosphere of dry nitrogen, 1.5 g (15.2 m mol) of copper (I) chloride was placed in a 100 ml capacity double ported eggplant shaped flask; then, 15 ml of 3N hydrochloric acid was added while being stirred with a magnetic agitator. The mixture was kept at 20° C. for one hour. Into the eggplant shaped flask, 10 g of active carbon was added in an atmosphere of dry nitrogen. Then, after continuously stirring for one hour, the inside of the eggplant shaped flask was evacuated to 6 mm Hg and kept at 100° C. in order to remove the water and hydrogen chloride thoroughly. As a result, black grains were obtained. These black grains were the solid adsorbent of carbon monoxide.
The carbon monoxide adsorbent was introduced into a 100 ml double ported flask, which was connected to a container wherein 1.5 l of 1 atm mixed gas of carbon monoxide and nitrogen (0.9 atm of partial pressure of carbon monoxide and 0.1 atm of partial pressure of nitrogen) is contained. While stirring using a magnetic agitator, the adsorption of the carbon monoxide was carried out at 20° C. For ten minutes during the initial period of the adsorption, the mixed gas was circulated and passed over the adsorbent using a BA-106 T Model air pump manufactured by Iwaki Co., Ltd. The amount of carbon monoxide adsorbed was determined by means of a gas buret method at 20° C. The absorption of carbon monoxide occurred quickly with 6.4 m mol carbon monoxide adsorbed after three minutes. After sixty minutes, the carbon monoxide adsorbed amounted to 11.7 m mol and equilibrium in the amount of adsorption was nearly reached.
Next, the adsorbent was heated to 120° C. at 1 atm and the amount of gas discharged was determined using the gas buret method. The carbon monoxide was discharged quickly and the released amount became 11.7 m mol after ten minutes. The result of the analysis of the released gas using gas chromatography showed that the gas discharged was carbon monoxide with no other component detected.
Thereafter, the double ported eggplant shaped flask was connected to the container containing 1.5 l of 1 atm mixed gas composed of carbon monoxide and nitrogen (0.9 atm of partial pressure of carbon monoxide and 0.1 atm of partial pressure of nitrogen). The mixed gas was circulated over the adsorbent by means of an air pump while stirring with a magnetic agitator and the re-adsorption of carbon monoxide was performed at 20° C. Carbon monoxide was again adsorbed quickly with 6.6 m mol of carbon monoxide adsorbed after three minutes. The carbon monoxide adsorbed after 60 minutes amounted to 11.7 m mol and reached equilibrium. Furthermore, when the adsorbent was thereafter heated to 120° C., the carbon monoxide was discharged quickly and the amount released became 11.7 m mol afte ten minutes.
Following the above, even when the process of adsorption and discharge described above was performed repeatedly, no change was observed in the rate of adsorption of carbon monoxide as well as in the amount of carbon monoxide adsorbed.
Next, 5 l of 1 atm nitrogen gas containing 27 mg (1.5 m mol) of water (7,400 ppm in concentration of water) was prepared separately. The container with the above described nitrogen gas was connected to a 100 ml capacity double ported eggplant shaped flask. By using the BA-106 T Model air pump from Iwaki Co., Ltd., the nitrogen gas with water was circulated and passed over the adsorbent stirred by the magnetic agitator at 20° C. for ten minutes.
Then, while stirring the adsorbent at 20° C. using the magnetic agitator, the flask containing the adsorbent was connected to a container containing 1.5 l of 1 atm mixed gas of carbon monoxide and nitrogen (0.9 atm of partial pressure of carbon monoxide and 0.1 atm of partial pressure of nitrogen). The mixed gas was circulated over the adsorbent using the air pump. The adsorption went on rapidly and reached 11.7 m mol of carbon monoxide in 60 minutes. In other words, the rate of adsorption of carbon monoxide and the amount of carbon monoxide adsorbed showed almost no change in value from those prior to the exposure of the adsorbent to the gas containing 7,400 ppm of water.
EXAMPLE 2
Taking the same procedure as described in Example 1, the carbon monoxide adsorbent composed of 1.5 g (15.2 m mol) of copper (I) chloride and 10 g of active carbon was prepared. The adsorbent thus prepared was placed in a 100 ml capacity double ported eggplant shaped flask, which was to a container wherein 1.5 l of 1 atm mixed gas made up of carbon monoxide and nitrogen (0.9 atm in partial pressure of carbon monoxide and 0.1 atm of partial pressure of nitrogen) was contained. While stirring using a magnetic agitator, the adsorption of carbon monoxide occurred at 20° C. For ten minutes during the initial period of adsorption, the mixed gas was circulated and passed over the adsorbent using the BA-106 T Model air pump manufactured by Iwaki Co., Ltd. The amount of carbon monoxide adsorbed was determined at 20° C. using the gas buret method.
The adsorption of carbon monoxide occurred quickly and amounted to 6.6 m mol of carbon monoxide after three minutes. The amount of carbon monoxide adsorbed during sixty minutes became 11.7 m mol and reached nearly equilibrium.
Next, by using a vacuum pump, the inside of the double ported eggplant shape flask was evacuated to 6 mm Hg at 20° C. for ten minutes in order to release the adsorbed carbon monoxide.
Thereafter, the double ported eggplant shaped flask was connected to a container containing 1.5 l of carbon monoxide at 1 atm. While stirring with a mangetic agitator, the adsorption of carbon monoxide was carried out at 20° C. The adsorption of carbon monoxide occurred quickly and after three minutes, 7.0 m mol carbon monoxide was adsorbed. After sixty minutes, the amount of carbon monoxide adsorbed became 11.7 m mol and reached nearly equilibrium.
After the above, repetition of the same operation described resulted in no variation in the rate of adsorption of carbon monoxide and in the amount of carbon monoxide adsorbed.
EXAMPLE 3
The carbon monoxide solid adsorbent was prepared in the same manner as that described in Example 1 except that acetonitrile of a special grade from Wako Junyaku Kogyo Co., Ltd. was used instead of the 3N hydrochloric acid.
In an atmosphere of dry nitrogen, 1.5 g (15.2 m mol) of copper (I) chloride and 10 g of active carbon were introduced into a 100 ml capacity eggplant shaped flask equipped with a reflux condenser. Then, 15 ml of acetonitrile was added. While stirring using a magnetic agitator, the contents were heated to 90° C. and maintained at that temperature for one hour. Thereafter, the inside of the flask was evacuated to 6 mm Hg and heated to 100° C. to remove the acetonitrile thoroughly. As a result, black grains were obtained and these black grains were the solid adsorbent for carbon monoxide.
Using the same operation as described in Example 1, the amount of carbon monoxide adsorbed was determined. The amount of carbon monoxide adsorbed became 3.7 m mol after three minutes and became 6.2 m mol after sixty minutes to reach nearly equilibrium.
Next, the adsorbent was heated to 120° C. at 1 atm and the amount of gas released was determined by means of the gas buret method. The carbon monoxide was discharged quickly amounting to 6.1 m mol after ten minutes. Gas chromatography analysis of the discharged gas showed that the released gas was carbon monoxide with no other component.
Then, the double ported eggplant shaped flask was connected to a container containing 1.5 l of 1 atm mixed gas of carbon monoxide and nitrogen (0.9 atm of partial pressure of carbon monoxide and 0.1 atm of partial pressure of nitrogen). The mixed gas was circulated over the adsorbent using an air pump while stirring with a magnetic agitator and the re-adsorption of carbon monoxide was carried out at 20° C. The carbon monoxide was adsorbed quickly amounting to 3.7 m mol after three minutes. After sixty minutes, the amount of carbon monoxide adsorbed became 5.8 m mol to reach nearly equilibrium. The foregoing adsorbent was then heated to 120° C. with the result that the carbon monoxide was discharged quickly and amounted to 5.8 m mol after ten minutes.
Even when the adsorption and discharge procedure was repeated, no variation occurred in the rate of the adsorption of the carbon monoxide as well as in the amount of carbon monoxide adsorbed.
EXAMPLE 4
The solid carbon monoxide adsorbent was again prepared as described in Example 1 except 15 ml of purified water from Tokyo Yakuhin Kogyosho Co. Ltd. was used instead of 15 ml of 3N hydrochloric acid. Otherwise the reagents were the same as in Example 1. Taking the same procedure as described in Example 1, the adsorption of the carbon monoxide was carried out and the amount of carbon monoxide adsorbed was determined. It was found that the amount of carbon monoxide adsorbed during the first three minutes was 4.7 m mol and the amount adsorbed after sixty minutes was 6.7 m mol to reach nearly equilibrium.
Next, when the adsorbent was heated to 120° C. at 1 atm, the carbon monoxide was released quickly and the amount of carbon monoxide discharged reached to 6.7 m mol after ten minutes. An analysis of the discharge gas using gas chromatography showed that the discharged gas was carbon monoxide without other components.
Then, the re-adsorption of carbon monoxide was performed in the same manner described in Example 1. The adsorption of carbon monoxide occurred rapidly with 4.3 m mol of carbon monoxide adsorbed after three minutes. The amount of carbon monoxide adsorbed after sixty minutes amounted to 6.7 m mol and reached nearly equilibrium. Thereafter, the adsorbent was heated to 120° C. with the result that the carbon monoxide was discharged rapidly and amounted to 6.7 m mol after ten minutes.
Thereafter, even when the adsorption and discharge process were repeatedly done, the rate of adsorption of carbon monoxide and the amount of carbon monoxide adsorbed remained constant.
EXAMPLE 5
The solid carbon monoxide was again prepared in the same manner as Example 1 except that instead of 10 g of active carbon (BAC, G-70R), 10 g of active carbon from Takeda Yakuhin Kogyo Co., Ltd., Granular Shirasagi C 2 X 4/6-3, SGW-079, which is produced from coconut husk charcoal as the raw material and activated by steam was used. Other than the above, the same reagents as in Example 1 was used.
In an atmosphere of dry nitrogen, 1.5 g (15.2 m mol) of copper (I) chloride was placed in a 100 ml capacity double ported eggplant shaped flask. Then, 15 ml of 3N hydrochloric acid was added. The mixture was stirred by a magnetic agitator at 20° C. for two hours. Into the eggplant shaped flask, 10 g of the active carbon was added in an atmosphere of dry nitrogen. After stirring continuously for two hours, the pressure in the eggplant shaped flask was reduced to 6 mm Hg. The content was also heated to 120° C. and maintained at that temperature in order to remove the water and hydrogen chloride thoroughly. As a result, black grains were obtained and these black grains were the adsorbent for carbon monoxide.
Following the same procedure as used in Example 1, the amount of carbon monoxide adsorbed was determined. The amount of carbon monoxide adsorbed in the first three minutes amount to 5.6 m mol and after sixty minutes 6.2 m mol.
Next, the adsorbent was heated to 120° C. at 1 atm and the carbon monoxide discharged quickly. The amount of carbon monoxide released was 6.2 m mol after ten minutes. Gas chromatography analysis of the released gas indicated that the gas discharged was carbon monoxide with no other component.
EXAMPLE 6
The solid carbon monoxide adsorbent was again prepared in the same manner as Example 1 except that 28 percent aqueous ammonia which is a first grade reagent from Takahashi Tokichi Shoten was used instead of the 15 ml of 3N hydrochloric acid described in Example 1. Otherwise the same reagents as in Example 1 was used.
In an atmosphere of dry nitrogen, 1.5 g (15.2 m mol) of copper (I) chloride was introduced into a 100 ml capacity double ported eggplant shaped flask. Then, 20 ml of the aqueous ammonia was added. The mixture was stirred by a magnetic agitator for one hour at 20° C. Into the foregoing eggplant shaped flask, 10 g of active carbon was added in an atmosphere of dry nitrogen and the contents of the flask were further stirred continuously for one hour. Thereafter, the inside of eggplant shaped flask was evacuated to 6 mm Hg and kept at 80° C. by heating in order to remove the aqueous ammonia thoroughly. As a result, black grains were obtained and these black grains were the carbon monoxide adsorbent.
Using the same procedure as in Example 1, the amount of carbon monoxide adsorbed was determined. The result showed that after three minutes, 7.8 m mol of carbon monoxide was adsorbed while after sixty minutes 10.4 m mol of carbon monoxide was adsorbed. Next, when the adsorbent was heated to 120° C. at 1 atm, carbon monoxide was released quickly and 10.4 m mol of carbon monoxide was released after 10 minutes. The released gas was analyzed by means of gas chromatography and was found that the gas discharged was carbon monoxide with no other components:
EXAMPLE 7
The solid carbon monoxide adsorbent was again compared in the same manner as in Example 1 except that 1.1 g (7.6 m mol) of copper (I) oxide from Koso Kagaku Yakuhin Co., Ltd. was used instead of 15.2 m mol of copper (I)chloride in Example 1. Otherwise, the same reagents as in Example 1 were employed. Taking the same procedure as described in Example 1, the adsorption of the carbon monoxide was carried out and the amount of carbon monoxide adsorbed was determined with the result that 4.6 m mol of carbon monoxide was adsorbed after three minutes and 5.4 m mol of carbon monoxide was adsorbed after sixty minutes. Next, the adsorbent was heated to 120° C. at 1 atm to discharge carbon monoxide. The carbon monoxide was discharged quickly and amounted to 5.4 m mol after ten minutes. Analysis by gas chromatography of the released gas showed that the discharge gas was carbon monoxide with no other component identified.
EXAMPLE 8
The same reagents as those used in Example 1 are utilized in this example and the solid carbon monoxide adsorbent was prepared as described in Example 1 except that both the charge of 1.5 g of copper (I) chloride and that of 10 g of active carbon into the eggplant shaped flask were carried out in an atmosphere of air instead of in an atmosphere of dry nitrogen.
By employing the same procedure as in Example 1, the amount of carbon monoxide adsorbed was determined. The amount of carbon monoxide adsorbed after three minutes was 8.0 m mol and after sixty minutes the amount of carbon monoxide adsorbed was 10.1 m mol. Next, when the adsorbent was heated to 120° C. at 1 atm, the carbon monoxide was discharged at a high rate and amounted to 10.1 m mol after ten minutes. Analysis of the discharged gas using gas chromatography showed that the gas released was carbon monoxide with no other components.
EXAMPLE 9
The solid carbon monoxide adsorbent was again prepared in the same manner as in Example 1 except copper (I) bromide from Yoneyama Yakuhin Kogyo Co., Ltd. was used instead of 15.2 m mol of copper (I) chloride of Example 1. Also, 28 percent aqueous ammonia from Takahashi Tokichi Shoten was used instead of 15 ml of 3N hydrochloric acid. Otherwise, the same reagents were used as in Example 1.
In at atmosphere of dry nitrogen, 2.2 g (15.2 m mol) of copper (I) bromide was added into a 100 ml capacity double ported eggplant shaped flask. Then, 15 ml of aqueous ammonia was added. The mixture was stirred using a magnetic agitator at 20° C. for one hour. Into the eggplant shaped flask was then added 10 g of activated carbon in an atmosphere of dry nitrogen and the stirring was continued for one hour. Thereafter, the pressure in the eggplant shaped flask was reduced to 6 mm Hg and by keeping the temperature at 100° C., the aqueous ammonia was removed thoroughly. The resulted product was the carbon monoxide adsorbent in the form of black grains.
By utilizing the same procedure as in Example 1, the amount of carbon monoxide adsorbed was determined. The amount of carbon monoxide adsorbed after three minutes was 5.7 m mol and after sixty minutes was 9.4 m mol. Next, the adsorbent was heated to 120° C. at 1 atm. This caused the carbon monoxide to be released at a high rate. The amount of carbon monoxide thus released was 9.4 m mol after ten minutes. Gas chromatographic analysis of the discharged gas showed that the gas released was carbon monoxide with no other components.
EXAMPLE 10
In this example, copper (I) oxide produced by Kose Kagaku Yakuhin Co., Ltd. was used. For the aqueous ammonia, first grade reagent 28 percent aqueous ammonia from Takahashi Tokichi Shoten was utilized. Formic acid of a special grade produced by Nakarai Kagaku Yakuhin Co., Ltd. was used and the active carbon, carbon monoxide gas and nitrogen gas used were same as those used in Example 1.
In at atmosphere of dry nitrogen, 1.1 g (7.6 m mol) of copper (I) oxide was introduced into a 100 ml capacity double ported eggplant shaped flask. Then, 5 ml of formic acid and 20 ml of aqueous ammonia were added. The mixture was stirred by a magnetic agitator at 20° C. for one hour. Into the eggplant shaped flask was introduced 10 g of active carbon in an atmosphere of dry nitrogen. After the contents of the flask were further stirred for one hour, the pressure in the eggplant shaped flask was reduced to 6 mm Hg with heating to 100° C. in order to remove the formic acid, ammonia and water thoroughly. The resulting product was in the form of black grain and was the adsorbent for carbon monoxide.
In accordance with the same method described in Example 1, the amount of carbon monoxide was determined. After three minutes, the carbon monoxide adsorbed was 6.7 m mol and after sixty minutes the amount of carbon monoxide adsorbed was 9.1 m mol. Next, the adsorbent was heated to 120° C. at 1 atm. As a result, the carbon monoxide was released quickly and amounted to 9.1 m mol after ten minutes. An analysis by gas chromatography conducted on the discharged gas revealed that the gas released was carbon monoxide and no other components were detected.
EXAMPLE 11
In this example, copper (I) chloride of a special grade reagent from Komune Kagaku Yakuhin Co., Ltd. was used. Also, ammonia formate of the first reagent grade from Koso Kagaku Yakuhin Co., Ltd was used. As the 28 percent of aqueous ammonia a first grade reagent produced by Takahashi Tokichi Shoten was used. Otherwise, for the active carbon, carbon monoxide gas and nitrogen gas, the same ones as those used in Example 1 were used.
In the atmosphere of dry nitrogen, 1.5 g (15.2 m mol) of copper (I) chrolide and 3 g (47.6 m mol) of ammonia formate were introduced into a 100 ml capacity double ported eggplant shaped flask. Then, 15 ml of aqueous ammonia was added. The mixture stirred by a magnetic agitator was left at 20° C. for one hour. Into the eggplant shaped flask was then introduced 10 g of active carbon in an atmosphere of dry nitrogen. After the contents of flask were further stirred for one hour, the inside pressure of the eggplant shaped flask was reduced to 6 mm Hg with heating to 180° C. so that the aqueous ammonia and water were removed thoroughly leaving black grains. These black grains are the adsorbent for carbon monoxide.
Through the same method as described in Example 1, the amount of carbon monoxide adsorbed was determined. The amount of carbon monoxide adsorbed in three minutes was 7.3 m mol and after sixty minutes the amount of carbon monoxide adsorbed was 9.3 m mol. Next, the adsorbent was heated to 120° C. at 1 atm. The carbon monoxide was released quickly and reached 9.3 m mol by the end of ten minutes. An analysis of the released gas by gas chromatography showed that the gas discharged was carbon monoxide and no other components were identified.
EXAMPLE 12
In this example, for the copper (II) chloride, a special grade reagent from Koso Kagaku Yakuhin Co., Ltd. was used. The purified water from Tokyo Yakuhin Kogyosho Co., Ltd. was used and the active carbon, carbon monoxide gas and nitrogen gas used were the same as those usd in Example 1.
In an atmosphere of dry nitrogen, 2.6 g (15.0 m mol) of copper (II) chloride was placed in a 100 ml capacity double ported eggplant shaped flask; then, 15 ml of purified water was added while being stirred with a magnetic agitator. The mixture was kept at 20° C. for one hour. Into the eggplant shaped flask, 10 g of active carbon was added in the atmosphere of dry nitrogen. Then, after the contents of the flask were further stirred for one hour, the inside of the eggplant shaped flask was evacuated to 6 mm Hg and kept at 100° C. by heating in order to remove the water thoroughly. As a result, black grains were obtained. These black grains thus obtained were the solid adsorbent of carbon monoxide. Taking the same procedure described in Example 1, the amount of carbon monoxide adsorbed was determined by means of a gas buret method at 20° C. The adsorption of carbon monoxide occurred quickly with 3.3 m mol carbon monoxide adsorbed after three minutes. After sixty minutes, the carbon monoxide adsorbed amounted to 4.3 m mol and reached nearly equilibrium.
Next, by using a vacuum pump, the inside of the double ported eggplant shaped flask was evacuated to 0.4 mm Hg at 20° C. for ten minutes in order to release the adsorbed carbon monoxide. Then, the re-adsorption of carbon monoxide was performed in the same manner as described in Example 1. The adsorption of carbon monoxide occurred rapidly with 3.3. m mol of carbon monoxide adsorbed after three minutes. The amount of carbon monoxide adsorbed after sixty minutes amounted to 4.3 m mol and reached nearly equilibrium.
Thereafter, the inside of the double ported eggplant shaped flask was again evacuated to 0.4 mm Hg at 20° C. for ten minutes by using a vacuum pump and the adsorbed carbon monoxide was released.
Following the above, even when the process of adsorption and discharge described above was performed repeatedly, no change was observed in the rate of adsorption of carbon monoxide as well as in the amount of carbon monoxide adsorbed.
EXAMPLE 13
Taking the same procedure as described in Example 12, the carbon monoxide adsorbent composed of 2.6 g (15.0 m mol) of copper (II) chloride and 10 g of active carbon was prepared. In accordance with the method described in Example 1, the adsorption of carbon monoxide was carried out and the amount of carbon monoxide adsorbed was determined at 20° C. using the gas buret method. The amount of carbon monoxide adsorbed in the first three minutes amounted to 3.3 m mol and after sixty minues 4.3 m mol.
Next, the adsorbent was heated to 120° C. at 1 atm and the carbon monoxide was released quickly. The amount of carbon monoxide discharged amount to 4.3 m mol after ten minutes. An analysis of the discharged gas using gas chromatography showed that the discharged gas was carbon monoxide with no other components.
Then, the re-adsorption of carbon monoxide was performed in the same manner as described in Example 1. The adsorption of carbon monoxide occurred rapidly with 4.9 m mol of carbon monoxide adsorbed after three minutes and 5.9 m mol of carbon monoxide was adsorbed after sixty minutes.
Thereafter, the adsorbent was again heated to 120° C. and the carbon monoxide was released quickly. The amount of carbon monoxide discharged amounted to 5.9 m mol after ten minutes.
Furthermore, the re-adsorption of carbon monoxide was again performed in the same manner as described in Example 1. The adsorption occurred rapidly and 5.9 m mol of carbon monoxide was adsorbed after sixty minutes.
Next, the adsorbent was again heated to 120° C. at 1 atm. The carbon monoxide was released quickly and the amount discharged was 5.9 m mol after ten minutes. An analysis of the discharge gas using gas chromatography showed that the discharge gas was carbon monoxide with no other component identified.
Even when the process of adsorption and discharge described above was performed repeatedly, no change was observed in the rate of adsorption of carbon monoxide as well as in the amount of carbon monoxide adsorbed.
EXAMPLE 14
The solid adsorbent composed of 2.6 g (15.0 m mol) of copper (II) chloride and 10 g of active carbon was prepared in the same manner as described in Example 12. The resulting carbon monoxide adsorbent was used after incubation at 120° C. for thirty minutes in an atmosphere of carbon monoxide.
Taking the same procedure described in Example 1, the adsorption of carbon monoxide in the mixed gas of carbon monoxide and nitrogen was carried out and the amount of carbon monoxide adsorbed was measured at 20° C. using the gas buret method. The adsorption occurred quickly and 5.0 m mol of carbon monoxide was adsorbed after three minutes while 5.8 m mol was adsorbed after sixty minutes.
Next, the adsorbent was heated to 120° C. at 1 atm and the amount of carbon monoxide discharged was determined. The carbon monoxide was released quickly and after ten minutes the amount discharged was 5.8 m mol. The gas chromatography analysis showed that the discharge gas was carbon monoxide with no other component identified.
The re-adsorption of carbon monoxide was performed in the same manner as described in Example 1. The adsorption of carbon monoxide occurred rapidly. After three minutes, 4.9 m mol of carbon monoxide was adsorbed and 5.7 m mol of carbon monoxide was adsorbed after sixty minutes.
Thereafter, the adsorbent was again heated to 120° C. and the carbon monoxide was released quickly. The amount discharged was 5.7 m mol after 10 minutes.
No change was observed in the rate of adsorption of carbon monoxide as well as in the amount of carbon monoxide adsorbed, even when the process of adsorption and discharge described above was performed repeatedly.
EXAMPLE 15
The carbon monoxide adsorbent was prepared by heating the solid adsorbent obtained in the same manner as described in Example 12 to 100° C. for one hour in an atmosphere of hydrogen.
Using the same method as in Example 1, the amount of carbon monoxide adsorbed was determined. 4.5 m mol of carbon monoxide was adsorbed after three minutes and 5.6 m mol adsorbed after sixty minutes.
Next, by using a vacuum pump, the inside of the double ported eggplant shaped flask was evacuated to 0.4 mm Hg at 20° C. for ten minutes to release the adsorbed carbon monoxide.
Then, the re-adsorption of carbon monoxide was performed in the same manner as described in Example 1. The carbon monoxide was rapidly adsorbed with the amount of 4.5 m mol after three minutes and the amount of 5.6 m mol after sixty minutes.
Thereafter, the adsorbed carbon monoxide was again released by evacuating again the inside of the flask to 0.4 mm Hg at 20° C. for ten minutes by using a vacuum pump.
Further repeated process of adsorption and discharge described above showed no change in the rate of adsorption as well as in the amount of adsorped carbon monoxide.
EXAMPLE 16
The carbon monoxide adsorbent subjected to heat treatment in the atmosphere of carbon monoxide in the same manner as described in Example 14 was used.
The amount of carbon monoxide adsorbed was determined in the same method as in Example 1. After three minutes, 5.0 m mol of carbon monoxide was adsorbed and after sixty minutes 5.8 m mol adsorbed was.
Next, the adsorbent was heated to 120° C. at 1 atm and the carbon monoxide adsorbed was rapidly released. The amount discharged after ten minutes was 5.8 m mol.
Thereafter, the adsorbent was kept at 20° C. in 1 atm hydrogen sulfide for sixteen hours. The amount of carbon monoxide re-adsorbed was determined using the same method as described in Example 1. 1.6 m mol of carbon monoxide was adsorbed after three minutes, 5.8 m mol adsorbed after ten minutes and 6.0 m mol adsorbed after sixty minutes.
Then, the adsorbed carbon monoxide was released by evacuating the inside of the flask to 0.4 mm Hg at 20° C. for ten minutes by using a vacuum unit.
Further, the re-adsorption of carbon monoxide was performed in the same manner as in Example 1 and the amount of carbon monoxide adsorbed was determined. After three minutes, 5.0 m mol of carbon monoxide was adsorbed, and after sixty minutes 6.0 m mol was adsorbed.
Hence, the adsorption activity of the adsorbent was little affected after being subjected to the hydrogen sulfide.
EXAMPLE 17
The carbon monoxide adsorbent was again prepared in the same manner as in Example 12 except copper (II) bromide from Yoneyama Yakuhin Kogyo Co., Ltd. was used instead of 15.0 m mol of copper (II) chloride of Example 12. Also, methanol of a special grade reagent produced by Nakarai Kagaku Yakuhin Co., Ltd. was used instead of 15 ml of purified water.
In an atmosphere of dry nitrogen, 3.4 g (15.0 m mol) of copper (II) bromide was added into a 100 ml capacity double ported eggplant shaped flask. Then, 15 ml of methanol was added. The mixture was stirred using a magnetic agitator at 20° C. for one hour. Into the eggplant shaped flask was then added 10 g of active carbon in an atmosphere of dry nitrogen and the stirring was continued for one hour. Thereafter, the pressure in the eggplant shaped flask was reduced to 6 mm Hg at 100° C. and the methanol was removed thoroughly. The resulted product was the carbon monoxide adsorbent in the form of balck grains.
By utilizing the same procedure as in Example 1, the amount of carbon monoxide adsorbed was determined. The amount of carbon monoxide adsorbed after three minutes was 2.8 m mol and after sixty minutes was 5.7 m mol. Next, the adsorbent was heated to 120° C. at 1 atm. The carbon monoxide was released rapidly. The amount of carbon monoxide thus released was 5.7 m mol after ten minutes. Gas chromatographic analysis of the discharged gas showed that the gas released was carbon monoxide with no other components.
EXAMPLE 18
Taking the same procedure as described in Example 12, the carbon monoxide adsorbent composed of 2.6 g (15.0 m mol) of copper (II) chloride and 10 g of active carbon was prepared.
In an atmosphere of dry nitrogen, 2.6 g (15.0 m mol) of copper (II) chloride was introduced into a 100 ml capacity double ported eggplant shaped flask. Then, 15 ml purified water was added. The mixture was stirred by a magnetic agitator at 20° C. for an hour. Into the eggplant shaped flask, 10 g of active carbon was then added in an atmosphere of air.
After the contents of the flask were further stirred for one hour, the pressure in the eggplant shaped flask was reduced to 6 mm Hg at 180° C. and the purified water was removed thoroughly. As a result, black grains were obtained and these black grains were the carbon monoxide adsorbents.
By using the same operation as described in Example 1, the amount of carbon monoxide adsorbed was determined. The amount of carbon monoxide adsorbed after three minutes was 6.9 m mol and the amount adsorbed after sixty minutes was 8.6 m mol.
Next, the adsorbent was heated to 120° C. at 1 atm. The carbon monoxide was released rapidly and the amount discharged was 8.6 m mol after ten minutes. Gas chromatography analysis showed that the gas released was carbon monoxide with no other components.
EXAMPLE 19
The carbon monoxide adsorbent was prepared by heating the solid adsorbent obtained in the same manner as described in Example 12 to 180° C. for one hour in an atmosphere of hydrogen.
Using the same method as in Example 1, the amount of carbon monoxide adsorbed was determined. The amount of carbon monoxide adsorbed after three minutes was 5.0 m mol and after sixty minutes was 7.9 m mol.
Next, the adsorbent was heated to 120° C. at 1 atm. The carbon monoxide was released rapidly and the amount released was 7.9 m mol after ten minutes. The gas released was carbon monoxide with no other components.
EXAMPLE 20
The solid adsorbent composed of 2.6 g (15.0 m mol) of copper (II) chloride and 10 g of active carbon was prepared in the same manner as described in Example 12 and the carbon monoxide adsorbent was used after incubation at 120° C. for thirty minutes in an atmosphere of carbon monoxide.
Taking the same procedure described in Example 1, the amount of carbon monoxide adsorbed from the mixed gas was measured. 5.0 m mol of carbon monoxide was adsorbed after three minutes and 5.8 m mol was adsorbed after sixty minutes.
Next, the adsorbent was heated to 120° C. at 1 atm and the amount of carbon monoxide released was determined. The carbon monoxide was released quickly and the amount released was 5.8 m mol after ten minutes. No component other than carbon monoxide was detected.
Furthermore, 5 liter of 1 atm nitrogen gas containing 27 mg (1.5 m mol) of water (7,400 ppm of water) was prepared separately. The container with said nitrogen gas was connected to a 100 ml capacity double ported eggplant shaped flask. Using the BA-106 T Model air pump manufactured by Iwaki Co., Ltd., the nitrogen gas was circulated and passed over the adsorbent at 20° C. for ten minutes while the adsorbent was stirred by the magnetic agitator.
Thereafter, while the adsorbent was stirred at 20° C. by a magnetic agitator, the flask was connected to a container containing 1.5 liter of 1 atm mixed gas composed of carbon monoxide and nitrogen (0.9 atm of partial pressure of carbon monoxide and 0.1 atm of partial pressure of nitrogen). Using an air pump, the mixed gas was circulated over the adsorbent in order to adsorb the carbon monoxide. The adsorption of carbon monoxide occurred rapidly with 5.8 m mol adsorbed in sixty minutes. As a result, the rate of adsorption of carbon monoxide and the amount of carbon monoxide adsorbed stayed unvaried even though the adsorbent was exposed to a gas containing 7,400 ppm of water.
EXAMPLE 21
The carbon monoxide adsorbent was prepared in the same manner as in Example 12 except copper (II) sulfate anhydride from Yoneyama Yakuhin Kogyo Co., Ltd. was used instead of 15.0 m mol of copper (II) chloride in Example 12.
In an atmosphere of dry nitrogen 2.4 g (15.0 m mol) of copper (II) sulfate anhydride was introduced into a 100 ml capacity double ported eggplant shaped flask. Then, 15 ml of purified water was added. The mixture was stirred by a magnetic agitator at 20° C. for one hour. Into the eggplant shaped flask was introduced 10 g of active carbon. After the contents of the flask were further stirred for one hour, the pressure in the eggplant shaped flask was reduced to 6 mm Hg at 100° C. to remove the water thoroughly. As a result, black grains were obtained. These black grains were the adsorbents for carbon monoxide.
Using the same method as in Example 1, the amount of carbon monoxide adsorbed was determined. After three minutes, 0.5 m mol of carbon monoxide was adsorbed and after sixty minutes 1.2 m mol of carbon monoxide was adsorbed. Next, the adsorbent was heated to 120° C. at 1 atm. The carbon monoxide was released quickly and 1.2 m mol of carbon monoxide was released after 10 minutes. The released gas was analyzed by means of gas chromatography and was found that the gas discharged was carbon monoxide with no other component.
EXAMPLE 22
The solid carbon monoxide adsorbent was again prepared in the same manner as in Example 12 except copper (II) oxide from MERCK was used instead of 15.0 m mol of copper (II) chloride. Also, 28 percent aqueous ammonia from Takahashi Tokichi Shoten was used instead of 15 ml of purified water. Otherwise, the same reagents were used as in Example 12.
In an atmosphere of dry nitrogen, 1.2 g (15.0 m mol) of copper (II) oxide was added into a 100 ml capacity double ported eggplant shaped flask. Then, 15 ml of aqueous ammonia was added. The mixture was stirred using a magnetic agitator at 20° C. for one hour. Into the eggplant shaped flask was then added 10 g of active carbon in an atmosphere of dry nitrogen and the stirring was continued for one hour. Thereafter, the pressure in the eggplant shaped flask was reduced to 6 mm Hg at 100° C. to remove aqueous ammonica thoroughly. The resulted product was the carbon monoxide adsorbent in the form of black grains.
By utilizing the same procedure as in Example 1, the amount of carbon monoxide adsorbed was determined. The amount of carbon monoxide adsorbed after three minutes was 0.9 m mol and after sixty minutes was 1.8 m mol. Next, the adsorbent was heated to 120° C. at 1 atm. The carbon monoxide was released rapidly. The amount of carbon monoxide thus released was 1.8 m mol after ten minutes. The gas released was carbon monoxide with no other components.
EXAMPLE 23
The carbon monoxide adsorbent was prepared in the same manner as in Example 12 except copper (II) sulfate anhydride from Yoneyama Yakuhin Kogyo Co., Ltd. was used instead of copper (II) chloride in Example 12. Also, 35 percent hydrochroric acid from Takahashi Tokichi Shoten was used instead of 15 ml of purified water.
In an atmosphere of dry nitrogen, 2.4 g (15.0 m mol) of copper (II) sulfate anhydride was added into a 100 ml capacity double ported eggplant shaped flask. Then, 15 ml of 30 percent hydrochroric acid was added. The mixture was stirred using a magnetic agitator at 20° C. for one hour. Into the eggplant shaped flask was then added 10 g of active carbon in an atmosphere of dry nitrogen and the stirring was continued for one hour. Thereafter, the pressure in the eggplant shaped flask was reduced to 6 mm Hg 100° C. to remove the water and hydrogen chloride thoroughly. The resulted product was the carbon monoxide adsorbent in the form of black grains.
By utilizing the same procedure as in Example 1, the amount of carbon monoxide adsorbed was determined. The amount of carbon monoxide adsorbed after three minutes was 3.0 m mol and after sixty minutes was 5.8 m mol. Next, the adsorbent was heated to 120° C. at 1 atm to release the carbon monoxide quickly. The amount released was 5.8 m mol and no other component than carbon monoxide was detected.
EXAMPLE 24
In this example, copper (II) oxide from MERCK was used instead of 15 m mol of copper (II) chloride in Example 12. Also, 35 percent hydrochloric acid from Takahashi Tokichi Shoten was used instead of 15 ml of purified water after diluting it to 5N solution using purified water from Tokyo Yakuhin Kogyosho Co., Ltd.
In an atmosphere of dry nitrogen, 1.2 g (15.0 m mol) of copper (II) oxide was placed in a 100 ml capacity double ported eggplant shaped flask. Then 15 ml of 5N hydrochloric acid was added while being stirred with a magnetic agitator. The mixture was kept at 20° C. for one hour. Into the eggplant shaped flask, 10 g of active carbon was added in an atmosphere of dry nitrogen. Then, after the stirring was continued for one hour, the pressure of the eggplant shaped flask was evacuated to 6 mm Hg at 100° C. in order to remove the water and hydrogen chloride thoroughly. As a result, black grains were obtained. These black grains thus obtained were the solid adsorbent of carbon monoxide.
Taking the same procedure described in Example 1, the amount of carbon monoxide adsorbed was determined. The amount of carbon monoxide adsorbed after three minutes was 1.5 m mol and after sixty minutes was 3.9 m mol. The adsorbent was heated to 120° C. at 1 atm and the carbon monoxide was released quickly. The amount released was 3.9 m mol after ten minutes. No other component than carbon monoxide was detected.
EXAMPLE FOR COMPARISON
The same reagents described in Example 1 were utilized. In an atmosphere of dry nitrogen, 1.5 g (15.2 m mol) of copper (I) chloride was introduced into 100 ml capacity double ported eggplant shaped flask. Then, 15 ml of 3N hydrochloric acid was added. The mixture was stirred by a magnetic agitator at 20° C. for one hour. Thereafter, the pressure in the eggplant shaped flask was reduced to 6 mm Hg at 100° C. to remove the water and hydrogen chloride thoroughly. As a result, a white powder was obtained.
The container having the white powder was connected to a container containing 1.5 l of 1 atm of mixed gas (0.9 atm of partial pressure of carbon monoxide and 0.1 atm of partial pressure of nitrogen). While stirring with the magnetic agitator, the white powder was placed in contact with the mixed gas at 20° C. For ten minutes during the initial period of contact, the mixed gas was circulated and passed over the white powder using the BA-106 T Model air pump manufactured by Iwaki Co., Ltd. The amount of carbon monoxide adsorbed was determined by means of the gas buret method. The amount of carbon monoxide adsorbed after sixty minutes was 0 m mol and almost no adsorption of carbon monoxide by the white powder was observed.
It should be apparent to those skilled in the art that the above described embodiments and examples are merely a few of the many possible specific embodiments and examples of the present invention. Numerous and varied other embodiments and examples are possible without departing from the spirit and scope of the invention. | A solid form adsorbent of carbon monoxide, that is obtained by the process including the following steps. First, copper salts or copper oxide is stirred in a solvent. Then, into the solution or suspension thus obtained, active carbon is added. Finally, the solvent is removed by means of pressure reduction, distillation, etc. The carbon monoxide adsorbent produced according to this invention adsorbs carbon monoxide rapidly when it is brought into contact with a mixed gas. The adsorbed carbon monoxide can be readily separated and discharged through either heating the carbon monoxide adsorbent to above 60° C. or reducing the partial pressure of carbon monoxide. The carbon monoxide obtained in accordance with the present invention is stable relative to the water content in the mixed gas, and it is capable of separating carbon monoxide directly from the mixed gas containing the water. Also, the separated carbon monoxide does not contain the vapor of the solvent from the carbon monoxide adsorbent. Therefore, it is not necessary to provide equipment to collect the solvent vapor. Furthermore, this carbon monoxide adsorbent does not produce corrosive gases, etc. The carbon monoxide adsorbent obtained by using copper (II) salts or copper (II) oxide is also stable relative to sulfur content in the mixed gas. | 2 |
[0001] The present invention relates to a method and devices for setting up a connection in a system for mobile telecommunications.
[0002] The demand for multi-media connections through networks for mobile telecommunications is increasing. However, not all terminals for mobile telecommunication support multi-media connections or their users do not own a subscription for multi-media service. Furthermore, a roaming subscriber may currently be located in a network wherein his multi-media subscription is not valid.
[0003] Another matter for handling more than one service is a possible service switching between at least two services during a connection. At said service switching the service used n a connection is changed for example from speech to multi-media and vice versa.
[0004] For these cases it is planned to enhance the current call set-up procedure, in particular the inter-working between a call control node and a database for storing subscriber data. The current procedure is described for example by Mouly, Pautet, The GSM System for Mobile Communications, 1992, page 523 and following. The enhancement enables to fall-back for example from a requested multi-media connection to a speech connection. Examples for a demand for said enhancement is the 3GPP standard TS. 23.172, Version 5.1.0, published December 2002. However, the document does not disclose how such fallback can be implemented at the inter-working between call control node and database.
[0005] Therefore it is object of the invention to provide a method and devices that provide an inter-working between call control node and a database for storing subscriber data that support the implementation of a fall-back at call set-up.
[0006] This will be solved advantageously by the method of claims 1 and 2 , the call control node of claim 6 and the database of claim 8 .
[0007] It is advantageous that an indication is sent that further request messages will sent. This enables the database to request a mobile station roaming number not more than once for one connection. Thus unnecessary reservations of mobile station roaming numbers are avoided.
[0008] Further advantageous is the return of an indication that the database is capable of handling said indicator. This enables to introduce databases operating according to the invention step by step into a network. It furthermore enables the inter-working between a call control node according to the invention and a database not operating according to the invention.
[0009] Further advantageous embodiments can be derived from the dependent claims.
[0010] Advantageous is the ability to send more than two request messages according to claim 2 . This enables to control the set up a connection with a higher granularity with respect to fall-back solutions.
SUMMARY
[0011] The invention introduces methods and devices that enable to request more than one service during call set-up, for example to enable a fall-back from a first preferred service to a second service if the first service is not applicable or to switch between services during a connection. To this end a new indicator is introduced into a request message sent to a database storing subscriber data, for indicating that at least one further request message is sent and a response indicator that a database is adapted to handle said indicator.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] The following figures show:
[0013] FIG. 1 depicts a part of a call set-up as state of the art,
[0014] FIG. 1 a depicts a part of a call set-up according to the invention,
[0015] FIG. 2 depicts the invented method as executed in a call control node,
[0016] FIG. 3 depicts the invented method as executed in a database for storing subscriber data,
[0017] FIG. 4 depicts a call control node according to the invention, and
[0018] FIG. 5 depicts a database for storing subscriber data according to the invention.
DETAILED DESCRIPTION OF THE INVENTION
[0019] In the following the invention will be further described by means of embodiments and by means of figures.
[0020] FIG. 1 depicts a part of a call set-up as state of the art. In a first step 1 , a gateway mobile services switching centre GMSC 1 receives a call request message, for example an initial address message. In a next step 2 , the gateway mobile services switching centre GMSC 1 send s a routing information request message, e.g. a send routing information message to a home location register HLR 1 . The home location register HLR 1 analyses the received message and determines from subscriber data that the requested service is permitted. It requests a mobile station roaming number from a mobile services switching centre MSC 1 that currently serves the called party in a next step 3 . The mobile services switching centre MSC 1 determines the requested mobile station roaming number and sends it to the home location register HLR 1 in a following step 4 . The home location register HLR 1 forwards the received number to the gateway mobile services switching centre GMSC 1 in a next step 5 . After the reception of the number, the gateway mobile services switching centre GMSC 1 sends a call request message to the mobile services switching centre MSC 1 in a last step 6 . The provision of a mobile station roaming number may also be executed by the home location register HLR 1 , wherein the contacting of the mobile services switching centre MSC 1 by the home location register HLR 1 is not performed, however, this alternative is currently not implemented.
[0021] FIG. 1 a shows a part of a call set-up according to the invention. A first call control node, e.g. a gateway mobile services switching centre, GMSC 2 receives a call set-up request message IAM 1 . The call set-up request message IAM 1 comprises an indication of a first and a second service. The first call control node GMSC 2 sends to a database for storing subscriber data a routing info request message SRI 1 , e.g. a send routing information message, comprising an identification of a called party, an indication of a service—for example a bearer capability—and an indication that a further request will be sent. The database for storing subscriber data HLR 2 determines that the requested service is permitted for the called party and sends a request PRN for a mobile station roaming number to a call control node MSC 2 that currently serves the called party. The call control node MSC 2 determines the requested number and sends it to the database for storing subscriber data in a return message PRNRes. The database for storing subscriber data sends a response message SRIRes 1 to the first call control node GMSC 2 comprising the mobile station roaming number and an indication that it is adapted to handle the indicator that at least one further request message will be sent. The first call control node GMSC 2 analyses the received response message and sends a second request message SRI 2 comprising an indication of the second further service—for example a bearer capability—and an indication that this is the second request to the database for storing subscriber data HLR 2 . The database for storing subscriber data HLR 2 analyses the received message, determines whether the requested service is permitted and returns a second response message SRIRes 2 . The first call control GMSC 2 node sends, based on an analysis of the received response messages SRI 1 and SRI 2 , a call set-up request message to a call control node, in this case the call control node MSC 2 serving the called party.
[0022] A call control node can be for example a mobile services switching centre or a gateway mobile services switching centre. A database for storing subscriber data can be for example a home location register, a home subscriber server or an AAA-server (Authentication, Authorisation and Accounting server).
[0023] FIG. 2 depicts the invented method as executed by a call control node. For the description of the following figures a gateway mobile services switching centre, and a home location register are selected as examples for a call control node and a database respectively, for explanation but not for limiting purposes. In a first step 200 the method is started. In a following step 201 , the gateway mobile services switching centre receives a call request—message, e.g. an initial address message. The call set-up request message comprises an indication of at least two services, a preferred service like multi-media and a fall-back service like speech for a connection towards a called party. In a next step 202 the gateway mobile services switching centre sends a routing information request message to a home location register. The routing information request message comprises an identification of the called party, an indication of a service—for example a speech bearer capability to indicate that a speech service is requested, and an indication that at least one further message will be sent—for example a newly introduced two step indicator.
[0024] In a preferred embodiment of the invention an indicator for a speech service is sent first and an indicator for a multi-media service is sent second as for the time being in a terminating mobile services switching centre a speech bearer can be overwritten by a multi-media bearer but not vice versa.
[0025] In a following step 203 the gateway mobile services switching centre receives a response message. It analyses the response message in a next step 204 and determines that it comprises an indication that the home location register is adapted to handle the indicator that at least one further request message will be sent.
[0026] In a next step 205 the gateway mobile services switching centre sends a further request for routing information comprising an indication of the second service. In a preferred embodiment of the invention this request further comprises an indication that this is a further request. The gateway mobile services switching centre receives a further response message in a next step 206 and analyses it in a following step 207 . The following results are possible:
a) If both response messages comprise a mobile station roaming number, the second number is discarded and the mobile services switching centre sends a call set-up request to a further call control node comprising an indication of both requested services. b) If the first response message comprises a mobile station roaming number and the second response message comprises a forwarded to number, a call set-up message is sent comprising an indication of only one of the requested services. The selection which of the service is indicated can be executed according to predefined user settings or operator settings. c) If the first response message comprises a mobile station roaming number and the second one comprises an indication that the requested service is not permitted for the called party, a call set-up message comprising an indication of the first service is sent. d) If the first response message comprises a forwarded to number and the second response message comprises a mobile station roaming number, a call set-up message comprising an indication of only one of the services is sent to the corresponding call control node. The selection which of the service is indicated can be executed according to predefined user settings or operator settings. e) If both response messages comprise a forwarded to number it depends whether it is the same number in both messages. If it is the same number a call set-up message is sent comprising an indication of both services, if not one of the services is selected as described above and a call set-up message is sent to the corresponding call control node. f) If a forwarded to number is received in the first response message and an indication that the second service is not permitted for the called party is received in the second response message, a call set-up message comprising an indication of the first service is sent to the corresponding call control node. g) If an indication that the requested service is not permitted for the called party is received in the first response message, and a mobile station roaming number or a forwarded to number is received in the second response message, a call set-up message is sent comprising an indication of the second service. h) If an indication that the requested service is not permitted for the called party is received in both response messages, the call is released.
[0035] In the cases d), e), f), g), and h), the indication that it is a further request can be omitted in the further routing information request message. In case h) the method continues with step 208 a , wherein a call release message is sent by the gateway mobile services switching centre. In the cases a) to g), the method continues in step 208 by sending a call set-up request according to the result of the analysing of the at least one response message.
[0036] In an embodiment of the invention, the step 205 is performed repeatedly until one message is sent for each service indication received in the call set-up request message received in step 201 .
[0037] In a further embodiment of the invention, the gateway mobile services switching centre detects that no indication that the home location register is capable of handling the indication that a further request message is received in the first response message. In this case no further request message is sent and a call set-up request comprising an indication of the first service is sent to the corresponding call control node.
[0038] FIG. 3 depicts the invented method as executed in a database for storing subscriber data. In the following said database will be called home location register to make it easier for a person skilled in the art to read the description but not to limit the scope of the invention.
[0039] In a first step 300 the method is started. In a next step 301 the home location register receives a routing information request comprising an identification of a called party, an indication of a service and an indication that a further request message will be sent. The home location register checks in a next step 302 the subscriber data of the called party and determines in a next step 303 that the requested service is permitted. In a following step 304 the home location register fetches a number for the further setting up of the connection towards the called party. This number can be for example a mobile station roaming number that is fetched from a mobile services switching centre or a forwarded to number for the called party fetched from a storage.
[0040] In a next step the home location register prepares a response message related to the result of the check of step 302 . The message comprises the number fetched in step 304 and an indication that the database is adapted to process the indication that at least one further routing information request will be sent. The home location register sends the response message in a next step 306 .
[0041] The figure comprises a first loop indicator LI 1 between the steps 306 and 307 and a second loop indicator LI 2 between steps 310 and 311 to illustrate that in an embodiment of the invention the steps 307 , 308 , 309 , and 310 are performed once for each further routing information request that is received.
[0042] In a next step 307 the home location register receives the further routing information request. In a next step 308 the home location register checks subscriber data of the called party. It prepares a response message in a next step 309 related to the result of the check of the subscriber data, and sends it in a next step 310 . The method ends in a step 311 .
[0043] FIG. 4 depicts a call control node CCN 1 according to the invention, comprising a message generation unit MGU 1 for generating a first routing information request message with an identification of a first service, an identification of a called party and an indicator that at least one further routing request message will be sent and for generating at least one further routing request message comprising an indication of a second service. The call control node CCN 1 further comprises an input output unit IOU 1 for sending and receiving messages and a processing unit for controlling and coordinating the units of the call control node and for analysing messages. The processing unit it also arranged to process a call set-up request message comprising an indication of two services in a way that it sends a first and a further routing information request message and to handle a call appropriately to a result of an analysis of the received response messages. For example by sending a call set-up request message or a call release message as described by means of FIG. 3 .
[0044] FIG. 5 depicts a database for storing subscriber data comprising a processing unit PU 2 arranged to process an indication received in a routing information request message, indicating that at least one further routing request message will be sent, wherein the processing is performed in a way that a mobile station roaming number is fetched and sent only in response to a first routing information request message for a connection and that an indication is returned in said response, indicating that the database is adapted to handle the received indicator.
[0045] It is an object of the invention to provide a software adapted to control a call control node in a way that it executes a method according to claim 1 or 2 .
[0046] It is another object of the invention to provide a software adapted to control a database node in a way that it executes a method according to claim 3 or 4 . | The invention relates to methods and devices that enable to request more than one service during call set-up. To this end a new indicator is introduced into a request message sent to a database storing subscriber data, for indicating that at least one further request message is sent and a response indicator that a database is adapted to handle said indicator. Furthermore a set of rules is defined how different responses from the database are processed to enable said request. | 7 |
FIELD OF INVENTION
This invention pertains to the field of fishing lures or baits.
BACKGROUND OF THE INVENTION
Man has used fishing as a vocation and as a means for getting food from the very beginnings of time. Artificial lures, bait fishing, spinning, casting, etc. have grown into popular sports today. When one goes trolling and utilizes lures or baits, it has been found that lures that will reflect light have a definite influence on one's ability to catch fish. On the other hand, placing an attractor on the line in addition to a lure adds weight and resistance to the line being pulled by the fish and as such makes it more difficult for the fisherman to catch the fish, as the fish is unable to pull the added weight with him after the strike.
There is indeed a need, therefore, for as improved attractor blade that will both reflect the light and will permit the fish to pull directly on the line, which pull will be felt at the tip of the pole, thereby advising the fisherman of a strike.
It is an object of this invention to provide an attractor blade which exhibits a new and novel action as it moves through the water.
It is another object of this invention to provide an attractor blade that allows the fish to pull directly to the fishing pole tip.
It is a further object of the invention to provide a fish attractor that can be utilized at any speed from very slow of one-half (1/2) mph to very fast, namely five (5) miles per hour.
It is a further object to provide a fish attractor that moves through the water with little resistance.
Yet another object is to provide a fish attractor that is capable of rotation around the fishing line to reflect the sun's rays down into the water.
These and other objects of the present invention will become apparent and will in part be obvious to those of skill within the fishing art.
SUMMARY OF THE INVENTION
A fish attractor is disclosed having an elongated main body portion capable of rotation around the axis on an elongated, tubular member upon which it is mounted. A hollow rudder attachment is disposed at one end, namely the front or forward end, of the attractor in order to provide stability in the water. The attractor is configured such that as it moves through the water at any speed, it will rotate and since it is preferably provided with a reflective surface, the sun rays will be reflected down into the water thus hopefully attracting fish.
KNOWN PRIOR ART
Applicant is aware of the following references as a result of a search of the prior art:
U.S. Pat. No. 0,167,784: Pierce
U.S. Pat. No. 0,295,350: Chapman
U.S. Pat. No. 0,613,519: Junod
U.S. Pat. No. 0,967,660: Pederson
U.S. Pat. No. 1,062,980: Lewis
U.S. Pat. No. 1,678,448: Shannon
U.S. Pat. No. 2,086,008: Turner
U.S. Pat. No. 2,518,081: Lane
U.S. Pat. No. 2,940,204: Mehnert
U.S. Pat. No. 3,789,536: Parmeson
U.S. Pat. No. 4,134,224: Clark
U.S. Pat. No. 4,139,962: Gardyszewski
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an elevational view of the instant device with the main body rotated to a vertical disposition.
FIG. 2 is a bottom plan view.
FIG. 3 is a front elevational view thereof.
FIG. 4 is a view similar to FIG. 1 but illustrating a second embodiment.
FIG. 5 is a front elevational view of a portion of the embodiment of FIG. 4.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Attractor blade 10 includes a main body portion 11 which comprises a pair of flat planar members 31 disposed on opposite sides of the hollow tube 14 which will be described in detail below. Planar panel member which consists of two mirror image interconnected segments commences at its rear with a first surface 21' normal to the elongation of said hollow tube 14. Member 31 diverges outwardly from the ends of surface 21' to a point 35, namely surface 34, then parallel forwardly in a straight surface 36 to point 37. The member 31 extends inwardly arcuately along surface 38 to a point 39 spaced from tube 14. The opposite side of member 31 is similar in configuration. A chamfer or diverging rearwardly surface commences at point 39 to a location spaced slightly from the tube. This rearwardly directed surface is designated as 41. At the basis of each 41's termination a tab 13 having a bore therein sized to receive the hollow tube 14 is disposed preferably integrally and about normal to said tubes.
Disposed along each surface 34 are a pair of fins 12A and 12B generally triangular in configuration. One of said fins is disposed upwardly, the other downwardly along surface 34. Preferably the fins are formed by folding planar member 31 so as to be integral, though they could be separately attached by conventional means. These fins are called turning fins since they rotate the body portion 11 in the water.
Planar member 31 also includes a central elongated axial slot 43, through which passes tube 14. Tube 14 is retained by a second tab 21 having a bore therein which second tab 21 is 180° oppositely directed from tab 13 but aligned with it and which 21 is about normal to the tube and disposed along rear first surface 21. Since the tabs are disposed normal to said tube 14, such that the tube 14 can pass through each of same and the elongated slot 43, the planar member can rotate around the tube due to the actions of the fins.
It is further seen that while the two tabs 13 and 21 are not quite normal to the tube, in order to avoid binding on rotation, the planar member 31 is disposed at end above and at one end below the hollow tube 14. See FIG. 2.
The elongated tube 14 is sized to fit through the circular tabs 13 and 21 each of which encircle the tube. Said tube further includes a pair of spacing beads at each end of said tube, said tube generally being of plastic or glass, which beads are held on said tube by the flared tube ends 17 and 19, 17 being the forwardly positioned end. At least one and preferably a pair of the spacer beads are disposed on said tube behind the main body portion 11 to the front of the punched tab 13. One of said beads is disposed between points 38 and 40 to prevent the main body portion from moving frontwardly along the length of the tube. Adequate space is provided between the bead and the angularly disposed leading surface 41 of the main body portion to permit rotation about said tube 14. Such beads are fixedly secured as by being pressed on or glued on by an adhesive. A forwardly disposed rudder 15 is downwardly disposed along said tube and is disposed between the most forward spacer bead and the intermediate spacer bead(s) in front of the main body portion 11. Said rudder is either secured along the outer edge of said tube or said tube may be grooved to receive said rudder. The rudder may be made of plastic or metal. If metal similar to the tube is employed, obviously spot welding as well as an adhesive may be employed to secure the rudder to the tube.
In the version shown in FIG. 1, an elongated space has been cut into each of the sections 31 in order to have minimum area in contact with the elongated tube to ensure easy rotation about the horizontal axis.
Note also that in FIG. 1 the two parallelogram shaped areas 45 represent typical zones that can be overcoated with prismatic material to reflect the sun.
It is seen that the attractor blade of this invention can be pulled through the water are variable speeds with little or no resistance. During such time as the blade is moving, the currents act as a fluid thereby causing the device to rotate as it moves along during the trolling period. Optionally, reflective zones such as those designated 45 and shown in FIG. 1 may be placed on opposite sides of the sections 31 in order to reflect the light during rotation. Optionally the two body sections may be made of a reflective metal such as aluminum, chrome plated steel, polished brass or anodized aluminum. These moving sun rays help attract fish to the line.
It is seen that the attractor blade of this invention is so constructed that the fishing line extends through the central tube forming part of the attractor blade. Thus the fish, when he strikes or bites, is free to pull the line without moving the attractor blade relative to its location at the point of strike in the water. Thus any pull on the line by the fish will be readily recognized by a bending of the tip of the fishing pole thereby signifying a strike to the fisherman.
The device of the instant invention may be made in several sizes from small for trout to large for salmon.
Other reflective and polished portions such as the fins may be of materials such as brass, chrome, stainless steel, lenticular plastic and prismatic plastic.
In the instant construction, it has been noted that there is a cut out elongated section, previously referred to as 43. This cut out permits water to flow through the device and thereby minimize drag.
Should one desire to speed up or slow down the rotation of the device about the central tube, a mere changing of the angle of the fins disposed along leading edges 12A and B will speed up or slow down the device. The greater the angle, up to 45°, the faster the rotation through the water.
In a modified version of the instant device, as seen in FIGS. 4 and 5, the rearmost spacer bead is replaced by a spoked wheel configured sonic disc. The disc 50 of a cross section diameter relative to the sizing of the balance of the device can vary from about one-half (1/2) inch to one and one-half (11/2) inches. The tubular member is inserted in the hub opening 51 prior to the flaring of the tube ends.
Disc 50 also includes a plurality of spokes 52 as well as the outer wheel 53.
In view of the close proximity of the main body portion 11 to disc 50 as the body portion rotates in the water the end tips thereof 54 will impinge upon the disc causing a vibratory sound. The impingement of tips 54 is insufficient to prevent rotation. It is more in the nature of a momentary snag during the rotational process. Disc 50 should preferably be made of metal.
In this embodiment, it may be beneficial to employ a larger rudder to prevent the tube from rotating on the fishing line than is employed in the standard version, i.e., the first embodiment. This is shown in FIG. 4.
Since the remainder of this embodiment is the same as discussed with respect to FIGS. 1-3, such discussion need not be repeated.
Obviously, it is recognized that the attractor blade of this invention can be used with any kind of fishing line just so that the line can be fed easily and speedily through the central tube.
In order to utilize the instant device, the fisherman merely slides the fishing line through the hollow, elongated tube through the front flare and then ties a large swivel to the end of the fishing line at that rear point. This secures the attractor blade on the line but allows the blade to slide free on the line. Lure or bait is then attached in the conventional manner to the swivel. Any type of hook or lure may be employed as may be desired.
It is seen that the instant device may be made of plastic or metal and that the surface can be left plain, made textured as with a striated design for example, or covered with a prismatic shining metal overlayer that will readily capture the sun's rays. The device can be made in all sizes suitable for the attraction of variously sized fish.
Obviously another receiving means such as a return washer can be employed to maintain the various components upon the hollow tube, in place of flared ends.
Since certain changes may be made in the above apparatus without departing from the scope of the invention herein involved, it is intended that all matter contained in the above description and shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense. | A fish attractor blade adapted to remain substantially stationary within the water after the fish strikes or grabs the hook and "runs" with the line through the water. | 0 |
CROSS REFERENCES TO RELATED APPLICATIONS
The present application is a divisional of and claims priority under 35 U.S.C. § 120 to U.S. patent application Ser. No. 11/005,246, entitled Proximity Sensor Nozzle Shroud with Flow Curtain, filed on Dec. 7, 2004, which issued as U.S. Pat. No. 7,017,390 on Mar. 28, 2006, which is hereby expressly incorporated by reference herein in its entirety.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to lithography, and more particularly, to immersion lithography proximity gauges.
2. Background of Invention
Many automated manufacturing processes require the sensing of the distance between a manufacturing tool and the product or material surface being worked. In some situations, such as semiconductor lithography, the distance must be measured with accuracy approaching a nanometer.
The challenges associated with creating a proximity sensor of such accuracy are significant, particularly in the context of photolithography systems. In the photolithography context, in addition to being non-intrusive and having the ability to precisely detect very small distances, the proximity sensor can not introduce contaminants or come in contact with the work surface, typically a semiconductor wafer. Occurrence of either situation may significantly degrade or ruin the semiconductor quality.
Different types of proximity sensors are available to measure very small distances. Examples of proximity sensors include capacitance and optical gauges. These proximity sensors have serious shortcomings when used in photolithography systems because physical properties of materials deposited on wafers may impact the precision of these devices. For example, capacitance gauges, being dependent on the concentration of electric charges, can yield spurious proximity readings in locations where one type of material (e.g., metal) is concentrated. Another class of problems occurs when exotic wafers made of non-conductive and/or photosensitive materials, such as Gallium Arsenide (GaAs) and Indium Phosphide (InP), are used. In these cases, capacitance and optical gauges may provide spurious results.
Commonly owned U.S. patent application, Ser. No. 10/322,768, entitled High Resolution Gas Gauge Proximity Sensor, filed Dec. 19, 2002 by Gajdeczko et al., (“'768 patent application”) describes a high precision gas gauge proximity sensor that overcomes some of the precision limitations of earlier air gauge proximity sensors. The 768 patent application, which is incorporated herein in its entirety, describes a gas gauge proximity sensor that provides a high degree of accuracy. Similarly, commonly owned U.S. patent application, Ser. No. 10/683,271, entitled Liquid Flow Proximity Sensor for Use in Immersion Lithography, filed Oct. 14, 2003, by Violette, Kevin, (“'271 patent application”) describes a high precision immersion lithography proximity sensor that provides a high degree of precision in an immersion lithography application. The '768 patent application issued as U.S. Pat. No. 7,010,958 on Mar. 14, 2006. The '271 patent application issued as U.S. Pat. No. 7,021,119 on Apr. 4, 2006.
Co-pending, commonly owned U.S. patent application, Ser. No. 10/322,768, entitled High Resolution Gas Gauge Proximity Sensor, filed Dec. 19, 2002 by Gajdeczko et al., (“'768 patent application”) describes a high precision gas gauge proximity sensor that overcomes some of the precision limitations of earlier air gauge proximity sensors. The 768 patent application, which is incorporated herein in its entirety, describes a gas gauge proximity sensor that provides a high degree of accuracy. Similarly, co-pending, commonly owned U.S. patent application, Ser. No. 10/683,271, entitled Liquid Flow Proximity Sensor for Use in Immersion Lithography, filed Oct. 14, 2003, by Violette, Kevin, (“'271 patent application”) describe a high precision immersion lithography proximity sensor that provides a high degree of precision in an immersion lithography application.
While the sensors disclosed in the '768 and '271 patent applications provide a high degree of precision, the precision can be impacted by cross flows of gas or liquid that intersect the stream of gas or liquid that is being emitted from a measurement channel of the proximity sensor. Specifically, purging gases, for example, can exhibit local cross winds with velocities of the order of a few meters per second. Cross-winds or cross-flows will cause gauge instability and drift, introducing non-calibratable errors within proximity sensors.
What is needed is an apparatus to neutralize these cross-flows, and in the case of immersion lithography, cross currents, to improve the accuracy of proximity sensors.
SUMMARY OF THE INVENTION
The present invention is directed to an immersion lithography proximity sensor having a nozzle shroud with a flow curtain. The immersion lithography proximity sensor includes a shroud that affixes to the nozzle. A plenum is located inside the shroud that holds a shroud liquid, which is fed into the plenum through one or more intake holes. The shroud liquid is emitted out through a series of openings, such as holes or slots, along a bottom surface of the shroud in a direction away from the nozzle. The shroud liquid that is emitted forms a curtain around the nozzle to prevent cross currents from impacting the flow of liquid out of the nozzle.
Further embodiments, features, and advantages of the invention, as well as the structure and operation of the various embodiments of the invention are described in detail below with reference to accompanying drawings.
BRIEF DESCRIPTION OF THE FIGURES
The invention is described with reference to the accompanying drawings. In the drawings, like reference numbers indicate identical or functionally similar elements. The drawing in which an element first appears is indicated by the left-most digit in the corresponding reference number.
FIG. 1 is a schematic diagram showing the functional components of a proximity sensor.
FIG. 2 is a diagram of a proximity sensor nozzle having a shroud with a flow curtain, according to an embodiment of the invention.
FIG. 3 is a diagram of a bottom view of a proximity sensor nozzle having a shroud that produces a flow curtain, according to an embodiment of the invention.
FIG. 4 is a diagram of a cross sectional view of a proximity sensor nozzle having a shroud that produces a flow curtain, according to an embodiment of the invention.
DETAILED DESCRIPTION OF THE INVENTION
While the present invention is described herein with reference to illustrative embodiments for particular applications, it should be understood that the invention is not limited thereto. Those skilled in the art with access to the teachings provided herein will recognize additional modifications, applications, and embodiments within the scope thereof and additional fields in which the invention would be of significant utility
FIG. 1 illustrates gas gauge proximity sensor 100 , according to an embodiment of the present invention. Gas gauge proximity sensor 100 includes mass flow controller 106 , central channel 112 , measurement channel 116 , reference channel 118 , measurement channel restrictor 120 , reference channel restrictor 122 , measurement probe 128 , reference probe 130 , bridge channel 136 and mass flow sensor 138 . Gas supply 102 injects gas at a desired pressure into gas gauge proximity sensor 100 .
Central channel 112 connects gas supply 102 to mass flow controller 106 and then terminates at junction 114 . Mass flow controller 106 maintains a constant flow rate within gas gauge proximity sensor 100 . Gas is forced out from mass flow controller 106 through a porous snubber 110 , with an accumulator 108 affixed to channel 112 . Snubber 110 reduces gas turbulence introduced by the gas supply 102 , and its use is optional. Upon exiting snubber 110 , gas travels through central channel 112 to junction 114 . Central channel 112 terminates at junction 114 and divides into measurement channel 116 and reference channel 118 . Mass flow controller 106 injects gas at a sufficiently low rate to provide laminar and incompressible fluid flow throughout the system to minimize the production of undesired pneumatic noise. Likewise, the system geometry can be appropriately sized to maintain the laminar flow characteristics established by mass flow controller 106 .
Bridge channel 136 is coupled between measurement channel 116 and reference channel 118 . Bridge channel 136 connects to measurement channel 116 at junction 124 . Bridge channel 136 connects to reference channel 118 at junction 126 . In one example, the distance between junction 114 and junction 124 and the distance between junction 114 and junction 126 are equal.
All channels within gas gauge proximity sensor 100 permit gas to flow through them. Channels 112 , 116 , 118 , and 136 can be made up of conduits (tubes, pipes, etc.) or any other type of structure that can contain and guide gas flow through sensor 100 . The channels do not have sharp bends, irregularities or unnecessary obstructions that may introduce pneumatic noise, for example, by producing local turbulence or flow instability. The overall lengths of measurement channel 116 and reference channel 118 can be equal or in other examples can be unequal.
Reference channel 118 terminates into reference nozzle 130 . Likewise, measurement channel 116 terminates into measurement nozzle 128 . Reference nozzle 130 is positioned above reference surface 134 . Measurement nozzle 128 is positioned above measurement surface 132 . In the context of photolithography, measurement surface 132 is often a semiconductor wafer or stage supporting a wafer. Reference surface 134 can be a flat metal plate, but is not limited to this example. Gas injected by gas supply 102 is emitted from each of the nozzles 128 , 130 and impinges upon measurement surface 132 and reference surface 134 . As stated above, the distance between a nozzle and a corresponding measurement or reference surface is referred to as a standoff.
Measurement channel restrictor 120 and reference channel restrictor 122 serve to reduce turbulence within the channels and act as a resistive element. In other embodiments, orifices can be used. Although orifices will not reduce turbulence.
In one embodiment, reference nozzle 130 is positioned above a fixed reference surface 134 with a known reference standoff 142 . Measurement nozzle 128 is positioned above measurement surface 132 with an unknown measurement standoff 140 . The known reference standoff 142 is set to a desired constant value representing an optimum standoff. With such an arrangement, the backpressure upstream of the measurement nozzle 128 is a function of the unknown measurement standoff 140 ; and the backpressure upstream of the reference nozzle 130 is a function of the known reference standoff 142 . If standoffs 140 and 142 are equal, the configuration is symmetrical and the bridge is balanced. Consequently, there is no gas flow through bridging channel 136 . On the other hand, when the measurement standoff 140 and reference standoff 142 are different, the resulting pressure difference between the measurement channel 116 and the reference channel 118 induces a flow of gas through mass flow sensor 138 .
Mass flow sensor 138 is located along bridge channel 136 , preferably at a central point. Mass flow sensor 136 senses gas flows induced by pressure differences between measurement channel 116 and reference channel 118 . These pressure differences occur as a result of changes in the vertical positioning of measurement surface 132 . For a symmetric bridge, when measurement standoff 140 and reference standoff 142 are equal, the standoff is the same for both of the nozzles 128 , 130 compared to surfaces 132 , 134 . Mass flow sensor 138 will detect no mass flow, since there will be no pressure difference between the measurement and reference channels. Differences between measurement standoff 140 and reference standoff 142 will lead to different pressures in measurement channel 116 and reference channel 118 . Proper offsets can be introduced for an asymmetric arrangement.
Mass flow sensor 138 senses gas flow induced by a pressure difference or imbalance. A pressure difference causes a gas flow, the rate of which is a unique function of the measurement standoff 140 . In other words, assuming a constant flow rate into gas gauge 100 , the difference between gas pressures in the measurement channel 116 and the reference channel 118 is a function of the difference between the magnitudes of standoffs 140 and 142 . If reference standoff 142 is set to a known standoff, the difference between gas pressures in the measurement channel 116 and the reference channel 118 is a function of the size of measurement standoff 140 (that is, the unknown standoff in the z direction between measurement surface 132 and measurement nozzle 128 ).
Mass flow sensor 138 detects gas flow in either direction through bridge channel 136 . Because of the bridge configuration, gas flow occurs through bridge channel 136 only when pressure differences between channels 116 , 118 occur. When a pressure imbalance exists, mass flow sensor 138 detects a resulting gas flow, and can initiate an appropriate control function. Mass flow sensor 138 can provide an indication of a sensed flow through a visual display or audio indication. Alternatively, in place of a mass flow sensor, a differential pressure sensor may be used. The differential pressure sensor measures the difference in pressure between the two channels, which is a function of the difference between the measurement and reference standoffs.
Proximity sensor 100 is provided as one example of a device with a nozzle that can benefit from the present invention. The invention is not intended to be limited to use with only proximity sensor 100 . Rather the invention can be used with other types of proximity sensors, as well as other nozzles that emit gases or liquids in which the flow of the emitted gas or liquid needs to be protected from cross winds or cross currents.
FIG. 2 is a diagram of a vertical cross section of proximity sensor measurement nozzle 128 having shroud 210 with a flow curtain, according to an embodiment of the invention. Measurement nozzle 128 includes channel 229 and opening 228 . As discussed above, gas will flow through channel 229 and exit measurement nozzle 128 through opening 228 . The gas impinges on measurement surface 132 , and based on the amount of backpressure within proximity sensor 100 a measurement of the standoff 140 can be estimated.
When cross-winds flow through the area around standoff 140 , the cross-winds will impact the amount of backpressure and degrade the precision of proximity sensor 100 . Typically, cross-winds only impact measurement standoffs, as reference standoffs are often sheltered by enclosed area that eliminates cross-winds. Thus, the invention focuses on using a shroud on a measurement nozzle. However, the invention is not limited to this case. The shroud can be used on any type of nozzle in which protection against cross-winds or cross currents of fluids need to be reduced.
Measurement nozzle 128 is surrounded by shroud 210 . Shroud 210 is made of materials that are suitable for a lithography environment, or other environment in which the shroud is being used. The specific types of acceptable materials will be known to individuals skilled in the relevant arts based on the teachings herein.
In embodiments shroud 210 can be affixed to measurement nozzle 128 by use of a fastener, glue, epoxy or the like. In an embodiment shroud 210 substantially circumscribes measurement nozzle 128 . In another embodiment, measurement nozzle 128 and shroud 210 can be machined as a single structure. In a further embodiment, shroud 210 can be snapped around measurement nozzle 128 and held in place by a small latch on shroud 210 .
Shroud 210 includes plenum 220 that serves as a reservoir to hold a shroud gas. In the case of an immersion lithography proximity sensor, plenum 220 holds a shroud liquid. Shroud 230 includes an intake hole 230 , which allows shroud gas to be emitted into plenum 220 . A series of holes, such as holes 242 and 244 exist along a lower surface of shroud 210 , such that the holes emit the shroud gas in a direction away from measurement nozzle 120 to form a gas curtain. In an alternate embodiment, slots can be used in place of the holes. Parameters, such as the number of holes, angle of the holes, diameter of the holes and velocity of gas being emitted are adjusted, such that an integrally continuous gas curtain is created around the lower portion of shroud 210 .
The holes project cones of shroud gas having an arrival velocity at point 264 , such that the horizontal components of the shroud gas flow arrival velocity is equal to or greater than the horizontal components of cross winds. Arrival point 264 represents the intersection of the centerline of a shroud gas cone, such as shroud gas cone 252 and 254 , and measurement surface 132 . FIG. 2 illustrates shroud gas cone 254 , which is emitted from hole 244 and shroud gas cone 252 , which is emitted from hole 242 .
FIG. 3 is a diagram of a bottom view of measurement nozzle 128 and shroud 210 . Nozzle opening 228 appears at the center of the diagram, surrounded by measurement nozzle 128 . Interface 222 represents the interface between measurement nozzle 128 and shroud 210 . In this example, shroud 210 includes eight holes, such as holes 242 and 244 .
FIG. 4 is a diagram of a cross sectional view of shroud 210 and measurement nozzle 128 . The cross section illustrates that plenum 220 fully encircles shroud 210 . In other embodiments, multiple plenums can be used within shroud 210 .
While the discussion above has focused primarily on the use of shroud 210 with a gas gauge proximity sensor, shroud 210 can also be used with an immersion lithography proximity sensor, such as, for example, the one disclosed in the '271 patent application. Additionally, the invention can be used with other types of nozzles that emit a gas or liquid in which the flow of the emitted gas or liquid needs to be protected from cross winds or cross currents.
When used in immersion lithography, plenum 220 would contain a shroud liquid. The shroud liquid would be emitted through holes 242 and 244 to form a liquid curtain that shields the flow of liquid from a measurement nozzle from cross-currents of liquid that may be occurring that would degrade performance. The specific location of holes, number of holes, angles of the holes, velocity of shroud liquid would be a function of a particular design application, as can be determined by individuals skilled in the relevant arts, based on the teachings herein.
CONCLUSION
Exemplary embodiments of the present invention have been presented. The invention is not limited to these examples. These examples are presented herein for purposes of illustration, and not limitation. Alternatives (including equivalents, extensions, variations, deviations, etc., of those described herein) will be apparent to persons skilled in the relevant art(s) based on the teachings contained herein. Such alternatives fall within the scope and spirit of the invention. | The present invention is directed to an immersion lithography proximity sensor having a nozzle shroud with a flow curtain. The immersion lithography proximity sensor includes a shroud that affixes to the nozzle. A plenum is located inside the shroud that holds a shroud liquid, which is fed into the plenum through one or more intake holes. The shroud liquid is emitted out through a series of openings, such as holes or slots, along a bottom surface of the shroud in a direction away from the nozzle. The shroud liquid that is emitted forms a curtain around the nozzle to prevent cross currents from impacting the flow of liquid out of the nozzle. | 6 |
RELATED APPLICATIONS
This application is a divisional of application Ser. No. 10/045,122, filed Nov. 9, 2001, now U.S. Pat. No. 7,286,878 which is incorporated herein by reference in its entirety.
FIELD OF THE INVENTION
The present invention relates to the field of implantable systems for stimulating electrically excitable tissue within a patient. More specifically, the present invention provides a system that includes an extension unit that connects an implantable pulse generator to an implantable lead or electrode array.
BACKGROUND OF THE INVENTION
Electrical stimulation of the spinal cord and deep brain has been used for pain relief and to control movement disorders. Electrical leads having many electrodes are implanted in the body such that one or more cathodes and one or more anodes are in optimal locations to produce benefits or to minimize undesirable side effects. FIG. 1 shows a typical implantable electrical stimulation system. An implantable pulse generator 10 generates the electrical signals that will provide the stimulation. A cable 20 connects the implantable pulse generator 10 to a lead 30 . Lead 30 contains individual electrodes 31 - 40 . Cable 20 contains ten separate conductors connecting the implantable pulse generator to each of the electrodes 31 - 40 . Implantable electrical stimulation systems are described in co-pending patent application Ser. No. 09/024,162 filed Feb. 17, 1998 and co-pending patent application Ser. No. 08/627,576 filed Apr. 4, 1996. The entire disclosures of both co-pending applications are incorporated herein by reference.
It would be desirable to use a lead with a large number of electrodes, such as sixteen or more, for some therapies. The polarity of each electrode could be assigned and the optimal combinations of cathodes and anodes could be selected for each patient. Another advantage to having several electrodes is that it allows for adjusting the stimulation after the components have been implanted. In particular, an implanted spinal cord stimulation lead can shift up to 0.5 cm or more after being inserted in the body. Ideally, the lead should contain enough electrodes so that some electrodes can be switched off and others switch on after the shift has taken place to avoid the patient undergoing another surgical procedure. It may also be desirable to change the location of the stimulation after the lead has been implanted.
The use of a large number of electrodes on a lead has been limited, in part, because of the limitations imposed by the conductors that connect the implantable pulse generator to the lead. Typical implantable electrical stimulation systems pass up to 20 milliamperes or more of current through each conductor, involving current densities of 10 microcoulombs per square centimeter per phase or more. As a result, each electrode is connected to a sizable conductor in order to minimize energy losses due to impedance and to provide adequate strength to connect the wire to a power supply without substantial risk of breakage. The size of the conductors has made it impractical to connect a large number of conductors between the implantable pulse generator and the electrodes on the lead. Furthermore, it is difficult to obtain the required reliability when using a large number of conductors.
One proposed system places a semiconductor device on the lead to perform a multiplexing operation to minimize the number of conductors connecting the implantable pulse generator to the electrodes. The semiconductor increases the size of the lead and may require significant changes to the standard procedure currently used to implant leads as well as the manufacturing procedures.
Therefore, there exists a need in the art for an implantable electrical stimulation system that includes a large number of electrodes without increasing the size of the lead and that minimizes the number of conductors connecting the implantable pulse generator to the electrodes.
SUMMARY OF THE INVENTION
The present invention provides an implantable electrical stimulation system and method that includes a large number of electrodes with a reduced number of conductors connecting the implantable pulse generator to the electrodes. Minimizing the number of conductors for a given number of electrodes increases reliability and the number of electrodes that can be used.
In one embodiment, the advantages of the present invention are realized by an apparatus for selectively interacting with electrically excitable tissue of a patient. The apparatus includes an implantable pulse generator having a number of output sources that transmit electrical signals and an implantable electrode array having a number of electrodes, wherein the number of electrodes is greater than the number of output sources. An extension unit is coupled between the implantable pulse generator and the implantable electrode array and is configured to electrically connect the output sources to a portion of the electrodes.
The implantable electrode array may include at least one biomedical sensor. Furthermore, the electrodes may be arranged in a line or in a multi-dimensional array.
The advantages of the present invention may also be realized with an extension unit that electrically connects an implantable pulse generator having a number of output sources that transmit pulse signals to an implantable electrode array having a number of electrodes, wherein the number of electrodes is greater than the number of output sources. The extension unit includes an array of programmable switches, each switch being connected between one output lead and at least a portion of the electrodes. The extension unit may also include a programming logic unit, coupled to the array of programmable switches, that receives programming signals and produces signals for configuring the programmable switches.
In yet another embodiment of the invention a method of selectively providing electrical therapeutic treatment to a patient using an electrode array is provided. The method includes the steps of implanting an electrode array having a number of electrodes near electrically excitable tissue of a patient and implanting a pulse generator having a number of output electrode arrays in the patient, the number of output sources being less than the number of electrodes. An extension unit is also implanted between the electrode array and the pulse generator. The extension unit electrically connects the output sources to a portion of the electrodes. After the devices are implanted, it is determined which electrodes are physically positioned to provide optimal therapeutic treatment and the extension unit is configured to electrically couple the output sources to the electrodes identified in the determining step. Alternatively, the method may include implanting an array having a number of biomedical sensors in a patient and implanting a diagnostic device.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention is illustrated by way of example and not limited in the accompanying figures in which like reference numerals indicate similar elements and in which:
FIG. 1 shows a related art implantable electrical stimulation system.
FIG. 2 is a schematic diagram of an implantable electrical stimulation system in accordance with a preferred embodiment of the invention.
FIG. 3 is a schematic diagram of an extension unit in accordance with a preferred embodiment of the invention.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
FIG. 2 shows an implantable electrical stimulation system in accordance with an embodiment of the invention. An implantable pulse generator (IPG) 220 generates the stimulation signals. The structure and operation of IPGs is known to those skilled in the art. IPG 220 , which includes housing 220 a , is connected to extension unit 226 , which includes housing 226 a , with three electrical conductors 222 - 224 . Extension unit 226 is connected to implantable electrode array 228 with six conductors 230 - 235 . Extension unit 226 receives three electrical signals on conductors 222 - 224 and transmits those signals to three of conductors 230 - 235 . FIG. 2 shows an embodiment in which extension unit 226 is located closer to implantable electrode array 228 than to IPG 220 to minimize the overall length of the conductors connecting IPG 220 to implantable electrode array 228 . Extension unit 226 will be described in detail with reference to FIG. 3 .
Electrode array 228 can be implanted at a site within a patient adjacent the tissue to be stimulated. Electrode array 228 has six electrodes 238 - 243 arranged in a straight line for illustration purposes only. Each of the electrodes 238 - 243 are electrically insulated from the other electrodes and can have an area of about 1-6 mm 2 . In operation, several neighboring electrodes can be connected in parallel to have a combined surface area of 6-24 mm 2 . Of course other sizes and configurations can be used to meet the patient's treatment needs. Electrodes 238 - 243 are electrically conductive and are preferably made from a metal like platinum or iridium.
Electrode array 228 can have a variety of different shapes. For example, electrode array 228 and/or electrodes 238 - 243 may be planar or any other shape (e.g., round, oval, and rectangular). Electrodes 238 - 243 also may have three dimensional outer surface (e.g., cylindrical, spherical, semispherical or conical). Electrode array 228 may also have any number of electrodes, such as sixteen or more and may also include one or more biomedical sensors (not shown) in place of or in addition to electrodes 238 - 243 . A diagnostic device (not shown) may be connected to electrodes and/biomedical sensors through an extension unit that is similar to extension unit 226 . Examples of diagnostic devices include glucose sensors, circuits that measure voltage levels and devices that store information. In alternative embodiment (not shown), two or more electrode arrays can be connected to a single extension unit.
Extension unit 226 allows a physician or patient to select which electrodes 238 - 243 will receive stimulation pulses. Being able to select and activate electrodes from a large number of possible sites provided by the preferred embodiments is valuable in case any site becomes unusable due to mechanical/electrical problems, scar tissue, electrode array migration, etc. A near neighboring site might give almost as useful a result. Furthermore, one does not always know before implantation what is the best strategy for electrode array placement and electrode polarity. Extension unit 226 allows the choice to be made later, and with additional reprogramming at later dates, to give degrees of freedom in the active electrode positions. For example, it is sometimes useful to have three or more electrodes in a line (especially transverse to the spinal cord axis), so that two or three can be chosen at preferred medial/lateral positions. The present invention enables changes in effective stimulation area after implantation by programming only while minimizing the number of conductors that connect IPG 220 to electrode array 228 .
Extension unit 226 can also be used to allow the patient or physician to optimize the diagnostic function of implanted electrodes or biomedical sensors. A large number of electrodes and/or biomedical sensors can be implanted in the patient and the optimum ones can then be selected after implantation.
FIG. 3 illustrates a schematic diagram of an extension unit 226 in accordance with a preferred embodiment of the invention. Extension unit 226 includes input lines 302 - 304 that receive the input signals from the IPG 220 (shown in FIG. 2 ). Input lines 302 - 304 are connected to wave shaping circuits 306 - 308 . Wave shaping circuits 306 - 308 are electrically connected to switches 310 - 312 , which are connected to output lines 314 - 319 . Output lines 314 - 319 are connected to electrode array 228 (shown in FIG. 2 ). Extension unit 228 may also include a controller 320 for controlling the overall operation of the unit, a communication circuit 322 for communicating with external circuits, a master clock 324 and a battery 326 .
The operation of extension unit 226 will now be described. Wave shaping circuits 306 - 308 receive the input signals, which are generally pulses and reshapes the input signals, if necessary. Wave shaping may include changing the voltage level of the pulse or the frequency of the pulse. Wave shaping circuits 306 - 308 may be implemented with a variety of electrical components including potentiometers and integrated circuits. Controller 320 may receive clock signals from clock 324 and control one or more of the wave shaping circuits 306 - 308 to change the polarity, voltage level or frequency of the input signals.
The outputs of the wave shaping circuits 306 - 308 are transmitted to switches 310 - 312 . Switches 310 - 312 may be implemented with a variety of electrical switches, including semiconductor switches. In one preferred embodiment, switches 310 - 312 are micro-relay switches that retain their switching state after power has been removed. Battery 326 may provide power to the micro-relay switches. Switches 310 - 312 are electrically connected to output lines 314 - 319 .
Switches 310 - 312 can be configured to transmit the signals they receive to any three of output lines 314 - 319 . Switches 310 - 312 can be controlled by controller 320 , a source external to the body, communication circuit 322 or any combination of the three. Three input lines 302 , three switches 310 - 312 and six output lines 314 - 319 are shown for illustration purposes only. Extension unit 28 can be configured to interface with any number of input lines and output lines. In one embodiment of the invention, the number of switches corresponds to the number of input lines. In the same embodiment, each switch has a number of output ports that is equal to 1+the number of output lines−the number of switches. For example, if the extension unit interfaces with five input lines and fifty output lines, the extension unit would need five 1×46 switches. Alternatively, each of the switches may be configured to be connectable to fewer of the output lines.
There are a number of conventional technologies that can be used to communicate with extension unit 226 . Communication can be accomplished with needles, screwdrivers, telemetry or electromagnetic energy. In one embodiment of the invention, IPG 220 (shown in FIG. 2 ) can be used to program extension unit 226 . In particular, input lines 302 - 304 are connected to controller 320 . Controller 320 may include hardware or software to recognize programming signals and for programming wave shaping circuits 306 - 308 and/or switches 310 - 312 . Such programming signals can include predetermined programming state pulse sequences or pulses have predetermined characteristics such as pulse length followed by programming pulses having characteristics that are recognized by controller 320 . After receiving the programming signals, controller 320 can then adjust wave shaping circuits 306 - 308 and/or switches 310 - 312 .
In one embodiment of the invention, extension unit 226 can be used to increase the number of electrodes that receive pulse signals. Referring to FIG. 3 , wave shaping circuits 306 - 308 can double the voltage level and frequency of the received pulses. Switches 310 - 312 and then be controlled to route the signals to output lines 314 - 316 during a first clock period and to output lines 317 - 319 during a second clock period. Furthermore, the determination of which electrodes are anodes or cathodes can be chosen by the patient or through investigation by clinicians to maximize the desired effects of stimulation, e.g., maximize pain relief, minimize spasticity, stop seizures, cause contraction of muscles, etc., and also to minimize undesirable side effects. The flexibility provided by the ability to alter the shape and frequency of the input signals allows one to provide numerous types of output signals.
The invention is useful in connection with electrically excitable tissue that includes both neural tissue and muscle tissue. Neural tissue includes peripheral nerves, the spinal cord surface, the deep spinal cord, deep brain tissue and brain surface tissue. Muscle tissue includes skeletal (red) muscle, smooth (white) muscle, and cardiac muscle. Furthermore, the invention works especially well for red skeletal muscle, since stimulation on such a muscle can only activate the muscle fibers directly under the cathode. Action potentials do not spread from muscle fiber to fiber, as they do in smooth muscle or cardiac muscle. Hence, a broad array of cathodes is useful to recruit many fibers of a red muscle.
Advantageous uses for electrode array L1-L5 described in this specification include:
A) Over or in motor cortex or cerebellar cortex, where there are somatotopic maps of the body, and where fine control of the loci of excitation can help affect the movements or control of various body parts.
B) Over or in the sensory cortex, which also has a somatotopic map, so that paresthesia and/or motor effects can be adjusted to specific body parts.
C) In the thalamus, where there is a three-dimensional body map, and where there are lamina of cells that might best be activated (or partly activated) using many contacts and programming.
D) In deep tissue, where stimulation is advantageously achieved by cylindrical leads.
E) Transversely and over the cauda equina (nerves in the spinal canal descending from the tip of the cord) to enable great selectivity of stimulation.
F) In the cochlea, where there is insufficient space for many wires, but many channels are needed and where fine-tuning which sites along the cochlea get stimulated might lead to much better hearing.
G) Over branches of motor nerves or large nerves, to activate distinct fascicles.
H) In the retina, where if a patient has no light going to the back of the eye, the preferred embodiment could stimulate in neural patterns as if light were going there in focus and being perceived.
Another advantage of the invention is that allows physicians and patients to use IPGs and electrode arrays manufactured by different companies. The disclosed extension unit can be used for interfacing an IPG that was not designed to operate with a particular electrode array. One skilled in the art will appreciate that the extension unit can include additional circuits that are specifically designed to couple a particular extension unit to a particular electrode array.
While the present invention has been described in connection with the illustrated embodiments, it will be appreciated and understood that modifications can be made without departing from the true spirit and scope of the invention. | A method for selectively interacting with electrically excitable tissue of a patient is provided. In one configuration, an implantable pulse generator with a number of outputs and an array of electrodes with a number of electrodes being greater than the number of outputs may be implanted in a patient. An extension unit may be implanted between the implantable pulse generator and array. The extension unit acts to electrically couple the inputs of implantable pulse generator with the greater number of electrodes in the array so that the output sources are coupled to a portion of the electrodes. | 0 |
BACKGROUND—FIELD OF THE INVENTION
[0001] This invention relates to buildings located in areas exposed to flooding, for example due hurricane or other natural or man-made conditions, which can become uninhabitable or dangerous after the flooding has subsided. Past experience with flooding and hurricane disasters show that evacuation of inhabitants in advance of a threatening disaster may be prevented by traffic congestions, unusually fast onset of the flooding, broken dams, coincidence of heavy winds, faulty predictions, and/or delayed evacuation orders by authorities, or simply as a result of the inhabitants waiting too long with their move to a safer area. All these factors have been clearly demonstrated in connection with past flooding related to hurricanes and tsunamis. Other experience demonstrates that extraordinary conditions often result from natural disasters and have a tendency to last many weeks, sometimes months, thus the inhabitants of areas exposed to flooding as a result of hurricane or other natural or man-made conditions many times will have to wait long time periods before public utilities, such as drinking water, and electricity supply, and sewer system, are restored. In the interim, lack of a good source of food, drinking water, electricity, and other public utilities can lead to illness and loss of human life.
BACKGROUND—DESCRIPTION OF THE RELATED ART
[0002] Housing in areas exposed to flooding are commonly connected in a rigid manner to a foundation, and cannot be lifted by the rising floodwater. Furthermore, as they become flooded, not only are they adversely affected, stored resources required for human survival also become destroyed. Even permanently elevated buildings which provide escape to upper levels, and ultimately to the roof, are not self-contained and thereby do not provide a good opportunity for the survival of inhabitants beyond the time period of a few days. Lack of portable water, lack of electrical energy, and the rapid accumulation of sewage in the inhabitants' surroundings quickly weaken the resistance of surviving inhabitants against infections, exhaustion, and deterioration of health. No known self-contained floating house unit is known that has all of the features and advantages of the present invention.
SUMMARY OF THE INVENTION—OBJECTIVES AND ADVANTAGES
[0003] The primary objective of this invention is to provide a storm-proof self-contained floating housing unit that is able to withstand forces caused by the heavy winds and flooding experienced during hurricanes, tornadoes, earthquakes, fire, and other natural and man-made disasters. The key materials that make this building possible are a combination of aluminum and foam, which together give the building its strength and durability, as well as insulation, floatation and heat resistant. The housing unit structure consists of aluminum walls with foam pumped in between the aluminum walls throughout the whole building. The foundation of the structure consists of the same materials with air tubing inside which adds to the structure's buoyancy. The present invention housing unit is guided with vertical poles in its corners that allow it lift from the ground during flooding and remain above its concrete pad without drifting away. The base in the lower region of the building contains chambers and spaces for water, electrical energy, and sewer facility that are essential for habitation, and further has a low specific weight and density creating buoyancy exceeding the total weight of the building's structure and payload, ensuring that the floor of the building always remains above the rising floodwater. Payload is defined as the weight of all inhabitants, removable equipment, furniture, foodstuff and materials required for permanent habitation. Other features of the invention will be described in connection with the drawing.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE INVENTION
[0004] FIG. 2 is a side view of a building in the most preferred embodiment of the present invention showing the building positioned above a concrete slab on the ground, with several spacers separating a broken line representation of the building's bottom contour L 1 from the concrete slab at normal water table conditions designated by W 1 , with a hypothetical flood condition water level designated by W 2 being shown above W 1 , with the bottom contour of the building during the flood condition represented by the designation L 2 , several vertically-extending poles are also shown between the concrete slab and the elevated structure.
[0005] FIG. 3 is an enlarged view of a vertical post in the corner of the vertically-deployable structure in the most preferred embodiment of the present invention that is encircled and marked with the letter “B” in FIG. 1 .
[0006] FIG. 4 is an enlarged view of one of the rolling contact units for vertically-extending poles with rectangular cross-section that can used in the most preferred embodiment of the present invention to ensure smooth relative movement between the building structure and the poles.
[0007] FIG. 5 is an enlarged view of one of the rolling contact units for vertically-extending poles with rectangular cross-section that can used in the most preferred embodiment of the present invention to ensure smooth relative movement between the building structure and the poles.
[0008] FIG. 6 is an enlarged view of one of the rolling contact units for vertically-extending poles with circular cross-section that can used in the most preferred embodiment of the present invention to ensure smooth relative movement between the building structure and the poles.
[0009] FIG. 7 is an enlarged view of one of the rolling contact units for vertically-extending poles with circular cross-section that can used in the most preferred embodiment of the present invention to ensure smooth relative movement between the building structure and the poles.
DETAILED DESCRIPTION OF THE INVENTION
[0010] FIGS. 1 and 2 show a one possible layout of a present invention self-contained floating building in accordance with the description herein, respectively in horizontal projection and vertical cross-section. FIG. 2 shows the building in an elevated position as it would be viewed during flood conditions, with the flood condition water level, W 2 , being much higher than the normal water table, which is also identified in FIG. 2 by the alpha-numeric designation of W 1 .
[0011] The ground 1 shown in FIG. 2 is covered by concrete slab 2 having several supporting spacers 3 . In addition, FIG. 2 shows three poles 4 firmly inserted through concrete slab 2 and precisely positioned in spaced-apart array along the side of the present invention building facing an observer. In contrast, nine poles 4 are shown in FIG. 1 in spaced-apart array throughout the most preferred embodiment of the present invention self-contained floating building, three observed from each side and a centrally located post 4 in the middle. In FIG. 2 , line L 1 represents the bottom contour of the present invention building during normal conditions when it is resting on the spacers 3 above concrete slab 2 . When flooding raises the water level above ground 1 to elevation W 2 , the present invention floating building's bottom contour line moves to the elevated position marked with the alpha-numeric designation of L 2 . The lower region of the present invention building structure, its base 6 , provides all the necessary buoyancy to exceed the total weight of the building's structure and payload, ensuring that the floor of the building always remains above the rising floodwater. Although not shown in the illustrations, payload is defined as the weight of all inhabitants, removable equipment, furniture, foodstuff and materials required for permanent habitation. The shape of the lower region of the present invention building structure, also referred to herein as base 6 , may be similar to a barge as shown in FIG. 2 where the bottom of base 6 rises toward each of its perimeter edges. The wedge-like shape of water in this perimeter area will reduce horizontal forces between the flood current and the present invention building structure, and thereby reduce the horizontal forces required to maintain the position of the present invention building over concrete slab 2 .
[0012] The horizontal positioning of the present invention building at any flood water level (W 2 or other) is provided by vertically-extending poles 4 , and the building will be guided in relation to these poles 4 without interference to the changing vertical position of the building. The choice of cross-section for poles 4 is not limited by this invention. It is contemplated that both the rectangular tube and round cross-section would be favored for practical and economical reasons. The rectangular-shaped hollow tube spaces 9 that permit the present invention building structure to slide up and down in relation to the fixed poles 4 would also having a corresponding structure, rectangular, round, or other cross-section. The present invention building structure, marked in FIG. 2 as upper region 5 and base 6 , must be a rigid unit able to resist both flexion and torsion forces without significant deformation. The number 7 indicates he possible locations of internal walls, also called separations. It is a major advantage, if the internal walls 7 are rigid, tightly connected to the external walls and contribute to the combined rigidity of the building's upper region 5 . High structural rigidity is essential, because a deformed building structure would adversely interact with poles 4 when the building is lifted by the flood waters, and could prevent the desired amount of lifting. For example, as shown in FIG. 3 , the present invention building structure may be equipped with rectangular-shaped hollow tube spaces 9 that permit the building structure to slide up and down without interference in relation to fixed poles 4 also having a rectangular cross-section. FIG. 3 shows for example a possible solution for the horizontal cross-section in one corner of the present invention building wherein a rectangular hollow tube 9 surrounds the pole's 4 rectangular cross-section, the same corner indicated in FIG. 1 by the letter “B”. A minimum all around gap must be maintained between the hollow tube 9 and the pole 4 to avoid rubbing and possible damage.
[0013] In order to ensure a smooth relative movement between the building structure 5 and 6 and the poles 4 , rolling contact units ( 13 + 14 ) in accordance with FIGS. 4 , 5 , 6 and 7 are a suggested feature of the present invention. FIGS. 4 and 5 show the rolling contact units ( 13 + 14 ) configured for poles 4 with rectangular cross-section, while FIGS. 6 and 7 are drawn to illustrate a round pole 4 application. A rolling contact unit consists of four rollers 13 centered on shafts 14 . In the examples illustrated in FIGS. 4-7 , the desired positioning of a pole 4 within its associated hollow tube 9 is shown to include four rollers 13 per rolling contact unit. Nevertheless, other number of rollers 13 may be selected without limiting this invention. FIG. 2 shows only one rolling contact unit ( 13 + 14 ) per pole 4 . Two or more rolling contact units ( 13 + 14 ) may be used per pole 4 to achieve a more precise positioning of pole 4 within its associated hollow tube 9 .
[0014] FIG. 2 also shows that the lower region of the present invention building structure, its base 6 , contains several chambers ( 10 + 11 ). These chambers ( 10 + 11 ) may have different purposes. Some of the chambers ( 10 + 11 ), for example, those chambers marked with the number 10 and located near the perimeter of base 6 , may be air or foam filled spaces providing the necessary buoyancy for the present invention building as a whole. In the alternative, other chambers 11 may be used as a septic tank or as a drinking water reservoir, or as places for storing electrical batteries or fuel (not shown). Partitions between these chambers ( 10 and 11 ) are beneficial also from the point of view of structural rigidity, which as mentioned above is important to the present invention.
[0015] Furthermore, rain water collected by the gutters 18 shown in FIG. 2 will be led into a water reservoir, which although not individually marked in FIG. 2 will occupy at least one of the four chambers 11 visible in FIG. 2 , providing the emergency water supply needed by present invention inhabitants after flood waters have receded. Photovoltaic panels 8 on the roof (shown in FIG. 2 , but not individually marked by numerical designation) will be used to charge the earlier mentioned electrical batteries, which are preferably located in the chambers 11 to lower the center of gravity of the present invention building and increase its stability. The direct current (DC) power available from any batteries used can be transformed through inverters into 110 , 220 or other needed voltages. Alternate electric energy sources could include wind driven turbine-generator sets with engine driven generators. The fuel for the engine driven generators, as well the engine driven generator sets, should preferable be located in the lower region of the present invention building, for example in one of the chambers 11 in base 6 . However, the most likely solution for providing electrical power to the present invention building would be photovoltaic panels 8 placed upon the roof of the present invention building (one example of which is shown in FIGS. 1 and 2 ), due to their simplicity and minimal maintenance. In accordance with this invention, the stored electrical energy will be used among other applications to activate sump pumps (not shown) for removing water accumulation that is very likely to occur in some lower locations of the present invention building or its base 6 . Furthermore, it is contemplated for in this invention to have an automatic electronic control system that will operate pumps to transfer water, waste in the septic tank, or engine fuel between different chambers ( 10 + 11 ) in base 6 in order to maintain a balanced, horizontal positioning for the present invention building, while compensating for the changing flood water currents and wind pressure.
[0016] With use of this self-contained present invention building, the survival of its inhabitants is greatly improved as a result of having their own energy supply and water supply, as well as through the hygienic and autonomous storage of the sewage. The features described above for the present invention building structure intend to serve this purpose. A great advantage of the described self-contained and floating building structure system, is that the transition from regular operation to emergency operation can occur almost instantaneously when the present invention building begins to separate form the ground and rise with the surrounding flood water. If the present invention building is supplied with external water, electricity, and sewer utilities under normal conditions, these connections (shown by the numbers 16 and 17 in FIG. 2 ) must be disconnected under flood or other disaster conditions. Some of these connections may be automatically severed, and connection openings automatically closed, when the present invention building is lifted by the rising water. Some other connections may be de-activated manually, by an automatic control, including electrical control systems and pneumatic control systems. The layout and choice of the automatic disconnection and closing devices is not a limiting factor for this invention.
[0017] From engineering point of view, the contradicting requirements on high structural rigidity and minimum weight can be achieved in accordance with this invention by using materials with low specific density, such as aluminum alloys and composites. Application of foams of plastic and similar materials filing the empty structural spaces (for example in separating walls 7 ) in building 5 , as well as in base 6 to separate the chambers 10 and 11 , with provide strong adhesion between these fill materials and the structural materials to increase the mechanical rigidity and stability of the present invention structure. A secondary objective of the foam is to fill empty spaces which otherwise might become filled by intruding leakage. The leakage water would reduce the building's buoyancy and disturb the balance of the building as a whole. The two main components in the present invention building are its structural components and the space filing foam, and each shall be chosen to achieve the highest possible corrosion resistance and minimal deterioration due to aging factors, such as temperature, stresses, and other influences. Use of an aluminum alloy as building material is the attractive choice. However, it must targeted, that the aluminum alloy selected for use must have an optimum combination of strength and corrosion resistance, as the floodwater may have different concentrations of salt and other materials greatly influencing the fluid's corrosiveness. Conversely, exposure to the corroding fluid may be regarded' as a temporary and/or extraordinary event. Furthermore, the structural materials in lower region of the building, base 6 , and in other upper parts 5 of the present invention building structure may be different. For example, the lower region, the base 6 , which will be submerged into the flood water, may be built of steel while the upper parts of the building 5 can be made of aluminum alloys. Another preferred feature of this invention is for all surfaces of the building and poles 4 to be equipped with a corrosion resistant coating. | An aluminum-foam structural housing unit that is storm-proof, self-contained, and built to withstand natural disaster conditions resulting from hurricanes, tornadoes, earthquakes, and fire, and then assist its inhabitants immediately thereafter when interruptions in public utility system service can be experienced. The combined use of aluminum alloy and foam as its building materials gives the unit its great strength, as well as the versatility needed to face natural disaster conditions while providing absolute resistance to heavy winds, flooding, earthquake and fire. Since the unit is buoyant, during flooding conditions it lifts from the ground and is guided by vertical poles to maintain a horizontal orientation. The unit also automatically disconnects from public utility systems as lifting occurs, and it then provides its inhabitants with self-contained sources of water, electrical energy, and sewage management. Thus, the unit is designed to adjust to the flow of nature, instead of working against it. | 4 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This Non-Provisional Application claims the benefit of Provisional Application No. 61/347,401 filed May 22, 2010.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
REFERENCE TO SEQUENCE LISTING, A TABLE OR A COMPUTER PROGRAM LISTING COMPACT DISK APPENDIX
[0002] Not Applicable
BACKGROUND OF THE INVENTION
[0003] The present invention relates generally to smoke guards and more particularly to smoke guards that completely block the gap between the bottom of a door and the floor to prevent smoke and fire from entering a room through that gap in the event of a fire and to smoke guard accessories that further protect people trapped in a room during a fire.
[0004] The background information discussed below is presented to better illustrate the novelty and usefulness of the present invention. This background information is not admitted prior art.
[0005] As a safeguard against the threats posed by a fire, ideally, there should always be two means of exit from a room. In commercial buildings, especially in high rise buildings, this is often not the case. When there is only one exit from a closed room and a fire alarm sounds, before opening the door in an attempt to exit the building, the first thing one is advised to do is to check the temperature of the door leading out of the room. If the door feels cool all the way to the bottom of the door and if no smoke is leaking into the room from openings about the door, then the door should be slowly opened to check if there is a safe path to exit the building.
[0006] If the door is warm or hot to the touch, it is likely that the fire is too close to safely attempt opening the door. In this case, as quickly as possible, one should seal all of the openings around the door to prevent smoke and fire from coming into the room from the space at the bottom of the door. Smoke and poisonous gases are the number one killer in a fire, so preventing smoke from entering the room is of utmost importance. Most doors, especially doors in hotels and office buildings, have mandated gaps between the bottom of the door and the floor. Often, it is suggested to use a wet towel to plug the open space at the bottom of the door and, lacking a wet towel, anything that is available should be used. The openings about the sides of the door should also be sealed. It is advised to do this by using masking tape or the like.
[0007] If there is a fire and there is a window that provides a safe exit, it should be used to exit the building. It is often the case that windows are the windows of a high-rise apartment or office building and unless there is a fire-escape within reach, window exist is not a viable option. Aerial ladders on fire trucks are about 100 feet in length, however, it is not usual for fire truck ladders to reach to that height, even when extended, because of the distance from the building the fire truck must be parked. If fire-fighters are unable to reach a room from the outside, persons in the room will have to stay in the room and try to keep the smoke and fire from entering the room. A telephone or a cell phone should be used to alert others to the situation. Although tempting, there is real danger in breaking a window to call for help as an open window will provide a draft that may encourage the fire.
SUMMARY
[0008] When the present Inventor realized that: (1) most doors are mandated to have a gap of about an inch between the bottom of the door and the floor, (2) that this gap presents an opening for smoke, fire, and dangerous gases to enter a room even when the door is closed the floor, and (3) in the event of a fire having a recommended “wet towel” available to stuff into the gap is unlikely, he devised a set of inventive principles to provide a device for sealing the gap beneath a door.
[0009] The invention principles taught herein provide for a smoke guard device constructed of compressible/expandable material covered by fire resistant cloth, said device so arranged that when inserted into a gap between the bottom of the door and the floor prevents any smoke from traversing the gap. The device, referred to as a “smoke guard”, is easy to use, fills the space entirely, will not burn, and is impervious to smoke and gas. The set of invention principles, as described herein, provides for various styles and sizes of the device and also provides for smoke guard accessories. One accessory comprises a set of self-adhering intumescent material strips to be placed over side and top of door openings to further secure a closed room from smoke. Once a room is secured from the entry of smoke, gas, and flame, the smoke guard package of accessories includes reflective tape to be adhered to a window to give notice to emergency rescue personnel that there is someone in that room that needs to be rescued, a light means, such as a flashlight, and/or a glow-light that lasts 12 hours without a battery or other power.
[0010] One example of the smoke guard is designed for use with a metal door and consists of a length of high material rated to withstand high temperature and that is smoke, gas and moisture impermeable, where one end of the length of material is wrapped about and fixed to a piece of memory foam with the other end of the length of cloth being wrapped about and fixed to a length of magnetic material. The memory foam end is easily positioned within the space between the bottom of the door and the floor keeping the end with the magnet lying on the floor. The immediate expansion of the foam, once the guard is positioned in the open space, assures that the space is completely filled and blocked. To double the protection of the smoke blocking foam containing end that is stuffed under the door and to assure that the smoke guard is not blown out of its position by force of air created by the fire, the magnet end of the smoke guard is lifted up and placed against the door so that the magnet holds the device tight to the door.
[0011] Another example of the present invention is designed for use with a wooden door, and like the example that is designed for a metal door, the example designed for use with a wooden door also consists of a length of high temperature material that is smoke, gas and water impermeable, where a first end of the length of material is wrapped about and fixed to a piece of memory foam with a second end of the length of cloth being wrapped about and fixed to a length of magnet. The memory foam end is easily positioned within the space between the bottom of the door and the floor keeping the end with the magnet lying on the floor. This example comes with a strip of magnetic metal that is affixed to the inside of the wooden door near the bottom of the door so that once the smoke guard is in place, there is a magnetic strip to accept the magnetic end of the smoke guard. Alternatively, the device is provided with a strip of tape to adhere the second end to the door to further enhance the life and effectiveness of the device.
[0012] Yet another way to use the present invention is to have it installed within the body of the door so that the bottom edge of the invention is parallel and in the same plane as the bottom of the door. In this embodiment, when the smoke guard is needed, a user simply has to pull down on the set of handles that extend through the inner-surface of the door and are attached to a metal plate that forms the top surface of the device, to release the device so that when the handles are activated, the smoke guard is pulled down into the space between the bottom of the door and the floor.
[0013] IBC (International Building Code) 2006 mandates that the smoke guards of the present invention be tested in accordance with UL1784 for smoke and draft-control doors having an artificial bottom seal installed across the full width of the bottom of the door assembly. The air leakage rate of the door assembly shall not exceed 3.0 cubic feet per minute per square foot of door opening at 0.10 inch (24.9 Pa) of water for both the ambient temperature test and the elevated temperature exposure test. Additionally, all fire doors with shutter assemblies shall be constructed of any material or assembly of component materials that conforms to the test requirements of Section 715.4.1, 715.4.2 or 715.4.3 and the fire protection rating indicated in Table 715 . 4 . Fire door assemblies and shutters shall be installed in accordance with the provisions of this section and NFPA 80.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] In order that these and other objects, features, and advantages of the present invention may be more fully comprehended, the invention will now be described, by way of example, with reference to the accompanying drawings, wherein like reference characters indicate like parts throughout the several figures, and in which:
[0015] FIG. 1 is a plan view illustrating the basic construction of a smoke guard embodiment of the present invention.
[0016] FIG. 2 is a side view of the present invention as illustrated in FIG. 1 .
[0017] FIG. 3 is a perspective diagrammatic sketch illustrating one way to make the device according to the principles of the present invention.
[0018] FIG. 3 a is a perspective diagrammatic sketch illustrating a smoke guard device made according to the principles of the present invention.
[0019] FIG. 3 b is a perspective diagrammatic sketch illustrating a smoke guard device in use according to the principles of the present invention.
[0020] FIG. 4 is an elevation view of a wooden door with a magnetic strip attached.
[0021] FIG. 5 is a diagrammatic view of an embodiment of the present invention that is installed within the body of the door.
[0022] FIG. 6 is a sketch of a wall with a door and window to show the use of the accessories according to the inventive concept.
REFERENCE CHARACTERS AND PARTS TO WHICH THEY REFER
[0000]
2 A fold line.
4 A sew line.
6 A fold line.
10 An example of the present invention.
12 High temperature cloth.
13 Area of high temperature cloth 12 onto which foam 18 will be positioned.
14 Two sided-tape.
16 Magnetic material.
18 Compressible/re-expandable material, for example foam.
20 Intumescent.
30 Wooden door.
32 Magnetic strip.
60 Open space at bottom of door.
72 Tape.
74 Iridescent or fluorescent tape.
76 Flashlight.
80 Window.
82 Wall.
100 An example of the present invention.
110 A door with a hollow bottom.
112 Top surface of present invention.
114 Releasing handle.
116 Hollow door volume.
DEFINITIONS
[0046] Attachment materials, as used herein, refers to tapes, double-sided tapes, glues, adhesives, staples, sewing means, pins, and magnets, including any other means, known or yet to be known, to fasten materials together.
Fire retardant foam, as used herein, refers to any lightweight self-expanding materials that when compressed will re-expand and are formulated to contain flame-retardant additives or to be being inherently non-flammable and also may have the properties of low smoke density, low toxic gas emission, low heat release, enhanced chemical and solvent resistance, high levels of structural rigidity, chemical stability, UV-resistance, and will not absorb water.
High-temperature cloth, as used herein, refers to any high-temperature cloth or blanket, that is flexible, strong, protective, and fire-resistant, including but not limited to continuous filament, amorphous silica yarns, polymeric material, fiberglass reinforced polymeric material, high-temperature resistant woven textiles, metallized cloth including stainless steel and aluminum foil, and may also include impermeable material.
High-temperature thread, as used herein, refers to any thread that is fire-resistant or any thread that will not support combustion, such as a ceramic thread.
Impermeable membrane, as used herein, refers to a material that does not allow the passage of a fluid, such as water, other liquids, and/or gases, including smoke. The impermeable material disclosed herein includes a flexible, fluid-impermeable, sealing layer that is used for waterproofing by applying one or more layers of the membrane material onto a surface and/or object to be protected. Such impermeable blanket layers are made of a variety of materials, such as, but not limited to, silicone, fiberglass fabric coated with silicone rubber, coal tar, bitumen and synthetic polymers that are formed as sheet-like substances of desired sealing properties. Material and substance properties of impermeable membranes used herein meet the requirements of any particular structure, building, authority, climate, chemical and physical environment, required durability, cost effectiveness and the like.
Intumescent, as used herein, refers to those materials having properties that cause them to expand (or intumesce) to several times their original size when activated by high temperatures to prevent the spread of flames and smoke to other parts of a building, for example passive fire-seals contain intumescent compounds. The intumescent material is available in many forms and may be, for example an intumescent layer, mat, strip, or paste, such as a caulking material.
Magnetic material, as used herein, refers to materials that are magnetized and create their own persistent magnetic field. Materials that can be magnetized, and, thus, are strongly attracted to a magnet, are called ferromagnetic and include iron, nickel, cobalt, alloys thereof, some alloys of rare earth metals, and some naturally occurring minerals such as lodestone.
Seaming, as used herein, refers to connecting one part to another part, for example where a cloth is folded and the two parts of the cloth that have been brought together by the folding are subsequently “seamed” together along a predetermined line. The seaming may utilize stitching, using an adhesive, stapling, pinning, or any other means that will connect the two parts to each other.
DETAILED DESCRIPTION
[0047] To provide an understanding of the basic structure of the smoke guards made according to the principles of the present invention, we refer now to the drawings. It should be noted that the disclosed invention is disposed to versions in various sizes, such as lengths, widths, and depths to accommodate the variety of sizes of door spaces, in addition to variation in shapes, contents, number and composition of layers, materials, and attachment means. Therefore, the versions described herein are provided with the understanding that the present disclosure is intended as illustrative and is not intended to limit the invention to the versions described.
[0048] If there is a fire outside of a closed room, it is a recommend to stuff a wet towel into the gap found between the bottom of the door and the floor space to provide at least a temporary safeguard against fire and smoke entering through that space. There are many problems with this; the wet towel must be of the right length, width, and thickness to fill all of the space. Moreover, in order for a towel to be wet there must be a water source in the room. This may be present in many, but not all, hotel rooms, and in some dormitory rooms, but is unlikely to be available in rooms of office buildings and in older hotels that have shared bathroom space. And even when water is available, it is very difficult to stuff a wet towel in the space under a door so that the entire space is blocked, and once the towel is in place, it is only a matter of time before the heat of the fire dries the towel and the towel ignites. Accordingly, the present invention provides a set of inventive principles that enables the manufacture of a device that completely seals the gap space found at the bottom of doors and in the following discussion, the present inventor provides several examples of his inventive concept. FIG. 1 , a plan view, and FIG. 2 , a side view, illustrate one example of the basic construction of a smoke guard device following the principles of the present invention. Smoke guard device 10 is designed to fill the mandated air-space between the bottom of a closed door and the floor when there is a danger of smoke entering the room. Device 10 , illustrated in FIG. 1 as a laid open device, includes a length of high temperature cloth 12 having the width of the door with which the device is to be used. High-temperature cloth 12 is impermeable to smoke, gases, and if desired, to moisture, as well, and is either treated with a fire-retardant or is manufactured of material that is fire-resistant or non-flammable, and is available in all required widths and lengths. At a determined distance from a first end of the length of the cloth, area 13 is set aside for receiving a strip of compressible/re-expandable material, i.e., foam, preferably fire-retardant foam. Although the foam strip may be adhered to the cloth using several different methods, the example provided uses the adhesive method. Across the width of the defined cloth area 13 , one surface of a strip of two-sided adhesive tape 14 is adhered to the cloth to receive and adhere one surface of a strip of compressible/re-expandable foam material 18 cut to match the dimensions of cloth area 13 . Once the strip of foam material 18 has been adhered to tape 14 , a second strip of two-sided adhesive tape 14 is positioned onto the opposing surface of the strip of foam material 18 . The first end of the length of high-temperature cloth 12 is then lifted up and folded, along fold line 6 , over foam material 18 so that the first end of the cloth completely covers the top and side edges of foam block 18 as indicated by the fold-up arrow illustrated in FIG. 2 . The folded-over section of the cover is, in this example, adhered to the second surface of two sided adhesive tape 14 that was positioned on the upper surface of the foam block 18 , as is illustrated in the perspective diagrammatic sketch illustrated in FIG. 3 . At a determined distance from the second end of the length of cloth 12 , magnetic material, such as the strip of magnetic material 16 that is used as an example in this illustration, is position on the cloth across the width of cloth 12 , as shown. Magnetic strip 16 is positioned at a distance from the second end of the length of cloth 12 that provides a sufficient length of cloth to fold up, along fold line 2 , and over magnetic strip 16 leaving a sufficient amount of cloth on each of the raw edges of the cloth to come into contact with each other after the second end is folded over the magnetic strip so that these edges may be securely stitched closed along sew lines 4 as illustrated by the fold arrows shown in FIG. 2 . It is to be understood that the method of attaching the metal to the cloth is by way of example and that other methods, known or yet to be know, may be used. The method used will depend on part on the magnetic material used. The cloth, itself, may be impregnated with a magnetic material, which would completely change the method of attaching a magnet to the material. In this example, magnetic strip 16 happens to be one inch thick, but it is to be understood that the thickness is determined by the properties of the materials being used, such as the magnetic property of a metal door and the corresponding magnetic property of the magnetic strip. This method, of course, is for use with a metal door or a door that has been adapted for magnetic attachment. The smoke guard is now ready for use. The type of foam used may be memory foam, although it is to be understood that the compressible/re-expandable material can be any material that re-expands when compressed. The compressible/re-expandable material, ideally, is impermeable to smoke, gases, and, if desired, to moisture and is either treated with a fire-retardant or is fire resistant or non-flammable. In this illustration, the foam that is used as the compressible/re-expandable material is 1½ inches thick. The thickness, of course, is to be determined by the height of the gap between the bottom of the door and the floor that must be blocked.
[0049] As indicated in FIG. 3 a , intumescent material 20 may be affixed to cloth 12 in the area of cloth 12 between magnetic strip 16 and compressible/re-expandable material 18 . Intumescent material 20 adds an additional level of protection against smoke or fire entering a room. Intumescent materials swell upon exposure to a certain degree of heat to assure that the smoke guard remains in place to securely prevent any ingress of smoke, gas, or fire. Additionally, intumescents are highly endothermic and contain a lot of chemically bound water, such as in the form of hydrates, and as this water is heated and released, it acts to cool adjacent materials, thus prolonging the time of protection.
[0050] To use the smoke guard, compressible/re-expandable foam 18 end is compressed and inserted in the space under the door. Once the space is completely filled by this foam containing end of the smoke guard, the compressible/re-expandable foam will re-expand to completely and securely fill all of the door-gap space. Magnetic strip 16 end of the smoke guard is then lifted up off of the floor and magnetically or adhesively 14 adhered to the door (refer to FIG. 3 b ).
[0051] If desired, the smoke guard can be made without the intumescent and without the magnetic strip. The protection offered by cloth 12 in conjunction with compressible/re-expandable material 19 is still significant.
[0052] There are many buildings that still have wooden doors. In order for a smoke guard equipped with a magnetic strip to be used to block the mandated gap 60 between the bottom of a wooden door and the floor, in an analogous fashion to the way the device is used with a metal door, the smoke guard is available with a flat magnetic strip that is fashioned for attachment to a wooden door. FIG. 4 , an elevation view of a door in place, illustrates how magnetic strip 32 may be attached to wooden door 30 . In the example illustrated, magnetic strip 32 is attached to wooden door 30 using attachments such as screws that are installed into screw holes 34 that are pre-drilled through strip 32 . It is to be understood that the method of attachment of magnetic strip 32 to door 30 can be any method of attachment, such as double-sided tape pre-applied to the device ready to be used to tape the device to the door. Any others that work to attach the magnetic strip to the door so that it can be used as intended are within the principles of the present invention. As with the metal door, the smoke guard for the wooden may be made and used without the additional safeguards of attaching the device to the door and/or without the use of intumescent. However, each of these added features provides extra protection against the entry of smoke or flames and increases the lifetime of the device during a fire event.
[0053] Another embodiment of the smoke guard made according to the principles of the present invention is illustrated in FIG. 5 . This “stored-in-door” embodiment is especially useful for new builds or for when doors are being replaced. A metal door is used in this illustration, although the door could be of wood, plastic, or any other material of which doors are made. In this example, at least the bottom-most section of the interior of the door is hollow 116 . Smoke guard 110 , made according to the principles of the present invention, is installed within the hollow space at the bottom of the door during, or after, the manufacture of the door. The door is fashioned with two apertures through which handles, levers, or control buttons 114 are positioned. Handles 114 are attached to the top plate 112 of smoke guard 110 in such a manner that when a user pulls down on handles 114 , the pulling force acts on top plate 100 to result in the transfer of smoke guard 110 to the floor. In this case, the compressible/re-expandable material is automatically placed into position to completely fill the gap between the bottom of the door and the floor. Smoke guard 110 is available with or without the magnetic strip and/or an application of intumescent.
[0054] Except for the “stored-in-door” model, smoke guard devices are available in their own container that is designed to hold the device until needed. So that the device is available when needed, it is able to be hung, or otherwise attached, to a wall or the back of a door. Smoke guards are also available in plastic-type bags, to be carried in a suit case for travelers to carry them when staying in buildings that may not have such a safeguard.
[0055] Some doors do not fit tightly in the confines of the door jam. In the event there are openings about the side or the top edges of the door, the smoke guard package includes self-adhering tape 72 that could be intumescent strips for placement over such openings, as illustrated in FIG. 6 , where tape 72 positioned over the door top and side opening is adhered to both door 30 and wall 82 . When exposed to heat intumescent strips expand to create an enhanced smoke barrier and also, as discussed above, upon expansion, the intumescent material releases water that reduces the temperature of the door. This is important in that most doors used in public building are only fire resistant rated from 20 minutes to 1½ hours. The smoke guard is rated for two or more hours, depending on the materials used in manufacture.
[0056] Many homes and apartments, hotels and hospitals are not in compliance with the requirements of the fire code. For example, hotels and tourist spots are infamous for not following the fire code requirements and for not maintaining their fire protection equipment properly. Having access to a smoke guard of the present invention is especially important in rooms from which there is no easy or safe egress. It is well-accepted that windows should not be opened in a fire because of the fire-drawing draft that an open window would create. Closed windows, however, may give one the feeling that no one knows that they are in the room and need to be rescued. To alleviate this concern, the smoke guard is available with strips of fluorescent tape 74 , or the like, to be placed on a window 80 to provide notice to emergency personnel. Also available is small flashlight 76 to use if it is dark and the lights go out and to alert emergency personnel to the situation and/or a glow-light, especially one that is rated to last for 12 hours and requiring no batteries.
[0057] Thus, it can be seen from the above that the Applicant is teaching an inventive concept that supplies all of the principles needed to provide for smoke guard devices that offer the means to keep smoke and flame from entering a room through the space that is mandated to be between the bottom of a door and the floor. Additionally, the principles include intumescent tape to seal the non-air tight spaces at the sides and top of a door, as well as aids such as reflective tape and a battery to provide notice to those outside the building that a person is trapped in the room. Moreover, as the smoke guards and accessories of the present invention may be constructed of presented available and permitted materials, the cost to manufacture is minimal, thus making these essential safety features, affordable.
[0058] The foregoing description, for purposes of explanation, used specific and defined nomenclature to provide a thorough understanding of the invention. However, it will be apparent to one skilled in the art that the specific details are not required in order to practice the invention. The disclosed descriptions and illustrations are not intended to be exhaustive or to limit the invention to the precise forms disclosed. Those skilled in the art will recognize that many changes may be made to the features, embodiments, and methods of making the versions of the invention described herein without departing from the spirit and scope of the invention, such as adjusting the template patterns shown in the drawings and described above to fit the variety of other similar, but different, multi-dimensional expansion joints, as well as to fit the various sizes of multi-dimensional joints that require fire barriers. Furthermore, the present invention is not limited to the described methods, embodiments, features or combinations of features but include all the variation, methods, modifications, and combinations of features within the scope of the appended claims. The invention is limited only by the claims. | A smoke-barrier device for under-door gaps is taught. A basic barrier comprises a unit of expandable/compressible material covered by one end of a length of fire-resistant and smoke and gas impermeable material, and is sized to completely seal the mandated gap beneath doors in the event of a fire. Another style includes magnetic material on the other end of the length of fire-resistant, moisture and gas impermeable material to further adhere the barrier to a metal door. Intumescent material may be fixed on the central part of the length of fire-resistant, moisture and gas impermeable material. The device is sized to fit commercial and private doors spaces and is offered in a kit including tape to place about top and sides openings of a door, luminescent tape to be placed on a window in the room, and a flashlight of various styles. The fire-resistant material may also be water impermeable. | 4 |
INTRODUCTION
The present invention relates to a process for the preparation of α-amino acids by hydrolysis of hydantoins in the presence of water and of at least one metallic oxide under conditions such that all the starting materials are completely dissolved in the water as a result of high pressure and high temperature and only one further phase is present in the reactor in addition to the solid phase of the metallic oxide.
BACKGROUND PRIOR ART
It is known from U.S. Pat. No. 2,557,920 that α-amino acids are formed by saponification of hydantoins using sodium hydroxide. However, such processes require at least 3 moles of sodium hydroxide per mole of hydantoin. The same is true when potassium hydroxide is used.
DE 19 06 405 describes the hydrolysis of 5-(2-methylmercaptoethyl)-hydantoin using an aqueous solution of alkali carbonate and/or alkali hydrogen carbonate. During the hydrolysis, ammonia and carbon dioxide are constantly removed. Of the alkali carbonates, potassium carbonate is preferred; a molar ratio of hydantoin to alkali of from 1:1 to 1:5 is used. The hydrolysis is carried out under pressure at from 120 to 220° C. The alkali methioninate solution is used to liberate D,L-methionine with carbon dioxide; the mother liquor from the separation of the methionine that has crystallized out is used again in the circuit for the hydantoin hydrolysis, optionally with the discharge of from 1 to 2%.
Processes for the preparation of α-amino acids from hydantoins without the simultaneous production of salts are described in JP 03-95 145A and in JP 03-95146A. In those processes, the hydantoins are saponified, with the addition of water and catalysts consisting of metallic oxides (e.g. TiO 2 , ZrO 2 ), at temperatures from 80 to 220° C. with elimination of ammonia. This is carried out discontinuously over a period of from 10 minutes to 10 hours in a stirred autoclave in which there is established a pressure corresponding approximately to the vapour pressure of water at the temperature which has been set. Accordingly, there are at least two phases in the autoclave: a liquid phase and a gas phase.
The processes described in JP 3-95145A and JP 3-95146A, which are carried out batchwise or continuously, lead, with the described dwell times, to the formation of numerous by-products in relatively high concentrations. Yields of max. 69% are mentioned for the preparation of methionine.
Another method for the continuous preparation of methionine without the preparation of a salt as by-product is described in FR-A 27 85 609.
Starting from the amino nitrile of methionine, which is hydrated, with the addition of a ketone (acetone) as homogeneous catalyst, to methionine amide at from 10 to 40° C., the methionine amide so obtained is hydrolyzed to methionine at from 100 to 180° C. A further possible method of carrying out that hydrolysis consists in a heterogeneously catalyzed reaction at about 100° C. and 1 bar, in which catalysts selected from TiO 2 , TiO 2 /Al 2 O 3 , Nb 2 O 5 , Nb 2 O 5 —Al 2 O 3 , ZnO and ZrO 2 can be used. The ammonia formed during the reaction is removed in that process.
The necessary addition of a ketone for the saponification of the amino nitrile of methionine to methionine amide requires further expensive working-up steps.
SUMMARY OF THE INVENTION
An object of the invention is to provide a process for the preparation of α-amino acids in which hydantoins are saponified without the formation of waste salts, and the α-amino acids are obtained in a high yield.
The present invention provides a process for the preparation of α-amino acids by hydrolysis of hydantoins of the general formula
in which
R 1 , R 2 : which may be identical or different, and represent hydrogen, alkyl having from 1 to 6 carbon atoms, especially methyl, ethyl, propyl, straight-chain or branched chain; or alkylene radicals having from 1 to 6 carbon atoms which are closed to form a ring when R 1 and R 2 represent alkylene; or, when R 1 or R 2 represents alkylene, are bonded to methylthio, mercapto, hydroxyl, methoxy, amino groups or halogen atoms, especially fluorine or chlorine,
R 1 or R 2 : represents a phenyl group which is optionally substituted by methyl, hydroxyl groups or halogens, especially fluorine or chlorine, in the presence of water, ammonia and at least one metallic oxide as catalyst, selected from the group consisting of TiO 2 , TiO 2 /Al 2 O 3 , Nb 2 O 5 /Al 2 O 3 , ZnO and ZrO 2 , in a saponification reactor under conditions in which all the starting materials are completely dissolved in the water and only one further phase is present in the reactor in addition to the solid phase of the metallic oxide.
The terms alkylene or alkylene radical mean to a divalent saturated hydrocarbon radical.
R 1 and R 2 preferably represent:
R1 hydrogen,
R2 isopropyl, 2-methylpropyl, phenyl or hydrogen,
so that valine, leucine, phenylalanine or glycine are formed from the hydantoins by saponification.
Particular preference is given to the hydantoin in which R 1 or R 2 represents hydrogen and R 2 or R 1 represents the 2-methylthioethyl radical, so that methionine is prepared as the product.
DETAILED DESCRIPTION OF INVENTION
The reaction (hydrolysis, saponification) is generally carried out at a temperature of from 120 to 250° C., preferably from 150 to 210° C., and a pressure of from 80 to 300 bar, especially from 110 to 200 bar. Under those conditions, the reaction mixture (hydrolysis mixture) is in a state in which the interface between the liquid phase and the gaseous phase disappears.
Reaction-slowing transport resistances at phase boundaries other than the surfaces of the solid oxides are accordingly no longer present.
This is manifested by a short reaction time, which is generally in a range of from 10 to 120 seconds, especially from 20 to 80 seconds.
The hydrolysis is generally carried out in the presence of from 5 to 40 moles of NH 3 , especially from 25 to 35 moles, based on moles of hydantoin.
In a preferred embodiment, the hydantoin-containing solution fed into the reactor already contains carbon dioxide in an amount of from >0 to 10 wt. %, particularly from 0.2 to 7 wt. %, especially from 0.4 to 5 wt. %, based on the total amount of solution.
Ammonia or a gaseous ammonia/water mixture is generally fed into the saponification reactor or reaction zone at a temperature of from 180 to 500° C., preferably from 210 to 360° C., and a pressure of from 80 to 300 bar, especially from 110 to 200 bar, as is the above-mentioned hydantoin-containing solution, which optionally contains CO 2 .
The ammonia/water mixture generally consists of from 5 to 50 wt. %, especially from 2.5 to 40 wt. %, ammonia, the remainder consisting of water.
The hydantoins are generally present in the hydrolysis mixture in a concentration of from 150 to 600 g/l, especially from 200 to 450 g/l.
Ammonia or an ammonia/water mixture is preferably mixed with the hydantoin- and optionally carbon dioxide-containing solution, and the mixture is then fed into the reactor, with the desired pressures and temperatures, as mentioned above, being established (hydrolysis mixture).
Any suitable reactor can be used for purposes of the invention.
In general, in order to prepare that mixture, the hydantoin-containing solution at a temperature of from 20 to 80° C. and at from 80 to 300 bar, especially from 110 to 200 bar, is mixed with an ammonia/water mixture that is at from 180° C. to 500° C. and from 110 to 200 bar, especially from 130 to 200 bar, so that the desired reaction temperature and the desired pressure are established when the mixture is fed into the reactor.
The hydantoin-containing solution preferably originates from the reaction mixtures obtained after synthesis and preferably already contains carbon dioxide.
The oxidic catalyst is used in various forms, either in powder form, shaped in the conventional manner or in the form of a fixed bed.
It has been found that TiO 2 in the crystalline form anatase is particularly suitable.
In general, the chosen catalyst is used in an amount of from >0 to 0.1 kg, preferably from 0.001 to 0.05 kg, based on 1 kg of the hydantoin used.
Following the saponification of the hydantoin, which is carried out continuously or batchwise, ammonia and carbon dioxide are separated from the liquid phase in a suitable apparatus with a portion of the water in vapour form.
The portion of the water/ammonia/carbon dioxide mixture formed in the saponification reaction is preferably returned to the hydantoin synthesis or fed to the saponification process again in the desired amount.
The aqueous mixture obtained after separation generally contains from 10 to 40 wt. %, based on the total amount, of the desired α-amino acid.
The α-amino acid is crystallized out by known means and separated from the mother liquor.
The mother solution containing as yet unreacted hydantoins is returned to the hydrolysis process and mixed with fresh hydantoin-containing solution upstream of the reactor. The mother solution generally accounts for more than about 30 vol. % of the reaction mixture, which contains a corresponding amount of fresh hydantoin-containing solution. In order to avoid the concentration of any by-products which may be present, from 1 to 2 vol. % of the mother liquor are generally discharged.
In the process according to the invention it is possible, especially also when preparing methionine, to use mixtures that contain up to 10 wt. % of by-products from the hydantoin synthesis, without any loss in yield.
EXAMPLES
Example 1
A solution heated to 60° C. and containing 20 wt. % 5-(2-methylmercaptoethyl)-hydantoin and 3 wt. % CO 2 in water, which solution contains a considerable amount of impurities in the form of 5-(2-methylmercaptoethyl)-hydantoic acid and 5-(2-methylmercaptoethyl)-hydantoic acid amide, methionine amide, methionine nitrile and methylmercaptopropionaldehyde cyanhydrin, imino nitrile and polymers, is continuously mixed, in a ratio of 4:7, at a pressure of 150 bar, with a solution heated to 250° C. and consisting of 25 wt. % ammonia and 75 wt. % water. This mixture then has a temperature of about 180° C. and is introduced into a reactor which has been adjusted to a temperature of 180° C. and is filled with catalyst. The catalyst consists of TiO 2 in the crystalline form anatase. The dwell time of the reaction mixture inside the reactor is set at 70 seconds. The liquid product mixture so obtained contains, downstream of the reactor, about 4.1 wt. % methionine, 4.9 wt. % methionine amide and 1.9 wt. % unreacted 5-(2-methylmercaptoethyl)-hydantoin. The molar yield of methionine, based on the amounts of 5-(2-methylmercaptoethyl)-hydantoin entering the reactor, is more than 63%. Downstream of the reactor, the pressure of the solution is brought to ambient pressure, and water, CO 2 and ammonia are partially separated off. The methionine is crystallized out from the resulting mother liquor and filtered off. The purity of the separated and dried methionine is greater than 95%.
Example 2
The procedure of Example 1 was followed, but the temperature of the ammonia/water mixture was set at 200° C. and the temperature in the reactor was set at 145° C. The liquid product mixture so obtained contains, downstream of the reactor, about 2.3 wt. % methionine, 2.2 wt. % methionine amide and 5.2 wt. % unreacted 5-(2-methylmercaptoethyl)-hydantoin. The molar yield of methionine, based on the amounts of 5-(2-methylmercaptoethyl)-hydantoin entering the reactor, is more than 35%.
Example 3
The procedure of Example 1 was followed, but the temperature of the ammonia/water mixture was set at 300° C. and the temperature in the reactor was set at 210° C. The liquid product mixture so obtained contains, downstream of the reactor, about 2.9 wt. % methionine, 0.5 wt. % methionine amide and 0.1 wt. % unreacted 5-(2-methylmercaptoethyl)-hydantoin. The molar yield of methionine, based on the amounts of 5-(2-methylmercaptoethyl)-hydantoin entering the reactor, is more than 45%.
Example 4
A solution (starting material) heated to 60° C. and containing 19.5 wt. % 5-(2-methylmercaptoethyl)-hydantoin and 2.8 wt. % CO 2 in water, which solution contains a considerable amount of impurities in the form of 5-(2-methylmercaptoethyl)-hydantoic acid and 5-(2-methylmercaptoethyl)-hydantoic acid amide, methionine amide, methionine nitrile and methylmercapto-propionaldehyde cyanhydrin, imino nitrile and polymers, is continuously mixed, in a ratio of 1:1, at a pressure of 150 bar, with a solution heated to 305° C. and consisting of 29 wt. % ammonia and 71 wt. % water. This mixture then has a temperature of 180° C. and is introduced into a reactor which has been adjusted to a temperature of 180° C. and is filled with catalyst. The catalyst consists of TiO 2 in the crystalline form anatase. The dwell time of the reaction mixture inside the reactor is set at 80 seconds. The liquid product mixture so obtained contains, downstream of the reactor, about 3.4 wt. % methionine, 4.8 wt. % methionine amide and 6.0 wt. % unreacted 5-(2-methylmercaptoethyl)-hydantoin. The molar yield of methionine, based on the amounts of 5-(2-methylmercaptoethyl)-hydantoin entering the reactor, is more than 40%. Downstream of the reactor, the pressure of the solution is brought to ambient pressure, and water, CO 2 and ammonia are partially separated off. The methionine is crystallized out from the resulting mother liquor and filtered off. The purity of the separated and dried methionine is greater than 85.5%.
The filtrate that remains is mixed with fresh starting material in a ratio of 10:3. A portion of the ammonia/CO 2 /water mixture previously separated off is compressed at 150 bar again and heated to 320° C. and fed into the mixture of filtrate and starting material at 150 bar.
That mixture is again introduced into the reactor adjusted to a temperature of 180° C. and filled with catalyst, the temperature and the dwell time corresponding to those of the first pass. The liquid product mixture so obtained contains, downstream of the reactor, about 3.7 wt. % methionine, 4.3 wt. % methionine amide and 3.8 wt. % unreacted 5-(2-methylmercaptoethyl)-hydantoin. The molar yield of methionine, based on the amounts of 5-(2-methylmercaptoethyl)-hydantoin entering the reactor, is more than 73%.
Downstream of the reactor, water, CO 2 and ammonia are partially separated off again and the pressure of the solution is brought to ambient pressure. The methionine is crystallized out from the resulting mother liquor and filtered off. The purity of the separated and dried methionine is greater than 85.1%.
Further modifications and variations of the foregoing will be apparent to those skilled in the art and are intended to be encompassed by the claims appended hereto.
German priority application 102 38 212.3 of Aug. 21, 2002 is relied on and incorporated herein by reference. | A process for the preparation of α-amino acids by hydrolysis of hydantoins in the presence of water and at least one metallic oxide under conditions such that all the starting materials are completely dissolved in the water as a result of high pressure and high temperature and only one further phase is present in the reactor in addition to the metallic oxide phase. | 2 |
This application is a division of, and claims priority to, application Ser. No. 09/385,442, filed Aug. 30, 1999, now U.S. Pat. No. 6,200,954 B1. Ser. No. 09/385,442 claimed priority to provisional application Ser. No. 60/099,313, filed on Sep. 4, 1998.
FIELD OF THE INVENTION
The present invention involves small peptides that function as potent angiogenic inhibitors. In particular, the invention relates to small peptides that can be synthesized by enzymatic or chemical methods. In addition, the invention relates to use of the small peptides to inhibit angiogenesis, to treat angiogenesis-related diseases, and to inhibit endothelial cell proliferation and reduce tumor growth.
BACKGROUND OF THE INVENTION
Angiogenesis is the process of new blood vessel formation from pre-existing vessels, involving endothelial cell proliferation, migration and assembly into tubule structures (31). It plays important roles in many normal physiological functions such as embryonic development and wound healing (1). In addition, inappropriate angiogenesis is also associated with various pathological conditions including solid tumor growth and metastasis, rheumatoid arthritis and psoriasis (2). Many molecules that inhibit tumor angiogenesis have been shown to inhibit tumor growth including antibodies against angiogenic factors, natural and synthetic compounds that inhibit angiogenesis, and the natural angiogenic inhibitors like the angiostatin and endostatin proteins produced by tumor cells (3-8). Anti-cancer therapy by inhibiting tumor angiogenesis is called anti-angiogenic therapy and has shown great potential as an effective new method for treating cancer, especially solid tumors (9).
Plasminogen is a plasma glycoprotein synthesized mainly in the liver. It is the precursor of the serum protease plasmin that plays important roles in the fibrinolytic system and clot dissolution (10). At the amino terminus, plasminogen contains five homologous repeats that form looped “kringle” structures held together by disulfide bonds. Plasminogen binds to fibrin through lysine binding sites located on the five kringle domains (k1 through k5) (10). Each kringle domain is about 80 amino acids in length and different kringle domains are highly homologous to each other in amino acid sequences. A naturally occurring fragment of plasminogen containing the first four kringle domains (k1-k4) has been isolated from serum and urine of mice bearing a low metastic Lewis lung carcinoma. This plasminogen fragment has been named angiostatin (equivalent to amino acids 98-440 of murine plasminogen) and is a potent angiogenesis inhibitor that can inhibit endothelial cell proliferation as well as tumor growth and metastasis in mice with no obvious toxicity (5, 6, 11). Furthermore, recombinant individual kringle domains or their combinations expressed in E. coli have been found to be able to inhibit endothelial cell proliferation to various degrees with k5 the most potent, followed by k1 and k3 (12, 13). The k5 domain is not present in the naturally existing angiostatin protein but recombinant k5 also functions as an angiogenic inhibitor by inhibiting endothelial cell proliferation, migration as well as inducing cell cycle arrest and apoptosis (13, 32, 33). All these studies indicated that the integrity of the kringle structures and its proper folding are critical in maintaining the kringle domain's as well as angiostatin's functions as angiogenic inhibitors.
Endostatin is a protein first identified from a hemangioendothelioma cell line in 1997 (17). It is a 20 kDa C-terminal fragment of collagen XVIII, a novel collagen that consists of a N-terminal region, a series of collagen-like domains with interruptions and a 35 kDa C-terminal noncollagenous domain (18,19,20). Recombinant endostatin functions as a potent angiogenesis inhibitor in vitro as well as in vivo (17). Systemic administration of endostatin to tumor bearing mice regressed the primary tumor without inducing drug resistance (21). Recently, endostatin was found to be a zinc-binding protein and the zinc-binding is essential for its antiangiogenic activity (22, 23). Human clinical trials of endostatin started in September, 1999.
Vascular Endothelial Growth Factor (VEGF) is a potent endothelial specific mitogen. VEGF functions through two high affinity tyrosine kinase receptors: FLT-1 or Vascular Endothelial Growth Factor Receptor Type 1 (FLT-1/VEGFR1) and FLK-1, also known as KDR or Vascular Endothelial Growth Factor Receptor Type 2 (FLK-1/VEGFR2) (26). Both receptors are specifically expressed in endothelial cells. FLT-1 and KDR/FLK-1 stimulate endothelial cell proliferation and migration by binding to these two tyrosine kinase receptors (24). VEGF is also known as vascular permeability factor due to its ability to induce vascular leakage (24). The ligand binding domains of the two receptors as well as the receptor binding sites of VEGF have been studied by site-directed mutagenesis and X-ray crystallography (25-28). VEGF binds its two receptors through different amino acid contacts (25). The first three immunoglobulin loops of the FLT-1 receptor seem to be the main area responsible for VEGF binding (29, 30). The signal transduction triggered by VEGF through its receptors play critical roles in both physiological angiogenesis as well as pathological angiogenesis such as solid tumor growth and metastasis by stimulating embryonic angiogenesis and tumor angiogenesis. An anti-VEGF monoclonal antibody has been shown to inhibit tumor growth in mice by reducing the vessel density of the tumor (14). Likewise, trans-dominant mutants of both receptors have been shown to inhibit tumor growth in mice (15).
Protein-protein interactions are crucial to many physiological and pharmacological processes. They are specific and exhibit high affinity interactions due to molecular recognition sites found on the surface. It has also been observed that proline residues are sometimes found at the ends of the linear sequences that constitute the site of a protein-protein interaction. It has been shown that the probability of finding proline residues in the flanking segments of the protein-protein interaction sites is 2-3 times that of their random distribution. And the proline residues are not normally present within the interaction sites, but in the flanking segments. They are not directly involved in the interaction between proteins (14, 15).
SUMMARY OF THE INVENTION
The invention provides compositions comprising the peptides that are effective in inhibiting undesirable angiogenesis. The invention includes small peptides that have the ability to inhibit bovine aorta endothelial cell proliferation in the presence of basic Fibroblast Growth Factor (bFGF) in vitro. They can also inhibit angiogenesis in the chick chorioallantoic membrane (CAM) in vivo. The peptides of the invention are typically less than 20 amino acids in length. They preferably contain proline residues at each end or penultimate thereto. Peptides of the invention can be identified within the kringle domains of plasminogen or within the amino acid sequences of endostatin, VEGF, and VEGF receptors, especially FLT-1 and KDR/FLK-1.
Some preferred peptides of the invention are named Angio-1, Angio-2, Angio-3, Angio-4 and Angio-5 SEQ ID NOs: 1-3, 11, and 12 according to the plasminogen kringle domains they are derived from. Other preferred peptides are shown in the accompanying Sequence Listing (SEQ ID NOs: 29-50).
Small peptides from homologous regions of kringle 1 to kringle 5 have been designed. In accordance with this invention, such small peptides can function as angiogenic inhibitors in inhibiting chick CAM angiogenesis. Furthermore, one of the peptide Angio-3 derived from kringle 3, can inhibit BAE cell proliferation as well as tumor growth in nude mice. This finding is in direct contrast to the previous observation that the integrity of the kringle structures is required to maintain its anti-endothelial function.
Methods for preventing or treating undesirable angiogenesis, for example to prevent tumor metastasis or inhibit the growth of a primary tumor, by administration of compositions of the anti-angiogenic peptides, are also within the scope of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 . Inhibition of BAE cell proliferation by peptide Angio 3.
FIG. 2 . Inhibition of BAE cell proliferation by peptides Angio-2 and Angio-4.
FIG. 3 . Inhibition of chick CAM angiogenesis on 4 day embryo by Angio-3 at 120 ug/cover slip. The arrow indicates the inhibition of the growth of new vessels at the site of peptide application.
FIG. 4 . Inhibition of chick CAM angiogenesis on 4 day embryo by Angio-4 at 120 ug/cover slip. Arrows indicate the inhibition of the growth of new vessels at the site of peptide application.
FIG. 5 . Inhibition of chick CAM angiogenesis on 10 day embryo by Angio-2 at 12 ug/cover slip.
FIG. 6 . Control cover slip containing PBS on 10 day old chick embryo CAM. The arrow indicates the position of the control cover slip on CAM.
FIG. 7 . Inhibition of BAE cell proliferation by peptides Endo-1, Endo-2, Endo-3 and Endo-4.
FIG. 8 . Inhibition of chick CAM angiogenesis in 10 day embryo by Endo-4 at 1.8 μg/coverslip.
FIGS. 9A-9B . Inhibition of chick CAM angiogenesis in 13 day embryo by mVEGF peptide at various doses as indicated. Arrows indicate the inhibition of growth of new vessels at the site of peptide application. FIG. 9 A—0 hrs incubation; FIG. 9 B—40 hours incubation.
FIG. 10 . Antiangiogenic effect of peptides in the chick CAM assay. The number of positive inhibitions over the number of CAMs examined for each group are indicated above each bar.
FIG. 11 . Antiangiogenic effect of peptides in the chick CAM assay. The number of positive inhibitions over the number of CAMs examined for each group are indicated above each bar.
FIG. 12 . Inhibition of tumor growth in mice by peptide angio-3.
DETAILED DESCRIPTION OF THE INVENTION
Small peptides were designed according to the amino acid sequences of the kringle domains of human plasminogen or from the amino acid sequences of endostatin, VEGF, FLT-1 or KDR/FLK-1 using the “proline bracket model” described in references 14 and 15. The peptides were synthesized using a peptide synthesizer (Applied Biosystems, Inc., model 473A). The peptides were then purified by typical HPLC methods using a C18 reverse-phase column and eluting with an acetonitrile gradient.
Angiostatin-derived peptides of the present invention represent a portion of a kringle domain of plasminogen. The effective portion of a kringle domain is generally residues 30 to 38 or 39 of a kringle domain, numbered as in reference 13. However, it is acceptable to add additional amino acids to this generally effective core peptide. Thus, peptides representing residues 27 to 40 or 41 of a kringle domain would be expected to be effective. Preferred peptides of the invention are derived from human or mouse plasminogen. The exemplified peptides of SEQ ID NOS: 1-3, 11 and 12 represent residues 29-38 or 29-39 of human plasminogen kringle domains (13).
The peptides of the invention preferably range from 8 to 20 amino acids long. Peptides of the invention typically range from 7-20, more typically from 10-15 amino acids in length. The peptides are often about 10 amino acids in length. The peptides are more preferably 8, 9 or 10 residues long, most preferably 10 residues long.
The peptides of the invention may contain a single cysteine residue. In such a case, it is desirable that the cysteine residue be derivatized to block disulfide bond formation. Most preferably, peptides of the invention lack cysteine residues altogether.
The peptides also preferably contain a pair of proline residues. Each proline residue of the pair is preferably the residue penultimate to a terminus of a peptide, but either or both of the proline residues can be a terminal residue. Imino acids similar to proline, in that their side chains form a ring containing the peptide bonding nitrogen and a-carbon, and that will “break” an α-helix or β-sheet secondary structure, can be substituted for one or more of the proline residues. Exemplary peptides are shown as SEQ ID NOS: 1-50. The more preferred peptides are those of SEQ ID NOS: 1-3, 11, 12, 29-33, 35-38, 40, 41, and 44-50.
The peptides of the invention are active in inhibiting angiogenesis in the in vitro bovine aorta endothelial (BAE) cell proliferation assay with an IC 50 of 20 μM or less, preferably 5 μM or less, more preferably 1 μM or less and most preferably below 0.1 μM. Much preferred peptides of the invention are active in the in vitro BAE cell proliferation assay with an IC 50 of about 20 pM.
Alternatively, preferred peptides of the invention will exhibit inhibition of angiogenesis in a chick chorioallantoic membrane assay of at least 30% (i.e. inhibition is observed under at least 3 of 10 coverslips applied) at a dose of 50 μg/coverslip. More preferably at least 50% inhibition is observed at a dose of 25 μg/coverslip. Most preferably, inhibition in the range of 50-80% is observed for a dose ranging from 10-25 μg/coverslip.
Also, the peptides of the invention encompass peptides that have been derivatized, for example to improve transport across membranes by attachment of hydrophobic groups or that are carboxy-terminal amidated to improve resistance to serum proteases. Methods for accomplishing such derivatizations are known in the art.
Formulation of the peptides for administration is standard in the art. It is anticipated that optimization of formulation, dosages and schedule of administration is also standard in the art. Reference 16, especially at parts 4, 5 and 7, provides guidance in these matters. Administration of the peptides for anti-tumor treatment can be by any route, preferably oral, intravenous, intradermal, subcutaneous or aerosol. It is expected that subcutaneous administration is especially effective when anti-metastatic activity is desired (see, reference 6).
The dosage of the peptides will depend upon the therapeutic index of the compound. It is noted that angiostatin has been administered to mice in amounts of 100 mg/kg/day without observable toxicity. Inhibition of metastasis by angiostatin is observed at doses of about 1 mg/kg/day and inhibition of primary tumor growth is observed at about 10 mg/kg/day (6). Thus, it is expected that effective doses of the peptides of the present invention will be about 0.2 μg/kg/day to about 2 mg/kg/day for inhibition of metastasis. Preferred dosages are in the 2-200 μg/kg/day range, most preferred dosages are in the 20-50 μg/kg/day range. It is expected that the dosage ranges will be about 10-fold higher for inhibition of primary tumor growth.
EXAMPLE 1
Anti-proliferative Activity of Peptides Derived from Angiostatin
The peptides were tested in an in vitro bovine aorta endothelial cell (BAE) proliferation assay for their ability to inhibit BAE cell proliferation. Cells were plated into 24-well culture plates at 1.25×10 4 cells/well in complete SFM-endothelial medium (Gibco, USA). After 24 h, the medium was removed and various amounts of peptides were added into the wells in 0.5 ml of SFM-endothelial medium without bFGF. After 30 minutes incubation, bFGF was added into each well at a final concentration of 1 ng/ml together with another 0.5 ml of SFM-endothelial medium. Seventy-two hours later, cells were trypsinized and counted using a hemocytometer. Commercial E. coli recombinant human angiostatin (1 μM) was used as a control in the experiments.
Peptides Angio-2, Angio-3 and Angio-4, containing sequences from kringles 2, 3 and 4 of human plasminogen (SEQ ID NOS: 2, 3, and 11), all inhibited BAE cell proliferation in a dose-dependent manner ( FIGS. 1 , 2 and 3 ). The IC 50 of the three peptides are about 2 mM, 20 nM and 200 uM respectively. It is noted that peptide Angio-3 inhibited BAE cell proliferation with an IC 50 in a range similar to the reported nanomolar range of angiostatin protein (5). In contrast, a randomly scrambled version of Angio-3 (Angio-3S) in which the same amino acids present in Angio-3 were put in a random order, completely lost angiogenesis inhibition ability ( FIG. 1 ). This indicates that the antiangiogenic activity of the peptides are sequence dependent. No obvious cell cytotoxicity was observed by peptide angio-3 at 20 μM with BAE cells analyzed by trypan blue staining and microscopic cellular morphology analysis.
The BAE inhibition assay provides a method for determining the anti-angiogenic activity of peptides. For example, peptides Angio-3A, -3B, -3C, -3D, -3E and -3F (SEQ ID NOS: 4-9) are peptides in which the six amino acids surrounded by the two prolines are individually mutated into alanine. The contribution of each of the six amino acids between the proline residues to the biological activity of Angio-3 can be determined by testing these peptides.
EXAMPLE 2
Anti-angiogenic Activity of Peptides Derived from Angiostatin
Since peptides Angio-2, Angio-3 and Angio-4 all inhibited BAE cell proliferation, they were also tested in the chick embryo chorioallantoic membrane (CAM) in vivo angiogenesis assay (7). In this assay, the peptides are coated onto 2-3 mm glass squares cut from microscope cover slips. All three peptides inhibited chick CAM angiogenesis ( FIGS. 4 , 5 and 6 ). Peptide Angio-3 reduced microvessel density at the very low dose of 12 pg/cover slip (the lowest dose tested, comparing to a PBS control). As a positive control, recombinant angiostatin at the dose of 100 ug/cover slip was tested in the same experiment. The amount of inhibition (judging from the extent of reduction in microvessel density) from 100 ug recombinant angiostatin is equivalent to 1.2 ug of Angio-3 peptide. Based on this, we estimated that Angio-3 is at least as potent as angiostatin in inhibiting chick CAM angiogenesis.
At high doses, e.g., 1 mg/cover slip, the blood vessels under the cover slip containing all three peptides died and circulation was stopped. The color of the blood changed into dark red instead of the bright red of the circulating blood.
The above data demonstrated that Angio-2, Angio-3 and Angio-4, small peptides derived from the sequence of human plasminogen kringle domains 2, 3 and 4 function as potent angiogenesis inhibitors. Importantly, peptide Angio-3 is more potent in inhibiting BAE cell proliferation compared to angiostatin protein and at least as potent as recombinant angiostatin in inhibiting chick CAM angiogenesis.
Cao et al. (12) show that integrity of complete kringle domains is required for anti-angiogenic activity of angiostatin and that a tandem pair of properly folded domains is necessary. Cao et al. (13) also show that, at least with respect to the k5 domain, appropriate disulfide bond formation is necessary for maintaining anti-angiogenic activity. Thus, it is surprising that the exemplified small peptides of the invention, which (1) do not form complete kringle domains and (2) do not contain any cysteine residues and therefore do not form disulfide bonds, have such high activity.
EXAMPLE 3
Antiangiogenic Activity of Peptides Derived from Endostatin, VEGF and VEGF Receptors
Peptides were tested in an in vitro bovine aorta endothelial cell (BAE) proliferation assay for their ability to inhibit BAE cell proliferation. Cells were plated into 24-well culture plates at the number of 1.25×10 4 /well in complete SFM-endothelial media (Gibco, USA). After 24 hours, the medium was removed and various amounts of peptides were added into the wells in 0.5 ml of SFM-endothelial medium without bFGF. After 30 minutes incubation, bFGF was added into each well at a final concentration of 1 ng/ml together with another 0.5 ml of SFM-endothelial medium. Seventy-two hours later, cells were trypsinized and counted using a hemocytometer. Peptides Endo-2, Endo-3 and Endo-4 all inhibited BAE cell proliferation in a dose-dependent manner while peptide Endo-1 has only a slight inhibition effect at high doses ( FIG. 7 ). The IC 50 of the Endo-2, -3 and -4 peptides is estimated to be 0.4 uM, 0.3 uM and 2 uM respectively.
All 4 endostatin-derived peptides were also tested in the chick embryo chorioallantoic membrane (CAM) in vivo angiogenesis assay. These peptides reduced microvessel density with various efficacy comparing to a PBS control ( FIG. 8 ).
Peptides designed from mammalian VEGF sequences (mVEGF) and Zebrafish VEGF (fVEGF) showed dose-dependent inhibition of CAM angiogenesis (FIGS. 9 , 10 ). Scrambled mutant peptide where the same amino acids in mVEGF were placed in a random order completely destroyed the angiogenesis inhibition activity of mVEGF peptide.
Two small peptides, hFLT1 and hFLT2, were designed from the second immunoglobulin domain (Ig domain 2) of the extracellular region of FLT-1. The peptide hFLT2 showed very potent angiogenesis inhibition activity on CAM ( FIGS. 10 and 11 ). Surprisingly, a truncated version of hFLT2 peptide, hFLT2-11, in which the N-terminal two amino acids have been deleted, showed a even more potent antiangiogenic activity comparing to hFLT2 ( FIG. 11 ). However, a single amino acid mutated version of the same peptide, hFLT2-T, in which the second amino acid proline was replaced with threonine, has a much weaker antiangiogenic activity ( FIG. 11 ). Peptide hFLT2-9 in which four amino acids were removed from the N-terminal of hFLT2, showed similar level of antiangiogenic activity as the original peptide ( FIG. 11 ). Further truncation at the N-terminal of the peptide resulted in non-functional peptide (hFLT2-7 and hFLT2-5).
The above data demonstrated that small peptides derived from the sequence of human endostatin, VEGF and FLT-1 can function as potent angiogenesis inhibitors.
EXAMPLE 4
Inhibition of Endothelial Cell Proliferation and Retardation of Tumor Growth in Mice
Mouse Tumor Assays
Human hepatoma cell line HepG2 was cultured and 1 million cells were injected subcutaneously into the right back of each 6 weeks old BALB/c nude mouse. Visible tumors appear from about 2 weeks after tumor cell injection. Mice with tumors were then randomly grouped and injected with the peptide at 300 μg/mouse every 12 h (16-19 g average weight). No obvious toxicity was observed at this dose. Tumor sizes were measured with a caliper every three days and volumes calculated using the formula (width) 2 ×length×0.52. Statistical analyses were done using student t-test using the SigmaStat software (SPSS, USA).
Peptide Angio-3 Inhibits Tumor Growth in Nude Mouse
Tumors are angiogenesis dependent. To test if peptide angio-3 can inhibit tumor growth in vivo, human hepatoma HepG2 cells were injected subcutaneously into nude mice to induce tumor formation. Tumor nodules appear in about 15-18 days after tumor cell injection. Peptide was then injected at a distant site from the tumor into tumor bearing mice at 15 mg/kg every 12 h for up to a month. As shown in FIG. 12 , injection of peptide Angio-3 inhibited HepG2 tumor growth by about 40% at the time of experimental termination. Experiments were terminated when the control group tumors started to show necrosis. Statistical analysis indicates that the tumor size difference between the treatment and control groups is significant at p<0.1.
In summary, this Example demonstrates that angio-3 can inhibit endothelial cell proliferation and retard tumor growth in mice.
REFERENCES
The following articles of the periodical and patent literature are cited above. Each text is hereby incorporated in its entirety by reference by such citation.
1. Folkman, J. et al., Cell 87, 1153-1155, 1996 and U.S. Pat. No. 5,639,735. 2. Folkman, J. et al., J. Nature Medicine 1, 27-31, 1995. 3. Kim, K. J. et al., Nature 362, 841-844, 1993. 4. Auerbach, W. et al., Pharmac. Ther. 63, 265-311, 1994. 5. O'Reilly, M. S. et al., Cell 79, 315-328, 1994. 6. O'Reilly, M. S. et al., Nature Medicine 2, 689-692, 1996. 7. O'Reilly, M. S. et al., Cell 88, 277-285, 1997. 8. Boehm, T. et al., Nature 390, 404-407, 1997. 9. Kerbel, R. S., Nature 390, 335-336, 1997. 10. Handin, R. I. et al., Chapter 58 of “Heart Diseases: A Textbook Of Cardiovascular Medicine,” 4 th ed. c. 1992 by W. B. Saunders Company, pp. 1767-1789. 11. O'Reilly, M. S. et al. U.S. Pat. No. 5,639,725, 1997. 12. Cao, Y. et al., J. Biol. Chem. 271, 29461-29467, 1996. 13. Cao, Y. et al., J. Biol. Chem. 272, 22924-22928, 1997. 14. Kini, R. M. et al., Curr. Topic Peptides & Prot. Res. 1, 297-311, 1994. 15. Kini, R. M. et al., Biochem. Biophy. Res. Comm. 212, 1115-1124, 1995. 16. “Remington: The Science and Practice of Pharmacy”, 19 th ed., c. 1995 by the Philadelphia College of Pharmacy and Science. 17. Oh, S. P. et al., PNAS USA 91, 4229-4233, 1994. 18. Rehn, M. et al., PNAS USA 91, 4234-4238, 1994. 19. Muragaki, Y. et al., PNAS USA 92, 8763-8767, 1995. 20. Ding, Y-H et al., PNAS USA 95, 10443-10448, 1998. 21. Boehm, T. et al., Biochem. Biophy. Res. Comm. 252, 190-194, 1998. 22. Ferrara, N. et al., Endo. Rev. 18, 4-25, 1997. 23. Keyt, B. A. et al., J. Biol. Chem. 271, 5638-5646, 1996. 24. Muller, Y. A. et al., PNAS USA 94, 7194-7197, 1997. 25. Muller, Y. A. et al., Structure 5, 1325-1338, 1997. 26. Weismann, C. et al., Cell 91, 695-704, 1997. 27. Barleon, B. et al,. J. Biol. Chem. 272, 10382-10388, 1997. 28. Cunningham, S. A. et al., Biochem. Biophy. Res. Comm. 231, 569-599, 1997. 29. Millauer, B. et al., Nature 367, 576-579, 1994. 30. Kong, H. et al., Human Gene Therapy 9, 823-833, 1998. 31. Risau, W. Mechanisms of angiogenesis. Nature 1997; 386: 671-674. 32. Ji, W-R., Barrientos, L. G., Llinas, M., Gray, H., Villarreal, X., Deford, M. E., Castellino, F. J., Kramer, R. A and Trail, P. A. Selective inhibition by kringle 5 of human plasminogen on endothelial cell migration, an important process in angiogenesis. Biochem. Biophys. Res. Commun. 1998; 247: 414-419. 33. Lu, H., Dhanabal, M., Volk, R., Waterman, M. J., Ramchandran, R., Knebelmann, B., Segal, M and Sukhatme, V. P. Biochem. Biophys. Res. Commun. 1999; 258: 668-673. | The present invention provides peptides having potent anti-angiogenic activity and endothelial cell proliferation inhibition activity. The peptides can be administered as pharmaceutical compositions for prevention or treatment of undesired angiogenesis, for instance for prevention of tumor metastasis or inhibition of primary tumor growth. | 2 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a dielectric ceramic composition to be used in the frequency region of microwaves.
2. Description of the Prior Art
As the communications method utilizing electromagnetic waves in the frequency region of microwaves has been progressed in past years, for example, in the automobile telephones, portable phones or satellite communications, etc., miniaturization of the apparatus is strongly required. That is, miniaturization of each components constituting the apparatus is demanded. A dielectric material is incorporated in a filter or an oscillator of the apparatus as a dielectric resonator. The size of the dielectric resonator is inversely proportional to a square root of the dielectric constant of the dielectric material when same resonant mode is used, and therefore a dielectric material with a high dielectric constant becomes necessary in order to a compact size dielectric resonator is realized. Besides, the loss of the dielectric material against microwaves should be small, i.e., the dielectric material should have a high Q factor, with a small temperature change of the resonant frequency so that the dielectric material is applied to an actual resonator.
Many ceramic compositions have ever been developed for use in the dielectric resonator. In these compositions BAO-TiO02-SM203 type has been disclosed as a ceramic compositions of a particularly high dielectric constant in U.S. Pat. No. 4,330,631 dated May 18, 1982. This type of ceramic compositions assumes approximately 80 dielectric constant, and as high as about 3000 Q factor at 2-4 GHz, and a small temperature coefficient of the resonant frequency. Also, Ba-PbO-Ti02-Nd203 type has been reported in the Journal of American Ceramic Society, Vol. 67 (1984), p. 278-281 as a ceramic composition having a dielectric constant of not smaller than 90.
Not only the above-described types of ceramic compositions, but the conventional ceramic compositions of a high dielectric constant for microwave use have a high sintering temperature, namely, 1300° C. or so and are of mixed phase. Therefore, the microwave characteristics of the mass-produced ceramic composition are greatly varied and, manufacturing costs high.
SUMMARY OF THE INVENTION
The object of the present invention is therefore to provide a composition of ceramic composition having approximately the same high dielectric constant as the conventional microwave ceramic composition and a low sintering temperature.
In order to accomplish the above-described object, according to the present invention, a novel ceramic composition is provided, which is composed of lead oxide, calcium oxide, iron oxide, tantalum oxide and niobium oxide, and represented by (Pb 1-x Ca x ) 1+a {(Fe 1/2 (Ta 1-y Nb y ) 1/2 }) 3+a wherein x, y and a respectively satisfy:
0.44≦x≦0.63
0.0≦y≦1.0
0.0≦a≦0.08
The sintering temperature of the ceramic composition is 1150° C. or lower. Moreover, the ceramic composition has not smaller than 40 dielectric constant and not smaller than 500 Q factor in the 2-6 GHz microwave frequency, with not larger than 100 ppm/° C. absolute value of the temperature coefficient of the resonant frequency. (The ceramic composition forms perovskite-type single.)
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
As a starting material of a ceramic composition of the present invention, PbO, CaC03, Fe203, Ta205 and Nb205 with a chemically high purity are used. These materials are weighed into a variety of composition after the purity thereof is corrected. Powdered materials are put in a polyethylene ball mill. Balls of stabilized zirconia having 5 mm diameter and pure water are added to the materials and mixed for 17 hours. After the mixing, the slurry is dried, moved into an alumina crucible, and calcined for two hours at 800-950° C. The calcined powder is milled in the ball mill for 17 hours. Thereafter, the slurry is dried thereby to obtain a powder material. 5% solution of polyvinyl alcohol is added as a binder to the powder material by 6 wt. % and granulated through a 32-mesh screen, subsequently pressed with 100 Mpa into the configuration of a cylinder having 13 mm diameter and about 5 mm thickness. After the pressed body is heated for two hours at 600° C. to burn out the binder, the body is placed into a magnesia vessel along with the calcined powders of the same composition so as to prevent evaporation of PbO. The vessel is capped and is sintered for two hours at 1000-1200° C. The dielectric characteristic for the microwaves of the sintered body which has been sintered at the temperature to assume the maximum density is measured. The resonant frequency and Q factor are detected according to a dielectric resonator method. Moreover, the dielectric constant is calculated from the size and resonant frequency of the sintered body. The resonant frequency is 2-6 GHz. The temperature coefficient (τf) is calculated by the method of least squares after measuring the resonant frequencies at -25° C., 20° C. and 85° C. The results are shown in Table 1 below.
TABLE 1______________________________________Composition S.T. τfNo. x y a °C. ε Q ppm/°C.______________________________________ 1* 0.42 1.0 0.0 1150 152 770 +111 2* 0.42 0.0 0.0 1050 109 410 +141 3 0.44 1.0 0.0 1150 141 880 +91 4 0.44 0.0 0.0 1050 95 530 +100 5 0.48 1.0 0.0 1150 121 1110 +56 6 0.48 0.9 0.0 1150 117 1100 +51 7 0.48 0.5 0.0 1100 92 870 +39 8 0.48 0.2 0.0 1100 85 620 +35 9 0.48 0.0 0.0 1050 77 590 +3310* 0.5 1.0 -0.02 1200 115 210 +4111 0.5 1.0 0.0 1150 113 1230 +3812 0.5 1.0 0.03 1100 111 1200 +3713 1.0 1.0 0.08 1100 107 1020 +3014* 0.5 1.0 0.1 1050 99 490 +2315* 0.5 0.0 -0.02 1100 62 110 -1716 0.53 0.0 0.0 1050 60 670 -2117 0.53 0.0 0.03 1050 58 660 -2218 0.53 0.0 0.08 1050 55 530 -1719* 0.53 0.0 0.1 1050 51 330 -1220 0.53 0.5 0.0 1100 77 1000 +121 0.56 1.0 0.0 1150 92 1450 +722 0.63 1.0 0.0 1150 70 2090 -1423 0.63 0.5 0.0 1100 55 1410 -3624 0.63 0.0 0.0 1100 40 820 .increment.5925* 0.65 0.0 0.0 1100 36 S30 -72______________________________________ S.T.: sintering temperature
The asterisk refers to a comparative example out of the range of the invention.
As is apparent from Table 1, the ceramic composition in the claimed region results in the characteristics of 40 or higher dielectric constant, 500 or higher Q factor and 100 ppm/° C. or lower absolute value of the temperature coefficient of the resonant frequency.
On the other hand, if x in the composition formula is smaller than 0.44, the dielectric constant becomes higher, but the temperature coefficient of the resonant frequency exceeds 100 ppm/° C. If x in the composition formula becomes larger than 0.63, the dielectric constant is decreased to 40 or lower. Moreover, when a in the composition formula is negative or exceeds 0.08, the Q factor is not larger than 500. Therefore, the ceramic composition outside the claim is not practically useful as a dielectric material for use in the frequency region of microwaves. If y in the composition formula is increased, that is, Ta is substituted with Nb, the dielectric constant and Q factor are raised, but the sintering temperature becomes higher. Particularly, according to the composition No. 21 in Table 1, the dielectric constant is 90 or higher and the Q factor is 1000 or higher, and moreover the absolute value of the temperature coefficient of the resonant frequency shows not larger than 10 ppm/° C. The ceramics of the composition No. 21 has superior microwave dielectric characteristics.
As is made clear from the foregoing description, the dielectric ceramic composition of the present invention is composed of lead oxide, calcium oxide, iron oxide, tantalum oxide and niobium oxide, representing remarkable dielectric characteristics in the frequency region of the microwaves. Especially, the sintering temperature of the ceramic composition is low, specifically, 1150° C. or lower, with forming perovskite-type single phase. Accordingly, the characteristics of the ceramic composition during the mass production can be restrained from varying and the manufacturing cost can be reduced. Further, the dielectric ceramic composition embodied by the present invention is applicable not only to a dielectric resonator, but to a circuit substrate for microwaves. In other words, the dielectric ceramic composition of the present invention is of high practical use in industry.
The ceramic composition may contain oxides of the other elements than within the scope of the invention so long as they do not make adverse effects to the dielectric characteristics of the ceramic composition.
Although the present invention has been fully described in connection with the preferred embodiment thereof with reference to the accompanying drawings, it is to be noted that various changes and modifications are apparent to those skilled in the art. Such changes and modifications are to be understood as included within the scope of the present invention as defined by the appended claim unless they depart therefrom. | The present invention provides a composition of dielectric ceramic composition to be used in the frequency region of microwaves.
The composition contains lead oxide, calcium oxide, iron, oxide, tantalum oxide and niobium oxide, and is represented by (Pb 1-x Ca x ) 1+a {Fe 178 (Ta 1-y Nb y ) 178 }O 3+a wherein x, y and a satisfy, respectively, 0.44≦x≦0.63, 0.0≦y≦1.0 and 0.0≦a≦0.08. | 7 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The invention relates to a semiconductor light-emitting device and method of fabricating the same, and more particularly, to a ZnO-based semiconductor light-emitting device and method of fabricating the same.
[0003] 2. Description of the Prior Art
[0004] Light-emitting diodes (LEDs) are semiconductor devices initially used for indicator lamps or display panels. As the emergence of white light LEDs, LEDs can also be used for illumination. Comparing with traditional light sources, LEDs have the advantages of high efficiency, long lifetime, high durability and high reliability, etc. It is renowned as revolutionary light source of the 21st century.
[0005] Zinc oxide (ZnO) is a II-VI group compound semiconductor with a direct bandgap energy of 3.37 eV at room temperature, and its emitted light is in the range of ultraviolet.
[0006] As a raw material for fabricating white light LEDs, the zinc oxide has following advantages:
[0007] 1. Abundance and relatively low cost of raw materials.
[0008] 2. The exciton binding energy of zinc oxide is up to 60 meV, so the light emitting efficiency is high.
[0009] 3. Since the emission wavelength of zinc oxide is around 380 nm, it is more efficient in exciting fluorescent material than other materials (e.g. GaN) for fabricating white light LEDs. Therefore, the zinc oxide is very suitable for fabricating white light LEDs.
[0010] 4. Zinc oxide is easier to be processed by chemical etching than other materials (e.g. GaN) for fabricating white light LEDs.
[0011] However, zinc oxide shows intrinsic n-type characteristics due to the presence of native defects, such as oxygen vacancies and zinc interstitials. Thus it suffers from the difficulty to prepare reliable and high-quality p-type zinc oxide. In order to realize a high-quality p-type zinc oxide, high-concentration p-type doping is needed to overcome the strong self-compensation effect resulting from the native n-type defects. Nevertheless, the solid solubility of p-type acceptors in zinc oxide is not high enough to achieve high p-type doping concentrations. Therefore, it is difficult to produce high-quality p-type zinc oxide, as well as the important structure of an LED, the p-n junction. As a result, a reliable growth technique is desired for the growth of high-quality zinc oxide.
[0012] Though zinc oxide is suitable for fabricating a white light LED, but owing to the limitations described above, the technology of fabricating a white light LED with zinc oxide is held up.
[0013] Accordingly, a scope of the invention is to provide a zinc-oxide-based semiconductor light-emitting device and a method of fabricating the same to solve aforesaid problems.
SUMMARY OF THE INVENTION
[0014] A scope of the invention is to provide a zinc-oxide-based semiconductor light-emitting device and a method of fabricating the same.
[0015] According to an embodiment of the invention, the method of fabricating a semiconductor light-emitting device, firstly, prepares a substrate. Then, by an atomic layer deposition based process, the method forms a ZnO-based multi-layer structure on or over the substrate, where the ZnO-based multi-layer structure includes a light-emitting region.
[0016] According to another embodiment of the invention, the semiconductor light-emitting device includes a substrate and a ZnO-based multi-layer structure formed on or over the substrate, where the ZnO-based multi-layer structure includes a light-emitting region.
[0017] Therefore, according to the invention, the method fabricates a semiconductor light-emitting device by an atomic layer deposition based process. Thereby, the method can successfully fabricate high-quality ZnO-based semiconductor light-emitting device. In addition, since the layer formed by the atomic layer deposition process has several advantages such as easy and accurate thickness control, accurate control of material composition, facile doping, abrupt interfaces, high uniformity over a large area, good reproducibility, dense and pinhole-free structures, low deposition temperatures, etc., the semiconductor light-emitting device has very high crystal quality and very low defect density.
[0018] The advantage and spirit of the invention may be understood by the following recitations together with the appended drawings.
BRIEF DESCRIPTION OF THE APPENDED DRAWINGS
[0019] FIG. 1 shows the fabricating method according to an embodiment of the invention.
[0020] FIG. 2 shows the X-ray diffraction pattern of the ZnO layer grown on a sapphire substrate by an atomic layer deposition process.
[0021] FIG. 3 shows the spontaneous emission photoluminescence spectrum of the ZnO layer grown on a sapphire substrate by an atomic layer deposition process.
[0022] FIG. 4 shows the stimulated emission photoluminescence spectra of the ZnO layer grown on a sapphire substrate by an atomic layer deposition process.
[0023] FIG. 5 shows the relationship between the photoluminescence light emission intensity and the excitation intensity of the ZnO layer grown on a sapphire substrate by an atomic layer deposition process.
[0024] FIG. 6 shows a semiconductor light-emitting device according to an embodiment of the invention.
[0025] FIG. 7 shows the current density vs. voltage characteristics of the semiconductor light-emitting device shown in FIG. 6 .
[0026] FIG. 8 shows the X-ray diffraction patterns of the ZnO layer and the GaN layer of the semiconductor light-emitting device shown in FIG. 6 .
[0027] FIG. 9 shows the photoluminescence spectra of the ZnO layer and the GaN layer of the semiconductor light-emitting device shown in FIG. 6 .
[0028] FIG. 10 shows the electroluminescence spectra of the semiconductor light-emitting device shown in FIG. 6 at various injection currents.
DETAILED DESCRIPTION OF THE INVENTION
[0029] Please refer to FIG. 1 . FIG. 1 shows the fabricating method according to an embodiment of the invention. According to the embodiment of the invention, the method fabricates a ZnO-based semiconductor light-emitting device by an atomic layer deposition based process. The ZnO-based semiconductor light-emitting device means that the semiconductor light-emitting device has, but not limited to, a ZnO layer, a MgxZn 1-x O layer, a BeyZn 1-y O layer, or other compound layer with ZnO.
[0030] As shown in FIG. 1 . The method, firstly, prepares a substrate 10 and set the substrate 10 in a reaction chamber 20 designed for performing an atomic layer deposition (ALD) based process. In the embodiment, the substrate 10 can be a sapphire substrate, a Si substrate, a SiC substrate, a GaN substrate, AlGaN substrate, a InGaN substrate, a ZnO substrate, a ScAlMgO 4 substrate, a YSZ (yttria-stabilized zirconia) substrate, a SrCu 2 O 2 substrate, a CuAlO 2 substrate, LaCuOS substrate, a NiO substrate, a LiGaO 2 substrate, a LiAlO 2 substrate, a GaAs substrate, a glass substrate, or the like.
[0031] Then, by an atomic layer deposition based process, the method forms a ZnO-based multi-layer structure on or over the substrate, where the ZnO-based multi-layer structure includes a light-emitting region (not shown). In actual applications, the atomic layer deposition based process can be an atomic layer deposition process, a plasma-enhanced atomic layer deposition process, a plasma-assisted atomic layer deposition process, or combination of above processes, such as combination of the atomic layer deposition process and the plasma-enhanced atomic layer deposition process or combination of the atomic layer deposition process and the plasma-assisted atomic layer deposition process. Using the plasma-enhanced ALD process or the plasma-assisted ALD process can ionize precursors, so as to lower the deposition temperature. It is noticeable that the atomic layer deposition process is also named as Atomic Layer Epitaxy (ALE) process or Atomic Layer Chemical Vapor Deposition (ALCVD) process, so that these processes are actually the same.
[0032] In the embodiment, the light-emitting region can be a p-type doped ZnO/intrinsic ZnO/n-type doped ZnO structure combination, a p-type doped ZnO/intrinsic ZnO structure combination, a p-type doped ZnO/n-type doped ZnO structure combination, a p-type doped Mg x Zn 1-x O/intrinsic Mg y Zn 1-y O/n-type doped Mg z Zn 1-z O structure combination, a p-type doped Mg x Zn 1-x O/n-type doped Mg y Zn 1-y O/n-type doped Mg z Zn 1-z O structure combination, a p-type doped Mg x Zn 1-x O/p-type doped Mg y Zn 1-y O/n-type doped Mg z Zn 1-z O structure combination, a p-type doped Mg x Zn 1-x O/intrinsic ZnO/n-type doped Mg z Zn 1-z O structure combination, a p-type doped Mg x Zn 1-x O/n-type doped ZnO/n-type doped Mg z n 1-z O structure combination, a p-type doped Mg x Zn 1-x O/p-type doped ZnO/n-type doped Mg z Zn 1-z O structure combination, a p-type doped Mg x Zn 1-x O/n-type doped Mg z Zn 1-z O structure combination, a p-type doped Mg x Zn 1-x O/intrinsic Mg y Zn 1-y O structure combination, a p-type doped Mg x ZnO/intrinsic ZnO structure combination, a p-type doped Mg x Zn 1-x O/intrinsic ZnO/n-type doped ZnO structure combination, a p-type doped Mg x Zn 1-x O/p-type doped ZnO/n-type doped ZnO structure combination, a p-type doped Mg x Zn 1-x O/n-type doped ZnO structure combination, a p-type doped ZnO/intrinsic ZnO/n-type doped Mg z Zn 1-z O structure combination, a p-type doped ZnO/n-type doped ZnO/n-type doped Mg z Zn 1-z O structure combination, a p-type doped ZnO/n-type doped Mg z Zn 1-z O structure combination, an n-type doped ZnO/p-type doped the substrate structure combination, an n-type doped Mg z Zn 1-z O/p-type doped the substrate structure combination, a p-type doped Be x Zn 1-x O/intrinsic Be y Zn 1-y O/n-type doped Be z Zn 1-z O structure combination, a p-type doped Be x Zn 1-x O/n-type doped Be y Zn 1-y O/n-type doped Be z Zn 1-z O structure combination, a p-type doped Be x Zn 1-x O/p-type doped Be y Zn 1-y O/n-type doped Be z Zn 1-z O structure combination, a p-type doped Be x Zn 1-x O/intrinsic ZnO/n-type doped Be z Zn 1-z O structure combination, a p-type doped Be x Zn 1-x O/n-type doped ZnO/n-type doped Be z Zn 1-z O structure combination, a p-type doped Be x Zn 1-x O/p-type doped ZnO/n-type doped Be z Zn 1-z O structure combination, a p-type doped Be x Zn 1-x O/n-type doped Be z Zn 1-z O structure combination, a p-type doped Be x Zn 1-x O/intrinsic Be y Zn 1-y O structure combination, a p-type doped Be x Zn 1-x O/intrinsic ZnO structure combination, a p-type doped Be x Zn 1-x O/intrinsic ZnO/n-type doped ZnO structure combination, a p-type doped Be x Zn 1-x O/p-type doped ZnO/n-type doped ZnO structure combination, a p-type doped Be x Zn 1-x O/n-type doped ZnO structure combination, a p-type doped ZnO/intrinsic ZnO/n-type doped Be z Zn 1-z O structure combination, a p-type doped ZnO/n-type doped ZnO/n-type doped Be z Zn 1-z O structure combination, a p-type doped ZnO/n-type doped Be z Zn 1-z O structure combination, an n-type doped Be z Zn 1-z O/p-type doped the substrate structure combination, or the like, 0<x, y, z≦1, where the p-type doped the substrate can be the substrate 10 .
[0033] The precursors of the ZnO structure can be a DEZn (diethylzinc, Zn(C 2 H 5 ) 2 ) precursor, a DMZn (dimethylzinc, Zn(CH 3 ) 2 ) precursor, a zinc acetate (Zn(CH 3 COO) 2 ) precursor or a ZnCl 2 precursor and a H 2 O precursor, an O 3 precursor, an O 2 precursor, or an oxygen radical. The DEZn, the DMZn, the zinc acetate or the ZnCl 2 is the source of the Zn, and the H 2 O, the O 3 , the O 2 , or the oxygen radical is the source of the O. The precursors of the Mg x Zn 1-x O structure can be a DEZn precursor, a DMZn precursor, a zinc acetate precursor or a ZnCl 2 precursor, a MgCp 2 (Bis(cyclopentadienyl)magnesium, Mg(C 5 H 5 ) 2 ) precursor, a Mg(thd) 2 (2,2,6,6-tetramethyl-heptanedionato-3,5-magnesium(II)) precursor or a Bis(pentamethylcyclopentadienyl)magnesium (C 20 H 30 Mg) precursor and a H 2 O precursor, an O 3 precursor, an O 2 precursor, or an oxygen radical. The DEZn, the DMZn, the zinc acetate or the ZnCl 2 is the source of the Zn; the MgCp 2 , the Mg(thd) 2 or the Bis(pentamethylcyclopentadienyl)magnesium is the source of the Mg; and the H 2 O, the O 3 , the O 2 , or the oxygen radical is the source of the O.
[0034] The precursors of the Be x Zn 1-x O structure can be a DEZn precursor, a DMZn precursor, a zinc acetate precursor or a ZnCl 2 precursor, a Be(acac) 3 (beryllium acetylacetonate, (CH 3 COCH═C(O—)CH 3 ) 2 Be) precursor or a BeCl 2 precursor and a H 2 O precursor, an O 3 precursor, an O 2 precursor, or an oxygen radical. The DEZn, the DMZn, the zinc acetate or the ZnCl 2 is the source of the Zn; the Be(acac) 3 or the BeCl 2 is the source of the Be; and the H 2 O, the O 3 , the O 2 , or the oxygen radical is the source of the
[0035] In the embodiment, the method of fabricating the p-type doped ZnO includes adding a p-type dopant during the atomic layer deposition process, where the p-type dopant can be nitrogen, phosphorous, arsenic, etc. The precursor of nitrogen as the p-type dopant is, preferable but not limited to, a NH 3 precursor, a NO precursor, a N 2 O precursor, an 1,1-Dimethylhydrazine ((CH 3 ) 2 NNH 2 ) precursor, a Tert-butylamine ((CH 3 ) 3 CNH 2 ), or a Tert-butyl hydrazine ((CH 3 ) 3 CNHNH 2 ) precursor. The precursor of phosphorous as the p-type dopant is, preferable but not limited to, a PH 3 precursor, a P 2 O 5 precursor, a Zn 3 P 2 precursor, or a Diethyl phosphite ((C 2 H 5 O) 2 P(O)H). The precursor of arsenic as the p-type dopant is, preferable but not limited to, an AsH 3 precursor.
[0036] In the embodiment, the method of fabricating the n-type doped ZnO includes adding an n-type dopant during the atomic layer deposition process, where the n-type dopant can be aluminum, gallium, indium, etc. The precursor of aluminum as the n-type dopant is, preferable but not limited to, a Trimethylaluminum (Al(CH 3 ) 3 ) precursor or a Triethylaluminum (Al(C 2 H 5 ) 3 ) precursor. The precursor of gallium as the n-type dopant is, preferable but not limited to, a Trimethylgallium (Ga(CH 3 ) 3 ) precursor or a Triethylgallium (Ga(C 2 H 5 ) 3 ) precursor. The precursor of indium as the n-type dopant is, preferable but not limited to, a Indium acetylacetonate (In(OCCH 3 CHOCCH 3 ) 3 ) precursor or a Trimethylindium (In(CH 3 ) 3 ) precursor.
[0037] As shown in FIG. 1 , an example of forming a ZnO layer by an atomic layer deposition process is presented. In an embodiment, an atomic layer deposition cycle (ALD cycle) includes four reaction steps of:
[0038] 1. Using a carrier gas 22 to carry DEZn molecules 24 into the reaction chamber 20 ; thereby, the DEZn molecules 24 are absorbed on the surface of the substrate 10 to form a layer of DEZn.
[0039] 2. Using the carrier gas 22 , with assistance of the pump 28 , to purge the DEZn molecules which are not absorbed on the surface of the substrate 10 .
[0040] 3. Using the carrier gas 22 to carry H 2 O molecules 26 into the reaction chamber 20 ; thereby, the H 2 O molecules 26 react with the DEZn radicals absorbed on the surface of the substrate 10 to form one monolayer of ZnO, where by-product are organic molecules.
[0041] 4. Using the carrier gas 22 , with assistance of the pump 28 , to purge the residual H 2 O molecules 26 and the by-product due to the reaction.
[0042] In the embodiment, the carrier gas 22 can be highly pure argon gas or nitrogen gas. The above four steps is called an ALD cycle. An ALD cycle grows a thin film with a thickness of only one monolayer on the entire surface of the substrate 10 ; the characteristic is named as “self-limiting”, and the characteristic allows the precision of the thickness control of the atomic layer deposition to be one monolayer. Therefore, the thickness of the ZnO layer can be precisely controlled by the number of ALD cycles.
[0043] In practice, during the process of fabricating an n-type doped ZnO or a p-type doped ZnO, the doping is implemented by replacing partial ALD cycles with the ALD cycles of n-type dopant or p-type dopant, and the doping concentration is determined by the proportion of the replaced ALD cycles. Take an n-type doped ZnO with 6% Al for example, 3 of 50 ALD cycles of DEZn and H 2 O are replaced by 3 ALD cycles of TMA and H 2 O, or 6 of 100 ALD cycles of DEZn and H 2 O are replaced by 6 ALD cycles of TMA and H 2 O, etc.
[0044] In the embodiment, the deposition temperature is in a range of from room temperature to 800° C. However, the deposition temperature is preferably in a range of from 100° C. to 300° C. It is noticeable that since the deposition temperature is relatively low, the damage and/or malfunction probability of equipment owing to high temperature can be reduced, and the reliability of the process and the equipment availability are further enhanced.
[0045] In order to further decrease the defect density and improve the crystal quality, any structure of the p-type doped ZnO/intrinsic ZnO/n-type doped ZnO structure combination, the p-type doped ZnO/intrinsic ZnO structure combination, the p-type doped ZnO/n-type doped ZnO structure combination, the p-type doped Mg x Zn 1-x O/intrinsic Mg y Zn 1-y O/n-type doped Mg z Zn 1-z O structure combination, the p-type doped Mg x Zn 1-x O/n-type doped Mg y Zn 1-y O/n-type doped Mg z Zn 1-z O structure combination, the p-type doped Mg x Zn 1-x O/p-type doped Mg y Zn 1-y O/n-type doped Mg z Zn 1-z O structure combination, the p-type doped Mg x Zn 1-x O/intrinsic ZnO/n-type doped Mg z Zn 1-z O structure combination, the p-type doped Mg x Zn 1-x O/n-type doped ZnO/n-type doped Mg z Zn 1-z O structure combination, the p-type doped Mg x Zn 1-x O/p-type doped ZnO/n-type doped Mg z Zn 1-z O structure combination, the p-type doped Mg x Zn 1-x O/n-type doped Mg z Zn 1-z O structure combination, the p-type doped Mg x Zn 1-x O/intrinsic Mg y Zn 1-y O structure combination, the p-type doped Mg x Zn 1-x O/intrinsic ZnO structure combination, the p-type doped Mg x Zn 1-x O/intrinsic ZnO/n-type doped ZnO structure combination, the p-type doped Mg x Zn 1-x O/p-type doped ZnO/n-type doped ZnO structure combination, the p-type doped Mg x Zn 1-x O/n-type doped ZnO structure combination, the p-type doped ZnO/intrinsic ZnO/n-type doped Mg z Zn 1-z O structure combination, the p-type doped ZnO/n-type doped ZnO/n-type doped Mg z Zn 1-z O structure combination, the p-type doped ZnO/n-type doped Mg z Zn 1-z O structure combination, the n-type doped ZnO/p-type doped the substrate structure combination, the n-type doped Mg z Zn 1-z O/p-type doped the substrate structure combination, the p-type doped Be x Zn 1-x O/intrinsic Be y Zn 1-y O/n-type doped Be z Zn 1-z O structure combination, the p-type doped Be x Zn 1-x O/n-type doped Be y Zn 1-y O/n-type doped Be z Zn 1-z O structure combination, the p-type doped Be x Zn 1-x O/p-type doped Be y Zn 1-y O/n-type doped Be z Zn 1-z O structure combination, the p-type doped Be x Zn 1-x O/intrinsic ZnO/n-type doped Be z Zn 1-z O structure combination, the p-type doped Be x Zn 1-x O/n-type doped ZnO/n-type doped Be z Zn 1-z O structure combination, the p-type doped Be x Zn 1-x O/p-type doped ZnO/n-type doped Be z Zn 1-z O structure combination, the p-type doped Be x Zn 1-x O/n-type doped Be z Zn 1-z O structure combination, the p-type doped Be x Zn 1-x O/intrinsic Be y Zn 1-y O structure combination, the p-type doped Be x Zn 1-x O/intrinsic ZnO structure combination, the p-type doped Be x Zn 1-x O/intrinsic ZnO/n-type doped ZnO structure combination, the p-type doped Be x Zn 1-x O/p-type doped ZnO/n-type doped ZnO structure combination, the p-type doped Be x Zn 1-x O/n-type doped ZnO structure combination, the p-type doped ZnO/intrinsic ZnO/n-type doped Be z Zn 1-z O structure combination, the p-type doped ZnO/n-type doped ZnO/n-type doped Be z Zn 1-z O structure combination, the p-type doped ZnO/n-type doped Be z Zn 1-z O structure combination, and the n-type doped Be z Zn 1-z O/p-type doped the substrate structure combination can be further annealed at a temperature ranging from 400° C. to 1200° C. after deposition, and the atmosphere can be nitrogen, oxygen, argon, or mixture of nitrogen, oxygen and argon.
[0046] The atomic layer deposition based process can offer following advantages:
[0047] 1. Low deposition temperatures.
[0048] 2. Precise thickness control, to the degree of one monolayer.
[0049] 3. Accurate control of material composition.
[0050] 4. Facile doping to achieve high doping concentrations.
[0051] 5. High-quality epitaxial layer with low defect density
[0052] 6. Abrupt interface and excellent interface quality for growth of high quality heterojunctions, multiple quantum wells and so on.
[0053] 7. Large-area and large-batch capacity.
[0054] 8. High uniformity.
[0055] 9. Excellent conformality and good step coverage.
[0056] 10. Good reproducibility.
[0057] Please refer to FIG. 2 . FIG. 2 shows the X-ray diffraction pattern of the ZnO layer grown on a sapphire substrate by an atomic layer deposition process. As shown in FIG. 2 , the ZnO layer formed by the atomic layer deposition process has excellent crystal quality.
[0058] Please refer to FIG. 3 through FIG.5 . FIG. 3 shows the spontaneous emission photoluminescence spectrum at room temperature of the ZnO layer grown on a sapphire substrate by an atomic layer deposition process. FIG. 4 shows the stimulated emission photoluminescence spectra of the ZnO layer grown on a sapphire substrate by an atomic layer deposition process. FIG. 5 shows the relationship between the photoluminescence light emission intensity and the excitation intensity of the ZnO layer grown on a sapphire substrate by an atomic layer deposition process. FIG.5 shows that the light emission intensity increases super-linearly with the excitation intensity, indicating that the stimulated emission occurs at a low threshold intensity of 33.3 kW/cm 2 . The occurrence of stimulated emission indicates that the ZnO layer grown by the atomic layer deposition process has very high crystal quality and very low defect density. This shows, since the atomic layer deposition process offers the advantages such as easy and accurate thickness control, accurate control of material composition, facile doping, abrupt interfaces, high uniformity over a large area, good reproducibility, dense and pinhole-free structures, low deposition temperatures, etc., the semiconductor light-emitting device fabricated by the atomic layer deposition process has very high crystal quality and very low defect density. Besides, the semiconductor light-emitting device can probably induce lasing phenomenon, so the semiconductor light-emitting device can be more extensively utilized.
[0059] Please refer to FIG. 6 . FIG. 6 shows a semiconductor light-emitting device 3 according to an embodiment of the invention. In the embodiment, the semiconductor light-emitting device 3 is a light-emitting diode fabricated by an atomic layer deposition based process. In actual applications, the atomic layer deposition based process can be an atomic layer deposition process, a plasma-enhanced atomic layer deposition process, a plasma-assisted atomic layer deposition process, or combination of above processes. As shown in FIG. 6 , the semiconductor light-emitting device 3 includes a substrate 30 , a GaN layer 32 , a ZnO layer 34 , and electrodes 36 . In the embodiment, the substrate 30 is a sapphire substrate. In practice, the GaN layer 32 can be a GaN structure grown on the substrate 30 by a metal organic chemical vapor deposition (MOCVD) process. The ZnO layer 34 can be an intrinsic n-type ZnO layer grown on the GaN layer 32 by the atomic layer deposition process. After annealed at the temperature of 950° C. in the nitrogen atmosphere for five minutes, and then deposited with the electrodes 36 by an evaporator, an n-type ZnO/p-type GaN heterojunction light-emitting diode is finished as the semiconductor light-emitting device 3 , as shown in FIG. 6 .
[0060] Please refer to FIG. 7 . FIG. 7 shows the current density vs. voltage characteristics of the semiconductor light-emitting device 3 shown in FIG. 6 . From FIG. 7 , we can see that the semiconductor light-emitting device 3 shows a rectifying characteristic. Please refer to FIG. 8 . FIG. 8 shows the X-ray diffraction patterns of the ZnO layer 34 and the GaN layer 32 of the semiconductor light-emitting device 3 shown in FIG. 6 . As shown in FIG. 8 , the full-width at half-maximum (FWHM) of the ZnO (0002) Kα1 peak and GaN (0002) Kα1 peak are 0.05° and 0.04°, respectively, suggesting that the crystal quality of the ZnO layer 34 is good and comparable to that of GaN. Please refer to FIG. 9 and FIG. 10 . FIG. 9 shows the photoluminescence spectra of the ZnO layer 34 and the GaN layer 32 of the semiconductor light-emitting device 3 shown in FIG. 6 . FIG. 10 shows the electroluminescence spectra of the semiconductor light-emitting device 3 shown in FIG. 6 at various injection currents. Comparing FIG. 9 with FIG. 10 , it can be found that as the injection current is low, electroluminescence originates mainly from the GaN layer 32 ; as the injection current increases, the light emission from the ZnO layer 34 dominates over that from the GaN layer 32 . Accordingly, it is demonstrated that the ZnO-based semiconductor light-emitting device has good light-emitting performance due to the excellent light-emitting characteristics of ZnO.
[0061] Comparing with prior art, the method according to the invention fabricates a semiconductor light-emitting device by an atomic layer deposition process. Thereby, the method can successfully fabricate high-quality ZnO-based semiconductor light-emitting devices. In addition, since the layer formed by the atomic layer deposition process has several advantages such as easy and accurate thickness control, accurate control of material composition, facile doping, abrupt interfaces, high uniformity over a large area, good reproducibility, dense and pinhole-free structures, low deposition temperatures, etc., the semiconductor light-emitting device has very high crystal quality and very low defect density. Moreover, by the atomic layer deposition process, the semiconductor light-emitting device can be fabricated on large area so as to be more productive, and makes the associated product move competent. Furthermore, since the deposition temperature is relatively low, the damage and/or malfunction probability of equipment owing to high temperature can be reduced, and the reliability of the process and the equipment availability are further enhanced.
[0062] With the example and explanations above, the features and spirits of the invention will be hopefully well described. Those skilled in the art will readily observe that numerous modifications and alterations of the device may be made while retaining the teaching of the invention. Accordingly, the above disclosure should be construed as limited only by the metes and bounds of the appended claims. | The invention discloses a zinc-oxide-based semiconductor light-emitting device and the fabrication thereof The method according to the invention, first, is to prepare a substrate. Next, by an atomic-layer-deposition-based process, a ZnO-based multi-layer structure is formed on or over the substrate where the ZnO-based multi-layer structure includes a light-emitting region. | 7 |
BACKGROUND OF THE INVENTION
This invention relates to an improved excavation apparatus, and in particular to an improved underwater excavation apparatus.
Underwater excavation apparatus are known, eg, from GB 2 240 568 (CONSORTIUM RESOURCE et al). In that disclosure there is described. an underwater excavation apparatus comprising a hollow body with an inlet to receive water and an outlet for discharge of water. A propeller is rotatably mounted in the hollow body to draw water through the inlet and deliver a flow 6f water through the outlet. Water jets on the propeller tips rotate the propeller when water is supplied to the jets.
Such rotation causes water to be drawn into the body through the inlet and expelled from the body as a flow through the outlet. The flow can be used to displace material on the seabed.
Known prior art underwater excavation apparatus suffer from a number of problems/disadvantages, for example:
(a) Low energy efficiency due to e.g. hydrodynamic limitations of fluid jets, thus requiring extremely large and power hungry pumps to drive the system);
(b) tendency of apparatus to rotate in reaction to rotation of the propeller;
(c) difficulty in steering and positioning of the apparatus.
SUMMARY OF THE INVENTION
It is an object of at least some of the aspects of the present invention to seek to obviate or mitigate one or more of the aforementioned problems in the prior art.
According to a first aspect of the present invention there is provided an underwater excavation apparatus comprising a hollow body having at least one inlet and at least one outlet, at least one pair of impellers rotatably mounted in the hollow body and means for driving the impellers.
Advantageously, the driving means cause the impellers to be driven in contrary rotating directions, in use.
The at least one inlet may be inclined at an angle to an axis along which the at least one outlet is provided.
Preferably, there is provided at least one pair of inlets.
Preferably, the at least one pair of inlets are substantially symmetrically disposed around an axis extending from the outlet.
In one embodiment the underwater excavation apparatus comprises a pair of horizontally opposed inlets communicating with a single outlet, the outlet being disposed vertically downwards substantially midway between the two inlets, in use. In this case, the excavation apparatus is, therefore, substantially “T” shaped in profile.
In an alternative embodiment the underwater excavation apparatus comprises a pair of inlets communicating with a single outlet, the inlets being substantially symmetrically disposed around an axis extending from the outlet, the outlet being disposed vertically downwards substantially midway between the two inlets, in use. In this case, the excavation apparatus is, therefore, substantially “Y” shaped in profile.
Advantageously, the outlets are each spaced/inclined substantially 45° from the axis extending from the outlet.
At least one impeller may be provided within/adjacent each inlet.
The means for driving the/each impeller(s) may include at least one drilling motor.
The at least one drilling motor may comprise a stator and a rotor rotatably mounted in the stator, the stator being provided with a rod recess and an exhaust port, the rotor being provided with a rotor channel and at least one channel for conducting motive fluid from the rotor channel to a chamber between the rotor and the stator, the rod recess being provided with a rod which, in use, forms a seal between the stator and the rotor.
Although not essential it is highly desirable that the rotor be provided with a seal for engagement with the stator.
Preferably, the seal is made from a material selected from the group consisting of plastics materials, polyethylethylketone, metal, copper alloys and stainless steel.
Advantageously, the rod is made from a material selected from the group consisting of plastics materials, polyethylethylketone, metal, copper alloys and stainless steel.
Preferably, the stator is provided with two rod recesses which are disposed opposite one another, and two exhaust ports which are disposed opposite one another, each of the rod recesses being provided with a respective rod, the rotor having two seals which are disposed opposite one another.
The drilling motor may advantageously comprise two drilling motors arranged with their respective rotors connected together each motor comprising a stator and a rotor rotatably mounted in the stator, the stator being provided with a rod recess and an exhaust port, the rotor being provided with a rotor channel and at least one channel for conducting motive fluid from the rotor channel to a chamber between the rotor and the stator, the rod recess being provided with a rod which, in use, forms a seal between the stator and the rotor.
Preferably, the drilling motors are connected in parallel, although they could be connected in series if desired.
Advantageously, the drilling motors are arranged so that, in use, one drilling motor operates out of phase with the other. Thus, in a preferred embodiment each drilling motor has two chambers and the chambers in the first drilling motor are 90° out of phase with the chambers in the second drilling motor. Similarly, in an embodiment in which each drilling motor has four chambers, the chambers in the first drilling motor would preferably be 45° out of phase with the chambers on the second drilling motor. This arrangement helps ensure a smooth power output and inhibits stalling.
Alternatively, the at least one drilling motor may be a “Moineau”, hydraulic or a suitably adapted electric motor.
The impellers may be driven by means of a gearbox or by exploitation of the opposing reactive torque on a drive body of the motor.
When the reactive torque upon the motor body is utilised, at least one impeller may be connected to an output shaft of said motor, while at least one other impeller may be connected to the motor body.
Alternatively the impellers may be driven by a pair of motors operating in opposite directions. In such case said motors and impellers are balanced and equal.
The underwater excavation apparatus may further comprise an agitator device having mechanical disturbance means and fluid flow disturbance means.
The underwater excavation apparatus may, in use, be suspended from a surface vessel or mounted upon a sled of the type currently known for use in subsea excavation operations.
According to a second aspect of the present invention there is provided an underwater apparatus comprising a hollow body having a pair of inlets communicating with an outlet, at least one pair of impellers rotatably mounted in the hollow body and means for driving the impellers, the inlets being substantially symmetrically disposed around an axis extending from the outlet, wherein the inlets are not horizontally opposed to one another.
BRIEF DESCRIPTION OF THE DRAWINGS
Embodiments of the present invention will now be described, by way of example only, with reference to the accompanying drawings, in which:
FIG. 1 shows a cross-sectional side view of a first embodiment of an excavation apparatus according to the present invention;
FIG. 2 shows a longitudinal cross-sectional view of one embodiment of a drilling apparatus for use in the excavation apparatus in FIG. 1 according to the present invention;
FIGS. 3A-3D are cross-sectional views along line A—A of FIG. 2 showing a rotor of the motor in four different positions; and
FIGS. 4A-4D are cross-sectional views along line B—B of FIG. 2 showing the rotor in four different positions.
FIG. 5 shows a cross-sectional side view of a second embodiment of an excavation apparatus according to the present invention;
FIG. 6 shows a cross-sectional side view of a third embodiment of an excavation apparatus according to the present invention.
DETAILED DESCRIPTION OF INVENTION
Referring to FIG. 1, there is shown a first embodiment of an underwater excavation apparatus 300 a according to the present invention. The apparatus 300 a comprises a hollow body 370 a formed from a pair of horizontally opposed inlet ducts 371 a and an outlet duct 373 a , a drive motor 310 a and a pair of impellers 335 a , 340 a.
The apparatus 300 a is further provided with deflection baffles 302 a within the hollow body 370 a , suspension brackets 306 a to enable the apparatus 300 a to be suspended from a surface vessel, guide vanes 386 a to regulate the flow of fluid past the impellers 335 a , 340 a , and safety grids 385 a to seek to prevent the ingress of solid matter which may damage the impellers 335 a , 340 a.
In this first embodiment, the drive motor 310 a is provided along an axis common to the horizontally opposed inlet ducts 371 a and impellers 335 a , 340 a . An output shaft 330 a of the motor 310 a is connected to a first impeller 335 a while the second impeller 340 a is attached to a shaft 342 a connected via a swivel 325 a to an outer housing of the drive motor 310 a.
In use, motive fluid is supplied to the motor 310 a via fluid inlet 308 a which in turn causes the output shaft 330 a and impeller 335 a to rotate. Reactive torque from this rotation causes the outer housing of the drive motor 310 a to rotate in a direction opposite to that of the output shaft 330 a . This in turn results in the rotation of the second impeller 340 a . The impellers 335 a , 340 a are configured such that, despite rotating in opposite directions, they each provide an equal flow rate of water into the hollow body 370 a . Water drawn into the hollow body 370 a thus is directed via the deflection baffles 302 a through the outlet duct 373 a and towards the seabed 400 a.
The shaft 342 a and swivel 325 a may, in an alternative embodiment, be replaced by a second motor which directly drives the impeller 340 a , as hereinbefore described with reference to FIG. 5 .
The excavation device 300 a may be suspended, for example, from the bow or stern of a surface vessel, or through a moonpool of a dedicated subsea operations vessel.
In an alternative embodiment the device 300 a may be provided upon a sled (not shown) of the type currently used for subsea operations. The excavation apparatus 300 a may further be provided with an agitator device (not shown) having mechanical disturbance means and fluid flow disturbance means.
In an advantageous embodiment the motor 310 comprises a drilling motor, such as that disclosed in WO95/19488, the content of which is incorporated herein by reference.
The drilling motor 310 may comprise a first motor 20 and a second motor 50 .
The first motor 20 comprises a stator 21 and a rotor 23 . A top portion 22 of the rotor 23 extends through an upper bearing assembly 24 which comprises a thrust bearing 26 and seals 25 .
Motive fluid, e.g. water, drilling mud or gas under pressure, flows down through a central sub channel 12 into a central rotor channel 27 , and then out through rotor flow channels 28 into action chambers 31 and 32 .
Following a motor power stroke, the motive fluid flows through exhaust ports 33 in stator 21 , and then downwardly through an annular channel circumjacent the stator 21 and flow channels 35 in a lower bearing assembly 34 . A portion 36 of the rotor 23 extends through the lower bearing assembly 34 which comprises a thrust bearing 37 and seals 38 .
The ends of the stator 21 are castellated and the castellations engage in recesses in the respective upper bearing assembly 24 and lower bearing assembly 34 respectively to inhibit rotation of the stator 21 . The upper bearing assembly 24 and lower bearing assembly 34 are a tight fit in an outer tubular member 14 and are held against rotation by compression between threaded sleeves 16 and 84 .
A splined union 39 joins a splined end of the rotor 23 to a splined end of a rotor 53 of the second motor 50 . The second motor 50 has a stator 51 .
A top portion 52 of the rotor 53 extends through an upper bearing assembly 54 . Seals 55 are disposed between the upper bearing assembly 54 and the exterior of the top portion 52 of the rotor 53 . The rotor 53 moves on thrust bearings 56 with respect to the upper bearing assembly 54 .
Motive fluid flows into a central rotor channel 57 from the central rotor channel 27 and then out through rotor flow channels 58 into action chambers 61 and 62 . Following a motor power stroke, the motive fluid flows through exhaust ports 63 in stator 51 , and then downwardly through an annular channel circumjacent the stator 51 and flow channels 65 in a lower bearing assembly 64 . A portion 66 of the rotor 53 extends through a lower bearing assembly 64 . The rotor 53 moves on thrust bearings 67 with respect to the lower bearing assembly 64 and seals 68 seal the rotor-bearing assembly interface. Also motive fluid which flowed through the flow channels 35 in the lower bearing assembly 34 , flows downwardly through channels 79 in the upper bearing assembly 54 , past stator 51 and through flow channels 65 in the lower bearing assembly 64 .
The upper bearing assembly 54 and lower bearing assembly 64 are a tight fit in an outer tubular member 18 and are held against rotation by compression between threaded sleeve 84 and a lower threaded sleeve (not shown).
FIGS. 2A-2D and 3 A- 3 D depict a typical cycle for the first and second motors 20 and 50 respectively, and show the status of the two motors with respect to each other at various times in the cycle. For example, FIG. 2C shows an exhaust period for the first motor 20 while FIG. 3C, at that same moment, shows a power period for the second motor 50 .
As shown in FIG. 2A, motive fluid flowing through the rotor flow channels 28 enters the action chambers 31 and 32 . Due to the geometry of the chambers (as discussed below) and the resultant forces, the motive fluid moves the rotor in a clockwise direction as seen in FIG. 2 B. The action chamber 31 is sealed at one end by a rolling vane rod 71 which abuts an exterior surface 72 of the rotor 23 and a portion 74 of a rod recess 75 .
At the other end of the action chamber 31 , a seal 76 on a lobe 77 of the rotor 23 sealingly abuts an interior surface of the stator 21 .
As shown in FIG. 2B, the rotor 23 has moved to a point near the end of a power period.
As shown in FIG. 2C, motive fluid starts exhausting at this point in the motor cycle through the exhaust ports 33 .
As shown in FIG. 2D, the rolling vane rods 71 and seals 76 have sealed off the action chambers and motive fluids flowing thereinto will rotate the rotor 23 until the seals 76 again move past the exhaust ports 33 .
The second motor 50 operates as does the first motor 20 ; but, as preferred, and as shown in FIGS. 3A-3D, the two motors are out of phase by 90° so that as one motor is exhausting motive fluid the other is providing power.
The seals 76 are, in one embodiment, made of polyethylethylketone (PEEK). The rolling vane rods 71 are also made from PEEK. The rotors ( 23 , 25 ) and stators ( 21 , 51 ) are preferably made from corrosion resistant materials such as stainless steel.
When a seal 76 in the first motor 20 rotates past an exhaust port 33 , the motive fluid that caused the turning exits and flows downward, then through the channels 79 , past the exhaust ports 63 and the flow channels 65 .
It should be appreciated that although in the disclosed embodiment the drilling motor 310 comprises two motors 20 , 50 , with suitable adaptation, the drilling motor 310 may comprise only one motor 20 or 50 .
Referring now to FIG. 5, there is shown a second embodiment of an underwater excavation apparatus 300 b according to the present invention. Like parts of the apparatus 300 a are identified by numerals used to identify parts of the apparatus 300 a of FIG. 1, except subscripted with “b” rather than “a”.
The apparatus 300 b differs from the apparatus 300 a in that the shaft 342 a and swivel 325 a are replaced by a second motor 310 ′ b and a T-coupling 326 b . Thus in this embodiment the impellers 335 b , 340 b are driven by respective motors 310 b , 310 ′ b . In use, motive fluid is supplied to motors 310 b , 310 ′ b via fluid inlet 308 b and T-coupling 326 b.
Referring now to FIG. 6, there is shown a second embodiment of an underwater excavation apparatus 300 c according to the present invention. Like parts of the apparatus 300 b are identified by numerals used to identify parts of the apparatus 300 b of FIG. 5, except subscripted with “c” rather than “b”.
The apparatus 300 c differs from the apparatus 300 b in that whereas in apparatus 300 b the inlets 371 b are horizontally opposed, in apparatus 300 c the inlets are substantially symmetrically disposed around an axis extending from outlet 373 c , such that the apparatus 300 c is substantially “Y” shaped. In this embodiment there is, therefore, provided a Y-coupling 326 c.
The embodiments of the invention hereinbefore described are given by way of example only, and are not meant to limit the scope of the invention in any way. It should be particularly appreciated that the drilling motor 310 is suitable for use in any of the disclosed embodiments. | An improved underwater excavation apparatus achieves efficiency and control of movement through provision of a hollow body having at least one inlet and at least one outlet, at least one pair of impellers coaxially displaced one from the other and rotatably mounted in the hollow body, and a mechanism for driving the impellers in contrary rotating directions. The underwater excavation apparatus comprises a pair of horizontally opposed inlets communicating with a single outlet, the outlet being disposed vertically downwards substantially midway between the two inlets, in use. The excavation apparatus may, therefore, be substantially “T” or “Y” shaped. The mechanism for driving the impellers may include at least one drilling motor. | 4 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a method and an apparatus for forming a patterned photoresist layer. More particularly, the present invention relates to a method and an apparatus for forming a patterned photoresist layer wherein an overlay offset is measured and fed back in real time.
2. Description of the Related Art
In accompany with the advances in semiconductor industry, numerous high-performance semiconductor apparatuses or integrated circuits including millions of devices like transistors, capacitors and resistors have been developed. To enhance the performance of a semiconductor apparatus or an integrated circuit, its integration degree has to be increased. More specifically, the number of conductive layers has to be increased and/or the critical dimension (CD) of devices has to be reduced.
Since the integration degrees of integrated circuits increase continuously, the alignment precision between different wafer layers becomes an important issue. For example, when misalignment occurs between conductive lines and plugs of an integrated circuit, the integrated circuit may have a low performance or even fail. Misalignment also occurs easily in doping or ion-implantation process lowering the performance of the integrated circuit.
Generally, the pattern of a film or doping/ion-implantation regions in a film in an integrated circuit is defined by a patterned photoresist layer formed in a lithography process including an exposure step and a development step. Therefore, it is necessary to measure the overlay offset of the patterned photoresist layer after the lithography process for detecting possible misalignment.
FIG. 1 illustrates a process flow for forming a patterned photoresist layer in the prior art. Referring to FIG. 1 , a photoresist layer is coated on a wafer (S 100 ), exposed using an exposure tool (S 110 ) and then developed (S 120 ) to form a patterned photoresist layer. The overlay offset between the photoresist patterns and another film is then measured (S 130 ). The next step (S 140 ) is to determine whether the overlay offset is within a tolerable range or not, i.e., whether the photoresist patterns are sufficiently aligned with other films or not. If the answer is yes, the next process is performed (S 150 ). Otherwise, the photoresist layer is removed for rework, and a control signal is fed back to the exposure tool from the overlay measurement tool (S 160 ) so that the exposure conditions in the rework can be adjusted accordingly.
In the prior art, the overlay measurement tool is usually an ACML (product name) tool. However, since the ACLM tool is used after the development step, the development liquid is wasted when a rework is required. Moreover, an ACLM tool cannot measure an overlay offset and feedback a control signal to the exposure tool in real time, so that the wafers processed before reception of the control signal have to be reworked when the overlay offset measured is not within the tolerable range. In addition, an ACML tool is usually quite expensive increasing the manufacturing cost. Furthermore, the use of an ACLM tool requires overlay marks being formed on the scribe line regions of a wafer, so that the scribe line regions cannot be further narrowed.
SUMMARY OF THE INVENTION
Accordingly, this invention provides a method for forming a patterned photoresist layer, in which an overlay offset of the photoresist patterns is fed back in real time for reducing the cycle time and the rework time in the lithography process.
This invention also provides an apparatus for forming a patterned photoresist layer that has a mechanism capable of feeding back an overlay offset of the photoresist patterns in real time for reducing the cycle time and the rework time in the lithography process.
A method for forming a patterned photoresist layer of this invention is suitably used to form a patterned photoresist layer aligned with a predetermined wafer layer, including the following steps (a)–(e). A photoresist layer is formed on a substrate in step (a) and then exposed in step (b). The overlay offset between the exposed portions of the photoresist layer and the predetermined layer is measured in step (c), and the overlay offset is used to determine whether the alignment precision of the exposed portions of the photoresist layer is acceptable or not in step (d). If the answer is yes, the photoresist layer is developed in step (e).
If the alignment precision is not acceptable, however, a step (f) of removing photoresist and the above steps (a)–(d) are repeated in sequence for at least one cycle until the alignment precision is determined to be acceptable in step (d). In each cycle of steps, the exposure condition is calibrated according to the overlay offset measured in step (c) of the preceding cycle.
According to an embodiment of this invention, a latent image is formed in the photoresist layer in the exposure step, and the overlay offset measurement is done by scanning the latent image with a laser beam and analyzing the signals generated from the laser scanning. The overlay offset is used to determine whether the alignment precision of the latent image is acceptable or not.
Another method for forming a patterned photoresist layer of this invention includes the following steps (a)–(e). A photoresist layer is formed on a substrate in step (a). In step (b), an exposure/overlay-measurement tool is used to expose the photoresist layer to form a latent image therein. In step (c), the overlay offset between the latent image and a predetermined wafer layer is measured using the exposure/ overlay-measurement tool. The overlay offset is compared with a predetermined value in step (d). If the overlay offset is smaller than the predetermined value, the photoresist layer is developed in step (e).
If the overlay offset is larger than the predetermined value, however, a step (f) of removing photoresist and the above steps (a)–(d) are repeated in sequence for at least one cycle until the overlay offset is found to be smaller than the predetermined value in step (d). In each cycle of steps, the exposure condition is calibrated according to the overlay offset measured in step (c) of the preceding cycle. The method for calibrating the exposure condition includes, for example, feeding back a control signal generated based on the overlay offset to the exposure/overlay-measurement tool before the photoresist layer is removed to order the latter to calibrate the exposure condition.
According to an embodiment of this invention, the aforementioned overlay offset measurement is done by scanning the latent image of the photoresist layer with a laser beam and analyzing the signals generated from the laser scanning. The overlay offset is used to determine whether the alignment precision of the latent image is acceptable or not.
An apparatus for forming a patterned photoresist layer of this invention is suitably used to form a patterned photoresist layer aligned with a predetermined wafer layer, including at least a photoresist coating tool, an exposure/overlay-measurement tool, a development tool and a substrate carrying tool. The photoresist coating tool is for coating a photoresist layer on a substrate. The exposure/overlay-measurement tool is used to expose the photoresist layer to form a latent image therein and to measure the overlay offset between the latent image and the predetermined layer. The development tool is for developing the photoresist layer, and the substrate carrying tool is connected between the photoresist coating tool, the exposure/overlay-measurement tool and the development tool for carrying the substrate between them.
According to an embodiment of this invention, the above apparatus may further include a photoresist removal tool. The photoresist removal tool may be connected with the exposure/overlay-measurement tool and/or the photoresist coating tool via the substrate carrying tool.
The substrate carrying tool can carry the substrate to the photoresist removal tool or the development tool according to the overlay offset value. Specifically, when the overlay offset is overly large, the substrate carrying tool will carry the substrate to the photoresist removal tool for rework. When the overlay offset is within a tolerable range, the substrate carrying tool will carry the substrate to the development tool for developing the photoresist layer.
The above exposure/overlay-measurement tool is constituted of an exposure module and an overlay measurement module, for example. The exposure module is for forming a latent image in the photoresist layer. The overlay measurement module is for measuring the overlay offset between the latent image and the predetermined layer and for feeding back a control signal generated based on the overlay offset to the exposure module.
The exposure module includes an exposure light source and a photomask, for example, wherein the exposure light source may be disposed over the substrate, and the photomask may be disposed between the exposure light source and the substrate. The overlay measurement module may include a laser light source, a signal reception device and a signal feedback device. The laser light source is for scanning the latent image, the signal reception device is for receiving a test signal generated from the laser scanning that contains the information of the overlay offset. The signal feedback device is used to generate a control signal based on the test signal and feedback the control signal to the exposure module.
Since the overlay measurement is performed after the exposure step and before the development step in this invention, the overlay offset can be fed back in real time to avoid undesired rework.
It is to be understood that both the foregoing general description and the following detailed description are exemplary, and are intended to provide further explanation of the invention as claimed.
BRIEF DESCRIPTION OF THE DRAWINGS
The accompanying drawings are included to provide a further understanding of the invention, and are incorporated in and constitute a part of this specification. The drawings illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention.
FIG. 1 illustrates a process flow for forming a patterned photoresist layer in the prior art.
FIG. 2 illustrates a process flow for forming a patterned photoresist layer according to a preferred embodiment of this invention.
FIG. 3 illustrates an apparatus for forming a patterned photoresist layer according to the preferred embodiment of this invention.
FIG. 4 schematically depicts the exposure/overlay-measurement tool of FIG. 3 .
DESCRIPTION OF THE PREFERRED EMBODIMENTS
To solve the aforementioned problems in the prior art, this invention integrates an overlay measurement module and an exposure module together so that the overlay measurement can be performed after the exposure step and before the development step to monitor the overlay offset in real time. By doing so, both the cycle time and the rework time in the lithography process can be reduced effectively.
FIG. 2 illustrates a process flow for forming a patterned photoresist layer according to the preferred embodiment of this invention. At first, a substrate is provided with some films formed thereon. The substrate is, for example, a wafer for fabricating semiconductor apparatuses or integrated circuits, a glass substrate, a quartz substrate, a plastic substrate or a silicon substrate for fabricating display panels, or a plastic substrate or a ceramic substrate for fabricating printed circuit boards (PCB).
Thereafter, a photoresist layer is formed on the substrate (S 200 ). The photoresist layer is then exposed, and the overlay offset between the exposed portions of the photoresist layer and a predetermined wafer layer is measured (S 210 ). In this embodiment, the exposure step and the overlay measurement step are done in the same exposure/overlay-measurement tool, which is used to expose the photoresist layer to form a latent image therein and then measure the overlay offset between the latent image and the predetermined wafer layer.
It is noted that the patterned photoresist layer formed in this embodiment may be one used to define patterns in a semiconductor device or an integrated circuit, such as, patterns of conductive lines, patterns of openings in a dielectric layer, patterns of conductive plugs or patterns of doped regions. Moreover, the patterned photoresist layer may serve as a mask in a film etching process, a doping process, an ion implantation process or a film deposition process. Nevertheless, this invention is not restricted to apply to the above cases, and one skilled in the art may properly modify the aforementioned method for other cases requiring precise alignment without departing from the scope or spirit of the invention.
The overlay offset value is then used to determine whether the alignment precision of the photoresist patterns is acceptable or not (S 220 ). More specifically, the measured overlay offset may be compared with a predetermined value to determine whether the alignment precision of the photoresist layer is acceptable or not. If the overlay offset is smaller than the predetermined value, i.e., the overlay offset is within a tolerable range, the photoresist layer is developed to form photoresist patterns (S 230 ). Thereafter, the patterned photoresist layer is used as a mask to perform a film etching process, a doping process, an ion implantation process or a film deposition process to form a patterned film or doped regions with good alignment precision (S 240 ).
If the overlay offset is larger than the predetermined value, however, a control signal generated based on the overlay offset is fed back to the exposure/overlay-measurement tool, and the photoresist layer is removed for rework (S 250 ). The feedback of the control signal is prior to removal of the photoresist layer, for example. Thereafter, the steps S 200 –S 220 are repeated again, wherein the exposure condition of the photoresist layer is calibrated according to the control signal. If the overlay offset is found to be smaller than the predetermined value in step S 220 , the photoresist layer is developed to form photoresist patterns (S 230 ). If the overlay offset is still larger than the predetermined value, the steps S 250 , S 200 , S 210 and S 220 are repeated in sequence for at least one cycle until the overlay offset is found to be smaller than the predetermined value, and then the photoresist layer is developed to form photoresist patterns (S 230 ).
FIG. 3 illustrates an apparatus for forming a patterned photoresist layer according to the preferred embodiment of this invention. The apparatus 300 may be constituted of a photoresist coating tool 400 , an exposure/overlay-measurement tool 500 , a development tool 600 and a substrate carrying tool 700 . The photoresist coating tool 400 is for coating a photoresist layer on the substrate. The exposure/overlay-measurement tool 500 is used to expose the photoresist layer to form a latent image therein and to measure the overlay offset between the latent image and the predetermined layer. The development tool 600 is for developing the photoresist layer, and the substrate carrying tool 700 is connected between the photoresist coating tool 400 , the exposure/overlay-measurement tool 500 and the development tool 600 for carrying the substrate between them.
The apparatus 300 for forming a patterned photoresist layer may further include a photoresist removal tool 800 . The photoresist removal tool 800 may be connected with the exposure/overlay-measurement tool 500 and/or the photoresist coating tool 400 via the substrate carrying tool 700 .
The substrate carrying tool 700 can carry the substrate to the photoresist removal tool 800 or the development tool 600 according to the overlay offset value. Specifically, when the overlay offset is overly large, the substrate carrying tool 700 will carry the substrate to the photoresist removal tool 800 for rework. When the overlay offset is within a tolerable range, the substrate carrying tool 700 will carry the substrate to the development tool 600 for developing the photoresist layer.
FIG. 4 schematically depicts the exposure/overlay-measurement tool of FIG. 3 . The exposure/overlay-measurement tool 500 is constituted of an overlay measurement module 510 and an exposure module 520 , for example. The exposure module 520 is for forming a latent image in the photoresist layer. The overlay measurement module 510 is for measuring the overlay offset between the latent image and the predetermined layer and for feeding back a control signal generated based on the overlay offset to the exposure module 520 for calibrating the exposure condition.
Referring to FIG. 4 again, the overlay measurement module 510 may include a laser light source 512 , a signal reception device 514 and a signal feedback device 516 . The laser light source 512 is used to scan the latent image, the signal reception device 514 is for receiving a test signal S MEASUREMENT generated from the laser scanning that contains the information of the overlay offset. The signal feedback device 516 is used to generate a control signal S CONTROL based on the test signal S MEASUREMENT and feedback the control signal S CONTROL to the exposure module 520 for calibrating the exposure condition. The exposure module 520 includes an exposure light source 522 and a photomask 524 , for example, wherein the exposure light source 522 may be disposed over the substrate and the photomask 524 may be disposed between the exposure light source 522 and the substrate.
As mentioned above, since the exposure step and the overlay measurement step are done in the same tool in this invention, the cycle time in the lithography process can be reduced. Moreover, the overlay measurement is performed after the exposure step and before the development step, so that the overlay offset can be fed back to the exposure module in real time to avoid undesired rework. Meanwhile, since the overlay measurement is performed before the development step, the accuracy thereof is better without being affected by the process parameters of the development step. Furthermore, this invention adopts an exposure/overlay-measurement tool instead of the conventional expensive ACML tool, so that the manufacturing cost can be reduced.
In addition, the scanning precision of the exposure/overlay-measurement tool is the same as that of the stepper in current exposure tools, so that the overlay measurement is more precise satisfying the requirements of the next generation of manufacturing process. Moreover, in this invention, sufficient alignment precision of the photoresist patterns can be achieved with slight modification, or even without any modification, to the overlay marks. Therefore, the manufacturing cost is not worried about. Furthermore, this invention allows the scribe line regions on a wafer to be narrowed, so that the gross die number of the wafer can be increased.
It will be apparent to those skilled in the art that various modifications and variations can be made to the structure of the present invention without departing from the scope or spirit of the invention. In view of the foregoing, it is intended that the present invention covers modifications and variations of this invention provided they fall within the scope of the following claims and their equivalents. | A method for forming a patterned photoresist layer aligned with a predetermined layer is described. A photoresist layer is formed on a substrate and then exposed. The overlay offset between the exposed portions of the photoresist layer and the predetermined layer is measured for determining whether the exposed portions of the photoresist layer are aligned with the predetermined layer. A development step is performed when the exposed portions of the photoresist layer are found to align with the predetermined layer. An apparatus for forming a patterned photoresist layer is also described, which utilizes the aforementioned method and has a mechanism capable of feeding back the overlay offset in real time for reducing the cycle time and the rework time in the lithography process. | 6 |
BACKGROUND OF THE INVENTION
Cast or molded concrete pipe is used conventionally for drainage purposes in connection with sewage and leaching fields in particular. This type of pipe which ranges in size from small diameters to quite large diameters has been formed conventionally by casting or molding a solid or unperforated concrete pipe, a normal type of fluid conduit, and then perforating the pipe in a convenient manner.
One way in which the perforations have been formed is to extend large cores diametrically across the molds when the pipe is formed so as to produce apertures in opposite sides of the pipe after the concrete sets in the molds and around the cores. Naturally, thereafter, it is necessary to remove the cores before the pipe can be removed from the mold. Removal frequently causes damage to the pipes resulting in an inferior product. Also, the cores can interfere with the reinforcing rods in the pipes.
A second method of forming perforations in use today is to punch or cut holes in the formed pipe. This is done indiscriminately in the field in many cases and causes damage to the reinforcing rods because as the perforations are formed the rods are often broken or cut. This provides for a weakened and damaged concrete pipe. Also, the concrete will often deteriorate around the cut or punched holes and affect the longevity and efficiency of the pipe in use. Damage to the reinforcing bars during formation of the perforations can be caused by negligence, lack of knowledge on the part of the persons forming the perforations or because the location of the intersecting bars is not known when the choice of location of the perforations is made. In the latter case, it is a matter of luck whether the perforation is made between bars or at a location of a bar necessitating the cutting or damaging of the bar or bars contacted.
In any event, formation of perforated or slotted pipe for drainage or leaching field systems by the methods known today clearly results in an inferior and undesirable product. There is clearly a need for an improved slotted concrete pipe of high quality and undamaged integrity and one which can be quickly and efficiently formed by existing pipe forming methods without materially adding to the cost of the forming process.
SUMMARY OF THE INVENTION
With the above background in mind, it is among the primary objectives of the present invention to provide a method of forming slotted concrete pipe whereby the slots are formed as the pipe is formed and the molded or cast concrete pipe is the finished product. There is no need for further processing steps to form the perforations. The process is carried out by conventional concrete pipe forming methods such as pouring of concrete into a mold or preform or by applying the concrete to a mold wall by means of centrifugation.
It is an objective of the present invention to provide a slotted concrete pipe formed by mounting a plurality of inserts in the mold along with a grid of reinforcing bars and thereafter applying concrete to the mold surrounding and capturing the reinforcing bars and inserts in predetermined fixed position. The pipe is then removed from the mold as a finished product. The inserts formed through passageways through the pipe wall to provide the necessary perforations or slots.
It is an objective to provide inserts in the system which can be easily attached to the grid of reinforcing bars to fix them in predetermined locations within the mold prior to introduction of the concrete so that when the concrete sets the inserts will be at the desired location for the slots in the finished concrete pipe.
It is an objective to provide inserts with clips in the form of spring-like members which clip the inserts to the bars and hold them in fixed position. The inserts are designed to conform to the cylindrical configuration of the pipe while retaining a somewhat rectangular configuration for strength and support with a through passageway for access to the interior and exterior of the pipe formed around each insert.
The types of inserts contemplated by the invention include ones with means to facilitate their positioning within the interstices of the grid of reinforcing bars and attachment to the reinforcing bars while providing a through passageway between the interior and exterior of the finished pipe. For example, one embodiment employs a resilient strip for resiliently interweaving and locking with the grid of bars. The strip is provided with a plurality of apertures to receive plugs therethrough in frictional interengagement. Each plug is open at both ends and provides a through passageway between the interior and exterior of the pipe when attached to the strip and the strip is attached to the grid.
In certain pipe forming methods, it is desirable to have one or both of the ends of the inserts closed while the concrete is being applied and is permitted to set to avoid plugging of the holes through the inserts and, accordingly, the perforations used to form the slots in the finished pipe. For this purpose, end plugs can be formed on the open ends or edges of the inserts to close the passageway therethrough and they can be removed in a conventional manner such as by cutting or punching after the pipe is formed thereby opening the through passageway for each perforation or slot. This is particularly useful in pipe forming procedures such as the centrifugal force procedure for application of the concrete within the mold.
The system of the present invention is quick and efficient and inexpensive to manufacture and assemble. Common types of reinforcing bar grids can be used and the inserts attached in a quick and efficient manner by clips as described above or by resilient interlocking of the inserts with the bars. The concrete is applied in conventional fashion. The finished pipe is removed from the mold in a conventional fashion for use. Naturally when end plugs are used in the inserts they would be removed to open the through passageway of the slots before or after the pipe is removed from the mold and the pipe is then ready for use.
The inserts remain within the finished pipe along with the reinforcing bars for the life of the pipe. Thus there is no further manufacturing step required and no danger of damaging the integrity of the pipe after it has been formed. It is ready for use.
The inserts can be formed of a variety of different types of inexpensive materials having the desired strength and resiliency where necessary for use. For example, common types of plastics such as polypropylene or polyethylene have been found to be effective for the insert material. For attachment means resilient metal or plastic spring clips or strips can be employed for the various embodiments. The reinforcing rods would be of a conventional nature such as commonly used iron or steel bars employed with concrete pipes.
In summary, a unique insert is present for use in forming slotted concrete pipe. The pipe is of the type which is in the form of a hollow tube of concrete with a grid of reinforcing bars embedded therein. A plurality of the unique inserts are also embedded in the concrete pipe. Each insert has a through passageway to form a slot between the interior of the concrete pipe and the exterior thereof. The inserts are formed as the pipe is formed and remain embedded in the pipe during use. No further manufacturing steps are required.
Preferably, the inserts are mounted in the pipe without affecting the integrity of the grid of reinforcing bars. The inserts can be fixed in position with respect to the bars and the ultimate pipe by attaching them to the bars during the forming of the pipe. The inserts are designed so that they can be utilized in conventional types of casting or molding pipe procedures such as pouring or centrifugation of the concrete in application to a mold.
With the above objectives among others in mind, reference is made to the attached drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
In The Drawings:
FIG. 1 is a perspective view of the method of forming a concrete pipe of the invention showing an initial step of application of inserts to a grid of reinforcing bars and then insertion of the assembly into a mold;
FIG. 2 is a sectional elevation view thereof with the reinforcing bars and inserts in the mold and concrete being poured into the mold to form the pipe;
FIG. 3 is a side elevation view of the resultant formed slotted concrete pipe removed from the mold of FIG. 2;
FIG. 4 is a perspective view of an alternative method of forming the concrete pipe of the invention and showing an alternative type of insert being applied to the grid of reinforcing bars and the combination being inserted into a centrifugation mold;
FIG. 5 is a sectional elevation view of the assembly in the centrifugation mold and concrete being applied by centrifugal force;
FIG. 6 is a side elevation view of the resultant formed slotted concrete pipe removed from the mold of FIG. 5;
FIG. 7 is an enlarged end elevation view of the insert of the process of FIGS. 1-3 mounted to the grid of reinforcing bars;
FIG. 8 is a top plan view thereof;
FIG. 9 is a sectional side view thereof taken along the plane of line 9--9 of FIG. 7;
FIG. 10 is a perspective view of the insert of FIGS. 7-9;
FIG. 11 is an enlarged end elevation view of an insert of the embodiment of FIGS. 4-6 mounted to the grid of reinforcing bars;
FIG. 12 is a top plan view thereof;
FIG. 13 is a sectional side view thereof;
FIG. 14 is an exploded perspective view thereof;
FIG. 15 is a perspective view of a further alternative embodiment of the insert of the invention; and
FIG. 16 is a fragmentary perspective view of an alternative embodiment of a ladder arrangement of mounting strips for inserts of the invention.
DETAILED DESCRIPTION
There are several well known methods of forming concrete pipe of the type which is used in leaching fields and for drainage of sewage or water from large catch basins and similar structures. Two of the more conventional ways is by pouring concrete into a mold containing suitable reinforcing rods and permitting the concrete to set and form a pipe which can then be removed from the mold for use. Another conventional way is by placing reinforcing rods in a mold and then applying concrete along the wall of the mold by a centrifugal force device whereupon the concrete sets and can be removed from the mold for use as a pipe. Another conventional way is by the vibrating method. The pipe of the present invention can be formed in either of these two conventional processes without the necessity of alteration or change of the molding or casting processes. This is true with respect to all of the different types of inserts of the invention used for forming slots or perforations in concrete pipe.
An example of a concrete pipe 20 of the present invention employing one of the various types of inserts of the present invention and which is formed by a concrete pouring method is depicted in FIGS. 1-3.
In FIG. 1, a grid 22 of reinforcing bars in the configuration of the pipe is provided. Conventionally these bars are formed of steel or iron and are interconnected by welding or any similar conventional process. The grid is formed with a plurality of spaced parallel axially running bars 24 intersecting a plurality of circular circumferential parallel spaced bars 26. The bars 24 are interconnected with the bars 26 at their points of intersection. Spaces of interstices 28 are formed between the bars and are generally rectangular in configuration. The grid is open at both ends to conform to the ultimate configuration of the pipe 20.
A plurality of inserts 30 are mounted in the spaces 28 between the bars 24 and 26. The number of inserts 30 and the arrangement is a matter of choice. The purpose is to locate perforations or slots for the pipe. This arrangement of the grid and the inserts 30 is then positioned in a mold 32 having the configuration for the ultimate pipe. As shown in FIG. 2, the mold has a base 34, an outer wall 36 and an inner wall 38 to form a chamber therebetween for receipt of the grid and inserts and the concrete poured from a conventional concrete pourer 40. The concrete fills the space surrounding the grid and insert assembly and is permitted to set to form a concrete pipe 20 which is removed from the mold in the final configuration for use as depicted in FIG. 3. The inserts 30 and the grid 22 are permanently mounted in the pipe in position to form slots for drainage purposes. If desired, the inserts 30 can be initially formed with end plugs sealing the through passageway 42 of each insert to prevent plugging of this through passageway by concrete during pouring. Thereafter, the end plugs would be removed providing a through passageway 42 between the interior and exterior of the finished concrete pipe 20.
An example of the concrete pipe 20a of the invention is depicted in FIGS. 4-6. This pipe 20a has a different type of insert utilized and is formed by the conventional type of centrifugation method for applying the concrete to the mold. Similar parts to the embodiment of FIGS. 1-3 bear similar numbers with the addition of the subscript a. The same type of grid 22a is formed with the intersecting arrangement of bars 24a and 26a so as to form at their interstices spaces 28a. Inserts 30a are positioned in spaces 28a and are mounted to bars 24a and 26a of grid 22a. Each of the inserts 30a includes a mounting strip 44 of flexible material with end tabs 46 to resiliently engage with adjacent axial bars 26a. A group of apertures 48 are in the strip. Each aperture 48 is adapted to have a plug 50 extended therethrough. Each plug 50 is open at both ends, the inner and outer edges, to provide a through passageway 52 for the slot in the finished concrete pipe 20a. The plugs are frictionally mounted in the apertures 48 and the strips are applied to the grid in a predetermined arrangement to provide for the appropriate slot locations for the finished pipe 20a. The assembly of the interengaged grid 22a and inserts 30a is then inserted into a mold 54. The mold 54 has a longitudinal circumferential side wall 56 conforming to the ultimate configuration of the concrete pipe being formed. A conventional type of centrifugal applicator 58 is then utilized. It travels along the length of mold 54 and by rotation expels under centrifugal force concrete through aperture 60 whereby the concrete is directed against the inner surface of the side wall 56 where it sets to form a tubular pipe. The concrete surrounds the assembly of grid 22a and inserts 30a which become embedded in the hardened concrete pipe. The assembly is then removed from the mold 54 and is ready to use as pipe 20a with an appropriate drainage slot at the location of each insert 30a.
As discussed in connection with the embodiment of FIGS. 1-3, each plug 50 of insert 30a may contain end plugs closing off the through passageway 52 during the assembly process until the concrete pipe has been formed. Thereafter, the end plugs can be removed in a conventional manner such as by cutting or punching the plugs out opening passageways 52 to provide the slots in the pipe 20a.
FIGS. 7-10 show the details of insert 30 depicted in connection with the embodiment of FIGS. 1-3. Insert 30 is substantially rectangular in configuration with a relatively flat top wall 62 and a corresponding flat bottom wall 64. The top and bottom walls are substantially parallel and are interconnected by upright side walls 66 and 68. The ultimate rectangular or box-like configuration has a through passageway 42 therethrough to provide the slot for the pipe 20. As a matter of choice an intermediate support 70 can be included to maintain the spacing between walls 62 and 64 when the insert is subjected to forces from the surrounding concrete in the pipe. It has been found that a conventional low cost relatively inert material works effectively for insert 30 such as a plastic, for example polypropylene or polyethylene. Use of a plastic material such as polypropylene or polyethylene facilitates formation of the insert and also adds longevity to the insert as it resides in the pipe.
It should also be noted that the inner and outer edges 72 of the top wall 62 and the bottom wall 64 are arcuate in configuration to conform with the radius of curvature of the pipe. This facilitates introduction of the insert into the mold and forming of the pipe with the inserts extending from the inner surface to the outer surface of the pipe wall to form the through passageway for the slot. Insert 30 is also smaller than the rectangular space formed by adjacent pairs of circumferentially and axially extending bars.
Insert 30 includes a downward projecting tab 74 on each side and an upwardly extending tab 76 in alignment therewith at each side. These pairs of actually projecting tabs form engaging surfaces with the adjacent circumferential bars 26 of grid 22. This provides for tight frictional interengagement in the axial direction for the insert 30 as it is positioned between adjacent bars 26.
Extending from each side wall 66 and 68 is an upstanding stop 78 spaced from a laterally extending stop 80. The space 82 between stop 78 and stop 80 forms a pathway for a central portion of a mounting spring clip 84. In this way, a spring clip 84 is positioned at each side of insert 30. The spring clip is formed of a resilient material such as spring steel or plastic and has an upper free end in the shape of a hook 86 for extension around a circumferential grid bar 26. Hook 86 extends into a somewhat U-shaped section 88 to be embedded in the concrete and to provide resilience for the spring clip. U-shape section 88 extends into a straight section 90 which extends through space 82 to capture one side of insert 30. Straight section 90 terminates in a lateral arcuate tab 92 which engages with a circumferential bar 26. The length of spring clip 84 is chosen so that end 86 and end 92 can be mounted on circumferential bars 26 with one intermediate circumferential bar 26 therebetween. Thus, by use of the spacing tabs 74 and 76 and the spring clips 84 at both sides of insert 30, the insert is mounted to the grid 22. It should be noted that this mounting is accomplished without the need for interferring with the integrity or altering the shape or configuration of the grid or any of its members.
As stated above, end plugs can be positioned at the location of through passageway 42 at both the inner and outer edges of insert 30 which can be removed after the concrete has been applied in surrounding relationship with respect to the interengaged grid 22 and inserts 30. The result is a slotted pipe 20 as depicted in FIG. 3.
The alternative insert 30a shown in connection with the embodiment of FIGS. 4-6 is depicted in detail in FIGS. 11-14. Strip 44 is formed of a resilient metal or plastic material and includes a pair of end tabs 46 which are arcuate to partially surround a pair of adjacent axial bars 24a. In turn, the strip is wide enough so that it has sufficient width to engage with a pair of adjacent circumferential bars 26a. In this manner, the resilient strip can be wedged in the interstices of the adjacent pairs of axial bars 24a and circumferential bars 26a so as to provide mounting means for the insert on the grid 22a. To facilitate provision of the desired resilience for the strip 44, it is provided with suitable notches 94 adjacent opposing longitudinal edges and in alignment with central holes 96. There are four central holes 96 for each strip 44 and between each pair of central holes 96 is an aperture 48 which conforms to the shape of a plug 50 to be inserted therethrough for frictional engagement therewith. Thus, there are three apertures 48 and accordingly three plugs 50 can be used for each insert 30a. Plug 50 has a hollow rectangular shaped main body portion 98 extending into a wider trumpet portion 100. Plug 50 can be formed of one piece or two frictionally interengaged or adhesively bonded pieces. Plugs 50 are formed of plastic and so is strip 44. Portions 98 and 100 have through passageways which form a through continuous passageway 52 for plug 50 which in turn forms a slot for the completed concrete pipe 20a. As described above, each plug 50 can be provided with end plugs to protect passageway 52 while the pipe is being formed. An example of an end plug is depicted in connection with this embodiment as end plug 102. After formation of the pipe 20a, end plug 102 and similar end plugs for one or both ends of all inserts 30a can be removed thereby providing the through slots for the pipe at the desired locations. Once again the number of inserts 30a is a matter of choice and their location is also a matter of choice. They are permanently embedded in the concrete pipe to provide permanent slots for the pipe. They do not have any deleterious effect on the bars of grid 22a and are mounted to the grid bars in the interstices of the bars. As with all of the embodiments in connection with this invention, the concrete is formed around the inserts which are permanently mounted in the concrete necessitating no removal after the concrete of the pipe has set.
Two additional modifications are depicted in FIGS. 15 and 16. A modified insert 30b is shown in FIG. 15 and is somewhat similar to the insert 30 discussed above. However, in place of the stops 78 and 80 forming space 82 for the spring clip 84, a lateral projecting guideway 104 is provided at each end of insert 30b and spaced from the inner surface 106 of guideway 104 is a pair of buttons 108 and 110. The buttons 108 and 110 are small projections from each side of the insert 30b and are designed to snap-fit past an axial bar 26 to capture the bar between buttons 108 and 110 and the inner surface 106 of guideway 104. With an arrangement of this type on either end of insert 30b, there is no need for an additional component such as spring clip 84 in connection with insert 30. Otherwise, insert 30b is mounted in the same manner with respect to grid 22 with similar upwardly and downwardly extending space is to frictionally engage with adjacent circumferential ribs 24 to complete the mounting of the insert on the grid.
FIG. 16 shows a modification for insert 30a discussed above. It results in an insert arrangement 30c which is identical with respect to insert 30a with the exception that each adjacent pair of strips 44c are interconnected in a ladder arrangement by a pair of parallel resilient tie rods 112. This ladder arrangement of insert strips facilitates assembly of the inserts to the grid 22a. The arrangement of strips of insert 30c are spaced so that they mate with appropriate interstices of the bars of the grid. The strips 44c are mounted in the same manner as the strips 44 with respect to resilient coupling to the grid bars. Appropriate plugs are then inserted through the appropriate apertures in the strips to produce the resultant inserts for the ultimate concrete pipe.
Naturally in addition to polypropylene and polyethylene other conventional substitutes therefor well known in the art are acceptable for use in forming the inserts. Also, certain metals such as aluminum can be used.
It should also be noted that extending tabs 76, 76c and 74, 74c at each side of the inserts 30a and 30c ensure that the insert is sufficiently spaced from the ribs so that concrete can completely surround the reinforcing bars thereby facilitating formation of the most desirable concrete pipe structure.
The slots of the depicted embodiments are rectangular in configuration, however, it should be kept in mind that other configurations can also be easily utilized such as round slots.
The width of the inserts is a matter of choice depending upon the thickness of pipe wall being constructed.
In certain environments, the embodiments of inserts 30a and 30c are desirable and for other environments the embodiments of inserts 30b and 30d are desirable. The inserts are interchangeable independent of the concrete forming method used. For example, in certain drainage situations the wider trumpet opening on the outer end of the plugs of inserts 30b and 30d facilitates operation of the pipe in drainage use. The trumpet configuration also provides an undersurface ledge where it joins the reduced diameter portion which engages with the strip through which the plug extends providing improved stability for the assembly.
Thus the several aforenoted objects and advantages are most effectively attained. Although several somewhat preferred embodiments have been disclosed and described in detail herein, it should be understood that this invention is in no sense limited thereby and its scope is to be determined by that of the appended claims. | Concrete pipe including a hollow tube of concrete with a grid of reinforcing bars embedded therein. A plurality of inserts are embedded in the concrete pipe in between the bars of the grid and have passageways therethrough to form slots between the interior of the concrete pipe and the exterior thereof at predetermined locations to form slotted concrete pipe. The inserts are attached to the grid of reinforcing bars during formation of the pipe and the concrete is introduced to surround the grid and inserts and is permitted to set. Thereafter, the formed concrete pipe contains embedded reinforcing bars and inserts in predetermined locations resulting in a slotted reinforced concrete pipe. | 4 |
This invention relates to methods and apparatus for repairing pipelines; and more particularly relates to a novel and improved method and apparatus for sealing off sections of a pipeline, such as, a gas main for the purpose of repair, servicing or modification of the main.
BACKGROUND AND FIELD OF INVENTION
The repair of gas mains can present substantial hazards to workmen and others in the vicinity who are exposed to large volumes of gas if the main is not effectively sealed off against leakage. Various types of inflationary bags have been devised to stop-off cast iron and large diameter steel pipe and, while these have been designed to discourage any tendency to be blown downstream due to slippage or leakage, have not been completely failsafe in use. Moreover, a serious problem in connection with the installation of inflationary bags is the loss of gas through the sidewall of the pipeline when the bag or other restraining device is being installed. For example, ALH Systems, Inc. of Wiltshire, England manufactures and sells stop-off equipment including Gas Bags in which the bag is assembled around a flexible central inflation rod to discourage the bag from slipping along the interior of the pipeline under gas pressure once the bag has been inflated into the desired position. Such bags are satisfactory from the standpoint of sealing off the interior of the pipeline but do not avoid the risk of slipping or being blown downstream through the pipeline under gas pressure and thus not effectively seal the interior of the line.
U.S. Pat. No. 4,627,470 to Carruthers is directed more to the use of primary and secondary bags which are independently inserted into a pipeline to be repaired with the primary bag being inserted into position against a support disk and the secondary bag mounted directly against a column which is inserted through a hole in the pipe but does not address the problem of sealing off the wall of the pipe during the insertion of the bags, support disks and column and to adequately cap off the insertion holes once the job is completed. U.S. Pat. No. 4,428,204 to Brister discloses the use of a bag which is inserted through an insertion apparatus, and the bag is filled with water and frozen in place. U.S. Pat. No. 4,827,984 to Young et al utilizes an inflatable plug inserted into a pipeline but which is primarily designed for use in oil platform applications. U.S. Pat. No. 4,458,721 to Yie et al discloses an inflatable sleeve for restricting fluid flow in a pipeline using different forms of cartridges.
Notwithstanding the various approaches that have been taken in the past, there is a continuing need and demand for a novel and effective method and means for sealing off sections of a gas main and in which the gas main is sealed off from leakage or escape of gas throughout the entire operation beginning with the insertion of sealing devices into the line and concluding with removal of the sealing devices and particularly the inflation bags once the job is completed.
SUMMARY OF INVENTION
It is therefore an object of the present invention to provide for a novel and improved method and apparatus for sealing off conduits, such as, gas mains when the main is being serviced or repaired.
Another object of the present invention is to provide a novel and effective means for insertion of sealing devices into a gas main which will prevent escape or leakage of gas during the insertion phase of the operation; and further wherein the sealing devices may be effectively removed and the main permanently sealed off once it has been repaired or serviced.
It is a still further object of the present invention to provide in apparatus for sealing off gas mains and the like for a novel and improved restraining member to prevent slippage or movement of the sealing device within the line.
It is an additional object of the present invention to provide for a novel and improved apparatus for sealing off conduits, such as, gas mains and other pipelines which is of low-cost simplified construction, can be rapidly assembled and installed in a minimum number of steps and is reusable.
It is a yet another object of the present invention to provide for a novel and improved method for successive and independent insertion of a restraining element and inflatable sealing device into a gas main for the purpose of temporarily sealing off the main during its repair or service.
In accordance with the present invention, in the repair of a pipeline, such as, a gas main to be repaired or serviced there has ben devised first and second valve means disposed at diametrically opposed wall portions of the pipeline and in communication with the interior of the pipeline, a restraining rod inserted through the first and second valve means for extension across the interior of the pipeline, third valve means disposed in a wall of the pipeline at an angle to the first and second valve means and in communication with the interior of the pipeline, an inflatable bag member inserted through the third valve means into the interior of the pipeline, and inflation means for inflating the bag to fill the interior of the pipeline. Preferably, the third valve means is centered in the wall of the pipeline between the first and second valve means with the restraining rod extending at right angles to the direction of insertion of the inflatable bag member, and a flexible sealing means including a sleeve member is disposed on one side of the third valve means opposite to the wall of the pipeline whereby to temporarily seal off the third valve means against escape of any gas from the pipeline when the bag member is inserted through the third valve means.
In the method for repairing pipelines in accordance with the present invention, first and second holes are tapped into diametrically opposed sidewall portions of the pipeline, first and second valve members are positioned over the first and second holes and a rod inserted through the valve members diametrically across the interior of the pipeline and in sealed relation to the first and second valve members, a third hole is tapped in a wall portion of the pipeline spaced from the first and second holes, a third valve member mounted over the third hole in sealed relation to the wall portion of the pipeline, an inflatable bag inserted in deflated condition through the third valve member into the interior of the pipeline, and the bag inflated to fill the interior of the pipeline whereby to prevent the escape of gas past the bag. In order to prevent the escape of gas through the valve members when the rod and bag are inserted, a flexible sleeve is mounted on each valve member through which the rod or bag is inserted while maintaining sealed engagement between the rod or bag, as the case may be. Upon completion of the repair, the steps are reversed in removing the bag and restraining rod followed by permanently capping or sealing off the holes.
The above and other objects, advantages and features of the present invention will become more readily appreciated from a consideration of the following detailed description of a preferred embodiment thereof, when taken together with the accompanying drawings, in which:
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a view partially in section illustrating the installation of a preferred form of apparatus in accordance with the present invention;
FIG. 2 is a cross-sectional view illustrating in enlarged form the installation of a restraining rod assembly forming a part of the preferred form of the present invention;
FIG. 3 is a view partially in section of a dressing tool utilized in connection with carrying out the method of the present invention;
FIG. 4 is another cross-sectional view illustrating the final step of sealing the control fittings upon completion of a repair operation in accordance with the preferred method of the present invention; and
FIG. 5 is a view partially in section of a modified form of inflatable bag system to form a part of the apparatus of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring in more detail to the drawings, FIGS. 1 and 2 illustrate the mounting of a seal-off apparatus 10 in a pipeline P. The present invention may be best typified by describing its installation in a gas main composed of steel or cast iron wherein it is important to prevent the escape or leakage of gas both during installation of the apparatus 10 and subsequently during the repair or servicing of the main. Again, referring to FIGS. 1 and 2, the apparatus 10 is broadly comprised of a restraining rod 12 inserted through first and second valve members 14 and 15, the latter being mounted in diametrically opposed holes or openings 16 and 17 in outer wall W of the pipeline P. A third valve member 18 is disposed in a larger hole or opening 20 so as to be centered between and at right angles to the valve members 14 and 15. A flexible sleeve or sock 22 is secured to one side of the valve 18 opposite to the opening 20 to permit insertion of an inflatable bag 22, the bag 24 being inserted through the flexible sleeve 22 and open valve member 18 into the interior of the pipeline directly ahead or upstream of the restraining rod 12. An inflation line 26 is attached to a source of air under pressure designated at S in order to inflate the bag 24 into the condition as illustrated in full in FIG. 1, a pressure gauge G being positioned in the line to determine the pressure level in the bag.
Now considering in more detail the installation of the restraining rod 12, a control fitting or nipple 30 is welded to the exterior of the wall of the pipe and each of the openings 16 and 17 is tapped with a suitable tapping machine. Each valve 14 and 15 is threaded onto the nipple 30 and another nipple 32 is threaded into the outside of each valve. Although not shown, flexible sleeves identical in construction to the sleeve 22 but of a smaller diameter are secured or placed over the nipples 32 on the outside of each valve 14 and 15 to maintain the sealed engagement with the restraining rod 12 when it is inserted into the pipeline P. The restraining rod 12 is inserted through the diametrically opposed valve members 14 and 15, the rod having a handle or cap 33 at one end and a threaded end portion 34 at the opposite end. A rubber washer 35 and metal washer 36 are assembled onto each end of the rod 12, and a wing nut 40 is threaded onto the end 34 to securely tighten the washers 35 and 36 against the fittings 32 and tightly seal the valves 14 and 15 against the escape of any gas therethrough.
In order to install the valve 18, the larger hole 20 is tapped into the wall of the pipe P after a control fitting 42 has been welded to the exterior wall of the pipe, as shown in FIGS. 1 and 2. Another fitting 44 is threaded into the outside of the valve 18, the fitting 44 including diametrically opposed, radially extending handles 45. As best seen from FIGS. 1 and 3, the flexible sleeve or sock 22 has an enlarged generally tubular end portion 46 which is placed over the external end of the fitting 44 and sealed in place by means of a clamp or band 48. The sleeve tapers away from the enlarged end 46 as designated at 50 and terminates in an outer open end 51 which is of a diameter sufficient to permit insertion of the bag 24 in deflated condition through the sleeve 22, and the rod 12 will serve to guide the bag 12 into proper position. In the process of inserting the bag 24 through the sleeve and valve member 18, the tapered portion 50 may be grasped in the hand and folded tightly against the inflation line 26 to prevent the escape of any gas outwardly past the valve 18 and sleeve 22. Once the bag 24 is fully inserted into the line as illustrated in FIG. 1, any suitable form of tape or clamp 51' may be utilized to wrap and contract the outer end 51 of the sleeve into sealed engagement with the inflation line 26. Preferably, the sleeve 22 is composed of a non-porous rubber or rubber-like material, such as, Nylon. A smaller sleeve; i.e., one of lesser diameter but of identical construction and configuration to the sleeve 22 can be employed for installation and removal of the restraining rod in a manner to be described.
As a preliminary to insertion of the bag 24 into the main, a file is inserted through the sleeve 22 and open valve 18 to grind off any burrs or jagged edges around the hole 20. The file is removed and, as illustrated in FIG. 3, a dressing tool T having a wire brush W at one end is then inserted through the sleeve 22 and valve member 18 to dress the edge of the hole 20. In these filing and dressing operations, the tapered end 50 of the sleeve 22 can be grasped in the hand to seal the sleeve against the handle of the tool while manipulating it through the open valve member 18. In a similar manner, the sleeves that are employed for insertion of the restraining rod can be grasped in the hand to maintain sealed engagement with the rod as it is advanced through the valve members 14 and 15 with the washers 35 and 36 first assembled onto the handle end 33 of the rod; and, upon insertion, the washers 35 and 36 together with the wing nut 40 are assembled onto the threaded end 34 and the wing nut 40 tightened to seal the restraining rod 12 in position as described. Thereafter, the sleeves are removed from the fittings 32.
Preferably, the valve members 14 and 15 as well as the valve 18 are sandwich valves which can be manually opened and closed. For example, one suitable form of valve member 18 is a slide gate valve Model H-10917 manufactured and sold by Mueller Company of Decatur, Ill. The valves 14 and 15 are smaller than the valve 18 to accommodate the insertion of the restraining rod 12 which, for example, is typically on the order of 1/2" diameter. A preferred form of bag 24 is the gas bag manufactured and sold by ALH Systems, Inc. of Wiltshire, England and which is a reinforced nylon bag having an inner perforated inflation rod 25 terminating in a metal button 27 on the external surface of the bag and which will encourage the bag to slide along the bottom of the pipe as it is being inflated so that it does not become lodged against the inner wall surface of the pipe. When inflated, the bag 24 will expand into firm engagement with the restraining rod 12 which as described extends crosswise to the direction of insertion of the bag 24. The rod 12 will assist in guiding the bag 24 into position, as shown in FIG. 1; and, in the event of possible rupture of the bag, the rod 12 will prevent the bag 24 from becoming separated from the inflation line and becoming lost down the main.
It will be evident that one or more installations of the bag 24 and restraining rod 12 may be made at spaced intervals along the length of the pipeline. For instance, in repairing a section of the main, it is desirable to place a bag 24 and restraining rod 12 both upstream and downstream of the section to be repaired so as to completely block off the section from the leakage of gas. Once the installation is completed, the bag 24 is deflated, the wrapping 51' removed from the outer end of the sleeve 22 and the bag removed through the valve member 18 and sleeve 22. As shown in FIG. 4, the control fitting 42 is plugged off with an internal seal plug 54, following which the valve 18 is removed and a cap 55 threaded onto the external surface of the fitting 42. In a similar manner, the restraining rod 12 is removed by first unthreading the wing nut 40, advancing the rod through the valve 15, placing a plug 56 in the interior of the control fitting 30, removing the valve 15 and placing a cap 57 on the fitting 30. The same procedure is followed in withdrawing the rod from the valve 14 and sealing off its control fitting 30 with a plug 56 and cap 57.
In actual practice, when the bag 24 is to be installed in cast iron pipe, the control fittings 26 and 30 are welded to a split compression coupling which is placed over the pipeline, since the fittings cannot be welded directly to the pipeline. The valve member 18 is installed onto the fitting 26 and a conventional tapping machine is then attached to the valve 18; the valve 18 is opened and the pipe is tapped through the valve; and, once the tap is complete, the tapping cutters are retracted and the valve closed followed by removal of the tapping machine. The same procedure is followed in tapping holes for the restraining rod valves 14 and 15. In dressing the tap hole 20, the adapter sleeve 22 is attached to the valve 18 as described with a file positioned inside of the adapter. The valve 18 is opened to permit filing of the tap hole after which the file is removed and the valve closed. The dressing brush T is then inserted into the adapter sleeve 22 to brush any filings toward the downstream end, following which the brush is retracted and removed from the valve and the valve closed. The inflation bag 24 is then inserted into the sleeve 22 and the valve 18 is opened for insertion of the bag into the line. The bag is inflated to stop gas flow as required and, once the flow of gas is stopped, any gas remaining within the sock should be purged through an existing service or vent. Once the gas line is purged, the sleeve 22 can be removed.
DETAILED DESCRIPTION OF MODIFIED FORM OF INVENTION
As illustrated in FIG. 5, other types of inflation bags may be utilized in place of the bag 24 and, in FIG. 5, like parts are correspondingly enumerated to those of FIGS. 1 to 4. Thus, as in the preferred form, a control fitting 44' is attached to a valve member 18, not shown, and a sleeve adapter 22' of tapered conical configuration has its enlarged end 46' secured by a suitable clamp 48' to the outer end of the fitting 44'. A modified form of bag 60 is illustrated in deflated condition and differs from the bag 24 of FIG. 1 principally in the respect that it does not include any form of internal tubing or reinforcing, such as, the tubular element 25. In order to facilitate insertion of the bag 60, it is folded and secured to a guide rod 62 by means of suitable wraps, such as, the Velcro strips 64 at longitudinally spaced intervals along the bag 60. The wrapping 64 should be sufficient only to temporarily secure the bag to the reinforcing rod 62 in a compact deflated condition as shown to enable easy insertion through the valve and into the pipe with sufficient control over the bag 60 to insure that it is positioned upstream of the restraining rod. When the bag 60 is inflated, as described in conjunction with FIG. 1, the wrapping strips 64 will be severed as the bag is inflated to a degree sufficient to fill the line. The rod 62 will of course remain inside the pipe after the bag 60 has been inflated. Once the repair operation has been completed, the bag 60 is deflated as previously described in conjunction with the bag 24 and removed along with the rod 62 if the rod should still be attached to the bag; otherwise, the rod 62 will simply remain in the line and only the bag 60 withdrawn from the line. In all other respects, the installation and use of the bag 60 with a restraining rod 12 is the same as described in conjunction with FIGS. 1 to 4 of the preferred form.
It is therefore to be understood that while preferred and modified forms of apparatus are herein set forth and described together with the preferred method of the present invention, the above and other modifications and changes may be made without departing from the spirit and scope of the invention as set forth in the appended claims and reasonable equivalents thereof. | A method and apparatus for sealing off flow in a pipeline for the purpose of repairing the line includes a combination of a restraining rod and inflation bag which can be installed on either or both sides of the intended site of repair; and a flexible sleeve is provided for use in association with the entry ports and any associated valve members for insertion of the restraining rod and bag to prevent the escape of gas from the line during the insertion procedures. Once the line is repaired, the restraining rod and inflation bag can be removed and the entry ports completely sealed off. | 8 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a sheet cutter for cutting a sheet, particularly to one having a motor driven push cutter for cutting a portion of a continuous sheet discharged from a printer such as for hand held electric appliances.
2. Description of the Related Art
A role of paper used in a printer of some hand held electric appliances, such as a terminal register used in restaurants, is required to be cut bilaterally, namely, sometimes a printed part of the paper is cut off completely as a receipt for a customer and at other times a plurality of printed parts are cut incompletely between the successive printed parts as a series of receipts for a group of respective customers, the plurality of printed parts remaining connected by a central uncut part of narrow width. Each of the printed parts can be easily separated from each other by hand later on if every customer wants to have his. The former is often call full cut and the latter, half cut.
FIG. 1 is an exploded view of a main part of a prior art sheet cutter, and FIG. 2 is a front view of the main part of the prior art sheet cutter, which is looked at along an arrow indicated by a letter A. The sheet cutter 1 comprises a driving unit, or member, 11 mounted on a side wall of a chassis 1a, a rotating disc 12 assembled in the driving unit 11, a moving knife unit 13 making a moving knife 131 moved upwardly and downwardly by mounting both on the side wall of the chassis 1a and the rotating disc 12, and a stationary cutter unit 14 having a stationary knife 141 on it opposed to the moving knife 131. The driving unit 11 further includes a gear wheel 111 freely rotatable around a pivot P (i.e., an axle, or a shaft) mounted on a side wall of the chassis 1a, a worm gear 115 engaging with the gear wheel 111, and a driving motor 114 mounted on the side wall of the chassis 1a, a drive shaft of which is directly connected with an axle (i.e., a shaft) of the worm gear 115. Both a rotation pivot (i.e., shaft) 112, for the rotating disc 12, and a first sliding pin 113, restricting an angle of rotation of the rotating disc 12, are formed on respective peripheral positions of the gear wheel 111, projecting from an exposed side of the gear wheel 111. The rotating disc 12, having nearly the same diameter as that of the gear wheel 111, has a pivot bore 12a penetrated by the pivot 112 and an arcuate slit 12b for receiving therein and allowing the first sliding pin 113 to move therein, and which limits the angle of rotation of the rotating disc 12, and a second sliding pin 12c projecting from the exposed side of the gear wheel 111 into an elongated slot, or base, 123b of link arm 132 and which propagates driving forces to the moving knife unit 13. Thus, the rotating disc 12 is rotatable within the limited angle defined by the arcuate slit 12b, relatively to the gear wheel 111, when the rotating disc 12 is mounted on the gear wheel 111 by engaging the pivot 112 with the pivot bore 12a and the first sliding pin 113 with the slit 12b. The moving knife unit 13 comprises a moving knife 131 and the above-noted link arm 132, jointed with each other. The moving knife 131 has a vertical arm 131d on the upper side, an angle knife 131b with a setback area of a square notch 131a at the central region S on the lower side, and a pair of legs 131c. The link arm 132 has a pivot bore 132a on a first end engaged with a pivot 1a' protruding from the side wall of the chassis 1a and a long bore 132b engaged with the second sliding pin 12c of the rotating disc 12 on a second end. The link arm 132 is jointed with the moving knife 131 by a pin 132c (FIG. 2) at the upper end of the vertical arm 131d such that the link arm 132 is rotated around the pin 132c in a plane.
The stationary knife unit 14 comprises a knife stage 142 and a stationary knife 141 mounted on the knife stage 142, in which the stationary knife 141 is arranged in the foreground relative to the moving knife 131 in FIG. 1. The knife stage 142 has a narrow groove 142a into which the moving knife 131 is inserted. The narrow groove 142a has a pair of guiding portions 142b on both ends, which guide the respective legs 131c. A printed portion of continuous paper 15 is discharged through a gap between knife edges of the moving and stationary knives in the foreground direction indicated by a letter B.
FIGS. 3 and 4 are front views of the main part of a sheet cutter of a first prior art device, to explain full-cut and half-cut operations, respectively. In FIG. 3, the gear wheel 111 rotates clockwise about its axis, or pivot, P as indicated by a letter B 1 by the normal rotation of the motor 114, which causes a pivotal motion of the rotating disc 12 in the direction of an arrow as indicated by a letter C 1 by reactions from the first sliding pin 113 to the slit 12b and from the long bore 132b to the second sliding pin 12c. The reverse rotation of the motor 114 causes a counter clockwise rotation of the gear wheel 111 as indicated by a letter B 2 and then a pivotal motion of the rotating disc 12 in the direction of an arrow as indicated by a letter C 2 as shown in FIG. 4. Since a clockwise rotating radius R 1 of the rotating disc 12 is larger than a counter clockwise rotating radius R 2 , a down stroke of the moving knife 131 for clockwise rotation of the rotating disc 12 is longer than that for counter clockwise rotation of the rotating disc 12. The longer stroke of the moving knife 131 cuts off the discharged portion of continuous paper completely, while the shorter stroke cuts it incompletely by stopping the moving knife 131 such that the setback area of a square notch 131a at the central region on the lower side of the moving knife 131 shown in FIG. 1 is maintained above the upper surface of the paper. Therefore, the full-cut and half-cut of the paper can be carried out by selecting the normal and reverse rotations of the motor 114, respectively.
FIG. 5 is a front view of the main part of a prior art sheet cutter to explain a first drawback. The first drawback of the prior art is the fact that since the link arm 132 jointed with the moving knife 131 by the pin 132c is pivoted at 132a, a total force applied to the pin 132c denoted by a letter F 1 has a horizontal component of force when the moving knife 131 is pushed down. Therefore, the horizontal component of force causes an angular momentum in a plane including the moving knife which eventually often hinders the moving knife from moving down smoothly.
FIG. 6 is a front view of the main part of a prior art sheet cutter to explain a second drawback. The second drawback of the prior art is the fact that since the square notch 131a having a width denoted by a letter b at the central region on the lower side of the moving knife 131 has no sharp knife edge, a cross-section of the paper is not as sharply-cut in the fall-cut operation, wherein the cutting portion at the central region is protruded by a length corresponding to thickness of the knife edge denoted by a letter t from the other cutting portions in both sides 15a of the paper 15, and wherein, in the half-cut operation, the uncut portion having width 15b causes an irregular cutting shape when it is torn off by hand, which is not favorable in appearance.
SUMMARY OF THE INVENTION
An object of the present invention is to provide a sheet cutter including a pair of moving and stationary knives, in which the moving knife can move against a stationary knife smoothly along a pair of parallel cutter guides by pushing downwardly or pulling upwardly at two symmetrical points with the identical forces in parallel to the cutter guides, such that a total angular momentum on the moving knife around a gravitational center thereof vanishes (i.e., is nil).
Another object of the present invention is to provide a sheet cutter including a pair of moving and stationary knives, in which the moving knife has a thinner knife edge in the central part compared to the rest thereof, such that a cross-section of cut-off paper is smooth and clear-cut when the paper is cut off completely.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will be more apparent from the following description, when taken to conjunction with the accompanying drawings, in which:
FIG. 1 is an exploded view of the main part of a prior art sheet cutter.
FIG. 2 is a front view of the main part of the prior art sheet cutter.
FIG. 3 is a front view of the main part of a prior art sheet cutter to explain a full-cut operation.
FIG. 4 is a front view of the main part of a prior art sheet cutter to explain a half-cut operation.
FIG. 5 is a front view of the main part of a prior art sheet cutter to explain the first drawback.
FIG. 6 is a front view of the main part of a prior art sheet cutter to explain the second drawback.
FIG. 7 is an exploded, perspective view of a main part of a sheet cutter of a first embodiment according to the present invention.
FIG. 8 is a front view of the main part of the sheet cutter shown in FIG. 7 according to the present invention.
FIG. 9 is a front view of the main part of the sheet cutter shown in FIG. 7 to explain a full-cut operation.
FIG. 10 is a front view of the main part of the sheet cutter shown in FIG. 7 to explain a half-cut operation.
FIG. 11 is a perspective view of a main part of a sheet cutter of a second embodiment according to the present invention.
FIG. 12 is an enlarged side view of the moving and stationary knives of the sheet cutter shown in FIG. 11.
FIG. 13 is a perspective view of the main part of a sheet cutter for the third embodiment according to the present invention.
FIG. 14 is an enlarged bottom view of the center part of the moving knife of the sheet cutter shown in FIG. 13.
FIG. 15 is an enlarged front view of the center part of the moving knife of the sheet cutter shown in FIG. 13.
FIG. 16 is an exploded view of a main part of a sheet cutter of a fourth embodiment according to the present invention.
FIG. 17 is a front view of the main part of the sheet cutter shown in FIG. 16 to explain a half-cut operation.
FIG. 18 is a schematic top view of a pair of convex moving and flat stationary knives of a fifth embodiment according to the present invention.
FIG. 19 is a schematic top view of a pair of V-shaped moving and flat stationary knives of a sixth embodiment according to the present invention.
FIGS. 20 and 21 are front view of moving knives having setback areas of various shapes according to the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Reference will now be made in detail to the preferred illustrated embodiments of the invention, examples of which are illustrated in the accompanying drawings. While the invention will be described in conjunction with the preferred illustrated embodiments, it will be understood that they are not intended to limit the invention to these embodiments. On the contrary, the invention is intended to cover alternatives, modifications and equivalents, which may be included within the spirit and scope of the invention as defined by the appended claims.
Common reference numbers and symbols are used throughout figures below whenever mechanical parts or functions are same.
FIGS. 7 and 8 are an exploded, perspective view and a front view, respectively, of the main part of a sheet cutter of a first embodiment according to the present invention, in which FIG. 8 is viewed in the direction of an arrow denoted by a letter A shown in FIG. 7.
A sheet cutter 2 shown in FIG. 7 comprises a driving unit 21 mounted on a side wall of the chassis 2a, a pair of link arms 22 connected with the respective gear wheels 211, 215 (described later) which are components of the driving unit 21, a moving knife 23 connecting with the link arms 22, and a cutter unit 24. The cutter unit 24 comprises a stage 242 having a pair of parallel guides 242a for guiding the moving knife 23 to slide upwardly or downwardly, a stationary knife 241 opposing to the moving knife 23, and a narrow groove 242b for receiving the pair of legs 131c of the moving knife 23. The driving unit 21 comprises a driving motor 213 secured to the side wall of the chassis 2a with a shaft extending parallel to the side wall having a worm gear 214 on an end portion of, and so as to rotate with, the shaft, a worm gear 211 with a shaft attached to the side wall rotated by engaging with the worm gear 214, and a pair of identical gear wheels 212 and 215 engaged with each other, the first one 212 being fixed to the worm gear 211 with the same axis (i.e., shaft) as that of the worm gear 211 and the second one 215 being rotatable in the same plane as that of the first one 212 with a shaft attached to the side wall. The first and second gear wheels 212, 215 have respective pivots 212a, 215a and respective pairs of stoppers 212b -1 , 212b -2 , and 215b -1 , 215b -2 projecting out of the exposed sides of the gear wheels, respectively. Each of the link arms 22 has a through hole at one end into which the respective one of the pivots 212a, 215a is inserted. The pivots 212a and 215a are located in the neighborhood of the respective periphery of the gear wheels 215 and 215, respectively. Each pair of the stoppers 212b -1 , 212b -2 and 215b -1 , 215b -2 limits the respective rotating angle of the link arms 22, respectively. The stoppers 212b -1 , and 215b -1 are located in the neighborhood of the respective centers of the gear wheels 212 and 215, respectively, while the stoppers 212b -2 and 215b -2 are located in the neighborhood of the respective peripheries of the gear wheels 212 and 215, respectively. Each of the link arms 22 15 is connected at a first end to, and is rotatable around, the respective one of the pivots 212a, 215a, and has a pin 22b projecting out of the exposed side at the second end of each thereof, which is inserted into the respective one of a pair of horizontally extended slits 23a in the moving knife 23. The horizontally extended slits 23a in the moving knife 23 are located symmetrically to each other with respect to the vertical axis passing through the gravitational center of the moving knife 23, below the upper side 23c (FIGS. 7 and 8) of the moving knife 23 by a distance denoted by a letter a (FIG. 7), and having an identical length on both sides, which is long enough to cover the horizontal maximum moving range of the pins corresponding to the overall range of the limited rotating angle. In this configuration, when the motor 213 drives the worm 214, rotation of the worm 214 causes a normal (i.e., forward) rotation of the gear wheel 212 and the reverse rotation of the gear wheel 212 through the worm gear 211. Rotation of both the gear wheels gives rise to sliding both pins 22b along the horizontally extended slits 23a on the moving knife 23, symmetrically to each other with respect to the vertical axis passing through the gravitational center of the moving knife 23. Consequently, the symmetrical horizontal motion of both pins 22b makes the moving knife 23 move upwardly or downwardly, depending upon a rotating direction of the motor 213. It should be noted that since the pins move symmetrically to each other, the moving knife 23 moves upwardly or downwardly smoothly along the pair of parallel guides 242a. This is because the horizontal components of the forces exerted on the slits 23a by the respective pins always cancel out each other, and only the vertical components of the forces are exerted on the slits in parallel to the pair of guides 242a. In other words, there is no net angular momentum around the gravitational center of the moving knife during vertical movements of the moving knife. Thus, this structural feature results in smooth vertical movements of the moving knife.
Another structural feature according the present invention are that the moving knife 23 has an asymmetric knife edge 23b which consists of two knife edges, both inclined relatively to the stationary knife edge 241, and that one knife edge is slightly longer than the other. Since this knife edge has a setback area of a triangular shape 231 in the central region (shown in FIG. 8 as a shaded area) and which is inclined relatively to the stationary knife edge 241, the uncut region 15b of the paper for the half-cut can be left with a larger allowable error in the stroke of the moving knife than that of the moving knife having no setback area, such as a simple inverse V-shape knife edge, and that the whole paper can be cut off with a clear-cut cross-section for the full-cut.
The inclined knife edge in the setback area gives another favorable effect, in that the uncut region 15b shown in FIG. 6 can be chosen to be any desired width by adjusting the stroke of the moving knife, which can leave a better shape of a rupture pattern by narrowing the width of the uncut region 15b as desired for the half-cut when the uncut region 15b is torn by hand. The setback area 231 according to the present invention generally has an inclined upper side 231a. FIGS. 20 and 21 are some modified cases for the setback area. Either one can pronounce the beneficial effects similar to the moving knife shown in FIG. 8.
FIGS. 9 and 10 are front views of the main part of the sheet cutter shown in FIG. 7 to explain full-cut and half-cut operations, respectively.
In FIG. 9, the motor 213 rotates the worm gear 214 in the direction of an arrow denoted by a letter C, and then rotates both the worm gear 211 about its axis and the first gear wheel 212 clockwise about its axis, or pivot, P3 as indicated by an arrow denoted by a letter C 1 , which produces an accompanying counter clockwise rotation of the second gear wheel 215 as indicated by an arrow denoted by a letter C 2 . Eventually, both the link arms 22 rotate in mutually opposite directions indicated by arrows C 1 ' and C 2 ', to relatively to each other and to the directions of C 1 and C 2 of to the first and second gear wheels 212, 215, respectively. Therefore, the first and second gear wheels 212, 215 rotate under conditions that (i.e., to a limit at which) the link arms 22 come into contact with the respective stoppers 212b -2 and 215b -2 , respectively.
On the other hand and as shown in FIG. 10, when the motor 213 rotates the worm gear 214 together in the direction of an arrow denoted by a letter C' (FIG. 10), the first gear wheel 212 with the worm gear 211 rotate counter clockwise, as indicated by an arrow denoted by a letter C 3 and then the second gear wheel 215 rotates clockwise as indicated by an arrow denoted by a letter C 4 as shown in FIG. 10. Consequently, the first and second gear wheels 212, 215 rotate about respective thin respective prints P3 in the respective, relatively opposite C 3 ' and C 4 ' directions under conditions that (i.e., to a limit at which) the respective link arms 22 contact the respective stoppers 212b -1 and 215b -1 , respectively. The rotating radii R 3 , R 4 of the link arms 22 are defined by distances between the center of the first gear wheel 212 and the pin 22b for the clockwise and counter clockwise rotations of the first gear wheel 212 as shown in FIGS. 9 and 10, respectively, wherein the rotating radius R 3 is larger than the rotating radius R 4 . This is because the stoppers 212b -1 and 215b -1 are located in the neighborhood of the respective rotating centers of the first and second gear wheels 212, 215, respectively, while the stoppers 212b -2 and 215b -2 are located in the neighborhood of the respective peripheries of the first and second gear wheels 212, 215, respectively. The difference in radius results that the vertical stroke of the moving knife in FIG. 9 is longer than that in FIG. 10. Therefore, it is possible that the longer stroke as shown in FIG. 9 is applied to the full-cut of the paper, and the shorter stroke as shown in FIG. 10 is applied to the half-cut by optimizing the position of the stationary knife against the moving knife. In other words, the full-cut and half-cut operations can be determined by selecting a rotating direction of the motor 213.
FIGS. 11 and 12 are a perspective view of the main part of a sheet cutter for the second embodiment according to the present invention and an enlarged side view of the moving and stationary knives viewed along the direction denoted by a letter B shown in FIG. 11, respectively.
The cutter unit 31 for the second embodiment can be obtained by mounting the stationary knife 241 on the stage 242 with an inclination of the angle θ, which may be smaller than 45 degrees, to the moving knife such that only an edge 241a' of the upper side 241a has contact with the moving knife 23 in the cross-section as shown in FIG. 12. The cutter unit 31 has line contact between the flat moving and stationary knives instead of an area contact in the prior art (in which θ=0°); as a result, a stress on the linear contact area between the flat moving and stationary knives is much less than that on the surface area contact of the prior art, and which improves cutting performance. Needless to say, the flat moving and stationary knives are easy to fabricate and less expensive. When the inclination of an angle θ was chosen about three degree (θ=3°), the cutting performance was improved considerably without an appreciable wear of the knife edges.
If further improvement in cutting performance is desired, it can be done by providing a pair of moving and stationary knives one of which is bent against another when it is seen from the top position. For instance, FIG. 18 is a schematic top view of a pair of convex moving knife 232 and a flat stationary knife 242 with contact points Q, Q', while FIG. 19 is a schematic top view of a pair of V-shaped moving knife 233 and a flat stationary knife 243 with contact points Q, Q'. Curvature and bending angle of both the moving knives are exaggerated for illustration. In either case, the moving knife always keeps contact with the respective flat stationary knife only at symmetrical two points Q, Q' on the knife edges during the whole cutting process. In other words, the stress is always concentrated on the two points Q, Q' just at which the paper is cut. The cutting starts at both sides of a sheet of paper, then cutting points approach to each other, and finally the two points get together (i.e., connect, or join) at the central part when the paper is cut off completely.
FIG. 13 is a perspective view of the main part of a sheet cutter of the third embodiment according to the present invention. FIGS. 14 and 15 are enlarged bottom and front views of the center part of the moving knife shown in FIG. 13.
The moving knife 41 has a recessed area on the back side 41a in the central region indicated by T. The recessed surface 41b is sunken, or recessed relatively to, from the back side 41a by depth of t--t' where t' and t are respective thicknesses of the central region indicated by T and that of the rest of the moving knife, respectively. The moving knife having the recessed area in the central region improves a cutting cross-section for full-cut case and makes a width of the uncut-region 15b narrower for the half-cut, thereby to leave a better appearance for the torn portion. As an example, when t and t' were chosen to be 0.8 mm and 0.3 mm, respectively, an appearance of the torn portion was remarkably improved without any degradation of mechanical strength in the moving knife.
FIGS. 16 and 17 are exploded, perspective and front views, respectively, of the main part of a sheet cutter 5 of a fourth embodiment according to the present invention.
The sheet cutters of the fourth embodiment comprises a driving unit 51 and a cutter unit 24. The former is essentially the same as the unit 21 of the first embodiment 2 shown in FIG. 7 except that a pair of the gear wheels 212, 215 with respective stoppers are replaced by a new pair of identical gear wheels 511, 512. Namely, the first gear wheel 511 has a sector-shaped groove 511a into which a link arm 22 is sunken, to undergo a pivotal motion around a pivot 511b, while the gear wheel 512 has a sector-shaped groove 512a into which a link arm 22 is sunken to undergo a pivotal motion around a pivot 512b. Both the link arms 22 are limited their pivotal motion within, the respective sector-shaped grooves. Particularly, each pair of side walls in the sector-shaped grooves acts as a pair of stoppers for the respective link arm 22. The resultant benefits of this embodiment are to save the space between the side wall and the cutter, and to simplify the manufacturing process of the cutter unit such that it is easier to make the gear wheel having a sector-shaped groove than that having a pair of stoppers such as 212b -1 , 212b -2 . These advantages provide a sheet cutter which is smaller and less expensive than that of the prior art. | A sheet cutter cuts a portion of a continuous sheet, discharged through a gap between a pair of moving and stationary knives respectively having arc-shaped and straight knife edges. A motor rotates a pair of rotatable, identical gear wheels engaged with each other and opposed to the moving knife and having a pair of respective link arms thereon. Each link arm has a first end connected to a peripheral position of the respective gear wheel by a pivot thereon and a second end connected to the moving knife by a pin inserted into a respective one of a pair of horizontally extending slits in the moving knife. Rotating motion of the gear wheels is transformed into a reciprocating motion of the moving knife against, and relatively to, the stationary knife, in which the second end of each link arm assumes one of two opposing positions, depending respectively upon a current one of opposite rotating directions of the respective gear wheel, such that one or the other rotating direction of the motor results in the reciprocating motion of the moving knife with a stroke either to cut the sheet completely or incompletely. | 8 |
BACKGROUND OF THE INVENTION
[0001] The invention relates to a retention system used to prevent axial movement of a turbine bucket dovetail in a corresponding dovetail slot in a turbine rotor wheel, and more specifically, to techniques for preventing circumferential rotation of the axial retention system. This retention system typically takes the form of a lockwire within an annular slot or groove in the turbine rotor wheel.
[0002] In conventional turbine and/or turbine compressor components, buckets (or blades, or airfoils) are held in a rotor wheel by means of a slotted connection, e.g., a so-called “fir tree” or “Christmas tree” arrangement where an inwardly-tapered male connector portion at the radially inner end of the bucket is received in a complementary female slot in the rotor wheel. Such connections are also generically referred to as “dovetail” connections, embracing various complementary shapes which lock the buckets to the wheel in the radial and circumferential directions so as to accommodate the high centrifugal forces generated by rotation of the turbine rotor.
[0003] The fit between the blade dovetail and the dovetail slot is sufficiently loose to allow for assembly and tolerances. Centrifugal loading above a certain threshold speed effectively locks up the bucket in the wheel due to the contact forces and friction. However, operation at low speed, during which the blades are able to rock inside the dovetail, can have the tendency to make the blade move along the dovetail in the absence of axial retention. If the blade is not properly retained, the eventual likely outcome is a collision with neighboring stationary components. Before such collision can take place however, the axial movement along the dovetail could effectively block cooling flow into the blade. In the absence of the cooling flow, oxidation erosion will wear away the leading edge of the blade. An additional consequence, therefore, is unplanned machine down-time and maintenance resulting from varying degrees of machine performance deterioration up to blade separation and resulting collateral or domestic object damage.
[0004] In accordance with usual design practice, the buckets or blades are prevented from moving axially in the dovetail slots provided in the rotor wheel by a retention device, hereafter called a “lockwire”, passing through an annular slot formed in the radially outer periphery of the wheel and passing through circumferentially-aligned slots in the dovetail portions of the respective buckets. The free ends of the wire are shaped so that they come together at an overlapped joint, thus allowing for minor changes in length and diameter of the lockwire as the rotor wheel, rotor wheel slots and buckets expand and contract during transient periods. The lockwire is held in place by the radial spring force stemming from installation of a relatively larger-diameter lockwire in a relatively smaller-diameter annular slot, and pins mounted in the turbine wheel, radially inwardly of the lockwire. It has been discovered that rotation of the lockwire within the annular slot in the rotor wheel (which occurs over time) can cause the free ends of the lockwire to separate at the overlap joint so that one end of the lockwire may engage a pin and bend downwardly (radially inwardly) below the pin and, thus permit the lockwire to escape the annular slot.
[0005] Without the lockwire, the airfoils are free to travel axially along the dovetail slots, creating the potential for excessive wear and interference as mentioned above. In addition, this is especially consequential in first and second stage buckets that rely on holes in the base of the bucket to provide internal cooling. When these holes are blocked due to axial movement of the bucket, cooling air cannot reach the target area and the bucket can quickly oxidize along the leading edge.
[0006] There remains a need for a reliable technique for preventing circumferential rotation of the lockwire within its annular slot to thereby prevent escape of the lockwire from the rotor wheel by preventing rotation of the lockwire.
BRIEF DESCRIPTION OF THE INVENTION
[0007] In one exemplary but nonlimiting embodiment, the invention relates to a retention system for a plurality of turbine buckets located in respective mating slots in a turbine rotor wheel, the retention system comprising a plurality of first circumferentially-oriented retention slots formed in outer peripheral portions of the turbine wheel; a plurality of second circumferentially-oriented retention slots formed in wheel mounting portions of the buckets, the first and second retention slots aligned to form an annular lockwire retention slot; a lockwire located within the annular lockwire retention slot, the lockwire having free ends; a first surface feature on one or both of the turbine rotor wheel and one or more of the plurality of turbine buckets; and a second surface feature on the lockwire adapted to engage with the first surface feature on one or both of the turbine rotor wheel and one or more of the plurality of turbine buckets for preventing circumferential rotation of the lockwire beyond predetermined limits.
[0008] In a second exemplary but nonlimiting embodiment, the invention relates to a retention system for a plurality of turbine buckets located in respective mating slots in a turbine rotor wheel, the retention system comprising a plurality of first circumferentially-oriented retention slots formed in outer peripheral portions of the turbine wheel; a plurality of second circumferentially-oriented retention slots formed in wheel mounting portions of the buckets, the first and second retention slots aligned to form an annular lockwire retention slot; a lockwire located within the annular lockwire retention slot, the lockwire having free ends; at least one axially-oriented surface feature provided on the rotor wheel or on one or more of the plurality of buckets for holding the lockwire in the annular retention slot; and at least one radially extending surface feature on the lockwire engageable with the at least one axially-oriented surface feature for preventing circumferential rotation of the lockwire beyond predetermined limits.
[0009] In still another nonlimiting aspect, the invention relates to a retention system for a plurality of turbine buckets located in respective mating slots in a turbine rotor wheel, the retention system comprising a plurality of first circumferentially-oriented retention slots formed in outer peripheral portions of the turbine wheel; a plurality of second circumferentially-oriented retention slots formed in wheel mounting portions of the buckets, the first and second retention slots aligned to form an annular lockwire retention slot; a lockwire located within the annular lockwire retention slot, the lockwire having free ends; at least one surface feature provided on the rotor wheel or on one or more of the plurality of buckets for holding the lockwire in the annular retention slot; and at least one axially-extending surface feature on the lockwire engageable with the at least one surface feature on the rotor wheel or on one or more of the plurality of buckets for preventing circumferential rotation of the lockwire beyond predetermined limits.
[0010] The invention will now be described in detail in connection with the drawings identified below.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] FIG. 1 is a partial top perspective view of a known turbine rotor wheel and bucket assembly showing a lockwire in place;
[0012] FIG. 2 is a partial bottom perspective view of the rotor wheel and bucket assembly shown in FIG. 1 ;
[0013] FIG. 3 is a partial elevation view of overlapped free ends of a lockwire;
[0014] FIG. 3A is similar to FIG. 3 but illustrates an alternative lockwire design formed with tapered free ends;
[0015] FIG. 4 is a schematic representation of separated free ends of a lockwire, with one end trapped below a retaining pin;
[0016] FIG. 5 is a partial perspective view of an annular lockwire fitted with radially-inwardly extending anti-rotation tabs in accordance with an exemplary but nonlimiting embodiment of the invention;
[0017] FIG. 5A is a schematic view of an alternative, nonlimiting lockwire configuration where a local deformation serves as an anti-rotation tab;
[0018] FIG. 6 is a partial perspective view of a rotor wheel with the lockwire of FIG. 5 installed;
[0019] FIG. 6A is a partial elevation in transparent format, illustrating an alternative but nonlimiting embodiment where the anti-rotation tabs extend radially outwardly of the lockwire;
[0020] FIG. 7 is a perspective view of a lockwire fitted with axially-extending anti-rotation tabs in accordance with another exemplary but nonlimiting embodiment of the invention; and
[0021] FIG. 8 is a partial perspective view of the lockwire of FIG. 7 installed within a bucket lockwire slot.
DETAILED DESCRIPTION OF THE INVENTION
[0022] FIGS. 1 and 2 illustrate one technique for preventing axial movement of a turbine bucket received within a slot in a turbine rotor wheel. More specifically, the turbine rotor wheel 10 is formed with a plurality of dovetail slots 12 about the entire outer periphery of the wheel, each dovetail slot 12 receiving a complementary dovetail portion 14 of a bucket or blade 16 (only three complete slots and one bucket shown in the Figures). It will be understood that the bucket or blade 16 is of conventional construction, including a shank portion 18 , an airfoil portion 20 and the dovetail portion (or simply, dovetail) 14 .
[0023] The radially projecting portions 24 of the wheel which define the slots 12 are formed with first lockwire slots 26 , each closed at its radially outer end 28 and open at its radially inner end 30 . The first lockwire slots 26 are formed adjacent to one side of the wheel, and together, form an annular 360° slot about the periphery of the wheel, interrupted by the dovetail slots 12 . Axially offset portions (or lock tabs) 32 of the bucket dovetails 14 define a plurality of second lockwire slots 34 that are alignable with the first lockwire slots 26 upon introduction of the buckets 16 into the dovetail slots 12 . A lockwire 36 (preferably a suitable metal alloy) may then be introduced into the aligned lockwire slots 26 , 34 with free ends 38 , 40 shaped (e.g., reduced to a semi-circular cross section) to smoothly overlap each other along opposed surfaces 39 , 41 in a normally-installed condition ( FIG. 3 ), recognizing that the opposed surfaces are substantially flat when the lockwire is uncoiled and arcuate when installed in the annular slots 26 , 34 . The lockwire itself may be a single strand or multiple connected or overlapping segments. Axially-oriented retaining pins 42 inserted through the portions of the rotor wheel 10 are employed to hold the lockwire 36 within the lockwire slots 26 ( FIGS. 1 and 2 ).
[0024] FIG. 4 illustrates a problem experienced with the lockwire configuration as described above. Specifically, it has been found that the lockwire 36 is prone to circumferential rotation during turbine operation due perhaps to thermal and/or mechanical ratcheting. Resulting separation of the free ends 38 , 40 of the lockwire can result in one end (the trailing end in the direction of lockwire rotation) travelling below (i.e., radially inwardly) of one of the pins 42 so that during lockwire rotation in the direction shown by arrow 44 , the lockwire 36 may escape the lockwire slots 26 , 34 , thereby permitting axial movement of the buckets 16 within the dovetail slots 12 .
[0025] FIGS. 5 and 6 illustrates an exemplary but nonlimiting embodiment of a lockwire 46 (or other equivalent surface feature) provided with radially inwardly extending tabs 48 for substantially preventing excessive circumferential rotation of the lockwire 46 when installed in the lockwire slots 26 , 34 ( FIG. 6 ), as described further below. The end result is that the inner and outer free ends (similar to free ends 38 , 40 in FIG. 3 but not shown in FIG. 4 ), of the lockwire 46 are prevented from excessive circumferential rotation which might otherwise lead to one free end moving below or radially inward of the retaining pins 42 as shown in FIG. 4 .
[0026] The lockwire 46 , like the lockwire 36 , may have a round cross section with an appropriately chosen diameter, and the free ends 36 , 38 are each also reshaped to a smaller cross section (e.g., semi-circular) than the remaining major length of the lockwire to provide an overlap region of substantially the same profile as the remainder of the lockwire, with the free ends engaged along opposed substantially flat, circumferentially (or horizontally)-oriented surfaces as shown in FIG. 3 . The opposed surfaces at the overlap may also be wedge-shaped or tapered as shown at 39 A and 41 A in FIG. 3A . The ends of the lockwire 46 may also be formed on a slightly larger diameter than the remainder of the lockwire, which is otherwise formed to substantially match the diameter of the lockwire slot. This results in a tighter engagement of the overlapped free ends.
[0027] The lockwire 46 may also be formed with other cross-sectional shapes such as oval, elliptical, semi-circular or other suitable shape.
[0028] The lockwire 46 is provided with at least one and preferably between 2 and 4 or more of the radially extending tabs 48 having thicknesses less than the diameter of the lockwire. For example, lockwire diameters of 0.188″, 0.250″, and 0.300″ may have tab thicknesses of substantially half the given diameters. The length, width, thickness and shape of the tabs 48 (or other functionally equivalent surface features added to the lockwire) may vary depending on specific applications as dictated by the available space or load carrying capability required by the intended application. In most cases, the size of the tabs 48 (or other surface features) will be the minimum size that performs the desired function, i.e., stopping any undesirable (i.e., excessive) circumferential rotation of the lockwire by engagement of the tabs (or other surface features) with respective, next-adjacent retaining pins.
[0029] The anti-rotation tabs 48 are preferably welded or brazed to the lockwire, but the invention is not limited to any particular securement or forming technique. For example, the tabs 48 or other surface features may be attached to the lockwire by casting, forging, welding, brazing, or by any other suitable mechanical attachment. The tabs may also be in the form of sheet material bent about the lockwire and secured by any of the above techniques. The tabs may also be machined or otherwise made integral with the wire. The “tab” may also be formed by one or more local deformations in the lockwire. One example is shown in FIG. 5A , where a bend 47 creates a tab 49 that will engage the pin 42 in a manner similar to the tab 48 . In addition, the number and location of the tabs (or other surface features) relative to the retaining pins may vary. For example, FIG. 4 shows a retaining pin 42 circumferentially between a pair of radially inwardly extending tabs 48 so that rotation in either direction will be halted when the pin 42 is engaged by one of the tabs 48 . While some rotation of the lockwire is permitted to accommodate, for example thermal growth, circumferential rotation beyond predetermined limits is prevented. It is also possible to mount the tabs 48 such that two tabs 48 lie, respectively, on opposite sides of two adjacent pins 42 (see the dotted line pins 142 to the outside of adjacent tabs 48 ). The number of tabs 48 (or other surface features) on the lockwire may vary between one and more than four, but it is preferable (but not required) that the tabs or other surface features be located substantially mid-way between the free ends of the lockwire. In addition, the pins 42 need not be of the shape illustrated in the drawings. Other axially extending surface features on the rotor wheel or in the buckets may be used to engage one or more of the tabs 48 or other surface features on the lockwire to prevent circumferential rotation of the lockwire.
[0030] It will be appreciated that the tabs 48 (or other surface features) may also extend radially outwardly of the lockwire, as illustrated, for example, in FIG. 6A . FIG. 6A is a transparency showing a tab 48 A extending radially outwardly of the lockwire 46 A, and received in an opening 50 formed in the dovetail portion 52 of the bucket 54 .
[0031] It is also within the scope of the invention to have axially extending tabs or other surface features on the lockwire that, upon minimal rotation of the lockwire, will engage a hole or slot or other surface feature formed in the adjacent slot wall of the bucket or turbine wheel. For example, FIG. 7 illustrates a lockwire 56 provided with one or more axially-extending tabs 58 sized, shaped and located to engage a hole, slot or other surface feature provided in the rotor wheel or bucket. FIG. 8 shows one example where the lockwire 56 of FIG. 7 is installed in the annular groove 60 (shown only with respect to the single bucket 62 ) such that the axially-extending tab 58 is loosely received within a radially extending slot 64 formed in the bucket dovetail 66 that opens into the annular groove 60 . In this way, the lockwire 56 is prevented from excessive circumferential rotation that might otherwise allow escape of the lockwire 56 from the annular slot or groove 60 . It will be appreciated that the axially-extending tab (or other surface feature) 58 may also vary in size, shape and number as described above in connection with the tab(s) 48 , and that the tab 58 may extend axially from either side of the lockwire depending on the location of a hole, groove, notch or other surface feature within the annular or circumferential slot or groove 60 in the bucket (or turbine wheel) with which it cooperates to prevent circumferential rotation of the lockwire.
[0032] In all cases, the amount of lockwire rotation is limited to the extent that separation of the overlapped free ends of the lockwire is precluded.
[0033] While the invention has been described in connection with what is presently considered to be the most practical and preferred embodiments, it is to be understood that the invention is not to be limited to the disclosed embodiments, but on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims. | A retention system for a plurality of turbine buckets located in respective mating slots in a turbine rotor wheel includes a plurality of first circumferentially-oriented retention slots formed in outer peripheral portions of the turbine wheel; a plurality of second circumferentially-oriented retention slots formed in wheel mounting portions of said buckets, the first and second circumferentially-oriented retention slots aligned to form an annular lockwire retention slot; and a lockwire located within the annular lockwire retention slot. A first surface feature on one or both of the turbine rotor wheel and one or more of said plurality of turbine buckets is adapted to engage a second surface feature on the lockwire for preventing rotation of the lockwire beyond predetermined limits. | 5 |
This invention relates to a self-responsive fluid means for anti-cavitation, and, more particularly, it relates to a fluid means wherein a fluid system of a pump and a valve and a motor have an additional valve which directs the exhaust flow from the motor back to the other said valve and then to the motor itself, under certain conditions of operation.
BACKGROUND OF THE INVENTION
The prior art is aware of various fluid systems for directing fluid flow to and from fluid motors, and it is also aware of various arrangements of fluid valves for the purpose mentioned. Prior U.S. patents which show some type of hydraulic system are Nos. 2,386,291 and 2,423,264 and 2,466,485 and 3,370,602. These patents only show arrangements of hydraulic or fluid systems which employ a driven member or motor and a valve for controlling flow thereto, and the last three patents mentioned also show a pump and an equalizing or diverter valve in addition to a type of control valve in the system.
The prior art also reveals various arrangements for fluid valves, such as seen in U.S. Pat. Nos. 2,593,185 and 2,971,552 and 3,060,953 and 3,200,830 and 3,437,103 and 3,554,213 and 3,590,844 and 3,722,524 and 3,924,650. These patents all show various arrangements for valves having spools serving as closure members and with the spools being responsive to the fluid pressure within the valve itself. However, these valves are fundamentally only flow divider valves where flow will enter the valve in one opening and will leave the valve through two other openings. In that regard, the latter three of the first aforesaid group of patents also show divider valves, and U.S. Pat. Nos. 2,466,485 and 3,370,602 particularly show spools with end faces thereon disposed in separated chambers within the valve body and having passageways leading to the chambers, all for shifting the spool according to fluid pressure on those spool faces. However, those are still only diverter valves, rather than a combiner type of valve which, as in the present instance, takes fluid from two sources and combines it in an outlet flow. As such, this is the advantage and object of the present invention.
However, U.S. Pat. No. 3,437,103 can be used as a combiner type of valve where the fluid is taken from two sources and combines it into one outlet. Nevertheless, that prior art does not disclose a combiner wherein a fluid is accepted from two sources and combined at some flow proportion to an outlet, and thus it does not select fluid from one of two sources to direct it to the desired outlet or user system. As such, the present invention has as its object the provision of a valve which receives fluid from two sources and, at some proportionate pressure or flow between the two sources, the valve reacts to direct the flow from one source and to direct only it to the user system. Further, this invention has as its objective the accomplishment of the aforementioned improvements by utilization of simplified apparatus, such as the self-responsive selector valve mentioned, which is readily and easily inserted into a fluid system of a pump, a control valve and a fluid motor.
Still further, it is an object and advantage of this invention to provide apparatus wherein a self-responsive valve is incorporated in a system and arranged so that when the powered element of the system requires excessive fluid, the valve will react and in essence re-cycle the fluid through the powered element or apparatus itself. Simultaneous with that action, the self-responsive valve of this invention will divert the flow from the supplying pump and to the reservoir. Therefore, the apparatus of this invention is particularly useful in situations such as vehicle transmissions, and particularly tractor transmissions where, for instance, when the tractor is running downhill and the transmission is thus driven through that type of movement, the fluid motor arranged with the transmission will cause excessive flow of the fluid, and that fluid can be diverted through the valve employed herein and back to the driven motor itself, to thus avoid anti-cavitation of the system. When the cavitation of the drive motor of the aforementioned system occurs, complete loss of vehicle or tractor speed control results, and thus the apparatus of this invention is utilized to avoid that uncontrolled condition. Some of the prior art attempts to solve this problem result in an arrangement where there is only one available downhill tractor speed, or there may be an arrangement for excessive loading of the engine itself, or there may be an arrangement to provide for only a short time duration of downhill control. However, the present invention provides for the complete and self-responsive control of the tendency for the system to cavitate, as mentioned.
Other objects and advantages will become apparent upon reading the following description in light of the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic view of an entire fluid system arranged according to this invention.
FIGS. 2, 3, and 4 are enlarged sectional views of one of the valves shown in the system in FIG. 1.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 shows the fluid system which includes a supply or reservoir 10, a fluid pump 11, a fluid motor or driven member 12, and a fluid valve 13 and a fluid valve 14. The aforesaid elements are all inter-connected with the fluid lines therebetween, as shown in FIG. 1 such that a fluid line 16 extends between the pump 11 and the valve 14 for directing fluid to the valve 14, and a fluid line 17 connects from the outlet of the valve 14 and extends back to the supply or tank 10. Also, fluid lines 18 and 19 extend between the two valves 13 and 14, and fluid lines 21 and 22 extend between the motor 12 and the valve 13.
FIG. 1 further shows that the valve 13 is of a control or shiftable type having pairs of passageways 23 which can be connected with the lines 18 and 19 and the lines 21 and 22 for directing fluid to the motor 12 for one direction of rotation of the motor 12. Also, the valve 13 has passageways 24 which can be positioned for flow communication with the lines 19 and 21 and the lines 22 and 18, respectively, for reverse rotation or powering of the unit or motor 12, all as indicated by the showing of the valve 13 and as will be readily understood by anyone skilled in the art. The valve 13 also has restrictors 26 shown thereon, and the valve 13 is shown in a position to flow communicate the valve 14 with the motor 12 to have fluid flow to and from the motor 12 in the respective lines or passageways shown in FIG. 1.
An important feature of the entire system is the valve 14 which is shown in detail in FIGS. 2, 3, and 4. With the inclusion of the valve 14 and the system and by virtue of the arrangement of the valve 14, the fluid can be re-cycled relative to the motor or powered unit 12, and thus in the event that the motor 12 is running at a fast speed beyond that which is actually created by the fluid supplied from the pump 11, such as when the motor 12 is in a tractor transmission which is running downhill, then the fluid can be re-cycled relative to the motor 12 and thus avoid a cavitation condition in the system.
The valve 14 has a body 27 and an interior chamber 28 closed off by a plug 29. Two inlet openings 31 and 32 extend into the body 27 and flow communicate with the chamber 28 through extensions or passageways 33 and 34 and 36 and 37, as shown. Thus, fluid flowing to the inlet openings 31 and 32 will go to the chamber 28 through any or all of the four passageways just described, and those passageways are actually parts of or extensions to the inlet openings 31 and 32.
The valve body 27 also has a fluid outlet opening 38 which flow communicates with the interior chamber 28 and extends to the exterior of the valve body 27 so that fluid can flow from the valve body 27 in a manner hereinafter described. Also, the valve body 27 has a fluid outlet opening 39 which extends in the body 27 through its passageway 41 and flow communicates with the passageways 42 and 43 which are in flow communication with the interior chamber 28, all as shown. Check valves, in the form of balls 44 and 46 are disposed in the outlet passageway described, and compression springs 47 and 48 thereagainst the respective balls 44 and 46 to hold them in the fluid-tight position relative to the passageways 42 and 43, respectively, and thus preclude the escape of fluid through the outlet opening 39 until the fluid reaches the minimum pressure of the check valves 44 and 46, and that pressure might be 60 psi, for one example.
Finally, the valve 14 has a closure in the form of the spool 49 which is movably disposed in the body 27 and has fluid sealing portions 51, 52 and 53 which are in fluid-tight and sliding contact with the cylindrical wall 54 defining the chamber 28. Thus the three sealing portions 51, 52, and 53 respectively block the flow of fluid through the inlet and outlet openings of the valve 14, in a manner hereinafter described. Compression springs 56 and 57 are disposed on opposite ends of the spool 49 and are effective for placing the spool 49 in the center position which is the position shown in FIG. 2. Also, the spool 49 has end walls 58 and 59 which can respectively abut the housing end wall 61 and the end 62 of the plug 29.
Next, describing the operation of the valve 14, FIG. 3 shows the spool 49 shifted to the left, from the FIG. 2 position, and thus the outlet opening 38 is uncovered and therefore fluid can flow through the inlet opening 32 and to the outlet opening 38. The opening 38 is identified in FIG. 1, and thus the flow will go from the valve 14 and through the line 19 to the valve 13 and then to the motor 12 for driving the motor, as desired.
To accomplish the self-responsive or automatic position of the valve 14, as seen in FIG. 3, it will be understood that the pump 11 connects through the line 16 to the inlet 32 and thus pump pressure is presented to the valve chamber 28 in the passageway 34 and also the passageway 37. The fluid pressure presented through the passageway 37 is effective on the right-hand end of the spool 49, as viewed in FIG. 3, such as on the end face or surface 63, and that causes the spool 49 to shift from the FIG. 2 position to the FIG. 3 position and thus open the outlet 38 as shown in FIG. 3. Further, in the FIG. 3 position, the spool sealing portion 53 closes the passageway 43 so fluid cannot escape through the passageway 43 and thus the pressure from the pump 11 is applied to the motor 12.
It will be further noticed that the motor 12 is connected to the inlet 31 through the connecting line 21 and the valve 13 and the connecting line 18, and thus return flow from the motor 12 is presented to the inlet opening 31 in the FIG. 3 position. That return flow is presented to the passageway 42, as can be seen in FIG. 3, and when the pressure reaches the 60 psi selected, then the valve 44 will open and allow that flow to continue to the outlet opening 39 which is connected to the return tank 10 through the line 17.
With the aforementioned arrangement and functioning, the pump 11 will be driving the motor 12, as desired.
If, under a condition where the motor 12 is rotating to demand more fluid than that supplied by the pump 11, such as when the motor 12 is in a vehicle transmission which is now running under its own power in a downhill type of operation, then the pump 27 controls the fluid system and avoids the anti-cavitation by the automatic and self-responsive action of the spool 49 which will then shift to the position shown in FIG. 4. In this condition of the overrun by the motor 12, the fluid pressure in the cavity A on the right-hand side of the spool 49 and as supplied through the passageway 37 will diminish and the fluid pressure will continue and even increase in the passageway 36 and thus present itself to the chamber B to the left of the spool 49. That is, the pressure in chamber B will be greater than the dissipated pressure in chamber A, all due to the aforementioned running of the motor 12 by external means, and thus the spool 49 will shift to the right, as shown in FIG. 4. That will cause the spool sealing portion 51 to block the flow to the outlet passageway 42 and to open the flow to the outlet passageway 43 and also leave the flow to the outlet opening 38. To accomplish the shifting of the spool 49 to the right, as mentioned, the fluid pressure was presented to the spool surface 64 and that of course was an unbalanced pressure which caused the spool 49 to shift as mentioned. Therefore, the output from the pump 11 is directed to the chamber 28 and to the then exposed outlet passageway 43 and the outlet opening 39 and thus to the tank 10. Simultaneously, the fluid from the motor 12 is directed into the inlet opening 31 and to the valve outlet opening 38 and thus back to the motor 12 and this therefore regulates the flow to the motor 12 and thus avoids the cavitation and controls the travel speed, in the instance of using the motor 12 in a vehicle transmission, as mentioned above. Again, the outlet pressure for the valve 46 may be 60 psi, and therefore the pump pressure will be directed through the check valve 46 when it exceeds the specified amount.
In this arrangement, the valve 14 is provided with a fluid closure which is free to move in the chamber 28 according to fluid pressure presented to the chamber 28, as described, and thus the valve 14 is self-responsive. Also, the valves 44 and 46 are pressure released valves which are in respective fluid-flow communication with the two inlet openings 31 and 32, and they are also in fluid-flow communication with the one valve outlet opening 39. Further, the spacing between the passageways 42 and 43, and also relative to the outlet opening 38, is related to the spacing between the valve closure portions 51 and 52 and 53, such that the outlet 38 and the passageway 43 are closed by the closure portions 52 and 53 in FIG. 2; and the outlet 38 is opened when the passageway 43 is closed, respectively by the closure portions 52 and 53, in FIG. 3, and the passageway 42 is open in FIG. 3; and the outlet 38 and the passageway 43 are opened by the closure portions 52 and 53, in FIG. 4, while the passageway 42 is closed by the closure portion 51 in FIG. 4. Thus, the relative spacing between the closure portions and the outlets and passageways is as shown and described herein for the purposes mentioned. | A self-responsive fluid means for anti-cavitation, such as when a fluid motor is rotating in a manner beyond that induced by the fluid pressure fed thereto, and thus the motor itself acts in the nature of a pump to produce a cavitation effect. Thus, there is a fluid motor, a valve controlling flow thereto, a pump, and an additional valve which directs the exhaust from the fluid motor and back to the motor itself, under certain conditions of operation, all to avoid the cavitation effect. The latter valve includes two fluid inlet openings and a movable closure which controls fluid flow to a fluid outlet opening; and pressure relief valve are incorporated in that valve and thus permit and control flow to the reservoir when pressure is at a certain magnitude. | 5 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a tapered roller bearing, and more particularly, to a tapered roller bearing suitably incorporated into the gear device of an automobile transmission.
2. Description of the Related Art
Automobile transmissions are broadly classified into a manual type and an automatic type. Furthermore, they can also be classified according to the driving system of a vehicle into a trans-axle for front wheel drive (FWD), a transmission for rear wheel drive (RWD), and a transfer for four-wheel drive (4WD). These are used to speed-change the drive power delivered from the engine and to transmit it to the drive shaft or the like.
FIG. 7 shows a configuration example of an automobile transmission. This transmission is a synchronous meshing type, in which the left side in the figure is the engine side and the right side is the drive wheel side. A tapered roller bearing 43 is disposed between a main shaft 41 and a main drive gear 42 . In this example, the outer ring raceway surface of the tapered roller bearing 43 is directly formed on the inner circumference of the main drive gear 42 . The main drive gear 42 is supported using a tapered roller bearing 44 so as to be rotatable with respect to a casing 45 . A clutch gear 46 is engaged with and connected to the main drive gear 42 , and a synchro-mechanism 47 is disposed adjacent the clutch gear 46 .
The synchro-mechanism 47 comprises a sleeve 48 that is moved axially (in the left-right direction in the figure) by the action of a selector (not shown), a synchronizer key 49 installed in the inner circumference of the sleeve 48 so as to be movable in the axial direction, a hub 50 engaged with and connected to the outer circumference of the main shaft 41 , a synchronizer ring 51 slidably mounted on the outer circumference (the cone section) of the clutch gear 46 , and a urging pin 52 and a spring 53 for elastically pressing the synchronizer key 49 against the inner circumference of the sleeve 48 .
In the state shown in the figure, the sleeve 48 and the synchronizer key 49 are held at the neutral position using the urging pin 52 . At this time, the main drive gear 42 rotates idle with respect to the main shaft 41 . On the other hand, when the sleeve 48 is moved, for example, to the left in the axial direction, from the state shown in the figure by the operation of the selector, the synchronizer key 49 is moved to the left in the axial direction, following the sleeve 48 , whereby the synchronizer ring 51 is pressed against the inclined surface of the cone section of the clutch gear 46 . This decreases the rotation speed of the clutch gear 46 and increases the rotation speed of the synchro-mechanism 47 . Furthermore, at the time when the rotation speeds of the two have become synchronized, the sleeve 48 is further moved to the left in the axial direction, meshing with the clutch gear 46 . Hence, the main shaft 41 and the main drive gear 42 are connected to each other via the synchro-mechanism 47 . As a result, the main shaft 41 and the main drive gear 42 are rotated synchronously.
In recent years, low-viscosity oil tends to be used for automobile transmissions to meet the needs for automatic transmission (AT), continuously variable transmission (CVT), low fuel consumption, etc. In an environment where low-viscosity oil is used, surface-originated flaking, which causes a very short life, sometimes occurs in the inner ring raceway surface having high surface pressure due to improper lubrication when such adverse conditions as (1) high oil temperature, (2) low amount of oil and (3) loss of pressurization occur simultaneously.
A direct and effective solution to the problem of the short life due to the surface-originated flaking is to reduce the maximum surface pressure. For the purpose of reducing the maximum surface pressure, it is necessary to change the bearing size or to increase the number of the rollers or the bearing if the bearing size is not to be changed. For the purpose or increasing the number of the rollers without decreasing the roller diameter, it is necessary to narrow the distance between the pockets in the cage. However, for this purpose, the pitch circle of the cage must be increased so that the cage is shifted so as to be as close as possible to the outer ring.
As an example in which the cage is shifted so as to make contact with the inner diameter surface of the outer ring, there is a tapered roller bearing shown in FIG. 8 (refer to Japanese Patent Laid-Open No. 2003-28165). In this tapered roller bearing 61 , the outer circumferential surface of the small diameter annular section 62 a and the outer circumferential surface of the large diameter annular section 62 b of the cage 62 are disposed in slide contact with the inner diameter surface of the outer ring 63 so as to guide the cage 62 . Furthermore, a recess 64 for suppressing drag torque is formed on the outer diameter surface of the pole section 62 c of the cage 62 , thereby maintaining the non-contact state between the outer diameter surface of the pole section 62 c and the raceway surface 63 a of the outer ring 63 . The cage 62 has the small diameter annular section 62 a , the large diameter annular section 62 b , and the multiple pole sections 62 c that connect the small diameter annular section 62 a to the large diameter annular section 62 b in the axial direction and are formed with the recess 64 on the outer diameter surface thereof. Furthermore, multiple pockets, in each so which a tapered roller 65 is rollably accommodated, are provided so that each pocket is disposed between two pole sections 62 c . The small diameter annular section 62 a is provided with a flange section 62 d integrally extending to the inner diameter side. The tapered roller bearing shown in FIG. 8 is an example intended to improve the strength of the cage 62 , wherein the cage 62 is shifted so as to make contact with the inner diameter surface of the outer ring 63 in order to increase the circumferential width of the pole section 62 c of the cage 62 .
In the tapered roller bearing 61 described in Japanese Patent Laid-Open No. 2003-28165, the cage 62 is shifted to the outer diameter side so as to make contact with the inner diameter surface of the outer ring 63 in order to increase the circumferential width of the pole section 62 c of the cage 62 . Furthermore, because the recess 64 is provided in the pole section 62 c of the cage 62 , the plate thickness of the pole section 62 c becomes inevitably thin, and the rigidity of the cage 62 is reduced. Hence, the cage 62 may be deformed due to stress during the assembly of the bearing 61 or may also be deformed during the rotation of the bearing 61 .
On the other hand, a conventional typical tapered roller bearing with a cage, other than the tapered roller bearing described in Japanese Patent Laid-Open No. 2003-28165, is designed so that the roller coefficient γ (roller filling factor) defined by the following formula is usually 0.94 or less in order to securely obtain the pole width of the cage 72 and obtain appropriate strength of the pole of the cage 72 and smooth rotation while avoiding contact between the outer ring 71 and the cage 72 as shown in FIG. 9 .
Roller coefficient γ=( Z·DA )/(π· PCD )
where Z is the number of the rollers, DA is the average diameter of the rollers, and PCD is the pitch circle diameter of the cage.
In addition, in FIG. 9 , numeral 73 denotes the tapered roller, numeral 74 denotes the surface of the pole, numeral 75 denotes the inner ring, and e denotes a window angle.
SUMMARY OF THE INVENTION
The present invention is intended to increase the load capacity of a tapered roller bearing and to prevent premature breakage due to excessive pressure on the raceway surfaces thereof.
The tapered roller bearing according to the first aspect of the invention comprises an inner ring, an outer ring, multiple tapered rollers rollably disposed between the inner and outer rings, and a cage for holding the tapered rollers at predetermined circumferential intervals, wherein the roller coefficient γ thereof is larger than 0.94.
The second aspect of the invention is characterized in that the window angle of the pocket of the tapered roller bearing according to the first aspect of the invention is in the range of 55° to 80°. The window angle is the angle formed by the guide surfaces of the pole sections making contact with the circumferential surface of each roller. The reason for setting the minimum value of the window angle at 55° is to secure a proper state of contact with the roller. In addition, the reason for setting the maximum value at 80° is that if the angle is larger than this value, the radial pressing force increases, causing a danger that smooth rotation cannot be obtained even if the cage is made of a self-lubricating resin material. In the case of ordinary cages, the window angle thereof is in the range of 25° to 50°.
The third aspect of the invention is characterized in that the cage of the tapered roller bearing according to the first or second aspect of the invention is formed of an engineering plastic superior in mechanical strength, oil resistance, and heat resistance. In comparison with a cage formed of a steel plate, the cage formed of a resin material is light-weight, self-lubricating, and low in friction coefficient. These features, together with the effect of the lubricating oil present in the bearing, make it possible to suppress occurrence of abrasion due to contact with the outer ring.
In comparison with a steel plate, such a resin is light in weight and low in friction coefficient, thereby being suitable for reducing torque loss and cage abrasion at the time of starting the rotation of the bearing.
Engineering plastics include general-purpose engineering plastics and super engineering plastics. Typical ones are given below. However, they are examples of engineering plastics, and engineering plastics are not limited to those described below.
[General-purpose engineering plastics] polycarbonate (PC), polyamide 6 (PA6), polyamide 66 (PA66), polyacetal (POM), modified polyphenylene ether (m-PPE), polybutylene terephthalate (PBT), GF-reinforced polyethylene terephthalate (GF-PET), ultra-high molecular weight polyethylene (UHMW-PE)
[Super engineering plastics] polysulfone (PSF), polyethersulfone (PES), polyphenylene sulfide (PPS), polyarylate (PAR), polyamideimide (PAI), polyetherimide (PEI), (polyetheretherketone (PEEK), liquid crystal polymer (LCP), thermoplastic polyimide (TPI), polybenzimidazole (PBI), polymethylpentene (TPX), poly 1,4-cyclohexane dimethylene terephthalate (PCT), polyamide 46 (PA46), polyamide 6T (PA6T), polyamide 9T (PA9T), polyamide 11, 12 (PA11, 12), fluororesin, polyphthalamide (PPA)
Because the roller coefficient γ of the tapered roller bearing is set so as to be greater than 0.94, not only the load capacity increases but also the maximum surface pressure on the raceway surfaces can be reduced. Therefore, it is possible to prevent surface-originated flaking, which causes a very short life, under severe lubrication conditions.
BRIEF DESCRIPTION OF THE DRAWINGS
The above and other objects and advantages of the invention will be more apparent from the following description and drawings, in which:
FIG. 1A is a cross-sectional view showing a tapered roller bearing according to the present invention, and FIG. 1B is a vertical-sectional view showing the bearing;
FIG. 2 is a partially enlarged sectional view showing the tapered roller bearing having a minimum window angle;
FIG. 3 is a partially enlarged sectional view showing the tapered roller bearing having a maximum window angle;
FIG. 4 is table showing the results of bearing life tests.
FIG. 5 is a partially sectional view showing a tapered roller bearing according to a modified embodiment of the present invention;
FIG. 6 is a sectional view showing a pole section or the cage shown in FIG. 5 ;
FIG. 7 is a sectional view showing a general automobile transmission;
FIG. 8 is a sectional view showing a conventional tapered roller bearing with the cage shifted to the outer ring; and
FIG. 9 is a partially enlarged sectional view showing another conventional tapered roller bearing.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
An embodiment according to the present invention will be described hereinafter referring to FIGS. 1 to 4 . A tapered roller bearing 1 according to the embodiment, shown in FIGS. 1A and 1B , has a tapered raceway surface 2 a , and comprises an inner ring 2 having a small flange section 2 b on the small diameter side and a large flange section 2 c on the large diameter side of the raceway surface 2 a , an outer ring 3 having a tapered raceway surface 3 a , multiple tapered rollers 4 rollably disposed between the raceway surface 2 a of the inner ring 2 and the raceway surface 3 a of the outer ring 3 , and a cage 5 for holding the tapered rollers 4 equal circumferential intervals. The roller coefficient γ of the taper-roller bearing 1 is herein greater than 0.94.
The cage 5 , integrally molded of a super engineering plastic, such as PPS, PEEK, PA, PPA or PAI, comprises a small diameter side annular section 5 a , a large diameter side annular section 5 b , and multiple pole sections 5 c that make axial connection between the small diameter side annular section 5 a and the large diameter side annular section 5 b.
The minimum window angle θmin of the window angle θ of pole surfaces 5 d is 55° as shown in FIG. 2 , and the maximum window angle θmax thereof is 80° as shown in FIG. 3 . The window angle in the typical tapered roller bearing with a cage that is spaced from the outer ring as shown in FIG. 9 is approximately 50° at most. The reason for setting the minimum window angle θmin at 55° is to secure a proper state of contact with the roller. If the window angle is less than 55°, the state of contact with the roller becomes improper. That is, in the case that the window angle is 55° or more, γ can be made greater than 0.94, and a proper state of contact can be ensured while the strength of the cage is ensured. Furthermore, the reason for setting the maximum window angle θmax at 80° is that if it is larger than this value, the pressing force in the radial direction increases, and there is a danger that smooth rotation cannot be obtained even if the cage is made of a self-lubricating resin material.
FIG. 4 shows the results of bearing life tests. In FIG. 4 “Comparative example 1” in the “Bearing” column is a typical conventional tapered roller bearing with a cage that is spaced from the outer ring. “Embodiment 1” is a tapered roller bearing according to the present invention, the roller coefficient γ of which is greater than 0.94, being different from the conventional bearing only in this respect. “Embodiment 2” is another tapered roller bearing according to the present invention, the roller coefficient γ of which is greater than 0.94, and the window angle of which is set in the range of 55° to 80°. The tests were conducted under severe lubrication and excessive load conditions. As clarified in the figure, the life of “Embodiment 1” is more than twice the life of “Comparative example 1.” Furthermore, the life of “Embodiment 2” is approximately five or more times the life of “Embodiment 1” although the roller coefficient thereof is the same (0.96) as that of “Embodiment 1.” “Comparative example 1”, “Embodiment 1” and “Embodiment 2” measure 45 (inner diameter)×81 (outer diameter)×16 overall width (unit: mm), the number of the rollers in “Comparative example 1” is 24, the number of the rollers in “Embodiment 1” and “Embodiment 2” is 27, and oil film parameter Λ is 0.2.
Next, a modified embodiment according to the present invention will be described referring to FIGS. 5 and 6 . In the tapered roller bearing 1 shown in the figures, protruding sections 5 f having a convex shape protruding to the outer ring raceway surface are formed on the outer diameter surfaces of the pole sections 5 c of the cage 5 that is integrally molded of an engineering plastic. In other respects, the cage 5 is the same as that described above. The contour of the protruding section 5 f , in the cross-sectional direction of the pole section 5 c , is arc-shaped as shown in FIG. 6 . The curvature radius R 2 of this arc shape is made smaller than the radius R 1 of the outer ring raceway surface. The shape is determined so that a proper wedge-shaped oil film is formed between the protruding section 5 f and the outer ring raceway surface, and it is desirable that the curvature radius R 2 of the protruding section should be approximately 70 to 90% of the radius R 1 of the outer ring raceway surface. If the curvature radius is less than 70%, the inlet opening angle of the wedge-shaped oil film becomes so large that the dynamic pressure decreases. Furthermore, if it is more than 90%, the inlet angle of the wedge-shaped oil film becomes so small that the dynamic pressure also decreases. In addition, the width W 2 of the protruding section 5 f is desirably 50% or more of the width W 1 or the pole section 5 c (W 2 ≧0.5×W 1 ). The reason is that if the width is less than 50%, the height of the protruding section 5 f for forming a proper wedge-shaped oil film cannot be secured sufficiently. In addition, because the radius R 1 of the outer ring raceway surface continuously changes from the large diameter side to the small diameter side, the curvature radius R 2 of the protruding section 5 f is also changed continuously from the large curvature radius R 2 of the large diameter side annular section 5 b to the small curvature radius R 2 of the small diameter side annular section 5 a accordingly in a similar way.
Because the tapered roller bearing 1 shown in FIGS. 5 and 6 is configured as described above, when the bearing 1 rotates and the cage 5 starts to rotate, a wedge-shaped oil film is formed between the outer ring raceway surface and the protruding section 5 f of the cage 5 . This wedge-shaped oil film produces dynamic pressure substantially proportional to the rotation speed of the bearing 1 . Therefore, even if the pitch circle diameter (PCD) of the cage 5 is made larger than the conventional value so as to dispose the cage close to the outer ring raceway surface, the bearing 1 can be rotated without causing much abrasion or torque loss. Hence, the number of the rollers can be increased without trouble.
Although the embodiments according to the present invention have been described above, the present invention is not limited to the above-mentioned embodiments but can be modified variously. For example, although a super engineering plastic, such as PPS, PEEK, PA, PPA or PAI, is used as the material of the cage in the above-mentioned embodiments, it may be possible that glass fiber, carbon fiber or the like is mixed with such a resin material or other engineering plastics as necessary to increase the strength.
INDUSTRIAL APPLICABILITY
The tapered roller bearing 1 according to the present invention can be incorporated into automobile transmissions, and can also be used for automobile differential gears and automobile gear devices, and for other applications. | A tapered roller bearing has an increased load capacity and has a decreased maximum face pressure on the raceway surfaces without lowering the rigidity of the cage. The tapered roller bearing includes an inner ring, an outer ring, multiple tapered rollers rollably disposed between the inner ring 2 and the outer ring 3 , and a cage for holding the tapered rollers at predetermined circumferential intervals, wherein the roller coefficient γ thereof is larger than 0.94. Herein, γ=(the number of the rollers×the average diameter of the rollers)/(π×PCD). | 5 |
Background of the Invention
1. Field of the Invention
This invention relates to the field of underwater breathing apparatus (UBA), more specifically to self-contained, closed-circuit underwater breathing apparatus, which operates without need of air or breathing gas from an outside supply remote from the diver, and wherein carbon dioxide gas (CO 2 ) generated by a diver is constantly removed and oxygen (O 2 ) needed for metabolism is constantly supplied.
2. Description of the Prior Art
A closed-circuit UBA is a form of self-contained underwater breathing apparatus (SCUBA) in which a diver's breathing gas is recycled through a closed loop, adding oxygen and removing carbon dioxide gases as needed. The carbon dioxide gas is typically removed by chemical absorption. UBA typically comprise an oxygen supply bottle, a canister containing CO 2 absorbent, a breathing bag or flexible volume element, connecting hoses, a mouthpiece for the diver, and a diluent gas or inert gas bottle. Inert gases such as helium or helium/nitrogen mixtures are often used. Some UBA versions monitor O 2 electronically and add oxygen when inspired O 2 concentrations drop below desired levels. The only mechanical adjustments that can be made by a diver involve the degree of filling of the breathing bags. As ambient pressure changes, for example as the diver goes deeper or rises, the volume of gas within the breathing bag(s) contracts or expands respectively, and diluent gas may be added or dumped, either manually or automatically. Some UBA have a single breathing bag; others have one for the inhalation side and another for the exhalation side of the recirculating loop.
The closed-circuit breathing apparatus and its basic construction and principles of operation have been known for some time (U.S. Pat. No. 3,837,337 to LaViolette, 1974). Improvements to such equipment are always being made for the diving community, which includes military, commercial underwater construction and salvage, and sport divers. For example, improvements in the control of air or breathing gas flow within the apparatus are discussed in U.S. Pat. No. 4,440,166 to Winkler, et al, (1984), particularly with respect to emergency mechanical control system in the event that the electronics fails.
The large majority of patents in the art center around the two critical performance factors for UBA, namely CO 2 absorption and O 2 control. Almost none deal with improving or lessening the difficulty of breathing at depth, particularly during arduous exercise or heavy work. Those that do, deal only with the fluid mechanical flow resistance and not other sources of impedance or mechanical resistance to breathing arising from the elements in the UBA including tubing or hoses, canister, etc. In general, breathing resistance in a UBA can be significant for the diver; it can reduce his effectiveness or the duration of work capability, and may, more seriously, contribute to loss of consciousness.
The mechanical resistance to breathing on a UBA is complex, because the breathing is sinusoidal or periodic in nature and not a steady flow. In this kind of flow situation dynamic analyses must be employed, such as those common to the art and discussed in detail by R. Peslin and J. J. Fredberg, "Oscillation Mechanics of the Respiratory System", chap. 11 in Handbook of Physiology: Vol. III, The Respiratory System, A. P. Fishman (ed.), 1987, American Physiol. Soc., Bethesda, Md., and H. D. Van Liew, "The Electrical-Respiratory Analogy When Gas Density is High", Undersea Biomedical Research, vol. 14, no. 2, (1987) pp. 149-160.
In a periodic flow, allowance must be made for additional resistances to the motion of the breathing gas. These resistances are termed elastic and inertial, and they cause increased energy loss, because the diver must overcome them, as well as the resistance due to flow, to keep breathing. Inertial resistance or inertance arises from accelerations and decelerations in the gas flow or displaced water due to the periodic nature of the flow. Elastic resistance or elastance arises from pressure changes due to flow entering a closed volume or pressure changes due to volume changes (in submersed breathing bags for example). Because of the oscillatory or periodic nature of the flow, complex algebra must be used to describe the overall resistance to flow, which is termed the impedance. Therefore;
Z=R-(jE/ω)+jωI Eqn. 1
where Z is the impedance in units of pressure/flow rate, R is the resistance due purely to flow (the flow resistance) in the same units, E is the elastance in units of pressure/volume, I is the inertance in units of pressure/flow acceleration, and ω is the radian frequency in units of reciprocal time. Eqn. 1 applies to a series arrangement of R, E and I typical of UBA. Impedance is composed of a real part, namely the flow resistance, and an imaginary part, which is a combination of the inertance and the elastance. The magnitude of Z can be computed by;
|Z|=√[R.sup.2 +(ωI-E/ω).sup.2 ]Eqn. 2
so that all three components of impedance contribute to the pressure required to drive the flow in the system.
At the natural or resonant frequency, the inertial and elastic terms in Eqn. 2 cancel, leaving only the flow resistance contributing to the impedance. Thus impedance is at a minimal value when the system is oscillating at the natural frequency, the condition of which is given below;
ω.sub.n =√(E/I) Eqn. 3
The foregoing are terms of the art necessary to understand the present invention, but they do not constitute the invention.
Impedance in the UBA adds to the positive and negative respiratory pressures that a diver must generate to breathe. Impedance is generated by the elastance, inertance and resistance in the UBA. Resistance in UBA arises from breathing hoses, valves, changes in flow diameter, the canister and other similar obstructions in the flow path. Resistance is the fluid mechanical cost of moving a volume of fluid at a given rate. The ratio of pressure difference required to cause a given flow rate to the flow rate is termed the flow resistance.
Elastance is the reciprocal of compliance in the system and is derived in UBA primarily from changes in volume of the breathing bag when immersed. If these changes in volume lead to a vertical expansion or contraction of the bag, pressure is altered by hydrostatic forces, wherein the pressure change (ΔP) is given by;
ΔP=ρgΔh Eqn. 4
where Δh is the vertical displacement and ρ is the density of ambient fluid, usually water or sea water, and g is the acceleration of gravity. The shape of the bag and its orientation in the water have an effect of the elastance. Reference is made to D. D. Joye, J. R. Clarke, N. A. Carlson and E. T. Flynn, "Formulation of Elastic Loading Parameters for Studies of Closed-Circuit Underwater Breathing Systems", NMRI Technical Report 89-89, Bethesda, Maryland (also available from NTIS). Elastance is inversely proportional to the cross-sectional area that is perpendicular to the vertical direction. In general, as the breathing bag changes volume, the hydrostatic component of pressure from the top to the bottom of the bag is the elastic pressure. There are other contributions to elastance in a UBA, for example the volume of internal hoses and containers in the breathing loop, that have an additional, but much smaller, effect.
Inertance arises from the acceleration of mass in a system. The larger the mass the higher the inertance. Accelerated masses comprise breathing gases, water displaced by the breathing bag and various UBA components. Inertance (I) is calculated from the formula:
I=m/A.sup.2 Eqn. 5
where m is mass and A is the cross-sectional area through which mass is moved, or the sectional area which moves with the mass.
The force that moves the flow of breathing gas is respiratory pressure. Although the respiratory pressure imposed by UBA elastance can be relatively high at the low frequencies commonly encountered in a diver's breathing pattern, which is typically in the range 5-60 breaths/minute, particularly 10-40 bpm, there have been no efforts to either statically or dynamically reduce UBA elastic impedance to make it easier for the diver to breathe.
Some efforts have been made in the design of breathing machines (not UBA) that simulate human breathing or can be adjusted to generate other breathing conditions, and/or to provide adjustable impedance. Reference is made to M. Younes, D. Bilan, D. Jung and H. Kroker, "An apparatus for altering the mechanical load of the respiratory system", J. Applied Physiology, vol. 62, no. 6 (1987) pp. 2491-2499, wherein adjustment to elastance by changing gas volume in the machine is shown. Inertance is not adjusted, and oscillatory behavior is damped, not fostered.
SUMMARY OF THE INVENTION
Accordingly, an object of this invention is to reduce the impedance in a UBA by changing the inertance so that elastic and inertial contribution to impedance cancel.
A further object of this invention is to provide a means for continual adjustment of the inertance in a UBA to change the natural frequency of the UBA, so that the resonant frequency of the UBA is equal to the diver's breathing frequency, thereby minimizing impedance to breathing.
These and additional objects of the invention are accomplished by tuning a UBA, by which is meant adjusting inertance so that the natural frequency of the UBA is modified to equal the breathing frequency of a diver using the UBA. Inertance is altered in a controlled manner by adjusting mass associated with motion of the breathing bag, particularly the mass of water moved by displacement of the breathing bag The invention comprises (a) a means for sensing the physical variables of a diver's breathing, particularly the diver's breathing frequency, (b) a means for determining elastance of the UBA, (c) a means for computing the resonant frequency of the UBA, and (d) means for changing the inertance of the UBA so that the resonant frequency of the UBA always equals the diver's breathing frequency.
BRIEF DESCRIPTION OF THE DRAWINGS
A more complete appreciation of the invention will be readily obtained by reference to the following Description of the Preferred Embodiments and the accompanying drawings The representation in the figure is diagrammatic and no attempt is made to indicate actual scales or precise ratios.
FIG. 1 is a schematic view of a preferred embodiment of the present invention (adjustable length hose) in cooperation with the other elements of the invention incorporated into an otherwise typical recirculating underwater breathing apparatus.
FIG. 2 is a schematic view of another preferred embodiment of the present invention with a fixed-length hose with parallel path, adjustable valve.
FIG. 1(a) is a schematic showing the telescopic tube embodiment in place of the bellows-type extendable tube embodiment of FIG. 1.
FIG. 2(a) is a schematic showing the moving mass embodiment in place of the inertance tube embodiment of FIG. 2.
FIG. 3 is a schematic in plan view showing the rotating disc embodiment in place of the endless cable element of the mechanical actuator embodiment illustrated in FIG. 2.
FIG. 3(a) is a side view of the embodiment illustrated in FIG. 3.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The means for sensing a diver's breathing frequency comprises a pressure transducer, built into the UBA respiratory circuit and a microprocessor, which computes respiratory frequency from the periodicity of a pressure waveform characteristic of the diver's breathing pattern. The pressure transducer may be of any type current in the diving art, such as the metal diaphragm differential pressure cells manufactured by Validyne Engineering Corporation, Northridge, Calif., or a miniaturized piezoelectric device adapted for use underwater, or pressure transducers whose working principles can be adapted for underwater use. These transducers sense differential pressure by deflection of a diaphragm or stretching of a thin film of material changing the resistance or electrical properties of the material, which can be sensed as a voltage or current change. The microprocessor can be any adaptation of similar units commonly used in automobiles today to monitor engine function and effect changes in the operating variables. The appropriate circuit design simply needs to be carried out and the unit programmed to obtain the desired functional performance. This is well within the skill of the present electronic art. Frequency can be sensed from pressure waveform by counting peaks (from the diver's mouth pressure) and measuring the time elapsed between peaks.
The means for determining elastance of the UBA comprises look-up tables, programmed tables, and the like. Here again the microprocessor can be used with a different program to compute the elastance, for example by methods described in the Joye, et al reference cited previously. Elastance, to a first approximation, is equal to the inverse of the horizontal cross-sectional area of the breathing bag or counterlung. Since no counterlung is spherical in shape, and since a diver will assume any orientation in the water, elastance depends on the shape of the bag and the orientation. A table of elastance as a function of orientation can be prepared by simple experiments on an actual UBA in the water in vertical, horizontal and rotational positions, and the computer can interpolate between these values as appropriate. These values can be provided by the manufacturer or determined by standard techniques without undue effort.
Since elastance will depend on orientation of the breathing bag in the water for most geometrical design possibilities, a 3-axis position indicator, located within the UBA will be necessary to accurately compute elastance. Position indicators are more common to the aerospace art, particularly airplanes with pitch (up and down at the head), yaw (side-to-side) and roll axes and displays common in the cockpit. A position indicator adapted for use underwater is described here as an example: Three pressure transducers are placed in a horizontal plane on the breathing bag housing, and pitch, roll and yaw are determined by the different readings on these transducers. For example, the north transducer reads pressure A, the west transducer reads pressure B, and the east transducer reads pressure C. If A=B=C, the diver is horizontal (pressure is relative to a common point on the UBA, preferably in the center. If B>C and both greater than A, then the diver is pitched down at the head and rolling to the right. The degree to which this is true depends on the magnitude of the pressure signals. Many other combinations could be discussed, but the principle is clear.
The means for computing the resonant frequency of the UBA comprises a microprocessor which computes the adjustment in the inertance of the UBA breathing bags needed to minimize impedance, for example through Eqn (3). The means for changing inertance comprises any means selected from the following: (a) changing the mass of water displaced by motion of the breathing bag by altering the geometry of an exit hose, for example changing the length of this hose through telescoping means, attached to the breathing bag housing, an otherwise closed structure placed over the breathing bag for protection, (b) changing the moment of inertia of the breathing bags, for example adding or removing mass attached thereto, (c) changing the geometry of the breathing bag housing or hose by having holes placed in either, and having a means to open or close those holes to change the primary direction of flow of the water displaced by motion of the breathing bags, for example axial to radial, and (d) using a valve and a fixed length of hose, wherein the valve bleeds off water in the hose by adding a parallel escape path for water to be diverted away from moving through the fixed length of hose.
The reactive UBA of the present invention requires that inertance be known for the above mentioned methods as a function of geometric variable, for example the length of an adjustable-length tube. The microprocessor computes the required inertance from Eqn (3), then the corresponding length of tube that gives that inertance. The microprocessor then compares the length required to that existing and this signal is sent to a mechanical means for adjusting the length of the tube, for example. The mechanical system may comprise any kind of linkage that can change the tube length.
Old UBA were designed to minimize only resistive impedance; they did not react to the diver, other than to maintain minimal inspired partial pressure of oxygen. In addition to performing all the functions of existing UBA, the new "Reactive UBA" will continually minimize UBA impedance by tuning the UBA to resonate at the diver's respiratory frequency.
Having described the invention, the following examples are given to illustrate specific applications of the invention including the best mode now known to perform the invention. There may be other ways to do the basic tasks of the present invention, once the invention is known, thus these specific examples are not intended to limit the scope of the invention described in this application.
With reference to FIG. 1, basic elements of the UBA and features of the present invention are shown. The diver breathes on mouthpiece [1]. Breathing gas circulates through hose [2]; arrows show direction of gas flow. The CO 2 from the diver's exhale gas is absorbed in canister [3], make-up oxygen is added by oxygen bottle [4] as needed. The breathing bag [5] provides a capacitance in the system. The UBA housing [6] is generally porous to water, so all the elements are in a water environment. Diluent gas bottle [7] for adjusting volume in the breathing bag is also shown.
With respect to the elements of the present invention, pressure is sensed by pressure transducer [8] which sends a signal to microprocessor [9], which then determines the breathing frequency of the diver from the pressure pulse waveform. Microprocessor [9] also receives a signal from the 3-axis orientation transducer [10], computes the elastance from appropriate tables and formulae, then also computes the inertance required to match UBA resonant frequency to the diver's breathing frequency. Microprocessor [9] may need, additionally, position information from an electro-mechanical actuator [11], if the microprocessor is a separate unit from the electro-mechanical actuator, as is shown in FIG. 1. Alternatively microprocessor [9] can be built into the electro-mechanical actuator, so that the position of the actuator can be sensed directly, through gears, for example, or otherwise, rather than remotely. Microprocessor [9] compares the frequency of the diver's breathing to the computed resonant frequency of the UBA and sends an appropriate signal to the electro-mechanical actuator [11] which then adjusts the length of an extendable tube [12], for example a tube with bellows, or a more smooth-walled telescoping tube, through mechanical or magnetic means [13]. In the alternative embodiment, FIG. 1(a) shows telescopic tube [12a] in place of bellows type extendable tube [12] of FIG. 1. This is a simple alternative that operates similar to a slide trombone. All other parts remain the same. Adjusting the length of the tube [12] changes the inertance of the UBA by changing the mass of water that is accelerated by breathing bag displacement. The extendable hose [12] of FIG. 1 moves in a porous housing [14] for retention and protection. The breathing bag is contained in an otherwise sealed compartment [15], so that all water displaced by the changing volume of the breathing bag is forced out hole [16] into hose [12]. Alternatively, for access of water, initially, to compartment [15], the compartment may be fitted with a valve [17].
Mechanical means [13] may comprise an endless, flexible cable fixedly attached at one point to a moveable, outlet end of extendable hose [12]. The other end of extendable hose [12] is fixedly attached to the sealed compartment [15] containing the breathing bag at hole [16]. Alternatively, magnetic means may be used to move the hose; or a worm gear and rack, or other mechanical linkage devices adaptable from the art may be used to change the length of extendable hose [12] by moving the hose outlet.
In order to return hose or shorten its length, a spring-loaded return mechanism is preferred. Other mechanisms are within the skill of the art, as it is well known that it is easier to extend a flexible member than it is to contract or compress it.
The length of extendable hose [12] may need to be longer than the shoulder-to-hip length shown in FIG. 1. In these cases alternative designs for moving the hose in a confined space can be used. For example, a rotating, circular disc, as illustrated in FIG. 3, to which a moveable end of the hose is attached may be used.
FIG. 3 shows the rotating disc [21] embodiment in which the disc [21] is attached to the flexible cable [13]. The cable [13] is moved by the shaft [23] from mechanical actuator [11] which, in turn, is moved by microprocessor [9]. As seen in FIG. 3(a), edge wall [22] on the disc prevents extended tube [12] from slipping, kinking etc. This edge wall [22] ensures extension of the tube along the circumference of the rotating disc [21]. Disc [21] can move in both clockwise and counter-clockwise directions to extend or contract tube [12].
It is preferred to keep the extendable hose as close to the UBA housing as possible, primarily for ease in length adjustment, but the extendable hose in FIG. 1 can be extended around the lower back, for example, if necessary. Design modifications in the linkage will have to be made in that event, but these and others will be modifications within the scope of the art and the present invention.
Another particularly preferred embodiment is shown in FIG. 2. Exit hose [18] is a rigid, non-extendable tube of fixed length, and adjustable bleed valve [19] acts to change the mass of water moving through the tube by creating a parallel path through which water can also flow. As the valve is operated, it can have equal, greater or less resistance than the tube. The valve is placed at one end of a tee and the fixed-length tube is attached to another end of the tee. Valve opening is controlled by microprocessor [9], or alternatively or additionally, by hand. As the valve is opened, a greater mass of water is diverted from moving through the tube and inertance is reduced. As the valve is closed the opposite occurs.
Should the electronics fail, the diver is not endangered in either preferred embodiment. The valve can be made to fail open or fail closed, and in either event water from the volume change of the breathing bag will have an opening through which to escape. Another important constraint on the ability of the UBA to oscillate is to have minimal flow resistance in the path between breathing bag housing and tube exit. A high resistance here will tend to damp out the oscillatory character of the water motion in this apparatus and negate the effect of inertance.
A further alternative in the method of adjusting inertance described above is to substitute a solid, moveable mass, denser than water, for the water in the fixed-length tube. Water displaced by the breathing bag moves this mass, and the valve bleeds off the displaced water as above. The solid mass is attached to the housing or tube by a weak spring, and a rolling seal or other means can be used to prevent leakage of displaced water past the solid, moveable mass. This embodiment is illustrated in FIG. 2(a) which shows that low inertance can be generated by a moving mass [24] instead of the mass of water in the fixed tube [18]. The moving mass [24] can be solid, (e.g. lead, depleted uranium etc.) or liquid, (e.g. mercury in a suitable container). Sealing means [25] prevents water from moving past the moving mass [24]. Spring [26] anchors the mass in an equilibrium position and returns it to same after mass [24] moves. Using a different mass changes the inertance in the tube. We prefer a weak spring here so as not to add additional force required to move the mass [24] which would increase the work of breathing for the diver. A rolling seal is shown in FIG. 2(a), but other sealing means with low friction can also be used. The advantage of this method is that smaller, or more convenient geometries for equivalent inertance can be used.
Obviously, many modifications and variations of the present invention are possible in light of the above teachings. It is therefore to be understood that, within the scope of the appended claims, the invention may be practiced otherwise than as specifically described. | This invention comprises a tunable underwater breathing apparatus (UBA) inhich the resonant frequency of the UBA may be adjusted to meet the diver's breathing frequency by controlling the inertance component of the UBA impedance. The principles of the present invention may be adapted to existing UBA with minor redesign and some additions. | 1 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the invention
[0002] The present invention relates generally to sequential decoding, and more specifically to techniques for sequentially decoding an incoming (received) data sequence in an attempt to find the most likely path in a code tree.
[0003] 2. Description of Related Art
[0004] Prior to turning to the present invention, it is deemed preferable to describe, with reference to FIGS. 1 - 5 , sequential decoding technology known as the Fano algorithm.
[0005] Reference is made to FIG. 1, a simple example of an encoder 10 , which takes the form of a binary convolutional encoder, is illustrated in block diagram form. The encoder 10 is comprised of a shift-register consisting of three flip-flops 12 a - 12 c and two exclusive-or gates 14 a - 14 b, all of which are coupled as shown. In order to initialize the flip-flops 12 a - 12 c, a control signal, which takes a logic level 0 (for example), is applied to the flip-flops 12 a - 12 c by way of an input terminal 16 c. Each of the flop-flops 12 a - 12 c, in response to logic level 0 of the control signal, is cleared to zero. After the initialization of the flip-flops 12 a - 12 c, the control signal continues to assume a logic level 1 . When a plurality of information symbols are successively applied to the flip-flop 12 a via an input terminal 16 b while the control signal takes a logic level 1 , they are shifted one by one to the subsequent flop-flops 12 b and 12 c in synchronism with a clock signal applied to the flip-flops 12 a - 12 c by way of an input terminal 16 a. In the above, each of the information symbols applied to the encoder 10 via the input terminal 16 b is binary, and therefore, to be precise, has to be referred to as an information bit. However, in the instant disclosure, for the sake of convenience of description, the information bit may typically be referred to as information symbol.
[0006] The exclusive-or gate 14 a has four inputs respectively coupled to receive directly the information symbol by way of the input terminal 16 b and the outputs of the flip-flops 12 a - 12 c, and then applies the output thereof to an output terminal 18 b. The other exclusive-or gate 14 b has three inputs for respectively directly receiving the information symbol via the input terminal 16 b and the outputs flip-flops 12 b and 12 c, and applies the output thereof to an output terminal 18 c. On the other hand, the incoming information symbol is directly fed to an output terminal 18 a.
[0007] Assuming that information symbols u 1 , u 2 , u 3 , . . . are sequentially applied to the encoder 10 through the input terminal 16 b. The initial information symbol u 1 determines first three encoded data sequence x 1 (1) , x 1 (2) , x 1 (3) (=x 1 ) which appear at the output terminals 18 a - 18 c. The next three encoded data sequence x 2 (1) ), x 2 (2) ), x 2 (3) (=x 2 ) are functions of the first two information symbols u 1 and u 2 , and the following three encoded symbols x 3 (1) ), x 3 (2) ), x 3 (3) )(=x 3 ) are functions of u 1 , u 2 , u 3 , and so forth. This dependence of the encoded data sequence upon the inputted information symbol sequence imposes a treelike structure on the set of the encoded data sequences, which is illustrated in FIG. 2.
[0008] Referring to FIG. 2, the leftmost node of code tree, indicated by a black circle, is called an origin node, while the rightmost nodes of the code tree are respectively called terminal nodes. The leftmost symbol triplets 111 and 000 along the upper and lower branches stemming from the origin node, correspond to the responses of the encoder 10 to the initial information symbol (viz., u 1 ) 1 or 0 . Branching off to the right from the response 111 to an initial 1 are the responses to a 1 or 0 following an initial 1 , and so forth. By way of example, the response of the encoder 10 to the information sequence u 1 = 1 , u 2 = 1 , u 3 = 0 , u 4 = 0 is highlighted in the tree code of FIG. 2.
[0009] As mentioned above, the encoder 10 forms a path through the code tree corresponding to an incoming information symbol sequence to be encoded. It follows that sequential decoding can be regarded as the process of determining the path in the code tree which was followed by the encoder. That is to say, a sequential decoder reconstructs the encoder's path through the tree on the basis of the received data sequence.
[0010] [0010]FIG. 3 is a diagram showing a code tree for use in sequentially decoding a received data sequence. Although the code tree of FIG. 3 is exactly identical to that shown in FIG. 2 (viz., replica of code tree of FIG. 2), it is reiterated for the sake of convenience of description.
[0011] Assuming that the encoder 10 of FIG. 1 outputs a data sequence 111 101 001 000 which is transmitted to a receiver via a binary symmetrical communication channel, and the received data sequence is 101 101 001 000 due to deterioration during the transmission over a noisy channel. In this case, the second bit of the first block is erroneously received.
[0012] As mentioned above, the first three symbols (bits) of the received data sequence should be either 111 or 000 , and in this particular case, it is hypothesized that the first three symbols transmitted are 111 in that the Hamming distance is shorter than the other triplet 000 . If this assumption is correct, it is hypothesized that the next three symbols are 101 , and in a similar manner, it is further hypothesized that the following symbols are 001 000 . That is, it is hypothesized that the data sequence 111 101 001 000 has been transmitted as highlighted in a bold line in FIG. 3. The sequential hypothesizing as mentioned above is able to reduce the number of data sets (i.e., 111 , 001 , . . . along each branch) to be searched only two at each of the hypothesizing operations in this case.
[0013] As in the above case, assuming that the data sequence 111 101 001 000 has been transmitted. However, in this instance, it is assumed that due to more noisy channel circumstances, the received data sequence is contaminated as 010 101 001 000 . In such a case, it is hypothesized that the first three symbols are 000 due to the shorter Hamming distance. Since this hypothesis is correct, it follows that the following code symbols are hypothesized as 111 101 001 . Thus, the data sequence received is hypothesized as 000 111 101 001 as indicated by a phantom line in FIG. 3. In this case, however, 4 symbol (bits) are erroneously presumed. This implies that once an erroneous hypothesis is made, the subsequently decoded symbols tend to be rendered uncorrelative or irrelevant with the received data sequence.
[0014] Throughout the instant disclosure, a term “path” implies a trail or passage from the origin node to a certain point (node) in the tree, or the most likely path up to a certain terminal node in the tree (viz., solution of the decoder). Further, a partial sequence x j denotes a path at j-th level in the code tree as shown in FIG. 3. As will be understood, the number of paths at the level 1 (viz., x 1 ) is two, and that at the level 2 (viz., x 2 ) is four, and so on. However, the partial sequences at the same level will not be discriminated with one another in the following descriptions.
[0015] In FIG. 3, a plurality of nodes in the code tree are denoted by n 0 , n 1 (1), n 1 (2), n 2 (1), . . . , n 4 (15), and n 4 (16), while a plurality of branches in the tree are denoted by b 1 (1), b 1 (2), . . . , b 4 (15), and b 4 (16).
[0016] The decoder is configured such as to notice that if the decoded data symbols are found to deviate from those of the received data sequence in excess of a predetermined threshold, the previous hypothesis has been erroneous. More specifically, if the decoder notices that the earlier hypothesis is erroneous at a given preceding node, the decoder returns to this node, changing the suspected branch (or node), and proceeds along a new branch or path in the tree. Each of these successive hypotheses is able to reduce the number of selections to be checked, simplifying the succeeding hypothesizing operations, and being able to give the information via which the correctness of earlier hypothesis can be determined.
[0017] FIGS. 4 A- 4 C are diagrams schematically illustrating a set of rules according to the sequential decoding algorithm, which rules consists of three kinds of moves: forward, lateral, and backward of the decoder (or the moves of a pointer). On the forward move (FIG. 4A), the decoder advances the pointer along one branch b 2 (1) to the right in the code tree from the previously hypothesized node. The lateral move (FIG. 4B) is a move from one node b 2 (1) to another b 2 (2). In more specific term, on the lateral move, the pointer moves backward to the node from which the branch b 2 (1) stems, after which the pointer advances along the node b 2 (2). The backward move (FIG. 4( c )) is that the decoder retreats the pointer along one branch b 2 (2) to the previously examined branch b 1 (1) in the code tree.
[0018] The principle of the Fano algorithm is described in a paper entitled “A Heuristic Discussion of Probabilistic Decoding” by Robert M. Fano, IEEE Transactions of Information Theory, Vol. IT-9, p. 64-74, April 1963, or a book entitled “Information Theory and Reliable Communication” by Robert G. Gallager, John Wiley & Sons, Inc., 1968.
[0019] As to the history of the sequential decoding, reference should be made, for example, to a paper entitled “Backtrack Programming” by Solomon W. Golomb and Leonard D. Baumert, Journal of the Association for Computing Machinery, Vol. 12, No. 4, pp. 516-524, October 1965.
[0020] Prior to implementing the sequential decoding, the decoder previously stores the code tree which is a replica of that in an encoder and has been exemplified in FIG. 3. The code tree stored in the decoder typically takes the form of a look-up table which includes a plurality of branches (or nodes) with the logical relationship therebetween. That is to say, the branches (or nodes) can be specified using memory addresses each of which may be referred to as the pointer in the instant disclosure.
[0021] As mentioned above, the Fano algorithm is to decode the inputted data sequence, which can be represented in a tree structure, by discarding an improbable path (node or branch) and search new one through the code tree.
[0022] The Fano algorithm however is in fact more complicate. FIG. 5 is a table showing the operation rules of the conventional Fano algorithm, which table is given in the aforesaid book by Galleger. In FIG. 5, T denotes a threshold, and Γ denotes a path metric called the Fano metric and is given by
Γ(x i )=−log{p(y)/p(y|x j )}−B(x j−1 ) (1)
[0023] where p(y) is a probability of occurrence of an inputted data sequence y in the tree, p(y|x j ) is a probability of occurrence of the data sequence y under the condition that a path x j of length (or depth) j in the tree occurs, and p(x j ) is a probability of occurrence of the path x j of length j in the tree. Further, B(x j−1 ) of equation (1) represents a bias in connection with the path x j−1 in the tree, and is selected such that if x j is a path forming part of the maximum likelihood (most likely) path, the expected value of Γ(x j ) becomes positive, and otherwise, the expected value of Γ(x j ) becomes negative.
[0024] Further, in FIG. 5, the character “I” denotes increment of the threshold T. More specifically, “I” implies that the threshold T is incremented by t 66 (viz., T=T+tΔ) where t is the maximum integer satisfying Γ(x j )−Δ<T+tΔ≦Γ(x j ). Still further, the character “N” represents no change of the threshold T, and “D” the decrement of the threshold T (viz. T=T−Δ). Still further, in FIG. 5, “F” denotes a forward move of the pointer so as to examine a subsequent branch or node in the code tree, “L” a lateral move of the pointer, and “B” a backward move of the pointer.
[0025] As is well known in the art, according to the Fano algorithm, the decoder will move forward through the code tree as long as the metric value along a path being examined continues to increase. When the metric value falls below a threshold, the decoder retreats and starts to examine other path leaving the same node. If no path stemming from the same node can be found whose path metric exceeds the threshold, the threshold is decreased and the decoder attempts to move forward again with a decreased threshold. No node (or branch) is ever examined twice with the same threshold, and accordingly, the decoder is not trapped in a loop.
[0026] It is understood, from the just-mentioned brief descriptions of the Fano algorithm, that this algorithm is able to markedly improve the process time compared to unconditionally checking all nodes (or branches). Therefore, the Fano algorithm has found extensive application in the filed of error control decoding. As an example of a practical use of the Fano algorithm, reference should be made to U.S. Pat. No. 3,665,396.
[0027] It is known in the art that if a code rate R is smaller than a computational cutoff rate R comp , the average time of computation, needed to search the most likely path through the code tree in the Fano algorithm, is proportional to the length N(x) of the most likely path. The code rate R is a ratio of the number of bits needed to represent one symbol of information sequence (viz., input to an encoder) to the number of bits needed to represent one symbol of data sequence (viz., output of the encoder). On the other hand, the computational cutoff rate R comp is determined depending on the above-mentioned probabilities p(y), p(y|x j ) and p(x j ) and is a little bit smaller than an entropy H of the information symbol sequence.
[0028] However, the conventional Fano algorithm has encountered the difficulties that provided that the paths in the code tree do not occur equiprobably, it is often the case that the average time of computation until determining the most likely path in the tree, is not proportional to the length (N(x)) of the most likely path and thus liable to diverge. This is because if the paths in the code tree do not occur equiprobably, the value corresponding to the entropy H of the information symbol sequence becomes smaller, thereby lowering the computational cutoff rate R comp . Further, if the value corresponding to the code rate R becomes larger than that corresponding to R comp , the average time of computation for searching the most likely path in the tree is no longer proportional to the length N(x) thereof, and thus resulting in the fact that the number of computing processes diverges. In practice, however, since the number of the paths in the code tree is finite, such a problem of divergence may be somewhat rare. Nonetheless, in the case where the paths in the code tree do not occur equiprobably, the amount of computation increases to an extent of practically unacceptable level.
[0029] Accordingly, the conventional Fano algorithm has not ever been applied to the technical fields such as pattern recognition, speech recognition, etc. wherein the paths in the code tree occur equiprobably.
SUMMARY OF THE INVENTION
[0030] It is therefore an object of the present invention to provide a sequential decoding apparatus which is well suited to decode an incoming data sequence in an application such as pattern recognition, speech recognition, etc. wherein the partial sequences in the code tree do not occur equiprobably.
[0031] Another object of the present invention is to provide a sequential decoding method which is well suited to decode an incoming data sequence in an application such as pattern recognition, speech recognition, etc. wherein the partial sequences in the code tree do not occur equiprobably.
[0032] In brief, these objects are achieved by the techniques wherein in order to sequentially decode a plurality of symbol sets of an incoming data sequence with less amount of computation in an application wherein paths in a code tree do not occur equiprobably, a code tree is previously memorized in a decoder. This code tree comprises a plurality of paths defined by a plurality of sequences of nodes. A pointer generator is provided for generating a pointer that defines a node that specifies a path in the code tree. A plurality of branch metric generators each generates a metric of a branch which forms part of a path and which is to be examined with a corresponding symbol set of the incoming data sequence. Further, a plurality of path metric generators are provided which respectively receive the branch metrics from the plurality of branch metric generators and respectively generate path metrics using the branch metrics. A controller controls the pointer generator and the plurality of path metric generators such as to maximize each of the plurality of path metrics at each of decoding steps for sequentially decoding the symbol sets of the incoming data sequence.
[0033] One aspect of the present invention resides in an apparatus for sequentially decoding a plurality of symbol sets of an incoming data sequence. The apparatus comprises a memory for storing a code tree which comprises a plurality of paths defined by a plurality of sequences of nodes. A pointer generator is provided for generating a pointer which defines a node which specifies a path in the code tree. A plurality of branch metric generators are also provided, each of which generates a metric of a branch which forms part of a path and which is to be examined with a corresponding symbol set of the incoming data sequence. A plurality of path metric generators respectively receive the branch metrics from the plurality of branch metric generators and respectively generate path metrics using the branch metrics. A controller controls the pointer generator and the plurality of path metric generators such as to maximize each of the plurality of path metrics at each of decoding steps for sequentially decoding the symbol sets of the incoming data sequence.
[0034] Another aspect of the present invention resided in a method sequentially decoding a plurality of symbol sets of an incoming data sequence by way of data search through a code tree stored in a memory. The code tree comprises a plurality of paths defined by a plurality of sequences of nodes. The method includes the steps of: (a) generating a pointer which defines a node which specifies a path in the code tree; (b) generating a plurality of branch metrics each of which relates to a branch which forms part of a path and which is to be examined with a corresponding symbol set of the incoming data sequence; (c) determining a plurality of path metrics using the plurality of branch metrics; and (d) controlling the generation of the pointer and the determination of the plurality of path metrics such as to maximize each of the plurality of path metrics at each of decoding steps for sequentially decoding the symbol sets of the incoming data sequence.
BRIEF DESCRIPTION OF THE DRAWINGS
[0035] The features and advantages of the present invention will become more clearly appreciated from the following description taken in conjunction with the accompanying drawings in which like elements or portions are denoted by like reference numerals and in which:
[0036] [0036]FIG. 1 is a block diagram schematically showing one example of convolutional encoder, this figure having been referred to in the opening paragraphs of the instant disclosure;
[0037] [0037]FIG. 2 is a diagram schematically showing a code tree for use in describing the operation of the encoder of FIG. 1;
[0038] [0038]FIG. 3 is a diagram schematically showing a code tree, which is a replica of the code tree of FIG. 2 and which is used in a decoder;
[0039] FIGS. 4 A- 4 C are diagrams showing pointer's moves in the decoder according to the conventional Fano algorithm;
[0040] [0040]FIG. 5 is a diagram showing operation rules of the conventional Fano algorithm;
[0041] [0041]FIG. 6 is a diagram showing operation rules of the sequential decoding algorithm according to a first embodiment of the present invention;
[0042] FIGS. 7 A- 7 B are diagrams schematically showing that the sequential decoding algorithm according to the first embodiment of the present invention is not trapped in a loop;
[0043] [0043]FIG. 8 is a flow chart which shows the steps which characterize the sequential decoding according to the first embodiment of the present invention;
[0044] [0044]FIG. 9 is a block diagram schematically showing one example of the sequential decoder according to the first embodiment of the present invention;
[0045] [0045]FIG. 10 is a block diagram showing one block of the decoder of FIG. 9 in detail;
[0046] [0046]FIG. 11 is a flow chart which shows the steps which characterize the operation of a controller that forms part of the sequential decoder of FIG. 9;
[0047] [0047]FIG. 12 is a block diagram showing another block in detail which forms part of the sequential decoder of FIG. 9;
[0048] [0048]FIG. 13 is a diagram showing operations of another block in detail that forms part of the sequential decoder of FIG. 9;
[0049] [0049]FIG. 14 is a functional table showing the operation of another block which forms part of the sequential decoder of FIG. 9 in detail;
[0050] [0050]FIG. 15 is a block diagram schematically showing one example of the sequential decoder according to the second embodiment of the present invention;
[0051] [0051]FIG. 16 is a flow chart which shows the steps which characterize the sequential decoding according to the second embodiment of the present invention;
[0052] [0052]FIG. 17 is a block diagram schematically showing one example of the sequential decoder according to the second embodiment of the present invention;
[0053] [0053]FIG. 18 is a flow chart which shows the steps which characterize the operation of a controller that forms part of the sequential decoder of FIG. 17; and
[0054] [0054]FIG. 19 is a functional table showing the operation of another block which forms part of the sequential decoder of FIG. 17 in detail.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0055] Before turning to a first embodiment of the invention, the principle underlying the present invention will be described. According to the present invention, a new path metric is introduced into the Fano algorithm in addition to the conventional Fano metric, which new path metric will be referred to a second (path) metric. A path search through the code tree is implemented such as to maximize the Fano metric and the second metric together at each decoding step (viz., step for decoding one symbol set of incoming data sequence). The Fano metric, which will be denoted by Γ 1 in the following description, is identical to that of equation (1) and thus given by
Γ 1 (x i )=−log {p(y)/p(y|x j )}−B 1 (x j-1 ) (2)
[0056] The first and second terms of equation (2) have already been referred to in the opening paragraphs and hence further descriptions thereof will be omitted for brevity.
[0057] In the conventional Fano algorithm, a path whose metric has a large value in terms of log {p(y)/p(y|x j )} (equation (2)) is preferentially searched under the condition that the bias B(x j−1 ) is properly selected. In order to enhance or improve this preferential tree search of the conventional Fano algorithm so as to meet the situation wherein the paths to be searched do not occur equiprobably, the invention adopts the second path metric Γ 2 (x i ) as set forth below.
Γ 2 (x i )=log {p(x j )}−B 2 (x j−1 ) (3)
[0058] where p(x j ) represents a probability of occurrence of a path x j , in the code tree, and B 2 (x j−1 ) is a bias corresponding to B 1 (x j−1 ). More specifically, the bias B 2 (x j−1 ) is selected such that an expected value of Γ 2 (x i ) becomes positive if x j is a partial sequence of the most likely path, and becomes negative if x j is a partial sequence of an improbable path.
[0059] Clearly, in the case where p(x j ) exhibits a large value, the value of the first term “log {p(x j )}” of equation (3) becomes large as well. As such, if a path search through the code tree is implemented so as to maximize the two path metrics Γ 1 and Γ 2 at each decoding step, the most likely path tends to be searched in a preferential manner because - log {p(y)/p(y|x j )} (equation (2)) and log {p(x j )} (equations (3)) respectively exhibit large values at each decoding step. In other words, in accordance with the present invention, even if the paths in the code tree do not occur equiprobably, an attempt to search the most likely path in the tree can effectively be carried out with extensively small amount of computations relative to the conventional Fano algorithm.
[0060] However, it is not easy to determine the actual rules of tree search for practically performing the underlying principle of the invention thus far mentioned. This is because, according to the conventional Fano algorithm, only a single action can be implemented at a time, and thus it is unable to independently change the two pairs of metric and threshold (i.e., ( Γ 1 , T 1 ) and (Γ 2 , T 2 )). In addition, it appears intuitively that the maximization of these two pairs at each of the decoding steps might boost the number of operation rules to a practically unacceptable extent.
[0061] Fortunately, however, there exist some clues that serve to determine the rules of the tree search via which the principle of the present invention can practically be realized. One of the clues is that the tree search at each decoding step (i.e., step for decoding one symbol set of the received data sequence), which accompanies the concurrent maximization of the two metrics Γ 1 and Γ 2 , is an extension of the conventional Fano algorithm. Therefore, if one of the two metrics Γ 1 and Γ 2 increases monotonously, the rules of the tree search becomes identical to those of the conventional Fano algorithm. Another clue is that since the two metrics Γ 1 and Γ 2 are maximized at each decoding step (in other words, since Γ 1 and Γ 2 are equivalent with each other), the rules of the tree search should be symmetrical with respect to Γ 1 and Γ 2 , which implies that the rules should remain unchanged even if Γ 1 and Γ 2 are exchanged.
[0062] After several efforts on a trial-and-error basis in order to practically realize the aforesaid principle of the invention, the inventors determined the rules of tree search for finding out the most likely path while maximizing the two metrics Γ 1 and Γ 2 at each decoding step in the environments wherein the paths do not occur equiprobably. The tree search rules thus determined are shown in FIG. 6, which are arranged in a manner similar to that of FIG. 5. The operation rules listed in FIG. 6 can be understood without difficulty from the foregoing descriptions of FIG. 5.
[0063] It will be described, with reference to FIGS. 7A and 7B, that the tree search, which is performed according to the rules shown in FIG. 6, can be implemented without being trapped in a loop. In FIGS. 7A and 7B, the vertical and horizontal axes respectively denote the path metric and the depth in the tree, a zigzag line denoting a sequence of branches (or nodes) in the tree, and each of horizontal solid and phantom lines indicates the threshold T 1 .
[0064] Referring to FIG. 7A, one example of the tree search is illustrated with the threshold T 2 remaining unchanged. The decoder moves forward the pointer from node n 3 to n 4 with increment of threshold T 1 according to Rule 1 . 1 of FIG. 8. Thereafter, the decoder further moves forward the pointer from node n 7 to n 8 with increment of threshold T 1 by Δ 1 . Following this, the decoder moves backward the pointer from the node n 8 to n 3 , after which the pointer again moves forward from node n 3 to n 4 with the threshold T 1 being lowered by Δ 1 and again goes to node n 8 by way of nodes n 4 -n 7 . In this case, the branch b 7 is reexamined with the threshold T 1 that is different from the previous value of T 1 , and accordingly, it is possible to prevent the algorithm from being trapped in a loop as in the conventional Fano algorithm.
[0065] [0065]FIG. 7B shows another example of the tree search. In this instance, as in the case of FIG. 7A, assuming that the decoder moves forward the pointer from node n 3 to n 4 while increasing the threshold T 1 according to Rule 1 . 1 of FIG. 8, and thereafter, the decoder further moves forward the pointer from node n 7 to n 8 with increment of threshold T 1 by Δ 1 . Subsequently, the decoder retreats the pointer from node n 8 to node n 5 , at which the decoder again advances the pointer from node n 5 to node n 6 while increasing the threshold T 2 in accordance with Rule 4 . 2 of FIG. 6. In this case, the decoder reexamines branch b 7 using the same thresholds T 1 as in the previous search of branch b 7 . However, fortunately, as mentioned above, the threshold T 2 has been changed at the branch b 5 , and as such, the branch b 7 is reexamined with different threshold pair of T 1 and T 2 . To iterate, according to the present invention, no node (or branch) is ever examined twice with the same threshold pair (T 1 , T 2 ), and accordingly the algorithm is not trapped in a loop.
[0066] [0066]FIG. 8 is a flow chart which shows the steps which characterizes the sequential decoding according to the first embodiment of the invention. As shown in FIG. 8, the routine starts with step 30 , at which a decoder initializes the thresholds T 1 and T 2 to zero, and sets an address of the origin node to the pointer. Further, at step 30 , the decoder initializes the two path metrics Γ 1 and Γ 2 to zero. Although not shown in FIG. 8, at step 30 , the decoder then advances the pointer to one of the first nodes leaving from the origin node, and, at step 32 , calculates the two metrics Γ 1 (x j ) and Γ 2 (x j ). It is to be noted that the suffix “j” in the flow of FIG. 8 takes “b 1 ” until the routine returns to step 32 for the first time. Once the routine returns to step 32 , the suffix “j” is unable to be specified because the pointer moves forward or backward or laterally in the code tree. In order to simplify the description of FIG. 8 flow chart, the following processes begin with calculating Γ 1 (x i ) and Γ 2 (x i ).
[0067] As mentioned above, the pointer determines the path x i . Subsequently, the routine proceeds to step 34 at which a check is made to determine if the pointer reaches a terminal node and at the same time if Γ 1 (x i )≧T 1 and Γ 2 (x i )≧T 2 . If the inquiry made at step 34 is affirmative (YES), the routine terminates, and otherwise (NO), the routine proceeds to step 36 .
[0068] At step 36 , the comparison indicated in the table of FIG. 6 are implemented using Γ 1 (x i−1 ), Γ 1 (x i ), Γ 2 (x i−1 ), Γ 2 (x i ), T i , T 2 , Γ 1 , and Γ 2 , and the program goes to step 38 . At this step 38 , depending on the comparison results obtained at step 36 and on whether the pointer is able to move laterally, the decoder determines the values of the threshold levels T 1 and T 2 , and also determines the subsequent pointer's move (viz., forward, backward, or lateral). Following this, the routine advances to step 40 ( 1 ).
[0069] In the following, the three kinds of threshold changes are represented by “I”, “N”, and “D” which respectively indicate “increment”, “no-change” and “decrement” of the threshold. Further, the three kinds of pointer moves to be taken are indicated by “F”, “L”, and “B” which respectively depict “forward”, “lateral” and “backward”.
[0070] At step 40 ( 1 ), a check is made to determine as to which step the routine should proceed to among steps 42 ( 1 ), 44 ( 1 ), and 40 ( 2 ) depending on the result (i.e., “I”, “N” or “D”) decided at step 38 . If the decision made at step 40 ( 1 ) indicates that the routine goes to step 42 ( 1 ), the decoder lowers the threshold T 1 thereat according to Rule 4 . 1 of FIG. 6, after which the routine goes to step 40 ( 2 ). On the other hand, if decoder instructs that the routine goes to step 44 ( 1 ) on the basis of the result at step 38 , the decoder raises, at this step, the threshold T 1 in accordance with Rule 1 . 1 .
[0071] If the decision made at step 40 ( 1 ) instructs the routine to proceed to step 40 ( 2 ), no change occurs in the value of T 1 . The procedures, which are substantially identical to those at steps 40 ( 1 ), 42 ( 1 ), and 44 ( 1 ), are implemented at steps 40 ( 2 ), 42 ( 2 ), and 44 ( 2 ) in terms of the threshold T 2 . If the decision made at step 40 ( 2 ) indicates that the routine goes to step 42 ( 2 ), the decoder decreases the threshold T 2 thereat according to Rule 4 . 2 of FIG. 6, after which the routine goes to step 46 . On the other hand, if decoder instructs that the routine goes to step 44 ( 2 ) according to the result obtained at step 38 , the decoder increases, at this step, the threshold T 2 in accordance with one of Rule 1 . 2 .
[0072] As mentioned above, since the two pairs of metric and threshold are used, two step blocks are necessary, one of which includes steps 40 ( 1 ), 42 ( 1 ), 44 ( 1 ) and the other includes steps 40 ( 2 ), 42 ( 2 ) and 44 ( 2 ). Subsequently, at step 46 , a check is made to determine as to which step the routine should go to among steps 48 , 50 , 52 in accordance with the result at step 38 . At step 48 , the pointer moves backward, after which the program returns to step 32 via step 54 at which “j” is changed. At step 50 , the pointer moves laterally and subsequently the routine returns to step 32 via step 54 , in the case of which a branch is changed in the same depth in the tree. Further, at step 52 , the pointer moves forward and the routine goes back to step 32 via step 54 .
[0073] [0073]FIG. 9 is a block diagram schematically showing a sequential decoder (depicted by reference numeral 70 ) according to the first embodiment of the invention. A controller 72 is provided to supervise the overall operation of the decoder 70 using a program stored in an appropriate memory (not shown). For the sake of simplifying the drawing, some of control and data lines extending from the controller 72 to the blocks are omitted in the figure.
[0074] In FIG. 9, a data sequence y is applied, via an input terminal 74 , to two branch metric generators 76 1 and 76 2 . A memory 78 , which typically takes the form of read-only-memory (ROM), previously stores a code tree such as shown in FIG. 3 (for example). A pointer generator 80 , in response to an address control signal from the controller 72 , supplies the memory 87 with a pointer, which indicates an address of node in the code tree and thus specifies a path in the tree. The memory 78 is responsive to the pointer applied thereto and outputs the data of the path x j (j=1, 2, . . . , j) defined by the pointer. The data of the path x j thus derived from the memory 78 is applied to the branch metric generators 76 1 and 76 2 and also to an output terminal 82 . As an alternative, it is possible to apply the branch, defined by the pointer, to the branch metric generators 76 1 and 76 2 as will be understood as the description proceeds.
[0075] The pointer generator 80 comprises a register for temporarily storing the pointer (viz., address) and a suitable memory such as a ROM (neither shown). This memory provided in the pointer generator 80 previously stores a plurality of addresses which respectively indicate the nodes of the code tree stored in the memory 78 . The pointer generator 80 operates such as to control the pointer's move (viz., forward, lateral, or backward) according to the control signal applied thereto from the controller 72 .
[0076] Since each of the blocks 78 and 80 is of conventional type and well known in the art, the details thereof will not be given to simplify the description of the instant disclosure. For details, reference should be made, for example, to a book entitled “Data Abstraction and Problem Solving With C++, Walls and Mirrors” by Frank M. Carrano, published 1995 by The Benjamin/Cummings Publishing Company, Inc., Redwood City, Calif. 94065.
[0077] A lateral move indicating signal generator 84 is provided such as to receive the pointer from the pointer generator 80 and determines if the pointer is able to move laterally. If the lateral move of the pointer is possible, the generator 84 issues a logic level 1 (for example), and otherwise, outputs a logic level 0 , which logic level ( 1 or 0 ) is fed to an operation determiner 86 as a lateral move indicating signal.
[0078] The lateral move indicating signal generator 84 can be configured using straightforward logic circuitry in the even that the pointer is provided with a predetermined number of lower bits whose logic levels are set as follows. Provided that a branch stemming from a given node is the last one to be examined, the lower bits of the pointer are all set to logic level 1 s, and otherwise, at least one bit of the predetermined lower bits is set to logic level 0 with all the remaining ones being set to logic level 0 s. With the change of the lower bits depending on the aforesaid situation, the generator 84 can be configured so as to compute NAND of the above-mentioned predetermined lower bits.
[0079] In order to simplify the following description, a suffix k is used to denote two blocks or two metric values (viz., k=1, 2), or to denote one of them (k=1 or 2). As mentioned above, the branch metric generators 76 k are supplied with a set of data symbols of the inputted data sequence y through the input terminal 74 , the data of path x j (or branch data corresponding to the set of inputted data symbols) from the code tree memory 78 . The computation results γ k (x j ) obtained at the branch metric generators 76 k are respectively applied to path metric generators 88 k (k=1, 2).
[0080] In order to automatically prevent the pointer from further retreating when returning to the origin node, it is preferable to introduce γ 1 (NULL) and γ 2 (NULL) each of which is a sufficiently large value wherein NULL indicates data of length 0.
[0081] Since each of the path metric generators 88 k has already stored therein the previously calculated path metric Γ k (x j−1 ), it is possible for each of the generators 88 k to obtain or calculate a new path metric using the corresponding branch metric applied thereto, the detail of which will be described later. The path metrics Γ k (x i ) and Γ k (x i−1 ) determined at each of the generators 88 k are applied to a corresponding comparator 90 k (k=1 or 2), while the path metric Γ k (x i ) is applied to a corresponding threshold generator 92 k (k=1 or 2).
[0082] Each of the threshold generators 92 k , in addition to the above-mentioned path metric Γ k (x i ), receives a selector control signal indicative of “decrement”, “no-change” or “increment” of threshold in connection with the current decoding step from the operation determiner 86 . The selection control signal has been stored in a register 94 . Further, each of the threshold generators 92 k is supplied with a control signal from the controller 72 , which also will be described later in connection with FIG. 12. Subsequently, each of the threshold generators 92 k generates the threshold T k (k=1 or 2) which is applied to the corresponding comparator 90 k .
[0083] The comparators 90 k respectively carry out the following comparisons
Γ k (x i−1 )<T k (4)
Γ k (x i−1 )<T k +Δ k (5)
Γ k (x i )≧T k (6)
[0084] All of these three comparison results are applied to the operation determiner 86 , while the comparison result Γ k (x i )≧T k is fed to the controller 72 .
[0085] Summing up, the operation determiner 86 is supplied with the following information: the lateral move indicating signal from the generator 84 , the three kinds of comparison results from the comparators 90 k . The operation determiner 86 further receives the pointer's move at the current decoding step from the register 94 . Subsequently, the operation determiner 86 , using the above-mentioned data applied thereto, decides the operation to be taken (viz., the change of threshold T k and the pointer's move). The data indicating the next operation, decided at the operation determiner 86 , is stored in the register 94 .
[0086] Before the decoder 70 of FIG. 9 starts sequential decoding of an incoming data sequence y, the register 94 is supplied with a clock pulse from the controller 72 while receiving a logic level 0 at a CLR terminal from the controller 72 , whereby the register 94 is initialized such as to store a control data indicating the forward move of the pointer. On the other hand, after starting the sequential decoding, when the register 94 receives a clock pulse while receiving a logic level 1 at CLR terminal, both from the controller 72 , the register 94 stores the data indicating the next operation generated from the operation determiner 86 .
[0087] The controller 72 is supplied with the above-mentioned data from the comparators 92 k and the operation determiner 86 , and applies the control signals to the pointer generator 80 , the path metric generators 88 k , the threshold generators 92 k , and the register 94 , which will further be described later. When the controller 72 terminates the operation thereof, the most likely path x is derived from the output terminal 82 .
[0088] Reference is made to FIGS. 10 and 11. FIG. 10 is a block diagram showing one example of the path metric generator 88 1 , in terms of the configuration thereof. The other path metric generator 88 2 is configured in exactly the same manner as 88 1 . On the other hand, FIG. 11 is a flow chart showing the steps that depict the operation of the controller 72 focusing primarily on the control of path metric generator 88 1 of FIG. 10.
[0089] Before turning to FIG. 10, steps 120 , 122 , and 124 of FIG. 11 will first be described. As in the above, x j denotes the path defined by the pointer, and a suffix k is used to denote two metric values for the sake of simplifying the disclosure.
[0090] In FIG. 11, the routine starts with step 120 . At this step 120 , an address, which specifies the origin node of the tree code, is set to the pointer generator 80 (FIG. 9). Further, at step 120 , the controller 72 applies a logic level 0 (clear signal) to the path metric generators 88 k , the threshold generators 92 k , and the register 94 . Still further, at step 120 , the controller 72 applies one clock to the above-mentioned blocks 88 k , 92 k , and 94 while applying the logic level 0 thereto, thereby initializing them. Still further, at step 120 , the controller 72 continues to apply a logic level 1 (enable signal) to the blocks 88 k , 92 k , and 94 in order to maintain the enable states thereof. Thereafter, the routine goes to step 122 . At step 122 , a check is made to determine if the pointer reaches a terminal node and if Γ 1 (x j )≧T 1 and Γ 2 (x j )≧T 2 . If the inquiry made at step 122 is affirmative, the routine terminates, and otherwise (if negative), the routine proceeds to step 124 at which the routine branches out, depending on the pointer control signal (i.e., indicating “B”, “L” or “F”) applied from the operation determiner 86 , to one of steps 126 , 130 , or 138 .
[0091] Returning to FIG. 10, the path metric generator 88 1 receives the branch metric γ 1 (x j ) and then outputs the two path metrics Γ 1 (x j−1 ) and Γ 1 (x j ). It is to be noted that x j and x j−1 merely indicate a relative relationship between the input and output of the generator 88 1 . That is to say, since the pointer moves backward and forward in the code tree, the branch metric may change from y γ 1 (x j ) (as indicated in FIG. 10) to γ 1 (x j−1 ) or γ 1 (x j+1 ), in the case of which the path generator 88 1 issues “Γ 1 (x j−2 ) and Γ 1 (x j−1 )” or “Γ 1 (x j ) and Γ 1 (x j+1 )”. It is deemed advantageous to divide the operations of the path metric generator 88 1 according to the three different moves of the pointer, viz., (a) backward move, (b) forward move, and (c) lateral move.
[0092] (a) In the case of moving backward the pointer:
[0093] A register 106 has already stored a path metric Γ 1 (x j ) which has been determined during the preceding decoding step. A branch metric γ 1 (x j ), which has also been determined during the preceding decoding step, is being applied to a subtracter 102 and an adder 104 via an input terminal 100 . In such a case, the output of the subtracter 102 , Γ 1 (x j−1 ) (=γ 1 (x j )−γ 1 (x j )), is applied to the comparator 90 1 via an output terminal 112 . However, at this stage, the comparator 90 1 neglects the path metric Γ 1 (x j−1 ) fed thereto. Subsequently, the controller 72 supplies a selector 110 with a selector control signal SEL indicating “backward move of pointer (B)”, in response to which the selector 110 selects the output of the subtracter 102 (Γ 1 (x j−1 )=Γ 1 (x j )−γ 1 (x j )), and thereafter, the controller 72 applies a clock to the register 106 , in response to which the register 106 acquires the output of the subtracter 102 (Γ 1 (x j−1 ))(step 126 of FIG. 11). Therefore, the content of register 106 is renewed from Γ 1 (x j ) to Γ 1 (x j−1 ), and the renewed path metric Γ 1 (x j−1 ) is applied to the comparator 90 1 and the threshold generator 92 1 . Following this, the controller 72 moves backward the pointer (step 128 of FIG. 11), whereby a branch metric γ 1 (x j−1 ) is determined at the branch metric generator 76 1 , and applied to the path metric generator 88 1 via the input terminal 100 . As a result, the subtracter 102 changes the output thereof from Γ 1 (x j−1 ) to Γ 1 (x j−2 ) which is applied to the comparator 90 1 and acknowledged thereby.
[0094] (b) In the case of moving forward the pointer:
[0095] As in the above case (a), the register 106 has already stored the path metric Γ 1 (x j ) which has been determined during the preceding decoding step. Further, the branch metric γ 1 (x j ), which has also been determined during the preceding decoding step, is being applied to the subtracter 102 and the adder 104 via the input terminal 100 . Thereafter, the controller 72 moves forward the pointer (step 138 of FIG. 11), whereby a branch metric γ 1 (x j+1 ) is determined at the branch metric generator 76 1 and applied to the path metric generator 88 1 via the input terminal 100 . Subsequently, the controller 72 supplies the selector 110 with the selector control signal SEL indicating “forward move of pointer (F)”, in response to which the selector 110 selects the output of the adder 104 (Γ 1 (x j+1 )=Γ 1 (x j )+γ 1 (x j+1 )), and thereafter, the controller 72 applies a clock to the register 106 , in response to which the register 106 acquires the output of the adder 104 (Γ 1 (x j+1 ))(step 140 of FIG. 11). Therefore, the content of register 106 is renewed from Γ 1 (x j ) to Γ 1 (x j+ ), and the renewed path metric Γ 1 (x j+1 ) is applied to the comparator 90 1 and the threshold generator 92 1 . Further, the output of the subtracter 102 becomes Γ 1 (x j ) (=Γ 1 (x j+1 ) γ 1 (x j+1 )), which is applied to the comparator 90 1 via the output terminal 112 .
[0096] (c) In the case of laterally moving the pointer:
[0097] This case is substantially the combination of the above-mentioned two cases (a) and (b). As in the above case (a) or (b), the register 106 has already stored the path metric Γ 1 (x j ) which has been determined during the preceding decoding step. Further, the branch metric γ 1 (x j ), which has also been determined during the preceding decoding step, is being applied to the subtracter 102 and the adder 104 via the input terminal 100 . Subsequently, the controller 72 supplies a selector 110 with the selector control signal SEL indicating “backward move of pointer (B)”, in response to which the selector 110 selects the output of the subtracter 102 (Γ 1 (x j−1 )=Γ 1 (x j )−γ 1 (x j )), and thereafter, the controller 72 applies a clock to the register 106 , in response to which the register 106 acquires the output of the subtracter 102 (Γ 1 (x j−1 ))(step 130 of FIG. 11). Following this, the controller 72 moves backward the pointer (step 132 of FIG. 11), after which the controller 72 moves forward the pointer (step 134 of FIG. 11). Therefore, the branch metric γ 1 (x j ) is determined at the branch metric generator 76 1 and applied to the path metric generator 88 1 via the input terminal 100 . It should be noted that the just-mentioned branch metric γ 1 (x j ) differs from the initially mentioned branch metric γ 1 (x j ) because the former branch is different from the latter branch although both stem from the same node. Subsequently, the controller 72 supplies the selector 110 with the selector control signal SEL indicating “forward move of pointer (F)”, in response to which the selector 110 selects the output of the adder 104 (Γ 1 (x j )=γ 1 (x j−1 )+Γ 1 (x j )), and thereafter, the controller 72 applies a clock to the register 106 , in response to which the register 106 acquires the output of the adder 104 (Γ 1 (x j ))(step 136 of FIG. 11). Therefore, the content of register 106 is renewed from Γ 1 (x j ) to Γ 1 (x j ) (since the branch is different, these two path metrics Γ 1 (x j ) are different), and the renewed path metric Γ 1 (x j ) is applied to the comparator 90 1 and the threshold generator 92 1. Further, the output of the subtracter 102 becomes Γ 1 (x j−1 ) (=Γ 1 (x j )−γ 1 (x j )), which is applied to the comparator 90 1 via the output terminal 112 .
[0098] [0098]FIG. 12 is a diagram which shows the threshold generator 92 1 in detail in block diagram form. The other threshold generator 92 2 is configured in exactly the same manner as the generator 92 1 . A register 200 , which is provided to temporarily store a threshold T 1 , is initialized to zero (viz., T 1 =0) in response a clock pulse CLK applied thereto from the controller 72 via an input terminal 204 while receiving a logic level 0 (clear signal) from the controller 72 via an input terminal 206 . On the other hand, the register 200 retains the value fed thereto from a selector 202 in response to the clock pulse CLK while receiving a logic level 1 (enable signal) via the input terminal 206 .
[0099] Assuming that the register 200 has held therein the threshold T 1 applied thereto from the selector 202 . The threshold T 1 thus stored in the register 200 is applied to the selector 202 , a subtracter 208 , and an output terminal 210 coupled to the comparator 90 1 . The subtracter 208 subtracts the predetermined threshold spacing Δ 1 from the threshold T 1 , and applies the computation result (T 1 −Δ 1 ) to the selector 202 . An adder 212 is supplied with the path metric Γ 1 (x j ) from the path metric 88 1 via an input terminal 214 and the threshold spacing Δ 1 , and determines an integer t 1 that exhibits the maximum value satisfying
Γ 1 (x j )−Δ 1 <T 1 +t 1 ≦Γ 1 (x j )
[0100] and then applies T 1 +t 1 Δ 1 to the selector 202 . This selector 202 operates such as to select one of the three inputs in response to a selector control signal SEL, which is applied from the operation determiner 86 via an input terminal 214 and which instructs “increment (I)”, “decrement (D)” or “no-change (N)” of the threshold T 1 . The threshold T 1 thus selected by the selected 202 is stored in the register 200 , and also applied to the comparator 90 1 .
[0101] Referring to FIG. 13, the comparator 90 1 of FIG. 9 is broke down in terms of the configuration thereof and shown in block diagram form. The other comparator 90 2 is configured exactly in the same manner as the comparator 90 1. In FIG. 13, the path metric Γ 1 (x j−1 ) is applied from the path metric generator 88 1 to two comparators 250 and 252 via an input terminal 254 . Further, the threshold T 1 is applied to the comparator 250 , an adder 256 , and a comparator 258 by way of an input terminal 260 . Still further, the path metric Γ 1 (x j ) is applied to the comparator 258 from the path metric generator 88 1 via an input terminal 262 . The adder 256 adds the threshold T k and the threshold spacing Δ 1 , and applies the sum (T 1 +Δ 1 ) to the comparator 252 . The comparator 250 compares Γ 1 (x j−1 ) and T 1 , and applies the comparison result of whether Γ 1 (x j−1 )<T 1 to the operation determiner 86 by way of an output terminal 264 . Further, the comparator 252 compares Γ 1 (x j−1 ) and (T 1 +Δ 1 ), and applies the comparison result indicating if Γ 1 (x j−1 )<(T 1 +Δ 1 ) to the operation determiner 86 by way of an output terminal 266 . Still further, the comparator 258 compares Γ 1 (x j ) and T 1 , and applies the comparison result indicative of whether or not Γ 1 (x j )≧T 1 to the operation determiner 86 by way of an output terminal 268 and also to the controller 72 .
[0102] Reference is made to FIG. 14, there is shown an function table in connection of the operation determiner 86 . As shown, the operation determiner 86 receives three kinds of signals and data as follows. The first is the data indicative of the previous move of the pointer applied from the register 94 , the second is the comparison results applied from the comparators 90 k (k=1, 2), and the third is the lateral move indicating signal supplied from the generator 84 . Further, the operation determiner 86 issues three kinds of outputs. The first and second are respectively the threshold control signals via which the thresholds T 1 and T 2 are controlled, and the third is a pointer move control signal which indicates one of the three kinds of pointer's moves.
[0103] As mentioned above, “F”, “L” and “B” in the table are respectively indicative of the pointer's moves of “forward (F)”, “lateral (L)” and “backward (B)”, and “I”, “D”and “N” respectively indicate “Increment (I)”, “Decrement (D)” and “No-change (N)”of the threshold. The comparison results, received from the comparator 90 k (k=1, 2), are:
“Γ k (x j−1 )<T k ”, “Γ k (x j−1 )<(T k +Δ k )” and “Γ k (x j )≧T k ”
[0104] The logic level 0 , applied from the comparators 90 k, indicates that the corresponding inequality has not been established while the logic level 1 indicates that the corresponding inequality has been established. The logic levels “ 1 ” and “ 0 ” applied from the lateral move indicating signal generator 84 respectively represent that the lateral move of the pointer is possible and impossible.
[0105] The notation “-”, illustrated in the input side in the table, implies that the comparison result applied thereto is a don't-care one (viz., may take either 1 or 0). Further, the notation “-” shown at the output side represents that the threshold control depends on the condition of other row.
[0106] A second embodiment of the present invention will be described with reference to FIGS. 15 - 19 .
[0107] In the following, a combination of the above-mentioned p(y), p(y)/p(y|x j ), and p(x j ) is called a probability model. In an application using sequential decoding, different kind of probability models can be determined depending on which information is defined as one symbol of a data sequence. Accordingly, there can exist a plurality of probability models with one application. For example, in the technical field of speech recognition, it is possible to define a digital signal, which corresponds to each of the sampled values generated by converting an analog speech signal into the corresponding digital signal, as one symbol. In the first embodiment, a single probability model is treated and thus only two path metrics are used. However, the present invention is in no way limited to the case where only the two path metrics are used. That is, the present invention is applicable to more than two (denoted by “m”) pairs of path metric and threshold.
[0108] The number of “m” is determined as follows. Assuming that k denotes the total number of probability models to be used in a given application, and further assuming that the two path metrics are used with g (1≦g≦k) probability models, and the Fano metric is used with the remaining probability models whose number is k-g, then “m” becomes k+g. The present invention is to effectively reduce the number of paths to be examined depending on the probability of occurrence of the paths in the code tree. Therefore, it follows that if the number of paths to be examined can be reduced if the two path metrics are used with g probability models, then it is sufficient to use the Fano metric in connection with the remaining k-g probability models.
[0109] [0109]FIG. 15 is a diagram showing the rules for implementing the sequential decoding according to the second embodiment, which rules are listed or arranged in a manner similar to those shown in FIG. 6. The foot notes shown in FIG. 6 are applicable to the rules of FIG. 15, and thus they are omitted in FIG. 15 for the sake of simplifying the disclosure. As shown in FIG. 15, each of the numbers of rules 1 and 4 increases so as to meet the number of pairs of metric and threshold (viz., “m”) . Other than this, the rules of FIG. 15 are identical to those of FIG. 6. The rules of FIG. 15 are readily understood from the foregoing, and accordingly further descriptions thereof will be omitted for brevity.
[0110] According to the second embodiment, if a given node is revisited to be examined, the decoder advances the pointer to that node with a combination of thresholds (T 1 , T 2 , . . . , T m ) which is different on the previous visit. Therefore, the sequential decoding according to the second embodiment is not trapped in a loop as in the first embodiment.
[0111] [0111]FIG. 16 is a flow chart which shows the steps which characterize the sequential decoding according to the second embodiment. The procedure indicated in FIG. 16 is substantially identical to that in FIG. 8 expect that the former procedure is to handle more than two pairs of metric Γ 1 -Γ m and threshold T 1 -T m . Steps 330 - 352 of FIG. 16 are respectively similar or identical to steps 30 - 52 in FIG. 8. The second embodiment is an extension of the first embodiment, and thus, it will readily be understandable from the descriptions already made in connection with the first embodiment, and as such, further descriptions thereof will not be given for the sake of simplifying the disclosure.
[0112] [0112]FIG. 17 is a block diagram schematically showing one example of a sequential decoder (denoted by 70 ′) in accordance with the second embodiment. In the second embodiment, since the number of the path metrics and thresholds to be processed is more than two (viz. m>2), each of the numbers of branch and path metric generators, comparators, and the threshold generators is increased by m, accordingly. Other than this, the arrangement of FIG. 17 is substantially identical to that of FIG. 9, and hence, the reference numerals identical to those in FIG. 9 are used such that the branch metric generators, for example, are labeled 76 1 - 76 m . The operation of the sequential decoder 70 ′will be readily understandable from the foregoing descriptions already made in regard of the sequential decoder 70 of FIG. 9, and as such, the further descriptions thereof is deemed redundant and thus will be omitted for the sake of simplicity.
[0113] [0113]FIG. 18 is a flow chart which shows the steps which characterize the operation procedure of the controller 72 of FIG. 17. The operation procedure shown in FIG. 18 is substantially identical to that shown in FIG. 11 except that the former procedure treats more than three path metrics and thresholds. Since the detailed description of FIG. 18 is deemed redundant, and accordingly, further descriptions will not be given for simplifying the disclosure.
[0114] [0114]FIG. 19 is a diagram showing a function table that indicates the operations of the operation determiner 86 of FIG. 17, and corresponds to FIG. 14. The function of the operation determiner 86 of FIG. 17 will be clearly understood when referring to the descriptions of FIG. 14, and thus the detailed descriptions of FIG. 19 will be omitted.
[0115] Although the two embodiments have been discussed, it goes without saying that the present invention is not restricted thereto. For example, the embodiments have been described on the basis of the Fano algorithm recited in the above-mentioned book by Robert G. Gallager. However, the present invention can be made using any prior sequential decoding or any version of the Fano algorithm.
[0116] Still further, in the above descriptions, Γ k (x −1 ) is defined as -σ whereby it renders it unnecessary to advise the operation determiner 86 that the pointer has been returned to the origin node. It is however within the scope of the present invention to inform, without defining Γ k (x −1 )=-σ, the operation determiner 86 that the pointer has returned to the origin node, and determine the operation of the operation determiner 86 based on such information. Still further, it is possible to modify some of the operation rules shown in FIGS. 6 and 15. For example, the condition of Γ k (x 1 )≧T k can be replaced by Γ k (x j )≧T k +Δ k . This is because the increasing of the threshold T in the Fano algorithm is to implement the operation shown in Note 1 of FIG. 5, and accordingly, the increasing of the threshold T is carried out in the case of Γ l (x j−1 )<T+Δ and at the same time Γ k (x i )≧T+Δ.
[0117] Still further, in the above-mentioned embodiments, the next action to be taken is determined based on the metric Γ k and the threshold T k . However, it is readily understood that the next action to be taken is capable of being decided only on the basis of the value of Γ k −T k . If so modified, it is possible to reduce the number of registers, and further possible to prevent an overflow of each of the registers provided for storing Γ k and T k .
[0118] Still further, in the above-mentioned embodiments, the most likely path x is directly outputted from the output terminal 82 (FIGS. 9 and 17). As an alternative, it is possible to generate, as an output of the decoder, a predetermined code which corresponds to the most likely path x. In this case, it is necessary to previously prepare a plurality of codes which respectively correspond to a plurality of paths in the code tree.
[0119] The foregoing descriptions show only two preferred embodiments and some modifications thereof. However, other various modifications are apparent to those skilled in the art without departing from the scope of the present invention which is only limited by the appended claims. Therefore, the embodiments and modification shown and described are only illustrated, not restrictive. | Sequentially decoding a plurality of symbol sets of an incoming data sequence with less amount of computation in an application wherein paths in a code tree do not occur equiprobably is disclosed. A code tree is previously memorized which comprises a plurality of paths defined by a plurality of sequences of nodes. A pointer generator is provided for generating a pointer that defines a node that specifies a path in the code tree. A plurality of branch metric generators each generates a metric of a branch which forms part of a path and which is to be examined with a corresponding symbol set of the incoming data sequence. Further, a plurality of path metric generators are provided which respectively receive the branch metrics from the plurality of branch metric generators and respectively generate path metrics using the branch metrics. A controller controls the pointer generator and the plurality of path metric generators such as to maximize each of the plurality of path metrics at each of decoding steps in order to sequentially decode the symbol sets of said incoming data sequence. | 7 |
FIELD OF THE INVENTION
The present invention relates to ad hoc networks and, in particular, to a packet sniffer for an ad hoc network.
BACKGROUND OF THE INVENTION
Standard IEEE 802.11 packet monitors (or sniffers) are known. Such monitors may, for example, monitor RF traffic packet traffic.
Traditionally, network nodes in an ad hoc network connect to and participate in data communication using the ad hoc network. However, with respect to at least some ad hoc networks, such as those manufactured by the assignee of the instant patent application, Intech21, there does not exist the ability to receive data packets in an ad hoc network without connecting to the network.
SUMMARY OF THE INVENTION
A packet sniffer is a radio frequency (RF) device that receives data packets transmitted by devices on an ad-hoc network, such as Intech21's radio frequency ad-hoc network. Much like a standard IEEE 802.11 RF packet monitor, the packet sniffer monitors “sniffs” the air, recognizing and receiving RF packets transmitted by a compatible ad-hoc network node or device. The sniffer may also act as a mobile access point with selective communication features that would enable it to receive packets only from nodes of an ad-hoc network having certain hierarchical levels.
The packet sniffer advantageously obtains data packets from the network passively, i.e., without having to connect to and participate in the ad-hoc network. The packet sniffer transfers the information contained in the received packets to a personal computer (PC) or other device through the sniffer's interface. The PC typically contains software tools that can analyze the data to monitor and troubleshoot the ad-hoc network.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram of an ad-hoc network and sniffer in accordance with one embodiment of the present invention.
FIG. 2 is block diagram of an exemplary packet sniffer in accordance with one embodiment of the present invention.
FIG. 3 is a flow diagram describing the functionality of a sniffer in accordance with one embodiment of the present invention.
FIG. 4 is a flow diagram describing the transmission of FIFO packets in accordance with one embodiment of the present invention.
DETAILED DESCRIPTION
Referring to FIG. 1 , there is seen a packet sniffer 100 coupled to a computer 110 , such as a personal computer (“PC”) 110 . Packet sniffer 100 may be employed, for example, in an ad-hoc network 120 . Packet sniffer 100 receives data packets wirelessly transmitted via an RF communication link 130 by one or more nodes in ad-hoc network 120 , such as Intech21's radio frequency ad-hoc network. The packet sniffer 100 transfers the information contained in the received packets through an interface to computer 110 , such as PC 110 . The PC typically contains software tools that can analyze the data to monitor and troubleshoot the ad hoc network 300 .
Referring now to FIG. 2 , there is seen an exemplary packet sniffer 100 in accordance with one embodiment of the present invention. Packet sniffer 100 includes microprocessor 210 coupled to RF transceiver 200 , memory 220 coupled to microprocessor 210 , and a communications interface 230 coupled to memory 220 . In one embodiment, RF transceiver 200 is a TR1000 transceiver, which may be placed in a receive mode. Packet sniffer 100 also includes software, which may be copied from an external computer-readable medium (not shown) into memory 200 , that, when executed, causes microprocessor 210 to receive radio frequency information from at least one ad-hoc network 120 , select from the radio frequency information data packets originating from ad-hoc network 120 , and transfer the data packets to communications interface 230 for transmission to an external device, such as computer 110 .
As mentioned above, packet sniffer 100 receives RF packets from ad-hoc network 120 . After some processing via microprocessor 210 , data from the received packets are loaded into FIFO packets deposited into memory 220 . This information is then transferred to communications interface 230 for communication to computer 110 .
Communications interface 230 removes the information from memory 220 before transmitting it to the interfaced device, such as computer 110 . Communications interface 230 may include, for example, an RS-232 serial channel device, but other communications interfaces are possible, such as RS-485, USE, PCMCIA, infrared, Ethernet and the like. Communications interface 230 transmits the information obtained from memory 220 to computer 110 , such as PC 110 . Software tools running on PC 110 use the information transmitted by packet sniffer 100 to create a variety of graphical, table, etc. and presentations of the surrounding RF ad-hoc network 120 . These tools significantly simplify the installation, maintenance and troubleshooting of ad-hoc network 120 .
Referring now to FIG. 3 there is seen an exemplary flow process 300 describing the functionality of packet sniffer 100 . The process 300 begins at start step 310 and proceeds to step 320 where it is checked whether an RF packet has been received from ad-hoc network 120 . If a packet is not detected and received, process 300 proceeds to end step 370 . If decision step 320 detects an RF packet from ad-hoc network 120 , process 300 proceeds to decision step 330 where it is determined whether the received RF packet is an “E” type packet or “E-Packet”—i.e., a packet containing status information of a network node of ad-hoc network 120 . If the RF packet is not an E-packet, process 300 proceeds to step 350 where a FIFO packet is created in accordance with at least one field contained in the received RF packet, such as a packet type field, source ID field and/or data field. Sniffer 100 may also include within the FIFO packet information such as the radio signal strength of the received packet, the identifier of a node in ad-hoc network 120 to receive the packet, the identifier of the transmitting device or node, and the hierarchal level of the transmitting device or node. After the FIFO packet is created by step 350 , process 300 proceeds to step 360 , at which a FIFO buffer is loaded for transmission of the FIFO packets through communications interface 230 to a connected device, such as computer 110 . Process 300 then ends at end step 370 .
If it is determined in step 330 that the received RF packet is an E-Packet, process 300 proceeds to step 340 where sniffer 100 creates a FIFO packet. The FIFO packet created at step 340 may be (but need not be) similar to the one created at step 350 , but may also include additional information, such as status information of a network node of ad-hoc network 120 that transmitted the E-packet to sniffer 100 . This information may include, for example, an Received Signal Strength Indicator (“RSSI”) measured for the received packet, the identification of the device or node of ad-hoc network 120 to receive the packet, the hierarchal level of the device or node of the ad-hoc network 120 that transmitted the E-packet, and/or the identification of the device or node of ad-hoc network 120 transmitting the E-packet.
Referring now to FIG. 4 , there is seen a flow process 400 for transmitting FIFO packets from the FIFO buffer of sniffer 100 to a connected computer 110 via communications interface 230 . Flow process 400 may (but need not) follow completion of process 300 shown in FIG. 3 .
Process 400 begins at start step 410 and proceeds to decision step 420 where it is determined whether a serial transmission port of sniffer 100 is in a transmit mode, i.e., whether it is in the process of transmitting a FIFO packet to a connected computer 110 via communications interface 230 . If so, it is checked in step 460 whether the serial port is done transmitting the FIFO packet. If not, the serial port is allowed to continue transmitting the packet in step 480 and process 400 ends at end step 490 . If it is determined in step 460 that the serial port is done transmitting the FIFO packet, the serial port is taken out of transmit mode in step 470 and process 400 ends at end step 490 .
If it is determined in step 420 that the serial transmission port is not in a transmit mode, then it is checked in step 430 whether the FIFO buffer is empty. If so, process 400 proceeds to end step 490 and process 400 ends. If the FIFO buffer is not empty, the process proceeds to step 440 where a FIFO packet is loaded into the FIFO buffer. Then, process 400 proceeds to step 450 where the serial port is placed into transmit mode and transmission of the FIFO packet begins. Process 400 then proceeds to end step 490 .
After end step 490 , sniffer may begin process 300 once again, and both process 300 and 400 may be executed consecutively in an endless loop. | A sniffer for an ad-hoc network including an RF transceiver for receiving network packets from the ad-hoc network, the RF transceiver being operable to receive the network packets without the sniffer being connected to the ad-hoc network; a microprocessor connected to the RF transceiver for processing the network packets to create associated FIFO packets; a memory connected to the microprocessor for storing the associated FIFO packets, and a communications interface for receiving the associated FIFO packets from the memory and for transmitting the associated FIFO packets to a computer. | 7 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a plate-link chain having a plurality of link plates that are hingedly connected with each other by pairs of rocker members.
2. Description of the Related Art
Plate-link chains generally include rocker member pairs that are composed of two rocker members each, wherein the rocker members extend transversely to the longitudinal direction of the plate-link chain. The rocker member pairs are positioned within openings in the link plates and with some degree of play therebetween. Curved contact surfaces are provided on the rocker members and on the link plates, along which curved surfaces the rocker members and link plates bear against each other to transmit force. The rocker members include curved rolling surfaces along which the rocker members of a rocker member pair roll against each other and/or slide on each other to transmit force.
Such a plate-link chain can be used as a means of transmitting traction force in a belt-driven conical-pulley transmission, or as a toothed plate-link chain in a toothed belt-driven transmission, in motor vehicles or the like, for example. In a plate-link chain the tractive force is transferred by means of frictional contact between outer ends of the rocker members and the conical disk surfaces of the two conical pulleys. In the case of a toothed plate-link chain the tractive force is transferred through meshing of the teeth of the toothed plate-link chain with teeth of the toothed wheels.
In the region of the plate-link chain or toothed plate-link chain that is not encircling the conical pulleys or toothed wheels, i.e., in the region in which the plate-link chain is running freely, the chain can vibrate laterally. That involves transverse vibrations of the chain in the direction of the axes of rotation of the conical pulleys or toothed wheels. Furthermore, vibrations of the plate-link chain or toothed plate-link chain are possible in the direction of force transfer and again perpendicular to the direction of force transfer as so-called strand vibrations.
In particular, lateral vibrations of the plate-link chain or toothed plate-link chain increase the necessary structural space for the housing of a transmission, because striking of the chain against the housing wall should be avoided.
An object of the present invention is therefore to provide a plate-link chain or a toothed plate-link chain that has a small vibration amplitude, in particular in the case of lateral vibrations. In addition, the invention relates to the use of such a plate-link chain in a belt-driven transmission.
SUMMARY OF THE INVENTION
The object is achieved by a plate-link chain having a plurality of link plates hingedly connected with each other by pairs of rocker members that include two rocker members each. The rocker members extend transversely to the longitudinal direction of the plate-link chain and are positioned with some degree of play in openings in the link plates. Curved contact surfaces are provided on the rocker members and on the link plates, along which curved surfaces the rocker members and link plates bear against each other to transmit force. The rocker members include curved rolling surfaces along which the rocker members roll against each other and/or slide on each other to transmit force.
The play between the rocker members and the opening in an adjacent link plate is less than 0.2 mm. A play of from about 0.05 mm to about 0.15 mm has proven to be especially advantageous. As hereafter used herein, the term plate-link chain includes a toothed plate-link chain. In addition, it has proven to be especially advantageous if the link plates have a thickness in a direction transverse to the longitudinal direction of the plate-link chain, and that the play is one fiftieth ( 1/50) to one fifteenth ( 1/15) of the thickness of the link plate. It has been found that due to the play of from about 0.05 mm to about 0.15 mm, or with a play S that is approximately one fiftieth ( 1/50) to one fifteenth ( 1/15) of the thickness of the link plates, a distinct reduction of the tendency of the plate-link chain to vibrate laterally results.
A refinement of the plate-link chain in accordance with the invention provides that the openings have play reduction points that limit the play locally to from about 0.05 mm to about 0.15 mm, and/or to one fiftieth ( 1/50) to one fifteenth ( 1/15) of the thickness of the link plates. Instead of limiting the play across the entire contour of the openings or rocker members, the desired effect can be achieved through individual selected locations at which there is less play.
In a further preferred embodiment of the plate-link chain in accordance with the present invention there is provided a perpendicularity tolerance of the inner surface of the openings that is smaller than 0.02 mm. In another preferred embodiment of the plate-link chain in accordance with the present invention, it is provided that the openings have at least three regions that are curved convexly inward. The convexly-inwardly-curved regions limit the ability of the rocker members to twist relative to the link plates. Preferably, the rocker members are asymmetrically formed in a cross section running in the longitudinal direction of the plate-link chain in the direction of the rocker member height. The asymmetrical design results in a more favorable introduction of the pressure forces in the region of the contact surfaces between the rocker members and the link plates.
The object identified earlier is also achieved by the use of a plate-link chain in accordance with the invention in a belt-driven transmission, in particular as a plate-link chain in a belt-driven conical-pulley transmission with a continuously variable transmission ratio, or as a toothed plate-link chain in a toothed wheel transmission.
BRIEF DESCRIPTION OF THE DRAWINGS
The structure, operation, and advantages of the present invention will become further apparent upon consideration of the following description, taken in conjunction with the accompanying drawings in which:
FIG. 1 is a side view of a toothed plate in accordance with the existing art;
FIG. 2 is a portion of a further tooth plate in accordance with the existing art;
FIG. 3 a is an illustration of the play of a rocker member pair in openings of the link plates of a toothed plate-link chain in accordance with the existing art;
FIG. 3 b is an illustration of the play of a rocker member pair in openings of the link plates of a toothed plate-link chain in accordance with an embodiment of the present invention;
FIG. 4 is a longitudinal cross section through a plate-link chain in accordance with the present invention in a top view;
FIG. 5 is a section through a plate-link chain in accordance with the invention corresponding to the view of the plate-link chain in FIG. 4 ;
FIG. 6 is an enlarged, fragmentary top view of a link plate of FIG. 5 ;
FIG. 7 is a schematic top view of a belt-driven transmission having a toothed plate-link chain in accordance with the present invention or a toothed plate-link chain in accordance with the existing art to illustrate the lateral vibrations of the chain.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 shows link plates 1 and 1 ′, which are designed as toothed plates, as a detail of a toothed plate-link chain 22 that is otherwise not shown. In the case of a toothed plate-link chain the link plates 1 and 1 ′ are provided with two teeth 2 and 2 ′; in a plate-link chain the teeth 2 and 2 ′ are omitted. Plate-link chain 22 is formed in a known manner by the alternating overlapping arrangement of link plates 1 and 1 ′, whereby the link plates 1 , 1 ′ forming part of adjacent chain links are hingedly connected to each other by rocker member pairs 3 . The rocker member pairs 3 each include a first rocker member 4 and a second rocker member 4 ′, which roll against each other on respective rolling surfaces 23 when plate-link chain 22 bends as it passes around a pulley. Each rocker member pair 3 is received in a receiving opening 7 of link plate 1 ; the receiving opening 7 includes a contact surface 6 .
In the representation in FIG. 1 , rocker member 4 bears against the contact surface 6 of link plate 1 , while rocker member 4 ′ bears against the contact surface 6 ′ of the adjacent link plate 1 ′. Rocker member 4 has a curved contact surface that bears against the contact surface 6 of receiving opening 7 of link plate 1 . Rocker member 4 ′ has a corresponding curved contact surface 5 ′ that bears against the contact surface 6 ′ of a receiving opening in link plate 1 ′, which is laterally adjacent to link plate 1 . The surface 8 of receiving opening 7 located opposite the contact surface 6 is designed so that a gap 24 is formed between the curved surface 5 ′ of rocker member 4 ′, which bears against a receiving opening in the adjacent link plate 1 ′, and surface 8 of receiving opening 7 . Thus, rocker member 4 ′ does not touch the surface 8 of receiving opening 7 of link plate 1 . A corresponding gap also exists between rocker member 4 and the surface of a corresponding receiving opening in link plate 1 ′.
FIG. 2 shows a detail of a further known link plate 1 . The adjacent link plate 1 ′ is not shown, and only the left part of the link plate 1 corresponding to the representation in FIG. 1 , and associated with tooth 2 , is shown. Receiving opening 8 ′ has three convexly curved lobes A, B, and C that extend inwardly into receiving opening 8 ′. Rocker member 4 of rocker member pair 3 has a concave contraction AW which is associated with and is opposite to lobe A, while rocker member 4 ′ has a contraction BW that is associated with and is opposite to lobe B. Contraction AW bears against lobe A when the chain bends. Correspondingly, the contraction BW of rocker member 4 ′ bears against lobe B when the plate-link chain bends, and thus excessive twisting of the rocker members 4 and 4 ′ against each other is prevented, in particular if the plate-link chain swings back.
The lobe C, situated toward the upper surface of the chain, when viewed in the running direction, serves to secure the rocker members 4 and 4 ′ against twisting when the plate-link chain bends. A dashed circle 9 in FIGS. 1 and 2 clearly shows a region with a relatively large spacing between the surface of rocker member 4 ′ and the surface of receiving opening 8 ′ of link plate 1 . In the embodiment of the plate-link chain in accordance with FIG. 2 , possible motion in the direction of double headed arrow R of the rocker member 4 ′ relative to rocker member 4 is determined by the distance ax between the surface of rocker member 4 ′ and the surface of receiving opening 8 ′ of link plate 1 .
FIG. 3 a shows a side view of two known link plates 1 and 1 ′ corresponding to the representation in FIG. 1 , to clearly show the play between the rocker members and the two link plates 1 and 1 ′. A play value designated as S between the rocker members and the link plates 1 and 1 ′ is caused by the loose reception of the rocker member pair 3 in the receiving opening 7 of link plate 1 and the receiving opening 7 ′ of link plate 1 ′. Link plate 1 , as well as the receiving opening 7 of link plate 1 and the rocker member 4 supported in receiving opening 7 , are shown in dashed lines in FIG. 3 a . Link plate 1 ′, the associated receiving opening 7 ′ and the rocker member 4 ′ supported in the receiving opening are shown with solid lines. The link plates 1 and 1 ′ have a play value S relative to the rocker member pairs 3 . The two link plates 1 and 1 ′ can thus be moved relative to each other by the play value 2 S. For a known plate-link chain the play is about 0.2 mm, so that the total play within the entire length of the known plate-link chain adds up to several millimeters.
FIG. 3 b shows two link plates 1 and 1 ′ of a plate-link chain 22 in accordance with the present invention, wherein the play value S is reduced to a value of from about 0.05 mm to 0.15 mm. The reduction of the play from 0.2 mm in the known chains to a value of between 0.05 mm to 0.15 mm can occur locally at one place, for example at a local play reduction point 10 or 10 ′ as shown in FIG. 3 b . The local play reduction points 10 and 10 ′ are preferably situated so that they cause the play reduction only when the plate-link chain is not bent, so that in the bent state the play reduction points nevertheless do not come into contact with the rocker members 4 or 4 ′. FIG. 3 b shows the play reduction for a toothed plate-link chain corresponding to the representation of the link plate in FIG. 2 , i.e., a toothed plate-link chain in which the individual chain links are provided with lobes A, B, and C. However, the play value reduction to S=0.05 mm to 0.15 mm can also be made with a plate-link chain in accordance with FIG. 1 , i.e., a plate-link chain without lobes.
The reduction of the play value S by local play reduction points 10 and 10 ′ is accomplished in that the receiving openings 7 and 7 ′ have a zone in the region of the opening surfaces 8 or 8 ′ that reduces the play to a value of S=0.05 to 0.15 mm, in particular when the plate-link chain is not bent. In that case the play S is about one fiftieth ( 1/50) to one fifteenth ( 1/15) of the thickness b of link plate 1 . The thickness b of link plate 1 is shown in FIGS. 4 and 5 and is the thickness of the link plates measured in the transverse direction in a top view of the plate-link chain.
It has been found that because of the reduced play to a value of 0.05 mm to 0.15 mm, or with a play-value S that is approximately one fiftieth ( 1/50) to one fifteenth ( 1/15) of the thickness of the link plates, a distinct reduction of the tendency of the plate-link chain to vibrate laterally results, which vibratory mode is shown in FIG. 7 .
FIGS. 4 and 5 each show fragmentary longitudinal cross-sections through a plate-link chain in accordance with the invention in top views. The figures show stacks of portions of link plates of two adjacent chain links corresponding to the representation in FIGS. 3 a and 3 b , with one link plate 1 and two link plates 1 ′ of two adjacent chain links shown. Because of the play value S represented in FIGS. 3 a and 3 b , rocker members 4 and 4 ′ are able to carry undergo a tilting motion in the longitudinal direction of the plate-link chain. As shown in FIG. 4 , the longitudinal axis 11 of the rocker member pair 3 , or of rocker members 4 and 4 ′, then deviates from the transverse axis 12 of the plate-link chain by a tilt angle α. Transverse axis 12 is perpendicular to the chain running direction, which is shown in FIG. 4 by double headed arrow 13 . The reduction of the play value S in accordance with the present invention causes the tilt angle α to be reduced, as shown in FIG. 5 .
An additional reduction of the play value S and of the tilt angle α is achieved by the perpendicularity tolerance of the inner surfaces of the receiving openings 7 and 7 ′ of the link plates 1 having a value smaller than 0.02 mm. To illustrate the perpendicularity tolerance R, a reference surface 14 and an arrow 15 are shown in FIG. 6 . In that respect the illustrated representation corresponds to DIN ISO 1101. A tolerance axis 16 of the receiving opening 7 or 7 ′ of a link plate 1 or 1 ′ must be spaced at a distance less than 0.02 mm between two parallel planes 17 and 17 ′, which are perpendicular to reference surface 14 and to the direction of arrow 15 . For clarification this is shown in FIG. 6 in enlarged form on the basis of the chain link 1 ′ shown in FIG. 5 . The distances R 1 and R 2 from tolerance axis 16 to reference planes 17 and 17 ′ are both smaller than 0.02 mm. The distances R 1 and R 2 from axis 16 to reference surfaces 17 and 17 ′ add up to the perpendicularity tolerance R, where R 1 <R and R 2 <R.
FIG. 7 illustrates the effect of the play reduction in accordance with the present invention, and of the reduction of the perpendicularity tolerance R in accordance with the present invention. FIG. 7 shows a schematic top view of a belt-driven transmission including a first toothed wheel 18 and a second toothed wheel 19 , each of which is encircled by a toothed plate-link chain 20 . When the belt-driven transmission is in operation the plate-link chain 20 can execute lateral vibrations, the directions of which are identified by double headed arrow 21 . The lines representing the maximum excursion of chain 20 are shown as dashed lines for a known toothed plate-link chain 20 , and as solid lines for a toothed plate-link chain in accordance with the present invention. The tendency to vibrate laterally, i.e., the excursions in the directions indicated by the double headed arrow 21 , is reduced significantly by the design of the plate-link chain or toothed plate-link chain in accordance with the present invention. As a result, the plate-link chain in accordance with the present invention does not strike against a housing wall of the belt-driven transmission, so that acoustic emissions resulting from the lateral vibration of the are reduced.
Although particular embodiments of the present invention have been illustrated and described, it will be apparent to those skilled in the art that various changes and modifications can be made without departing from the spirit of the present invention. It is therefore intended to encompass within the appended claims all such changes and modifications that fall within the scope of the present invention. | A plate-link chain having a plurality of link plates hingedly connected with each other by pairs of rocker members that each include two rocker members. The rocker members extend transversely to the longitudinal direction of the plate-link chain and are situated with play in openings in the link plates. The rocker members and the link plate openings each have respective curved contact surfaces along which the rocker members and the link plates bear against each other to transmit force. The rocker members include curved rolling surfaces along which the rocker members roll against each other during chain operation to transmit force. The play value between the rocker members and the opening in an adjacent link plate is less than 0.2 mm to minimize lateral vibrations of the chain during operation, to prevent contact of the chain with an enclosing housing and thereby reduce emitted noise. | 5 |
[0001] The invention relates to a device for the stuffer box crimping of a synthetic multifilament yarn.
[0002] The disclosure in German Patent Application 101 32 148.1 of Jul. 3, 2001 and PCT/EP02/07161 of Jun. 28, 2002 are incorporated herein by reference.
BACKGROUND OF INVENTION
[0003] An example of a device for the stuffer box crimping of a multifilament yarn is disclosed in EP 0 554 642 A1. The device comprises a conveying nozzle and a stuffer box arranged downstream from the conveying nozzle. The yarn is hereby conveyed by means of the conveying nozzle into the stuffer box, compressed to a yarn plug and thereby stuffer box crimped. The conveying nozzle is loaded with a conveying medium, preferentially a hot gas, which conveys the yarn within the yarn channel to the stuffer box. The yarn plug is formed inside the stuffer box. In doing so, the multifilament yarn deposits itself in loops on the surface of the yarn plug and is compressed by the conveying medium, which can discharge above the yarn plug out of the stuffer box. To do so, the chamber wall of the stuffer box comprises several slot-shaped openings on the perimeter through which the conveying medium can escape. In order to obtain uniform crimping of the yarn, plug formation must result with very high uniformity in the stuffer box. Thus, the friction forces caused by the relative motion of the yarn plug in the stuffer box have a substantial impact on the texturizing process. A counterbalance of forces exists between the conveying effect, or the dynamic pressure effect of the conveying medium flowing from the yarn channel of the conveying nozzle, and the braking action resulting from the friction forces on the yarn plug. Adjusting the conveying pressure, or adjusting additional suction of the conveying medium, essentially determines the conveying effect. In contrast, the braking action resulting from the friction between the yarn plug and the chamber wall essentially depends on the condition of the chamber wall.
[0004] In the device disclosed in EP 0 554 642 A1, only a slight number of friction surfaces exist due to the slot-shaped openings especially in the section with the gas-permeable wall. Therefore, wear marks are unavoidable in prolonged operation, which results in a change in the braking action. If the braking action decreases sufficiently, the yarn plug will be conveyed out of the stuffer box due to small frictional forces. The texturizing process then fails. On the other hand, as frictional forces increase, the yarn plug is no longer or no longer uniformly conveyed out of the stuffer box. Non-uniform stuffer box crimping occurs when a stick-slip effect begins in the stuffer box. These effects cannot be controlled with a dynamic medium opposing the conveying medium.
[0005] In contrast, one task of the present invention is to further improve a stuffer box crimping device for synthetic multifilament yarn in such a manner that uniform crimping is ensured in the yarn, even during very prolonged operation.
SUMMARY OF INVENTION
[0006] According to this invention, the task is solved by a device for compressing a synthetic, multifilament yarn, the device including a conveying nozzle and a stuffer box. The conveying nozzle includes a yarn channel for guiding and conveying the yarn. The stuffer box is arranged at the end of the yarn channel to form and collect a yarn plug. The stuffer box includes a yarn inlet, a plug outlet, and at least a section with a gas-permeable chamber wall between the yarn inlet and the plug outlet. The gas-permeable chamber wall includes a friction surface made of wear-resistant material on an inner side facing the yarn plug.
[0007] The friction surface of the section may be a coating applied to the surface of the gas-permeable chamber wall. Alternatively, the gas-permeable chamber wall is a ceramic material that forms the friction surface on the surface of chamber wall.
[0008] The gas-permeable chamber wall may be formed as a cylindrical body with elongated slots evenly distributed along the circumference. Alternatively, the gas-permeable chamber wall may be formed by a plurality of blades arranged in a ring-shape with little separation distance from each other.
[0009] The stuffer box may include an additional section downstream from the section with the gas-permeable chamber wall. The additional section includes an enclosed chamber wall. The enclosed chamber wall includes a contact surface made of wear-resistant material on the inner side facing the yarn plug.
[0010] As with the section, the friction surface of the additional section may be a coating applied to the surface of the enclosed chamber wall. Alternatively, the enclosed chamber wall is a ceramic material that forms the friction surface on the surface of chamber wall.
[0011] Further, the contact surfaces contacted by the yarn within the conveying nozzle may be at least partially formed from a wear-resistant material. The wear-resistant material may be in the form of a coating or a ceramic material.
[0012] The conveying nozzle may include a guide insert forming an inlet of the yarn channel. The guide insert includes an intake channel arranged as an extension of the yarn channel. Also, the conveying nozzle may include a second guide insert forming the outlet of the yarn channel. As with the guide insert, the second guide insert may be manufactured from a ceramic material or coated on its surface. Further, the conveying nozzle may include a third guide insert forming the air inlet into the yarn channel. The third guide insert forms a guide channel arranged as an extension of the yarn channel. The third guide insert forms an outlet channel arranged as an extension of the yarn channel. The guide inserts may be manufactured from a ceramic material or coated on its surface.
[0013] The third guide insert may further include an insert forming the inlet of the guide channel. The insert forms an intake channel arranged as an extension of guide channel. The inserts may be manufactured from a ceramic material or coated on its surface.
[0014] Any one of a conveying device, cooling device, and a conveying device in combination with a cooling device may be arranged downstream from the stuffer box in the yarn's direction of travel. The conveying device and the cooling device may include a coating on the contact surfaces contacted by the yarn plug.
[0015] The invention is based on the knowledge that depositing of the yarn on the yarn plug surface by self-shaping loops and coils significantly influences crimp uniformity. In order to maintain the yarn's point of impact on the yarn plug surface at an essentially unchanging height, the balance of forces between the conveying effect and the brake action at the yarn plug resulting from the friction must be held constant. This can be essentially achieved by the device according to this invention in that the gas-permeable chamber wall comprises a friction surface made of wear-resistant material on the inner side facing the yarn plug. Thereby, a change in the friction forces is not possible even in extended operation. Thus, the invention has the advantage that plug formation is solely controlled by controlling the conveying medium by, for example, means of pressure control.
[0016] The wear-resistant material on the surface of the chamber wall can be constructed essentially from two variants. In an initial especially preferred embodiment of the invention, the friction surface is formed by a coating applied to the chamber wall surface. This coating could consist, for example, of a ceramic material, a chrome oxide or a carbon coating. The possibility also exists to manufacture the chamber wall from aluminum in order to then form anti-wear protection by means of a hard oxide coating.
[0017] In another especially preferred embodiment of the invention, the friction surface is formed by a chamber wall manufactured from a ceramic material. To this end, the chamber wall can be manufactured out of ceramic materials such as zircon oxide, aluminum oxide or a combination of both.
[0018] The use of ceramic coatings, or ceramic materials, also achieves a corrosion-resistant gas-permeable wall and decreased fallibility to fouling. In particular, deposits caused by preparation residue may be avoided. Even after a maintenance period, the same friction specifications are achieved when operating the device as prior to shutting down the facility.
[0019] Regardless whether a coating or solid-ceramic is used to form the friction surface, the gas-permeable chamber wall can be designed as a cylindrical body with evenly distributed elongated slots along its circumference.
[0020] However, an especially preferred embodiment has a gas-permeable chamber wall with a plurality of blades that are arranged in a ring-shape with clearance from each other. Thus, it was observed in the use of ceramic blades that decreasing the friction coefficient subjects the yarn to less of a thermal and mechanical load.
[0021] In order to avoid wear inside the stuffer box on all sides contacting the yarn plug, an additional section with an enclosed chamber wall may be provided. In accordance with a preferred embodiment of this invention, the stuffer box includes an additional section with an enclosed chamber wall. The additional section is downstream from the section with the gas-permeable chamber wall. The enclosed chamber wall includes a contact surface comprised of a wear-resistant material on the inner side facing the yarn plug.
[0022] The contact surface could be formed by a coating applied to the surface of the chamber wall or by a chamber wall manufactured from ceramic material.
[0023] It was observed that when using a conveying nozzle with ceramic sides at least on parts of the surface contacting the yarn, that the yarn tension reduction in the conveying nozzle was reduced by the friction of the yarn on the side. In accordance with a preferred embodiment, the contact surfaces contacted by the yarn within the conveying nozzle are at least partially formed from a wear-resistant material in the form of a coating or a ceramic material. Thus, higher yarn tension can be achieved with the same conveying pressure, which results in higher operational uniformity of the texturizing process. On the other hand, yarn tension can be achieved with a lower pressure, whereby a lower conveying pressure results in less consumption of the conveying medium. The contact surface's wear-resistant material inside the conveying nozzle can be formed of coatings or ceramic base materials. Thus, the conveying nozzle can be preferentially manufactured entirely out of ceramics.
[0024] In another embodiment variant of the invention, the inlet of the yarn channel is formed by means of a guide insert in the conveying nozzle. The guide insert, which can be manufactured from a ceramic material or carry a coating on its surface, forms an intake channel as an extension of the yarn channel. Wear, in particular, at the yarn's entry into the conveying nozzle is thereby avoided. Using ceramic materials or ceramic coatings also enables a very low friction guidance of the yarn.
[0025] The conveying nozzle could also comprise a guide insert forming the yarn channel's outlet, which is also manufactured from a ceramic material or carries a coating on its surface. The yarn thereby leaves the conveying nozzle through the guide insert's outlet channel.
[0026] To convey the yarn, a conveying medium, preferentially hot air or a hot gas, is supplied. In order not to have any scouring in the yarn channel even at very high flow speeds, that may even lie in the range of the speed of sound, the air inlet into the yarn channel is formed by means of a guide insert, according to a preferred embodiment of the invention. Next to the air inlet, the guide insert comprises a guide channel that is arranged as an extension of the yarn channel. The guide insert is also made of a ceramic material or carries a coating on its surface.
[0027] Since the conveying medium flowing into the yarn channel results in a sudden dynamic load for the yarn, in a preferred embodiment of the invention, the third guide insert includes an additional insert forming the inlet of the guide channel. The additional insert forms an intake channel arranged as an extension of the guide channel. Also, the additional insert is either manufactured from a ceramic material or coated on its surface. The third guide insert in the area of the air inlet includes the additional insert in the inlet of the guide channel. In this manner, yarn guidance is stabilized and disturbances affecting the yarn are avoided.
[0028] To guide and condition the yarn plug, a cooling device is arranged downstream from the stuffer box at the plug outlet. In some cases a conveying device is provided between the cooling device and the stuffer box to guide the yarn plug. In order to avoid premature fouling and adhesion of preparation residue, in a preferred embodiment according to the present invention, the conveying device and the cooling device comprise a coating on the contact surfaces contacted by the yarn plug.
[0029] The invention is further described by means of several embodiments depicted in the attached illustrations.
BRIEF DESCRIPTION OF DRAWINGS
[0030] [0030]FIG. 1 schematically depicts an initial embodiment of the device in accordance with this invention in a cross-sectional view;
[0031] [0031]FIG. 2 schematically depicts an additional embodiment of the device in accordance with this invention in a sectional cross-section;
[0032] [0032]FIG. 3. 1 schematically depicts an embodiment of a conveying nozzle in a cross-sectional, exploded view; and
[0033] [0033]FIG. 3. 1 schematically depicts an embodiment of a conveying nozzle in a cross-sectional view.
DETAILED DESCRIPTION
[0034] [0034]FIG. 1 schematically depicts a cross-sectional view of an initial embodiment of the device in accordance with this invention. The device consists of conveying nozzle 1 and stuffer box 2 arranged downstream from conveying nozzle 1 . Conveying nozzle 1 comprises yarn channel 3 that forms inlet 21 on one end and outlet 24 on the opposite end. Conveying nozzle 1 is connected to a pressure source (not depicted) by means of feed line 17 . Feed line 17 is connected to yarn channel 3 by air inlet 16 and pressure chamber 39 . Air inlet 16 is formed by several boreholes that supply a conveying medium in yarn travel direction, marked by an arrow, to yarn channel 3 . Yarn channel 3 merges into yarn channel 31 of stuffer box 2 by means of outlet 24 .
[0035] Stuffer box 2 is formed by section 7 . 1 facing conveying nozzle 1 having yarn inlet 5 , and section 7 . 2 , arranged downstream from section 7 . 1 , having a plug outlet 6 . In section 7 . 1 , plug channel 31 is formed by a gas-permeable chamber wall 8 . Gas-permeable chamber wall 8 comprises a multiplicity of blades 9 that are arranged in a ring in close proximity to each other. Blades 9 are held by blade holders 10 . 1 on the upper end of section 7 . 1 and by holder 10 . 2 on the lower end of section 7 . 1 . Blades 9 and holders 10 . 1 and 10 . 2 are arranged in housing 11 , whereby housing 11 is enclosed to the outside and connected to suction 12 by opening 32 .
[0036] On the side facing yarn plug 13 , blades 9 each comprise friction surface 14 . Blades 9 are made of a ceramic material so that friction surfaces 14 consist of a wear-resistant material.
[0037] Enclosed chamber wall 15 is provided below the gas-permeable chamber wall 8 , which forms plug channel 33 . Plug channel 33 is designed to have a larger diameter than the plug channel 31 in the area of the gas-permeable chamber wall 8 . At its end, plug channel 33 forms plug outlet 6 .
[0038] The embodiment of the device in accordance with this invention and depicted in FIG. 1 is shown with a yarn course in order to clarify the device's function. Thus, yarn 4 is transported through conveying nozzle 1 into yarn channel 3 by means of a conveying medium supplied via air inlet 16 . Yarn 4 thereby enters into yarn channel 3 through inlet 21 . Hot air or a hot gas are preferentially used as conveying medium. The conveying medium flowing at high speed conveys yarn 4 at high speed to stuffer box 2 . In doing so, yarn plug 13 develops in plug channel 31 . Yarn 4 , comprised of a plurality of filaments, is deposited on the surface of yarn plug 13 in such a manner that the filaments form loops and coils. The conveying medium is suctioned off between and past blades 9 through opening 32 . Yarn plug 13 forming in plug channel 31 abuts on friction surfaces 14 of blades 9 . The friction forces and the conveying pressure of the conveying medium acting on yarn plug 13 are essentially counterbalanced so that the yarn plug height within the yarn channel 31 remains essentially the same. Since blades 9 are manufactured from a ceramic material, the counterbalancing forces acting on yarn plug 13 are essentially maintained by constant pressure of the conveying medium. After leaving plug channel 31 , yarn plug 13 enters into plug channel 33 that is formed by enclosed chamber wall 15 . Enclosed chamber wall 15 that could be constructed from a tube, for example, serves to feed yarn plug 13 to a downstream placed cooling device not depicted here. Plug channel 33 is designed larger than plug channel 31 so that only slight friction forces act on yarn plug 13 . Anti-wear protection is therefore unnecessary.
[0039] [0039]FIG. 2 schematically depicts an additional embodiment in a cross-sectional view. The embodiment is essentially identical in its design to the previous embodiment according to FIG. 1, so that hereafter only the essential differences will be pointed out. For clarity's sake, components having identical functions are identically labeled.
[0040] For additional acceleration of the conveying medium in yarn channel 3 , conveying nozzle 1 comprises its smallest diameter directly downstream from air inlet 16 . The conveying medium is thereby accelerated to a supersonic flow velocity. Yarn channel 3 merges into plug channel 32 that is formed by cylindrical body 18 . Cylindrical body 18 is arranged in the first section 7 . 1 of stuffer box 2 . Cylindrical body 18 has distributed on its circumference several elongated slots 34 , whereby plug channel 31 is connected to annulus 35 formed by housing 11 and cylindrical body 18 . On annulus 35 and above opening 32 , housing 11 is connected to suction 12 . On the side facing yarn plug 13 , cylindrical body 18 has coating 19 . Coating 19 , forming friction surface 14 to guide a yarn plug, consists preferentially of a ceramic material. However, metallic hard chrome layers or carbon compounds are also possible. Thus, cylindrical body 18 may also be manufactured from an aluminum material, which receives an aluminum oxide coating forming friction surface 14 . Elongated slots 34 extend at least over a portion of cylindrical body 18 .
[0041] The second section 7 . 2 of the stuffer box is formed by enclosed chamber wall 15 that comprises plug channel 33 . Plug channel 33 forms at its end plug outlet 6 . On the side facing yarn plug 13 , enclosed chamber wall 15 comprises contact surface 20 that also carries wear-resistant coating 35 .
[0042] Formed out of two opposing rollers, conveying device 29 is attached directly to stuffer box 2 at plug outlet 6 . Conveying device 29 guides the yarn plug 13 to a cooling device 30 arranged downstream from conveying device 29 . Cooling device 30 could be constructed from a cooling barrel on whose circumference the yarn plug is cooled. Both conveying device 29 and cooling device 30 are furnished with a coating on their contact surfaces 37 and 38 .
[0043] The function of the embodiment depicted in FIG. 2 is essentially identical to the previous embodiment according to FIG. 1, so that depicting the yarn course was not repeated. However, yarn plug development can be also influenced by conveying device 29 .
[0044] [0044]FIGS. 3. 1 and 3 . 2 schematically depict an embodiment of a conveying nozzle in a cross-sectional view as it might be used for example in the embodiment according to FIG. 1 or the embodiment according to FIG. 2. The conveying nozzle is thus depicted in FIG. 3. 1 in a disassembled state and in FIG. 3. 2 in an assembled state. The following description applies for both illustrations, unless express reference is made to one of the illustrations.
[0045] Conveying nozzle 1 comprises in the areas of inlet 21 , air inlet 16 , outlet 24 , and grooves 36 . 1 , 36 . 2 , and 36 . 3 respectively.
[0046] Grooves 36 . 1 , 36 . 2 , and 36 . 3 are connected to each other by means of yarn channel 3 . Pressure chamber 39 is designed in conveying nozzle 1 between grooves 36 . 1 and 36 . 2 . Groove 36 . 1 in the intake section of conveying nozzle 1 serves to receive guide insert 22 . 1 . Guide insert 22 . 1 forms an intake channel 23 that is arranged as an extension of yarn channel 3 . Guide insert 22 . 1 is preferentially manufactured from ceramic material. However, it is also possible that guide insert 22 . 1 carries a coating in the area of the intake channel 23 .
[0047] Guide insert 22 . 1 is inserted into groove 36 . 2 . Guide insert 22 . 2 forms air inlet 16 through which the conveying medium is fed from pressure chamber 39 into guide channel 26 of guide insert 22 . 2 . Guide channel 26 of guide insert 22 . 2 is arranged as an extension of yarn channel 3 . Insert 27 , which forms intake channel 28 , is provided on the inlet side of guide insert 22 . 2 . Intake channel 28 has a smaller diameter than guide channel 26 located downstream. Insert 27 and guide insert 22 . 2 may also be preferentially manufactured from a ceramic material or furnished with a coating.
[0048] Guide insert 22 . 3 is embedded in groove 36 . 3 on the outlet side of conveying nozzle 1 . Guide insert 22 . 3 forms outlet channel 25 that is arranged as an extension of yarn channel 3 and forms outlet 24 of conveying nozzle 1 . Guide insert 22 . 3 is also preferentially manufactured from a ceramic material.
[0049] The conveying nozzle depicted in FIGS. 3. 3 and 3 . 2 consists of a wear-resistant material especially in the contact and friction areas heavily stressed by the yarn so that stable and uniform yarn guidance as well as yarn conveying are achieved. In addition, the friction coefficients between the yarn and the contact or friction points are substantially decreased.
[0050] In the device depicted in FIGS. 1 to 3 , one should note that conveying nozzle 1 and stuffer box 2 are each preferentially formed out of two halves that are frictionally connected with each other during operation. However, it is also possible to basically provide one-piece conveying nozzles and stuffer boxes with corresponding ceramic inserts or coatings. Regardless of the device's design type, the possibility also exists, however, to manufacture each of the devices' yarn-contacting areas from solid ceramics or a coated aluminum material. The device according to this invention thereby distinguishes itself especially by a high degree of wear-protection and thus stable friction behavior and non-sensitivity to yarn conditioning, as well as a substantial lengthening of the cleaning cycles due to the resistance to fouling. Using a device in accordance with this invention, the service life was increased 3- to 5-fold. When using the device in accordance with this invention, which was furnished with ceramic materials or ceramic material coatings, crimping of the yarn could be kept uniform over a substantially longer period than compared to conventional crimping devices. A significantly higher degree of production safety is thereby achieved.
Reference List
[0051] [0051] 1 Conveying nozzle
[0052] [0052] 2 Stuffer box
[0053] [0053] 3 Yarn channel
[0054] [0054] 4 Yarn
[0055] [0055] 5 Yarn inlet
[0056] [0056] 6 Plug outlet
[0057] [0057] 7 Section
[0058] [0058] 8 Gas-permeable chamber wall
[0059] [0059] 9 Blade
[0060] [0060] 10 Blade holder
[0061] [0061] 11 Housing
[0062] [0062] 12 Suction
[0063] [0063] 13 Yarn plug
[0064] [0064] 14 Friction surface
[0065] [0065] 15 Enclosed chamber wall
[0066] [0066] 16 Air inlet
[0067] [0067] 17 Feed line
[0068] [0068] 18 Cylindrical body
[0069] [0069] 19 Coating
[0070] [0070] 20 Contact surface
[0071] [0071] 21 Inlet
[0072] [0072] 22 Guide insert
[0073] [0073] 23 Intake channel
[0074] [0074] 24 Outlet
[0075] [0075] 25 Outlet channel
[0076] [0076] 26 Guide channel
[0077] [0077] 27 Insert
[0078] [0078] 28 Intake channel
[0079] [0079] 29 Conveyance device
[0080] [0080] 30 Cooling device
[0081] [0081] 31 Plug channel
[0082] [0082] 32 Opening
[0083] [0083] 33 Plug channel
[0084] [0084] 34 Elongated slot
[0085] [0085] 35 Annulus
[0086] [0086] 36 Groove
[0087] [0087] 37 Contact surface
[0088] [0088] 38 Contact surface
[0089] [0089] 39 Pressure chamber
[0090] The disclosure in German Patent Application 101 32 148.1 of Jul. 3, 2001 and PCT/EP02/07161 of Jun. 28, 2002 are incorporated herein by reference. The German Patent Application and the PCT Application describe the invention described hereinabove and claimed in the claims appended hereinbelow and provided the basis for a claim of priority for the instant application.
[0091] While the invention has been illustrated and described as an embodiment of a device for compression crimping, it is not intended to be limited to the details shown, since various modifications and changes may be made without departing in any way from the spirit of the present invention.
[0092] Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can, by applying current knowledge, readily adapt it for various applications without omitting features that, from the standpoint of prior art, fairly constitute essential characteristics of the generic or specific aspects of this invention. | The invention relates to a device for the compression crimping of a synthetic multifilament yarn, said device comprising a transport nozzle and a compression chamber. Said transport nozzle comprises a yarn channel by which means a yarn is guided to a compression chamber. Said compression chamber forms a section having a gas-permeable chamber wall, between a yarn inlet and an enmeshment outlet. According to the invention, the gas-permeable chamber wall comprises a friction surface consisting of material which is resistant to wear, on the inner side facing the yarn enmeshment. The constancy of the braking action produced by the friction on the yarn enmeshment can thus be significantly improved. | 3 |
BACKGROUND OF THE INVENTION
[0001] The invention relates to a method as recited in the preamble of claim 1. Storing digital audio on unitary media such as disc or tape is widespread. In case of actual sub-division of the audio into multiple sub-items, providing a Table-of-Contents (TOC) allows to access the information in an easy manner. Such TOC will specify at least what has been stored and where it has been stored. The audio may be defined according to various standardized audio formats, such as two-channel stereo, multiple (5-6) channel audio such as in surround sound applications, and possibly others. An audio provider may wish to combine various track areas having the same and/or different such formats on a single medium such as an optical disc.
SUMMARY TO THE INVENTION
[0002] In consequence, amongst other things, it is an object of the present invention to allow an audio management system to allow a user to access various audio track areas in a fast and easy manner. Now Therefore, according to one of its aspects the invention is characterized according to the characterizing part of claim 1. A user is now able to distinguish between various track areas and to navigate among the various items of a single track area in a robust manner, and if possible, without encumbrance through data users in the TOC itself.
[0003] The invention also relates to a unitary storage medium produced by the method, to a storing device arranged for practising such method, and to a reader or player device arranged for interfacing to such storage medium. A particular audio medium instance could be restricted to storing only stereo, so that the multi-channel version would effectively be a dummy. For reasons of standardizing, the multilevel TOC mechanism will then also be adopted. Further advantageous aspects of the invention are recited in dependent claims.
BRIEF DESCRIPTION OF THE DRAWING
[0004] These and further aspects and advantages of the invention will be discussed more in detail hereinafter with reference to the disclosure of preferred embodiments, and in particular with reference to the appended Figures that show:
[0005] [0005]FIGS. 1 a, 1 b a record carrier,
[0006] [0006]FIG. 2 a playback device,
[0007] [0007]FIG. 3 a recording device,
[0008] [0008]FIG. 4 a file system for use with the invention;
[0009] [0009]FIG. 5 a storage arrangement for the invention;
[0010] [0010]FIG. 6 a structure of an audio area.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0011] [0011]FIG. 1 a shows a disc-shaped record carrier 11 with track 19 and central hole 10 . Track 19 has a spiral pattern of turns forming substantially parallel tracks on an information layer. The carrier may be an optical disc with a recordable or prerecorded information layer. CD-R, CD-RW and DVD-RAM are recordable discs. Audio CD is a prerecorded disc. Prerecorded discs may be manufactured by first recording a master disc and then pressing consumer discs. Track 19 on a recordable record carrier may be formed by a preembossed track structure. The track may be configured as pregroove 14 to allow a read/write head to follow the track 19 during scanning. The information is recorded on the information layer by optically detectable marks along the track, e.g. pits and lands.
[0012] [0012]FIG. 1 b is a cross-section along the line b-b of a recordable record carrier 11 , wherein transparent substrate 15 caries recording layer 16 and protective layer 17 . Pregroove 14 may be implemented as an indentation, an elevation, or as a material property deviating from its surroundings.
[0013] For user convenience, the audio information on the record carrier is subdivided into items, which may have a duration of a few minutes e.g. songs in an album or movements of a symphony. The carrier will also contain access information to identify the items, such as a Table Of Contents (TOC) or a file system like ISO 9660 for CD-ROM. The access information may include playing time and start address for each item, and further information like a song title.
[0014] The audio information is recorded in digital representation after analog to digital (A/D) conversion. Examples of A/D conversion are PCM 16-bit per sample at 44.1 kdz known from CD audio and 1 bit Sigma Delta modulation at a high oversampling rate e.g. 64×Fs called Bitstream. The latter is a high quality encoding method, allowing either high quality decoding or low quality decoding. Reference is had to the publications ‘A digital decimating filter for analog-to-digital conversion of hi-fi audio signals’, by J. J. van der Kam, document D5 infra, and ‘A higher order topology for interpolative modulators for oversampling A/D converters’, by Kirk C. H. Chao et al, document D6. After A/D conversion, digital audio may be compressed to variable bitrate audio data for recording on the information layer. The compressed audio data is read from the carrier at such speed that after decompression substantially the original timescale will be restored when continuously reproducing the audio. Hence the compressed data must be retrieved from the record carter at a speed dependent on the varying bitrate. The data is retrieved at so-called transfer speed, i e. the speed of transferring data bytes from the record carrier to a decompressor. Providing the record carrier with constant spatial data density gives the highest data storage capacity per unit of area. The transfer speed is proportional to the relative linear speed between the medium and the read/write head. With buffer before the de-compressor, actual transfer speed is the speed before that buffer.
[0015] [0015]FIG. 2 shows a playback apparatus according to the invention for reading a record carrier 11 of the type shown in FIG. 1. The device has drive means 21 for rotating carrier 11 and read head 22 for scanning the record track, Positioning means effect 25 coarse radial positioning of read head 22 . The read head comprises a known optical system with a radiation source for generating beam 24 that is guided through optical elements and focused to spot 23 on an information track. The read head further comprises a focusing actuator for moving the focus of the radiation 24 along the optical axis of the beam and a tracking actuator for fine positioning of spot 23 in a radial direction on the centre of the track. The tracking actuator may comprise coils for moving an optical element or may be arranged for changing the angle of a reflecting element. The radiation reflected by the information layer is detected by a known detector in the read head 22 , e.g. a four-quadrant diode, to generate a read signal and further detector signals including tracking error and focusing error signals for the tracking and focusing actuators, respectively. The read signal is processed by standard reading means 27 to retrieve the data, for example through a channel decoder and an error corrector. The retrieved data is sent to data selection means 28 , to select the compressed audio data for feeding to buffer 29 , The selection is based on data type indicators also present on the carrier, e.g. headers in a framed format. From buffer 29 , the compressed audio data go to de-compressor 31 as signal 30 . Decompressor 31 decodes the compressed audio data to reproduce the original audio information on output 32 . The de-compressor may be fitted in a stand-alone audio D/A convertor 33 , or the buffer may be positioned before the data selection. Buffer 29 may reside separately or may be combined with a buffer in the decompressor. The device furthermore has a control unit 20 for receiving control commands from a user or from a host computer not shown, that via control lines 26 is connected to drive means 21 , positioning means 25 , reading means 27 and data selection means 28 , and possibly also to buffer 29 for filling level control. To tis end, the control unit 20 may comprise digital control circuitry, for performing the procedures described below.
[0016] The art of audio compression and decompression is known. Audio may be compressed after digitizing by analyzing the correlation in the signal. and producing parameters for fragments of a specified size. During de-compression the inverse process reconstructs the original signal. If the original digitized signal is reconstructed exactly, the (de-)compression is lossless. Lossy (de) -compression will not reproduce some details of the original signal which will be substantially undetectable by the human ear or eye, Most known systems for audio and video, such as or MPEG, use lossy compression, whereas lossless compression is used for computer data. Examples of audio compression and decompression are given in D2, D3 and D4 hereinafter,
[0017] Data selection means 28 will retrieve from the read data certain control information, in particular indicating the transfer speed profile. The data selection means 28 will also discard any stuffing data, that had been added during recording according to the speed profile. When the control unit 20 is commanded to reproduce an audio item from the record carrier, positioning means 25 will position the reading head on the portion of the track containing the TOC. The starting address and the speed profile for that item will then be retrieved from the TOC via the data selection means 28 . Alternatively, the contents of the TOC may be read only once and stored in a memory when the disc is inserted in the apparatus. For reproducing an item, drive means 21 will rotate the record carrier at the speed indicated by the speed profile. The required rotation rate may be given as such in the speed profile for setting the drive means, Alternatively the speed profile may comprise a bitrate, and then the rotation rate can be calculated as follows. The radial position of the item can be calculated from the starting address, because the record carrier density parameters like track pitch and bit length, will be known to the playback device, usually from a standard. Subsequently the rotation rate can be derived from the bitrate and the radial position. To provide continuous reproduction without buffer underflow or overflow the transfer speed is coupled to the reproduction speed of the D/A converter, i.e. to the bit-rate after decompression. Thereto the apparatus may comprise a reference frequency source for controlling the decompressor and the rotation rate may be set in dependence on the reference frequency and the speed profile, The rotation rate may also be adjusted by the average filling level of the buffer 29 , e.g. lowering rotation rate when the buffer is more than 50% full on average.
[0018] [0018]FIG. 3 shows a recording device for writing information on a (re)writable record carrier 11 . During a writing operation, marks representing the information are formed on the record carrier. The marks may be in optically readable form, e.g. as areas whose reflection differs from their surroundings, by recording in materials such as dye, alloy or phase change, or in the form of areas with a direct of magnetization different from their surroundings. Writing and reading of information for recording on optical disks and usable rules for formatting, error correcting and channel coding, are well-known, e.g. from the CD system. Marks may be formed through a spot 23 generated on the recording layer via a beam 24 of electromagnetic radiation, usually from a laser diode. The recording device comprises similar basic elements as described with reference to FIG. 2, i.e. a control unit 20 , drive means 21 and positioning means 25 , but it has a distinctive write head 39 . Audio information is presented on the input of compression means 35 . Suitable compression has been described in D2, D3 and D4. The variable bitrate compressed audio on the output of compression means 35 is sent to buffer 36 . From buffer 36 the data is sent to data combination means 37 for adding stuffing data and further control data. The total data stream is sent to writing means 38 for recording. Write head 39 is coupled to the writing means 38 , which comprise for example a formatter, an error encoder and a channel modulator. The data presented to the input of writing means 38 is distributed over logical and physical sectors according to formatting and encoding rules and converted into a write signal for write head 39 . Unit 20 controls buffer 36 , data combination means 37 and writing means 38 via control lines 26 and perform the positioning procedure as described above for the reading apparatus. The recording apparatus may also have the features of a playback apparatus and a combined write/read head.
[0019] [0019]FIG. 4 shows a file system for use with the invention, for which various different options are feasible. The inventors have proposed that the storage medium should be based on a UDF file system or on an ISO 9660 file system, both of which systems are standard to a skilled art person. In the alternative case, no file system should be present at all and the relevant sector spaces should be kept empty.
[0020] In the file system, all audio will be stored in Audio Files located in SubDirectory SCD_AUDIO. As shown in FIG. 4, the hierarchy is based on ROOT file 50 that points to various subaltern files 52 , 54 , 56 . The structure of MASTER.TOC 52 , here single, will be discussed hereinafter. Further, there is a 2_CH_AUDIO file 54 , This points to TOC 2_CH_TOC 58 and also to the various stereo tracks TRACKn.2CH 60 , Furthermore, M_CH_AUDIO file 56 points to TOC M_CH_TOC 62 and in parallel therewith to the various multi-channel tracks TRACKn.MCH 64 .
[0021] [0021]FIG. 5 shows a first storage arrangement for use with the invention, which by way of example has been mapped on a single serial track. Along the horizontal axis the following items are evident. Item 120 is a Lead-in area that is used for mutually synchronizing the reader and the driving of de medium. Item 122 represents the File System disclosed with reference to FIG. 4. Item 124 represents a MASTER_TOC that may be configured according to standard procedures and pertains to subsequent items Stereo AREA 126 and Multi-channel AREA 128 , and if necessary also to Extra Data AREA 130 . The lengths of these three areas need not be standardized, inasmuch as various different amounts of information may be present. With respect to the audio areas, the audio track areas proper, as well as the associated SUB 13 TOCs are included. Apart from the disclosure hereinafter, the contents of items 126 , 128 , 130 may be defined according to conventional standards that by themselves do not constitute part of the invention. Generally, the two audio areas may have the same structure and contain the same kinds of information, apart from distinguishing between the various channels. The audio may be plan coded or loss-less coded. All kinds of audio may be multiplexed with supplementary data, such as Compact Disc Text.
[0022] Item 132 represents a Lead-Out Information. The latter item is used in particular during search operations. Its tracks do not contain information further than track numbers and addresses. The number of lead-out tracks may cover a ring of some 0.5 to 1 millimeter wide. According to the above, the stored information may either be accessed via the file system as laid down in item 122 , or via the TOC structure laid down in item 124 , and more particular, via a two- or multi-level TOC structure to be discussed hereinafter.
[0023] Any of the single or plural Master TOCs 124 will begin at a respective uniformly standardized offset position from the start of the Lead-in area, such as at byte number 500 for the first Master TOC. In the embodiment a Master-TOC measures only one standard-size sector and primarily contains pointers to the various Sub-TOCs or Area-TOCs to be disclosed hereinafter. A preferred syntax of a Master-TOC is as follows:
[0024] 1. A 16-byte Signature identifies the Master-TOC, such as by “SACD Master TOC”, the signature containing three space characters, but the apostrophes not being part of the definition.
[0025] 2. A 2-byte Spec_version indicates the version number of the format used in the disc.
[0026] 3. A 14-byte Space has been reserved, such as for alignment staffing,
[0027] 4.A 4-byte integer 2CH-start_address contains the logical address of the first sector of the , stereo area.
[0028] 5. A 4-byte integer 2CH-end_address contains the logical address of the last sector of the stereo are&
[0029] 6. A 4-byte integer MC-start_address contains the logical address of the first sector of the Multi channel area
[0030] 7. A 4-byte integer MC-end_address contains the logical address of the last sector of the Multi channel area.
[0031] 8. A 4-byte integer Extra_data_start_address contains the logical address of the first sector of the Extra Data area.
[0032] 9. A 4-byte integer Extra_data_end_address contains the logical address of te last sector of the Extra Data area.
[0033] The total information pertaining to the above is 56 bytes. Further features may be added to a Master-TOC. If a certain area, such as the stereo area, the Multi channel area, or the Extra Data area is not present, both start and end addresses of the area in question have value zero.
[0034] Next, items 126 and 128 will contain Sub-TOCS or Area-Tocs for the Stereo and Multi-Channel Audio intervals, respectively, formatted as will be disclosed hereinafter with respect to FIG. 6. A preferred syntax of a Sub-TOC is as follows:
[0035] 1. A 16-byte Signature identifies the Sub-TOC in question such as by “SACD stereo TOC” for a stereo audio area and “SACD MC TOC” for a Multi Channel audio area, the number of bytes being attained by adding trailing space characters
[0036] 2. A 2-byte Spec_version indicates the version number of the format used in the disc.
[0037] 3. A 4-byte Sub_TOC_length indicates the number of bytes present in the actual TOC.
[0038] 4. A 10-byte Space has been reserved, such as for alignment stuffing.
[0039] 5. A variable size set of /* Disc Parameters */ may be present, such as a Name of an Album( ) and a Name of a Catalogue( ).
[0040] 6. A 4-byte disc_play_time indicates the total linear playing time of the disc expressed as a time code.
[0041] 7. A 4-byte disc_name_pointer indicates the offset in bytes from the start of the Sub_TOC in question to the start of the disc_name( ) field. If the value in question is 0, this indicates that the disc_name( ) field is absent.
[0042] 8. A 4-byte disc_date_pointer indicates the offset in bytes from the start of the Sub_TOC in question to the start of the disc_date( ) field. If the value in question is 0, this indicates that the disc_date( ) field is absent.
[0043] 9. A 4-byte disc_copyright_pointer indicates the offset in bytes from the start of the Sub_TOC in question to the start of the disc_copyright( ) field. If the value in question is 0, this indicates that the disc-copyright( ) field is absent.
[0044] 10. A 4-byte disc_publisher_pointer indicates the offset in bytes from the start of the Sub_TOC in question to the start of the disc_publisher( ) field. If the value in question is 0, this indicates that the disc_publisher( ) field is absent.
[0045] 11. A variable size Track_List( ) may be present for each one of a plurality of audio tracks to contain an offset information with reference to the start of the TOC in question, plus various further items, such as the name of track and any of a great multiplicity of items that are presumably interesting to a listener of the recording in question.
[0046] [0046]FIG. 6 shows an exemplary structure of an audio area 126 , 128 in FIG. 5. Here, the track area is preceded by Area or Sub-TOC- 1 and succeeded by Area TOC- 2 . These are two identical copies. Another manner of logical conformance may be produced by bit-wise inversion. Anyway, each copy taken separately must contain all information contained in the two TOCs. The locations thereof are for each separate Area TOC given in a higher level Master TOC. A gap between the Track Area and succeeding Area TOC- 2 is not allowed, On the other hand, a gap between preceding Area TOC- 1 and the Track Area is allowed, symbolized by area G, Such gap will generally not contain significant information, in particular, no other TOC or track. Therefore, logically the tack area will abut at both ends to the TOCS. Due to the doubling of the Area TOCs and their mutual distance, any interference therewith through environmental or other influences will usually not be doubled for the two copies. In consequence, the probability for correct storage of all parts of the Area TOO in at least one of the two versions thereof will be practically guaranteed, even without the providing of internal redundancy. Error correcting through such redundancy would often cost an unjustified delay. In fact, if the preceding TOC is correct, the starting of a track may be effected virtually immediately.
[0047] List of related documents:
[0048] (D1) Research Disclosure number 36411, August 1994, p. 412-413
[0049] (D2) PCT/IB97/01156 (PHN 16.452) 1 bit ADC and lossless compression of audio.
[0050] (D3) PCT/IB97/01303 (PHN 16.405), Audio compressor.
[0051] (D4) EP-A 402,973 (PHN 13.241), Audio compression.
[0052] (D5) ‘A digital decimating filter for analog-to-digital conversion of hi-fi audio signals’ by J. J. van der Kam in Philips Techn. Rev. 42, no, 67, April 1986, pp. 230-8.
[0053] (D6) ‘A higher order topology for interpolative modulators for oversampling A/D converters’, by Kirk C. H. Chao et al in IEEE Trans. on Circuits and Systems, Vol 37, no. 3, March 1990, pp. 309-18. | Audio-centered information is stored on a unitary medium by using a Table-of-Contents (TOC) mechanism that specifies an actual configuration of various audio items on the medium. In particular, each one of a set of one or more Track Areas gets at least two mutually logically conforming Sub-TOCs assigned. This allows to retrieve any constituent Sub-TOC part from at least any correct copy of the Sub-TOCs. Furthermore, one or more Master-TOCs are provided for specifically pointing to each of the Sub-TOCs. | 6 |
CROSS-REFERENCE TO RELATED PATENT APPLICATIONS
[0001] This application is a Continuation of U.S. application Ser. No. 12/502,930, filed Jul. 14, 2009, which is a Continuation of U.S. application Ser. No. 11/748,411, filed May 14, 2007 (now U.S. Pat. No. 7,562,243), which is Continuation of U.S. application Ser. No. 10/727,105, filed Dec. 3, 2003 (now U.S. Pat. No. 7,219,249, which claims priority from Provisional Application 60/431425, filed Dec. 3, 2002, all of which are incorporated herein by reference in their entirety.
FIELD
[0002] The present disclosure relates to reducing power requirements of microelectronic devices and, more particularly, to an apparatus and method for reducing power dissipation and energy requirements in high-performance microprocessors.
BACKGROUND
[0003] Modern, high-performance microprocessors use sophisticated instruction scheduling mechanisms and pipelines designed to reorder the startup and completion of instructions in a sequential instruction stream so as to achieve a high-level of processor performance. One common form of such mechanisms is a superscalar microprocessor that is capable of fetching, decoding, issuing, executing, completing and retiring more than one instruction within a single cycle of the clock signal used to synchronize activities at the lowest level in the microprocessor. As used hereinbelow, the term instruction refers to the smallest unit of work that is scheduled independently within a microprocessor.
[0004] In a typical superscalar microprocessor, instructions are fetched from an instruction cache (I-cache) in program order along the predicted path of execution. The instructions are then decoded to resolve inter-instruction dependencies and are then dispatched into a buffer commonly known as the issue queue (IQ). Then, subject to both the availability of execution units (also called function units or FUs), and the input operands of the instruction, each instruction is eventually executed.
[0005] Instructions that are ready for execution, issued from the IQ to the chosen FU, may therefore start as well as finish execution out of program order. To comply with the sequential semantics of the executing program, the processor state as defined by the contents of the committed or architectural registers, as well as the state of the memory, must be updated in program order despite the fact that instructions can complete out of program order. This requirement is met by collecting the results produced out-of-program-order into another buffer called the reorder buffer (ROB). Information stored in the ROB is used to update the processor and memory state into the original program order.
[0006] As instructions are decoded in program order, an entry is simultaneously established in program order in the ROB, which behaves as a first-in, first-out (FIFO) queue. At the time of dispatch, the entry for the dispatched instruction is made at the tail of the ROB. The ROB entry for an instruction can itself serve as the repository of the instruction's results or it may point to the repository of the results within a separate physical register file.
[0007] The process of retiring or committing an instruction involves updating the processor's state and/or the memory state in program order, typically using the information stored in the ROB. Instructions are retired from the head of the ROB. If the ROB entry at the head of the ROB is awaiting the completion of the corresponding instruction, instruction retirement is blocked (i.e., halted) momentarily until the results are correctly produced.
[0008] To process load and store instructions that move data between memory locations and registers, many modern microprocessors also employ a load-store queue (LSQ), which also behaves as a FIFO queue. Entries are established for load and store instructions in program order as the instructions are dispatched, at the tail of the LSQ. Memory operations are started from the LSQ to conform to program ordering.
[0009] In modern microprocessor systems, the overall design strategy has heretofore been a “one-size-fits-all” approach, where the datapath resources like the IQ, ROB, registers and LSQ are set at predetermined, fixed sizes irrespective of the changes in the instantaneous needs of am executing program for these resources. As a result, these resources frequently remain under-utilized. Unused portions of the resources remain powered up, wasting energy and power.
DISCUSSION OF THE RELATED ART
[0010] Canal and Gonzalez (“A low-complexity issue logic”, Proc. ACM Int'l. Conference on Supercomputing (ICS), pp. 327-335, Santa Fe, N. Mex., June, 2000) describe a scheme to reduce the complexity of the issue queue in a microprocessor. Their technique relies on the use of an additional queue, called the “ready queue” to hold instructions whose operands are determined to be available at the time of instruction dispatch. Instructions can be issued from this ready queue without the need to have energy-dissipating logic to check for the availability of operands. The present invention does not use any auxiliary structures to hold instructions and relies on the reduction of power in the issue queue by controlling the amount of resource units that are allocated for the issue queue. This scheme also makes use of an additional structure called the “first use” table to hold instructions that cannot be put into the “ready queue” at the time of instruction dispatching. With the use of this table and the associated logic, it is not clear that this scheme results in an overall power savings. Unlike the Canal et al. scheme, the present invention also reduces power dissipation within other datapath structures such as the reorder buffer, the load-store queue and the register file.
[0011] Folegnani and Gonzalez (“Energy-Effective Issue Logic”, in Proceedings of the Int'l Symposium on Computer Architecture, June 2001, pp. 230-239) describe a FIFO issue queue that permitted out-of-order issue but avoided the compaction of vacated entries within the valid region of the queue to save power. The queue was divided into regions. The number of instructions committed from the most-recently allocated issue queue region in FIFO order (called the “youngest region”) was used to determine the number of regions within the circular buffer that was allocated for the actual extent of the issue queue. To avoid a performance hit, the number of regions allocated was incremented by one periodically; in-between, also at periodic intervals, a region was deactivated to save energy/power if the number of commits from the current youngest region was below a threshold. The energy overhead of the control logic for doing this resizing was not made clear. Additional energy savings were documented by not activating forwarding comparators within entries that are ready for issue or entries that are unallocated. The scheme of Folegnani et al. is thus limited to a FIFO style issue queue design and does nothing to reduce power dissipation in other datapath structures such as the reorder buffer, the load-store queue and the register file. The present invention is applicable to more general styles of issue queue design, including FIFO issue queues. This invention also reduces power dissipations in the reorder buffer, the load-store queue and the register file. Furthermore, unlike the method of the present invention, the scheme of Folegnani et al. relies on continuous measurements of issue queue activity rather than sampled measurements.
[0012] Bahar and Manne (“Power and Energy Reduction Via Pipeline Balancing”, Proceedings of the Int'l Symposium on Computer Architecture, June 2001, pp. 218-229) describe a scheme for shutting off clusters of execution units and some associated register files in the Compaq 21264 microprocessor based on continuous monitoring of the IPC. The dispatch rate was varied between 4, 6 and 8 to allow an unused cluster of function units to be shut off completely. The dispatch rate changes were triggered by the crossing of thresholds associated with the floating point and overall IPC (average number of instructions processed in a clock cycle), requiring dispatch monitoring on a cycle-by-cycle basis. Fixed thresholds were chosen from the empirical data that was generated experimentally. Significant power savings within the dynamic scheduling components were achieved with a minimum reduction of the IPC. The dynamic allocation of the reorder buffer—a major power sink—was left completely unexplored in this study. The scheme of Bahar et al. is limited to a clustered style microprocessor datapath and relies on continuous monitoring of performance. The present invention, on the other hand, saves power by controlling power dissipations within components smaller than clusters and also includes the reorder buffer, avoiding continuous monitoring of performance.
[0013] A portion of the dynamic resource management described in this invention was first described in the publication of Ponomarev, Kucuk and Ghose (“Reducing Power Requirements of Instruction Scheduling Through Dynamic Allocation of Multiple Datapath Resources”, in Proceedings of the 34th International Symposium on Microarchitecture, December 2001, pp. 90-101). Since then, the scheme was extended by S. Dropsho, A. Buyuktosunoglu, R. Balasubramonian, et al., (“Integrating Adaptive On-chip Structures for Reduced Dynamic Power”, in Proceedings of the International Conference on Parallel Architectures and Compilation Techniques (PACT), September 2002), where limited histogramming was used to control resource allocations instead of average queue sizes. Based on the presented results, it is difficult to see any obvious gains in terms of power/performance trade-offs between the method of the present invention and the scheme of Dropsho et al. It is certain, however, that the use of limited histogramming considerably complicates the control logic.
[0014] Buyuktosunoglu, Alper et al. (U.S. Patent Application No. 2002/0053038, May 2, 2002) describe a method and structure for reducing the power dissipation in a microprocessor that relies on dynamic resizing of at least one storage structure in a microprocessor. Unlike the method of Buyuktosunoglu et al., the present invention directly uses the lack of resource units (which indirectly affects performance) to allocate additional resource units to counter any performance drop arising from the lack of resources. The method of Buyuktosunoglu et al. uses the monitored value of the current IPC (average number of instructions processed in a clock cycle) and the prior measured value of IPC to reallocate additional units of the resized resource when a performance drop exceeds a predetermined threshold. However, the performance drop can be caused by reasons other than resizing, such as branch mispredictions and cache misses. Resource allocation is thus not always necessary when such performance drops are noticed. Furthermore, the present invention controls resource unit allocations for a variety of datapath artifacts such as the issue queue, the reorder buffer, the load-store queue and the register file simultaneously and independently to conserve power with minimal impact on performance. Buyuktosunoglu et al. focus on techniques that are driven solely by the activity of the issue queue. A further distinction of the present invention from Buyuktosunoglu et al. uses sampled, non-continuous measurements of usage of each resource that is controlled. Buyuktosunoglu et al. rely on continuous measurements of activity and performance, such as IPC.
[0015] As used hereinafter, the terms datapath resources or simply resources refers to the IQ, ROB, LSQ and register files, etc., but excludes the architectural register file (ARF). The term resource unit hereinafter refers to the basic unit of incremental resource which may be dynamically allocated or deallocated as required for execution of a particular instruction. The terms interval and period are used interchangeably herein.
[0016] Resource usage as used herein is defined by the actual number of valid entries, hereafter referred to as “occupancy”.
[0017] The present invention is primarily intended for reducing dynamic power dissipation arising from switching activity in the microprocessor and similar devices. Power and energy dissipation arising from leakage in the resource units that are deallocated can also be reduced or avoided by using a variety of techniques known to those of skill in the circuit design arts, including, but not limited to, the use of sleep transistors, circuits using dual-threshold devices and substrate biasing.
SUMMARY
[0018] In accordance with the present invention, there is provided an apparatus and method of dynamically estimating the instantaneous resource needs of a program running on a microprocessor. These estimates are used to allocate the minimum number of units of these resources to meet the instantaneous performance needs of that particular program. This approach requires that all allocatable resources be partitionable into independent allocation units that can be incrementally allocated or deallocated. For each of the datapath resources, unused resource units are shut off and isolated from the active, allocated units so as to reduce power dissipations resulting from leakage as well as from switching activities.
[0019] As the program's demands for each resource grow during program execution, further resource units may be independently allocated to each resource. Unused resource units may be reclaimed if the running program is not utilizing them. The reclaimed or deallocated resource units are powered down and isolated from the allocated units to maintain the instantaneous allocation levels at about the right level needed to meet the program's performance needs. The present invention comprises six key features:
[0020] 1) The allocation and deallocation of each type of resource is controlled independently. This is because instantaneous requirements for one type of resource typically vary independently from requirements for a different resource (i.e., there is little, if any correlation between resource requirements). Decisions to deallocate resource units are made periodically, typically at the end of an update period whose duration is predetermined. Resource units may be added within an update period, as described in detail hereinbelow.
[0021] 2) Estimates for the instantaneous need of a program for a specific resource type are obtained through multiple, periodic sampling within the update periods instead of continuous measurements on a cycle-by-cycle basis. The sampling period is predetermined or can be dynamically adjusted. The sampling frequency is typically a multiple of the update frequency.
[0022] 3) At the end of the update period, unused resource units may be deallocated. The deallocation may be gradual, with only one resource unit deallocated at the end of a sampling period, or the deallocation can be more aggressive, with multiple unused resource units being deallocated at the end of the sampling interval. Deallocations typically coincide with the end of an update interval.
[0023] 4) To avoid large penalties on performance, additional resource units are allocated as soon as the true instantaneous demands for the resource exceed the currently allocated units for a predetermined number of times within a sampling interval. When this happens, one or more resource units may be immediately allocated, as availability permits, and a new update period may then be started. Resource allocations thus do not necessarily coincide with the end of the periodic update interval.
[0024] 5) As described in detail hereinbelow, units of certain resources that are organized as FIFO queues may have slightly different allocation and deallocation methods than other types of resources.
[0025] 6) It is possible to use common sampling and update periods for all resources, but these intervals may also be chosen independently for each resource type.
[0026] Although the methods of the present invention are applicable to superscalar processors that utilize dynamic, hardware-implemented scheduling techniques, they may readily be extended to microprocessors that use a combination of static and dynamic scheduling techniques.
[0027] It is therefore an object of the invention to provide a microprocessor or similar microelectronic apparatus wherein various datapath resources may be dynamically sized.
[0028] It is an additional object of the invention to provide a microprocessor or similar microelectronic apparatus wherein various datapath resources are allocated and deallocated in increments.
[0029] It is a further object of the invention to provide a microprocessor or similar microelectronic apparatus wherein various datapath resources are allocated and deallocated dynamically, responsive to the needs for a particular resource by a particular program being executed.
[0030] It is yet another object of the invention to provide a microprocessor or similar microelectronic apparatus wherein resource units may be allocated one-at-a time or, if needed, may be allocated more than one-at-a-time.
[0031] It is an additional object of the invention to provide a microprocessor or similar microelectronic apparatus wherein datapath resources are allocated in accordance with statistics gathered during sampling periods.
BRIEF DESCRIPTION OF THE DRAWINGS
[0032] A complete understanding of the present invention may be obtained by reference to the accompanying drawings, when considered in conjunction with the detailed description, in which:
[0033] FIG. 1 is a schematic block diagram of an architecture of the datapath portion of a first superscalar processor wherein certain datapath resources may be dynamically resized in accordance with the invention;
[0034] FIG. 2 is a schematic block diagram of an architecture of a datapath portion of a second superscalar processor wherein certain datapath resources may be dynamically resized;
[0035] FIG. 3 is a schematic block diagram of an architecture of a datapath portion of a third superscalar processor wherein certain datapath resources may be dynamically resized in accordance with the invention;
[0036] FIG. 4 is a flow chart of a method of allocating non-queued resources in accordance with the present invention;
[0037] FIG. 5 is a flow chart of a method of deallocating non-queued resources;
[0038] FIG. 6 is a flow chart of at set of steps associated with allocating resources used like a FIFO queue; and
[0039] FIG. 7 is a flow chart of a set of steps associated with deallocating resources used like a FIFO queue.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0040] The present invention provides a system that permits the power dissipation and energy requirements of a high-performance microprocessor to be reduced through the dynamic allocation and deallocation of datapath resources, with minimum impact on processor performance.
[0041] The present invention reduces dynamic power dissipation arising from switching activity in microprocessors and similar devices. Power and energy dissipation arising from leakage in the resource units that are deallocated can also be reduced or avoided by using a variety of techniques known to those of skill in the circuit design arts, including, but not limited to, the use of sleep transistors, circuits using dual-threshold devices and substrate biasing.
[0042] Referring first to FIG. 1 , there is shown a schematic block diagram of the datapath portion of a first superscalar microprocessor, generally at reference number 100 . In the superscalar processor 100 , a reorder buffer (ROB) 102 contains the ROB entry set up for an instruction at the time of dispatch. The ROB 102 entry also includes a field, not shown, to hold the result produced by the instruction. ROB 102 operates analogously to a physical register. If an operand value, not shown, has been committed, a dispatched instruction attempts to read operand values from the architectural register file (ARF) 104 directly. If, however, the operand value was generated but has not been committed, a dispatched instruction attempts to read the required operand associatively from the ROB 102 from the most recently established entry for an architectural register.
[0043] Source registers that contain valid data are read into the IQ 106 for the associated instruction. If a source operand is not available at the time of dispatch in the ARF 104 or the ROB 102 , the address of the physical register (i.e., the ROB slot) is saved in the tag field associated with the source register in the IQ 106 for the instruction.
[0044] When a function unit 108 completes processing an instruction, it outputs the result produced along with the address of the destination register for this result. This result is placed on a forwarding bus 112 which runs across the length of the IQ 106 and the LSQ 110 . An associative tag matching process is then used to steer the result to matching entries within the IQ 106 . Since multiple function units 108 may complete processing their respective instructions within a particular cycle, multiple forwarding buses 112 are used. Each input operand field within an IQ 106 thus uses a comparator, not shown, for each forwarding bus 112 . Alternative designs use a scoreboarding logic to identify the destinations of a forwarded result instead of using tag-based result forwarding.
[0045] For every instruction accessing memory, not shown, an entry is also reserved in the LSQ 110 at the time the instruction is dispatched. Because the address used by a load or a store instruction must be calculated, this instruction is removed from the IQ 106 , even if the value to be stored (for store instructions) has not yet been computed. In this case, this value is forwarded to the appropriate LSQ 110 entry as it is generated by one of the function units 108 .
[0046] In the datapath architecture of FIG. 1 , the resources that are allocated and deallocated dynamically following the method of the present invention are: the IQ 106 , the LSQ 110 , and the ROB 102 .
[0047] The superscalar processor datapath 200 shown in FIG. 2 is similar to processor 100 ( FIG. 1 ), with the difference that the destination registers are allocated within a separate physical register file (PRF) 214 . In this case, at the time of dispatching an instruction, a physical register in PRF 214 is allocated for the instruction if its result is destined to a register. In addition, an entry is simultaneously established in ROB 202 for the instruction. The ROB 202 entry for the instruction holds a pointer, not shown, to the destination register of the instruction within the PRF 214 . For processor 200 , the PRF 214 may be managed exactly like a FIFO queue, similar to the ROB 202 .
[0048] An alternative management scheme for the PRF 214 is also possible, requiring a list of allocated registers within the PRF 214 to be maintained.
[0049] In the datapath architecture of FIG. 2 , the resources that may be allocated and deallocated dynamically following the method of the invention are: the IQ 206 , the LSQ 210 , the PRF 214 , and the ROB 202 .
[0050] FIG. 3 depicts the architecture of the datapath portion 300 of yet another superscalar microprocessor that can benefit from the method of present invention. In datapath 300 , registers allocated to hold both committed register values and the results of instructions targeting a register, are held in a common register file, RF 316 . A register alias table, not shown, may be used to point to committed register values within the RF 316 . A similar table may be used to point to most recent instances of an architectural register within the RF 316 when register renaming is used to handle data dependencies.
[0051] In the datapath architecture of FIG. 3 , the resources that may be allocated and deallocated dynamically following the method described in this invention are: the IQ 306 , the LSQ 310 , the RF 316 , and the ROB 302 .
[0052] In addition to application to the three datapath architectures depicted in FIGS. 1 , 2 and 3 , the method of the present invention may also be used in variations of these three architectures where all source register operands are read out at the time of issuing instructions to the function units. In each of these three datapath architectures and their variations, energy and power requirements are reduced using the inventive method by incrementally allocating and deallocating the resources as has been described.
[0053] The method of the present invention may also be applied to datapath architectures that are clustered or to architectures that use a distributed form of the IQ 106 , 206 , 306 , called reservation stations.
[0054] In the inventive method, a predetermined number of units of each type of resource to be dynamically allocated and deallocated is initially allocated. A preset counter, not shown, or other suitable device is used to generate signals indicating the end of an update period. The same counter or a different counter may be used to generate signals that determine when resource usage is sampled. When resource units are added, this preset counter may be reset to begin a new update period.
[0055] In the preferred embodiment, all resources have a common predetermined update period and a common predetermined sampling period. Furthermore, both the update period and the sampling period are chosen to be powers of 2 in the number of clock cycles. It will be recognized that in alternate embodiments of the invention, variations using update and/or sampling periods specific to a resource type may be implemented. These alternate embodiments use sets of counters for generating signals to mark the end of such periods, typically one counter per resource.
[0056] To permit incremental allocation and deallocation of resources, the traditional monolithic forms of these resources are altered to segment each resource type into uniform-sized 15, resource units. The size of each such resource unit is predetermined and is specific to each type of resource. For each resource type, a number of well-known circuit design techniques, such as multiple banking, bitline segmentation or partitioning with shared components can be used to implement: (i) the resource units themselves; (ii) facilities to add further units to an allocated suite of resource units, and (iii) facilities to deallocate certain already-allocated units.
[0057] As a program is run on the system initialized as described above, resource units are added (i.e., allocated) as the program requires a higher resource allocation to maintain its performance. If allocated resource units are determined to be unused at the end of an update period, they may be deallocated. The exact nature of the allocation and deallocation steps is described below.
[0058] Method for the Allocation of Non-Queue Resources
[0059] Referring now to FIG. 4 , there is shown a flow chart of one possible set of steps for allocating resources that do not behave like FIFO queues. Examples of such resources include, but are not limited to the register file (e.g., RF 316 of the datapath of FIG. 3 ), and non-collapsing issue queues, where IQ entries can be allocated or freed up at any position within the queue.
[0060] The process of allocating non-queued resources depicted in FIG. 4 begins with the commencement of an update period by initializing an overflow counter to zero, step 400 . The overflow counter counts the number of times, since the update period started, that resources exceeding current allocations were required. For a non-collapsing IQ (e.g., IQ 306 ), when additional resources beyond the current allocations are needed but not allocated, instruction dispatch is blocked and performance suffers.
[0061] Next, one clock cycle is allowed to elapse, step 405 , and then a check is performed, step 410 , to determine if additional resources (beyond the current allocations) were required in the clock cycle that just elapsed. If additional resources were required, step 410 , the value of the overflow counter is then incremented, step 415 , and the process continues at step 420 where the overflow counter is checked to determine if its count has exceeded a predetermined threshold value, variable OTH.
[0062] If this comparison, step 420 , indicates that the overflow counter has exceeded OTH, it is then necessary to check whether an additional free resource unit is available, step 425 . If no additional free resource units are available, control is transferred to step 440 . Otherwise a resource unit is allocated to increase the current resource allocation, step 430 . After housekeeping tasks are performed, such as clearing variables and counters for keeping various statistics within an update period, and resetting the update period counter to begin a new update period, step 435 , the process shown in FIG. 4 terminates.
[0063] If, however, additional resources are not required, step 410 , program control is passed to step 440 .
[0064] Likewise, if the overflow counter has not exceeded OTH, step 420 , program control is returned to step 440 .
[0065] In step 440 , a check is performed to determine if the current update period has finished. If so, the process of FIG. 4 is terminated. If, however, the current update period has not yet completed, control is returned to step 405 .
[0066] It will be recognized that the value of variable OTH may be specific to the type of resource. It is also possible to vary the value of variable OTH for a single resource over time. Although this does not occur in the embodiment chosen for purposes of disclosure, the present invention encompasses such an additional embodiment.
[0067] It will also be recognized that the process of FIG. 4 may be modified to allocate more than a single free allocation unit of a particular resource when the overflow counter exceeds OTH, step 420 , early in the update cycle. Such a condition indicates a rapidly increasing demand for additional resources which, if not satisfied aggressively, may hurt overall performance. The present invention encompasses all such variations of additional free resource unit allocation.
[0068] Method for the Deallocation of Non-Queue Resources
[0069] Referring now to FIG. 5 , there is shown a flow chart of one possible set of steps required to deallocate a resource of the type allocated according to the process of FIG. 4 . This deallocation process commences when a new update period starts. First, a variable S maintains a running sum of samples usage estimates of the currently allocated resources and is initialized, step 500 . Once variable S is initialized, a sampling period is allowed to elapse, step 505 . At the end of the elapsed sampling period, the number of occupied entries within the allocated resource units is placed into a variable, N, step 510 . In addition, the number of occupied entries within the allocated resource is also added to S, step 515 . It should be noted that the term occupied entries refers to the number of allocated entries within the currently-allocated resource units.
[0070] At the end of a sampling interval, bit vectors indicating the occupancy status of the entries within each allocated unit may be created. Typically, such a bit vector contains a bit for every entry within a resource unit, with a 1 indicating an occupied entry and a 0 indicating a free entry. The sum of the number of 1s in each of these bit vectors may be estimated using known techniques to derive the total number of occupied entries within each allocated resource unit. The total number of occupied entries, N, may then be determined by adding up the already computed sums of the is in the bit vectors for the currently allocated resource units. For example, one possible way to perform such an estimate is to use replicated, parallel logic structures to estimate the sum of is in the aforesaid bit vectors and add them up using a fast tree adder to determine N.
[0071] At the end of a sampling interval, after updating S, step 515 , control is transferred to step 520 .
[0072] If the update period has not yet expired, step 520 , control is returned to step 505 . If, however, the update period is over, step 520 , the average sampled occupancy, A, of the allocated resource units over the update period is estimated, step 525 . If the update period and sampling period are both powers of 2 (as used in the embodiment chosen for purposes of this disclosure), determining this average occupancy, A, does not require any division; the division process is reduced to a simple operation that ignores some lower order bits in S.
[0073] Next, the number of resource units, K, required to accommodate the averaged number of occupied entries, A, is determined by dividing A by number of entries Q within each resource unit, and rounding the result up to the nearest higher integer, step 530 . Again, a division step may be avoided by choosing Q to be a power of 2 . It will be recognized that the value Q may be specific and different for each resource type.
[0074] Next, a check is performed to determine if K is smaller than the number of currently allocated resource units, step 535 . If not, the process of FIG. 5 terminates. If, however, K is smaller than the number of currently allocated resource units, step 535 , a single unit of resource is marked for deallocation, step 540 , and the process of FIG. 5 terminates. The actual deallocation of this marked resource unit takes place when all occupied entries within this unit are consumed (i.e., vacated). No entries are allocated within the resource unit marked for deallocation. In a more aggressive deallocation scheme that emphasizes power/energy savings over performance, more than one allocated resource unit, up to a maximum of the difference between K and the number of currently allocated units, may be marked for deallocation and may eventually be deallocated.
[0075] General Usage of Resources Used Like a FIFO Queue
[0076] The dynamically allocated datapath resources that are used as a queue (such as the ROB, the LSQ and collapsing variations of IQs ( FIGS. 1 , 2 , and/or 3 ) require special considerations for allocations and deallocations because of the circular nature of the FIFO queues. It may be assumed that such queue resources use two pointers, typically head and tail pointers to identify the two extremes of the circular queue. It may also be assumed that both these pointers are first initialized to zero, and then incremented, typically in a circular fashion, to permit wraparound, as the queue grows or shrinks Hereinafter in the description of the FIFO resources and in related methods exemplified in the flow charts of FIGS. 6 and 7 , all arithmetic operations and comparisons performed on the head and tail pointers of the queue take into account the implications of wrap-around. New entries are made at the end identified by tail pointer, after incrementing the tail pointer to point to the next empty entry. Entries are consumed (i.e., removed) from the head of the queue. More specifically, the entry pointed to by the head pointer is consumed and the value of the head is then incremented circularly to point to the next entry to be removed. For the ROB, establishing an entry at the tail of the queue corresponds to the creation of a ROB entry for an instruction at the time that it is dispatched. The consumption of a ROB entry using the head pointer corresponds to the act of retiring an instruction.
[0077] Typically, the resource units allocated to implement FIFO queues are physically adjacent; the queue structure is confined entirely within the allocated resource units. If a resource unit must be deallocated, the unit that is deallocated is the one that has entries with the highest index values. Likewise, when a new resource unit is added, the free unit added is the one adjacent to the currently allocated partition that has entries with the highest index value. The circular nature of these queues, which allow the queue to wrap around within the allocated resource units, adds some complication to the process of allocating and deallocating resource units.
[0078] Method for Allocating Resources Used Like a FIFO Queue
[0079] The decisions leading to the conclusion that additional resource units must be allocated to a resource used as a circular FIFO queue structure are substantially identical to those illustrated in the process of FIG. 4 . However, step 430 is replaced with the multiple exemplary steps shown in the flow chart of FIG. 6 . One significant difference is that the tail end of the FIFO queue should be able to extend into the newly allocated unit (i.e., wrap around).
[0080] The allocation process begins with determining if the value of the head pointer is less than or equal to the value of the current tail pointer, step 600 . This is a normal comparison that ignores the consequences of circular increments to these pointers. This assumption is extended to all pointer comparisons discussed hereafter. If the value of the head pointer is less than or equal to the value of the current tail pointer, step 600 , a free resource unit is added adjacent to the currently allocated resource unit having entries with the highest index values, step 605 . If, however, the value of the head pointer is greater than the value of the current tail pointer, step 600 , a cycle is allowed to elapse and the head and tail pointers are updated to reflect events therewithin, step 610 . Control is then returned step 600 .
[0081] Method for Deallocating Resources Used Like a FIFO Queue
[0082] The decisions leading to the conclusion that previously-allocated resource units may be deallocated in a resource used as a circular FIFO queue structure are substantially identical to those illustrated in the process of FIG. 5 . However, step 540 must be replaced with the multiple exemplary steps shown in the flow chart of FIG. 7 .
[0083] Several checks are needed before the resource unit that has entries with the highest index values among the allocated units can be deallocated:
[0084] a) As in the case of non-queue resources, deallocation cannot be considered until all entries currently within the unit marked for deallocation are consumed;
[0085] b) While the actual deallocation of the unit identified for deallocation is pending, the queue should not be allowed to grow back into that resource unit, and any event (e.g., instruction dispatching, in the case of the ROB) that causes the queue to grow like this should be suspended until the resource unit is deallocated; and
[0086] c) The deallocation should be performed in a manner that allows the queue to wrap around, properly following the deallocation.
[0087] The deallocation process of FIG. 7 begins by setting the variable Limit to the index of the highest numbered slot, step 700 . This includes both allocated and unallocated entries within the resource units that are to remain allocated, but excludes resource units marked for deallocation.
[0088] Next, a test is performed to determine if the value of the head pointer is less than or equal to the value of the tail pointer, step 705 .
[0089] If so, step 705 , a test is performed to determine if the value of the tail pointer is less than or equal to that of the variable Limit, step 710 . If this is true, the block marked for deallocation is actually deallocated, step 725 , and the process of FIG. 7 terminates. If the test, step 710 , is false, one clock cycle is allowed to elapse, step 715 . If, however, the test, step 710 , is false, then one clock pulse is allowed to elapse, step 715 , and the head and tail pointers are updated as needed, step 720 . Control is then transferred to step 705 .
[0090] If, however, the value of the head pointer is greater than the value of the tail pointer, step 705 , a single clock cycle is allowed to elapse, step 730 . A test is then performed, step 735 , to determine if any events in the upcoming clock cycle might cause the tail pointer to extend into the unit marked for deallocation. If any such event exists, it or they are momentarily blocked, step 740 , and control is transferred to step 720 . If no events in the upcoming clock cycle might cause the tail pointer to extend into the unit marked for deallocation, step 735 , control is transferred directly to step 720 .
[0091] It will be recognized by those skilled in the design of processor architecture that the two methods described above for handling the allocation and deallocation of resource units for resources that are used like a circular FIFO queues may be modified to permit the allocation and deallocation of more than one resource item at a time. Consequently, the present invention is not considered to be limited by the embodiment chosen for purposes of disclosure.
[0092] Some general aspects of these inventive methods should be noted. First, new resource units are typically allocated more rapidly than resource units are deallocated. This avoids noticeable performance degradation. Second, the actual deallocation of resource units for resources that are used like a circular FIFO queue can be delayed substantially until the conditions for deallocation are all valid. During this time, events such as instruction dispatching in the case of a ROB may also be momentarily blocked.
[0093] The size estimates developed using these disclose inventive methods may also be used to selectively control clock rates to at least one component of a datapath resource. Such components include an instruction cache, an execution unit, clusters of registers, and function units. It will be recognized that may other microprocessor components may well benefit from such selective clock rate control and the invention is not considered limited to these specifically disclosed components.
[0094] Since other modifications and changes varied to fit particular operating requirements and environments will be apparent to those skilled in the art, the invention is not considered limited to the examples chosen for purposes of disclosure, and covers all changes and modifications which do not constitute departures from the true spirit and scope of this invention.
[0095] Having thus described the invention, what is desired to be protected by Letters Patent is presented in the subsequently appended claims: | There is provided a system and methods for segmenting datapath resources such as reorder buffers, physical registers, instruction queues and load-store queues, etc. in a microprocessor so that their size may be dynamically expanded and contracted. This is accomplished by allocating and deallocating individual resource units to each resource based on sampled estimates of the instantaneous resource needs of the program running on the microprocessor. By keeping unused datapath resources to a minimum, power and energy savings are achieved by shutting off resource units that are not needed for sustaining the performance requirements of the running program. Leakage energy and switching energy and power are reduced using the described methods. | 8 |
CROSS-REFERENCES TO RELATED APPLICATIONS
This application is the U.S. National Stage of International Application No. PCT/DE2008/001586, filed Sep. 26, 2008, which designated the United States and has been published as International Publication No. WO 2009/046694 and which claims the priority of German Patent Application, Serial No. 10 2007 048 486.2, filed Oct. 9, 2007, pursuant to 35 U.S.C. 119(a)-(d).
BACKGROUND OF THE INVENTION
The invention relates to a seat assembly for a land vehicle, sea vessel, or aircraft.
Such a seat assembly forms part of the state of the art within the scope of DE 103 41 483 B3. Firstly, it includes harnesses known from motor vehicles consisting of shoulder and pelvic belts which can be interconnected in a central belt lock. The shoulder and pelvic belts are connected to obliquely-extending longitudinal belts, which, at their lower ends, are coupled by a belt loop passing underneath the buttocks of a user. In addition, in the lower and upper region of the longitudinal belts two back belts are located connecting the longitudinal belts. The upper ends of the longitudinal belts are connected to belt retractors. From the lower ends of the longitudinal belts retaining belts extend obliquely forwardly, viewed in the direction of movement of the vehicle, terminating likewise at belt retractors. The belt loop passing underneath the buttocks of a user is likewise connected to a belt retractor by a retaining belt extending downwardly. Furthermore, a retaining belt extends rearwardly between the upper back belt towards a further belt retractor.
All belt retractors are coupled via control lines to a control box comprising a control lever. Via the control lever the user can set up a free-running state allowing a free belt strap extension and free belt strap retraction, a complete locking state of all belt retractors both against belt strap extension as well as belt strap retraction as well as a locking state of the belt retractors against belt strap extension with free belt strap retraction.
The known seat assembly thus only allows a level adjustment of the belt loop passing underneath the buttocks. Apart from the actual harness, it furthermore requires altogether at least six further belt straps in order to tighten the seat assembly in a vehicle reasonably firmly. In addition, the belt straps require considerable pre-tensioning in order to avoid a rocking motion. However, this state of affairs is in conflict with an individual, constantly available, user-friendly adjustment. Moreover, the belt straps required for the seat assembly are relatively wide and, in many applications, obstruct the view onto operating and display devices in the respective vehicle. Finally, practice has shown that the known fully-textile seat assembly proves very uncomfortable after prolonged use and may, in particular, result in strangulations at the lower extremities of a user.
A textile safety seat for vehicles, in particular in aviation and navigation, is known from DE 43 03 719 A1 which comprises a seat surface, back and side members as well as a safety belt for securing the passengers to be transported. The safety seat is designed as a textile cover encompassing the body of the passenger at the back and on the sides to above head level and includes an entrance, the cover being adapted to be accommodated above and underneath by fastening belts fixed thereon between fastening points, provided on the floor and in the ceiling region of the vehicle in fixed relationship with the vehicle.
From EP 1 398 205 A2 a safety seat is known which can be fitted between the floor and ceiling region of a land vehicle, aircraft or sea vessel by tensioning belts provided above and beneath the seat. The safety harness consists of two pelvic belts as well as two shoulder belts extending from the pelvic belts, and an actuating means in the extension region of the shoulder belts, guided under the seat part towards the entrance region of the seat part. Between each of the shoulder belts and the front tensioning belts a tensioning belt is fitted in resilient manner. This serves to enhance the freedom of movement of the passenger and, in particular, to simplify fastening and unfastening the safety harness.
A further seat assembly forms the subject of U.S. Pat. No. 7,293,818 B2. The latter provides fitting a seat with a rigid frame in an armored vehicle, the said frame being completely decoupled from the vehicle floor, so that in the event of a land mine exploding underneath the vehicle, the forces are not directly transmitted from the vehicle floor to the seat.
A further embodiment of a suspended seat is disclosed in U.S. Pat. No. 3,868,143 A. It is represented by a seat assembly which is fitted both to the floor as well as in the ceiling region by a plurality of tensioning belts.
SUMMARY OF THE INVENTION
Proceeding from the state of the art—it is the object of the invention to provide a seat assembly for land vehicles, sea vessels or aircraft by means of which a user can be protected against vibrations as well as against vertically upwardly-directed acceleration forces and vehicle floor deformations, for example due to mine explosions, with generous adjustability for an adaptation to various user body sizes.
This object is attainable according to the invention by a seat assembly for a land vehicle, sea vessel, or aircraft, including a vertically adjustable seat passing underneath the buttocks of a user, as well as a plurality of flexible connections disposed between the seat and structural parts of the vehicle, wherein the seat forms, at least indirectly, a component of a platform, which can be displaced along connections in the form of cables anchored to the structural parts of the vehicle as well as fixed in the prevailing position on the cables, the cable sections of the cables located above and beneath the platform extending between the platform and the structural parts in such a manner that they are either directed towards the vertical centre axis of the platform or are directed away therefrom.
According to the invention, a stable platform is used which itself is directly configured as a seat or on which a seat can be arranged. The platform is positionally adjustable along cables and fixable in the respective position on the cables. The cables, in their turn, are secured to suitable structural parts of the respective vehicle by way of their upper and lower end sections. It is a further important feature that the cable sections of the cables located above and beneath the platform extend between the platform and the structural parts in such a manner that they are either directed toward the vertical centre axis of the platform or are directed away therefrom.
In the context of the invention it is significant that the platform can be so fixed in place and tensioned by cables in the interior of a vehicle that a user is not only protected against vibrations, but also, preferably in military vehicles (tanks), specifically against vertically upwardly-directed acceleration forces and against vehicle floor deformations due to mine explosions. The seat assembly nevertheless ensures full adjustability for operational adaptation to various body sizes of the user.
The positionally-fixed spatial positioning of the platform can be adjusted in a user-compliant manner via the bracing angles of the cable sections extending above and beneath the platform relative to the platform. In this context, it is only important that all cable sections are uniformly either directed away from the vertical centre axis of the platform or are directed towards the centre axis. As a result thereof, the cable sections each form the edges of a fictitious pyramid which may be equilateral or non-equilateral. Due to varying tension on cables not extending at the same angle in relation to the platform, the inwardly-directed vectors can nevertheless extend through a defined location of the platform and thus bring about the desired position of the platform in space. This allows the invention to be used also in vehicles in which no symmetrical arrangement of the fixation points is provided.
An advantageous further development of the basic concept according to the invention involves the provision of an energy converter, at least indirectly, in the longitudinal orientation of a cable. Preferably, it is the purpose of all energy converters, for example in the case of a mine explosion, to ensure a controlled downward sliding of the platform by converting energy. The energy converter may, for example, be designed as a torsion bar converter, friction converter or a differently configured metal converter.
In this context, it is advantageous that the energy converters are placed under the influence of load-reacting sensors which are integrated in the seat or the anchoring points of the cables on the structural parts. Such sensors are able to detect the mass of the respective user and control the energy converters, adjustable in relation to their load level, in such a manner that optimal energy conversion, which is calculated according to the spatial limitation in the vehicle, takes place at all times.
According to another feature of the invention, the cables are guided by at least one level-adjusting device for the platform. By means of the level-adjusting device the platform may consequently be displaced both parallel in upward and downward direction as well as varied with regard to its inclination.
According to another feature of the invention, the level-adjusting device can be actuated manually or by an electric or hydraulic drive means. Manual actuation may, for example, be done by way of a crank mechanism.
Preferably, the level-adjusting device is integrated in the platform. It may, however, also be provided underneath the platform. In particular, a variation of the inclination of the platform is possible without any difficulty, if two level-adjusting devices are used on the front and rear cables, viewed in the direction of movement of the vehicle.
If an energy converter is integrated in a level-adjusting device, the latter may preferably comprise a crank mechanism. The crank mechanism has an irrotationally arranged gear wheel and is fixed by a blocking device in a respectively desired position in relation to the platform. The cables each loop around a shaft of the level-adjusting device. In the looping region of the cables the shaft is so designed either by special molding or by a friction-enhancing surface that a perfect force-fitting relationship between the cables and the shaft is brought about. The energy converter is then integrated between the blocking device and the looping region of the cables.
In order to fix the respective level of the platform, clamping/release means provided on the platform are associated with the cables. For this purpose, a counter-bearing is provided on one side of a cable and clamping members on the other side thereof. The clamping members can be lifted off the cables by a release unit, which is so configured that a clamping action is cancelled only in the direction in which the platform is to be displaced along the cables. The clamping/release means permits a user to very rapidly plunge from a higher into a lower seating position, should this be necessary for safety reasons, for example from a look-out position in a tank into the protecting interior thereof.
According to another feature of the invention, in order to support the pelvic- and kidney regions of a user and in order to create a large-surface backrest, textile pelvic- and back bracings are provided between the rearward cable sections, viewed in the direction of movement of the vehicle, located above the platform. The back bracing may in this context consist of a wide cloth while for the pelvis preferably one or two narrower belt straps are provided between the cable sections.
According to another feature of the invention, it is, however, also conceivable to provide a molded part, adapted to the back region of a user, between the rearward cable sections, viewed in the direction of movement of the vehicle, located above the platform. This molded part is then of an ergonomic and/or safety-promoting shell-like configuration.
In addition, it is advantageous to provide textile pelvic- and shoulder bracings between the lateral cable sections, located one behind the other, viewed in the direction of movement of the vehicle, and provided above the platform. These bracings serve as lateral support of a user in the pelvic- and shoulder regions.
In this context, it is then advantageous that the shoulder bracings are of net-like design. Such bracings permit laterally-directed vision of the user and also better communication with other passengers.
If a seat, in particular an ergonomic seat, which is displaceable in the direction of movement of the vehicle and fixable in the respective position, is provided on the platform, this seat can then be connected to the platform via rails and displaced along the rails.
According to another feature of the invention, it is possible for such seat to be level-adjustable in relation to the platform.
It is further conceivable that the seat is transversely adjustable on the platform, at least to a limited extent.
According to another feature of the invention, the backrest inclination of the seat can be adjusted so that user comfort is increased.
In order to also adequately protect the foot region of a user, it is appropriately provided that, viewed in the direction of movement of the vehicle, a footrest is arranged upstream of the platform, which is supported in a height and/or inclination-adjustable manner, as the case may be, by cables secured to the structural parts of the vehicle. The footrest may be of ergonomic design. It may, however, also merely consist of a simple platform.
Finally, the seat can be equipped, at least indirectly, with restraining belts. These may in this context be represented by a seat-integrated restraining system or restraining systems may be used which are provided on the vehicle body.
BRIEF DESCRIPTION OF THE DRAWING
The invention is elucidated in more detail in what follows by way of the embodiments illustrated in the drawings.
There are shown in:
FIG. 1 in a schematic perspective view a seat assembly for a land vehicle, sea vessel or aircraft;
FIG. 2 likewise in a schematic perspective view a further embodiment of a seat assembly for a land vehicle, sea vessel or aircraft;
FIG. 3 again in a schematic perspective view a level-adjusting device for the seat assemblies according to FIGS. 1 and 2 ;
FIG. 4 in a schematic perspective view, partially in section, a further embodiment of a level-adjusting device for the seat assemblies according to FIGS. 1 and 2 ;
FIG. 5 a front view, on a larger scale, of detail V of the level-adjusting device of FIG. 4 , together with an energy converter;
FIG. 6 in a schematic view, partially in section, a clamping/release means for the seat assemblies of FIGS. 1 and 2 ;
FIG. 7 in a schematic perspective view a third embodiment of a seat assembly for a land vehicle, sea vessel or aircraft;
FIG. 8 in a schematic perspective view a fourth embodiment of a seat assembly for a land vehicle, sea vessel or aircraft;
FIG. 9 in a side elevation, shown schematically, a footrest for a seat assembly according to FIG. 1 , 2 , 7 or 8 and
FIG. 10 in a schematic perspective view a further embodiment of a footrest for the seat assemblies of FIG. 1 , 2 , 7 or 8 .
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
In FIG. 1 a seat assembly for a land vehicle, sea vessel or aircraft, not illustrated in more detail, is denoted by 1 . Such a vehicle may, for example, be represented by a military vehicle, such as a tank.
The seat assembly 1 comprises a stable rectangular platform 2 . On the platform 2 rails 3 are provided, alongside which a seat 4 for a user, not illustrated in more detail, can be secured in a displaceable manner and in any particular position. The seat 4 is designed to be ergonomic and comprises a backrest 6 the inclination of which can be varied about an axis 5 .
The platform 2 can be displaced in its corner regions 7 along cables 9 , 10 , 11 , 12 , anchored to the structural parts 8 of the vehicle, as well as positionally secured in the respective position to the cables 9 - 12 in a manner to be described in more detail below. In the embodiment of FIG. 1 the cable sections 9 a - 12 a , 9 b - 12 b respectively, extend above and beneath the platform 2 in such a manner that—starting from the platform 2 —they are directed away from the vertical centre axis MA of the platform 2 . As shown, the cable sections 9 a - 12 a , 9 b - 12 b , located above and beneath the platform 2 , run parallel to one another. However—starting from the platform 2 —they may also be so arranged that, on the one hand, the cable sections 9 a - 12 a above the platform 2 and, on the other, the cable sections 9 b - 12 b underneath the platform 2 form the longitudinal edges of a fictitious pyramid, as it were.
In the seat assembly 1 a of FIG. 2 as well, a stable rectangular platform 2 is provided which can be displaced along its corner regions 7 by cables 9 - 12 , anchored to the structural parts 8 of the vehicle, as well as positionally secured in the respective position to the cables 9 - 12 . It can be seen, however, that now the cable sections 9 a - 12 a , 9 b - 12 b respectively, extending between the platform 2 and the structural parts 8 are directed towards the vertical centre axis MA. This bracing permits to position and secure the platform 2 in space by way of the bracing angles W between the cable sections 9 a - 12 a , 9 b - 12 b and the vertical line V in relation to the plane of the platform 2 as well as by the forces applied to the cable sections 9 a - 12 a , 9 b - 12 b the vectors VE of which intersect at a reference point RP. The reference point RP results from the point of intersection of the axes A and AA of the platform 2 . Each cable section 9 a - 12 a , 9 b - 12 b may adopt a different bracing angle W in relation to the platform 2 as long as the basic direction of all cable sections 9 a - 12 a , 9 b - 12 b is adhered to.
The embodiment of a platform 2 , shown schematically in FIG. 3 , shows a level-adjusting device 13 with the aid of which the platform 2 can be displaced parallel to itself in upward or downward direction. It comprises four shafts 14 arranged crosswise and pivotally in the platform 2 , said shafts being coupled at their inner ends via a bevel gear mechanism 15 . A crank mechanism 16 is provided on the outer extremity of a shaft 14 . The cables 9 - 12 are looped once or several times around the shafts 14 in the vicinity of the outer extremities of the shafts 14 . When the crank mechanism 16 is turned, all shafts 14 rotate uniformly so that the platform 2 is displaced along the cables 9 - 12 as a result thereof.
In the embodiment of a level-adjusting device 13 a according to FIG. 4 , two shafts 14 are pivotally mounted parallel to one another in a platform 2 . The two shafts 14 are interconnected via a transmission 17 . On the extremity of a shaft 14 projecting from the platform 2 a crank mechanism 16 is provided. The cables 9 - 12 pass vertically through the platform 2 and are looped around the end regions of the shafts 14 . If the crank mechanism 16 is rotated, the platform 2 can be displaced parallel to itself in upward or downward direction.
This embodiment may, however, also be modified to the effect that no transmission 17 is provided, but that instead thereof both shafts 14 are provided with a crank mechanism 16 . In this embodiment, if both crank mechanisms 16 are actuated accordingly, the inclination of the platform 2 can be changed so that the seat inclination may be adapted to the respective user.
FIG. 5 illustrates schematically the region V of FIG. 4 . It can be seen that the crank mechanism 16 is rigidly connected to a gear wheel 18 . The gear wheel 18 may be secured by a blocking device 19 , not shown in detail, in a desired position in relation to a platform in accordance with FIG. 1 or 2 or—as will still be elucidated— FIG. 7 or 8 , respectively. The cable, for example cable 9 , loops around the shaft 14 . In the looping region 20 the shaft 14 is provided with a friction enhancing surface 21 so that the flow of forces between the cable 9 and the shaft 14 is improved. Between the shaft 14 and the gear wheel 18 an energy converter 22 , not illustrated in detail, is provided which may, for example, be designed as a torsion bar converter.
The embodiment according to FIG. 5 may, of course, also be used in the embodiment of FIG. 3 .
From FIG. 6 the principle of a clamping/release means 23 for a platform 2 is apparent. On the one side of a cable, for example cable 9 , a toothed counter-bearing 24 can be seen. In the upper region the counter-bearing 24 comprises downwardly-pointing teeth 25 and in the lower region upwardly-pointing teeth 26 . On the other side of the cable 9 two pivotal, toothed clamping members 27 , 28 are provided, which are coupled to a release unit 29 . The release unit 29 is so designed that it can be used to release the clamping members 27 , 28 individually from the cable 9 . If, for example, the platform 2 is to be displaced in upward direction, the upper clamping member 27 is released from the cable 9 , while the lower clamping member 28 is released from the cable 9 when the platform 2 is displaced in downward direction. It can further be seen that according to the respective direction of displacement the teeth 25 , 26 on the counter-bearing 24 and the teeth 30 , 31 on the clamping members 27 , 28 are orientated identically.
The seat assembly 1 b apparent from FIG. 7 schematically shows a platform 2 , designed directly as a seat, which can be displaced along cables 9 - 12 , anchored to structural parts 8 of the vehicle, as well as positionally secured to the cables 9 - 12 in a prevailing position in the manner already described above. The cable sections 9 a - 12 a and 9 b - 12 b above and beneath the platform 2 are directed away from the platform 2 .
Between the rearward cable sections 11 a , 12 a , viewed in the direction of movement of the vehicle, located above the platform 2 , a large-surface textile back bracing 32 is provided in the back region. Beneath this back bracing 32 two, in comparison, narrower, belt-like pelvic bracings 33 are located which serve to support the pelvic- and kidney regions of a user.
FIG. 7 further shows by dashed lines that instead of the back- and pelvic bracings 32 , 33 a shell-like molded part 34 of ergonomic and/or safety-promoting design, adapted to the back region of a user, may be provided between the rearward cable sections 11 a , 12 a , viewed in the direction of movement of the vehicle, located above the platform 2 .
The seat assembly 1 c according to FIG. 8 corresponds initially to the seat assembly 1 b according to FIG. 7 as regards the platform 2 , the orientation of the cables 9 - 12 as well as the back- and pelvic bracings 32 , 33 .
In addition, however, it can further be seen that for the lateral support of a user textile pelvic- and shoulder bracings 35 , 36 are provided between the lateral, successive cable sections 10 a , 11 a , viewed in the direction of movement of the vehicle, provided above the platform 2 . These serve to support the pelvic region as well as the shoulder and head regions. The shoulder bracing 36 is designed like a net and permits a laterally-directed view as well as easier communication with other passengers. FIG. 8 shows only one respective pelvic- and shoulder bracing 35 , 36 . It goes without saying that on the other side as well such pelvic- and shoulder bracings 35 , 36 may be provided between the upper cable sections 9 a and 12 a.
FIG. 9 , in a basic side elevation, illustrates a footrest 37 for a user B, arranged upstream of a platform 2 , viewed in the direction of movement of a vehicle. The footrest 37 is adapted to the foot region of the user B and is supported by cables 38 anchored to structural parts 8 of the vehicle. In this context, it is conceivable that the footrest 37 is likewise height- and/or inclination-adjustable. The cables 38 may extend in space according to the embodiments of FIG. 1 , 7 or 8 .
FIG. 10 shows a platform-like footrest 37 a . This footrest 37 a is anchored to a structural part 8 of a vehicle by an upwardly-directed vertical cable 39 and is anchored to structural parts 8 of the vehicle via four further downwardly-directed cables 41 fitted to the corner regions 40 .
For the embodiments of FIGS. 9 and 10 integrated level-adjusting devices 13 , 13 a are conceivable as have been elucidated with reference to FIGS. 3 to 6 . | The seat assembly ( 1 ) for a land vehicle, sea vessel, or aircraft comprises a vertically adjustable seat ( 4 ) supporting the buttocks of a user and a plurality of cables ( 9 - 12 ) disposed between the seat ( 4 ) and structural parts ( 8 ) of the vehicle. The seat ( 4 ) forms at least indirectly the component of a platform ( 2 ), which can be displaced along the cables ( 9 - 12 ) and fixed in the respective position on the cables ( 9 - 12 ). The cable sections ( 9 a - 12 a, 9 b - 12 b ) located above and beneath the platform ( 2 ) extend between the platform ( 2 ) and the structural parts ( 8 ) such that they either point toward the vertical center axis (MA) of the platform ( 2 ) or are directed away therefrom. The cables ( 9 - 12 ) can be guided via at least one height adjustment device. | 1 |
FIELD OF THE INVENTION
[0001] The present invention is directed to a support for heavy lawn furniture particularly wooden lawn furniture such as cedar redwood chaises, picnic tables and the like. The support attaches to a furniture leg of various shapes and dimensions and provides for ease of movement of the furniture, directing water away from the base of the leg of the furniture preventing mildew and dry rot from forming on a leg and deteriorating the appearance or quality of the furniture.
BACKGROUND OF THE INVENTION
[0002] Heavy lawn furniture of wood or plastic composites has become increasingly popular, particularly cedar redwood and the like which can be left outdoors in all types of weather. While such furniture is esthetically attractive it is difficult to move such as when mowing the lawn or when replacing the furniture for reasons of shade, sun or the like. In trying to move such heavy furniture it often requires two people or awkward lifting one end and then the other. It normally cannot be slid across the lawn since the heavy (normally rectangular) legs will dig into the lawn damaging both the lawn and the furniture.
BRIEF SUMMARY OF THE INVENTION
[0003] It is a principal object of the present invention to provide a support for such lawn furniture which will provide extended surfaces at the bottom of each leg, which will provide a lower unit pressure on the lawn and which will engage the lawn in such a way that the furniture can be easily slid across the lawn without damaging the lawn. The invention, in a preferred form, comprises a unitary molded element having an area for engaging the surface of the lawn which has an area preferably at least five times greater than the area of the bottom of the leg. This unitary structure preferably has means for supporting the bottom of a variety of leg designs so that most of the bottom of the leg is spaced from the support and prevented from coming in contact with a ground surface such as a lawn to permit easy drying of the bottom of the leg and to prevent dryrot.
[0004] A set of upstanding walls are formed on the upper surface of the support with one or more walls having an aperture for insertion of a fastener, screw, bolt or other attachment fitting or device to engage the sides of the leg to secure the support to the furniture leg. Alternatively, a spacer may be inserted in the support and provide accommodation for attachment points for legs of varying shapes and dimensions. A round, square, rectangular or other shaped furniture leg may be secured directly to the support or be secured to the inserted spacer and the support to allow movement of the furniture with the support, the support providing a smooth surface to slide the furniture over a ground surface of grass, concrete, wood or other surface material.
[0005] The present invention is directed to a support for engaging the bottom of a lawn furniture leg, the support comprising a unitary molded element having upper and bottom surfaces each with an area at least five times greater than the area of the bottom of the leg; a first upstanding wall in parallel with a second upstanding wall, a third upstanding wall in parallel with a fourth upstanding wall and perpendicular to the first and second walls for engaging the sides of the leg and securing the support to the leg; and wherein the bottom of the leg is spaced above the top surface of the support a sufficient distance to permit drainage of water under the leg whereby to prevent dryrot to the leg.
[0006] The present invention is also directed to a support for engaging the bottom of a lawn furniture leg; the support comprising a unitary molded element having upper and bottom surfaces each with an area at least five times greater than the area of the bottom of the leg; a plurality of upstanding walls on the upper surface for engaging the sides of the leg and securing the support to the leg; means for supporting the bottom of the leg so that the leg bottom is spaced above the top surface of the support a sufficient distance to permit drainage of water under the leg whereby to prevent dryrot to the leg.
[0007] The present invention is also directed to method for supporting a furniture leg comprising the steps of forming a unitary molded element, the element having an upper and lower surface each with an area at least five time greater that the area of the bottom of the leg; forming a first upstanding wall in parallel with a second upstanding wall on the molded element; forming a third upstanding wall in parallel with a fourth upstanding wall on the molded element, the third and fourth walls perpendicular to and at a distance closer than the distance between the first and second walls; securing a furniture leg between one of at least the first and second and third and fourth walls; and supporting the leg above the upper surface of the molded element to permit drainage of water under the leg whereby to prevent dryrot.
[0008] These and other features, advantages and improvements according to this invention will be better understood by reference to the following detailed description and accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] The above-mentioned and other features and advantages of this invention, and the manner of attaining them, will become more apparent and the invention will be better understood by reference to the following description of an embodiment of the invention taken in conjunction with the accompanying drawings, wherein:
[0010] FIG. 1 is a diagramatic schematic top view of a preferred embodiment of support of the present invention.
[0011] FIG. 2A is a diagramatic schematic sectional view along the line A-A of FIG. 1 showing various features of the support of the present invention.
[0012] FIG. 2B is a diagramatic schematic sectional view along the line B-B of FIG. 1 showing various features of the support of the present invention.
[0013] FIG. 3 is a diagramatic perspective view of the preferred embodiment of the support of the present invention.
[0014] FIG. 4 is a diagramatic perspective view of a further embodiment of the support of the present invention.
[0015] FIG. 5A is a diagramatic perspective view of a spacer for the further embodiment of the present invention.
[0016] FIGS. 5B and 5C are a diagramatic schematic of first and second side views of the spacer for the further embodiment of the present invention.
[0017] FIG. 5D is a diagramatic schematic top view of the spacer for the further embodiment of the present invention.
[0018] FIG. 5E is a diagramatic schematic top view of a further embodiment of the spacer with a rounded interior for the further embodiment of the present invention.
[0019] FIG. 6 is diagramatic view of a perspective view of the further embodiment of the support of FIG. 4 and the insert of FIG. 5A-5D .
DETAILED DESCRIPTION OF THE INVENTION
[0020] Referring to FIG. 1 , the support or lawn coaster which is generally shown as 10 comprises a unitary molded structure 12 having a circular edge 14 . As seen best in FIG. 2A and 2 B, the support 12 has a bottom surface 16 and an upper surface 18 . In a first embodiment, the upper surface 18 supports a set of engaging walls 20 to align a furniture leg 21 of wood or plastic composite within the engaging walls 20 . The engaging walls 20 are aligned along axis A and form a cross with a first dimension D between a first set of engaging walls 20 a of a longer length than the distance between a second set of engaging walls 20 b aligned along axis B. The second set of engaging walls 20 b having a shorter distance between them as denoted by the second dimension d in FIG. 1 . The furniture leg shown at 21 in FIGS. 2A and 2B as dotted lines may be of various dimensions in width with the first set of engaging walls 20 a accommodating a furniture leg 21 of a wider width of between 1¼ inches and 1½ inches. The second set of engaging walls 20 b may accommodate a narrower width of furniture leg of between ¾ inches and 1 inch. The furniture leg is placed between the appropriate first or second set of engaging walls that accommodates the dimensions of the furniture leg, the leg may then extend through the cross area X of the support 12 .
[0021] The engaging walls 20 may be on the order of 3/16 inches in width and 1 inch to 1½ inches in height and may be supported by one or more structural braces 24 to provide rigidity to the wall and maintain the wall in an upright position. The braces 24 may be arranged perpendicularly to the engaging wall 20 as shown in FIG. 1 or may be affixed to the support 12 at an acute angle to the wall 20 . In providing additional strength to the upstanding wall 20 , the braces 24 transmit lateral motion from the furniture leg 21 to the element 12 when it is to be slid across the ground. It is to be appreciated that the braces may not be necessary in view of the molded nature of the integral engaging walls 20 a - 20 b being integrally connected at about ninety degrees providing inherent support to such walls.
[0022] As can be seen, the bottom of the furniture leg 21 is supported by ribs 22 provided on the upper surface 18 between each of the first and second sets of securing members 20 so that there is a space between leg 21 and upper surface 18 . The supporting ribs 22 may be at a distance of between 1/32 inches and ⅛ inches between each rib to adequately support furniture legs of various dimensions that are inserted between each of the engaging walls 20 . The ribs 22 are contoured to create a slant from the cross area X down to the circular edge 14 of the support 12 . The spaces S formed between the ribs 22 , provides ventilation to the furniture leg 21 to disperse water from rain or dew thereby controlling and minimizing dry-rot.
[0023] As shown particularly in FIGS. 2A and 2B the interior 26 of the bottom surface 16 is slightly concave to assist in maneuvering a heavy piece of furniture across an irregular surface, each of the legs 21 of the furniture having a support 12 . This is an important aspect so that the edge defined by the perimeter 14 does not catch on the ground. Similarly, the upper surface 18 adjacent the rounded perimeter 14 may be slightly concave as indicated at 14 a to facilitate molding of the product as shown in FIG. 2A or have an angular slant 15 as shown in FIG. 2B . The perimeter 14 a of the bottom surface also has upturned peripheral edges to assist in gliding of the support 12 over a ground surface G.
[0024] As seen in FIG. 2A the upper surface 18 has a slightly angular slant 28 to provide drainage so that any rain water hitting the element is drained towards the perimeter 14 and away from the bottom of the furniture leg 21 which is supported at the center of the element 12 .
[0025] As a result of the above described construction the element 12 provides a support which has a relatively smooth surface which distributes the load of the furniture over a large area and provides a smooth surface which can be readily slid across the surface of the ground. Thus, the furniture can be readily moved from place to place so as to reposition the furniture for whatever reason, such as mowing the lawn or to move it in or out of shade, as desired.
[0026] In a preferred embodiment of the invention the product is molded of a plastic material such as low density polyethylene, or polypropylene. In one preferred form the support 12 is on the order of 7⅝ inches in diameter and has a thickness on the order of 5/32 inches. It can be attached to the bottom of the furniture leg by means of screws, pins or other attachments (not shown) which pass through an aperture 30 in the wall 20 . The spacing between the first set of engaging walls 20 is preferably about 2 inches and the walls 20 are slightly tapered outwardly to permit easy attachment to the bottom of the furniture leg 21 . The spacing between the second set of engaging walls 20 is preferably about 1 9/16 inches
[0027] Ribs 22 also reinforce the central portion 26 of the support 10 . Molding sprues 20 c may also be formed to reinforce the upstanding walls 20 . As shown in FIG. 3 , the engaging walls 20 create a slot for the insertion of a furniture leg 21 . The dimensional width of the leg should 21 fit snugly between the chosen set of engaging walls 20 and allow for the insertion of a pin or screw through the aperture 30 and a hole drilled or formed in the furniture leg 21 . A separate pin or screw may be inserted from each side of the furniture leg 21 or the hole may be formed completely through the leg 21 and a bolt and nut inserted through the walls 20 and leg 21 may be used to secure the support 12 . Other optional methods of attachment are contemplated. The leg 21 may extend through the cross area X to allow the leg 21 to also be secured through the corresponding set of engaging walls 20 on the other side of the support 12 .
[0028] In a further embodiment shown in FIG. 4 , a support 11 has engaging walls 40 that are formed with a first mid-portion 42 of a shorter length and a second mid-portion 43 of a longer length, the mid-portions facilitating the insertion of a spacer 44 shown in FIGS. 5A-5E . The engaging walls 40 are formed in similar dimensions to the first and second set of walls described above with a dimension D between the first set of engaging walls 40 a longer than the dimension d between the second set of engaging walls 40 b . Braces to support the walls 40 and slanted ribs 22 with spacing S may be formed in the support 13 as described above to provide ventilation to the furniture leg 21 and minimize dry rot.
[0029] As shown in FIGS. 5A-5E , the spacer 44 is molded of a rigid plastic material such as low density polyethylene, or polypropylene. The spacer 44 is formed with a first narrower side 46 to complement the dimensions of the first mid portion 42 of the engaging walls 40 and a second longer side 47 to complement the second mid-portion 43 of the wall. The remaining sides of the spacer are at a length that complements the distance between the first set of engaging walls 40 a D and the second set of engaging walls 40 b d with a first longer side 48 at length D and a second shorter side 49 at length d. Side views and a top view of the spacer are shown in FIGS. 5B-5E respectfully. One or more of the mid-portion sides 46 , 47 of the spacer 44 may have an aperture 50 for insertion of a pin or screw (not shown) to attach the support 11 and spacer 44 to a furniture leg 21 . Alternatively, one of the longer or shorter sides 48 and 49 of the spacer 44 may also have an aperture that provides for the spacer 44 to be attached to a furniture leg 21 and the support 11 to be attached to the spacer 44 at one of the mid-portion apertures 50 . In a further embodiment as shown in FIG. 5E , the spacer may have a rounded interior portion 54 to accommodate round furniture legs of smaller dimensions. Other shapes for the interior portion are contemplated, such as oval or rectangular. One or more apertures 50 may be drilled through one or more sides of the round or other shaped interior portion to attach the support to a furniture leg of different shapes and dimensions.
[0030] As shown in FIG. 6 , the spacer 44 fits snugly within the engaging walls 40 to secure an oval or round shaped furniture leg 21 within the spacer. An aperture through each of the mid-portions 42 , 43 of the support engaging walls provides for the insertion of a pin, screw or other attachment fitting to secure the circular or oval leg to the support. The walls of the spacer may be of a dimension similar to the engaging walls or may be thicker with the interior shaped in a rounded curve as shown in FIG. 5E . It is also to be appreciated that the mid-portions 42 , 43 do not have to be linear, but may also be rounded to accommodate a rounded furniture leg within the engaging walls 40 , with or without a spacer as described above.
[0031] The invention has been described in detail with particular reference to certain preferred embodiments thereof, but it will be understood that variations and modifications can be effected within the spirit and scope of the invention. | A support is provided for positioning on the base of a lawn furniture leg of various shapes and dimensions. The support has an area that is at least five times the area of the bottom of the leg to distribute the load over a large area. This permits easy sliding of the leg across a lawn. The support is arranged to prevent prolonged contact of the leg with a source of moisture. In addition, the support provides venting to the bottom of the leg to minimize dry-rot. | 8 |
BACKGROUND OF THE INVENTION
[0001] Embodiments described herein relate to a diesel engine exhaust treatment system and method, and more particularly, to an exhaust treatment system and method which utilize a platinum group metal trapping device to prevent contamination of SCR catalysts.
[0002] Diesel engine exhaust treatment systems are known for use in converting gaseous emissions such as nitrogen oxides (NO x ) to environmentally acceptable compounds. Such systems typically include a diesel oxidation catalyst (DOC), a selective catalytic reduction catalyst (SCR), and a diesel particulate filter (DPF).
[0003] Diesel oxidation catalysts are placed in the exhaust gas stream of a diesel engine and typically contain platinum group metals (PGM), base metals, or a combination thereof. These catalysts promote the conversion of CO and HC emissions to carbon dioxide and water.
[0004] Selective catalytic reduction catalysts (SCR) are used to convert NO x to N 2 and typically comprise a base metal and utilize an ammonia reductant, typically in the form of aqueous urea, which is injected into the exhaust stream downstream from the diesel oxidation catalyst. After water vaporization and urea hydrolysis, the formed ammonia reacts with NO x in the exhaust gas stream on the SCR catalyst to form N 2 .
[0005] A diesel particulate filter (DPF) collects soot or particulate matter from engine exhaust. A precious metal catalyst selected from platinum group metals is typically coated on the DPF for the removal of CO, HC, and NH 3 slip.
[0006] It has been observed that treatment systems which include diesel oxidation catalysts washcoated with platinum group metals may lose trace amounts of platinum or other platinum group metals under certain conditions, such as high temperature operation. The trace amounts of platinum group metals from the DOC sublime and then accumulate on the SCR catalyst positioned downstream from the DOC such that the function of the SCR catalyst is inhibited. This is due to the high activity of platinum group metals for ammonia oxidation which results in little or no ammonia being available for the SCR reaction. In addition, because platinum group metal catalysts generate NO x and N 2 O from ammonia, an increase in NO x levels could actually result when the SCR is inhibited due to platinum group metal poisoning. It has been discovered that platinum levels as low as 0.0005 wt % can have a significant impact on SCR performance. See, Jagner et al., “Detection, Origin, and Effect of Ultra-Low Platinum Contamination on Diesel-SCR Catalysts,” SAE International Paper No. 2008-01-2488, (2008).
[0007] Accordingly, there is a need in the art for a diesel engine exhaust system which prevents the deposition of platinum group metals on an SCR positioned downstream from a diesel oxidation catalyst, and to a system which efficiently achieves conversion of combustion components and removal of particulates in the exhaust gas.
SUMMARY OF THE INVENTION
[0008] Embodiments of the invention meet those needs by providing a diesel engine exhaust treatment system and method which includes a platinum group metal trap positioned downstream from a diesel oxidation catalyst. The platinum group metal trap functions to trap trace amounts of platinum group metals released from the diesel oxidation catalyst so as to prevent deposition of the metals on an SCR catalyst positioned downstream from the diesel oxidation catalyst.
[0009] According to one aspect, a diesel exhaust gas treatment system is provided which comprises a diesel oxidation catalyst comprising a platinum group metal positioned in an exhaust stream, a platinum group metal trap positioned downstream from the diesel oxidation catalyst which traps platinum group metals released from the diesel oxidation catalyst, and a selective reduction catalyst (SCR) positioned downstream from the platinum group metal trap.
[0010] The diesel oxidation catalyst preferably comprises a combination of platinum and palladium. The SCR catalyst preferably comprises zeolite and a base metal selected from copper and iron.
[0011] In one embodiment, the platinum group metal trap comprises cerium oxide. In another embodiment, the platinum group metal trap comprises a perovskite material. The perovskite material preferably comprises CaTiO 3 .
[0012] The treatment system preferably further includes a diesel particulate filter which may be positioned downstream from the SCR catalyst, downstream from the platinum group metal trap, or upstream from the platinum group metal trap.
[0013] In another embodiment, the treatment system further includes a lean NO x trap which may be positioned either upstream or downstream from the platinum group metal trap.
[0014] The treatment system preferably further includes a reductant delivery system for providing a source of ammonia or urea to the exhaust stream. The reductant delivery system is preferably positioned directly upstream from the SCR catalyst.
[0015] In another embodiment, a method for treating diesel engine exhaust gases is provided in which exhaust gases are passed through the exhaust gas treatment system containing the platinum group metal trap between a diesel oxidation catalyst and SCR catalyst, such that the platinum group metal trap reduces platinum group metal contamination on the SCR catalyst in comparison with an exhaust system which does not include a platinum group metal trap. The method preferably includes providing a source of ammonia or urea to the exhaust stream.
[0016] Accordingly, it is a feature of embodiments of the present invention to provide a diesel exhaust gas treatment system and method which utilizes a platinum group metal trap to trap platinum group metals released from a diesel oxidation catalyst to prevent contamination of an SCR catalyst.
[0017] Other features and advantages of the invention will be apparent from the following description, the accompanying drawings, and the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] FIG. 1 is a schematic illustration of a diesel engine exhaust treatment system in accordance with an embodiment of the invention;
[0019] FIG. 2 is a schematic illustration of another embodiment of the invention including a lean NO x trap and a diesel particulate filter;
[0020] FIG. 3 is a schematic illustration of another embodiment of the invention;
[0021] FIG. 4 is a schematic illustration of another embodiment of the invention;
[0022] FIG. 5 is a schematic illustration of another embodiment of the invention; and
[0023] FIG. 6 is a schematic illustration of another embodiment of the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0024] In a preferred embodiment, an exhaust treatment system is provided which includes a platinum group metal trap positioned between a diesel oxidation catalyst and an SCR catalyst. The system reduces the likelihood of contamination of the SCR catalyst so that its performance is not inhibited. Thus, the system including the platinum group metal trap reduces platinum group metal contamination when compared to an exhaust treatment system which does not include the trap, while still providing efficient removal of NO x .
[0025] The platinum group metal trapping device may comprise a monolith washcoated with cerium-containing oxides at a loading of about 30 to 300 g/L. While not wishing to be limited by any specific theory of operation, it is believed that the strong interaction of cerium oxide with platinum facilitates the trapping of platinum group metals sublimed/released from the upstream DOC.
[0026] Alternatively, the platinum group metal trapping device may comprise a Perovskite material having the formula ABO 3 , where A-B includes, but is not limited to, Ca +2 —Ti +4 , Ba +2 —Ti +4 , Ln +3 —Co +3 , or La +3 —Fe +3 . Perovskite materials with relatively high surface areas may be prepared by a sol-gel method using the corresponding metal alkoxides. The perovskite material preferably comprises CaTiO 3 , which may be prepared by combining calcium nitrate (Ca(NO 3 ) 2 ) and tetraisopropyl titanate (Ti(i-C 3 H 7 O) 4 at a ratio of Ca/Ti of 1:1. For example, the calcium nitrate and tetraisopropyl titanate may be dissolved in 2-methoxy ethanol, and a small amount of nitric acid may be added to form a precursor solution which is then dried, pyrolyzed at about 400° C., and then heated in air at about 600 to 800° C.
[0027] Alternatively, CaTiO 3 may be prepared by combining (Ca(NO 3 ) 2 ) with ethyl alcohol, water, and HNO 3 to form a solution. This solution is added dropwise into a solution of (Ti(i-C 3 H 7 O) 4 and ethyl alcohol (at a ratio of Ca/Ti of 1:1). The solution may be evaporated to a dry powder at 200° C. and then calcined at about 600° C. These methods produce a CaTiO 3 powder having a particle size of about 22 to 50 nm.
[0028] The CaTiO 3 perovskite material may be washcoated on a honeycomb substrate using a slurry solution containing the fine perovskite powder. The slurry solution may optionally contain one or more of alumina, zirconia (ZrO 2 ), ceria (CeO 2 ), and Ce—Zr mixed oxide (Ce x Zr 1-x O 2 ). The washcoat loading may vary from about 50 to about 350 g/L.
[0029] The CaTiO 3 washcoated substrate functions to trap sublimed precious metals which may be released from the diesel oxidation catalyst. Again, while not wishing to be limited by any specific theory of operation, it is believed that the trace amounts of platinum group metals released from the DOC become trapped in the lattice structure of the material.
[0030] Referring now to FIG. 1 , one embodiment of the diesel exhaust treatment system 10 is illustrated. As shown in its simplest form, the exhaust treatment system is coupled to an exhaust manifold 12 of a diesel engine and includes a diesel oxidation catalyst 14 which is positioned upstream from an SCR catalyst 18 . The system includes a platinum group metal trap 16 between the DOC and SCR catalyst.
[0031] The diesel oxidation catalyst 14 is coated on a refractory inorganic oxide or ceramic honeycomb substrate as a washcoat at a loading of from about 30 to about 300 g/L and utilizes a catalyst material selected from platinum, palladium, or a combination thereof, and may also contain zeolites. The washcoat may further comprise a binder such as alumina, silica, titania, or zirconia.
[0032] The SCR catalyst 18 comprises a zeolite and a base metal selected from copper and iron. The SCR catalyst washcoat is coated at a loading of from about 30 to about 300 g/L and may be prepared by coating a porous inert substrate with a slurry containing a base metal, zeolite, and binder material such as alumina, silica, titania or zirconia. Alternatively, the base metal/zeolite may be combined with ceramic binders/fibers and extruded into a monolith.
[0033] Referring again to FIG. 1 , the treatment system preferably further includes a reductant delivery system 20 which is coupled to the exhaust manifold directly upstream from the SCR catalyst 18 . A reductant, such as ammonia, aqueous urea or other ammonia-generating compounds, is stored in a storage vessel (not shown) and delivered to the reductant delivery system in metered amounts, typically in the form of a vaporized mixture of the reductant and water. The reductant delivery system includes an injector 22 for injecting an appropriate amount of reductant into the exhaust stream at the appropriate time.
[0034] In another embodiment of the invention illustrated in FIG. 2 , the exhaust treatment system may further optionally include a lean NO x trap (LNT) 26 positioned downstream from the DOC 14 to aid in further reduction of NO x in the exhaust gas. The LNT 26 comprises one or more platinum group metals, and preferably comprises a mixture of platinum, palladium, and rhodium. Preferably, the lean NO x trap has a precious metal loading of from between about 30 to about 300 g/ft 3 . The lean NO x trap further comprises a NO x adsorbent material selected from one or more alkali or alkaline earth metals.
[0035] It should be appreciated that in embodiments which include a lean NO x trap, the use of the reductant delivery system is optional as the lean NO x trap generates ammonia during its operation.
[0036] Also as shown in FIG. 2 , the exhaust treatment system may further include a diesel particulate filter 28 downstream from the SCR catalyst for collecting soot and particulate matter. The diesel particulate filter is preferably a wall flow filter comprising a highly porous filter substrate having a porosity of from about 30 to 80%. The size of the pores preferably range from about 10 to 50 μm. It should be appreciated that the distribution of pore sizes may vary throughout the filter substrate.
[0037] Suitable filter substrates include refractory inorganic oxides or ceramic or metal materials, such as cordierite, mullite, silicon carbide, aluminum titanate, alpha-alumina, silica, and alkali and alkaline earth zirconium phosphates (NZP).
[0038] In an alternative embodiment illustrated in FIG. 3 , the positions of the diesel particulate filter 28 and LNT 26 may be configured such that the DPF 28 is positioned directly downstream from DOC catalyst 14 , and LNT 26 is positioned directly downstream from diesel particulate filter 28 . In yet another alternative embodiment illustrated in FIG. 4 , the positions of the LNT and DPF are reversed.
[0039] In yet another embodiment illustrated in FIG. 5 , the system includes a diesel particulate filter 28 which is positioned between the platinum group metal trap 16 and the SCR catalyst 18 .
[0040] In yet another embodiment illustrated in FIG. 6 , the diesel particulate filter 28 is positioned between the DOC 14 and the trapping device 16 , and the LNT 26 is positioned between the trapping device 16 and the SCR catalyst 18 .
[0041] Referring again to FIG. 1 , during operation, as exhaust gas generated by a diesel engine (not shown) passes through the exhaust gas manifold 12 , it passes through the diesel oxidation catalyst 14 such that conversion of uncombusted HC and CO to H 2 O and CO 2 occurs. The exhaust gas then flows through the platinum group metal trapping device followed by the SCR catalyst. The exhaust gas then flows toward an exhaust gas outlet (not shown).
[0042] As the gas passes through the SCR catalyst 18 , the catalyst removes NO x from the gas stream by selective catalytic reduction with a source of ammonia supplied from the reductant delivery system 20 . Typically, the reductant delivery system 20 utilizes a liquid urea/water solution which is injected downstream from the DOC catalyst 14 at metered intervals. The injected liquid urea/water mixture vaporizes and hydrolyzes to form ammonia. Thus, the NO x component in the gas is converted with selective catalytic reduction of NO x with ammonia to form nitrogen.
[0043] Having described the invention in detail and by reference to preferred embodiments thereof, it will be apparent that modifications and variations are possible without departing from the scope of the invention. | A diesel engine exhaust treatment system and method is provided which includes a platinum group metal trapping device positioned between a diesel oxidation catalyst and an SCR catalyst. The platinum group metal trapping device traps trace amounts of platinum group metals which may be released from the diesel oxidation catalyst during engine operation and prevents them from accumulating on the SCR catalyst, preventing potential contamination of the SCR catalyst as well as ensuring that the performance of the SCR catalyst is uninhibited. | 1 |
BACKGROUND OF THE INVENTION The present invention relates to a vehicular device designed to
operate in enclosed canals. The device includes a main chassis and a swivel head attached by means of a rotatable arm and/or a vertically adjustable boom (manipulator arm) to the face of this main chassis. The device is equipped with wheels both above and below the main chassis.
Preferably, the device is fitted with a head that is suitable for sand blasting the inner surfaces of closed canals. The head can, however, be fitted with an optical appliance, a gamma-ray radiator, a paint spray gun, an air-cleaner nozzle or with similar equipment, where it is important that, during the forward movement of the vehicle, the head maintains a prescribed distance from the inner surfaces of the canal being traversed.
The European Application No. A-99 819 discloses a self-propelled vehicular device which is intended for operation in enclosed canals that cannot be approached by human beings (in this instance, the canals of atomic reactor facilities). The device has a central chassis to which are attached two rollers below and two others above the chassis. The front part of the chassis is bent forward over the lower rollers and thus achieves a detecting position, so that a detector mounted thereon can be moved along the floor of the canal. BY adjusting the angle of the bent chassis and by means of a slight twisting, a certain maneuverability of the detector is possible. The vehicle is maintained in this position by means of two upper rollers, one of which lies b®hind the other along the axis of motion. These upper rollers, which move along the ceiling of the canal, are mounted on two spring-loaded arms interlocked with each other.
The disadvantage of this prior known vehicle is that the central chassis can achieve a particular average distance from the floor of the canal which is determined by the lower rollers. It is true that the upper rollers make possible a degree of control by pressure on the detector. However, allowances for the diameter of the canal cannot generally be made and an adjustment of the main chassis in relation to the center of the canal is not intended or possible.
In order to create a vehicular device for operating in, inspecting, cleaning or sand blasting narrow canal inner surfaces, flat surfaces, ducts or other enclosed cavities which are difficult to pass or to reach, the device must be so designed that the main chassis can be adjusted to the exact midpoint between the upper and lower canal wall. By this is meant for example, canal tubes, aircraft air-intakes, gaseous smoke ducts and such objects whose tubes and gullies display a differing diameter along their length.
Up until now, such canals were cleaned by persons who had to crawl into the canals. Such persons had to be completely enveloped in special suits and supplied from without with air to breathe. This activity was strenuous and posed extraordinary threat to health which could not be reasonably expected of any person over a long Period of time.
SUMMARY OF THE INVENTION
The principal objective of the present invention is to replace the manual sand blasting and similar activities previously carried out by persons by means of a vehicular device that fulfills all the requirements for an even, gentle and effective treatment and cleaning of such surfaces. One especially important objective is that the swivel head, in particular, a sand blasting head, be positioned and moved at a precisely predetermined and exactly maintained distance from the surface to be sand blasted, in order to avoid damage in the form of so-called head crashes. Particularly in the case of aircraft air-intakes, the interior of the canal is formed of extremely thin casing surfaces of only about 0.8 millimeter in thickness.
These objectives, as well as other objectives which will become apparent from the discussion that follows are achieved, according to the present invention, by means of a vehicular device of the aforementioned type which is characterized by having at least two supporting arms attached so as to be able to move in relation to the main chassis. A pair of wheels are attached to each of these, both above and below the main chassis at an equal distance from its midline.
This arrangement of a main chassis between four pairs of wheels insures that the midline of the main chassis is always at exactly the same height between the top and the bottom of the canal. Accordingly, a sand blasting head attached at the height of the main chassis maintains in every direction the same distance from the surface of canal to be cleaned.
Preferably, the supporting arms with the wheels are so suspended that they turn in counter-rotation relative to one another and in relation to the main chassis.
The vehicle is preferably so designed that the main chassis supports at least two supporting arms, each of which has four wheels and that one of the supporting arms lies immediately alongside the attachment of the sand blasting head.
Furthermore, in a preferred embodiment of the invention an exact adjustment of a supporting arm is achieved by means of a power source, the supporting arm being maintained under tension, in relation to the main chassis, at maximal spread. The supporting arm's power source may comprise a torsion spring, a cylindrical spring, any other spring arrangement or even a hydraulic power source.
Instead of wheels, skids or blocks can be employed, whereby the vehicle can be moved passively as well as actively by means of wheels.
In order to keep the work field and the path of the vehicle free of deposited material that is utilized in sand blasting a sweeping device, Preferably a sweeper nozzle or Pair of nozzles, are attached to the front and the back of the vehicle.
For a full understanding of the present invention, reference should now be made to the following detailed description of the preferred embodiment of the invention, and to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of the vehicular device according to a preferred embodiment of the present invention.
FIG. 2 is a lateral view of the device of FIG. 1.
FIG. 3 is a top view of the device of FIG. 1.
FIG. 4 is a detailed view of the power source of the device of FIG. 1.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The vehicular device represented in FIGS. 1 to 4 comprises basically a vehicle 1 with a manipulator arm 2. The length and other dimensions of the vehicle are derived from the dimensions of the canals to be traversed. If the device is utilized, for example, for cleaning aircraft engine air-intakes, the diameter of which changes along its length, the clearance of the rotatable bearing (see below) in the direction of movement is about 75 cm. All other dimensions can accordingly be derived from the illustrated embodiment.
The vehicle 1 consists of a main chassis 3 that, seen from above has the shape of a closed frame. At both outer ends of the main chassis 3 pointing in both directions of motion are attached on both sides rotatable bearings 4 4' and 5 5'. Each of the rotatable bearings 4, 4' and 5, 5' bears at its exact midpoint a supporting arm 6, 6' and 7, 7'. The four supporting arms 6, 6' and 7, 7' bear, in their turn, at each of their ends a wheel 8, 8', 9, 9', 28, 28' and 29, 29', each of which is equipped with a tire of an elastic rubber material. The distance between the wheels attached to a single supporting arms, for example 8 to 8', measured from the opposite crown to crown, is generally greater than the greatest inside diameter of the canal to be cleaned.
The lower ends of the supporting arms 6 and 6', 7 and 7' are connected by means of crossbeams 18 and 19. Furthermore, the axles 20 belonging to the wheels 8, 28 - 8', 28' - 9, 29 - 9', 29' lie parallel to the crossbeams 8 at right angles to the main chassis 3 and provide for reinforcement of the wheel-bearing structure.
Below the main chassis 3 are two terminal boxes 11, 11', which are held in place by means of two curved stays 12, 12'. Attached to these two stays 12, 12' are further two threaded blocks 13, 13' and 14, 14' which project downwards. Through the opening of each of the threaded blocks 13, 13' and 14, 14', respectively, passes a threaded rod 15 which is connected, at its other end, to a cylindrical tension spring 16, 16'. The other end of the tension spring is attached to one of the crossbeams 18 or 19, respectively, whereby each of the two supporting arms belonging to it can be pulled in clockwise or counter-clockwise directions, respectively, until it is arrested by a detent (not represented), as is shown in FIG. 2. A corresponding spring 16' is attached to the rear end of the vehicle and pulls the corresponding supporting arm, respectively 6 or 6', in a clockwise direction. On the other side of the vehicle, corresponding springs work on the supporting arm 6' or 7, as can be seen in a view of the vehicle from above. Thus, the unloaded supporting arms stand at right angles to the horizontal main chassis.
In narrow canals limited by a crown and floor, the supporting arms 6, 6' and 7, 7' are turned in opposite directions when the wheels on their ends, such as 8, 8', come into contact above and below with the inner surface of the canal. Moreover, the main chassis 3 lies exactly in the middle between the upper and the lower wheels so that the distance of the midline of the main chassis to the bottom or the crown of a canal to be traversed remains constant.
The main chassis 3 is traversed in the middle by a central tube 22, which is interrupted at approximately its middle by a branch valve. To keep the FIGS. 2 and 3 simple, this branch valve has not been represented. Furthermore, at the end of the vehicle 1, provision is made for a connection of the central tube 22 to a flexible feeder tube (not shown). The central tube 22 is fed from outside the vehicle with streams of compressed air and a granular blasting material, which are supplied to a blasting device 25 at the end of the manipulator arm 2.
The branch valve 23 is fitted with two steerable branch tubes 27, which lead to two cleaner nozzles 30, 30'; similar cleaner nozzles are also attached to the rear of the vehicle (not visible). The cleaner nozzles 20 serve to clear the work field of left-over blasting material. After completing a predetermined cleaning phase, it is possible to move the blasting material to the end of the canal with the aid of the nozzles and to remove it by known methods. The branch valve is steered by means of a central unit. If needed, compressed air without sand blasting material can be fed to the vehicular device and blown through nozzles 30, 30', by means of this central unit which lies outside the vehicle.
The propulsion of the vehicle 1 is effected via the wheels 9' and 29', which are driven by an electric motor 31 that moves these wheels backwards or forewards at varying speeds, according to the commands. As can be seen in FIG. 4, the electric motor 31 lies on a crossbeam 70 and is supported from below. The motor can be moved to and fro along this crossbeam in the directions of the arrows. Torque transmission is effected my means of a transmission 71 that contains a shaft 32. Depending on the angle, the electric motor of the supporting arm 6, 6', which drives the wheels, shifts its Position on the crossbeam 70 and follows in this manner the movement of the supporting arms and the wheels.
Furthermore, a cable supplying energy and steering signals to the vehicle can be attached to the rear end of the vehicle by means of a plug and socket connection. A steering unit 33 is attached to the main chassis, from which emerge cables and other connections to the relevant part of the device. These functions will be described in detail below. The requisite steering leads are well known in the art so that these need not be described in detail.
The Manipulator Arm
A swivel head 40 for the manipulator arm 2 is attached to the vehicle, namely on the front face 30 of the chassis 3. The swivel head 40 is insulated from a base plate 42 and can be turned about its axis. A flexible tube 43 Pierces the base plate and the swivel head, leading to the blasting nozzle. The swivel head 40 is connected via a drive chain to the output shaft 45' of an electric motor 45, as is shown schematically in FIG. 3. In one variant (cf. FIG. ]) the electric motor 45 lies within the main chassis at right angles to the direction of motion and drives the swivel head 40 via a transmission (not shown here). The direction of rotation of the electric motor can be controlled.
A frontal block 47 is attached to the swivel head. To this block are attached two pairs of parallel sliding bars 48, 48' and 49, 49'. The parallel sliding bars 48, 48' and 49, 49' end at a terminal block 50. The upwards and downwards movement of the terminal block 50 with regard to the frontal block 47 takes place via an electrically-driven, threaded-rod drive 51 with its threaded rod 5Z, which is attached externally at the support points 46 and 46' to the configuration of the parallel sliding bars. By the inwards and outwards movement of the threaded rod 52, the terminal block 50 is moved exactly in the vertical plane, maintaining at the same time its alignment with the main chassis 3, as can be seen in the two maneuver positions represented in FIG. 2. An electric motor 53 is flange-mounted to the underside of the terminal block 50. The motor's output drive shaft 53' is connected to a casing 54 which, in its turn, is linked via a bearing to a sand blasting head 25 comprising a nozzle 55 and a cross-over tube 55'. Two proximity detectors 58, 59, which are arranged at right angles to the direction of motion, are installed pointing downwards in the lower casing wall which lies horizontally 56. Two rubber mounts 60 are fitted in the neighborhood of the proximity detectors 58, 59 as a protection against impact. The proximity detectors 58, 59 emit a signal as soon as the front end of the manipulator arm approaches closer to the wall than a certain preset minimal distance. In such a case, the sand blasting head can be tilted or removed.
Description of Operation
With the supporting arms set in the prescribed Position, the device is put into an opening at the front of a canal to be cleaned. At first, the manipulator arm is fixed in alignment with the main chassis. The device is moved forward to the beginning of the surface to be cleaned. The end of the surface to be cleaned is prolonged by means of an extension tube so that the vehicle can be driven so far along the canal that the sand blasting head 25 can sweep over the entire inner surface of the canal.
It will be appreciated that the vehicle 1 can be driven backwards and forwards within a canal. The manipulator arm 2, which is attached to the front end of the vehicle, can carry out many movements as follows:
Axis 1
By means of the electric motor 45, the front block 47 with its attached parallel sliding bars 48, 48' and 49, 49' can be turned in both directions of rotation through 360 degrees.
Axis 2
With the aid of the electric linear drive via the threaded rod drive 51 with the threaded rod 52, the terminal block 50 can be moved up and down without altering its exact vertical position. In this manner the clearance distances between the blasting nozzle 25 and the surface to be cleaned can be adjusted.
Axis 3
A rotatable module comprising the electric motor 53 and the casing 54 continuously adapts itself automatically and in fine adjustment to the contours of the surface to be cleaned. The blasting nozzle is thus always oriented at an angle of 45 degrees, or some other predetermined angle, with respect to the surface.
Axis 4
The sand blasting head 25 with its nozzle 55 is driven by a pivot drive 57, that moves the nozzle in regular oscillating motions. In this manner, a spray width of, for example, 300 mm can be achieved. The spray width itself is limited by the requirement for evenness and can be preset by means of the adjustable oscillation angle.
The movements about the axes 2 and 3 of the aforementioned motion systems function automatically; they are controlled by self-propelled steering equipment. This is the purpose of the proximity detectors 58, 59 attached to casing 54.
After switching on, the device lowers the manipulator arm 2 by means of the movement of the threated rod drive slowly downwards until the minimal clearance of a proximity detector from the surface has been exceeded. As soon as this proximity detector (58 or 59) emits a signal, the threaded rod drive and the rotatable module - that is, the electric motor 53--begins to rotate the casing with the proximity detectors. The rotation is always such that the neighboring proximity detector is moved towards the surface. To each of the proximity detectors is thus allocated a particular direction of rotation of the electric motor 53. When the second proximity detector responds, the manipulator arm is withdrawn until one of the proximity detectors ceases to emit a signal. Subsequently, a rotational movement follows in the direction in which the other proximity detector again responds. Should both detectors respond simultaneously, the manipulator arm 2 moves upwards and increases the distance between the nozzle 25 and the surface again. By means of this regulation via two proximity detectors 58 and 59, it is possible for the manipulator arm to follow the surface exactly and to allow a very precise sand blasting.
By means of the constant undulating movement of the nozzle in the bearing 54, a strip about 300 mm wide is carefully cleaned.
Having driven along and cleaned this strip, the vehicle eventually reaches the end of the canal. BY regulating the rotatable section by means of the electric motor 45, the manipulator arm is rotated. The vehicle travels again to the beginning of the canal strip to be cleaned and senses independently the vault of the canal. At the same time, the oscillation width can, according to such requirements as paint thickness or fragility, be adjusted from the outset to differing rotational angles. During the following passage, the rotational angle is so altered that another strip is sand blasted.
Various granulates or other materials known in the art can be utilized in the sand blasting.
It will be apparent that with this tool it is possible to clean a canal surface without causing damage to the most difficult vaultings. Attention is also drawn to the fact that parts of the device projecting outwards that could possibly come into contact with the inner walls of a canal are preferably covered with a foam-upholstery material.
Instead of a sand blasting head, optical equipment, a gamma radiation element, a paint sprayer, an air-cleaning nozzle or similar such tools can be employed, in all instances in which it is necessary that these units maintain in operation a constant clearance from a particular surface.
There has thus been shown and described a novel vehicular device designed to operate in enclosed canals which fulfills all the objects and advantages sough therefor. Many changes, modifications, variations and other uses and applications of the subject invention will, however, become apparent to those skilled in the art after considering this specification and the accompanying drawings which disclose the preferred embodiment thereof. All such changes, modifications, variations and other uses and applications which do not depart from the spirit and scope of the invention are deemed to be covered by the invention which is limited only by the claims which follow. | A vehicular device designed to operate in enclosed canals includes a swivel head (25) which is connected by means of a rotatable and/or vertically adjustable boom (manipulator arm) (2) to the front end of a main chassis (3). The main chassis is fitted with rotatable supporting arms (6, 7; 6',7') to which are attached, both above and below and equidistant to the midline of the main chassis, pairs of wheels (8, 8'; 9, 9'; 28, 28', 29, 29'). The supporting arm or arms are maintained by means of a power source (16, 16') in a position of maximal spread in relation to the main chassis. | 4 |
RELATED APPLICATIONS
[0001] This patent application claims priority from U.S. Provisional patent application Serial No. 60/183,677, entitled Method and Apparatus for Graphical Representation of Real-Time Data, filed Feb. 18, 2000.
FIELD OF THE INVENTION
[0002] The invention is in the field of software for processing and representing real-time data.
BACKGROUND OF THE DISCLOSURE
[0003] For many processes that involve constantly changing data, it is desirable for a user of the data to be able to have access to an understandable version of a current state of critical data. This is particularly true when the user must make a decision based upon real-time data that will not remain static for very long. Increasingly, interactive processes are conducted by multiple participants via some electronic network. Each participant may at any time take an action that changes the critical data of the process. An example of such a process is an auction that is conducted via the Internet. Participants are typically multiple buyers and sellers who may change ask prices and bid prices at any time.
[0004] Currently, auctions that are conducted in a networked environment, such as the Internet, are limited in the types of information provided to auction participants. An auction participant generally lists a product or service, or solicits a product or service, on an auction site. Participants then bid upon the product or service of interest. Generally, the listing of a product or service, either offered or solicited, is placed in a standard hypertext markup language (HTML) text listing at a particular auction web site. Auction participants may submit a bid or solicit offers, typically via electronic mail, for a particular product or service. In conventional electronic auctions, the auction participants do not have access to auction information other than the current asking price of the offered or solicited product or service. In conventional electronic auctions, participants are generally not aware of the dynamics of a current active auction, such as: data on other offers or bids from other auction participants; whether a particular auction transaction has been completed; how the auction participant's offers or bids compare with those of other auction participants; and a variety of other changing auction data.
[0005] The typical auction environment has another disadvantage, namely, general latency problems with updating and processing bids and offers. Commonly, in current auction systems, a series of different bids or offers sent via electronic mail are received by a particular auction system but are not expeditiously processed. As a result, some auction participants are excluded from effectively participating in particular auctions, or their participation is delayed. Current electronic auctions, therefore, do not provide participants with important data regarding current auction dynamics.
SUMMARY OF THE DISCLOSURE
[0006] Embodiments of the present invention include an interactive user interface for effecting and monitoring real-time processes. In one embodiment the user interface includes software instructions that cause an operating system to periodically collect real-time data regarding a real-time process. The real-time data is used to update a display with a graphical representation of the current state of the process. Multiple objects on the display represent, for example, buyers and sellers. The objects on the display convey various pieces of changing information, such as: the number of items offered by a seller; the relative magnitude of a price offered by a buyer; how close a bid price and an ask price are; how long a bid or ask has been outstanding; when a bid or ask has been updated; and when a transaction is consummated. The information is instantaneously conveyed in a variety of ways, including: color of objects; relative positions of objects; and position of objects relative to a point on the display. In one embodiment, a server is periodically polled for real-time data with which to update the display. The update frequency can be controlled by a user. The type of data updated can also be controlled by a user. The user interface is also interactive; for example a process participant can change the real-time data by manipulating objects on the display.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] [0007]FIG. 1 shows an embodiment of a user interface display.
[0008] [0008]FIG. 2 shows an embodiment of a user interface display.
[0009] [0009]FIG. 3 shows an embodiment of a user interface display.
[0010] [0010]FIG. 4 shows an embodiment of a user interface display.
[0011] [0011]FIG. 5 shows an embodiment of a user interface display.
[0012] [0012]FIG. 6 shows an embodiment of a user interface display.
[0013] [0013]FIG. 7 shows an embodiment of a user interface display.
[0014] [0014]FIG. 8 shows an embodiment of a user interface display.
[0015] [0015]FIG. 9 shows an embodiment of a user interface display.
[0016] [0016]FIG. 10 shows an embodiment of a user interface display.
[0017] [0017]FIG. 11 shows an embodiment of a user interface display.
[0018] [0018]FIG. 12 shows an embodiment of a user interface display.
[0019] [0019]FIG. 13 shows an embodiment of a user interface display.
[0020] [0020]FIG. 14 shows an embodiment of a user interface display.
[0021] [0021]FIG. 15 shows an embodiment of a user interface display.
[0022] [0022]FIG. 16 shows an embodiment of a user interface display.
[0023] [0023]FIG. 17 shows an embodiment of a user interface display operating as a banner on an Internet web page.
[0024] [0024]FIG. 18 shows an embodiment of a user interface display.
DETAILED DESCRIPTION
[0025] An interactive user interface for effecting and monitoring real-time processes is described. The user interface includes software instructions that cause real-time data about the process to be collected and graphical information about the current state of the process to be displayed to a user or participant. The display can be part of a client computer on a network such as the Internet. The real-time data is changeable by a participant who manipulates the graphical display. Participating in the process is therefore much easier and faster than previously possible. The user interface provides an intuitive, interactive real-time environment for participants in any data-intensive process. In one embodiment, the user interface provides an intuitive, interactive real-time environment for participants in a network electronic auction.
[0026] In one embodiment, the user interface (“UI”) includes template-generated hypertext markup language (HTML) pages and dynamic content. The dynamic content could be in any form, such as Java and DHTML. One component of the UI is an interactive graphical representation (“display”) 100 of real-time data that is shown in FIG. 1. The display 100 typically appears on a display device of a user or participant. The display 100 conveys information and is also a control device in that it accepts participant input directly through manipulation of the objects on the display 100 . A single seller or buyer is represented by the large object 102 in the center of the display 100 , and individual buyers or sellers are represented by various buyer objects and seller objects around the object 102 .
[0027] The display changes as the real-time auction data changes. For example, as shown in display 200 in FIG. 2, as the prices offered by the buyers (in one particular marketplace) more closely approach the asking price of the seller represented by seller object 202 , the pertinent buyer objects move proportionally on the display 200 . In display 300 of FIG. 3, as the prices offered by the buyers (in one particular marketplace) diverge from the asking price of the seller represented by seller object 202 , the pertinent buyer objects move proportionally on the display 300 . The display functions symmetrically with respect to buyers and sellers; that is, either a seller can be represented in the center, surrounded by many buyers, or a buyer can be depicted surrounded by many sellers. As will be further described below, the display is also used to represent many buyers and sellers at the same time. Additionally, any objects other than circles could be used to represent the buyers and sellers.
[0028] The user interface includes many features, some of which will be discussed with reference to further figures. FIG. 4 illustrates how the position of objects relative to each other represents the degree to which transactions are close to consummation. Object positions are updated dynamically, and the distance between objects decreases as a transaction comes closer to consummation. This gives participants a clear impression of movement in the market. No participant action is required to watch updated information. In display 400 , the transaction represented by “A” is closer to consummation than the transaction represented by “B”. A transaction takes place when the distance between a buyer object and seller object becomes zero. On display 400 , a buyer object would travel to the center and touch seller object 402 when a transaction between the two is consummated. The movement of the buyer objects and seller objects on the display 400 produces an “at-a-glance” knowledge of market changes and conditions.
[0029] Distance as a representation of price or “score” produced by a multiparametric weighting can be represented on a logarithmic scale in one embodiment. This means that movements in the market are accelerated near the center. These accelerated movements produce an exaggerated representation of market conditions near the consummation of a transaction. In display 500 of FIG. 5, the grid lines 502 , 504 and 506 are placed at ¼ of the asking price, ½ of the asking price, and ¾ of the asking price, respectively. The lines 502 , 504 and 506 provide a yet more specific, immediate visual quantification of the progress of an offer. These grid lines could be given other value representations (e.g. ⅓, ½, {fraction (2/3 )}) if desired. In addition, the grid lines do not necessarily represent a percentage of an asking price; the lines can also represent the degree to which a proposal by a central buyer is met, in the case where the central object is a buyer. In that case, the grid lines 502 , 504 and 506 would represent “ask ¼ of bid,” “ask ½ of bid,” etc. In other embodiments, distance is measured using a linear or other scale in place of the logarithmic scale.
[0030] Another feature of the display, illustrated in the display 600 of FIG. 6, is that the size of an object represents the number of items held or desired by a seller or buyer. Object “B” represents an offer for a greater number of items, while object “A” represents an offer for a smaller number of items because object B is larger than object A.
[0031] Color is also used to convey information. As an example: asks are colored orange; bids are colored blue; objects representing particular buyers or sellers who are using the user interface are colored red; updated offers are flashed yellow; and when a deal is consummated objects representing the participants in the deal are briefly colored purple. The flashing of updated offers in yellow and consummated transactions in purple gives an immediate visual impression of activity in the market.
[0032] Sound is used to convey information as well. When a transaction is consummated, a sound is produced. When new offers are entered into the user interface, a different sound is generated.
[0033] As shown in FIG. 7, the position of an offer on the display 700 as measured in radians or degrees from a reference point is used to convey information. The information conveyed includes the time a particular buyer or seller entered the auction. For example, offerors enter the auction at the 360° position on the display 700 and travel clockwise around the display as time progresses. Therefore, offer B has been in the auction for a longer period of time than offer A.
[0034] Embodiments of the user interface include an interactive display as shown in FIGS. 8 and 9. Buyers and sellers can manipulate their respective buyer objects and seller objects on the display to change the real-time auction data. In one embodiment, objects on the display are manipulated with an input device such as a mouse. For example, when a particular offer is selected and moved on the display, a corresponding price change (or “score” change, in a multi-criteria auction) is automatically entered for that offer. That is, the real-time data used by the system is changed to reflect the new price or score. This is a much easier and faster method of entering or changing an offer than conventional keyboard-based or template-based input systems.
[0035] The display 800 shows an offer being increased by dragging a corresponding object closer to the center of the display 800 . The display 900 shows an offer being decreased by dragging a corresponding object away from the center of the display 900 . In addition to the display, “price” button B and “confirm order” button C display the current offer price and allow the participant to confirm an order, respectively. As the object is dragged through the display field, the price at B is dynamically updated. The method described here (with a dynamically varying price display and a confirmation button) is one possible implementation of this system. For example, the confirmation button can be eliminated. After an offer is confirmed, the updated offer is sent to an auction engine.
[0036] Another feature of the user interface is that a user can learn more about an individual offer, such as quantity, price, and other information, with a “mouse over” using an arrow pointer or other similar technique.
[0037] As illustrated in FIG. 10, offers can be graphically entered and placed in the display 1000 field. Offers can be removed from the display 1000 field in a similar fashion. The price is dynamically updated at B and the participant confirms at C.
[0038] As illustrated in FIG. 11, offers can be dragged to the center of the display 1100 for consummation. The price is dynamically updated at B and the participant confirms at C.
[0039] In one embodiment, a buyer or seller in the center can capture multiple offers at once through a “pull” feature. This is illustrated in FIGS. 12 and 13. For example, as a seller whose object is in the center of the display 1200 clicks in the center and drags outward from A to B, a dynamic calculation is made as to the number of offers inside the generated “ring” and how much money (in the case of offers defined by price) would be received by the seller if all the offers in the ring were accepted. Approximately nine offers have been captured inside the ring on the display 1200 . The quantity and price are updated at C and D, and the participant can confirm at E. In FIG. 13, approximately twenty-four offers have been captured in display 1300 . This interactive technique allows quick and intuitive cash and unit management for buyers and sellers. Offers inside the ring may represent different quantities, and this is included in the quantity and price calculations.
[0040] Referring to FIGS. 14 and 15, a buyer or seller whose object is in the center can dynamically vary his or her offering price by “grabbing” the display field and moving it closer or farther from the center. The display 1400 field is being dragged away from the center, resulting in a higher offer price. The display 1500 field is being dragged closer to the center, resulting in a lower offer price.
[0041] The user interface can be generalized to show many buyers and sellers at the same time, as shown in FIG. 16. Interactive features such as those previously described are implemented for a double display 1600 . In one embodiment, the A side of the display 1600 represents buyers and the B side represents sellers. Transactions are consummated in the center C.
[0042] The user interface can be displayed over the Internet or any other network as a banner advertisement, which will give users the opportunity to see markets in a live fashion throughout the world wide web, as shown in FIG. 17. Users can also interact with the display 1700 , through for example, DHTML and Java, or DHTML and JavaScript. Many other implementations are possible.
[0043] One embodiment of a user interface that includes multiple buyers and multiple sellers is shown in FIG. 18. The display 1800 has a “butterfly” design that separates the buyers and sellers. Two radial lines define an area occupied by either buyer objects or seller objects. In the display 1800 , area A contains seller objects, and area B contains buyer objects. The remaining areas, as illustrated by C, are blank.
[0044] The manner in which the real-time data is collected and processed is variable. For example, in one embodiment, the user interface provides updates to web browsers in real time. To accomplish this, the display, as a Java applet in a browser, “polls back” to an originating server on a timed basis (e.g. once a second) to receive real-time data updates. These data updates allow the display to reflect the relative changes in offer positions. In some circumstances, this technique can result in a number and/or frequency of server requests that becomes burdensome to the server. Other embodiments help reduce the number of server requests while still providing pertinent real-time information graphically.
[0045] One of the alternate embodiments allows a participant to specify that the data associated with a subset of the objects displayed will be updated on a relatively more frequent basis, while the remainder are updated relatively less frequently. For example, suppose that there are M current offers (bids and asks) being displayed, and no differentiation is made as to data to be updated. In the previously described embodiment, each time an object is moved, the display polls back to the originating server with requests for M pieces of data to be displayed. In a first alternative embodiment, however, the user can specify that only N offers (where N is less than M) will be updated in real time, while the remaining M-N offers will receive updates on a less frequent basis. Generally, the N offers that are updated will be the highest bids and the lowest asks, or those most likely to result in a transaction at any particular time. As an actual example, if fifty offers are displayed, the user might specify that twenty of those offer be updated in real-time, or about once per second. The frequency with which the remaining thirty offers are updated can be specified as, for example, one fifth or less of the original frequency, that is, once every five seconds or less often. The frequency specified can be any frequency that is less than the original frequency. The frequency is typically chosen to optimize the reduction of server requests and the amount of data transferred per request.
[0046] A second alternative embodiment provides another way to reduce the number of requests to the server. In this embodiment, the display is initially set to refresh its data from the server at a specified frequency, for example once per second. The user interface then measures the rate of data change by determining an amount of change in a current set of data received and comparing it to the amount of change in a data set previously received. If the rate of data change is low, the user interface increases its refresh interval, for example from one second to two seconds. Conversely, if the rate of change is high, the user interface reduces its refresh interval. The user can set the upper and lower bounds for this procedure. Thus, a user might specify that the display will refresh no more often than once a second, but no less frequently than once every five minutes. In this way, an optimal refresh rate can be determined and the server is only heavily loaded when the rate of data change is high. In addition, the user experience is relatively unaffected, because the data refresh period is lengthened only when there are relatively few changes in the data to be observed.
[0047] The invention has been described with reference to specific examples. Various modification to the example embodiments may be made by one skilled in the art without departing from the scope of the invention, which is defined by the following claims. | A method for effecting and monitoring a real-time, multi-participant process via a network. In one embodiment, the method includes periodically collecting real-time data regarding the real-time process, and periodically updating a display comprising a graphical representation of a current state of the process using the real-time data. The method further includes receiving user inputs via the display, wherein the user inputs include changes to the real-time data, and in response to the user inputs, updating the display to reflect the changes to the real-time data. | 6 |
This application is a continuation of application Ser. No. 07/407,359, filed Sep. 14, 1989, now abandoned.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a navigation system for vehicles such as automobiles, and more particularly to an information processing system and method which are well suited to estimate the position of a vehicle at high precision by the use of map data.
2. Description of the Prior Art
As stated in, for example, "Nikkei Electronics" dated Nov. 16, 1987, pp. 119-130, a prior-art on-board navigation system for a land surface vehicle such as automobile employs a method wherein the position of the vehicle itself, which is estimated by the use of a travel distance detected by a car speed sensor mounted on the vehicle, as well as a current azimuth angle obtained from a steering angle detected by a steering angle sensor or an attitude angle detected by a magnetic sensor similarly mounted, is displayed in superposition on map data.
There is also a method wherein, in order to heighten the estimation accuracy of the position of the vehicle itself, a receiver in a GPS (Global Positioning System) or a receiver for location beacons (sign posts), which are radio beacons installed on roads for transmitting the absolute positional information items thereof, is mounted, and the received information of the system or beacon is used in combination with the data of the aforementioned travel distance or current azimuth angle.
Further, there has been known a method wherein, in order to prevent an estimated current position from missing a road on a map because of an error, an estimative current position to be displayed is corrected onto the road by the use of the positional information of the road of map data. An example of the method is discussed in the official gazette of Japanese Patent Application Laid-open No. 56910/1986.
The first prior-art technique mentioned above is such that, on the basis of the initial position of the vehicle at the start of the travel of the vehicle or at the start of the display of the position of the vehicle, the travel distance and the current azimuth angle detected every moment are integrated to evaluate the current position at each of later points of time. Therefore, it has the disadvantage that the errors of the initial position, travel distance and current azimuth angle diverge accumulatively.
Since the second prior-art technique can directly estimate the position of the vehicle by the use of the GPS or the location beacons, a positional error does not diverge with time. Nevertheless, an error of several tens of meters to several hundred meters remains.
With the two prior-art techniques, accordingly, there has been the problem that, when the estimated current position is displayed in superposition on the map, the displayed position misses the road in spite of the traveling of the vehicle on the road.
In the third prior-art technique, the probability density of the current position at every moment is computed, and it is compared with a road position in the map data. When a place on the road whose probability exceed a certain fixed threshold value has been detected, it is displayed as being the current position. Herein, the probability density is assumed to be of a Gaussian distribution, and it is approximated with a small number of parameters. This method has had the problem that actually the probability density falls into a shape different from the Gaussian distribution on account of speed regulation, diversion, etc., so the estimation does not become optimal. Another problem is that, in someways of selecting the threshold value, the current position is forcibly displayed on the road in a case where the vehicle actually misses the road on which the current position is displayed and where it lies at a position, such as a back street, which is not contained in the road information of the map data.
Meanwhile, the positional accuracy of a vehicle has been enhanced by the following method: Road map data recorded on a CD-ROM is displayed on the CRT of a dashboard, and the start point of the vehicle is input on the map of the CRT by a cursor when the vehicle starts traveling. Then, the current position is displayed on the map of the CRT on the basis of a car speed and information on a traveling direction from a terrestrial magnetism sensor. In particular, an estimated trajectory is compared with a route pattern on the map, and the positional information and the map pattern are checked up at the intersection of roads or the bending point of a road, so as to estimate the position of the vehicle believed correct.
In this case, however, the errors of the azimuth and the car speed are corrected only at the travel of the vehicle through the featuring point and on each occasion. Accordingly, there has not been considered the problem that, once the vehicle has entered an erroneous route, the correction fails.
Further, the above method considers only the local correction on the error of the estimative current position attributed to the accumulation of the errors of the preceding azimuths and car speeds. As another problem, accordingly, there has been such a possibility that the estimated current position on the CRT will miss a road, or that the vehicle will enter a road not leading to a destination, while resorting to the estimated positional information which is different from the actual current position.
SUMMARY OF THE INVENTION
An object of the present invention is to provide a system and a method which heighten the estimation accuracy of the current position of a vehicle so as to present a display conforming to a road map.
Another object of the present invention is to provide an on-board navigation system in which an estimated trajectory based on information items from several sensors is compared with the shape of a road in a memory device such as CD-ROM, thereby making it possible to sequentially correct an estimative current position and simultaneously to evaluate the certainty of estimation.
In order to accomplish the objects, the present invention is constructed as follows:
A navigation system using map data, which has a first sensor for detecting a travel distance of a vehicle and/or a second sensor for detecting a current azimuth, a memory for storing the map data, and a data processor, is characterized in that at least one of the travel distance and the current azimuth is detected by at least one of said first and second sensors, and that quantization units, each of which permits execution of a probability calculation determined by a detection accuracy of said sensor and quantization of said map data, are set, whereupon as regards each of said quantization units, a probability density of a current position is calculated from said map data and said at least one of the detected values by said data processor.
Besides, a navigation system using map data, which has a speed sensor, a current azimuth sensor, a memory for storing the road map data, and a processor, is characterized in that a speed and an azimuth of a vehicle are respectively sensed by said speed sensor and said current azimuth sensor, that estimative current positions of the vehicle are estimated according to DP matching calculations on the basis of the sensed speed and azimuth and the map data, that coordinates of a plurality of places on roads as the estimated current positions are stored together with uncertainties (costs) corresponding to the respective estimated current positions, and that estimative current positions at a next time and uncertainties corresponding to them are evaluated from a speed and an azimuth sensed and the road map data on the basis of the estimated current positions and the uncertainties thereof, whereby the estimative current positions are iteratively updated.
Now, the operating principles and functions of the present invention will be elucidated before the description of embodiments.
First, in a case where, regarding the calculation units of the map data, current position probability densities are evaluated in respective units obtained by quantizing the calculation units, the following functions are attained:
The data processor evaluates the location probability of the vehicle in each place, namely, the probability density of the current position every moment on the basis of the detected values of the travel distance and traveling direction and the map data. A point at which the probability takes the maximum value, is set as the estimative value of the current position. Here, a posterior conditional probability is calculated using the prior probability of the current position which takes the large value on a road given by the map data and small values in the other places, so that the estimative value of the current position does not err and miss the road badly. Moreover, when the respective positions are displayed in superposition of the map data in, for example, different colors in accordance with the probability densities, the user of the navigation system can know the estimated situation of the current positions more precisely every moment, and the risk at which the user is puzzled by an estimation error can be made less than with a method wherein only one current position is displayed.
Here, an estimation system for use in the present invention will be described.
Let's consider a stochastic process expressed by the following state equation which is obtained through sampling at suitable time intervals:
x.sub.i +1=f.sub.i (x.sub.i)+d.sub.i ( 1)
(i=0, 1, . . . )
where x indicates a state vector of order n, f a vector function of order n, and d i an external force vector of order n. Letter "i" is a suffix denotative of time. It is assumed that the probability density p(x 0 ) of x 0 is given as prior information. On the other hand, it is assumed that observation data on an external force as expressed by the following observation equation is obtained every time:
y.sub.i =d.sub.i +G.sub.i w.sub.i ( 2)
(i=0, 1, . . . )
where y denotes an observation vector of order n, and w denotes a white noise vector of order n, the probability density p(w) of which is assumed to be given.
Further, it is assumed that a conditional probability density p(x i+1 |x i ) (i=0, 1, . . . ) is given as a restrictive condition. On this occasion, as the first system, there is considered the estimation problem of finding the state x N which maximizes a posterior conditional probability:
P(x.sub.N |y.sub.0, . . . , y.sub.N-1) (3)
when the observation data y i (i=0, . . . , N-1) is given.
The solution of this problem is given as stated below. On the basis of the models of Eqs. (1) and (2), Eq. (3) is expressed as follows in accordance with Bayes' rule: ##EQU1## Here, for N=1, the following holds:
P(x.sub.1 |y.sub.0) =∫p(y.sub.0 |x.sub.0, x.sub.1)·p(x.sub.1 |x.sub.0)/P(y.sub.0)·p(x.sub.0) ·dx.sub.0 ( 5)
Accordingly, p(x 1 |y 0 ) can be obtained owing to Eq. (5) on the basis of the models of Eqs. (1) and (2), and p(x N |y 0 , . . . , y N-1 ) can be obtained in the ascending series of N owing to Eq. (4) for N≧2. Thus, the estimated values of the desired state vectors are obtained as the states x N which maximize the aforementioned probability for the respective N values. The above is the solution of the estimation problem based on the first system.
Next, as the second system, there is considered the estimation problem of finding the state series x i (i=0, 1, . . . , N) which maximizes a posterior conditional probability:
P(x.sub.0,x.sub.1, . . . , x.sub.N |Y.sub.0, . . . , y.sub.N-1) (6)
when the observation data y i (i=0, . . . , N-1) is similarly given.
The solution of this problem is given as stated below. On the basis of the models of Eqs. (1) and (2), Eq. (6) is expressed as follows in accordance with Bayes' rule: ##EQU2## Both the sides of Eq. (7) are transformed into:
I.sub.N =I.sub.N-1 ×C(X.sub.N, X.sub.N-1) (8)
Here, ##EQU3## Although the problem is to find the states x 0 , x 1 , . . . and x N maximizing I N , the following maximum value J N (x N ) with the state x N assumed given shall be considered here:
J.sub.N (x.sub.N)=max I.sub.N (x.sub.N) (9)
From Eq. (8), the following is obtained: ##EQU4## holds. J 1 (x 1 ) can be computed by Eq. (11) on the basis of the models of Eqs. (1) and (2), and C(x N , x N-1 ) can be computed by Eq. (8), so that J N (x N ) is evaluated in the ascending series of N from N=2 by Eq. (10).
Assuming that the maximum value J N (x N ) has been obtained in this way, x N maximizing it becomes the state x N among the desired states x 0 , x 1 , . . . and x N maximizing the probability I N , because Eq. (9) is transformed as follows: ##EQU5## The states x 1 , . . . and x N-1 are obtained by solving Eq. (10) in the descending series of N on the basis of this state x N , and the last state x 0 is obtained from Eq. (11). The above is the solution of the estimation problem based on the second system. Incidentally, the posterior conditional probability (6) on this occasion is given by:
P(x.sub.0,x.sub.1, . . . , x.sub.N |y.sub.i, . . . , y.sub.N)=I.sub.N ( 13)
in view of Eq. (8).
According to the above procedure, the probability density is permitted to be precisely computed even when it is not in the shape of the Gaussian distribution.
Secondly, as to a case where an estimated current position of low uncertainty (cost) is found from among the plurality of estimated current positions, the operating principles and the functions will be described.
Let's consider that a running trajectory estimated from only road data and on-board sensor data as shown in FIG. 23 is matched as the whole trajectory from a start point A to the point of the current time B. The running trajectory and the road data of candidate routes to-be-matched are expressed by the values θ v (j) and θ r (j) of the running azimuths of unit distances ΔS along the respective routes from the start point A. It is assumed that j=N holds at the point B.
Now, the matching between the running trajectory AB and the candidate route is executed by minimizing the following matching cost formula: ##EQU6## The second term of the right-hand side of Eq. (14) denotes a cost concerning the transformation of the running trajectory AB, and the first term denotes the degree of disagreement of the transformed route. Letter W indicates the weighting of both the costs, and the degree at which the transformation is allowed heightens as the value W is smaller. Eq. (14) supposes a case where random errors are superposed on the speed data and the running azimuth data which are used for evaluating the running trajectory, and where the error of a travel or running distance is the accumulation of the speed errors. A trajectory transformation data sequence {ε j *} minimizing Eq. (14) gives how to transform the running trajectory AB for the purpose of the matching, and the minimum value J * gives a matching error which remains even in the optimal matching. Besides, where the estimative position B at the current time ought to lie on a road is known from the trajectory transformation data sequence {ε J *} which gives the optimal matching, and the estimate current position B which misses the road can be corrected onto the road B' in consideration of the whole route.
In a case where the minimum value J * of the matching cost is equal to or greater than a predetermined value, it can be judged that the matching itself is unreasonable. Moreover, when matching costs which are not the minimum but which are close to the minimum are set as J 1 , J 2 , . . . in the order of smaller values and trajectory transformation data sequences corresponding to them are set as {ε j 1 }, {ε j 2 }, . . . , quasi-optimal matching operations can be a together with matching degrees.
In the above, there has been considered the case where the running trajectory is matched with the single road having no branch. In contrast, in a case where branches such as the intersection of roads are contained in the road data, all the routes along which the vehicle can run are picked up, whereupon the result of the single optimal matching determined for all the candidate routes and the results of a plurality of quasi-optimal matching operations are obtained.
The end point B of the running trajectory stretches with the running of the vehicle, and the distance along the trajectory increases from N to N+1, . . . . Also, the optimal trajectory transformation {ε j * } minimizing the matching cost of Eq. (14) is computed every moment with the running of the vehicle, and the corrected (displayed) current position B' changes every moment. However, the trajectory transformation {ε j *}:j= 1-N up to the current position of j=N does not always give the preceding N terms of the optimal transformation {ε j * }:j=1-M concerning the later position of j=M (M>N). That is, even when the compensation of the position up to a certain point of time is erroneous, the optimal matching of the whole route including the subsequent trajectory is found out, whereby the error might be recovered. In particular, when the matching cost of Eq. (14) is decomposed depending upon the position j along each road as ##EQU7## and the matching cost J j * of each position is decided, it is possible to judge the occurrences of the following on the running route:
(i) Running deviating from road data
(ii) Error of on-board sensor data
Meanwhile, the optimal matching which minimizes Eq. (14) can be attained by DP (Dynamic Programming). As illustrated in FIG. 24(a), the positions j along the trajectory and the positions i along the road data are respectively taken on the axes of abscissas and ordinates, thereby to consider lattice points. As indicated in the figure, possible paths are drawn in three directions from each lattice point and are respectively given costs W, O and W, and a cost {θ v (i)-θ r (j)} 2 is also afforded onto the lattice point. Letting J * (i, j) denote that one of the operations of matching the position j of the trajectory to the position i of the road data which minimizes the cost of Eq. (14), it is the minimum value of the summation of the costs on the paths in the possible routes from the origin to the lattice point (i, j) in FIG. 24(a) and the cost on the lattice point. ε j denotes any of -1, 0 and 1. The equation of the DP becomes: ##EQU8## Incidentally, the optimal matching cost J * at the point j is i min J * (i, j). In the DP calculations, the minimum values J * (i, j) are obtained successively from the origin J * (0, 0)=0 in accordance with Eq. (16).
Assuming now that the running distance of the vehicle is j=N and that j * (i, N) has been obtained, j * (i, N+1) at the next vehicular position j=N+1 is evaluated by executing only the calculation of the final stage concerning j=N+1 in the DP calculations. Thus, the DP calculations can be realized by iterative processing conformed to the running of the vehicle. It is repeatedly stated that the estimated (compensated) vehicular position at j=N is found as the position i * (N) on a road minimizing J * (i, N).
Meanwhile, the above calculations spread radiately on a lattice in FIG. 24(b) as the vehicle runs, and the number of points at which J * (i, j) is to be computed increases in proportion to an increase in the positions j (the proceeding of the vehicle). Therefore, when the cost J * (i, j) has exceeded a threshold value, the calculation of the route passing the corresponding lattice point is stopped thenceforth so as to omit wasteful calculations and to hold the amount of calculations substantially constant at any time. Accordingly, the start point of the cost computation, namely, the start point of the trajectory to be matched is also shifted in accordance with the running of the vehicle so as to keep a trajectory length constant, and the threshold value for deciding the cost J * (i, j) is also kept at a constant value.
In the above way, the vehicular position can be compensated by optimally matching the whole trajectory to the road data, and the calculations for finding the optimal matching can be executed by the iterative processing of the DP conformed to the running of the vehicle. Although Eq. (14) has been indicated as an example of the matching cost formula on which the DP calculations are based, the present invention is not restricted to this equation.
In each of the calculating systems, the positional quantization units with which the probability or cost of the estimative vehicular position is computed are determined by the detection accuracies of the detection means and the quantization of the map data (and the processing speed of the calculation). Here, points on the two-dimensional space of the land surface are quantized in the "probability" system, while points on road segments are quantized in the "DP" system. Besides, positional quantization units in the case of presenting the estimated result of the vehicular position to the user by image display or any other means need not always agree with the quantization units for the computation.
The foregoing and other objects, advantages, manner of operation and novel features of the present invention will be understood from the following detailed description when read in connection with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a general block diagram of an embodiment of an on-board navigation system according to the present invention;
FIG. 2 is a diagram showing the display example of a map and a vehicular position;
FIG. 3 is a diagram showing the probability density of the vehicular position;
FIG. 4 is a diagram showing the geometrical relationship of a running route;
FIG. 5 is a diagram showing the initial value of the probability density in a driveway;
FIG. 6 is a diagram showing the initial value of the probability density in any other road;
FIG. 7 is a diagram showing the conditioned probability density of the vehicular position on the driveway;
FIG. 8 is a diagram showing the conditioned probability density of the vehicular position in the presence of the possibility of running which misses a road;
FIG. 9 is a diagram showing the conditioned probability density of the vehicular position which lies outside the road;
FIG. 10 is a diagram showing a procedure for estimating the probability density of the vehicular position;
FIG. 11 is a diagram showing an estimated running route;
FIG. 12 is a diagram showing a procedure for estimating the probability density of the vehicular position in another embodiment;
FIG. 13 is a diagram showing the format of node data in map data;
FIG. 14 is a diagram showing the format of link data in the map data;
FIG. 15 is a general block diagram of an embodiment of a vehicular location system according to the present invention;
FIG. 16 is a block diagram of on-board devices;
FIG. 17 is a block diagram of a center device;
FIG. 18 is a block diagram of on-board devices in another embodiment of the vehicular location system;
FIG. 19 is a block diagram of a center device in the second embodiment;
FIG. 20 is a diagram showing the probability density of a vehicular position in a driveway;
FIG. 21 is a diagram showing the probability density of the vehicular position in an urban district;
FIG. 22 is a block diagram of an embodiment of an on-board navigation system according to the present invention;
FIG. 23 is a diagram for explaining map data and a trajectory;
FIG. 24(a) is a diagram for explaining DP matching, while FIG. 24(b) is a diagram for explaining the stop of DP calculations as based on the check of a matching cost; and
FIGS. 25(a) and 25(b) are diagrams showing map data and the table format thereof, respectively.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Now, the embodiments of the present invention will be described with reference to the drawings.
Embodiment 1
FIG. 1 is a block diagram of the first embodiment of an on-board navigation system for a vehicle according to the present invention. A data processor 4 computes the probability density of a vehicular position every moment in accordance with a method to be described later, on the basis of running distance data which is the output of running distance detection means 1 for measuring the revolution number of a wheel or the like, vehicular azimuth data which is the output of vehicular azimuth detection means 2 for measuring a steering angle, a terrestrial magnetism or the like, and map data stored in a memory 5. The result of the computation is written into an image memory 6 and displayed on an image display device 7 together with the map data. The driver of the vehicle can know his position in a map from the display.
FIG. 2 shows a display example on the display device 7. The map data, such as roads, 27 and vehicular position information 22 are displayed on a screen 20. The information is produced from the probability density 30 of the vehicular position as shown in FIG. 3. That is, the display in which the magnitudes of the probability densities of individual points (x, y) can be read is presented. By way of example, the points are displayed as brightnesses or in colors changed according to the magnitudes.
Next, there will be described the contents of the vehicular position estimation processing in the data processor 4. Let's consider a geometrical model as shown in FIG. 4. In a map coordinate system 40, the state of the vehicle is defined to be x=(xy) T . The running distance V i and azimuth θ i of the vehicle in each of time zones into which a period of time is divided at regular intervals, are respectively afforded by the detection means 1 and 2. On this occasion, a route 41 can be expressed by the following probability equation:
x.sub.i+1 =x.sub.i +d.sub.i (17)
In addition, an observation equation becomes as follows:
y.sub.i =d.sub.i +G.sub.i w.sub.i
(i=0, 1, . . . ) (18)
where ##EQU9##
Here, w i denotes the detection errors of the quantities v i and θ i , which can be regarded as white noise. When the probability density p(x 0 ) of the initial value x 0 of the position of the vehicle at the start of the running of the vehicle or at the start of the vehicular position display is now given, the probability densities p(x i ) of the subsequent states x i can be calculated from Eq. (17). The boundary line of 1δ for (i=1, . . . ) p(x i ) becomes as indicated by a closed curve 42. Areas enclosed with the closed curves 42 increase with `i` due to the disturbances w i . That is, the vehicular position becomes indefinite gradually. Here, the probability density p(x 0 ) can be given as stated below by way of example. By means of a console 8, the user indicates and inputs the current position of the vehicle judged by himself/herself within the map image which is displayed on the display device 7. The processor 4 evaluates p(x 0 ) from the positional information. When the position of the indicative input lies on a road in the map display, p(x 0 ) is given as a density distribution 51 centering around the indicated position on the road 50 as illustrated in FIG. 5. In contrast, when the indicative input position does not lie on a road in the map display, p(x 0 ) is given as a density function 60 spreading on an (x, y)-plane around the indicated position as illustrated in FIG. 6. The density function is in the shape of for example, a Gaussian distribution. Besides, in a case where the shape of the density function of x 0 dependent upon the position in the map is known from the distributions of narrow streets, vacant lots, etc., it may well be given as p(x 0 ). Such a functional shape may well be found by deciding the position, the kind of the road, etc. in the processor 4.
The estimation of the vehicular position using the map data conforms to the foregoing system in which the posterior conditional probability of Eq. (3) is maximized. Here, restrictive conditional probabilities p(x i+1 |x i ) (i=0, 1, . . . ) are given as stated below in accordance with the map data.
In a case where the current location x i lies on a section, such as a driveway (roadway), in which the vehicle does not go out of the road, the conditional probability p(x i+1 |x i ) is afforded as a unidimensional conditional probability density 71 which is distributed on the road 70 in the map as shown in FIG. 7. In this case, a conditional probability P(x x+1 |x i ) may well be afforded as a conditional probability density 271 which is uniformly distributed on a road 270 as shown in FIG. 20. On the other hand, in a case where the current location x i lies on the driveway, but where a service area or the like which is not contained in the road data of the map exists near the lower stream of the vehicular running, or in a case where the location x i lies on an urban street or the like and is a spot from which the vehicle can run out of roads in the map, the conditional probability p(x i+1 |x i ) is afforded as a conditional probability density 81 which is distributed in two dimensions around the road 80 in the map as shown in FIG. 8. Further, in a case where the current location x i lies outside a road 90 in the map, namely, where it lies in the service area of the driveway, the narrow street of an urban district, a parking area, or the like, the conditional probability p(x i+1 |x i ) is afforded as a two-dimensional conditional probability density 92 which is distributed in two dimensions near the current location x i 91 as shown in FIG. 9. The conditional probability p(x i+1 |x i ) indicates the conditional probability density of a vehicular position x i+1 which can be assumed at the next point of time with the position x i as a start point, and it can be evaluated from the possible lowest and highest speeds, a diversion probability at a branching point, etc. for each of the cases of the relationship between the road and the location x i . Also in this case, a conditional probability P(x i+1 |x i ) may well be afforded as a conditional probability density 281 which is distributed around a road 280 as shown in FIG. 21.
Further, a current vehicular speed may well be estimated from the output of a distance meter or a speedometer carried on the vehicle and be utilized.
Now, there are evaluated the time series x 1 , . . . and x N of the states which maximize the posterior conditional probability of Eq. (3) for the given state equation (17), observation equation (18), initial probability density p(x 0 ) and observation data y i (i=0, . . . , and N-1). First, for N=1, conditional probability densities p(x 1 |y 0 ) are found for all values which can be taken as x 1 , in accordance with Eq. (5). The state x 1 which takes the maximum value of the conditional probability densities corresponds to the most probable location of the vehicle at this point of time. The conditional probability density p(x 1 |y 0 ) is stored in a memory 9 in FIG. 1 so as to be utilized at the next point of time, and it is also sent to the memory 6 so as to be displayed. At the point of time of or after N=2, as illustrated in FIG. 10, the posterior probability p(x N-1 |y 0 , . . . , y N-2 ) 100 evaluated at the preceding point of time is read out of the memory 9, and conditional probability densities p(x N-1 |y 0 , . . . , y N-1 ) are obtained for all values which x N can take, in accordance with Eq. (4) and by the use of an observation y N-1 101, the obtained result being written into the memory 9 (103) and being sent to the memory 6 so as to be displayed.
The boundary line of 1δ for the obtained posterior conditional probabilities becomes as indicated at numeral 110 in FIG. 11, and an area enclosed with the curve 110 becomes smaller than in the case of the curve 42 in FIG. 4. This signifies decrease in the error of the estimation.
Thus, the vehicular position at the current time can be read together with the reliability thereof. The point at which the conditional probability becomes the maximum is the expected value of the current position. In a case where a road diverges in FIG. 2 and where significant posterior conditional probability values exist on two or more roads, all the values may be displayed as indicated at numeral 23.
Here, the computations need to be performed for all the continuous values x N which can take the posterior conditional probability p(x N |y 0 , . . . , y N-1 ). In the actual processing, however, they may be performed for points obtained by sampling the map coordinates at suitable intervals.
On this occasion, the integral calculations of Eqs. (4) and (5) become the sums of products.
Incidentally, the value of p(y i ) (i=0, . . . , and N-1) may be found so that the integration of p(x N |y 0 , . . . , y N-1 ) with respect to x N may become one.
Embodiment 2
The second embodiment consists in substituting the processing contents of the processor 4 which constitutes the first embodiment of the navigation system carried on the vehicle. Here, similarly to the foregoing, the initial probability density p(x 0 ) and the conditional probability density p(x i+1 |x i ) i=0, . . . , and N-1) are given beforehand. The processor 4 executes the following processing as indicated in FIG. 12:
There are evaluated the series x 0 , x 1 , . . . and x N of the states which maximize the posterior conditional probability of Eq. (6) for the given state equation (17), observation equation (18), initial probability density p(x 0 ) and observation data y i (i=0, . . . , and N-1). First, for N=1, J 1 (x 1 ) is found for all values which can be taken as x 1 , in accordance with Eq. (11). J 1 (x 1 ) corresponding to the maximum value of the posterior conditional probability density p(x 0 , (x 1 |y 0 ) obtained when x 1 is given, is stored in the memory 9 so as to be utilized at the next point of time. The conditional probability density p(x 0 ,x 1 |y 0 ) is sent to the memory 6 so as to be displayed. At the point of time of or after N=2, as illustrated in FIG. 12, a cost J N-1 (x N-1 ) 120 which corresponds to the maximum value of the following posterior conditional probability obtained when x N-1 evaluated at the preceding point of time is read out of the memory 9:
p (x.sub.0, x.sub.1, . . . , x.sub.N-1 |y.sub.0, . . . , y.sub.N-2)
C(x N , x N-1 ) is obtained for all values which x N can take, in accordance with Eq. (8) and by the use of an observation y N-1 121, and J N (x N ) 123 is evaluated from the two in accordance with Eq. (10) and is written into the memory 9 (122). J N (x N ) is the maximum value of the following posterior conditional probability obtained when x N is given:
p (x.sub.0, x.sub.1, . . . , x.sub.N |y.sub.0, y.sub.N-1)
It is sent to the memory 6 so as to be displayed. The display may be presented by the same method as in the first embodiment.
The posterior conditional probability displayed at each point of time:
p(x.sub.0, x.sub.1, . . . , x.sub.N |y.sub.0, . . . , y.sub.N-1)
indicates the posterior conditional probability in the case where the optimum route is taken in the sense of the maximum posterior conditional probability with the noticed state x N as a terminal end. If a vehicular route 111 in the past is to be known, processing as described below may be executed in the processor 4. Eq. (10) is solved in the descending series of N on the basis of the state x N at the given terminal end point, whereby the states x N of the optimum routes are obtained in the descending series of N. On this occasion, the values d N and θ N in the past are required. For this purpose, the outputs of the detection means 1 and 2 may be stored in the memory 9 beforehand so as to read them out at need.
Here, J N (x N ) may be computed for respective points obtained by sampling all the values of x N which can be taken. In addition, a proper fixed value may be given as p(y i ) (i=0, . . . , and N-1). The posterior conditional probability obtained on this occasion has a value thus subjected to scaling.
Embodiment 3
Next, there will be described an embodiment in which a plurality of sorts of devices are disposed as either or each of the running distance detection means 1 and the vehicular azimuth detection means 2, thereby to relieve the influence of the error of the detection data being the output of the detection means and to heighten the estimation accuracy of the current position of the vehicle. The running distance detection means to be added here is, for example, an inertial navigation system. Besides, the vehicular azimuth detection means is means for measuring the difference between the rotational angles of both the right and left wheels, the azimuth of the sun or a specified celestial body, or the like. On this occasion, the processing of the processor 4 may be changed as stated below: Now, letting V i ' denote the running distance of the vehicle as measured in the i-th time zone by the additional detection means, and θ i ' denote the vehicular azimuth, the following is obtained as an observation equation in addition to Eq. (18):
y.sub.i '=d.sub.i +G.sub.i 'w.sub.i (18')
where ##EQU10## On this occasion, the observation vector y i based on Eq. (18) and the observation vector y i ' mentioned above are combined to prepare a new 4-dimensional observation vector: ##EQU11## whereupon the estimative value of the current position x i which maximizes the posterior conditional probability of Eq. (3) or Eq. (6) may be found by replacing the observation vector y i of Eq. (2) with the new observation vector. Herein, the procedure of the processing is similar to that in the first or second embodiment. However, the number of the dimensions of the observation vector increases. Besides, in a case where an observation vector y i " based on the third detection means is obtained, the following 6-dimensional observation vector may be employed: ##EQU12## The same applies in cases of observation vectors of more increased dimensions. Here, in the case where the plurality of detection means are disposed, the abnormality of detection data can be sensed as described below: First, in case of the detection means, such as terrestrial magnetism azimuth sensor, which is greatly affected by a disturbance, the output thereof is compared with that of a sensor of high reliability such as gyro, and when the difference between both the outputs is larger than a predetermined threshold value, the output of the terrestrial magnetism azimuth sensor is regarded as being abnormal. Besides, in case of providing at least three sensors, the outputs of the respective sensors are compared, and when one output differs from the two others in excess of a predetermined threshold value, it is regarded as being abnormal.
Embodiment 4
Next, there will be described the fourth embodiment in which means 3 for detecting information on the current position of the vehicle is provided in addition to the detection means 1 and 2. Such means includes the GPS and the radio beacons of sign posts, loran etc. A measure in which a flying machine maintained at a high altitude so as to be used as the radio beacon, and a measure in which the inclination of the body of the vehicle is detected on the basis of the suspension of the wheels or the load of the engine of the vehicle as stated later, correspond also to this means. Herein, the processing of the processor 4 may be changed as follows: According to the detector 3, an observation equation (21) may be formularized:
z.sub.i =h.sub.i (x.sub.i)+v.sub.i (i=1, 2, . . . ) (21)
Here, z denotes an observation vector of m-th order, h an m-th order vector function, and v a white noise vector of m-th order, the probability density p(v) of which is assumed to be given.
On this occasion, as to the first embodiment, the observation of Eq. (21) is added instead of Eq. (3), and the following posterior conditional probability is maximized:
P (x.sub.N |y.sub.0, . . . Y.sub.n-1, z.sub.1, . . . , z.sub.N) (22)
Processing required for obtaining the solution of this problem becomes quite the same as in the foregoing when Eq. (4) is put as: ##EQU13## or Eq. (5) is put as: ##EQU14## As to the second embodiment, the observation of Eq. (21) is added instead of Eq. (8), and the following posterior conditional probability is maximized:
P (x.sub.0 x.sub.1, . . . ,x.sub.N |y.sub.0, . . . , y.sub.N-1, z.sub.1, . . . , z.sub.N) (23)
Processing required for obtaining the solution of this problem becomes quite the same as in the foregoing when the following is put in Eq. (8): ##EQU15##
By the way, in the case where the detection means 3 detects the inclination of the vehicular body, the output of the detector is z i in Eq. (21). In addition, h i (x i ) denotes the inclination of the road surface of the spot x i , and it may be included in the map data and stored in the memory 5. Besides, in a case where a plurality of position detection means are comprised, an observation vector Z i of large dimensions in which the outputs of the means are arrayed is substituted for z i , and the subsequent handling does not differ at all. Further, in the case of employing the vehicular position detection means 3 as stated above, the output thereof may be used for obtaining the probability density p(x 0 ) of the initial vehicular position in accordance with Eq. (21).
Embodiment 5
Next, there will be described the embodiment of processing which is executed for the abnormal detector data or map data in the processor 4. In the first embodiment,
∫∫p(y.sub.N-1 x.sub.N-1, . . . , x.sub.N)·p(x.sub.N |x.sub.N-1)·p(x.sub.N-1 y .sub.0, . . . , Y.sub.N-2) ·d x.sub.N-1 ·d x.sub.N (24)
is computed. From Eq. (4), it is transformed into:
∫p(x.sub.N |y.sub.0, . . . ,y.sub.N-1)·p(y.sub.N-1)d x.sub.N =p(y.sub.N-1) (25)
Accordingly, when the value of Eq. (24) is smaller than a predetermined threshold value, it can be decided that detector data y N-1 or map data p(x N |x N-1 ) has been abnormal. When the abnormality has been sensed, it is displayed on the display device 7 by way of example, so as to inform the user to that effect and to urge the user to input the current position information p(x 0 ) from the console 8. Then, the vehicular position estimation processing is reset, and it is changed-over to an estimation from the spot x 0 . In the presence of a plurality of detection means, an estimation may well be tried again by the use of the output data of the detection means other than ones decided abnormal.
Further, as regards the estimated result p(x N |y 0 , . . . , y N-1 ), the maximum value for the spot x N is detected. Thus, when the detected value is smaller than a predetermined threshold value, it can be decided whether the sensor detection data y N-1 or the map data p(x N |x N-1 ) has been abnormal, or in spite of the data being normal, the vehicular position has been lost because the running route pattern of the vehicle has no feature. Also in this case, the user may well be informed to that effect so as to reset the vehicular position estimation.
Besides, in the case where the vehicular position detection means 3 is provided, an abnormality can be sensed in the following way: The conditional probability density p(x i |z i ) of the position x i is evaluated from the output z i of the detector 3 in accordance with Eq. (21). On the other hand, the conditional probability density p(x i |y 0 , . . . , y i-1 ) of the position x i is evaluated without using the output of the detector 3, by the method of the first embodiment. In the absence of a region of x i where both the probability densities simultaneously take significant values greater than a predetermined threshold value, the latter density is regarded as being abnormal, and the position estimation from the current time is started anew with the former density being p(x 0 ).
Embodiment 6
Next, there will be described an embodiment in the case where the running of the vehicle is limited onto roads in the map data. This is applied to a navigation system which handles only driveways, or a navigation system with which the user receives service, consenting to the running on the roads in the map. In this case, the conditional probability p(x i+1 |x i ) of the vehicular position for use in the processing of the data processor 4 may be set so as to become zero when either x i or y i+1 does not lie on the road in the map. That is, it is given as indicated at numeral 71 in FIG. 7. In general, Embodiments 1 and 2 give the conditional probability p(x i+1 |x i ) as a two-dimensional distribution. In contrast, when the user has instructed from the console 8 to the effect that the drive limited onto the roads as stated above is to be performed, the conditional probability p(x i+1 |x i ) may be changedover to the unidimensional distribution as mentioned above and be utilized.
Here will be described the formats of the map data for use in the navigation system of the present invention and methods of utilizing the map data. Roads contained in the map data are expressed by nodes such as intersection points, branching points and bending points, and the links between the nodes as approximated by straight lines or circular arcs. As indicated in FIG. 13, the data format of the node consists of an identifier 131, an x-coordinate 132, y-coordinate 133 and z-coordinate 134 in a map coordinate system, an attribute 135, the number of connected links 136, link identifiers 137 in the number of the links, and other auxiliary information 138. As the attribute 135, besides the identifier of the intersection point, branching point or bending point, the user may well additionally write a service area, parking area, gasoline station or the like which is useful for the user to recognize the vehicular position or route. On the other hand, as indicated in FIG. 14, the data format of the link consists of an identifier 140, a start node identifier 141, an end node identifier 142, an attribute 143, the number of lanes 144, a maximum speed limit 145, a minimum speed limit 146, the diversion probabilities of traffic flow 147 at the start node, the diversion probabilities of traffic flow 148 at the end node, and other auxiliary information 149. The user may well additionally write the identifier of a driveway, urban street, suburban street or the like as the attribute 143, and regulation information etc. and other items convenient for the user as the auxiliary information 149. Incidentally, when the up and down directions of a road need not be distinguished, the start point and end point are changed to read as terminal points. In addition, the prior information items of measurement errors dependent upon places, such as the disturbances of a terrestrial magnetic sensor attributed to a railway, a high level road etc., may well be written in the auxiliary information 138 or 149 in terms of, for example, the values of biases or error covariances. Besides, as to sign posts, the error covariances thereof may well be stored in the auxiliary information 138. These map data items are stored in the memory 5. Here, fixed information items among the map data are stored in a read-only memory such as CD-ROM, while additional or variable information items are stored in a rewritable memory such as RAM. Alternatively, both the fixed and variable information items may be stored in an optomagnetic disk, a bubble memory or the like which is rewritable. The map data is utilized as follows by the processor 4:
(1) Using the data items of the coordinates and connective relations of nodes and links, a road map in the neighborhood of the current position of the vehicle is displayed on the display device 7. The links may well be selected or distinguished in colors in accordance with the attributes thereof. Besides, the attributes of the nodes serving as marks may well be displayed.
(2) There is evaluated the conditional probability density p(x i+1 |x i ) of the position x i+1 of the vehicle at the next point of time in the case where the current vehicular position x i has been given. As referred to in the description of the first embodiment, in a case where x i lies on or near a link, p(x i+1 |x i ) is evaluated by the use of the attribute of the link and the maximum and minimum speed limits thereof. Further, in a case where x i lies on or near a node, p(x i+1 |x i ) is evaluated by the use of the attribute, diversion probability etc. of the node. Here, the values 147 and 148 in the memory 5 may well be used as the diversion probabilities. However, when the vehicle is navigated along a route leading to a predetermined destination, different values may well be used as described below.
(3) The optimum route from a given start point or current position to the destination is calculated according to the connective relations of nodes and links, the distances of the links, speed limits, etc. The calculated route is overlay-displayed on a map by the display device 7, and the selections of courses at the respective nodes are displayed. On this occasion, the probabilities of diversions to the courses are made greater than the values stored in the map data, whereupon p(x i+1 |x i ) is calculated in conformity with the procedure (2).
(4) In a case where a sensor for detecting the inclination of a vehicular body is comprised as the sensor 3, the inclination of a noticed link is evaluated from the z-coordinate values of both the end nodes of the link and the distance of the link, and it is checked up with the sensor output by the foregoing method so as to be utilized for the estimation of a vehicular position.
(5) In a case where a sign post is employed as the sensor 3, the installation location and error covariance value thereof can be read out from the memory of the map data so as to be utilized for the estimation of a vehicular position.
(6) In a case where the vehicular azimuth detection means 2 is one, such as a terrestrial magnetism sensor, which undergoes different disturbances depending upon places, the prior information items of errors, namely, biases, covariances etc. can be read out from the map data memory so as to be utilized for the estimation of a vehicular position.
(7) The data items of nodes and links are retrieved using an estimated vehicular position as an index, and the identifiers, attributes, auxiliary information items etc. of the neighboring node and link are displayed and communicated to the user.
Embodiment 7
Next, the first embodiment of a location system which adopts the vehicular position estimating system according to the present invention will be described with reference to FIGS. 15-17. FIG. 15 is a general block diagram of the location system. This system is constructed of at least one on-board device 150 carried on a vehicle, and a single center device 151. Data items are transferred between both the devices by radio communication. FIG. 16 is a block diagram of the device 150. An on-board navigation system 161 is equivalent to that shown in FIG. 1. The estimated result of a vehicular position produced from a processor 4 in the system 161 is sent to the center device 151 through a transponder 162 as well as an antenna 163, together with the identifier of the vehicle. On the other hand, a command etc. sent from the center device 151 are utilized for display etc. by the processor 4 through the antenna 163 as well as the transponder 162. FIG. 17 is a block diagram of the device 151. The identifier of each vehicle and the estimated result of the position thereof as sent from the on-board device 150 are sent to a processor 172 through an antenna 170 as well as a transponder 171, and they are displayed on a display device 173 or are utilized for processing for the service management of the vehicle. A command etc. for the vehicle, which are given from an input device 174 by a service manager or prepared by the processor 172, are sent toward the vehicle through the transponder 171 as well as the antenna 170, together with the identifier of the vehicle.
Embodiment 8
Next, the second embodiment of the location system will be described with reference to FIGS. 18 and 19. The general arrangement of this system is the same as shown in FIG. 15. FIG. 18 is a block diagram of the on-board device 150. The outputs of detection means 1 thru 3 are sent to the center device 151 through a processor 4, a transponder 181 and an antenna 182 every fixed time, together with the identifier of the vehicle. On the basis of the received sensor outputs and map data, the center device 151 executes processing to be described below and estimates the position of the vehicle. The result is sent to the vehicle together with a command, and it is displayed on a device 7 through the antenna 182, the transponder 181, the processor 4 and a memory 6 so as to be communicated to the user of the system. On this occasion, map data stored in a memory 5 may well be overlay-displayed. FIG. 19 is a block diagram of the center device 151. The identifier and sensor outputs of each vehicle, which are sent from the on-board device 150, are delivered to a processor 192 through an antenna 190 as well as a transponder 191. The processor 192 executes the same processing as that of the processor 4 in Embodiment 1 or 2, and estimates the position of the vehicle. Herein, a memory 193 which stores the map data and an estimated result at the last sampling point of time and which corresponds to the memories 5 and 9 is utilized. The estimated result is displayed on a display device 194, or is utilized for processing for the service management of the vehicle. A command etc. for the vehicle, which are given from an input device 195 by a service manager or prepared by the processor 192, are sent toward the vehicle through the transponder 191 as well as the antenna 190, together with the positional estimation result and the identifier of the vehicle. As compared with the foregoing embodiments, this embodiment has the following features:
(1) The load of the on-board processor 4 is lower, and the size thereof can be reduced.
(2) The on-board memory 9 is dispensed with, and the map data in the memory 5 may contain only the attributes, connective relations etc. of nodes and links, so the size thereof can be reduced.
(3) The memory 5 is also dispensed with when a system in which the center device 151 prepares map image data for display and transmits it to the on-board device 150 is adopted.
(4) In the case where the position measurement device based on the GPS is employed as the detection means 3, this means 3 can be miniaturized by adopting a system in which a signal received from a satellite is sent to the center device 151 so as to execute the position calculation processing therein, instead of the on-board processing for calculating the position from the received signal. In consequence, this embodiment can simplify and miniaturize the on-board devices. It is also a modification to the navigation system.
In the navigation system of the present invention, the vehicular position estimated every moment may well be stored in the memory 9 together with the codes of a start point and a destination applied from the exterior 8. In that case, when the vehicle runs between the identical start point and destination after such running, a corresponding route can be guided to the driver in such a way that running spots on the route are read out from the memory 9 and displayed on the display device 7 in accordance with the codes of the start point and destination applied from the exterior 8. Here, x N (N=0, 1, . . . ) maximizing Eq. (4), Eq. (12) or Eq. (13) can be used as the vehicular positions to be stored in the memory 9.
Although, in each of the foregoing embodiments, the display device 7 has been employed as the means for communicating the estimated result of the current position of the vehicle to the user, it may well be replaced with a voice synthesizer 10 (in FIG. 1). The sentences of, for example, "You are approaching Intersection --" and "You are near--" are synthesized and communicated as voice in accordance with the probability densities of the estimated results and the coordinates of the nodes and links in the map data. This expedient produces the effect that, when the user is the driver, the burden of seeing the display during running can be avoided.
According to the embodiments thus far described, the current position of a vehicle is estimated using map data, and hence, there is the effect that the divergence of an estimation error ascribable to the error of other detector data is suppressed.
Moreover, since the probability density of the vehicular position is displayed on a map, there is the effect that the user can know the reliability of an estimated result and prevent a confusion ascribable to an erroneous display.
Furthermore, since the estimation system of the present invention can collectively handle various kinds of detector data, there is the effect that the achievement of a high accuracy is facilitated by combining the system with the detector of a GPS or the like.
Embodiment 9
FIG. 22 shows an on-board navigation system which adopts the present invention. In beginning the use of the navigation system, a driver (or another occupant) 301 designates a road map including a current position, from a device 302 for inputting the indication of a start map. Then, road data on a CD-ROM 304 is read out by an input device 305 and displayed on an image display device 303. The road data is once stored in a road node table 306 and is converted by picturization means 307 into bit map data, which is sent to the image display device 303. The road data is expressed by the node table which is exemplified in FIGS. 25(a) and 25(b). The picturization means 307 evaluates the formulae of straight lines between adjacent nodes for all the nodes, and alters pixel values on the straight lines from background density (color) values into road density (color) values in a write image buffer. When the road image as shown in FIG. 25(a) is displayed on the image display device 303, the driver 301 inputs the current position of a vehicle with a device 308 for inputting the indication of a start point, which is constructed of a cursor moving device, while viewing the display of a cursor on the image display device 303. In conformity with this timing, an azimuth calculator 3011 for ΔS intervals begins to receive a running distance S(t) and a vehicular azimuth θ v (t) from a distance sensor 309 and an azimuth sensor 310 constructed of a terrestrial magnetism sensor, respectively, and it delivers running directions θ v (j) (j=0, 1, . . . ) of the respective fixed distances ΔS in succession. Simultaneously with the input of the indication of the start point, the coordinates of the start point on the image are applied to a road direction calculator 3012 for the ΔS intervals. The road direction calculator 3012 first finds a point on the road data nearest the start point coordinates as received by loading the road node table 306, and sets it as the coordinates A of the new start point. Subsequently, the calculator 3012 evaluates the road direction data θ r (i) of points at the respective fixed distances ΔS, for all road routes which can be reached from the point A, and it sends the evaluated data to a road direction data file 3013. The number of the road direction data items, namely, the size of the file is set to be double the maximum trajectory length M of DP matching. At the same time, the road direction calculator 3012 supplies a road coordinate data file 3014 with the coordinates {x r (i), y r (i)} of the points at the intervals ΔS. When a DP calculator 3015 is supplied with the vehicular direction data θ v (0) and θ v (1) from the azimuth calculator 3011 for the ΔS intervals with the proceeding of the vehicle, the minimum costs of three lattice points (0, 1 ), (1, 1) and (2, 1) in FIG. 24(a) are computed according to Eq. (16) and are delivered to a minimum cost file 3016. When the vehicle proceeds to pass the point of j=2, θ v (2) is delivered from the azimuth calculator 3011. Then, the DP calculator 3015 reads out the minimum cost values J * (0, 1), J * (1, 1) and J * (2, 1) stored at the last time, from the minimum cost file 3016, and it calculates the minimum cost values J * (i, 2) (i=1, . . . and 4) at j=2 in accordance with Eq. (16) by the use of the road direction angles θ r (i) (i=0, 1, 2, 3 and 4) received from the road direction data file 3013, the calculated results being stored in the minimum cost file 3016. As stated before, the DP calculator 3015 executes the final stage of the DP matching calculation between the trajectory and the route of the road data in conformity with the running of the vehicle. A minimum cost detector 3017 detects i min which affords the minimum value concerning `i` of J * (i, j) in the minimum cost file 3016, every running distance `j`. A compensated position calculator 3018 loads the coordinates of a position on the map corresponding to i min , namely, the optimal matching point of the vehicular distance `j`, from the road data coordinate file 3014, and delivers them to the picturization means 307, thereby to display the vehicular position as a compensated position in superposition on the map coordinates indicated on the image display device 303, and it also delivers them to the input device 305, thereby to read out road data centering around the vehicular position. Besides, each time i min increases with the proceeding of the vehicle, the road direction calculator 3012 for the ΔS intervals evaluates a road direction and coordinate data corresponding to an increment and supplements them to the road direction data file 3013 and the road coordinate data file 3014. Incidentally, the DP calculator 3015 checks the computed cost J * (i, j), and it stops the DP calculations as illustrated in FIG. 24(b) when the cost has exceeded a threshold value α. In a case where, as shown in FIG. 23, all the costs J * (i, j) concerning the running distance `j` have exceeded the threshold value α after branching at an intersection, the computation of the road direction data on this branching is not executed thenceforth.
Owing to the repetition of the above operations, the vehicular position compensated by the optimum matching as the route is displayed on the image display device 303 every moment with the running of the vehicle.
According to Embodiment 9, when a vehicular position is estimated from on-board sensor data in an on-board navigation system, the global matching between an on-board sensor data sequence and map road data and the correction of an estimated vehicular position are made by a DP matching technique. This is effective to provide the on-board navigation system which lowers the possibility of the failure of the vehicular position estimation attributed to insufficiency in the map data and sensor errors and in which temporary mismatching can be corrected by a posterior global judgement. | In a navigation system which has sensors for detecting a running distance, an azimuth, etc. of a vehicle, and a memory for storing map data; a probability density of a position of the vehicle is calculated on the basis of the sensor outputs and the map data for each of quantization units with which a probability computation determined by detection accuracies of the sensors and quantization of the map data can be executed. In addition, a final stage calculation of DP matching between trajectory data obtained from the on-board sensor data from a start point of the vehicle until a current time and a candidate route estimated from the road map data is iteratively executed, whereby a plurality of estimative vehicular positions and uncertainties (costs) corresponding to the respective estimative positions are iteratively evaluated, and a correct vehicular position is estimated by selecting at least one estimative vehicular position of low uncertainty (cost). | 6 |
RELATED APPLICATION DATA
The present application claims priority to Japanese Application No. P11-312070 filed Nov. 2, 1999, which application is incorporated herein by reference to the extent permitted by law.
BACKGROUND OF THE INVENTION
This invention relates to an organic electroluminescent device, which is adapted for use as a display device or a light-emitting device such as a spontaneous light flat display, especially an organic electroluminescent color display using an organic thin film as an electroluminescent layer.
In recent years, importance of interfaces between human beings and machines including multimedia-oriented commercial articles is exalted. For more comfortable and more efficient machine operations, it is necessary to retrieve information from an operated machine without failure simply, instantaneously and in an adequate amount. To this end, studies have been made on various types of display devices or displays.
As machines are now miniaturized, there is an increasing demand, day by day, for miniaturization and thinning of display devices. For instance, there is an inconceivable development with respect to the miniaturization of lap top-type information processors of the all-in-one type such as notebook-size personal computers, notebook-size word processors and the like. This, in turn, entails a remarkable technical innovation on liquid crystal displays for use as a display device for the processor.
Nowadays, liquid crystal displays are employed as an interface of a diversity of articles and have wide utility in the fields not only of lap top-type information processors, but also of articles for our daily use including small-sized television sets, watches, desk-top calculators and the like.
These liquid crystal displays have been studied as a key of display devices, which are used as the interface connecting a human being and a machine and cover small-sized to large capacitance display devices while making use of the feature that liquid crystals are low in drive voltage and power consumption. However, liquid crystal displays have the problems that they do not rely on spontaneous light and thus need a greater power consumption for back light drive than for liquid crystal drive, with the result that a service time is shortened when using a built-in battery, thus placing a limitation on their use. Moreover, the liquid crystal display has another problem that it has such a narrow angle of field as not to be suitable for use as a large-sized display device.
Furthermore, the liquid crystal display depends on the manner of display using the orientation of liquid crystal molecules, and this is considered to bring about a serious problem that its contrast changes depending on the angle even within an angle of field.
From the standpoint of drive systems, an active matrix system, which is one of drive systems, has a response speed sufficient to deal with a motion picture. However, since a TFT (thin film transistor) drive circuit is used, a difficulty is involved in making a large screen size owing to the pixel defects, thus being disadvantageous in view of the reduction in cost.
In the liquid crystal display, a simple matrix system, which is another type of drive system, is not only low in cost, but also relatively easy in making a large screen size. However, this system has the problem that its response speed is not enough to deal with a motion picture.
In contrast, a spontaneous light display device is now under study such as on a plasma display device, an inorganic electroluminescent device, an organic electroluminescent device and the like.
The plasma display device employs plasma emission in a low pressure gas for display and is suited for the purposes of a large size and large capacitance, but has the problem on thinning and costs. In addition, an AC bias of high potential is required for its drive, and thus, the display is not suitable as a portable device.
The inorganic electroluminescent device has been put on the market as a green light emission display. Like the plasma display device, an AC bias drive is essential, for which several hundreds of volts are necessary, thus not being of practical use.
In this connection, however, emission of three primaries including red (R), green (G) and blue (B) necessary for color display has been succeeded due to the technical development. Since inorganic materials are used for this purpose, it has been difficult to control emission wavelengths depending on the molecular design or the like. Thus, it is believed that full color display is difficult.
On the other hand, the electroluminescent phenomenon caused by organic compounds has been long studied ever since there was discovered a luminescent or emission phenomenon wherein carriers are injected into the single crystal of anthracene capable of emitting a strong fluorescence in the first part of 1960s. However, such fluorescence is low in brightness and monochronous in nature, and the single crystal is used, so that this emission has been made as a fundamental investigation of carrier injection into organic materials.
However, since Tang et al. of Eastman Kodak have made public an organic thin film electroluminescent device of a built-up structure having an amorphous luminescent layer capable of realizing low voltage drive and high brightness emission in 1987, extensive studies have been made, in various fields, on the emission, stability, rise in brightness, built-up structure, manner of fabrication and the like with respect to the three primaries of R, G and B.
Furthermore, diverse novel materials have been prepared with the aid of the molecular design inherent to an organic material. At present, it starts to conduct extensive studies on applications, to color displays, of organic electroluminescent devices having excellent characteristic features of DC low voltage drive, thinning, and spontaneous light emission and the like.
The organic electroluminescent device (which may be sometimes referred to as organic EL device hereinafter) has a film thickness of 1 μm or below. When an electric current is charged to the device, the electric energy is converted to a light energy thereby causing luminescence to be emitted in the form of a plane. Thus, the device has an ideal feature for use as a display device of the spontaneous emission type.
FIG. 14 shows an example of a known organic EL device. An organic EL device 10 includes, on a transparent substrate 6 (e.g. a glass substrate), an ITO (indium tin oxide) transparent electrode 5 , a hole transport layer 4 , a luminescent layer 3 , an electron transport layer 2 , and a cathode 1 (e.g. an aluminium electrode) formed in this order, for example, by a vacuum deposition method.
A DC voltage 7 is selectively applied between the transparent electrode 5 serving as an anode and the cathode 1 , so that holes serving as carriers charged from the transparent electrode 5 are moved via the hole transport layer 4 , and electrons charged from the cathode 1 are moved via the electron transport layer 2 , thereby causing the re-combination of the electrons-holes. From the site of the re-combination, light 8 with a given wavelength is emitted and can be observed from the side of the transparent substrate 6 .
The luminescent layer 3 may be made of a light-emitting substance such as, for example, anthracene, naphthalene, phenanthrene, pyrene, chrysene, perylene, butadiene, coumarin, acridine, stilbene and the like. This may be contained in the electron transport layer 2 .
FIG. 15 shows another example of an organic EL device. In an organic EL device 20 , the luminescent layer 3 is omitted and, instead, such a light-emitting substance as mentioned above is contained in the electron transport layer 2 , and thus, the organic EL device 20 is so arranged as to emit light 18 having a given wavelength from an interface between the electron transport layer 2 and the hole transport layer 4 .
FIG. 16 shows an application of the organic EL device. More particularly, a built-up body of the respective organic layers (including the hole transport layer 4 , and the luminescent layer 3 or the electron transport layer 2 ) is interposed between the cathode 1 and the anode 5 . These electrodes are, respectively, provided in the form of stripes that are intersected in the form of a matrix. In this state, a signal voltage is applied to in time series by means of a luminance signal circuit 34 and a shift register-built in control circuit 35 so that light is emitted at a number of intersected points (pixels), respectively.
Such an arrangement as set out above is usable not only as a display, but also as an image reproducing apparatus. It will be noted that if the striped pattern is provided for the respective colors of R, G and B, there can be obtained a full color or a multi-color arrangement.
In a display device made of a plurality of pixels using the organic EL device, emitting organic thin film layers 2 , 3 and 4 are usually sandwiched between the transparent electrode 5 and the metal electrode 1 , and emission occurs at the side of the transparent electrode 5 .
The organic EL device set out above still has problems to solve. For instance, upon application of the organic EL device to a color display, it is essentially required to stably emit primaries of R, G and B. At the present stage, however, there have never been reported, except green light emitting materials, red and blue materials that have stability, chromaticity, brightness and the like enough to apply to displays.
Especially, with respect to blue emission of good chromaticity, it has now been difficult to obtain stable emission owing to the generation of heat from the course of a thermal relaxation procedure involving light emission and the presence of singlet oxygen or the like.
Moreover, where a dye of high crystallinity is used, an oligomer is produced upon solidification. This leads to a longer emission wavelength, with the high possibility that there occurs a phenomenon where even if emission takes place, it ceases immediately.
Many studies have been made on the development of a novel blue light-emitting material. Along with the study and development of a novel substance, it is important to obtain stable emission by application of existing materials. Additionally, the use of a material that has been established to some extent from the standpoint of its behavior contributes greatly to the shortage of time in the study and development, thus indicating an index to the development of materials.
For instance, a coumarin-based laser dye with a high fluorescent yield can be applied to as a doping material for improving the color purity of green emission, and has now been reported as obtaining an emission as a blue light-emitting material. This is considered for the following reason: a coumarin-based, short wavelength fluorescent dye is usually high in crystallinity in the form of a simple substance and is not suited as a stable blue emission material in an amorphous form; and at present, an amorphous stable thin film can be obtained according to a co-deposition technique.
For instance, coumarin 450 has a maximum fluorescent wavelength in the vicinity of 446 nm and a chromaticity corresponding to blue among R, G and B. However, coumarin has no electron transportability or hole transportability, so that its characteristics as a luminescent material is apparently poorer in comparison with materials having electron or hole transportability.
Materials, typical of which are zinc metal complexes, enable one to obtain stable blue emission by forming a blue luminescent layer having electron transportability as a single hetero-type structure. However, when an applied voltage is increased in order to obtain a satisfactory brightness, emission predominantly occurs in a region of a good spectral luminous efficacy at an emission spectrum in the vicinity of 700 nm. Eventually, there arises the disadvantage that the chromaticity of blue emission is shifted and comes close to white emission.
Further, the life of an organic electroluminescent device is generally short, and studies for prolonging the life have been extensively made in various fields.
However, for practical application as a display, it is preferred that a half-life time from an initial brightness (of about 200 cd) is 10,000 hours or over. Such an endurance time cannot be obtained yet. This presents a serious problem to solve in order to put the organic electroluminescent devices to practical use.
SUMMARY OF THE INVENTION
An object of the invention is to provide an organic electroluminescent device, which is able to realize blue emission of good chromaticity in a high luminous efficiency and high brightness.
Another object of the invention is to provide an organic electroluminescent device, which is able to continue stable emission over a long time.
Under the circumstances in the art, we have made intensive studies on applications of existing materials whose natures are well known, thereby causing amorphous thin films capable of emitting luminescence of good chromaticity in high brightness to efficiently emit luminescence. This will lead to considerable shortage of time in study and development, to realization of full color arrangements including a color display and also to contribution to the prolonged life of the device.
More particularly, according to the invention, there is provided an organic electroluminescent device of the type which comprises an emission region made of an organic compound and is constituted of a built-up body made of organic substances and including the emission region, wherein a portion contacting a main emission region contains a bathophenanthroline derivative of the general formula
General Formula:
wherein X and Y may be the same or different and independently represent a hydrogen atom except the case where a hydrogen atom is at the 2 or 9 position, a substituted or unsubstituted alkyl group except the case where a methyl group is at the 2 or 9 position, a substituted or unsubstituted cycloalkyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted amino group, a halogen atom, a nitro group, a cyano group or a hydroxyl group provided that at least one of these groups is contained at an arbitrary position.
In the electroluminescent device of the invention, the bathophenanthroline derivative that is contained in a portion contacting the main emission region acts to block the transport of holes, so that emission is obtained through electron-hole re-combination in a hole transport organic material (i.e. a hole transport layer has such a structure serving also as a luminescent layer that is an electron-hole re-combination region), so that stable emission of high brightness, especially, blue emission, is enabled by low voltage drive. The bathophenanthroline derivative has emission properties. Accordingly, there can be obtained not only light emission from the hole transport layer, but also emission from the bathophenanthroline derivative. At least one of the above emissions can be obtained.
Although fabrication of an organic electroluminescent device, and particularly, an amorphous organic electroluminescent device of the low voltage drive, spontaneous emission and thin type, has been considered to be difficult in view of its structure due to the absence of an electron transport material with excellent non-luminous properties, the invention can provide an organic electroluminescent device wherein its hole transport layer serves also as a luminescent layer that is a re-combination region of electrons and holes and which has a device structure of a long life capable of continuing stable emission over a long time.
More particularly, when an organic electroluminescent device is so arranged as to comprise a hole transport layer as a luminescent layer, stable emission can be obtained in high brightness and high efficiency. Especially, this becomes more appreciable with respect to blue emission, enabling one to obtain a peak brightness of 10,000 cd/m 2 or over by DC drive and a peak brightness, calculated as DC, of 55,000 cd/m 2 by pulse drive with a duty ratio of {fraction (1/100)}.
Aside from the blue emission device, bluish green emission, red or yellow emission via doping, and the control in chromaticity by doping are possible. Thus, there can be fabricated an organic electroluminescent-in-blue device capable of blue emission with an excellent chromaticity in high brightness. Hence, the possibility and shortage in time of development of materials, and indices to designs of novel luminescent materials and electron transport material can be shown.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic sectional view showing an essential part of an organic electroluminescent device according to a first embodiment of the invention;
FIG. 2 is a view showing the general formula of a bathophenanthroline derivative usable in a hole-blocking layer of the organic EL device;
FIG. 3 is a view showing structural formula 1 of a bathophenanthroline derivative usable in the hole-blocking layer;
FIG. 4 is a view showing structural formula 2 of a bathophenanthroline derivative usable in the hole-blocking layer;
FIG. 5 is a view showing structural formula 3 of a bathophenanthroline derivative usable in the hole-blocking layer;
FIG. 6 is a view of a band model schematically showing a built-up structure of the organic EL device of the first embodiment;
FIG. 7 is a schematic sectional view showing a vacuum deposition apparatus used in the first embodiment;
FIG. 8 is a plan view showing the organic EL device of the embodiment;
FIG. 9 is a schematic sectional view showing an essential part of an organic EL device according to a second embodiment of the invention;
FIG. 10 is a schematic sectional view showing an essential part of an organic EL device according to a third embodiment of the invention;
FIG. 11 is a view showing a structural formula of m-MTDATA (i.e. a hole transporting luminescent material) used in the third embodiment;
FIG. 12 is a view showing a structural formula of α-NPD (i.e. a hole transporting luminescent material) used in the third embodiment;
FIG. 13 is a view showing a structural formula of Alq 3 (i.e. an electron transport material) used in the third embodiment;
FIG. 14 is a schematic sectional view showing an example of a prior-art organic EL device;
FIG. 15 is a schematic sectional view showing an example of another type of prior-art organic EL device; and
FIG. 16 is a schematic perspective view showing an example of further another type of prior-art organic EL device.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
In the electroluminescent device of the invention, the emission region is mainly composed of an organic hole transport layer, and it is preferred that a hole-blocking layer is provided in order to cause the re-combination in the hole transport layer.
It is also preferred that the hole-blocking layer is provided between the hole transport layer and an electron transport layer.
Moreover, it is preferable that the highest occupied molecular orbital (HOMO) level of the hole-blocking layer is not higher than a highest occupied molecular orbital level (HOMO) that is a lower one in energy of the highest occupied molecular orbital (HOMO) levels of the respective organic layers (especially, the hole transport layer and the electron transport layer) in contact with opposite sides of the hole-blocking layer.
Moreover, the lowest unoccupied molecular orbital (LUMO) level of the hole-blocking layer should preferably be not lower than a lowest unoccupied molecular orbital (LUMO) level that is a lower one in energy of the lowest unoccupied molecular orbital (LUMO) levels of the respective organic layers (especially, the hole transport layer and the electron transport layer) built up in contact with opposite sides of the hole-blocking layer and not lower than the lowest unoccupied molecular orbital (LUMO) level that is a higher one in energy.
In addition, the hole-blocking layer should preferably be made of a non-luminous material with a low fluorescent yield and may be made of a built-up structure including a plurality of layers.
Moreover, no limitation is placed on the hole-blocking layer with respect to the kind of material therefor. In order to prevent the formation of an exciplex (dimer) (i.e. the lowering of a luminous efficiency) at the interface with the hole transporting luminescent layer, a non-luminous material with a low fluorescent yield is preferred.
The emission region should favorably be made of a hole transport material for short wavelength emission. The materials usable as the hole-blocking layer should preferably include bathophenanthroline derivatives of the general formula indicated in FIG. 2 . Specific examples include those of Compound Nos. 1 to 178 indicated below and including structural formulas 1 to 3 indicated in FIGS. 3 to 5 , respectively, although not limited to those mentioned above. In the exemplified compounds, Me represents a methyl group, Et represents an ethyl group, Pr represents a propyl group, and Bu represents a butyl group.
The device should preferably comprise, on an optically transparent substrate, a transparent electrode, the above-stated organic built-up body (including an organic hole transport layer, a hole-blocking layer, and an organic electron transport layer) and a metal electrode superposed in this order.
The device having such an arrangement as mentioned above is suitable for use as a device for color display.
Preferred embodiment of the invention are now described.
First Embodiment
FIG. 1 is a schematic sectional view showing an essential part of an organic EL device capable of emitting blue luminescence according to the first embodiment of the invention.
In this embodiment, a transparent electrode, made of ITO (indium tin oxide) or Zn-doped indium oxide, is formed on a glass substrate 6 by sputtering or vacuum deposition, followed by successively forming a hole transporting luminescent layer 4 a , a hole transporting luminescent layer 4 b , a hole-blocking layer 33 containing a bathophenanthroline derivative of the afore-indicated general formula, an electron transport layer 2 , and a cathode electrode 1 in this order according to a vacuum deposition technique to form an organic electroluminescent device (organic EL device) 21 made of the amorphous organic thin films.
This organic EL device 21 has such an arrangement that the hole transport layer 4 serves also as a luminescent layer, and this fundamental structure is likewise employed in other embodiments described hereinafter.
The feature of the organic EL device 21 of this embodiment resides in that the bathophenanthroline derivative-containing layer 33 is interposed, as a hole-blocking layer, between the hole transport layer 4 and the electron transport layer 2 , so that the re-combination of electrons-holes is promoted in the hole transport layer 4 , at which luminescence is emitted, and/or luminescence is also obtained from the bathophenanthroline derivative-containing layer 33 .
FIG. 6 schematically shows the built-up structure of the organic EL device of this embodiment in FIG. 1 as a band model.
In FIG. 6, the thick lines (L 1 , L 2 ) indicated at the cathode 1 made of Al and Al-Li (aluminium-lithium,) and the ITO transparent electrode 5 layer, respectively, mean approximate work functions of the respective metals. In the respective.layers between the electrodes, upper thick lines l 1 , l 2 , l 3 and l 4 and numerical values thereof indicate the lowest unoccupied molecular orbital (LUMO) levels, and lower thick lines l 5 , l 6 , l 7 and l 8 and numerical values thereof indicate the highest occupied molecular orbital (HOMO) levels, respectively. It is to be noted that the energy levels in FIG. 6 are shown only by way of example and may widely vary depending on the types of materials.
In the organic EL device, as shown in FIG. 6, the holes h charged from the transparent electrode 5 serving as an anode are moved via the hole transport layer 4 . On the other hand, electrons e charged from the metal electrode 1 serving as a cathode are moved via the electron transport layer 2 . The electrons-holes are re-combined in the hole transporting luminescent layer, at which luminescence is emitted.
The electrons e charged from the metal electrode 1 serving as a cathode has the tendency of moving toward a lower energy level, and can arrive at the hole transporting luminescent layers 4 b , 4 a via the lowest unoccupied molecular orbital (LUMO) levels l 1 to l 4 of the respective layers in the order of the metal electrode 1 , electron transport layer 2 , hole-blocking layer 33 , hole transporting luminescent layer 4 b and hole transporting luminescent layer 4 a.
On the other hand, the holes h charged from the ITO transparent electrode 5 serving as an anode has the tendency of moving toward a higher energy level, and can move to the electron transport layer 2 via the highest occupied molecular orbital (HOMO) levels l 5 to l 7 of the respective layers in the order of the hole transporting luminescent layer 4 a , hole transporting luminescent layer 4 b and hole-blocking layer 33 .
However, as shown in FIG. 6, the highest occupied molecular orbital (HOMO) level l 8 of the electron transport layer 2 is lower in energy than the highest occupied molecular orbital (HOMO) level l 7 of the hole-blocking layer 33 . This makes it difficult that the charged holes h moves from the hole-blocking layer 33 toward the electron transport layer 2 , and thus, they are filled in the hole-blocking layer 33 .
Eventually, the holes h filled in the hole-blocking layer 33 promote the re-combination of electrons-holes at the hole transport layer 4 , thereby permitting the luminescent materials of the hole transporting luminescent layers 4 a , 4 b of the hole transport layer 4 to emit luminescence or light.
In this way, the provision of the hole-blocking layer 33 effectively controls the transport of the holes h in the hole-blocking layer 33 so that the electron-hole re-combination in the hole transport layer 4 is efficiently caused. Thus, light with a specific wavelength (blue) is emitted in the form of light emission mainly from the hole transporting luminescent layer 4 b , adjoining to the hole-blocking layer 33 , of the light-emitting hole transporting luminescent layers 4 a , 4 b , to which emission from the hole transporting luminescent layer 4 a is added.
Fundamentally, the electron-hole re-combination takes place in the respective layers including the electron transport layer 2 and the hole transport layer 4 as resulting from the charge of electrons from the cathode electrode 1 and the charge of holes from the anode electrode 5 . Accordingly, in the absence of such a hole-blocking layer 33 as set out above, the electron-hole re-combination occurs at the interface between the electron transport layer 2 and the hole transport layer 4 so that light emission with a long wavelength alone is obtained. However, when the hole-blocking layer 33 as in this embodiment is provided, it is enabled to promote blue light emission while permitting the luminescent substance-containing hole transport layer 4 as an emission region.
As set out above, the hole-blocking layer 33 is provided to control the transport of the holes h. To this end, it is sufficient that the highest occupied molecular orbital (HOMO) level of the hole-blocking layer 33 is not higher than the HOMO level that is lower in energy between the HOMO levels of the hole transporting luminescent layer 4 b and the electron transport layer 2 , and that the lowest unoccupied molecular orbital (LUMO) level of the hole-blocking layer 33 is not lower than the LUMO level that is lower in energy and is not higher than the LUMO level that is higher in energy, between the LUMO levels of the hole transporting luminescent layer 4 b and the electron transport layer 2 . Thus, the invention is not limited to such an arrangement as set out before.
In the practice of the invention, the energy levels may not always be within such ranges as defined before, and the bathophenanthroline compound-containing layer per se may emit light or luminescence. In addition, the hole-blocking layer may be made of a built-up structure including a plurality of layers.
The hole-blocking layer 33 may be formed of the bathophenanthroline derivative and/or other material, and its thickness may be changed within a range permitting its function to be maintained. More particularly, the thickness is preferably within a range of 1 Å to 1,000 Å (0.1 nm to 100 nm). If the thickness is too small, the hole blocking ability becomes incomplete, so that the re-combination region is liable to extend over the hole transport layer and the electron transport layer. On the contrary, when the thickness is too large, light emission may not occur due to the increase in film resistance.
The organic EL device 21 is made by use of a vacuum deposition apparatus 11 shown in FIG. 7 . The apparatus 11 has therein a pair of support means 13 fixed below an arm 12 . A stage mechanism (not shown) is provided between the fixed support means 13 so that a transparent glass substrate 6 can be turned down and a mask 22 can be set as shown. Below the glass substrate 6 and the mask 22 , a shutter 14 supported with a shaft 14 a is provided, below which a given number of deposition sources 28 are further provided. The deposition sources are heated by means of a resistance heating system using an electric power supply 29 . For the heating, an EB (electron beam) heating system may also be used, if necessary.
In this apparatus, the mask 22 is for pixels, and the shutter 14 is for deposition materials. The shutter 14 is able to rotate about the shaft 14 a and has the function of intercepting a deposition stream of a material depending on the sublimation temperature of the deposition material.
FIG. 8 is a plan view showing a specific example of the organic EL device fabricated by use of the vacuum deposition apparatus. More particularly, ITO transparent electrodes 5 each with a size of 2 mm×2 mm are vacuum deposited on a glass substrate 6 with a size, L, of 30 mm×30 mm by means of the vacuum deposition apparatus in a thickness of about 100 nm, followed by vacuum deposition of SiO 2 30 over the entire surface thereof and etching in a given pixel pattern to form a multitude of openings 31 . In this way, the transparent electrodes 5 are, respectively, exposed. Thereafter, the respective organic layers 4 , 33 , 2 and a metal electrode 1 are successively formed through a deposition mask 22 of SiO 2 on each 2 mm×2 mm emission region (pixel) PX.
Using the vacuum deposition apparatus 11 , a large-sized pixel may be singly formed, aside from the device having a multitude of pixels as shown in FIG. 8 .
In this way, when the organic layer 33 is formed in order to improve the efficiency of the electron-hole re-combinations in the emission region, there can be obtained an organic EL device that is stable and high in brightness, can be driven at a low voltage and has the hole transporting luminescent layer 4 . As will be described in more detail, it is enabled to obtain a brightness of not smaller than 10,000 cd/m 2 by DC drive and a peak brightness, calculated as DC, of not smaller than 55,000 cd/m 2 by pulse drive at a duty ratio of {fraction (1/10)} with respect to blue light emission.
The transparent electrode, organic hole transport layer, organic hole-blocking layer, organic electron transport layer and metal electrode of the electroluminescent device may, respectively, have a built-up structure made of a plurality of layers.
The respective organic layers of the electroluminescent device may be formed not only by vacuum deposition, but also other film-forming techniques using sublimation or vaporization, or a technique of spin coating, casting or the like.
The hole transporting luminescent layer of the electroluminescent device may be formed by co-deposition of a small amount of molecules in order to control emission spectra of the device, and may be, for example, an organic thin film containing a small amount of an organic substance such as a perylene derivative, a coumarin derivative or the like.
Usable hole transport materials include, aside from benzidine or its derivatives, styrylamine or its derivatives and triphenylmethane or its derivatives, porphyrin or its derivatives, triazole or its derivatives, imidazole or its derivatives, oxadiazole or its derivatives, polyarylalkanes or derivatives thereof, phenylenediamine or its derivatives, arylamines or derivatives thereof, oxazole or its derivatives, anthracene or its derivatives, fluorenone or its derivatives, hydrazone or its derivatives, stilbene or its derivatives, or heterocyclic conjugated monomers, oligomers, polymers and the like such as polysilane compounds, vinylcarbazole compounds, thiophene compounds, aniline compounds and the like.
More particularly, mention is made of α-naphthylphenyldiamine, porphyrin, metal tetraphenylporphyrins, metal naphthalocyanines, 4,4′,4″-trimethyltriphenylamine, 4,4′,4″-tris(3-methylphenylphenylamino)triphenylamine, N,N,N′,N′-tetrakis(p-tolyl)-p-phenylenediamine, N,N,N′,N′-tetraphenyl-4,4′-diaminobiphenyl, N-phenylcarbazole, 4-di-p-tolylaminostilbene, poly(paraphenylenevinylene), poly(thiophenevinylene), poly(2,2′-thienylpyrrole) and the like, although not limited thereto.
Usable electron transport materials include quinoline or its derivatives, perylene or its derivatives, bistylyl or its derivatives, pyrazine or its derivatives, and the like.
More specifically, mention is made, for example, of 8-hydroxyquinoline aluminium, anthracene, naphthalene, phenanthrene, pyrene, chrysene, perylene, butadiene, coumarin, acridine, stilbene, or derivatives thereof.
The materials used as the anode electrode or cathode electrode of the electroluminescent device are not limitative in types.
The cathode electrode material should preferably be made of a metal whose work function from a vacuum level of an electrode material is small in order to efficiently charge electrons. There may be used, aside from an aluminium-lithium alloy, low work function metals such as, for example, aluminium, indium, magnesium, silver, calcium, barium, lithium and the like, singly or in the form of alloys with other metals for enhancing the stability thereof.
In order to take out organic electroluminescence from the side of the anode electrode, ITO is used as a transparent anode electrode in examples appearing hereinafter. Nevertheless, there may be used electrode materials, which have a great work function from the vacuum level of an anode electrode material and include, for example, gold, a stannic oxide-antimony mixture, a zinc oxide-aluminium mixture or the like, so as to efficiently charge holes.
The substrate 2 may not be limited to a glass substrate, but may be made of an opaque material. More particularly, there may be used, for example, a silicon substrate, a Cr substrate, or a substrate made of glass, on which a metal is formed by vacuum deposition. Where a substrate made of an opaque material is used, it is preferred that the upper surface of an organic EL device (i.e. the side of the cathode electrode) is formed of a transparent or translucent material so that electroluminescence is picked out to outside. ITO may be used for this purpose, for example.
There can be made an organic electroluminescent device for full color or multi-color, which is capable of emission of primaries of R, G and B, by proper choice of luminescent materials, not to mention an organic electroluminescent device for monochrome. Besides, the organic electroluminescent device of the invention is usable not only for display, but also for light source along with its application to other optical use.
It will be noted that the organic electroluminescent device may be sealed with germanium oxide or the like so as to enhance the stability thereof by suppressing the influence of oxygen or the like in air, or may be driven under conditions drawn to vacuum.
Second Embodiment
FIG. 9 is a schematic sectional view showing an essential part of an organic EL device according to a second embodiment of the invention. An organic EL device 22 of this embodiment differs from that of FIG. 1 in that the hole transporting luminescent layer 4 b is formed on the ITO transparent electrode 5 so that the hole transporting luminescent layer is formed as a single layer.
Third Embodiment
FIG. 10 is a schematic sectional view showing an essential part of an organic electroluminescent device according to a third embodiment of the invention.
An organic EL device 23 of this embodiment differs from that of FIG. 1 in that a hole transport layer (serving also as a hole transporting luminescent layer) 4 a is formed on the ITO transparent electrode 5 , and thus, the hole transporting luminescent layer is formed as a single layer, like the second embodiment.
The invention is described in more detail by way of examples.
Example 1
The specific arrangement of an organic electroluminescent device 21 in this example is described based on the fabrication method thereof.
An ITO transparent electrode 5 having a film thickness, for example, of about 100 nm was formed on a 30 mm×30 mm glass substrate 6 , followed by masking regions other than 2 mm×2 mm emission regions by deposition of SiO 2 to obtain a cell for making an organic electroluminescent device.
m-MTDATA (4,4′,4″-tris(3-methylphenylphenylamino)-triphenylamine of the structural formula indicated in FIG. 11) was deposited on the ITO transparent electrode 5 , as a hole transporting luminescent layer 4 a , at a deposition rate of 0.2 to 0.4 nm/second in vacuum in a thickness of 30 nm according to a vacuum deposition method.
Next, α-NPD (α-naphthylphenyldiamine of the structural formula indicated in FIG. 12) was formed on the hole transporting luminescent layer 4 a , as a hole transporting luminescent layer 4 b , by vacuum deposition (deposition rate: 0.2 to 0.4 nm/second) in a thickness of 53 nm, thereby forming a luminous hole transport layer 4 having a double-layered structure.
Thereafter, a bathophenanthroline derivative of the general formula indicated in FIG. 2, e.g. an o-methylphenyl-bathophenanthroline (i.e. a bathophenanthroline derivative (of the structural formula 2 indicated in FIG. 4 (Compound No. 29) attached with a methylphenyl group at the 2 and 9 positions of 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline) was vacuum-deposited on the hole transport layer 4 , as a hole-blocking layer 33 , in a thickness of 15 nm (deposition rate: 0.2 to 0.4 nm/second).
Subsequently, Alq 3 (8-hyroxyquinoline aluminium of the structural formula indicated in FIG. 13) serving as an electron transport layer 2 was deposited on the hole-blocking layer 33 in a thickness of 20 nm, followed by vacuum deposition of Al-Li (aluminium-lithium alloy with a Li concentration of about 1 mol %) in a thickness of about 0.5 nm and Al in a thickness of 200 nm as a cathode electrode 1 , thereby obtaining a blue-emitting organic EL device 21 shown in FIG. 1 .
The characteristic properties of the organic EL device made in this example were measured, revealing that the maximum emission wavelength (absorption peak) was at about 450 nm and the coordinates on the CIE chromaticity coordinates were at (0.15, 0.16). Thus, a good blue emission was obtained.
It was apparent from the shape of emission spectra that the emission resulted from the hole transporting luminescent layer 4 b (see FIG. 1) made of α-NPD.
Example 2
The organic EL device of Example 2 is described on the basis of its fabrication method.
With the organic EL device 23 of this example, an about 100 nm thick ITO transparent electrode 5 was initially formed on a 30 mm×30 mm glass substrate, followed by masking regions other than 2 mm×2 mm emission regions by vacuum deposition of SiO 2 to obtain a cell for making an organic electroluminescent device.
m-MTDATA (4,4′,4″-tris(3-methylphenylphenylamino)-triphenylamine of the structural formula indicated in FIG. 11) was deposited on the ITO transparent electrode 5 , as a hole transporting luminescent layer 4 a , in vacuum in a thickness of 50 nm (deposition rate of 0.2 to 0.4 nm/second) according to a vacuum deposition method, thereby forming the hole transporting luminescent layer as a single layer.
Next, phenylbathophenanthroline of the formula indicated in FIG. 3 (i.e. a phenanthroline derivative attached with a phenyl group at the 2 and 9 positions of 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline) was vacuum-deposited, as a hole-blocking layer 33 , in a thickness, for example, of 20 nm (deposition rate of 0.2 to 0.4 nm/second)
Subsequently, Alq 3 (8-hyroxyquinoline aluminium of the structural formula indicated in FIG. 13) serving as an electron transport layer 2 was deposited in a thickness of 30 nm, followed by vacuum deposition of Al-Li (aluminium-lithium alloy with a Li concentration of about 1 mol %) in a thickness of about 200 nm as a cathode electrode 1 , thereby obtaining an organic EL device 23 shown in FIG. 10 .
The characteristic properties of the organic EL device made in this example were measured, revealing that the maximum emission wavelength (absorption peak) was at 500 nm and the coordinates on the CIE chromaticity coordinates were at (0.22, 0.35). Thus, a good blue emission was obtained.
The brightness at a current density of 100 mA/cm 2 was at 2,200 cd/m 2 .
Example 3
The organic EL device of Example 3 was described based on its fabrication method.
For making an organic EL device 23 of this example, an ITO transparent electrode 5 was formed on a 30 mm×30 mm glass substrate 6 in a thickness, for example, of about 100 nm, followed by masking regions other than 2 mm×2 mm emission regions by vacuum deposition of SiO 2 to obtain a cell used to make an organic electroluminescent device.
m-MTDATA (4,4′,4″-tris(3-methylphenylphenylamino)-triphenylamine of the structural formula indicated in FIG. 11) was deposited on the ITO transparent electrode 5 , as a hole transporting luminescent layer 4 a , in vacuum in a thickness of 50 nm (deposition rate: 0.2 to 0.4 nm/second) according to a vacuum deposition method, thereby forming the hole transporting luminescent layer as a single layer.
Next, methylphenylbathophenanthroline of the structural formula 2 indicated in FIG. 4 (Compound No. 29) (i.e. a phenanthroline derivative attached with an o-methylphenyl group at the 2 and 9 positions of 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline) was vacuum-deposited, as a hole-blocking layer 33 , in a thickness, for example, of 20 nm (deposition rate: 0.2 to 0.4 nm/second).
Subsequently, Alq 3 (8-hyroxyquinoline aluminium of the structural formula indicated in FIG. 13) serving as an electron transport layer 2 was deposited in a thickness of 30 nm, followed by vacuum deposition of Al-Li (aluminium-lithium alloy with a Li concentration of about 1 mol %) in a thickness of about 200 nm as a cathode electrode 1 , thereby obtaining an organic EL device 23 shown in FIG. 10 .
The characteristic properties of the organic EL device made in this example were measured, revealing that the maximum emission wavelength (absorption peak) was at 450 nm and the coordinates on the CIE chromaticity coordinates were at (0.17, 0.15). Thus, a good blue emission was obtained.
The brightness at a current density of 100 mA/cm 2 was at 1,100 cd/m 2 .
Example 4
The organic EL device of Example 4 is described on the basis of its fabrication method.
With the organic EL device 23 of this example, an about 100 nm thick ITO transparent electrode 5 was initially formed on a 30 mm×30 mm glass substrate 6 , followed by masking regions other than 2 mm×2 mm emission regions by vacuum deposition of SiO 2 to obtain a cell for making an organic electroluminescent device.
m-MTDATA (4,4′,4″-tris(3-methylphenylphenylamino)-triphenylamine of the structural formula indicated in FIG. 11) was deposited on the ITO transparent electrode 5 , as a hole transporting luminescent layer 4 a , in vacuum in a thickness of 50 nm (deposition rate of 0.2 to 0.4 nm/second) according to a vacuum deposition method, thereby forming the hole transporting luminescent layer as a single layer.
Next, dimethylphenylbathophenanthroline of the structural formula 3 indicated in FIG. 5 (i.e. a phenanthroline derivative attached with an o-dimethylphenyl group at the 2 and 9 positions of 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline) was vacuum-deposited, as a hole-blocking layer 33 , in a thickness, for example, of 20 nm (deposition rate of 0.2 to 0.4 nm/second).
Subsequently, Alq 3 (8-hyroxyquinoline aluminium of the structural formula indicated in FIG. 13) serving as an electron transport layer 2 was deposited in a thickness of 30 nm, followed by vacuum deposition of Al-Li (aluminium-lithium alloy with a Li concentration of about 1 mol %) in a thickness of about 200 nm as a cathode electrode 1 , thereby obtaining an organic EL device 23 shown in FIG. 10 .
The characteristic properties of the organic EL device made in this example were measured, revealing that the maximum emission wavelength (absorption peak) was at 440 nm and the coordinates on the CIE chromaticity coordinates were at (0.16, 0.15). Thus, a good blue emission was obtained.
The brightness at a current density of 100 mA/cm 2 was at 1,030 cd/m 2 .
As will be apparent from the above examples, the organic EL devices obtained in Examples 1 to 4 of the invention, respectively, have the bathophenanthroline derivative-containing hole-blocking layer 33 interposed between the hole transporting luminescent layer 4 a and/or 4 b and the electron transport 2 . Accordingly, the electron-hole re-combination in the hole transport layer becomes satisfactory and can serve as a luminescent layer, thereby ensuring stable emission in a high efficiency.
Not only blue emission, but also bluish green emission was possible, along with red emission through doping and control in chromaticity by doping.
As will be apparent from these examples, even though existing materials are used, an organic EL device that has excellent chromaticity and ensures blue emission in high brightness can be made. Thus, a great possibility and shortage in time can be realized with respect to the development of materials for the device. In addition, it is believed that these examples indicate indices to the design of novel luminescent materials and electron transport materials.
Once again, in the practice of the invention, a bathophenanthroline derivative of the afore-indicated general formula is contained in a portion contacting a main emission region (especially, a bathophenanthroline derivative-containing hole-blocking layer is interposed between a hole transporting luminescent layer and an electron transport layer). Accordingly, using an organic electroluminescent device comprising a hole transport layer serving as a luminescent layer that has been considered difficult in realizing such an arrangement due to the absence of non-luminescent, excellent electron transport materials, stable emission of a high brightness can be obtained in a high efficiency. This is particularly remarkable with respect to blue emission, and it is possible to obtain a peak brightness of not lower than 10,000 cd/m 2 by DC drive and a peak brightness of not lower than 55,000 cd/m 2 , calculated as DC, by pulse drive at a duty ratio of {fraction (1/100)}. | An organic electroluminescent device has a single hetero structure comprising, on a glass substrate, an ITO transparent electrode, a hole transport layer, an electron transport layer and a metal electrode superposed in this. order wherein a hole-blocking layer containing a bathophenanthroline derivative of the following general formula is interposed between the hole transport layer and the electron transport layer. In this way, the electron-hole-re-combination in the hole transporting luminescent layer can be promoted. General Formula of Bathophenanthoroline Derivative:
wherein X and Y may be the same or different and independently represent a hydrogen atom except the case where a hydrogen atom is at the 2 or 9 position, a substituted or unsubstituted alkyl group except the case where a methyl group is at the 2 or 9 position, a substituted or unsubstituted cycloalkyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted amino group, a halogen atom, a nitro group, a cyano group or a hydroxyl group provided that at least one of these groups is contained at an arbitrary position. | 2 |
BACKGROUND OF THE INVENTION
The invention relates to a device for the multi-channel measurement of weak variable magnetic fields having field strengths below 10 -10 T, and in particular below 10 -12 T. The device contains a superconducting quantum interference device in each channel, and a gradiometer consisting of superconducting coils and superconducting connecting elements between the quantum interference device and the gradiometer. There is also a coupling transformer and connecting lines, in addition to electronic equipment for the evaluation, processing and presentation of the information obtained at the quantum interference devices. The invention also relates to a method for manufacuturing this measurement device.
The use of superconducting quantum interference devices, which are generally referred to as "SQUIDs" (abbreviation for "Superconducting Quantum Interference Devices), for the measurement of very weak magnetic fields is generally known ("J. Phy. E:Sci. Instrum.", Vol. 13, 1980, Pages 801 to 813; "IEEE Transactions on Electron Devices", Vol. ED-27, No. 10, October 1980, Pages 1896 to 1908). The preferred field of application for these devices is medical engineering and in particular magnetocardiography and magnetoencephalography. The magnetic cardiac or brain waves that occur in these sectors have field strengths that are located in the range from 50 pT to 0.1 pT ("Biomagnetism-Proceedings, Third International Workshop on Biomagnetism, Berlin 1980", Berlin/New York 1981, Pages 3 to 31).
A device for the measurement of biomagnetic fields of this kind includes the following principal components:
1. A SQUID, acting as a current sensor;
2. A flux transformer, a coil arrangement acting as a field-to-current transducer for sensing the field;
3. Electronic devices for collecting and processing signals;
4. Screening for the geomagnetic field and external interference fields; and
5. A cryogenic system for the superconducting components.
Measuring devices of this type are known (S.H.E. Corporation, San Diego, USA/S.H.E. GmbH, D-5100 Aachen).
In corresponding measurement devices with a one-channel design, the magnetic field to be investigated is coupled inductively through a coil arrangement made of superconducting wire into a circuit consisting of a radio-frequency (RF) SQUID with one Josephson contact. Gradiometers of the first or higher orders are constructed by combining one sensor coil with one or more compensation coils. With gradiometers of this type, it is possible, with the right kind of manual adjustment, to suppress almost entirely the three components of a homogenous magnetic field in the vicinity of the coils and/or the portion of such field with homogenous gradient. Also, the biomagnetic near field, which is still strongly non-uniform in the vicinity of the gradiometer, can be selectively obtained. The RF SQUID is also inductively coupled with a tank circuit, whose high-frequency voltage is modulated in phase or amplitude by the input signal. Generally, the operating point of the RF SQUID is maintained by negative feedback through an additional compensation coil, and the compensation current is used as a signal to be evaluated electronically.
The RF SQUIDs used in these units have a characteristic noise signal (cf., for example, "SQUID Superconducting Quantum Interference Devices and Their Applications", Berlin/New York 1977, Pages 395 to 431). Therefore, to measure the above-mentioned extremely weak magnetic fields, it is necessary to compute an average value for the signal at the individual measuring points with the aid of a large number of individual measurements. To obtain a spatial field distribution, it is necessary to take measurements one after the other at various points within the area to be investigated. In a measurement procedure of this type the field data will not remain coherent over the requisite measuring time, and, in addition, measuring times that are unacceptable for clinical purposes will occur.
To overcome these problems a multi-channel measurement device has been used instead of the familiar one-channel device. In the multi-channel device each channel has an RF SQUID, a tunable superconducting gradiometer and connecting elements between the SQUID and the gradiometer, which includes a coupling transformer and leads. Substantial time is lost in the utilization of this device, however, because the individual channels must be tuned to each other. Typically the gradiometer and the SQUID with its coupling transformer, are each arranged on their own carrying substrate and are connected with one another via detachable leads. This kind of connection, however, does not have the possibility of providing a constant tuning of the respective flux transformer in advance. Instead, it is necessary prior to every measurement to adjust all the channels. This adjustment can be difficult and time consuming because all the channels interact with one another. In addition, mutual interference of the RF circuits is unavoidable in this arrangement. If the gradiometer is dispensed with, an RF screening can, however, be achieved (cf. for example, "Physica", Volume 197,B, 1981, Pages 29 and 30). But even if an RF decoupling can be provided in some other way, the above-mentioned tuning problem remains.
A measurement device with three RF SQUIDs and only one tank circuit on a common substrate is disclosed in the publication "Cryogenics", December 1981, Pages 707 to 710. However, there are technical problems with this device. All the signal channels are combined into one high-frequency channel which provides the possibility of mutual interference. Additionally, the individual SQUID elements must be tuned to one another with regard to their critical current. Finally, the maximum number of elements that can be controlled in practice is therefore believed to be about 10.
In addition to the RF SQUIDs, each with a Josephson contact, that have been described above, direct current (DC) SQUIDs which include two Josephson contacts are also known. These DC SQUIDs can be designed so that they have an extremely small noise signal ("IEEE Transactions on Magnetics", Vol. MAG-17, No. 1, January 1981, Pages 395 to 399). The use of a modularly constructed system with 5 SQUIDs of this type for the measurement of biomagnetic fields is suggested. However, even though this device eliminates the problem of mutual RF interference, the above-mentioned tuning problem still exists.
SUMMARY OF THE INVENTION
The object of the present invention is to use DC SQUIDs to improve the device suggested above for the multi-channel measurement of weak variable magnetic fields so that it can be used to obtain the spatial distribution of biomagnetic fields within reasonable measuring times, while ensuring a substantial coherence of the field data.
This object is accomplished, according to the invention, by providing a common rigid substrate for DC SQUIDs and the planar-designed gradiometer coils associated with them, as well as for the superconducting connecting elements, with the gradiometer coils and the connecting elements being arranged at one or more planes, as thin-film structures.
Using this design for the measurement device permits parallel or simultaneous registration of the field values from various locations with the aid of an array of superconducting gradiometer coils, which are connected with a corresponding array of DC SQUIDs to form a rigid system. This allows the measuring time to be advantageously reduced in accordance with the number of channels. In addition, only a single adjustment is necessary when thin-film structures are used.
In general, the invention features, in one aspect, a device for the multi-channel measurement of weak variable magnetic fields with field strengths below 10 -10 T, which contains in each channel a superconducting quantum interference device (SQUID), a gradiometer having superconducting coils and superconducting connecting elements between the quantum interference device and the gradiometer, for the coupling transformer and leads, and which, in addition, includes electronic equipment for the evaluation, processing and presentation of information obtained at the quantum interference devices, in which a common rigid substrate is provided for direct-current superconducting quantum interference devices, planar-designed gradiometer coils that are associated with them and superconducting connecting elements, wherein the gradiometer coils and the connecting elements are arranged as thin-film structures on one or more planes.
In preferred embodiments of the measurement device the direct-current superconducting quantum interference devices are deposited on a common carrier chip which is rigidly mounted to the carrying structure; the substrate includes a single carrying part for the gradiometer coils, and connecting elements and the carrier chip of the direct-current superconducting quantum interference devices; all of the gradiometer coils are deposited on a common face of the substrate next to one another; the substrate is composed of a plurality of parts; the substrate includes two carrying parts wherein each of the parts are equipped with a gradiometer of the first order; the substrate includes quartz on silicon parts; the gradiometer coils are arranged as an array of detecting coils and as an array of compensation coils on the common substrate; the detecting coils have a different number of windings and different surface areas as compared with the associated compensation coils; the detecting coils and the compensation coils are arranged on different parallel faces of the substrate; the direct-current superconducting quantum interference devices are mounted on a face of the substrate, wherein the face lies in a plane other than that of the faces on which the gradiometer coils are deposited; the connections between the gradiometer coils are located on parallel faces, and are formed by thin-film conductors running between edges of the faces; the connections between the gradiometer coils and the direct-current superconducting quantum interference devices are formed by thin-film conductors running between the edges of the faces carrying these parts; the connection of the superconducting conductor elements to the edges is formed by soldering joints with superconducting material in grooves; the edges that include the grooves are beveled; dimensions (diameter D) of the individual gradiometer coils are adjusted to the closest magnetic field source to be detected, and means are provided for combining signals of individual gradiometer coils into a common signal from a group of gradiometer coils, depending on the distance of the magnetic field source to be detected in each case; in order to combine signals of individual gradiometer coils the corresponding channels in an electronic sytem for evaulation and processing of information obtained at the quantum interference devices, are interconnected; the carrying chip is fastened indirectly to the carrying structure by means of an intermediate carrier; and the intermediate carrier has slits in the area of the superconducting conductor terminals.
In general, the invention features, in another aspect, a method for the manufacture of a measurement device for the multi-channel measurement of weak variable magnetic fields with field strengths below 10 -10 T, which contains in each channel a superconducting quantum interference device (SQUID), a gradiometer having superconducting coils and superconducting connecting elements between the quantum interference device and the gradiometer, with a coupling transformer and leads, and which, in addition, includes electronic equipment for the evaluation, processing and presentation of information obtained at the quantum interference devices, in which a common substrate is provided for direct-current superconducting quantum interference devices, planar-designed gradiometer coils that are associated with them, and superconducting connecting elements, wherein said gradiometer coils and said connecting elements are arranged as thin-film structures on one or more planes, wherein the method includes the steps of depositing the gradiometer coils together with the leads that interconnect to one another and run to the direct-current quantum interference devices located on a carrier chip, on the substrate by planar-lithography techniques, forming the direct-current quantum interference devices on the carrier chip, and connecting the carrier chip with the direct-current quantum interference devices.
Other features and advantages of the invention will be apparent from the following detailed description and from the claims.
For a full understanding of the present invention, reference should now be made to the following detailed description of the invention and to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows diagrammatically a preferred embodiment of the measurement device of the invention.
FIG. 2 is a diagram of a substrate for this device, which shows the location of the SQUIDs and gradiometers.
FIGS. 3 and 4 show a top view and cross-sectional view, respectively, of a carrier for a corresponding SQUID chip.
FIG. 5 shows diagrammatically an alternate design for a device in accordance with the invention.
FIGS. 6 and 7 are detailed partial diagrammatic views of the measurement device, showing a connection on its strip connectors.
DETAILED DESCRIPTION
Referring to FIG. 1, a predetermined number N of parallel measuring channels has been provided for the measurement device. In this case, each channel contains a superconducting gradiometer 2, a DC SQUID 4 equipped with two Josephson contacts 3, a superconducting connecting element 5 to connect the gradiomeer with SQUID 4, preamplifier 6 that might, for example be cooled to the same level and a lock-in amplifier 7. The N unprocessed signals received from lock-in amplifiers 7 are then conducted to a common electronic data-processing and control system 8a, for further processing, and to output unit 8b for presentation. Feedback in the channels to the respective SQUIDs with the signals received from lock-in amplifiers 7 is indicated by dotted lines 9. The directions for the signal transmission are shown in the FIG. 1 by means of arrows along the corresponding lines.
As shown in FIG. 1, by means of broken lines, gradiometers 2, SQUIDs 4 and elements 5, that connect the gradiometers and the SQUIDs are arranged on common substrate structure 10a. In a similar manner, SQUIDs 4, with their associated thin-film transformers, are located on carrier chip 10b which is rigidly mounted on substrate 10a.
It is well known that for a specified distance between a gradiometer coil 2 and the magnetic field source to be detected by it, for example, in the heart, specific optimum dimensions exist for the gradiometer coils with regard to their sensitivity ("Journal of Magnetism and Magnetic Materials", Volume 22, 1981, No. 2, Pages 129 to 201). For field sources located at various distances, however, a change in the dimensions of the individual gradiometer coils is impossible from a practical point of view. Therefore, to be able to make an adjustment for the distance to the field source to be detected in each case, the signals generated at the individual gradiometer coils 2 of the measurement device can be advantageously combined. Accordingly, for example, in the case of the embodiment shown in FIG. 1, it is possible to combine the signals from any two or three of the gradiometer coils. The combination of the signals in this case should preferably occur in the area of electronic system 8a, which is common to all the coils, by means of appropriate connecting circuits.
In addition, it is advantageous to adjust the dimensions of each gradiometer coil (in the case of circular coils the diameter is adjusted) in relation to the distance of the closest magnetic field source to be detected. This adjustment is to obtain optimal local resolution. Thus, for example, for magnetoencephalographic a diameter of about 2 cm which is optimum for the movement of sources in the cerebral cortex. In order to permit an adjustment for magnetic field sources that lie deeper within the body, coil relationships are then set up by means of the above mentioned combination of signals from individual gradiometer coils, which substantially correspond to effective coil dimensions that are optimal for these greater distances between the magnetic field source and the coil.
Details of the arrangement of the gradiometers and SQUIDs on appropriate substrates are shown schematically in the other figures. The simplest arrangement of field sensors is an array of gradiometers of zero order, which is a level arrangement of adjacent flat cylindrical coils made of superconducting wire. Measurements made with an array of this type without additional compensation of external fields requires a relatively costly screening facility. However, this type of gradiometer array can be easily manufactured.
The gradiometers shown in FIGS. 2 and 5, have lesser requirements with regard to screening. While the gradiometer array shown in FIG. 2 is planar in design, FIG. 5 illustrates a gradiometer array arranged on two levels.
In FIG. 2 a planar series of gradiometers, also known as a gradiometer array, is deposited on planar substrate 11, which is for example, a quartz or silicon plate about 10 mm thick, 12 cm wide (b) and 20 cm long (1). This gradiometer array, which is designated 12, consists of an array 13 of detecting coils 14, an array 15 with a corresponding number of compensation coils 16, and appropriate leads 17. The figure shows only a few of the flat coils and leads. Each of arrays 13 and 15 consists, for example, of 4×5 individual superconducting flat coils with one winding each. The winding diameter D is roughly equivalent to the distance from the object to be investigated and therefore, might for example be a few centimeters. Since, as shown in the figure by a "+" and "-" sign, the direction of the windings of detection coils 14 is opposite to the direction of the windings of compensation coils 16, a crossover point 18 must be formed in each case, between the two arrays of flat coils, in leads 17.
It is possible to arrange detecting coils 14 and compensation coils 16 in a different arrangement than shown in FIG. 2. Thus, for example, if there is external compensation, the detecting coils can be enclosed by a ring formed by the individual compensation coils.
Array 15 of flat compensation coils can also be advantageously replaced by a smaller array of coils with a correspondingly increased number of windings. This can be accomplished, for example, by a lithographic process with the aid of an intermediate insulating layer.
Also located on substrate 11 is chip 19 which has a number of DC SQUIDs corresponding to the number of gradiometers, and including superconducting coupling transformers and modulation coils with terminals. In general, silicon is chosen for the chip material. The coupling transformers can be constructed in a convential manner as flat coils (cf. "IEEE Trans. Magn.", Vol. MAG-17, No. 1, January 1981. Pages 400 to 403). At terminal points 20, respective leads 17 which are used to conduct the field signals registered in the gradiometer coils, are connected by superconducting leads to these coupling transformers.
The signals picked up at the individual SQUIDs are then conducted over non-superconducting input/output lines 21 to multiple connector 23. Input/output lines 21 are connected to appropriate terminal points 22 on DC SQUID chip 19. The amplifiers of the respective channels are in turn connected to multiple connector 23. It is advantageous to use a material for substrate 11 and chip 19 which minimizes variations in thermal expansion. It is lso advantageous to use a soldering technique for the various connections. When such a chip carrier is used, it is also possible to exchange chips easily. An example of an embodiment of an appropriate chip carrier can be seen in the top view and lengthwise cross-section shown respectively in FIGS. 3 and 4. The chip carrier (designated as 25 in FIGS. 3 and 4) can be advantageously made of the same material as chip 26 that is mounted on it and which carries the SQUIDs and their thin-film transformers. Therefore, for example, the chip carrier can be made of silicon and plate 27, which carries the gradiometers, can be made of quartz. In order to relieve thermal stress at the terminals between strip conductors 28 which are deposited on the chip carrier, and strip conductors 29, which lead to the gradiometer coils and are located on carrying plate 27, chip carrier 25 has a series of deep notches 30 between the terminals. A resulting comb-like structure is produced on the terminal side, with teeth 31 formed between notches 30. Strip conductors 28 and 29 are connected with one another by means of solderings 32 on the free ends of teeth 31.
As can be seen from the lengthwise cross-section in FIG. 4, chip 26 is fastened to the underside 34 of the chip carrier 25 by solderings 33 of the strip conductors. An appropriate recess has therefore been provided in quartz plate 27. In addition, chip carrier 25, on its side facing away from the gradiometer coils, can project a bit beyond carrying board 27. This makes it possible to have on this side of carrier 25 a plug 35, to connect the SQUIDs to the appropriate amplifiers, which connects directly to the corresponding normally conducting strip conductors.
A measurement device having a carrier plate and manufactured in accordance with the invention is explained now with regard to FIG. 2. The first step in manufacturing this device is to construct, on carrying plate 11, planar gradiometer series 12 with detecting coils 14 and compensation coils 16 in the form of superconducting thin-film coil arrays. These arrays are made, for example, from lead, using a conventional planar lithographic process. During this initial step, it is also possible to manufacture leads 17, which connect the individual coils with one another, and crossover points 18, as a thin-film structure.
Independently of the above, the DC SQUID array may also be manufactured from niobium. In subsequent steps, the superconducting coupling transformers and modulation coils are deposited, in the form of a multi-layer thin-film structure, on silicon chip 19. Integrated circuit technology is used for this deposition. The coil terminals are made, for example, of lead. The DC SQUID chip is then firmly attached to carrying plate 11 on which the gradiometer array is located, in particular, with a conventional soldering process ("J. Electrochem. So.: Solid-State Science and Technology", April 1982, Pages 859 to 864). Soldering has the advantage that virtually no three-dimensional conductor strips are created. This is advantageous because three-dimensional conductor strips make it more difficult to adjust the gradiometers. Finally, gradiometers array 12 is connected with the DC SQUIDs located on chip 19. For this purpose soldered connections based on superconducting lead alloys my, for example, be used.
A single adjustment is then made for this arrangement of gradiometer array 12 and the DC SQUIDs on chip 19 that are associated with them on the carrying board 11. A laser beam is particularly well suited for this purpose; it is used to reduce the width of the individual coil windings.
When the gradiometer is designed as a thin-film structure on several planes with thin-film leads on a surface that is orthogonal, the adjustment can be easily made on this orthogonal surface. It is desirable to make the adjustment after test measurements in homogenous magnetic fields and homogenous gradient fields. It is advantageous to use planar gradiometers on several plane rather than planar constructed gradiometers because axially constructed gradiometers have better directional characteristic than planar gradiometers. An embodiment of an appropriate gradiometer structure of the first order can be seen in FIG. 5. In this figure some of the parts masked by the carrying substrate are indicated by broken lines. Carrying substrate 37 consists of parts 38 and 39 which are in the shape of right parallelepipeds rigidly attached to one another. The substrate holds gradiometer coils 40 and 41 or DC SQUID chip 42. The figure only shows a few of the gradiometer coils with their corresponding connecting leads. On front face 43 of part 38 of the substrate, which can be a quartz prism, detecting coils 40 are deposited. The detection coils can correspond to coils 14 in FIG. 2. The rear face 44 of this quartz prism carries compensation coil 41 corresponding to coils 16 in FIG. 2. Each detecting coil 40 is connected with its associatred compensation coil 41 on the opposite face, over the edges of the prism. This is accomplished by strip conductors 45 and 46, which are a few microns apart on faces 43 and 44 respectively. These conductors lead to edges 47 and 48 respectively of face 49 of quartz prism 38, which is orthogonal to faces 43 and 44. Additionally, strip conductors 50 extend over orthogonal face 49 between edges 47 and 48. Part 39 of the substrate, which is in the shape of a column and can also be made of a quartz prism, is rigidly attached to rear face 44 of part 38. This column-shaped prism has a cross-section adjusted to the size of DC SQUID chip 42. This chip may then be mounted, for example, on side 51 of column-shaped part 39 that is turned away from face 44. The DC SQUIDs of chip 42 are connected with the gradiometer coils via strip conductors 52 which correspond to strip conductors 45. These strip conductors run from individual detection coils 40 to edge 47 to face 43. At this edge conductors 52 are connected to strip conductors 53, which extend over orthogonal face 49 to edge 48 and correspond to strip conductors 50. By means of appropriate strip conductors 54, which are introduced on side face 55 of part 39, which lies in the same plane are orthogonal face 49, a connection is made between edge 48 and edge 45 and side 41 of prism 39 which carries chip 42. In addition to the arrangement of chip 42 on side 51, shown in FIG. 5, chip 42 can also be fastened to side face 55. In this case, strip conductor connections to edge 56 can be eliminated.
The arrangement of detection coils 40 and compensation coils 41 on two parallel levels of a substrate, as shown, for example, in FIG. 5, means that orthogonal levels are available. These levels can advantageously be used for introducing additional detection strips, for example, in thin-film technology, at these levels, with which the three vector components of the magnetic field can be determined for purposes of adaptive filtering (cf. "Rev. Sci. Instrum.", Vol. 53, No. 12, 1982, Pages 1815 to 1845, in particular Page 1836).
To reduce the expense of the lithography for the manufacture of the gradiometer, superconducting connections made of copper wire with Pb-In sheathing can be used when less mechanical stability is required. In this case fine soldering is possible at reinforced contacts.
The connection of strip conductors 52 with strip conductors 53 at edge 47 is accomplished advantageously according to a method shown in FIG. 6 for two strip conductor connections. Here, parts that are the same as in FIG. 5 are marked with the same reference number. Accordingly, at each predetermined connection point a groove 58 is cut perpendicularly into edge 47 between faces 43 and 49, before a thin film of the material of which the strip conductores are made is applied to the faces, including the walls of the groove. Next, conventional lithographing techniques are used to form the strip conductors by removing the superfluous portions of the applied films. In addition, edge 47 is slightly beveled to obtain sharper delimitations between coated and non-coated portions there. To improve the connection between strip conductors 52 and 53, it is possible, in addition, to solder to the bottom of the groove between the respective transition points to the parts deposited in grooves 58. In the Fig. solder joints of this kind are designated by 59. Superconducting lead-indium solder is particularly useful for this purpose.
It is also possible to manufacture the connections between strip conductors 50 and strip conductors 45 and 46, as well as the connections to edge 56.
FIG. 7 is a diagrammatic view of the transition of the strip conductors from part 38, which carries gradiometer coils 40 and 41, to part 39 which carries DC SQUID chip 42. The view shows a section through the corresponding portion of the embodiment shown in FIG. 5. In order to connect strip conductors 53 with strip conductors 54, they are first provided with connecting elements in grooves 62 and 63 respectively at respective edges 48 and 61, according to the process indicated in FIG. 6. Next sides 49 and 55 of parts 38 and 39 are placed together in such a way that the conducting portions in grooves 62 and 63 come in contact with one another. Then, one more soldering 64 is made, with, for example, a lead alloy, before which the film coatings in the grooves are strengthened by electroplating techniques.
In the embodiments of measurement devices shown in the figures, no effort has been made to portray any methods for screening the DC SQUIDs against magnetic interference fields, for reasons of clarity, and because appropriate methods are generally known. Thus, for example, in order to screen a SQUID chip, the SQUIDs on the chip can be surrounded individually by closed superconducting ring structures. It is also possible to coat the backside of the chip with superconducting material. If a special chip carrier is used, it, too, can be provided with an appropriate coating on its back. In this case the chip and its carrier can also be surrounded with a superconducting sheath that is closed up to an opening at the feed lines.
If gradiometers of the second order are to be constructed, then it is advantageous to put two individually adjusted units corresponding to part 38, shown in FIG. 5, together, and to connect their lines with one another over the edges in accordance with the process described with the aid of FIGS. 6 and 7.
Thus, for the construction of the substrate for the measurement device, the following 3 possibilities exist:
(a) A common carrying body is provided, on which the thin-film magnetometer arrays and the thin-film leads for a complete gradiometer of the 1st or 2nd order, including a SQUID chip on a chip carrier, are deposited.
(b) Two complete gradiometers of the 1st order are constructed according to the option described above under (a). Then they are put together in a mechanically rigid structure, in order to construct a gradiometer of the 2nd order out of two parts, which are also named as modules.
(c) Two rigid thin-film magnetometer arrays and a SQUID chip on a chip carrier are put together in a mechanically rigid structure and connected with one another by means of superconducting screened bundles of wire.
In the embodiments of the gradiometer coils that are shown in the figures, a circular design for the individual windings has been assumed. If necessary, however, to optimize the utilization of the surface and to minimize the mutual coupling, some design other than a circular one can be used.
There has thus been shown and described a novel device and method for the multi-channel measurement of weak variable magnetic fields and method for manufacturing said device which fulfills all the objects and advantages sought therefor. Many changes, modifications, variations and other uses and applications of the subject invention will, however, become apparent to those skilled in the art after considering the specification and the accompanying drawings which disclose preferred embodiments thereof. All such changes, modifications, variations and other uses and applications which do not depart from the spirit and scope of the invention are deemed to be covered by the invention which is limited only by the claims which follow. | An improved device for the multi-channel measurement of weak variable magnetic fields with fields strengths below 10 -10 T, having in each channel a superconducting quantum interference device (SQUID), a gradiometer consisting of superconducting coils and superconducting elements between the quantum interference device and the gradiometer, and a coupling transformer and connecting leads. In addition, the device includes electronic equipment for the evaluation, processing and presentation of the information obtained at the quantum interference elements. In order to use this measurement device to obtain spatial field distributions, particularly those of biomagnetic fields, during reasonable measuring times, with a substantial coherence among the field data, the invention provides for a rigid substrate on which direct-current quantum interference devices with associated planar-designed gradiometer coils and the superconducting connecting elements are arranged, and in which case the coils and the connecting elements are thin-film structures on at least one level. | 6 |
BACKGROUND OF THE INVENTION
The invention concerns a circuit for sensor controlled distance measurement wherein two linear image sensors are provided each having sensor elements. Means are provided for projecting onto the sensor elements segments of lines corresponding to images obtained separately from an object. Evaluator means are connected to the sensor elements for switching between two different switching states in dependence upon the exceeding of a reference charge in the sensor elements so as to digitalize the sensor signals. An evaluating circuit evaluates the digitalized sensor signals to control device means such as a photographic camera. A circuit of this kind is described in German patent application No. P2,838,647.2, incorporated herein by reference. There, the evaluators which are connected to the sensor elements and which undertake a digitalization of the sensor signals consist of portions of circuits of individual stages of a shift register, which undertakes relative position displacements of the sensor signals in a longitudinal direction of the image sensors.
SUMMARY OF THE INVENTION
It is an object of the invention to provide a very precise digitalization of the sensor signals and thus a precise evaluation of the maximum correlation of the sensor signals. This problem is solved in the circuit of the invention by connecting outputs of the evaluator means connecting to the individual sensor elements of the linear image sensors via transfer transistors to inputs of individual stages of two shift registers individually associated with the two image sensors. The last stage of each of the shift registers has an output which is back coupled to an input of its first stage and also is connected with an input of the evaluating circuit means for a serial release of evaluated sensor signals.
An advantage attainable with the invention is that the evaluators in the blocked state of the transfer transistors are completely separated from the stages of the shift registers. Therefore, independently of the parameters or characteristics of individual circuit parts of the shift register burdened with tolerances set by the manufacturer, they can be set back to predetermined voltage values. These voltage values usually are available with as great a precision as possible at the beginning of the integration times for the sensor elements at one or several circuit points of the evaluator circuits.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 illustrates a circuit diagram of a first embodiment of the invention;
FIG. 2 shows a portion of the circuit of FIG. 1;
FIG. 3 shows voltage-time diagrams for explanation of FIGS. 1 and 2;
FIGS. 4 through 6 show alternate designs of a portion of the circuit of FIG. 1;
FIG. 7 shows a second embodiment of the invention;
and
FIG. 8 shows a third embodiment of the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The circuit represented in FIG. 1 contains two linear image sensors 1 and 2 having sensor elements 11, 12-1n and 21, 22-2n. The image sensors 1, 2 are integrated upon a doped semiconductor body of a first conductivity type. If the sensor elements are realized as photodiodes, then the shaded rectangles represent regions arranged on an interface of the semiconductor body having a second conductivity type which is opposed to the first. The sensor elements 11-1n and 21-2n are connected via individually associated switching transistors T11-T1n and T31-T3 as well as T21-T2n and T41-T4n with a lead which is connected with a supply voltage U DD . The gate electrodes of the switching transistors T11-T1n and T21-T2n are in each case directed to a common lead, to which is supplied a clock pulse voltage φ 1, whereas the gate electrodes of the switching transistors T31-T3n and T41-T4n are connected with leads which are at a pulse voltage φ 2.
The sensor elements 11-1n and 21-2n are connected via the switching transistors T31-T3n and T41-T4n with the inputs of evaluators 31-3n and 41-4n.
A practical circuit design of the evaluators 31-3n and 41-4n is to be specified even more precisely with the use of FIG. 2. Further inputs of these evaluators are connected via common switching transistors T51 and T52, the electrodes of which are connected with a clock pulse voltage φ 3 to leads at a reference voltage U Ref . The evaluators 31-3n and 41-4n, in dependence upon the voltages supplied to them via the switching transistors T31-T3n and T41-4n, can assume one of two possible switching states. Their output signals S11-S1n and S21-S2n, which can be obtained at A, in each case correspond to the logic voltage level "1" or "0" according to the assumed switching state. They are supplied via transfer transistors T61-T6n and T71-T7n, the gate electrodes of which are provided with a common clock pulse voltage φ 5, to the inputs of the individual stages 51, 52-5n and 61, 62-6n of two shift registers 5 and 6 associated individually to the image sensors. These shift registers are preferably designed as two-phase dynamic shift registers. The shift register 5 displays two inputs which are connected with clock pulse voltages φ 1L and φ 2L, whereas the shift register 6 has two inputs to which the clock pulse voltage φ 1R and φ 2R are supplied. The output 5a of the stage 5n is connected on one side via a line 5b with the input of stage 51, and on the other side is connected to a first input of a logic circuit 8 which is arranged in an evaluating unit 7. The output 6a of the stage 6n is directed in a corresponding manner via a line 9 to the input of stage 61, and is connected on the other side with a second input of 8.
The logic circuit 8 has connected to it a counter 10, the output of which is connected via a memory 10a with the first input of a digital comparator 13 and via an electronic switch 14, with a memory 15. The output of the memory 15 is directed to a second input of the digital comparator 13.
A clock pulse generator 16 is provided with outputs for the clock pulse voltages φ 1 through φ 3 and φ 5. Via further outputs 17 and 18, the clock pulse voltages φ 1L and φ 2L as well as φ 1R and φ 2R are released, whereby a gate circuit 19 is arranged in series to the outputs 17 and, in series to the outputs 18, a gate circuit 20 is arranged. The control inputs of 19 and 20 are connected via lines 23 and 24 with control signals which are still to be specified more precisely. The clock pulse generator displays a further output 25, to which a further gate circuit 26 is arranged in series. This gate is controlled via a line 27 with a further control signal. The output 25 is connected with the input of a counter 28, the output of which is connected via an electronic switch 29 with a memory 30. The output 33 of the memory 30 is connected with a device 34 which is to be specified further below.
FIG. 2 shows a practical design of the evaluators 31-3n and 41-4n utilizing evaluator 31 as an example. It consists of a flip-flop circuit with the switching transistors T8 and T9 and the transistors T10 and T10' which are operated as switchable load elements. The source leads of T8 and T9 are connected via a common lead 35 to the reference potential of the circuit, and the drain leads of T10 and T10' are connected via a common lead to the supply voltage U DD . The input node of the evaluator 31 is designated 37, and the output node connected with output A is designated 38. Between the gate electrodes of T8 and T9 and the nodes 37 and 38 there exists a cross coupling. The gate electrodes of T10 and T10' are connected via a common lead with a clock pulse voltage φ 4. The circuit parts T11, 11 and T31 as well as T51, which are connected to the nodes 37 and 38, already described in FIG. 1.
The object distance measurement system used in this invention includes two optical devices shown as a single unit imager at 100 in FIG. 1 via which two separate images are created, the distance-dependent relative positions of which are evaluated. The light beams L1 in FIG. 1 thereby proceed from the object whose distance is to be determined. Via a first optical device, they project an image of the object onto the plane of the image sensor 1 which is positioned to receive a line segment of the image. In an analogous manner, the light beams L2, which are provided via a second optical device from the object, project a second image of the same onto the plane of the image sensor 2, which also is positioned to receive the line segment when the object is located at a predetermined distance, for example, at the distance "infinite". If the distance of the object changes with respect to the predetermined value, then the line segments which were projected onto the image sensors 1 and 2 are displaced correspondingly in the longitudinal direction of the image sensors. The size of the mutual displacement thereby represents a measurement for the actual distance of the object. In a similar method of distance measurement using the above-specified relative displacement of two images of the object, instead of linear image sensors surface related arrangements of photodiodes are provided, as known for example from the magazine "Electronics" of Nov. 10, 1977, pages 40, 42, 44, incorporated herein by reference.
The manner of operation of the circuit according to FIGS. 1 and 2 proceeds in connection with the pulse-time diagrams according to FIG. 3. If a trigger pulse is supplied to an input 39 of the clock pulse generator 16, then this releases first clock pulses φ 1 and φ 2. With this, the sensor elements such as 11, and the input nodes such as 37 of the evaluators, are set back to the supply voltage U DD via the transistors, for example, T11 and T31, connected to be conducting. A simultaneous starting clock pulse φ 3 switches T51 into the conducting state, so that the output node 38 is placed at the reference voltage U Ref . With disconnection of the clock pulse φ 1, charge carriers which are generated by means of the incident light beams L1, or respectively, L2 begin to collect in the sensor elements, for example, 11, whereby, a voltage drop arises in the sensor elements. The larger the optically generated charges which in each case have collected in the sensor elements 11-1n and 21-2n are, the more strongly the potential decreases at the associated input node, for example, 37 of the evaluator. The time span between the end of the clock pulse φ 1 to the point in time t1 and the predetermined end of the pulse φ 2 to the point in time t2 is designated as integration time. Only within this time span do optically generated charges collect in the sensor elements. After ending of the clock pulse φ 2 and after ending of the clock pulse φ 3, a clock pulse φ 4 from the clock pulse generator 16 is placed at the gate electrodes of T10 and T10', so that the flip-flop circuits of the evaluator are activated. At the output node, for example 38, for when at node 37 a potential drop occurs below the reference voltage U Ref , a voltage occurs which approximately corresponds to the supply voltage U DD (logic "1"). If on the other hand the voltage at node 37 does not fall below U Ref , then the node 38 proceeds to a potential which approximately corresponds to the reference potential at lead 35 (logic "0"). With this, each evaluator releases a digitalized sensor signal, for example S11, the value of which is dependent upon the attainment or non-attainment of a reference charge in the individual sensor elements which is present precisely when the potential at node 37 at point in time t2 approaches the potential of node 38 which was set back to the voltage U Ref . With the occurrence of a clock pulse φ 5 then, the digitalized sensor signal, for example S11, is supplied to the inputs of the associated stages for example 51, of the shift registers 5 and 6 and are stored in these registers.
Following this, the clock pulse generator 16 delivers clock pulse sequences φ 1L, φ 2L, φ 1R, and φ 2R which displace the information contained in the stages of the shift registers 5 and 6 by one step. Before the occurrence of the clock pulses 43 and 44 which belong to a clock pulse period TPL1, the sensor signal S1n appears at the output 5a. The clock pulses 43 and 44 displace the information S1n into the stage 51 and the information S1(n-1) to the output 5a, and so on. By means of the clock pulses 45 and 46 of the clock pulse period TPLn, finally after a complete information cycle, again the sensor signal S1n arrives at the output 5a. There follows a clock pulse period TPLz with the clock pulses 47 and 48, by means of which the sensor signal S1(n-1) appears at the output 5a. After a following blanking gap which is designated 49, the clock pulses 53 and 54 of the clock pulse period TPL1' displace the sensor signals again by one step further, so that S1(n-1) arrives at stage 51 and S1(n-2) is connected through to the output 5a.
In a first readout cycle Z1 which encompasses the clock pulse periods TPL1 through TPLn, therefore, the sensor signals S1n through S1 and again S1n are released serially at the output 5a. In a second read-out cycle Z2, which encompasses the clock pulse periods TPL1' and n-1 further clock pulse periods there proceeds a second serial release of all sensor signals of the image sensor 1, whereby the signals S1(n-1) through S1 and again S1n and S1(n-1) appear at 5a. Within the first read-out cycle Z1, the shift register 6 is also provided with n clock pulse periods TPR1 through TPRn, while the clock pulses 47 and 48 lack corresponding pulses. This has the result that at the beginning of Z2, the sensor signal S2n lies at the output 6a and the signal S1(n-1) lies at the output 5a.
With this, in the first read out cycle Z1, the signal pairs S1n and S2n, S1(n-1) and S2(n-1) and so on are read-out at 52 and 62 serially, in the second read-out cycle on the other hand, the signal pairs S1(n-1) and S2n, S1(n-2) and S2(n-1) and so on are read out. The serially read out information of the shift registers 5 and 6 are thus displaced with respect to one another in two consecutively following read-out cycles in each case one signal width. After n read out cycles, they then again have the same time related association as in cycle Z1. In FIG. 1, this displacement can be attained such that the gate circuit 20 is blocked via line 24 by an inhibit signal P24 during the appearance of the clock pulses 47 and 48, that is, between the clock pulse periods TPRn and TPR1'. In this time period, the gate circuit 26 can be opened via the control line 27 by an enable signal P27, so that one of the pulses 47 or 48 or a pulse derived from these appears at the output 25 as a displacement pulse P1 (not shown in FIG. 3). This displacement pulse P1 thereby characterizes the beginning of a new read-out cycle and a mutual displacement of the sensor signals which are read out serially at the outputs 5a and 6a in each case by one signal width.
The sensor signal pairs which were read out within a read-out cycle, for example Z1, are evaluated in the logic circuit 8 according to the exclusive OR function. Therefore, at the output 55 of 8, there always occurs an output pulse when the digital signals supplied on the input side via 5a and 6a coincide. If they do not coincide, then no output pulse is released from 8. The partial circuit 8 can however also be designed such that it only indicates the coincidence of two "1" signals or two "0" signals at its inputs by means of an output pulse. The counter 10, which before the start of each read-out cycle, (in the blanking intervals 49) is set back to zero, then counts the number of coincidences within one such cycle.
The counter 10 is connected to be operative only during a portion of each read-out cycle. This portion is determined by a pulse φ F at RS which is released from 16 to counter 10 at RS'. If one assumes that the counter 10 in the readout cycle Z1 counts the coincidences within the clock pulse periods TPR i through TPR k , whereby the difference k-1 amounts approximately to n/2 or 3n/4, then in the readout cycle Z2, it counts the coincidences within the clock pulse periods TPR' i+1 through TPR' k+1 . If one considers the pulses φ F1 and φ F2 in each case as "read-out windows", then the signals of the shift register 6 have been displaced in the window φ F2 with respect to the window φ F1 by a signal width to the left (FIG. 3). In the next read out cycle Z3, in which the corresponding pulses φ F3 encompasses the same clock pulse periods as in Z2, then the signals from 5 have been displaced in the "window" φ F3 by a signal width toward the right. If the "window" is generally displaced in the first read-out cycle Z1 and in the further read out cycle Z3, Z5, Z7 and so on by a clock pulse period length in each case to the right, then this corresponds to an alternating displacement of the sensor signal sequences available at 6a, or respectively, 5a in the window φ F in each case by a signal width to the left, or respectively, the right. Those pulses φ F which would encompass the evaluator signals which were derived from the line beginning and from the line end of one of the sensor element lines, simultaneously are suppressed by the clock pulse generator 16. Therefore it results that the "windows" φ F disconnect the evaluation of those sensor signals which were derived from the beginning and end segments of the projected line segments which are next to one another in exchanged association, so that they provide no information concerning the actual brightness curve along the line segment.
If the counter result which is supplied to the input 56 of the digital comparator 13 is larger than the digital signal which is present at its input 57, then the control inputs of the switches 14 and 29 are provided with a comparator signal, so that both switches transmit the signals at their inputs to the output in each case. After the counter result of the coincidences of the first information cycle Z1 is supplied as a first digital signal to the memory 15, and via this to the input 57 of the comparator, now only a counter result of a further information cycle Z1 is taken into the memory 15 which is larger than the largest in each case which was stored ahead of time. The displacement pulses P1, P2 (not shown is FIG. 3) and so on, which appear at the end of the information cycles Z1, Z2 and so on, are counted in the counter 28. Since switch 29 is activated synchronously with switch 14, it always transmits the count of the counter in each case from 28 to the memory 30 in the case of the appearance of a larger counter result in the counter 10. Thus, in memory 30, after n information cycles, the number of the displacement pulses Pi is stored which characterizes that information displacement between the sensor signals of the shift registers 5 and 6 wherein the largest number of coincidences occurs. In other words: the number of the shift pulses Pi which are stored in the memory 30 releases the relative displacement of the sensor signals circulating in the shift registers 5 and 6 whereby a maximum correlation of the sensor signals which are compared with one another exists. The blanking gaps 49 which were indicated in FIG. 3, which for example are required for the setting back in each case of the counter 10 to 0, are generated by means of a corresponding blocking of the gate circuits 19 and 20 via respective inhibit signals P23 and P24 on their control lines 23 and 24. The setting back is accomplished by applying a reset pulse from terminal RS of the clock pulse generator 16 to the terminal RS of the counter 10.
The digital signal appearing at output 33 of the memory 30 is supplied to a device 34 which can be conceived of as an indicating device, which, after a corresponding coding of the digital signal, delivers a digital or analog indication of the distance of the object. On the other hand, the device 34 could also consist of an essentially known adjustment device of a photographic or electronic camera, which sets the distance of a lens which is movable with respect to a focal plane such that the object is sharply imaged on this focal plane. A device of this kind is specified, for example, in German patent application No. P 2,813,915.3, incorporated herein by reference, and in the magazine "Electronics" of Nov. 10, 1977 on the pages 40 through 44, also incorporated herein by reference.
FIG. 4 shows a preferred circuit design of the sensor elements 11-1n and 21-2n as well as the adjacent circuit parts using as an example sensor element 11. Upon a doped semiconductor body 58, for example, of p-doped silicon, a thin electrically insulating layer 59, for example of SiO 2 , is provided. The image sensor 11 is designed as a photodiode which consists of the n-doped semiconductor region 60. This region simultaneously also forms the source region of the transistor T31. The gate of T31 is arranged on the insulating layer 59 and is designated 160. The drain region of T31 has the reference symbol 161. This region is connected on the one side via transistor T11 with a lead which is connected with the constant voltage U DD and is further connected with the input of the evaluator 31. The circuit parts T51 and A were already described with the use of FIG. 2.
FIG. 5 shows an alternative circuit to FIG. 4. According to this, the sensor element 11 consists of a MIS capacitor (metal-insulating layer-semiconductor-capacitor), which has a gate 165 arranged on the insulating layer 59. The gate 165 is, for example, prepared from highly doped polycrystalline silicon and lies at a clock pulse voltage φ K, under the influence of which a space charge region 166 forms in the semiconductor body 58. The further circuit parts of FIG. 5 correspond to the circuit parts of FIG. 4 which are provided with the same reference symbols, whereby the transistor T11 has a clock pulse voltage φ 1' fed thereto and the transistor T31 has a clock pulse voltage φ 2' fed thereto. The simultaneously starting clock pulses φ 1', φ 2' and φ K up to the point in time t1' bring about a setting back of the MIS capacitor in the region of the interface 58a of the semiconductor body 58 approximately to the value of the supply voltage U DD . At the point in time t1', in the MIS capacitor which is further provided with φ K, the integration time begins, during which optically generated charge carriers are collected. With the end of φ K at the point of time t2', also the end of the integration time is attained. Shortly before the point in time t2', a new clock pulse φ 2' is applied, so that a charge takeover from 166 to 161 can take place, indicated by the arrow 504 (FIG. 3). This charge takeover at the output of the evaluator brings about a corresponding change in potential. The clock pulse φ 1' must be disconnected before this charge takeover, as indicated in FIG. 3.
FIG. 6 differs from FIG. 5 since a photodiode 601 is arranged next to the MIS capacitor 165, 166, and indeed on the side turned away from T31. The gate electrode of T31 is connected with the pulse voltage φ 2', while the gate electrode of T11 is supplied with the clock pulse voltage φ 1'.
The capacitance of the sensor element 11 according to FIG. 5 is larger than the capacitance of the sensor element according to FIG. 4, whereas the capacitance of the sensor element 11 according to FIG. 6 is larger than that of the sensor element according to FIG. 5.
In FIG. 7, a second embodiment example of the invention is represented, whereby two circuits according to FIG. 1 are provided with a common evaluating part 7 and common device 34 which are connected to this. The components of the partial circuit arranged in FIG. 1 on the left side of the evaluating part 7 are provided in FIG. 7 with the same reference symbols. Thereby, the individual sensor elements 11, 12-1n in the longitudinal direction of the image sensor 1 are designed so narrow that they correspond approximately to half the dimension of the evaluator 31, 32-3n. In these evaluators, for the sake of simple representation, also the switching transistors T11, T31 as well as T61 and so on are included. The corresponding components of the second circuit according to FIG. 1 are provided in FIG. 5 in each case with reference symbols which are supplemented by a prime mark. As can be seen, the sensor elements 12-1n of the one image sensor are arranged in the gaps between the sensor elements 11', 12'-1n' of the other image sensor. In the case of this embodiment example, double the number of sensor elements can be housed upon a sensor length corresponding to FIG. 1, so that the resolution of the line segments projected onto the sensor elements is significantly greater than in FIG. 1. In order to prevent a mutual interference of the information cycle in the shift registers 5 and 5', alternatingly activatable electronic switches Sc and Sc' are provided, which alternately connect one of the outputs 5a and 5 a' with the one input of the logic circuit 8 and with the input of the corresponding first stage 51, or respectively, 51' of the shift registers. They are controlled by means of clock pulse voltages φ 6 and φ 6'. The individual clock pulse periods of φ 6 are separated from one another by means of intermediate periods which display the same length as the clock pulse period. Then the clock pulse periods of φ 6' fall together with these intermediate periods. The circuit represented in FIG. 7 is to be supplemented on the right side of the evaluating part 7 by a corresponding arrangement of two further image sensors and the evaluators associated to them and shift registers, whereby their sensor elements are also designed so narrow that they correspond to half the evaluator width, seen in the longitudinal direction of the image sensors.
Finally, FIG. 8 shows a circuit corresponding to FIG. 1, whereby the image sensors 1 and 2 are arranged next to one another, so that their sensor elements 11, 12-1n and 21, 22-2n are arranged in two lines which lie adjacent one another. The evaluators 31, 32-3n and 41, 42-4n in each case also contain the switching transistors T11, T21, T31 and T41, as well as T61, T71 and so on. This embodiment example can be drawn upon if the images of the object in each case are projected only by half onto the plane of the image sensors from 1 and 2, whereby the upper half of the one image falls upon the part of the focal plane which lies above the dividing line 66, while the lower half of the other image is projected on the part of the focal plane which lies under dividing line 66. The line segments which were evaluated by means of the image sensors 1 and 2 thereby lie at the boundaries in each case of the halves of the images, which are adjacent to the dividing line 66. Such image projection techniques is also specified in the German patent application No. P2,838,647.2, incorporated herein by reference.
The circuits specified and represented can with special advantage be entirely or partially monolithically integrated upon a doped semiconductor body. Thereby, the semiconductor body, for example 58, is designed preferably p-conducting and the remaining circuit structure is embodied in MOS n-channel engineering. The semiconductor body lies at a reference potential, whereby the stated voltages and potentials display a positive sign with respect to this in each case. In the case of an n-conducting semiconductor body and MOS p-channel engineering, these signs become negative. The embodiment examples which were specified and represented display stops in the region of the image sensors 1 and 2, in which apertures are provided through which an exposure of the sensor elements proceeds.
Although various minor modifications may be suggested by those versed in the art, it should be understood that we wish to embody within the scope of the patent warranted hereon, all such embodiments as reasonably and properly come within the scope of our contribution to the art. | A circuit for sensor controlled distance measurement is disclosed having two linear image sensors which are positioned to receive corresponding lines of two images derived from an object. The sensor signals are subjected to correlation measurements from which the distance of the object is determined. In the case of circuits of this sort, one endeavors to attain as exact and unfalsified a distance measurement as possible. For this purpose, the sensor signals are digitalized in evaluators, then read via transfer transistors into shift registers which undertake relative position displacements of the sensor signals in a longitudinal direction of the image sensors between individual signal cycles, and are subject to a correlation measurement. The circuit distinguishes itself in that the digital evaluation proceeds completely independently of parameters of the shift register and is thus carried out very precisely. Applications include photographic and electronic cameras. | 6 |
CLAIM FOR PRIORITY
[0001] This application claims the benefits of U.S. Provisional Application No. 60/380,827, filed on May 17, 2002, which is hereby incorporated by reference in its entirety.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The invention relates to a wheel bumper block, and more particularly to a pinless wheel bumper block capable of being readily relocated and rearranged.
[0004] 2. Description of the Related Art
[0005] Marine container shipping involves using standardized shipping containers to ship cargo. Shipping cargo in these standardized containers facilitates loading, unloading and storage at a port site. Once offloaded from a merchant vessel at the port site, the containers can be stored in terminals specifically laid out to temporarily house large quantities of these containers prior to distribution. The containers can be stored in the terminals in either of two ways. One way, is by stacking containers one on top of another and positioning these stacks of containers within the terminal. Such containers can be referred to as grounded containers. Alternatively, a container can be mounted onto wheeled semi-truck flatbeds or chassis and parked in individual parking stalls at the terminal. Such containers can be referred to as shipping or wheeled containers.
[0006] Because wheeled containers usually are not stacked, wheeled containers occupy more storage space than grounded containers. Thus, it is desirable to optimize limited storage area for wheeled containers by parking them close together, including, back-to-back and/or against walls, fences, or perimeters. To accurately position these wheeled containers as well as to avoid collision and damage, pinned wheel bumper blocks are generally used to delineate certain parking boundaries for wheeled containers. These bumper blocks are referred to as pinned wheel bumper blocks, because they have vertical pin holes adapted to receive steel rods or dowels that are either driven or drilled through the pin holes and into the underlying pavement. Generally, there is a clearance gap between the pin and the pin hole. To adequately secure the block and pin to each other, grout is added to the clearance gap of pin hole in the block. Without securing the pin in the block, the block and pin can become disengaged from one another when a backed-in wheeled container applies sufficient force to the block. Some conventional bumper blocks are also secured to the pavement using an adhesive to form a cementitious bond between the bottom of the concrete block and the pavement asphalt. Once the pinned blocks are installed in the desired pattern, typically at one end of the parking stalls, as shown for example in FIGS. 20 and 21, the wheeled container is backed into the parking stall until the wheels contact the pinned wheel bumpers, which indicates to the driver that the wheeled container is properly aligned. Because the wheel bumper is anchored to the ground by the above-described pins, it will remain in position, and not slide when contacted, bumped, or forced by the wheeled container.
[0007] These parking facilities, including terminals in marine container environments periodically require rearrangement to change the amount of space allocated between grounded container and wheeled container storage. Accommodating such changes may require rearrangement of an existing wheeled container parking configuration. Installing, removing and rearranging pinned wheel bumper blocks is labor intensive. When more grounded container space is needed, it is often necessary to remove pinned wheel bumper blocks from the pavement. When removing the blocks, the grouted pins are also removed from the underlying pavement structure. Thus, removing the blocks and pins damages the pavement structure and leaves holes in the surface, which can be hazardous and/or require repair. Furthermore, re-using the pinned wheel bumper block requires that the grouted pin be removed or extracted, which often can damage or destroy the block rendering it unusable. Additionally, although a compatible forklift can be used to transport the pinned wheel bumper blocks, because of the configuration of these blocks, as shown in FIGS. 17 - 19 , the blocks cannot be easily stacked for transport or storage during periods of non-use. This further increases the time required to rearrange wheeled parking stalls and storage of the unused blocks can take-up valuable storage space. What is needed is a wheel bumper block that can be readily installed, rearranged without damaging the underlying pavement structure or the wheel bumper itself and easily stored in a limited space during periods of non-use. As illustrated in FIGS. 17 - 19 , the pinned wheel bumper blocks typically are made of a precast, reinforced concrete block, 4 to 8 feet long, 12 inches wide, 7 inches high, and weigh approximately between 350 to 700 pounds. Because the pinned block is anchored to the ground by steel pins driven into the ground or underlying pavement and then grouted as described above, the block remains in position, particularly when the force of the wheeled container is applied against it. Where a single row of wheeled parking stalls is placed, for example, against a fence or building, these pinned wheel bumper blocks protect the adjacent structure from damage by preventing the container chassis from being backed beyond the limits of the parking stall. Where two rows of wheeled parking stalls are placed back-to-back, these pinned wheel bumper blocks separate the two rows by preventing container chassis from being backed into one another, as shown in FIGS. 20 and 21. Thus, the pins are important to fixedly secure the blocks in position and prevent the block from moving, shifting and/or tipping.
[0008] Finally, when product including, but not limited to bumper blocks, is transported using a forklift, the forklift should be of the type that can accommodate the lifting and transporting of a given load. If a forklift cannot accommodate the load, i.e., it is an out-of-gage load, then the forklift can be referred to as incompatible forklift and under such circumstances, a different forklift should be used, that is, one that can accommodate the load, which can be referred to as a compatible forklift.
[0009] Having to use different forklifts can be problematic because a compatible forklift would have to be obtained. As a result, what also is needed is a forklift adapter, which would allow using an incompatible forklift to lift and transport an out-of-gage load, including but not limited to a wheel bumper block. Such a forklift adapter would convert an incompatible forklift to a compatible forklift.
SUMMARY OF THE INVENTION
[0010] The invention solves the problems and overcomes the disadvantages of the prior art. For example, the invention accomplishes this by providing an anchorless wheel bumper block for use as a stop in a parking facility, such as in industrial or commercial trucking, warehousing distribution, intermodal facilities, rail yards, and equipment yards. The anchorless wheel bumper block includes a base that has a bottom surface, a top that has an upper surface, and a side extending around a perimeter of the block and between the bottom and upper surfaces. The bottom surface is disposed in a first plane, has a first length, and rests on a ground surface. The upper surface is disposed in a second plane, which is generally parallel to the first plane. A distance between the bottom and upper surfaces defines a height of the block, and the length is substantially greater than the height of the block. The block is in contact with and unattached to the ground surface in an in-use position and remains substantially in the in-use position when a wheeled unit contacts the block.
[0011] According to another aspect of the invention, a wheeled parking system including wheeled unit parking locations is provided. The wheeled parking system includes a ground surface in an original condition and an anchorless wheel bumper block for use as a stop. The block is disposed at an end of the wheeled unit parking location and prevents a wheeled unit from exiting the parking location. When the wheeled unit contacts the block, the block remains in substantially the in-use position. When the block is lifted from the ground surface and moved to a non-use position, the ground surface remains substantially in the original condition. The bumper block has a substantially flat and elongate shape and includes a base that has a bottom surface, a top extending from the base that has an upper surface, a side extending around a perimeter of the block and between the bottom and upper surfaces. The bottom surface rests unattached on the ground surface and the block is unattached to the ground surface in an in-use position. The bottom surface has a first size, and the upper surface has a second size, which is substantially equal to the first size.
[0012] In yet another aspect of the invention, a parking facility anchorless wheel bumper block is provided. The anchorless bumper block includes a bottom portion, a top portion, and a side extending around a perimeter of the block between the bottom and top portions. The bottom portion is disposable on a ground surface in an in-use location adjacent a wheeled unit parking location. The bottom portion has a first surface area. The block is anchorless and unsecured to the ground surface in the in-use location. The top portion has a second surface facing away from the ground surface and has a second surface area, which is substantially equal to the first surface area. The block remains substantially in the in-use location when a wheeled unit contacts the block.
[0013] Additional features, advantages, and embodiments of the invention may be set forth or apparent from consideration of the following detailed description, drawings, and claims. Moreover, it is to be understood that both the foregoing summary of the invention and the following detailed description are exemplary and intended to provide further explanation without limiting the scope of the invention as claimed.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] The accompanying drawings, which are included to provide further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate preferred embodiments of the invention, and, together with the detailed description below, serve to explain the principles of the invention. In the drawings:
[0015] [0015]FIG. 1 shows a perspective view of a pinless wheel bumper block in accordance with the principles of the invention.
[0016] [0016]FIG. 2 shows a side elevation view of the pinless wheel bumper block of FIG. 1.
[0017] [0017]FIG. 3 shows a top plan view of the pinless wheel bumper block of FIG. 1.
[0018] [0018]FIG. 4 shows another side elevation view of the pinless wheel bumper block of FIG. 1.
[0019] [0019]FIG. 5 shows a bottom plan view of the pinless wheel bumper block of FIG. 1.
[0020] [0020]FIG. 6 shows an expanded view of an edge of the pinless wheel bumper block of FIG. 1.
[0021] [0021]FIG. 7 shows an expanded end view of one of the forklift pockets of the pinless wheel bumper block of FIG. 1.
[0022] [0022]FIG. 8 shows a stack of several of the pinless wheel bumper blocks of FIG. 1.
[0023] [0023]FIG. 9 shows a perspective view of a forklift adapter coupled to an incompatible forklift for transporting the pinless wheel bumper blocks made in accordance with the invention.
[0024] [0024]FIG. 10 shows a side view of the forklift adapter of FIG. 9 coupled to an incompatible forklift and also showing a portion of the non-compatible forklift; and where four blocks of FIG. 1 are disposed on the forklift adapter.
[0025] [0025]FIG. 11 shows a front view of the forklift adapter of FIG. 9 and several stacked blocks of FIG. 1.
[0026] [0026]FIG. 12 shows a plan view of a wheeled chassis parking space arrangement in accordance with the principles of the invention using pinless wheel bumper blocks of FIG. 1.
[0027] [0027]FIG. 13 shows a perspective view of an alternate embodiment of a pinless wheel bumper block made in accordance with the principles of the invention.
[0028] [0028]FIG. 14 shows a perspective view of an alternate embodiment of a forklift adapter made in accordance with the principles of the invention.
[0029] [0029]FIG. 15 shows another alternate embodiment of a pinless wheel bumper block made in accordance with the principles of the invention.
[0030] [0030]FIG. 15A shows a side elevation view of a stack of pinless wheel bumper blocks made in accordance with the principles of the invention.
[0031] [0031]FIG. 16 shows a side elevation view of the pinless wheel bumper block of FIG. 15 taken along a line A-A.
[0032] [0032]FIG. 17 shows a side elevation view of a related art pinned wheel bumper block.
[0033] [0033]FIG. 18 shows a top plan view of the related art pinned wheel bumper block of FIG. 17.
[0034] [0034]FIG. 19 shows another side view of the related art pinned wheel bumper block of FIG. 17.
[0035] [0035]FIG. 20 shows a plan view of a wheeled chassis parking space arrangement using related art pinned wheel bumper blocks.
[0036] [0036]FIG. 21 shows a plan view of another wheeled chassis parking space arrangement using related art pinned wheel bumper blocks.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0037] Reference will now be made in detail to preferred embodiments of the invention, examples of which are illustrated in the accompanying drawings.
[0038] Referring to FIGS. 1 through 7, a preferred embodiment of a pinless wheel bumper block 100 is shown, for use in, for example, a marine container terminal or other type of space that has a need for wheel bumper blocks. In use, block 100 rests on a ground surface or underlying pavement without being secured or anchored, for example, by a pin, rod, or cementitious bond and, thus, can be referred to as a pinless wheel bumper block.
[0039] As illustrated best in the perspective view of FIG. 1, the block 100 has a three-dimensional, substantially flat, elongate, rectangular-like shape. The block 100 generally includes a top side 110 and a bottom side 120 with recesses 122 , 124 adapted to receive forklift blades and four sides 130 , 140 , 150 , 160 , two of which are shown in FIGS. 2 and 4.
[0040] Preferably, the pinless wheel bumper block 100 is a precast, reinforced concrete block. Alternatively, the block 100 can be formed in other ways, including from separate pieces. The block 100 can also be made of any suitable material of sufficient mass. Due to its mass and the forces of gravity and friction, the block 100 remains in place against the force that is reasonably expected to be applied to it by a wheeled container chassis without being anchored into the surface on which it rests. Alternatively, blocks 100 can be made of lighter materials with rough bottom surfaces to enhance the contact friction between the block 100 and the underlying pavement or ground surface without damaging the pavement or ground surface. For use in a wheeled marine container terminal environment, the block 100 preferably weighs approximately 5,250 pounds, and preferably is approximately fifteen feet long, four feet wide, and seven inches high. Thus, the length of the block 100 is substantially greater than the height of the block 100 . With these dimensions, the length being substantially greater than the height herein refers to a length-to-height ratio of approximately 25:1. The weight can vary depending upon the material used and the size of the block 100 . The dimensions can be modified in accordance with the invention.
[0041] The top 110 of block 100 has a top surface 111 that can be substantially parallel to a lower surface 121 . As shown for example in FIG. 2, the dimensions of the top surface 111 are about equal to the dimensions of the lower surface 121 . This provides for a relatively flat profile and low center of gravity, which provides stability to the block 100 during use as well as efficiency in stacking for purposes of block storage when not in use.
[0042] The four sides of the block 100 include a first end 130 , a second end 140 , a first side 150 , and a second side 160 that extend between top 110 and bottom 120 of block 100 . The first end 130 can be substantially parallel to the second end 140 . The first end 130 can be substantially perpendicular to both the first side 150 and the second side 160 . Likewise, the second end 140 can be substantially perpendicular to both the first side 150 and the second side 160 .
[0043] Certain edges of the block 100 can be beveled or chamfered to prevent chipping or spalling, including, for example, during handling, transport and stacking. As shown, in FIGS. 3 and 6, for example, each of the first and second ends 130 , 140 and the first and second sides 150 , 160 adjacent to the top 110 can include upper beveled portions, which are indicated as 132 , 142 , 152 , and 162 , respectively. Each of the first and second ends 130 , 140 and the first and second sides 150 , 160 adjacent the bottom 120 can include a chamfered portion, as shown, for example in FIGS. 2 and 6, which are indicated as 134 , 144 , 154 , and 164 , respectively.
[0044] The bottom 120 can include at least two recesses, shown as a first recess 122 and a second recess 124 . The recesses are positioned in the block 100 to receive a lifting device, such as a forklift adapter (as described below), the forks of a heavy-duty forklift, straps, chains, or other suitable devices to lift and transport the blocks 100 . The recesses 122 , 124 are symmetrical about the center of gravity of the block 100 . As the first and second recesses 122 , 124 are substantially alike, a detailed description of the second recess 124 will not be included. The first recess 122 extends into the block 100 from lower surface 121 and across the entire bottom 120 from the first side 150 to the second side 160 to form an elongate channel that is longer than it is wide. Although the extent of the first recess 122 can vary, especially, depending upon the type of lifting device used and can extend, for example, along only a portion of the bottom 120 , be smaller or larger, or form any other suitable shape. Varying the location and configuration of recesses 122 , 124 may affect the structural stability and durability of the block 100 .
[0045] As best illustrated in FIGS. 5 and 7, the first recess 122 includes a receiving face 123 , a left face 125 and a right face 127 . Preferably, left and right faces 125 , 127 are tapered with respect to the receiving face 123 . For example, the receiving face 123 forms a 45 degree angle with the left face 125 as well as the right face 127 . The receiving face 123 can form any suitable angle with the left face 125 and the right face 127 . This taper can assist in aligning the lifting device into the recesses 122 , 124 as well as prevent chipping or spalling of the block 100 .
[0046] The first recess 122 can be formed in the block 100 or can be machined from the block 100 . A centerline A of the first recess 122 is at a first distance from the first end 130 and the centerline B of the second recess 124 is at a second distance from the second end 140 . The first and second centerline distances are substantially the same.
[0047] [0047]FIG. 12 shows an example of one possible arrangement 300 of the blocks 100 . As shown, a parking stall 310 is defined by at least two stall markers 320 and one pinless wheel bumper block 100 . The stall marker 320 can be a marking on the pavement to guide a driver of a chassis. In the example shown, two rows 340 , 342 of parallel stall markers 320 are arranged with several pinless wheel bumper blocks 100 disposed between the two rows 340 , 342 of stall markers 320 . The shown configuration allows wheeled container chassis to be parked back-to-back without risk of backing a container chassis too far into the parking stall. The configuration of the blocks 100 can be rearranged easily when parking demand changes and without damage to the underlying pavement or to the block itself. Of course, other arrangements are possible, including arrangements useable in non-marine containerized freight terminals. Depending on the width of the parking stall, the block spacing and block length may vary and vehicles can be driven forward or backward into the parking stalls.
[0048] Referring now to FIG. 8, the blocks 100 can be readily stacked during periods of non-use or when rearranging an existing parking configuration. Properly stacked blocks 100 are stable and optimize space. As shown, several blocks 100 can be stacked one atop another. Preferably, a lower surface 121 of the bottom 120 of a first block 100 of a stack rests on the ground or pavement. Next, a lower surface 121 of the bottom 120 of a second block 100 is placed on the top surface 111 of the top 110 of the first block 100 . Such placement of the blocks 100 is repeated until a desired number of blocks is stacked. Other stacking configurations are possible. Alternatively, spacers (not shown) can be positioned between stacked blocks 100 as well as between the first block 100 of the stack and the ground or pavement. Spacers can allow an operator to use a forklift, which has a blade that otherwise would be too large to clear a distance between the receiving face 123 of the block 100 and the ground or the top surface 111 of a stacked block. Of course, varying the dimensions of the forklift recesses 122 , 124 determine dimensions of forklift blades that can be used.
[0049] [0049]FIG. 13 shows another embodiment of the invention in which pinless wheel bumper blocks 400 can interlock with other blocks 400 . The block 400 is similar to the first embodiment described above except that the block 400 has an interlocking feature. Thus, similar features will not be described in detail. The block 400 has a three-dimensional, substantially rectangular-like shape. The block 400 generally includes a top side 410 and a bottom side 420 with recesses 422 , 424 adapted to receive forklift blades and four sides 430 , 440 , 450 , 460 .
[0050] Preferably, the pinless wheel bumper block 400 is a precast, reinforced concrete block. Alternatively, the block 400 can be formed in other ways, including from separate pieces. The block 400 can also be made of any suitable material of sufficient mass. Due to its mass and the forces of gravity and friction, the block 400 remains in place against the force that is reasonably expected to be applied to it by a wheeled container chassis without being anchored into the surface on which it rests. For example, the block 400 can be made of wood, timber, solid plastics, or molded plastic shells filled with water, sand, stone, or the like. Alternatively, blocks 400 can be made of lighter materials with rough bottom surfaces to enhance the contact friction between the block 400 and the underlying pavement or ground surface without damaging the pavement or ground surface. Because of the interlocking structure, the block 400 can have a weight less than the weight of the block 100 . As discussed above, the weight can also vary depending upon the material used and the size of the block 400 . Other types of interlocking or interconnecting structures in accordance with the principles of the invention are possible.
[0051] The block 400 as shown includes a top 410 , a bottom 420 , a first end 430 , a second end 440 , a first side 450 , and a second side 460 . The top 410 has a top surface 411 that can be substantially parallel to a lower surface 421 . The first end 430 can be substantially perpendicular to both the first side 450 and the second side 460 . Likewise, the second end 440 can be substantially perpendicular to both the first side 450 and the second side 460 . The first end 430 includes a tongue 436 disposed in a middle portion of the first end 430 and preferably forms a substantially square-like projection from the first end 430 . The second end 440 includes a groove 446 that is adapted to receive the tongue 436 . Thus, arranging a series of blocks 400 with first end 430 next to second end 440 and engaging the tongue 436 and the groove 444 can form a length of interlocking blocks 400 .
[0052] Although the embodiments described above include recesses for being lifted by a forklift, the blocks in accordance with the invention do not require recesses for lifting and can be lifted using other devices where the block may not have corresponding structure. FIGS. 15 - 16 show another embodiment of the pinless wheel bumper block 600 , which is similar to the first embodiment described above, but the block 600 is not provided with recesses and is lifted using an alternate lifting device in an alternate manner (described below). Thus, like elements will not be described in detail. This alternate embodiment also has a three-dimensional, substantially rectangular-like shape.
[0053] Preferably, the block 600 is a precast, reinforced concrete block. Alternatively, the block 600 can be formed in other ways, including from separate pieces. The block 600 also can be made of any suitable material of sufficient mass. Due to its mass and the forces of gravity and friction, the block 600 remains in place against the force that is expected to be applied to it by a wheeled container without being anchored into the surface on which it rests. As discussed above, the weight can vary depending upon the material used, the size of the block 600 , and the surface friction between the block 600 and the ground or underlying pavement.
[0054] The block 600 includes a top 610 , a bottom 620 , a first end 630 , a second end 640 , a first side 650 , and a second side 660 . The first end 630 can be substantially perpendicular to both the first side 650 and the second side 660 . Likewise, the second end 640 can be substantially perpendicular to both the first side 650 and the second side 660 . The top 610 has a top surface 611 that can be substantially parallel to a lower surface 621 of the bottom 620 . The top 610 is not uniform, but includes at least one depression 612 formed therein. As shown in FIG. 15, block 600 includes two depressions 612 . Preferably, the depression 612 resembles a hemisphere, and in cross-section the cavity resembles a concave portion of a semicircle. Other configurations are possible. As best shown in FIG. 16, which is a cross-section taken along the line A-A in FIG. 15, embedded in the block 600 is a lifting device insert 613 . Lifting device insert 613 generally includes a top portion 616 and a bottom portion 615 interconnected by a post 617 . Preferably, a top surface 614 of the lifting device 613 is flush with the top surface 611 of the block 600 , which allows blocks 600 to be stacked atop each other. Alternatively, as shown in FIG. 15 a , a top surface 614 a of the lifting device 613 a extends beyond the top surface 611 of the block 600 . To stack blocks 600 atop each other, a pocket 622 , corresponding to the placement and size of the lifting device 613 , can be formed in the lower surface 621 of the bottom 620 of the block 600 .
[0055] As illustrated in FIG. 16, the bottom portion 615 of the lifting device 613 is preferably larger than the top portion 616 of the lifting device 613 to provide the lifting device 613 with sufficient engagement with the block 600 to prevent the lifting device 613 from being pulled-out of the block 600 when lifted. Bottom portion 615 can be in the shape of a post, disc, plate, eye, bend, bent rod, or any other configuration desired. The bottom portion 615 and a part of post 617 of the lifting device 613 are embedded in the block 600 beneath a cavity surface 612 a . The bottom portion 615 and part of post 617 of the lifting device 613 are set in the block 600 during casting of the block 600 . Alternatively, the lifting device 613 can be drilled or inserted into the block 600 after the block 600 has been cast. Preferably, the lifting device 613 is a lifting eye, i.e., an eyebolt or any hook-like or ring-like structure. The lifting device 613 can have alternate configurations in accordance with the invention, including, for example, a hook-like structure, a nail-head-like cross-section, or an I-beam-like cross-section. This block 600 is transported by coupling a strap, chain, harness, or the like to the top portion 616 of the lifting device 613 . The use of depressions 612 and lifting device insert 613 in block 600 may have greater overall structural strength and durability than blocks having forklift recesses as described above.
[0056] The blocks as described with reference to FIGS. 1 - 8 and 13 can be transported in a variety of ways, including, but not limited to the use of a compatible forklift or by using an incompatible forklift equipped with a forklift adapter 200 in accordance with the principles of the invention. As used herein, the term “compatible forklift” is used to denote a forklift that has properly sized blades to engage a particular load, for example the bumper block 100 . Blade sizing can refer to any or all of fork blade width, thickness, and length, as well as fork blade spread. Blade spread refers to the distance between the two forks. Generally, as used herein, the term “compatible forklift” refers to a forklift with a blade spread range that is capable of lifting and transporting a given load. The blade spread range can vary from the blades being adjacent one another to the blades extending a maximum distance opposite one another. As used herein, an “incompatible forklift” is one in which the blade spread is inadequate for safely lifting and transporting a given load, i.e., an out-of-gage load. In other words, lifting and transporting an out-of-gage load would require a greater or lesser blade spread range than the existing blade spread range of an incompatible forklift.
[0057] Referring now to FIGS. 9 - 11 , a forklift adapter 200 is shown coupled with blades F 1 ,F 2 (shown in phantom lines) of an incompatible forklift F (shown in phantom lines). Although shown with reference to wheel bumper blocks, the forklift adapter 200 is not limited to lifting and transporting wheel bumper blocks. The forklift adapter 200 can lift and transport a variety of other loads, such as lumber and pallets. Thus, the forklift adapter 200 has its own set of adapter blades 246 , 256 , adapted to lift and transport the blocks 100 using an incompatible forklift F that would not otherwise be capable of lifting the blocks 100 . The adapter 200 is preferably made of steel or can be made of any suitable material. The adapter 200 is preferably formed of separate parts, which are coupled by welding or other appropriate coupling means, but can be formed in other ways. As shown in FIG. 11, a forklift with a maximum blade spread D 1 is an incompatible forklift and is incapable of lifting and transporting the illustrated stack of blocks. The forklift adapter 200 has a maximum blade spread of D 2 , which is greater than D 1 . The blade spread D 2 is sufficient to lift and export the load depicted in FIG. 11, whereas the blade spread D 1 is not. Thus, the forklift adapter 200 can convert an incompatible forklift to a compatible forklift. Alternatively, the forklift adapter 200 can have a blade spread that is smaller than the blade spread of an incompatible forklift adapter.
[0058] The forklift adapter 200 as shown, generally resides below the blades F 1 ,F 2 of the incompatible forklift F (see, for example, FIG. 10). The forklift adapter 200 includes first and second mounting tubes 210 , 220 , a mounting bar 230 , and first and second block supports 240 , 250 . The first and second mounting tubes 210 , 220 are each adapted to accommodate blades F 1 ,F 2 of an incompatible forklift F. Thus, the first and second mounting tubes 210 , 220 are hollow in cross-section and tapered along their length. Alternatively, the mounting tubes 210 , 220 are not tapered. Whether or not the mounting tubes 210 , 220 are tapered depends on whether the forklift and blades are tapered.
[0059] The first and second mounting tubes 210 , 220 are connected by the mounting bar 230 that extends substantially perpendicular to the length of tubes 210 , 220 . A first end 232 of the mounting bar 230 is coupled to the first mounting tube 210 and a second end 234 of the mounting bar 230 is coupled to the second mounting tube 210 . The first and second ends 232 , 234 of the mounting bar 230 are disposed on opposite ends of the mounting bar 230 . The mounting bar 230 can be solid or hollow in cross-section.
[0060] As the first and second block supports 240 , 250 are virtually the same, only the first block support 240 will be described in detail. The first block support 240 includes a mounting bar attachment 242 , a vertical member 244 , and the adapter blade 246 . The first block support 240 can be a unitary whole or can be manufactured of separate components. The mounting bar attachment 242 can be substantially similar in cross-section and material as the mounting bar 230 . Additionally, the mounting bar attachment 242 can be substantially axially aligned with the mounting bar 230 . The vertical member 244 is coupled to and extends away from the mounting bar attachment 242 and is substantially perpendicular to the first mounting tube 210 . The vertical member 244 can preferably include a rubber pad on a face that contacts the blocks 100 to prevent damage to the blocks 100 during transport. To provide additional structural support to first block support 240 , stiffening members can be used as shown. Other arrangements of structural supports can be used as well. A first stiffening member 247 connects the vertical member 244 to the mounting bar 230 , and a first support 248 connects the vertical member to the first mounting tube 210 . The adapter blade 246 extends perpendicularly from the vertical member 244 . The vertical member 244 and the adapter blade 246 generally form an L-shape. The adapter blade 246 is substantially parallel to the first mounting tube 210 . The adapter blade 246 is adapted to engage the first and second recesses 122 , 124 of the block 100 . Likewise, first and second block supports 240 , 250 are spaced apart from each other by a distance so as to correspond to the distance between recesses 122 , 124 in block 100 . The adapter 200 is preferably free-standing when not in use, which facilitates the mounting and dismounting of the adapter 200 with non-compatible forklifts. Alternatively, where the adapter 200 is not free-standing, supports (not shown) may be added to the adapter 200 or may be external to the adapter 200 to facilitate the mounting/dismounting of the adapter 200 with non-compatible forklifts.
[0061] In operation, a forklift operator guides the forklift blades F 1 ,F 2 through the first and second mounting tubes 210 , 220 of the adapter 200 . Once the adapter 200 is securely in position on the forklift, the operator can direct the adapter 200 to a block 100 or a stack of blocks 100 as shown in FIGS. 10 and 11. Although not shown, devices such as bolts, pins, stay-chains, brackets, straps, braces, friction fits, wedges, or other securing means can be used to secure the adapter 200 to the non-compatible forklift F. To place the blocks 100 on the adapter 200 , the forklift operator engages the first and second recesses 122 , 124 with the adapter blades 246 , 256 of the first and second block supports 240 , 250 of the forklift adapter 200 . Once the blocks 100 are firmly on the adapter 200 , as illustrated in FIGS. 10 and 11, the forklift operator can lift and transport the blocks 100 to a desired location for placement.
[0062] [0062]FIG. 14 shows another embodiment of a forklift adapter 500 according to the principles of the invention. The forklift adapter 500 generally resides below the blades F 1 ,F 2 of the non-compatible forklift. The forklift adapter 500 includes first and second side sections 510 , 520 , front and rear lateral supports 530 , 540 , and first and second fork assemblies 550 , 560 .
[0063] Preferably, the first and second side sections 510 , 520 are substantially parallel. Each of the first and second side sections 510 , 520 have two hollow, square cross-sections coupled together. The first side section 510 includes an outer side 510 a and an inner side section 510 b . The outer and inner side sections 510 a , 510 b are adjacent and coplanar. The inner side section 510 b is hollow and adapted to receive a blade F 1 of an incompatible forklift (not shown). The front and rear lateral supports 530 , 540 are each formed of two adjoining hollow, square cross-sections coupled together and are substantially parallel to one another. Alternatively, each of the front and rear lateral supports 530 , 540 can be formed of a unitary whole, of a different cross-section, or solid. The front and rear lateral supports 530 , 540 are substantially perpendicular to the first and second side sections 510 , 520 . The front and rear lateral supports 530 , 540 extend between and are coupled to portions of the first and second side sections 510 , 520 . The first and second side sections 510 , 520 and the front and rear lateral supports 530 , 540 form a generally rectangular shape. Coupled to an underside 512 of the outer side section 510 a of the first side section 510 is the first fork assembly 550 . The outer and inner side sections 520 a , 520 b of the second side section 520 are adjacent and coplanar. The inner side section 520 b of the second side section 520 is hollow and adapted to receive another blade F 2 of the incompatible forklift (not shown). Coupled to an underside 522 of the outer side section 520 a of the second side section 520 is the second fork assembly 560 . A stiffening bar 553 couples the first and second forklift assemblies 550 , 560 . The stiffening bar 553 can be coupled to the first and second forklift assemblies 550 , 560 by welding or other suitable means. The stiffening bar 553 is preferably made of steel, has a square cross-section and is hollow. The stiffening bar can be made of any other suitable material and cross-section and can be solid. As the first and second forklift assemblies 550 , 560 are virtually the same, only the first forklift assembly 550 will be described in detail herein.
[0064] The first forklift assembly 550 includes a first vertical member 552 , a first horizontal member 554 , a first strut 556 , and a first support 558 . The first forklift assembly 550 can be formed of separate components and coupled together by, for example, welding. Alternatively, the forklift assembly 550 can be formed as a unitary whole.
[0065] The first vertical member 552 is coupled to and depends from the underside 512 of the outer side section 510 a of the first side section 510 . Coupled to the first vertical member 552 is the first horizontal member 554 . The first horizontal member 554 is adapted to engage the first and second recesses 122 , 124 of the block 100 . The first horizontal member 554 is substantially perpendicular to the first vertical member 552 . The first vertical and horizontal members 552 , 554 generally form an L-shape. The first strut 556 couples the first vertical member 552 to the underside 512 . The underside 512 , the first vertical member 552 , and the first strut 556 form a generally triangular shape. Also coupled to the first vertical member is the stiffening bar 553 . The first support 558 is coupled to and substantially perpendicular to the first strut 556 . When not in use, the forklift adapter 500 rests on the ground or pavement with the first support 558 and the first horizontal member 554 in contact with the ground or pavement.
[0066] The use and operation of the forklift adapter 500 is substantially similar to that described above for the forklift adapter 200 . Thus, similarities will not be repeated herein. To secure the forklift adapter 500 to the non-compatible forklift F, the forklift operator positions the forklift F near the forklift adapter 500 . To engage the forklift F with the forklift adapter 500 , the forklift operator extends the forklift blades F 1 ,F 2 and penetrates the inner side 510 b of the first side section 510 and the inner side 520 b of the second side section 520 so as to secure the forklift (not shown) to the forklift adapter 500 . Although not shown, the forklift adapter 500 can be further secured to the forklift F by bolts, pins, stay-chains, brackets, straps, braces, friction fits, wedges or other securing means. Thus, the forklift adapter 500 can convert an incompatible forklift to a compatible forklift.
[0067] Although the foregoing description is directed to the preferred embodiments of the invention, it is noted that other variations and modifications will be apparent to those skilled in the art, and may be made without departing from the spirit or scope of the invention. Moreover, features described in connection with one embodiment of the invention may be used in conjunction with other embodiments, even if not explicitly stated above. | An anchorless wheel bumper block is used as a stop in a parking facility. The block includes a base with a bottom surface, a top with an upper surface, and a side extending around a perimeter of the block and between the bottom and upper surfaces. The bottom surface rests on a ground surface and the block is in contact with and unattached to the ground surface in an in-use position. The bottom surface is disposed in a first plane and has a length. The upper surface is disposed in a second plane generally parallel to the first plane. A distance between the bottom and upper surfaces defines a height of the block. The length is substantially greater than the height of the block. The block remains substantially in the in-use position when a wheeled unit contacts the block. | 1 |
CROSS-REFERENCE
[0001] This application is a continuation of U.S. patent application Ser. No. 10/186,399, filed Jul. 1, 2002, now abandoned, which is a continuation of U.S. patent application Ser. No. 09/538,445, filed Mar. 29, 2000, now abandoned, which is a continuation of U.S. patent application Ser. No. 09/104,863, filed Jun. 25, 1998, now abandoned, which is a continuation in part of U.S. patent application Ser. No. 08/320,432, filed Oct. 7, 1994 entitled “Cytoplasmic Tyrosine Kinase,” which is hereby incorporated by reference in its entirety.
BACKGROUND OF THE INVENTION
[0002] The field of the invention is control of vascular endothelium. The vascular endothelium controls important properties, such as inflammatory responses, the regulation of a nonthrombogenic surface and responses of the vessel wall to products of platelet activation on the vessel wall, and recanalization of vascular occlusions by thrombi. Arteriosclerosis is considered to arise in part because of failure of the nonthrombogenic vessel surface, and preferred sites for arteriosclerosis are arterial bifurcations and sites of high shear pressure and turbulent blood flow. At such sites, microaggregates of platelets are thought to form and be activated, resulting in the release of substances that promote arteriosclerosis. Clotted blood or fibrin deposits often form in damaged vessel walls at such sites. Thrombin is a proteolytic enzyme of the blood clotting cascade, which has unique effects on the formation and deposition of fibrin clots and on the properties of the vascular endothelium of the vessel wall. Thrombin is highly stimulatory for endothelial cell growth (mitosis) and migration in culture and it causes cytoskeletal changes in the stimulated cells (Van Obberghen-Schilling et al. (1995) Annals of the New York Academy of Sciences 766:431-41).
[0003] Platelets play an essential role in acute coronary syndromes such as unstable angina and myocardial infarction (Handin (1996) New England Journal of Medicine 334(17):1126-7). In addition, platelet inhibitory trials suggest that activation of platelets plays an important role in the natural history of coronary artery disease in general as well as in coronary bypass graft disease (Le Breton et al. (1996) Journal of the American College of Cardiology 28(7): 1643-51). Although under normal conditions platelets circulate in the blood an inactivated state, under pathological conditions, the cells can be stimulated to release a variety of substances such as serotonin and thromboxane A2, which evoke potent vasoconstriction and further activation of platelets. In patients with coronary artery disease, local platelet activation commonly occurs and contributes to local vasospasm, thrombus formation, and eventually vascular occlusion. Thrombin is a potent platelet activator and has been implicated in thrombotic coronary artery occlusion and in particular in vascular reocclusion after coronary thrombolysis and angioplasty. Antithrombin therapy appears to prevent vascular reocclusion after thrombolysis in an animal model (Gallo et al. (1998) Circulation 97(6):581-8).
[0004] In addition to platelets, thrombin activates endothelial cells of human arteries (Garcia et al. (1995) Blood Coagulation & Fibrinolysis 6(7):609-26). Endothelial cells manifest antithrombotic activity by releasing vasoactive substances with antiplatelet activities such as the endothelium-derived nitric oxide and prostacyclin. Platelet-derived substances (i.e., adenine nucleotides, serotonin) and thrombin, on the other hand, cause endothelium-dependent relaxation, at least in certain blood vessels. Hence, platelet-derived substances such as serotonin, ADP, and ATP as well as thrombin can activate platelets and stimulate the release of nitric oxide and prostacyclin from the endothelium. Thus, depending on the functional status of the endothelium, the thrombin-regulated substances should differentially affect the vessel wall. Since endothelial dysfunction, and in particular a decreased release of nitric oxide and prostacyclin, occurs in coronary artery disease, these mechanisms may have important implications in unstable angina and myocardial infarction (Yang et al. (1994) Circulation 89(5):2266-2272; herein incorporated by reference).
[0005] The vascular endothelium of arteries is subject to physiological stresses, such as high intravascular pulsatile pressure and shear stress, which have been shown to control gene expression in endothelial cells (Gimbrone et al. (1997) Journal of Clinical Investigation 100(11 Suppl):S61-5; herein incorporated by reference). Such influences on the endothelial cells, including readjustment of gene expression to stressful conditions, are controlled by signals from the extracellular fluid and pericellular matrix via specific cell surface receptors, such as hemopoietin-cytokine receptors, receptor tyrosine kinases and G-protein coupled receptors ( Guidebook to Cytokines and Their Receptors, Nicos A. Nicola (Ed.), Oxford University Press, 1994; herein incorporated by reference). For example, shear stress has been shown to lead to changes in the TGFβ-SMAD signal transduction in endothelial cells, which is considered, among other things, to lead to changes in the biosynthesis of extracellular matrix components by the cells (Topper et al. (1997) Proceedings of the National Academy of Sciences of the United States of America 94(17):9314-9).
[0006] Recent evidence shows that there are endothelial cell specific growth factors and receptors that may be primarily responsible for the stimulation of endothelial cell growth, differentiation and certain differentiated functions. The best studied of these is vascular endothelial growth factor (VEGF). VEGF is a dimeric glycoprotein of disulfide-linked 23 kD subunits. Other reported effects of VEGF include the mobilization of intracellular calcium, the induction of plasminogen activator and plasminogen activator inhibitor-1 synthesis, stimulation of nitric oxide release and hexose transport in endothelial cells, and promotion of monocyte migration in vitro. VEGF was originally purified from several sources on the basis of its mitogenic activity toward endothelial cells, and also by its ability to induce microvascular permeability, hence it is also called vascular permeability factor (VPF).
[0007] Two high affinity receptors for VEGF have been characterized: VEGFR-1/Flt-1 (fms-like tyrosine kinase-1) and VEGFR-2/KDR/Flk-1 (kinase insert domain containing receptor/fetal liver kinase-1). Those receptors have seven immunoglobulin-like loops in their extracellular domain, and they possess a longer kinase insert than normally observed in other receptors of this family. The expression of VEGF receptors occurs mainly in vascular endothelial cells, although some may be present on hematopoietic progenitor cells, monocytes, osteoblasts, corneal endothelial cells, pericytes, leydig and sertoli cells and melanoma cells. Only endothelial cells have been reported to proliferate in response to VEGF, and endothelial cells from different vessels show different responses (see e.g., review by Korpelainen and Alitalo (1998) Current Opinion in Cell Biology 10:159-164; Jeltsch et al. (1997) Science 276:1423-1425; herein incorporated by reference). Thus, the signals mediated through VEGF receptors appear to be cell type specific. The VEGF-related placenta growth factor (PlGF) was recently shown to bind to VEGFR-1 with high affinity. PlGF was able to enhance the mitogenic or growth factor activity of VEGF, and stimulated DNA synthesis in capillary endothelial cells (Ziche et al. (1997) Laboratory Investigation 76(4):517-31; herein incorporated by reference). Naturally occurring VEGF/PlGF heterodimers were nearly as potent mitogens as VEGF homodimers for endothelial cells (Cao et al., (1996) J. Biol. Chem., 271:3154-62; herein incorporated by reference).
[0008] Cytokines may also activate important signals for the reprogrammming of vascular endothelial cells. For example, IL-3 is a haemopoietic growth factor which stimulates the production and functional activity of various blood cell types. Recent evidence suggests that the target cell population of IL-3 is not restricted to haemopoietic cells as previously thought, but vascular cells such as endothelial cells also express receptors for and respond to this cytokine. IL-3 was found to regulate endothelial responses related to inflammation, immunity and haemopoiesis (Korpelainen et al. (1996) Immunology & Cell Biology 74(1):1-7; herein incorporated by reference). Immune mechanisms also play a major role in the development of arteriosclerosis (Yokota and Hansson (1995) J. Internal Medicine 238(6):479-89). Thus the function of IL-3 may be of clinical importance, as IL-3 can be used in bone marrow reconstitution following cancer therapy.
[0009] Another example is thrombin, which is activated by blood clotting, has strong effects on endothelial cells directly, via an endothelial G-protein coupled thrombin receptor, and via platelet activation with the resulting release of effectors from platelet alpha granules.
[0010] Certain of such signals, such as those via the cytokine, receptor tyrosine kinase and G-protein coupled receptors, may be transmitted via cytoplasmic tyrosine kinases. Tyrosine protein kinases (TKs) are essential components of signal transduction in endothelial cells. Several of the TKs function as transmembrane receptors, transducing signals from growth factors to the cytoplasm (Mustonen and Alitalo (1995) J. Cell Biol. 129: 895-898; herein incorporated by reference). The extracellular domains of the receptor TKs are responsible for ligand binding, while the intracellular TK domains transmit the activation signals through phosphorylation of cellular polypeptides. Five different endothelial cell receptor TKs are known, encoded by two different gene families (Mustonen and Alitalo, supra). Before our studies on Bmx, non-receptor tyrosine kinases relatively specific for endothelial cells had not been reported.
[0011] The Bmx TK belongs to the so-called Btk subfamily (Vihinen and Smith. (1996) Crit. Rev. Immunol. 16(3):251-275 ). The four proteins encoded by members of this gene family share substantial homology, including typical SH2 and SH3 domains upstream of the TK domain. A special feature of these TKs is a so-called pleckstrin homology (PH) domain in the N-terminal region (Musacchio et al. (1993) TIBS 18:343-348). Several of these non receptor TKs have been shown to be expressed in various cultured hematopoietic cell lines. The Tec TK is expressed in all murine hematopoietic cell lines examined (Mano et al. (1990) Oncogene 5:1781-1786). The Tec kinase is activated by multiple cytokine receptors in the hematopoietic cells and by thrombin and integrin signals in blood platelets (Hamazaki et al. (1998) Oncogene 16:2773-2779). Itk (Gibson et al. (1993) Blood 82:1561-1572) and Btk (de Weers et al. (1993) Eur J Immunol. 23:3109-3114) are selectively expressed at certain stages of lymphocyte development and the expression of the Txk TK has been assigned to T-cells (Sommers et al. (1995) Oncogene 11:245-251).
[0012] The Bmx TK gene was isolated while screening for novel TK genes expressed in human bone marrow (Tamagnone et al. (1994) Oncogene 9:3683-3688; herein incorporated by reference). Because the gene was mapped to chromosome X at Xp22.2, it was called Bmx, Bone Marrow tyrosine kinase gene in chromosome X. The X chromosome is the location of at least one known tyrosine kinase gene-linked disease in humans, the X-linked agammaglobulinemia. Several other human mutations are known in genes located in the X-chromosome, which lead to disease in a hemizygous position in males, because of the lack of another X-chromosome and thus in many cases the lack of a healthy allele in male cells. In comparison with other Btk family members, Bmx lacks the so-called P—X—P motifs but has extra peptides in between PH and SH3 and SH2 domains. The SH3 sequence does not conform precisely to the described consensus.
SUMMARY OF THE INVENTION
[0013] The invention can be used to treat or prevent arteriostenosis, or narrowing of the lumen of an artery or the heart, e.g., by arteriosclerosis (hardening of the wall of an artery), in a patient by regulating the activity of Bmx tyrosine kinase in arterial endothelial cells and/or endocardial endothelial cells in a manner sufficient to inhibit inflammatory responses, growth signals, or to reduce thrombogenic tendencies or properties of such endothelia. The inhibition of Bmx in the endothelium will inhibit the intimal migration and growth of associated smooth muscle cells from the tunica media of arteries.
[0014] In preferred embodiments, the arteriostenosis to be treated arises from arteriosclerosis or vasospasm; and preferably the Bmx tyrosine kinase regulation occurs by administering to the patient to be treated an agent capable of inhibiting Bmx tyrosine kinase activity. By “patient” is meant an animal, preferably a mammal, more preferably a human. By “agent” is meant a ligand, drug, chemical, compound, nucleic acid, or any other substance which, directly or indirectly, is capable of acting on the desired target. For example, if Bmx tyrosine kinase activity involves the tyrosine phosphorylation of another protein, an effective agent would be one administered to the patient which prevents Bmx from phosphorylating another protein due to interference with any link in the upstream cascade of molecular events within a cell which leads to such phosphorylation, or impedes the phosphorylation directly.
[0015] In preferred embodiments, a tyrosine kinase inhibitor or BMX antisense cDNA is the agent used to inhibit the Bmx tyrosine kinase activity. Alternatively, genetically modified BMX cDNA is used to express altered Bmx protein; this Bmx or the BMX cDNA is molecularly or functionally distinguishable from naturally occurring BMX DNA or Bmx protein. By “molecularly or functionally distinguishable” is meant that one of skill in the art using art-known techniques (e.g., nucleic acid or amino acid sequencing, or in vitro phosphorylation assays) could determine that the Bmx is not of natural origin or is not the exact molecule normally found in nature in the animal in question.
[0016] Preferably, the region of endocardial or arterial endothelium or smooth muscle targeted is an area of turbulent vascular flow, such as, e.g., the chambers of the heart, areas of vessel bifurcation, or diseased regions (e.g., those with developing atherosclerotic plaques). The agent can be directly (e.g., via a catheter) or indirectly (e.g., via agents introduced into the body or circulation alone, in liposomes, vectors, etc.) administered to the vascular endothelium or endocardium of the patient.
[0017] In other preferred embodiments, the regulation of Bmx tyrosine kinase activity is via a ligand which is able to bind to a cell surface receptor (e.g., on an endothelial cell) which, when bound, elicits a molecular (e.g., phosphorylation) cascade linked to Bmx tyrosine kinase. By “ligand” is meant an extracellular molecule which specifically binds to a receptor (e.g., a vascular endothelial growth factor receptor such as VEGFR-1/Flt-1 or VEGFR-2/KDR/Flk-1) and either blocks or elicits an intracellular cascade, leading to increased or decreased activity of the target molecule. Particularly preferred ligands of the invention are interleukin-3 (IL-3) and vascular endothelial growth factor (VEGF).
[0018] Particularly preferred embodiments include regulating Bmx tyrosine kinase activity in endocardial and/or arterial endothelial cells and/or arterial smooth muscle cells in order to inhibit, reduce, or prevent a thrombotic (clotting), mitotic (cell division) or inflammatory (e.g., cytokine mediated) effects in such cells or surrounding smooth muscle cells. Inhibiting the effects of the compounds thrombin, IL-3, and VEGF is particularly preferred.
[0019] In another embodiment, regulation of Bmx is in order to accelerate the re-endothelialization of damage endothelium after surgery in the vessel wall, such as balloon angioplasty or the implantation of a vascular prosthesis. By “re-endothelialization is meant the regrowth of healthy endothelial lining of a vessel damaged by disease or trauma (e.g., surgical procedure.) Yet another application is for the relaxation of arterial smooth muscle cells adjacent to the endothelial cells, via regulation of endothelial cell Bmx kinase activity.
[0020] A preferred embodiment of the invention is a method of identifying agents which affect a Bmx tyrosine kinase signaling pathway, the method comprising applying an agent or agents to be tested to the tissue of a transgenic animal or to such an animal itself, the cells of the animal having a genetic defect in the Bmx encoding region of the genome, the defect causing an abnormal Bmx signaling pathway (e.g., because of a defective protein or a defect in expression of the protein), and a suitable agent being one which functionally restores at least one step in the abnormal pathway. By “step in the pathway” is meant DNA transcription, RNA translation, or protein function, e.g., proper cleavage or conformation/folding, enzymatic properties (phosphorylation), or ability to participate in a molecular cascade (e.g., to be phosphorylated).
[0021] Another preferred embodiment is a method for diagnosing a human defect or disease associated with Bmx dysfunction (e.g., protein dysfunction or transcriptional/translational dysfunction of the nucleic acids) caused by a mutation in the BMX gene on chromosome X of a patient, the method comprising an assay of the BMX gene and an analysis of the assay results sufficient to detect the mutation. Any assays known in the art for detecting mutations or gene defects or abnormalities may be used, such as restriction digests, PCR assays, nucleic acid sequencing, Southern or Northern blotting, hybridization of labeled oligonucleotides to the gene, or any suitable commercial kits (e.g., technology such as Incstar's Gen-eti-k DEIA kit for enzyme immunoassay detection of double stranded DNA (detecting hybridized probe and template DNA)).
[0022] Terms used herein are to be given their art-known meaning. For example, the term “antisense” means an RNA or DNA sequence which is sufficiently complementary to a particular target RNA or DNA molecule for which the antisense RNA or DNA is directed to cause molecular hybridization between the antisense RNA or DNA and the target RNA or DNA such that transcription or translation of RNA or protein is inhibited. Such hybridization occurs in vivo, that is, inside the cell. The action of the antisense molecule results in specific inhibition of gene expression in the cell. (See: Alberts, B. et al., Molecular Biology of the Cell, 2nd Ed., Garland Publishing, Inc., New York, N.Y. (1989), in particular, pages 195-196; herein incorporated by reference.) The antisense molecule may be comprised of 10 or more naturally or non-naturally occurring nucleotides (e.g., an example of a non-naturally occurring nucleotide could include molecules with enhanced hybridization affinity such as described in U.S. Pat. No. 5,432,272, herein incorporated by reference). “Arteriostenosis” means a narrowing, hardening, or occlusion of the caliber of an artery, either temporarily, through e.g., vasoconstriction, or permanently, through e.g., arteriosclerosis. (See, e.g., Stedmans Medical Dictionary, 25th Ed., Williams & Wilkins, Baltimore, Md., (1990)).
DESCRIPTION OF THE DRAWINGS
[0023] FIG. 1A : The mouse Bmx cDNA structure and the isolated clones are shown schematically;
[0024] FIG. 1B : A comparison of the deduced amino acid sequences of mouse (SEQ ID NO: 2) and human (SEQ ID NO: 3) Bmx genes is shown;
[0025] FIG. 1C : mRNA signals obtained from the heart and lung;
[0026] FIG. 2 : In 10.5 ( FIG. 2A ) and 12.5 ( FIG. 2B ) day p.c. mouse embryos the Bmx autoradiographic signals decorated the heart endocardium;
[0027] FIG. 3 : Transverse sections of the thoracic cavity show strong Bmx mRNA signals present in the aortal endothelial cells and subclavian arteries as well as in the intervertebral arteries ( FIGS. 3A and B). Signal was seen also in the umbilical arteries ( FIGS. 3C and 3D ). Such signals were considerably weaker in the aortic endothelium of 16.5 day mouse embryos ( FIGS. 3E and 3F ). The Bmx sense probe did not give a signal in any of these sections ( FIGS. 3G and 3H ). Autoradiographic signals were obtained from the heart endocardium of the left ventricle and from aorta ( FIGS. 3J and 3K ). The coronary arteries showed a weak but definitive hybridization signal (FIGS. 3 L and 3 M);
[0028] FIG. 4 : Co-expression of Jak1and Jak2 induces phosphorylation of kinase dead Bmx;
[0029] FIG. 5 : Comparison of Bmx phosphorylation level after cotransfection with Epo, GCSF, Flt1, KDR or Flt4 receptors;
[0030] FIG. 6 : Flt1, GCSF and Epo receptors increase Bmx in vitro kinase activity;
[0031] FIG. 6A : 293T cells were transfected with Bmx together with indicated receptors. Bmx was immunoprecipitated from cell lysates using anti-HA-Ab and kinase activity was measured as described in materials and methods;
[0032] FIG. 6B : Kinase reactants were electrophoresed in 7.5% SDS-PAGE. The gel was dried and Bmx autokinase activity was visualised by exposure on film;
[0033] FIG. 6C : A part of the same immunoprecipitants were electrophoresed in 7.5% SDS-PAGE, transferred to nitrocellulose membrane and immunoblotted with anti-Bmx-Ab;
[0034] FIG. 7 : Flt1 stimulates Bmx kinase activity, but other VEGF receptors do not;
[0035] FIG. 7A : 293T cells were transfected with Bmx together with indicated receptors; Bmx was immunoprecipitated from cell lysates using anti-HA-Ab and kinase activity was measured as described in materials and methods;
[0036] FIG. 7B : Kinase reactants were electrophoresed in 7.5% SDS-PAGE. The gel was dried and Bmx autokinase activity was visualised by exposure on film;
[0037] FIG. 7C : A part of the same immunoprecipitants were electrophoresed in 7.5% SDS-PAGE, transferred to nitrocellulose membrane and immunoblotted with anti-Bmx-Ab;
[0038] FIG. 8 : Endogenous receptors for interleukin 3 and GCSF increase Bmx kinase activity. 32Dcl3 cells expressing Bmx or kinase dead Bmx were starved overnight in IL-3 free media and then stimulated with IL-3 or GCSF. Bmx was immunoprecipitated from cell lysates using anti-HA-Ab and kinase activity was measured;
[0039] FIG. 9 : Activation of endogenous Bmx of endothelial cells;
[0040] FIG. 9A : Human Umbilical Vein Endothelial Cells (HUVECs) were starved overnight and then stimulated with indicated factors with or without inhibitors of PI-3 kinase. Bmx was immunoprecipitated from cell lysates using anti-HA-Ab and kinase activity was measured;
[0041] FIG. 9B : Kinase reactants were electrophoresed in 7.5% SDS-PAGE. The gel was dried and Bmx autokinase activity was visualised by exposure on film;
[0042] FIG. 9C : Shown in panel C is an immunoblot from total cell lysates electrophoresed in 6% SDS-PAGE blotted with endothelial specific anti-CD31 Ab;
[0043] FIG. 10 : Knock-in type gene targeting of mouse Bmx in embryonic stem cells.
[0044] FIG. 10A : Schematic representation of the targeting construct and the wild-type and targeted mouse Bmx locus. Using this strategy, the first coding exon has been replaced by the LacZ and neomycin casettes by homolougus recombination. E=Eco RI, B=Bam HI, H=Hind III, S=Sac I X=Xho I, C=Cla I, EV=Eco RV restriction endonuclease cleavage sites. WT=wild-type, TV=targeting vector, TL=Targeted locus. Arorwheads with LoxP indicate the sequence Cre mediated recombination.
[0045] FIG. 10B : A Southern blot showing Bmx gene analysis in ES cell clones after electroporation and drug selection. The wild-type and gene-targeted DNA hybridization signals are indicated in the figure. WT indicates the migration of the wild type fragment, Targeted indicates the gene targeted DNA fragment.
DETAILED DESCRIPTION
[0046] The growth and differentiation of endothelial cells is regulated by signal transduction through tyrosine protein kinases. We have discovered that the novel cytoplasmic tyrosine kinase gene, Bmx (Bone Marrow tyrosine kinase gene in chromosome X ), originally identified in human bone marrow RNA and found to be expressed predominantly in hematopoietic progenitor and myeloid hematopoietic cell lineages, is also highly expressed in human heart endocardium and, importantly, in the endothelium of large arteries. This TK shows unique specificity of expression among tyrosine kinase genes and is involved in signal transduction in endocardial and arterial endothelial cells (Ekman et al. (1997) Circulation 96(6):1729-1732, the disclosure of which is herein incorporated by reference).
[0047] Vascular endothelial physiology and pathology, such as arteriosclerosis is largely determined by a receptor-mediated regulation of endothelial cell functions, with associated pathology of the adjacent smooth muscle cell layer. Regulation of Bmx has effects on vascular endothelial cells through Bmx's effect on signal transduction via endothelial cell receptors.
[0048] Regulation of vascular endothelial function and inhibition of the development of arteriostenosis such as arteriosclerosis according to the instant invention can be achieved by regulating endogenous Bmx expression in endothelial cells via the Bmx signaling pathway and/or promotor. Alternatively, Bmx expression can be enhanced by stably or transiently incorporating Bmx DNA or RNA into arterial endothelial cells or decreased by transfecting antisense DNA into endothelial cells. The best way, however, to regulate Bmx function is by use of specific tyrosine kinase inhibitors, such as those described for the PDGF and VEGF receptors (Strawn et al. (1996) Cancer Research 56(15):3540-5; Kovalenko et al. (1997) Biochemistry 36(21):6260-9).
[0049] In addition to tyrosine kinase inhibitors, small molecular weight inhibitors of signal transduction, such as Wortmannin, which inhibits phosphoinositide 3-kinase can be used to inhibit hemopoietin-cytokine receptor, receptor tyrosine kinase and G-protein coupled receptor signaling (Levitzki (1997) Medical Oncology 14(2):83-9). Such compounds and others can be useful in inhibiting the coupling of receptors to cytoplasmic tyrosine kinases either directly or via docking proteins or intermediate enzymes, which catalyze steps important for the transduced signals. Furthermore, the elucidation and structural analysis of the protein-protein interactions of tyrosine kinases using e.g. the yeast two-hybrid system and crystal structure determination of the isolated domains such as Bmx will make it possible to devise additional pharmacological inhibitors.
[0050] Endothelial cells can be modified (e.g., by transfection) to express incorporated genetic material such as naturally occurring or non-naturally occurring/modified BMX genes to produce the encoded product at levels sufficient to produce the normal physiological effects of the Bmx protein if that is desired, or to inhibit (e.g., through antisense) endogenous production of Bmx. The incorporated genetic material may encode a selectable marker, thus providing a means by which cells expressing the incorporated genetic material are identified. Endothelial cells containing incorporated genetic material are referred to as transduced endothelial cells.
[0051] Any method or vector suitable for transfection of endothelial cells can be used, e.g., as in Mulligan et al., U.S. Pat. No. 5,674,722, herein incorporated by reference. For example, viral or retroviral vectors have been used to stably transduce endothelial cells with genetic material which includes genetic material encoding a polypeptide or protein of interest not normally expressed at biologically significant levels in endothelial cells. Using, e.g., a retroviral vector, the Bmx mRNA or antisense can be controlled by a retroviral promoter. Alternatively, retroviral vectors having additional promoter elements (in addition to the promoter incorporated in the recombinant retrovirus) which are responsible for the transcription of the Bmx gene, can be used. For example, a construct in which there is an additional promoter modulated by an external factor or cue can be used, making it possible to control the level of polypeptide being produced by the endothelial cells by activating that external factor or cue. Transduction performed in vivo involves applying the recombinant retrovirus encoding Bmx sense or antisense DNA to the desired endothelial cells by, e.g., site directed administration of recombinant retrovirus into a blood vessel via a catheter. Alternatively, endothelial cells that have been transduced in vitro can be grafted onto a blood vessel in vivo through the use of a catheter. The isolation and maintenance of endothelial cells from capillaries and large vessels (e.g., arteries, veins) of many species of vertebrates have been well described in the literature. For example, McGuire and Orkin describe a simple procedure for culturing and passaging endothelial cells from large vessels of small animals. McGuire and Orkin (1987) Biotechniques, 5:546-554.
[0052] The practice of the present invention generally employs conventional techniques of molecular biology, microbiology, recombinant DNA, and immunology, which are well within the skill of the art. Such techniques are explained fully in the literature. See for example J. Sambrook et al, “Molecular Cloning; A Laboratory Manual (1989); “DNA Cloning”, Vol. I and II (D. N Glover (ed.) 1985); “Oligonucleotide Synthesis” (M. J. Gait cd, 1984); “Nucleic Acid Hybridization” (B. D. Hames & S. J. Higgins eds. 1984); “Transcription And Translation” (B. D. Hames & S. J. Higgins eds. 1984); “Animal Cell Culture” (R. I. Freshney ed. 1986); “Immobilized Cells And Enzymes” (IRL Press, 1986); B. Perbal, “A Practical Guide To Molecular Cloning” (1984); the series, “Methods In Enzymology” (Academic Press, Inc.); “Gene Transfer Vectors For Mammalian Cells” (J. H. Miller and M. P. Calos eds. 1987, Cold Spring Harbor Laboratory); Meth Enzymol (1987) 154 and 155 (Wu and Grossman, and Wu, eds., respectively); Mayer & Walker, eds. (1987), “Immunochemical Methods In: Cell And Molecular Biology” (Academic Press, London); Scopes, and “Handbook Of Experimental Immunology,” volumes I-IV (Weir and Blackwell, eds, 1986). The disclosures of all of the above references are incorporated herein by reference.
[0053] The present invention also encompasses pharmaceutical compositions which include a Bmx tyrosine kinase regulating agent identified using the above-described methods. These compositions include a pharmaceutically effective amount of the agent in a pharmaceutically acceptable carrier or diluent. Acceptable carriers or diluents for therapeutic use are well known in the pharmaceutical art, and are described, for example, in Remington's Pharmaceutical Sciences. 18th ed., Gennaro, ed., Mack Publishing Company, Easton, Pa., 1990, herein incorporated by reference. Preservatives, stabilizers, dyes and even flavoring agents may be provided in the pharmaceutical composition. For example, sodium benzoate, sorbic acid and esters of p-hydroxybenzoic acid may be added as preservatives. In addition, antioxidants and suspending agents may be used.
[0054] Compositions containing agents for use in the present invention may be formulated and used as tablets, capsules or elixirs for oral administration, suppositories for rectal administration, sterile solutions, suspensions for injectable administration, and the like. The formulations of this invention can be applied for example by parenteral administration, intravenous, subcutaneous, intramuscular, intracranial, intraorbital, ophthalmic, intraventricular, intracapsular, intraspinal, intracistemal, intraperitoneal, intranasal, aerosol, or oral administration. Injectables can be prepared in conventional forms, either as liquid solutions or suspensions, solid forms suitable for solution or suspension in liquid prior to injection, or as emulsions. Suitable excipients are, for example, water, saline, dextrose, mannitol, lactose, lecithin, albumin, sodium glutamate, cysteine hydrochloride, and the like. In addition, if desired, the injectable pharmaceutical compositions may contain minor amounts of nontoxic auxiliary substances, such as wetting agents, pH buffering agents, and the like. If desired, absorption enhancing preparations (e.g., liposomes) may be utilized.
[0055] The pharmaceutically effective amount of the composition required as a dose will depend on the route of administration, the type of animal being treated, and the physical characteristics of the specific animal under consideration. The dose can be tailored to achieve optimal efficacy but will depend on such factors as weight, diet, concurrent medication and other factors which those skilled in the medical arts will recognize. Typically, human clinical applications of products are commenced at lower dosage levels, with dosage level being increased until the desired effect is achieved. The determination of effective dosage levels, that is the dosage levels necessary to achieve the desired result, will be within the ambit of one skilled in the art based on generally accepted protocols for clinical studies.
[0056] In practicing the methods of the invention, the Bmx tyrosine kinase regulating agents can be used alone or in combination with one another, or in combination with other therapeutic or diagnostic agents, employing a variety of dosage forms.
EXAMPLE 1
Isolation and Analysis of Mouse Bmx cDNA Clones for In Situ Hybridization
[0057] Mouse Bmx cDNA was isolated, sequenced and found to encode a protein approximately 91% identical with the human Bmx tyrosine kinase. Northern blotting and in situ hybridization of sections indicated that Bmx mRNA is specifically expressed in the endocardium of the developing heart, endocardium of the left ventricle in adults and in the endothelium of large arteries. Approximately 1×10 6 bacteriophage lambda clones from a 12 day p.c. mouse embryo cDNA library (Novagen) were screened with a radiolabeled Bam HI fragment (nt 192-1831) of human Bmx cDNA (sequence accession number X83107). One positive clone containing about 1.7 kb including or containing the open reading frame and 3′ untranslated sequence as well as a polyA sequence, was isolated and subcloned as three fragments, which were sequenced from both strands. The remaining 5′ portion of the cDNA was obtained by isolating the first Bmx coding exon from a mouse genomic DNA library in the lambda FIXII vector (Stratagene), using a PCR fragment containing human Bmx nucleotides 23 to 162 as a probe. Primers were designed on the basis of the obtained sequence for PCR amplification of the remaining part of mouse cDNA using mouse heart Quick-Clone cDNA (Clontech) as the template. The PCR reaction conditions were: denaturation at 94° C. for 60 s, annealing at 50° C. for 30 s and extension at 72° C. for 30 s, for 30 cycles in a reaction volume of 50 μl. The PCR fragment obtained was subcloned into the pCRII vector (Clontech) and sequenced. Two independent amplifications and clonings were carried out from the same cDNA using the Dynazyme polymerase (Finnzymes).
[0058] The mouse Bmx cDNA structure and the isolated clones are shown schematically in FIG. 1A . The human BMX cDNA is shown in SEQ. ID NO.: 1. The location of the different protein domains encoded by the cDNA as well as translational start and stop codons and polyadenylation signal are marked in the figure. A comparison of the deduced amino acid sequences of mouse (SEQ. ID. NO.: 2) and human Bmx (SEQ. ID. NO.: 3) genes is shown in FIG. 1B . Comparison of the degree of sequence identity with other members of the Btk/Emt/Tec/Txk/Bmx TK family allowed an unequivocal identification of the clone as the homologue of human Bmx (data not shown).
EXAMPLE 2
Analysis and Localization of Bmx mRNA Expression in Tissues
[0059] A Northern blot containing 2 μg of polyadenylated RNAs from various mouse tissues (Clontech) was hybridized with the Bmx cDNA fragment probe and washed under stringent conditions, according to the manufacturer's instructions.
[0060] The mouse Bmx antisense and sense RNA probes were synthesized from linearized pBluescript II SK+ plasmid (Stratagene, La Jolla, Calif.), containing a Hind III-EcoRI fragment from mouse Bmx cDNA (nucleotides 1302-2369; Genbank accession number X83107, by incorporation of [35S]-UTP using T7 and T3 polymerases after linearization with Eco RI and Hind III, respectively. In situ hybridization of paraffin sections was performed as previously described (Kaipainen et al. (1993) J Exp Med 178:2077-2088).
[0061] When mouse Bmx cDNA was used to probe a Northern blot containing polyA+ RNA from various mouse tissues, clearcut mRNA signals were obtained only from the heart and lung ( FIG. 1C ).
[0062] Sections of mouse embryos and adult tissues were processed for in situ hybridization using mouse Bmx cDNA as the probe. The 8.5 day and 9.5 day mouse embryos were negative for Bmx mRNA. In 10.5 and 12.5 day p.c. mouse embryos the Bmx autoradiographic signals decorated the heart endocardium ( FIG. 2 ). Both ventricular and a trial endocardium were positive for Bmx mRNA. In addition, the endothelium of the dorsal aorta showed a strong hybridization signal, whereas the cardinal vein was negative. No other cells were positive for Bmx mRNA in the embryonic sections.
[0063] In transverse sections of the thoracic cavity, strong Bmx mRNA signals were also present in the aortal endothelial cells and subclavian arteries as well as in the intervertebral arteries ( FIG. 3A and B). Signal was seen also in the umbilical arteries (C, D). Such signals were considerably weaker, but persisted, in the aortic endothelium of 16.5 day mouse embryos (E, F). The Bmx sense probe did not give a signal in any of these sections (G,H).
[0064] Adult mouse lung and kidney were negative for Bmx mRNA in situ hybridization, but autoradiographic signals were obtained from the heart endocardium of the left ventricle and from aorta (J,K). Interestingly, the right ventricular endocardium was negative (data not shown) and also the coronary arteries showed a weak but definitive hybridization signal (L,M).
[0065] These data show for the first time expression of the Bmx tyrosine kinase, a member of the Btk/Emt/Tec/Txk/Bmx tyrosine kinase family, outside the hematopoietic system. We have previously shown that the Bmx gene is expressed in bone marrow cells, CD34+ hematopoietic cells from umbilical cord blood and in peripheral blood granulocytes (Tamagnone et al. (1994) Oncogene 9:3683-3688, herein incorporated by reference; Kaukonen et al. (1996) B J Haematol 94:455-460). Although the Tec TK has been reported to be expressed in hepatocytes and hepatomas, (Mano et al. (1990) Oncogene 5:1781-1786) previous studies have indicated that the Btk/Emt/Tec/Txk/Bmx TKs function mainly in certain lineages of hematopoietic cells, where they are activated by several upstream signal transducers (Vihinen and Smith, supra).
[0066] In addition, recent data indicate that the PH domain of Btk interacts with specific phospholipids, (Tsukada et al. (1994) Proc Natl Acad Sci USA 91:11256-11260) and such binding may be modulated by lipid kinases and phosphatases activated during receptor mediated signal transduction in these cells. In addition, a number of cytokine receptors including c-kit, GCSF, interleukin-3 and erythropoietin receptors were shown to increase tyrosine phosphorylation of Btk/Tec type of kinases (Miyazato et al.,(1995) Oncogene 11:619-625; Rawlings and Witte, (1995) Seminars in Immnunology 7:237-246; Miyazoto et al., (1996) Cell Growth and Differentiation 7:1135-1139; herein incorporated by reference). In addition, thrombin receptor, which is coupled to G-protein mediated signal transduction was shown to stimulate phosphorylation of the Tec kinase related to Bmx in platelets (Hamazaki et al. (1998) Oncogene 16:2773-2779; herein incorporated by reference). Recent experiments have indicated that one of the downstream components of the Bmx signal transduction pathway is the Stat transcription factor (Saharinen et al. (1997) Blood 11:4341-4353).
[0067] The expression of the Bmx gene apparently begins around day 9.5-10.5 of mouse embryonic development, but it was not restricted to embryonic tissues. BMX transcripts were also identified in adult mouse heart and lung by Northern hybridization. On the basis of the present in situ hybridization results, the mRNA signal in the lung sample is derived from the large arteries present in this material. The signal in the heart sample was considered to be derived from the adult endocardium. Interestingly, the coronary arteries also showed a weak, but definitive BMX mRNA signal.
EXAMPLE 3
The Bmx Tyrosine Kinase is Regulated by Vascular Endothelial Growth Factor Receptor (VEGFR) and Cytokine Receptors
[0000] Materials and Methods:
[0068] The polyclonal antibody (Ab) against human Bmx was produced against the Tec Homology (TH) domain by Dr. Toshio Suda (amino acids 151-169, NH2-CNLHTAVNEEKHRVPTFPDR—COOH (SEQ. ID. NO.: 4)). The monoclonal anti-hemagglutinin (HA)-epitope Ab, phosphotyrosine Ab, and anti-CD31 Ab were from Berkeley Antibody Company (Richmond, Calif.), from Transduction Laboratories and from DAKO, respectively. GCSF growth factor was a kind gift from Dr. Riitta Alitalo, while VEGF was obtained from R&D Systems, Minneapolis, Minn. VEGF-B was produced in Drosophila cells by Terhi Karpanen. Mouse IL-3 was obtained from Calbiochem Novabiochem. Phosphatidyl inositol-3 kinase inhibitors Wortmannin and LY294002, were both from Sigma. For inhibition of PI3K activity, 100 nM for 30 min of Wortmannin and 100 μM of LY294002 for 30 min, were used.
[0069] DNA constructs were made as follows. Carboxy terminus HA tagged human full-length Bmx cDNA was cloned into the Mlu I-Sal I sites of the pCI-neo expression vector (Saharinen et al. 1997 Blood 11:4341-4353). The kinase dead form of human Bmx, BmxHA K444R, was generated by site specific mutagenesis, using GeneEditor (Promega) kit, 5′-TGTTGCTGTTAGGATGATCAAGG-3′ (SEQ. ID. NO.: 5) as primer and human full-length Bmx cDNA in pCI neo expression vector, as template.
[0070] Human GCSFR cDNA cloned into the pEF-BOS expression vector was a kind gift from Dr. Shigekazu Nagata via Dr. Judith Layton. The cDNAs for human VEGFR-1 and VEGFR-3 were cloned into pcDNA3.1 Z+ (Invitrogen). The expression plasmid for VEGFR-2 was a kind gift from Dr. Bruce Terman, while the cDNA for EpoR, cloned into pRK5 expression vector, was a gift from Dr Olli Silvennoinen.
[0071] Cell culture and transfections. 293T cells were grown in Dulbecco's Modified Eagle's Medium (DMEM), Human umbilical vein endothelial cells (HUVECs) were maintained in Hy-clone 199 medium. 32Dcl3 cells, a gift from Dr. Olli Silvennoinen, were maintaied in RPMI 1640 medium, containing 2 ng/ml mouse IL-3. All media were supplemented with 10% fetal calf serum, glutamine and antibiotics, the Hy-clone 199 medium additionally with endothelial cell growth supplement-ECGS (Upstate Biotechnology). Where indicated, cells were stimulated with growth factors, hGCSF 100 ng/ml, hVEGF and VEGF-B 60 ng/ml, for 5 min or with mIL-3 or hIL-3, 200 ng/ml, for 30 min.
[0072] Transfections and generation of stable BmxHA and BmxHA K444R expressing pools (and clones). Transient co-transfections of293T cells were done using the Calcium Phosphate Transfection kit (GIBCO) according to manufacturer's instructions. The cells were transfected with Bmx-HA expression plasmid and the receptor plasmid or empty vector (PCI-Neo or pcDNAZ3.1) in the ration of 1:4. 30 h after transfection cells were switched to serum-free medium containing 0.2% BSA and the next day lysed in PLCLB or TKB kinase assay lysis buffer. Stable BmxHA and BmxHA K444R expressing 32Dcl3 cells were generated by electroporation (240 mV, 960 μF) followed by selection in 500 μg/ml neomycin.
[0073] Immunoprecipitation and Western blotting were performed as follows. The cells were lysed in PLCLB lysis buffer (50 mM HEPES, 150 mM NaCl, 10% Glycerol, 1% Triton X-100, 1.5 mM MgCl2) supplemented with aprotinin, leupeptin, phenylmethylsulfonyl fluoride (PMSF) and sodium vanadate. Equal amounts of protein from cell lysates were used for the immunoprecipitation. Protein concentrations of the lysates were measured using the BioRad Protein Assay system (Bio-Rad Laboratories, Hercules, Calif.). Immunoprecipitation of the lysates was performed by incubation with indicated antibody for 1 to 2 hours followed by binding to protein-G-Sepharose (Pharmacia) or protein-A-Sepharose (Sigma) for 30 min to 1 hour with gentle agitation. The immunoprecipitates were washed, eluted in Laemmli buffering, electrophoresed in 7.5% SDS-PAGE and blotted onto a nitrocellulose filter. Immunodetection was performed using specific primary antibodies and HRP-conjugated anti-mouse or anti-rabbit secondary antibodies (Dako) followed by ECL detection (Amersham).
[0074] In vitro substrate immunocomplex kinase assay was performed as follows. The cells were lysed in TKB lysis buffer (1% NP-40, 20 mM Tris-HCl (pH 7.5), 150 mM NaCl, 5 mM EDTA), supplemented with aprotinin, leupeptin, PMSF and sodium vanadate. Immunoprecipitation was performed as described above. After precipitation, the immunoprecipitates were washed two times with lysis buffer, one time with wash buffer (150 mM NaCl, 20 mM HEPES pH 7.4) and two times with kinase assay buffer (10 mM HEPES pH 7.4, 5 mM MnCl 2 , sodium vanadate), after which they were resuspended in 5 μl of reaction buffer (1× kinase assay buffer, 5 μM unlabeled ATP, 3 μCi gamma-ATP, 2.5 μg poly (Glu, Tyr) (Sigma)). The kinase reactions were carried out at 30° C. for 10 min and stopped by adding 50 μl of stopping buffer (4 mM unlabeled ATP, 40 mM EDTA, 20 mM HEPES pH 7.4, 100 μg BSA). The sepharoses were spun down and the substrate containing supernatants were spotted on Whatman 3MM filter papers. The filters were fixed and washed one time in 10% TCA 8% sodium pyrophosphate, 3 times in 5% TCA and 2 times in ethanol after which radioactivity was measured using Pharmacia Wallac 1410 Liquid Scintillation Counter. For detection of autokinase activity, the sepharose was eluted in Leammli buffer, and separated in 7.5% SDS-PAGE. The gel was dried and Bmx autokinase activity was detected by exposure on film.
[0000] Results:
[0075] Phosphorylation of kinase dead Bmx by Jak kinases. Kinase dead Bmx was coexpressed with Jak1 or Jak2 in 293T cells. FIG. 4 shows that Jak2, and in a lesser extent, Jak1 phosphorylate kinase dead Bmx.
[0076] EpoR, GCSFR and Flt1 induce Bmx phosphorylation in 293T cells ( FIG. 5 ). When Bmx was coexpressed in 293T cells together with EpoR or GCSFR, a clear phosphorylation of Bmx could be detected. Also Flt1 phosphorylated Bmx, although in a smaller amount, while no increase in phosphorylation level could be detected after coexpression with KDR or Flt4. A phosphorylated protein of approximately 100 kD was co-precipitated with the phosphorylated Bmx. All cells were starved in 0.2% BSA over night before lysis. Note that exposure time for Flt1, KDR and Flt4 total lysates are longer than to the corresponding other receptors, in order to detect these receptors.
[0077] Coexpression of Bmx and VEGFR-1, EpoR or GCSFR in 293T cells increases kinase activity of Bmx. As can be seen from FIG. 6 , when Bmx was coexpressed in 293T cells together with indicated receptors, a clear activation of both substrate (poly (glu-tyr)) kinase activity ( FIG. 6A ) and autokinase activity ( FIG. 6B ) could be detected after expression with EpoR, GCSFR and Flt1, while KDR and Flt4 did not activate Bmx. The Bmx levels were same in all reactions as determined by the anti-Bmx blot ( FIG. 6C ). FIG. 7 shows a comparison of Bmx activity after co-transfection of Bmx and VEGF receptors.
[0078] IL-3 and GCSF increase Bmx kinase activity in 32Dcl3 cells using endogenous IL-3 and GCSF receptors. In FIG. 8 , BmxHA or kinase dead (K444R) Bmx expressing 32Dcl3 pools, were stimulated with IL-3, GCSF or were left unstimulated. IL-3 increased the kinase activity of Bmx about 2.2 fold, while the increase after GCSF stimulation was around 1.7. Kinase dead mutation of Bmx only showed background activity. The same amount of total protein (120 μg) was used for all immunoprecipitations. Cells were starved in IL-3 and serum free media for 14 hours before lysis.
[0079] Activation of endogenous Bmx. Human Umbilical Vein Endothelial Cells (HUVECs) were stimulated with VEGF, VEGF-B or IL-3, and kinase activity of Bmx was measured. FIG. 9 A and B show that stimulation with Flt1 activating factors, VEGF and VEGF-B, increased endogenous Bmx activity in the same way as in transfected 293T cells. As in 32Dcl3 cells, also IL-3 increased Bmx kinase activity in HUVECs. PI3K inhibitors Wortmannin, and to a less extence LY294002 (2-(4-morpholinyl)-8-phenyl-4H-1-benzopyran-4-one), were able to block the activation. FIG. 9C , control blotting with endothelial specific anti-CD31 to confirm equivalent amounts of total protein in each reaction.
[0080] Together, these results show that the receptors for erythropoietin, vascular endothelial and granulocyte growth factors activate Bmx tyrosine kinase in conditions of overexpression in 293T cells. The receptors for vascular endothelial growth factors 2 and 3 were not able to activate Bmx. The overexpressing conditions in 293T cells presumably activate the receptors similar to ligand binding. In addition, endogenous Bmx in HUVECs was activated after stimulation with VEGF and VEGF-B, both ligands of Flt1 receptor, showing that the activation seen in 293T cells is not due to the overexpression. In HUVECs an inhibition of the activation of Bmx could be detected after use of PI3K inhibitor Wortmannin. Similar results were obtained with LY294009. These results suggest that Bmx is involved in many different types of signal transduction, at least GCSF, VEGF and IL-3 signaling. The activation of Bmx from EpoR is most probably due to the use of Jak2 as an primarily signal transducer of the receptor. Our results so far suggest that Jak tyrosine kinases are important for the activation of Bmx, which could explain the activation detected also from EpoR, even though EpoR and Bmx are not endogenously expressed in the same cells. The increase in Bmx kinase activity after coexpression with GCSFR or after stimulation with GCSF, is highly interesting, because GCSF is the most widely used growth factor for patients whose bone marrow function is compromised. Also the specific activation of Bmx by VEGFR-1 (Flt1) but not from other VEGF receptors in an interesting finding.
EXAMPLE 4
Inactivation of the BMX Gene and Generation of BMX Deficient Mice
[0081] The mouse Bmx gene was cloned from a mouse 129SV genomic DNA library using the human Bmx cDNA fragment consisting of nucleotides 23-162 as the hybridization probe for screening the bacteriophage lambda library. The region surrounding the first coding exon was characterized by restriction digest mapping. Suitable fragments flanking the first coding exon (containing the ATG initiation codon) were isolated and used to construct the targeting vector containing the LacZ and neomycin resistance cassettes employing the strategy described by Puri et al. (Puri et al. 1995 EMBO J. 14: 5884-5891; herein incorporated by reference). For negative selection, the herpes simplex virus tymidine kinase (HSV-tk) casette is included in the 3′ end of the construct. The targeting construct, shown schematically in FIG. 10 , replaces the first coding exon containing the ATG initiation codon and should thereby abolish expression of the gene upon homologous recombination in embryonic stem (ES) cells.
[0082] Transfection of mouse ES cells with the targeting constructs and screening of single clones by Southern blotting was done using standard procedures. Upon Southern blotting and hybridization using the fragments indicated in FIG. 10A , the successfully targeted clones and Bmx genes could be identified. Probe 1 consists of a 3′ internal XmnI fragment, while probe 2 was a 5′ external XbaI fragment. Analysis of 164 clones indicated that the homolougus transfection efficiency was found to be about 5.5%. Seven positive clones plus two non homologous recombined clones were grown up for aggregation with wild type ES cells in order to generate chimeric mice using methods standard in the art. These mice are screened for germline transmission and mated with wild type mice. Due to the X chromosomal location of Bmx, both heterozygous female mice, as well as nullizygous male mice can be generated.
[0083] Collectively, these data show that Bmx is involved in the physiology of endothelial cells located at sites of great fluid shear/pressure stress. Bmx is involved in relaying endothelial cell related signals in endocardial and arterial endothelial cells. Alteration of such signals can be used to lead to a long-term readjustment of gene expression in the affected cells with secondary effects in the surrounding smooth muscle cells and extracellular matrix.
[0084] The preceding description has been presented with reference to presently preferred embodiments of the invention. Workers skilled in the art and technology to which this invention pertains will appreciate that alterations and changes in the described embodiments may be practiced without meaningfully departing from the principal, spirit and scope of this invention. Accordingly, the foregoing description should not be read as pertaining only to the precise embodiments described and illustrated in the accompanying drawings, but rather should be read consistent with and as support to the following claims which are to have their fullest and fair scope. | Vascular endothelia are subject to atherosclerotic and arteriostenotic effects transduced by molecules, such as thrombin, IL-3 and VEGF which can lead to vessel occlusion or stenosis. An endothelial signaling pathway involving the Bmx tyrosine kinase contributes to normal endothelial nonthrombogenic, inflammatory and growth conditions of arterial vessels, and regulation of the pathway can treat or prevent pathological conditions in the vessel walls. | 0 |
BACKGROUND OF THE INVENTION
[0001] A. Field of the Invention
[0002] The present invention relates generally to a system that monitors the condition of hydraulic systems for an aircraft or for other applications and, more particularly, to a system and method for detecting leakage within the hydraulic system aboard an aircraft. Such system is detecting hydraulic liquids by extended sensors based on the collapse of percolation conductivity (COPC) which sensors are covering an area in the aircraft. Several documents are cited throughout the text of this specification. Each of the documents herein (including any manufacturer's specifications, instructions etc.) are herby incorporated by reference; however, there is no admission that any document cited is indeed prior art of the present invention.
[0003] B. Description of the Related Art
[0004] Aircraft hydraulic systems can be a challenge to design engineers, due to many constraints that are not encountered when designing a system for fixed or other mobile applications. Hydraulic technology first appeared in aircraft flight control after World War II, when fluid power was introduced for the control of some secondary systems. Nevertheless, as aircraft flight performance and capabilities increased, hydraulics began to play a larger role in the critical operation and safety of airliners, helicopters, and military aircraft.
[0005] Typically the hydraulic systems of an aircraft comprises a pressurized reservoir and a hydraulic circuit containing a desired amount of hydraulic fluid. Some of the places that hydraulics come into play include primary flight controls, landing gear, flap/slat drives, nose wheel steering, thrust reversers, spoilers, rudders, cargo doors, and emergency hydraulic-driven electrical generators. Factors that must be addressed on an aircraft include pressure conditions (both internal and ambient), temperature extremes, weight, speed, materials, reliability, fluid compatibility, leaks, cost, noise, and redundancy. While such systems are generally quite reliable, it is possible that they can and will lose fluid over time. Loss of fluid can result in system dysfunction, component failure and unscheduled maintenance.
[0006] It is typical that loss of hydraulic fluids starts at pinhole cracks. Due to the high pressure, the hydraulic liquid is transformed into an aerosol that pollutes the air in the respective compartments. This process is comparable with the vaporization of liquids by sprays nozzles. While periodic inspection of the hydraulic system is desirable, it would also be advantageous to automatically detect the loss of hydraulic fluid at a very early stage in order to monitor system health and conduct required maintenance, before more serious problems occur. Even with redundant systems, hydraulic leaks still pose problems to the safe operation of aircraft and have even resulted in the direct injury of passengers (via fluid spilled on to them).
[0007] Leakage of hydraulic liquids through cracks and other kinds of structural damage will have severe consequences. The loss of essential amounts of hydraulic liquid will result in failure of the hydraulic system and with it, acute danger for aircrafts operation exists. Furthermore, hydraulic liquids are known to be harmful for different kind of structural materials used in aircraft, last but not least most of these compounds are irritating for human skins and the respiratory tract. Last but not least, hydraulic liquid leaving pinhole cracks at high pressures are dangerous because they are able to injure human bodies just by the high velocity of the aerosol beam leaving the tube. However, if monitoring technologies are in place providing continuous information on the presence of leaked hydraulic liquids, repair of the structural elements can start at a very early stage.
[0008] In nowadays maintenance operation, leakage of hydraulic liquids can in some sections be monitored by visual inspection. However, there are hidden spaces that are difficult to access. Problems with hydraulic leakage can be detected only at regular heavy inspections or when leakage gets obvious, when hydraulic liquids enter the passenger cabin during aircraft operations (Brussels Airlines incident in November 2009). A monitoring system would thus essentially enhance passenger's safety and enable huge cost savings when the presence of leaked hydraulic liquids could be detected at a very early stage. The challenge for inspection is that always hidden space difficult to access and finally the difference between baseline variations at normal operations and the signals after leaking hydraulic liquids, the price of the instrumentation, certification issues etc. A related patent (U.S. Pat. No. 6,717,664) proposes an optical fibre system to enable the use of a boroscope for inspecting longer distances in the hidden space of the floor beam area of aircraft. However, this would nevertheless require time-consuming manual inspections and probably not all surfaces would be visible. Furthermore, at the first steps of leakage, liquids are dispersed into an aerosol due to the high pressure difference between the outside and the inside of the hydraulic tube.
[0009] Currently, sensors are frequently used to monitor hydraulic system operation. In the case of a car or truck, a sensor can be used to monitor the pressure the system is applying to the brake lines. In the case of aircraft, they are typically more complex sensor systems including, for example, a quantity gauge to measure the quantity of fluid in the low pressure reservoir chamber, a pressure transducer and a temperature transducer.
[0010] However the current protocols for leak detection in the hydraulic systems require the aircraft to be running, since changes in pressure in the system are used to determine if there is a leak is indeed present within the system.
[0011] Recent developments in the field focus on improving the current sensor setup that already is in place. An example of this is patent U.S.2010030496, in which a real-time hydraulic pressure surveillance system ensures that leaks are detected in a timely manner and offers a prognostic ability to foresee future fluid levels. This still requires the need for the hydraulic system to be running and it would require some form of calibration for best monitoring results. The use of pre-determined control values could be employed, yet a level of tolerance and variability between aircraft of the same type exists, due to maintenance history as well as flight history. In addition, the number of leaks do increase with the age of the aircraft. Therefore the system would need to be calibrated for each aircraft to be an effective system. Furthermore, although it can predict future drops of fluid levels, it does not necessarily indicate where a leak will occur or is occurring.
[0012] Leakage of hydraulic liquids through cracks and other kinds of structural damage will have severe consequences. In nowadays maintenance operation, leakage of hydraulic liquids is in some sections monitored by visual inspection. However, there are hidden spaces that are difficult to access. In this context, inaccessible tubes are sometimes surrounded by a shroud system making that leaked hydraulic liquid flows into sections where it is less harmful and where its presence can be visually detected. However, those shrouds are expensive to install when not yet available and small amounts leaving the system at very fine hair cracks will remain undiscovered because the hydraulic liquid leaves the tube as an aerosol due to the high pressure inside the tube (the pressure can range up to several hundreds bar). A reliable sensor for hydraulic liquids which is frequently interrogated could help to reduce the danger of pressure drop in hydraulic systems and incidents when hydraulic liquids come in contact with passenger area.
[0013] There exist other detection systems which are based on visual recognition of the leak. This is possible with the addition of a dye to the hydraulic fluid. The advantage of this method is the quick identification of the leak itself and the low cost. Useful for areas that are easily accessible (such as the landing gear). The disadvantage is if the leak occurs in a location which is not readily accessible. Therefore, the only means to find such a leak is through a full inspection of the aircraft or when already troubleshooting a drop in hydraulic pressure.
[0014] The main issues with current detection systems (and their improvements) is their basis on measuring the hydraulic fluid itself, either in difference of pressure or amount, or through visual identification, or a combination of both. In addition, some of these detection systems can add complexity and might require non-trivial modification of the hydraulic system if installed.
[0015] Thus, there is a need in the art for a method to detect leaks in the hydraulic system, which would allow for the required maintenance to be done when needed, without the need for major modifications to the hydraulic system itself and to be easy to implement and not require the aircraft to be functioning.
[0016] In the present invention, which provides a means to detect hydraulic liquids by extended sensors (covering a larger area) based on the collapse of the percolation conductivity (COPC) of a composite comprising a conducting compound which is embedded in a matrix that is solvable in the respective hydraulic liquid, provides the advantage that it can sense.
[0017] The components are mixed in an appropriate ratio, resulting in a composition so that the composite is above the percolation threshold.
[0018] When this composite is exposed to hydraulic liquids, the system takes up liquid until the conductivity is essentially lost. The increase of the resistance due to the ingress of hydraulic liquid can be monitored by a digital multi-channel multimeter that is equipped with appropriate data logging facilities.
[0019] The applicability of the integral system of present invention is in situ continues, or under frequently interrogation sense hydraulic deficiencies on any for inspection difficult accessible space without the requirement to have the hydraulic system to be running and without the need of calibration for best monitoring results. Such system can at any moment reduce the danger of pressure drop in hydraulic systems and incidents when hydraulic liquids come in contact with the passenger area.
SUMMARY OF THE INVENTION
[0020] The present invention solves the problems of the related art by using a system to detect leakage, based on the percolation threshold of a conducting compound in a hydrophilic matrix.
[0021] The present invention concerns an aircraft an improved landing or taking off security means, characterised in that the aircraft comprises a gauge whereby the gauge comprises a sensing material surrounding at least part of the hydraulic conduits of said aircraft which sensing materials is a composite comprising at least two components. 1) particles or powder of an electrically-conductive material dispersed in 2) a matrix that is highly solvable to aircraft hydraulic fluid whereby the concentration, dispersity and/or orientation of the electrically-conductive particles are tailored to be in the proximity of the percolation threshold in a way that the composite itself is still in the electrically-conductive state under normal aircraft operations and that the percolation conductivity is essentially interrupted after entering of aircraft hydraulic fluid into the composite. The conductivity of the sensing material can be interrupted as consequence of the absorption of the aircraft hydraulic fluid into the matrix embedding the electrically-conductive material powder or particles by transition through the threshold of percolation conductivity (collapse of percolation conductivity, COPC) into the non-conductive state.
[0022] In a particular embodiment, the aircraft hydraulic fluid in said aircraft is a phosphate-ester based aircraft hydraulic fluid, for instance the aircraft hydraulic fluids is of the group consisting of BMS 3-11: Skydrol 500B-4, Skydrol LD-4, Skydrol 5 and Exxon HyJetIV-A plus. This embodiment of the invention advantageously the aircraft hydraulic fluids is Skydrol® 500 B. furthermore in this embodiment advantageously the conductive particles are of the group consisting metal particle, a particle coated by said metal, a carbon black particles or particles of conductive ceramics or the metal particle is nickel, cupper or silver or a particle coated with nickel, cupper or silver. This embodiment of the invention advantageously the matrix is an acrylic resin. This acrylic resin can comprise methyl methacrylate monomer (MMA) and or Polymethyl methacrylate (PMMA). In an advantageous embodiment, the aircraft according to the present invention comprises a gauge, whereby the composite comprises nickel powder in acrylic matrix.
[0023] Some of the techniques described above may be embodied as that in the gauge after exposure to hydraulic liquid the resistance in the composite increases which can be displayed on a screen after processing in that the curve of resistance (Ohm) vs. time (min) shows an increase in the resistance.
[0024] According to the present invention there is also provided an aircraft an improved landing or taking off security means, characterised in that the aircraft comprises an aircraft hydraulic liquid leakage monitor for real-time and detecting of aircraft hydraulic liquid leakage in situ from the aircraft hydraulic system the monitor, comprising: a tape, sheet or fabric [ 2 ] accessible for aircraft hydraulic liquid (such as Skydrol® 500 B) that is winded with isolating spacers around the hydraulic tube [ 1 ] to be sensed which tape, sheet or fabric comprises or is impregnated with a sensing material that comprises a composite comprising at least two components. 1) particles or powder of an electrically-conductive material dispersed in 2) an matrix that is highly solvable to aircraft hydraulic fluid whereby the concentration, dispersity and/or orientation of the electrically-conductive particles are tailored to in a way that the composite itself is normally in the electrically-conductive state but has the percolation conductivity interrupted after entering of aircraft hydraulic fluid into the composite [ 2 ] and further comprising electrodes [ 4 ] for measuring resistance in sensing material [ 2 ]. This aircraft hydraulic liquid leakage monitor of the aircraft of present invention has the sensing tape, sheet or fabric [ 2 ] surrounding or s winded around the hydraulic tube [ 1 ] of at least part of the hydraulic system such to capture into the sensing materials the leaked hydraulic liquids that are otherwise dispersed into an aerosol due to the high pressure difference between the outside and the inside of the hydraulic tube. Some of the techniques described above may be embodied as that the matrix does not resist an attack by aviation hydraulic fluid in the hydraulic aircraft system whereby in a specific embodiment that the matrix does not resist an attack by or contact with aviation phosphate ester fluids.
[0025] Some of the techniques described above may be embodied as that the conductivity of the sensing material is interrupted as consequence of the absorption of the aircraft hydraulic fluid into the matrix embedding the electrically-conductive material powder or particles by transition through the threshold of percolation conductivity (collapse of percolation conductivity, COPC) into the non-conductive state. Thus, in certain embodiments of the present invention, the aircraft hydraulic liquid leakage monitor according to any one of the embodiments above comprises a matrix does not resist an attack by or contact with a phosphate-ester based aircraft hydraulic fluid, for instance it does not resist an attack by or contact with aircraft hydraulic fluids of the group consisting of BMS 3-11: Skydrol 500B-4, Skydrol LD-4, Skydrol 5 and Exxon HyJetIV-A plus or it concerns a matrix that does not resist an attack by or contact with aircraft hydraulic fluid, Skydrol® 500 B.
[0026] In an advantageous embodiment, the aircraft hydraulic liquid leakage monitor according to any one of the embodiments to the present invention comprises conductive particles are of the group consisting metal particle, a particle coated by said metal, a carbon black particles or particles of conductive ceramics. In case of a metal particle this can nickel, cupper or silver or a particle coated with nickel, cupper or silver. In an advantageous embodiment, the aircraft hydraulic liquid leakage monitor according to any one of the embodiments to the present invention comprises a matrix is an acrylic resin. Such acrylic resin can comprise methyl methacrylate monomer (MMA) and or Polymethyl methacrylate (PMMA). This invention accordingly provides the advantage that in the aircraft hydraulic liquid leakage monitor of present invention the composite comprises nickel powder in acrylic matrix.
[0027] In the aircraft of present the aircraft hydraulic liquid leakage monitor according to any one of the embodiments described above, have a display for instance a display screen which after exposure to hydraulic liquid demonstrates that the resistance in the composite increases which after can be displayed in that the curve of resistance (Ohm) vs. time (min) shows an increase in the resistance.
[0028] In a particular embodiments concerning the aircraft of present invention the the aircraft hydraulic liquid leakage monitor can have one of the following features it surrounds an hydraulic tube whereby the integral length hydraulic tube has 10 m or more than 1 m or whereby the diameter of tube has a diameter of 1 cm or more than 0.5 cm or whereby the diameter of tube has a diameter of 1 between 0.7 and 1.2 cm and whereby in an advantageous embodiment the sensing material covered surface of said such hydraulic tube is about 0.30 m 2 .
[0029] The aircraft hydraulic liquid leakage monitor in connection to the aircraft's hydraulic system according to any one of the embodiments of present invention, whereby volume to add when layers have approx. 100 micron is between 25-35 cm 3 and preferably 29-31 cm 3 .
[0030] In a particular embodiment, the aircraft hydraulic liquid leakage monitor according to the present invention has a the matrix which is an acrylic resin with a density between 0.5 to 1.5 g/cm 3 , preferably between 0.8 and 1.2 g/cm 3 , more preferably 0.9 and 1.1 g/cm 3 and most preferably around 1 g/cm 3 .
[0031] In yet another particular embodiment, the aircraft hydraulic liquid leakage monitor according to the present invention comprising a controller based on a software assisted measurement system and control algorithm. This controller can have a computer readable medium tangibly embodying computer code executable on a processor. In a particular embodiment this processor is connected to provide a control signal to an actuator configured to signal or alarm the hydraulic liquid leakage and more particular this processor can be connected to provide a control signal to an actuator configured to alert pilot or third party and yet more particular this processor is connected to provide a control signal to an actuator configured to locate the aircraft hydraulic liquid leakage defect.
[0032] In one embodiment of the invention, the aircraft hydraulic liquid leakage monitor according to any one of the embodiments described above has a controller that operates as safety fuse for leaking hydraulic liquids whereby noise (small conductance variations that occur during operations due to temperature variations, aging of adhesives etc) is disregarded by the processor but whereby an essentially loss of conductivity noise is regarded as an aircraft hydraulic liquid leakage. It may furthermore comprise a memory for storing the information signals and at least one transmitter for transmitting information signals to a base station adapted to receive information signals. This base station can be adapted to transmit interrogation signals. Furthermore the at least one transmitters can be formed by transponders which are adapted to receive the interrogation signals and to transmit information signals stored in the memory in response to receiving an interrogation signal and the monitor can be characterized in that at least one transmitter or transponder is adapted to receive and transmit signals in the ether.
[0033] Furthermore in a particular embodiment of present invention the aircraft hydraulic liquid leakage monitor according to any one of the embodiments described above is characterized in that at least the base station is adapted to receive and transmit signals via a telephone network or the transmitter or transponder is adapted for information communication via a mobile telephone network. These aircraft hydraulic liquid leakage monitor according to any one of the previous embodiments can be used to enhance passenger's safety or to detect presence of leaked hydraulic liquids at a very early stage.
[0034] Particular and preferred aspects of the invention are set out in the accompanying independent and dependent claims. Features from the dependent claims may be combined with features of the independent claims and with features of other dependent claims as appropriate and not merely as explicitly set out in the claims.
[0035] Thus, the claims following the detailed description are hereby expressly incorporated into this detailed description, with each claim standing on its own as a separate embodiment of this invention.
[0036] Further scope of applicability of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description. 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.
DETAILED DESCRIPTION
Detailed Description of Embodiments of the Invention
Definitions
[0037] In this application, the term “percolation” is assigned to the theory of connectivity of particles in randomised lattice structures. The most famous example are conductive polymers, i.e. materials that are used as electrical conducting glues or adhesives.
[0038] SKYDROL is one type of hydraulic fluid used in the aviation industry, although the current invention can be adapted for use with other fluids.
[0039] Aircraft hydraulic fluids fall under various specifications. There are the common petroleum-based such as Mil-H-5606: Mineral base, flammable, fairly low flashpoint, usable from −65° F. (−54 ° C.) to 275° F. (135° C.), red color, Mil-H-83282: Synthetic hydrocarbon base, higher flashpoint, self-extinguishing, backward compatible to −5606, red color, rated to −40° F. (−40° C.) degrees and Mil-H-87257: A development of −83282 fluid to improve its low temperature viscosity. There are the Phosphate-ester based aircraft hydraulic fluids such as BMS 3-11: Skydrol 500B-4, Skydrol LD-4, Skydrol 5 and Exxon HyJetIV-A plus—Typically light purple, not compatible with petroleum-based fluids, will not support combustion.
[0040] “In the proximity of the percolation threshold” means that the percolation conductivity is essentially interrupted if a relevant amount of solvent (harmful quantity of hydraulic liquids) has entered the composite, i.e. the disappearance of conductivity is a consequence of the absorption of the solvent into the embedding matrix (thus by transition through the threshold of percolation conductivity (collapse of percolation conductivity, COPC) into the non-conductive state).
[0041] The acrylic resin must be conductive (e.g. company: Holland shielding—conductive painting 3801) and sensitive to SKYDROL attack, or towards another type of hydraulic fluid. In addition, the acrylic resin used is of low flammability (as used in printed circuits, similar to Plexiglas frequently applied in aircraft), to conform to aircraft safety regulations. Wiring to be done with certified cables (e.g. type ASNE 0261).
[0042] The following detailed description of the invention refers to the accompanying drawings. The same reference numbers in different drawings identify the same or similar elements. Also, the following detailed description does not limit the invention. Instead, the scope of the invention is defined by the appended claims and equivalents thereof.
[0043] Several documents are cited throughout the text of this specification. Each of the documents herein (including any manufacturer's specifications, instructions etc.) are hereby incorporated by reference; however, there is no admission that any document cited is indeed prior art of the present invention.
[0044] The present invention will be described with respect to particular embodiments and with reference to certain drawings but the invention is not limited thereto but only by the claims. The drawings described are only schematic and are non-limiting. In the drawings, the size of some of the elements may be exaggerated and not drawn to scale for illustrative purposes. The dimensions and the relative dimensions do not correspond to actual reductions to practice of the invention.
[0045] Furthermore, the terms first, second, third and the like in the description and in the claims, are used for distinguishing between similar elements and not necessarily for describing a sequential or chronological order. It is to be understood that the terms so used are interchangeable under appropriate circumstances and that the embodiments of the invention described herein are capable of operation in other sequences than described or illustrated herein.
[0046] Moreover, the terms top, bottom, over, under and the like in the description and the claims are used for descriptive purposes and not necessarily for describing relative positions. It is to be understood that the terms so used are interchangeable under appropriate circumstances and that the embodiments of the invention described herein are capable of operation in other orientations than described or illustrated herein.
[0047] It is to be noticed that the term “comprising”, used in the claims, should not be interpreted as being restricted to the means listed thereafter; it does not exclude other elements or steps. It is thus to be interpreted as specifying the presence of the stated features, integers, steps or components as referred to, but does not preclude the presence or addition of one or more other features, integers, steps or components, or groups thereof. Thus, the scope of the expression “a device comprising means A and B” should not be limited to the devices consisting only of components A and B. It means that with respect to the present invention, the only relevant components of the device are A and B.
[0048] Reference throughout this specification to “one embodiment” or “an embodiment” means that a particular feature, structure or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. Thus, appearances of the phrases “in one embodiment” or “in an embodiment” in various places throughout this specification are not necessarily all referring to the same embodiment, but may. Furthermore, the particular features, structures or characteristics may be combined in any suitable manner, as would be apparent to one of ordinary skill in the art from this disclosure, in one or more embodiments.
[0049] Similarly it should be appreciated that in the description of exemplary embodiments of the invention, various features of the invention are sometimes grouped together in a single embodiment, figure, or description thereof for the purpose of streamlining the disclosure and aiding the understanding of one or more of the various inventive aspects. This method of disclosure, however, is not to be interpreted as reflecting an intention that the claimed invention requires more features than are expressly recited in each claim. Rather, as the following claims reflect, inventive aspects lie in less than all features of a single foregoing disclosed embodiment. Thus, the claims following the detailed description are hereby expressly incorporated into this detailed description, with each claim standing on its own as a separate embodiment of this invention.
[0050] Furthermore, while some embodiments described herein include some but not other features included in other embodiments, combinations of features of different embodiments are meant to be within the scope of the invention, and form different embodiments, as would be understood by those in the art. For example, in the following claims, any of the claimed embodiments can be used in any combination.
[0051] In the description provided herein, numerous specific details are set forth. However, it is understood that embodiments of the invention may be practiced without these specific details. In other instances, well-known methods, structures and techniques have not been shown in detail in order not to obscure an understanding of this description.
[0052] In the present invention, the defect in the hydraulic tubes is detected by relatively small quantities of leaking hydraulic liquids. An interrupt the electrical conductance, in a composite conducting compound, with the leaking fluid provides a signal.
[0053] Currently the most used aviation hydraulic fluid is Skydrol which is an advanced fire resistant aviation hydraulic fluid manufactured by Solutia Inc. There are various lines of Skydrol including Skydrol 500B-4, Skydrol LD-4, and Skydrol 5. Skydrol, made up of a group of chemical additives dissolved into a fire-resistant phosphate ester base stock has been approved by most airframe manufacturers including Airbus Industries, Boeing and British Aerospace and has been used in their products for over 40 years.
[0054] The applicability of the integral system could already be shown in relevant examples of the present application which for instance demonstrate the integral system for the monitoring of hydraulic deficiencies of an hydraulic systems with Skydrol® 500 B.
[0055] An appropriate matrix for the conducting composite in an embodiment of present invention is used in regards to SKYDROL (see Appendix 1/Table 1). For instance an acrylic painting offers no protection/resistance against an attack by SKYDROL (there are also other potential matrix materials). Accordingly, a conducting coating (comprising the conducting composite) based on an acrylic matrix can be used (see FIG. 1-3 ). The interruption of the conductance will be influenced by many factors. A major factor is the surface of the acrylic coating that can be attacked by SKYDROL, further factors are the temperature and the overall volume of the conducting coating.
[0056] Prior to the deposition of the sensing layer, the tubes should be coated with a non-conducting material that is sufficiently heat-resistant (approx until 120° C.) and that hat to be vulnerable to SKYDROL. This is to prevent direct contact between the conducting layer and the metallic tube. Since the relatively high temperatures in the surrounding of the tubes, traces of electrolytes are removed and the risk of galvanic corrosion is extremely limited. After this, the primer is coated with the sensing conducting acrylic coating. There could be a final non-conducting coating to protect the conducting acrylic coating.
[0057] A coat of fabric for instance a breather-bleeder can be used, that is wrapped around the tube, to absorb hydraulic liquids. The conducting coating might also be directly sprayed on the breather-bleeder. The whole set-up could finally be locked by a pressure resistant coat made of metallic tape or fibre-reinforced epoxy resin. Measurement can be performed offline (i.e. not during flight) and no additional electronics on board are needed, if so desired.
[0058] Other embodiments of the invention will be apparent to those skilled in the art from consideration of the specification and practice of the invention disclosed herein.
[0059] It is intended that the specification and examples be considered as exemplary only.
[0060] Each and every claim is incorporated into the specification as an embodiment of the present invention. Thus, the claims are part of the description and are a further description and are in addition to the preferred embodiments of the present invention.
[0061] Each of the claims set out a particular embodiment of the invention.
EXAMPLES
[0062] The defect in the hydraulic tubes is detected by relatively small quantities (less than 1 millilitres) of leaking hydraulic liquids. Such is sufficient to interrupt the electrical conductance in a conducting composite. To find the appropriate matrix for the conducting composite, the materials chart of Skydrol® was consulted. It was found that acrylic painting offers no protection/resistance against an attack by Skydrol® 500 B (there are also other potential matrix materials). Accordingly, a conducting coating based on an acrylic matrix was selected. The interruption of the conductance will be influenced by many factors. A major factor is the surface of the acrylic layer that can be attacked by Skydrol® 500 B, further factors are the temperature and the overall volume of the conducting coating.
Example 1
[0063] A piece of paper was for some seconds sprayed with conducting composite commercially available from Holland Shielding (Conductive nickel coating 3801). It is an acrylic painting containing nickel as conducting component. After a drying time of 16 hours, the resistance was measured with a digital multimeter (Keithley 2000) to be in the range of 50 Ohm. After exposing a part of the paper strip to a drop op Skydrol® 500 B (about 250 micro liters) the resistance grew sigmoidally to about 200 kOhm. After a second deposition of about 100 micro liters the resistance jumped until 100 MOhm, being the limit of the instrument. The curve shown in the diagram ( FIG. 1 ) represents a kinetic process driven by the diffusion of Skydrol® 500 B into the acrylic matrix, i.e. when changing e.g. the mass of the sample, the initial liquid amount, exposed surface etc. the curve would change its kinetic parameters.
Example 2
[0064] In a second set-up, a piece of breather bleeder (heat resistant tissue used in epoxy resin composite production) was for some seconds sprayed with conducting composite commercially available from Holland Shielding (Conductive nickel coating 3801). It is an acrylic painting containing nickel as conducting component. After a drying time of 16 hours, the resistance was measured with a digital multimeter (Keithley 2000) to be in the range of 30 Ohm. After exposing a part of the breather bleeder to a drop op Skydrol® 500 B (about 1-2 milliliters) the resistance grew essentially sigmoidally to about 100 MOhm, being the limit of the instrument. The curve shown in the diagram ( FIG. 1 ) represents a kinetic process driven by the diffusion of Skydrol® 500 B into the acrylic matrix, i.e. when changing e.g. the mass of the sample, the initial liquid amount, exposed surface etc. the curve would change its kinetic parameters.
Example 3
[0065] In a third set-up, an original hydraulic tube (British Aerosystems) was covered with wrapped paper tape (Scotch). A syringe needle was deposed under the tape to enable an insert of hydraulic liquid for testing the system. The outside of that tape was for some seconds sprayed with conducting composite commercially available from Holland Shielding (Conductive nickel coating 3801). It is an acrylic painting containing nickel as conducting component. After a drying time of 16 hours, the resistance was measured with a digital multimeter (Keithley 2000) to be in the range of 80 Ohm. After filling Skydrol® 500 B into the syringe, the liquid was spread by the needle and has moved by gravity, capillarity and diffusion into the paper tape. After deposition of a first amount (1-2 ml) the resistance grew until the range of 1 kOhm. After exposing the syringe a second time (about 1-2 milliliters) the resistance grew essentially sigmoidally to about 100 MOhm, being the limit of the instrument. The curve shown in the diagram ( FIG. 1 ) represents a kinetic process driven by the diffusion of Skydrol® 500 B into the acrylic matrix, i.e. when changing e.g. the mass of the sample, the initial liquid amount, exposed surface etc. the curve would change its kinetic parameters.
[0066] An important feature of this invention is the stability of the non-conducting state. Once, a relevant amount of liquid (1 milliliters) has entered the space between hydraulic tube area and paper tape, the sensor will absorb this liquid because the leaking liquid has to pass the position of the sensor. The absorbed liquid interrupts the electrical contact at a certain position. Drying of the sensor is extremely slow due to the low vapor pressure of Skydrol. It could be shown that the extraordinary high resistance will be maintained for many days. This means that the read-out of the sensor must not be done during flight operations, but it can be done by electronic devices that are not part of the operational electronics.
[0067] Some embodiments of the invention are set forth in claim format directly below:
[0068] 1) An aircraft with an improved landing or taking off security means, characterised in that the aircraft comprises a hydraulic liquid leakage monitor for detecting of aircraft hydraulic liquid leakage in situ from the aircraft hydraulic system whereby the aircraft hydraulic liquid conduit that is at least in part surrounded by a sensing means (sensing tape, sheet, fabric or coating) [ 2 ] that is permeable for aircraft hydraulic liquid (such as Skydrol® 500 B) and that is coated or is winded around the hydraulic tube [ 1 ] to be sensed for an hydraulic fluid escape and whereby the sensing means comprises or is impregnated with a sensing material that comprises a composite comprising at least two components. 1) particles or powder of an electrically-conductive material dispersed in 2) an matrix that is solvable to aircraft hydraulic fluid whereby the concentration, dispersity and/or orientation of the electrically-conductive particles are tailored to be in the proximity of the percolation threshold in a way that the composite itself is normally in the electrically-conductive state but has the percolation conductivity interrupted after entering of aircraft hydraulic fluid into the composite [ 2 ] and further comprising electrodes [ 4 ] for measuring resistance in sensing material [ 2 ].
[0069] 2) The aircraft with aircraft hydraulic liquid leakage monitor according to embodiment 1, wherein the conductivity of the sensing material is interrupted as consequence of the absorption of the aircraft hydraulic fluid into the matrix embedding the electrically-conductive material powder or particles by transition through the threshold of percolation conductivity (collapse of percolation conductivity, COPC) into the non-conductive state.
[0070] 3) The aircraft with aircraft hydraulic liquid leakage monitor according to any one of the embodiments 1 to 2 , whereby the aircraft hydraulic liquid leakage monitor comprises the sensing coating, tape, sheet or fabric [ 2 ] surrounding or winded around the hydraulic tube [ 1 ] such to capture into the sensing materials the leaked hydraulic liquids or part of the that are otherwise dispersed into an aerosol due to the high pressure difference between the outside and the inside of the hydraulic tube or conduit.
[0071] 4) The aircraft with aircraft hydraulic liquid leakage monitor according to any one of the embodiments 1 to 3, whereby there is a non conducting for aircraft hydraulic fluid permeable coating between the sensing tape, sheet, fabric or coating and the aircraft hydraulic liquid conduit so that the sensing tape, sheet, fabric or coating does in a non-leak condition is not in direct contact with the aircraft hydraulic liquid conduit, is isolated from or is not conductively connected to the hydraulic liquid conduit.
[0072] 5) The aircraft with aircraft hydraulic liquid leakage monitor according to any one of the previous embodiments, whereby the aircraft hydraulic liquid leakage monitor comprises a sensing tape, sheet, fabric or coating in the form of a strip or wire and so arranged around the aircraft hydraulic liquid conduit that at least one sensing strip or sensing wire is formed with slits between the sensing strip or sensing wire.
[0073] 6) The aircraft with aircraft hydraulic liquid leakage monitor according to any one of the previous embodiments 1 to 5, whereby the slit comprises the exposed non conductive material surrounding said the aircraft hydraulic liquid conduit.
[0074] 7) The aircraft with aircraft hydraulic liquid leakage monitor according to any one of the previous embodiments 1 to 5, whereby the slit comprises exposed surface of the aircraft hydraulic liquid conduit.
[0075] 8) The aircraft with aircraft hydraulic liquid leakage monitor according to any one of the previous embodiments, whereby the at least one sensing strip or sensing wire is being arranged as a coil of two or more turns and whereby the spirals or winds is contiguous with a space between or the sensing strip or sensing wire so arranged that each strip or wire from one elongated unit without contacts or interconnections between the spirals or winds.
[0076] 9) The aircraft with aircraft hydraulic liquid leakage monitor according to any one of the previous embodiments, whereby the at least one sensing strip or sensing wire helical engaged around said the aircraft hydraulic fluid conduit with a contiguous slit, groove or space between the spirals or winds of the helix.
[0077] 10) The aircraft with aircraft hydraulic liquid leakage monitor according to any one of the previous embodiments, whereby at a condition of leak the contiguous slit, groove or space for a hydraulic liquid flow.
[0078] 11) The aircraft with aircraft hydraulic liquid leakage monitor according to any one of the previous embodiments, whereby in a non leak condition the sensing strip or sensing wire is in an electrically-conductive state but when the hydraulic fluid penetrates in said the sensing strip or sensing wire this switches into the non-conductive state and a hydraulic fluid leak is monitored in said aircraft.
[0079] 12) The aircraft with aircraft hydraulic liquid leakage monitor according to any one of the previous embodiments, whereby in a non-leak condition the sensing strip or sensing wire is in an electrically-conductive state but when the hydraulic fluid attacks or destroys a zone in the sensing strip or sensing wire this switches into the non-conductive state and an hydraulic fluid leak is monitored in said aircraft.
[0080] 13) The aircraft with aircraft hydraulic liquid leakage monitor according to any one of the previous embodiments, whereby the sensing strip or sensing wire is a circular electrically conductive coil core around the aircraft hydraulic fluid conduit with said the slit between said each wining or spiral.
[0081] 14) The aircraft with aircraft hydraulic liquid leakage monitor according to any one of the previous embodiments, whereby the sensing strip is a mm strips and the slit is a mm slit.
[0082] 15) The aircraft with aircraft hydraulic liquid leakage monitor according to embodiment 14, whereby the mm strip has a broadness in the range of 1 mm to 100 mm and the slid has a broadness in the range of 1 mm to 100 mm and a length in the cm or meter range.
[0083] 16) The aircraft with aircraft hydraulic liquid leakage monitor according to embodiment 14, whereby the mm strip has a broadness in the range of 1 mm to 10 mm and the slit has a broadness in the range of 1 mm to 10 mm.
[0084] 17) The aircraft with aircraft hydraulic liquid leakage monitor according to any one of the previous embodiments 1 to 16, whereby the strip has a height in the pm range for instance 10 pm to 500 μm.
[0085] 18) The aircraft according to any one of the previous embodiments 1 to 16, whereby the slit has depth in the range in the pm range for instance in a range of a value between 10 μm and 500 μm.
[0086] 19) The aircraft with aircraft hydraulic liquid leakage monitor according to any one of the previous embodiments, whereby the hydraulic liquid leakage monitor is real-time.
[0087] 20) The aircraft with aircraft hydraulic liquid leakage monitor according to any one of the previous embodiments, whereby the matrix of the sensing tape, sheet, fabric or coating does not resist an attack by used aviation hydraulic fluid in the hydraulic aircraft system.
[0088] 21) The aircraft with aircraft hydraulic liquid leakage monitor according to any one of the previous embodiments, whereby the aircraft hydraulic liquid leakage monitor, wherein the conductive state of the matrix of the sensing tape, sheet, fabric or coating does not resist an attack by used aviation hydraulic fluid in the hydraulic aircraft system.
[0089] 22) The aircraft with aircraft hydraulic liquid leakage monitor according to any one of the previous embodiments 1 to 21, whereby the sensing tape, sheet, fabric or coating comprises a non porous matrix.
[0090] 23) The aircraft with aircraft hydraulic liquid leakage monitor according to any one of the previous embodiments 1 to 21, the sensing tape, sheet, fabric or coating comprises a not nano- micro- , meso- or macroporous.
[0091] 24) The aircraft with aircraft hydraulic liquid leakage monitor according to any one of the previous embodiments 1 to 21, the non conductive or isolating material between said the hydraulic fluid conduit and the sensing tape, sheet, fabric or coating is a non porous matrix.
[0092] 25) The aircraft with aircraft hydraulic liquid leakage monitor according to any one of the previous embodiments 1 to 21, the non conductive or isolating material between said the hydraulic fluid conduit and the sensing tape, sheet, fabric or coating is a non conductive or isolating material not nano- micro- , meso- or macroporous.
[0093] 26) The aircraft with aircraft hydraulic liquid leakage monitor according to any one of the previous embodiments 1 to 25, whereby the matrix of the sensing tape, sheet, fabric or coating does not resist an attack by or contact with aviation phosphate ester fluids.
[0094] 27) The aircraft with aircraft hydraulic liquid leakage monitor according to any one of the previous embodiments 1 to 25, whereby the matrix of the sensing tape, sheet, fabric or coating does not resist an attack by or contact with a phosphate-ester based aircraft hydraulic fluid.
[0095] 28) The aircraft with aircraft hydraulic liquid leakage monitor according to any one of the previous embodiments 1 to 25, whereby the matrix of the sensing tape, sheet, fabric or coating does not resist an attack by or contact with aircraft hydraulic fluids of the group consisting of BMS 3-11: Skydrol 500B-4, Skydrol LD-4, Skydrol 5 and Exxon HyJetIV-A plus.
[0096] 29) The aircraft with aircraft hydraulic liquid leakage monitor according to any one of the previous embodiments 1 to 25, whereby the matrix of the sensing tape, sheet, fabric or coating does not resist an attack by or contact with aircraft hydraulic fluid, Skydrol® 500 B.
[0097] 30) The aircraft with aircraft hydraulic liquid leakage monitor according to any one of the previous embodiments 1 to 29, whereby the conductive particles are of the group consisting metal particle, a particle coated by said metal, a carbon black particles or particles of conductive ceramics.
[0098] 31) The aircraft with aircraft hydraulic liquid leakage monitor according to any one of the previous embodiments 1 to 29, whereby the metal particle is nickel, cupper or silver or a particle coated with nickel, cupper or silver.
[0099] 32) The aircraft with aircraft hydraulic liquid leakage monitor according to any one of the previous embodiments 1 to 29, whereby the matrix of the sensing tape, sheet, fabric or coating is an acrylic resin.
[0100] 33) The aircraft with aircraft hydraulic liquid leakage monitor according to any one of the previous embodiments 1 to 29, whereby the acrylic resin comprises methyl methacrylate monomer (MMA) and or Polymethyl methacrylate (PMMA).
[0101] 34) The aircraft with aircraft hydraulic liquid leakage monitor according to any one of the previous embodiments 1 to 29, whereby the composite comprises nickel powder in acrylic matrix.
[0102] 35) The aircraft with aircraft hydraulic liquid leakage monitor according to any one of the previous embodiments 1 to 29, whereby after exposure to hydraulic liquid the resistance in the composite increases which can be displayed on a screen after processing in that the curve of resistance (Ohm) vs. time (min) shows an increase in the resistance.
[0103] 36) The aircraft with aircraft hydraulic liquid leakage monitor according to any one of the previous embodiments 1 to 29, whereby the integral length hydraulic tube has 10 m or more than 1 m.
[0104] 37) The aircraft with aircraft hydraulic liquid leakage monitor according to any one of the previous embodiments 1 to 29, whereby the diameter of tube has a diameter of 1 cm or more than 0.5 cm.
[0105] 38) The aircraft with aircraft hydraulic liquid leakage monitor according to any one of the previous embodiments 1 to 29, whereby the diameter of tube has a diameter of 1 between 0.7 and 1.2 cm.
[0106] 39) The aircraft with aircraft hydraulic liquid leakage monitor according to any one of the previous embodiments 1 to 29, whereby the with sensing material covered surface is about 0.30 m 2 .
[0107] 40) The aircraft with aircraft hydraulic liquid leakage monitor according to any one of the previous embodiments 1 to 29, whereby volume to add when layers have approx. 100 micron is between 25-35 cm 3 and preferably 29-31 cm 3 .
[0108] 41) The aircraft with aircraft hydraulic liquid leakage monitor according to any one of the previous embodiments 1 to 29, whereby the matrix of the sensing tape, sheet, fabric or coating is an acrylic resin with a density between 0.5 to 1.5 g/cm 3 , preferably between 0.8 and 1.2 g/cm 3 , more preferably 0.9 and 1.1 g/cm 3 and most preferably around 1 g/cm 3 .
[0109] 42) The aircraft with aircraft according to any one of the previous embodiments 1 to 29, comprising a controller based on a software assisted measurement system and control algorithm.
[0110] 43) The aircraft with aircraft hydraulic liquid leakage monitor of embodiment 42, whereby the controller has a computer readable medium tangibly embodying computer code executable on a processor.
[0111] 44) The aircraft with aircraft hydraulic liquid leakage monitor of embodiment 43, whereby the processor is connected to provide a control signal to an actuator configured to signal or alarm the hydraulic liquid leakage.
[0112] 45) The aircraft with aircraft hydraulic liquid leakage monitor of embodiment 43, whereby the processor is connected to provide a control signal to an actuator configured to alert pilot or third party.
[0113] 46) The aircraft with aircraft hydraulic liquid leakage monitor of embodiment 43, whereby the processor is connected to provide a control signal to an actuator configured to locate the aircraft hydraulic liquid leakage defect.
[0114] 47) The aircraft with aircraft hydraulic liquid leakage monitor according to any one of the embodiments 42 to 46, whereby the controller operates as safety fuse for leaking hydraulic liquids whereby of noise small conductance variations that occur during operations (temperature variations, aging of adhesives etc) is disregarded by the processor but whereby an essentially loss of conductivity noise is regarded as an aircraft hydraulic liquid leakage.
[0115] 48) The aircraft with aircraft hydraulic liquid leakage monitor according to any one of the embodiments 1 to 47, comprising a memory for storing the information signals and at least one transmitter for transmitting information signals to a base station adapted to receive information signals.
[0116] 49) The aircraft with aircraft hydraulic liquid leakage monitor of embodiment 48, characterized in that the base station is adapted to transmit interrogation signals.
[0117] 50) The aircraft with aircraft hydraulic liquid leakage monitor according to any one of the embodiments 42 to 49, whereby the at least one transmitters is formed by transponders which are adapted to receive the interrogation signals and to transmit information signals stored in the memory in response to receiving an interrogation signal.
[0118] 51) The aircraft with aircraft hydraulic liquid leakage monitor according to any one of the embodiments 42 to 49, characterized in that at least one transmitter or transponder is adapted to receive and transmit signals in the ether.
[0119] 52) The aircraft with aircraft hydraulic liquid leakage monitor according to any one of the embodiments 42 to 51, characterized in that at least the base station is adapted to receive and transmit signals via a telephone network.
[0120] 53) The aircraft with aircraft hydraulic liquid leakage monitor according to any one of the embodiments 42 to 51, characterized in that the transmitter or transponder is adapted for information communication via a mobile telephone network.
[0121] 54) The aircraft with aircraft hydraulic liquid leakage monitor according to any one of the previous embodiments, to enhance passenger's safety.
[0122] 55) The aircraft with aircraft hydraulic liquid leakage monitor according to any one of the previous embodiments, to detect presence of leaked hydraulic liquids at a very early stage.
[0123] 56) The aircraft with aircraft hydraulic liquid leakage monitor according to embodiment 55, whereby the matrix is highly solvable to aircraft hydraulic fluid.
BRIEF DESCRIPTION OF THE DRAWINGS
[0124] The present invention will become more fully understood from the detailed description given herein below and the accompanying drawings which are given by way of illustration only, and thus are not limitative of the present invention, and wherein:
[0125] FIG. 1 is a curve of resistance (Ohm) vs. time (min) showing the increase in the resistance of Ni/Acryl composite after exposing to SKYDROL 500, tested on conductive paper tape.
[0126] FIG. 2 is a curve of resistance (Ohm) vs. time (min) showing the increase in the resistance of Ni/Acryl composite after exposing to SKYDROL 500, tested using a breather-bleeder.
[0127] FIG. 3 is a curve of resistance (Ohm) vs. time (min) showing the increase in the resistance of Ni/Acryl composite after exposing to SKYDROL® 500 B, tested with real hydraulic tube and conductive paper tape.
[0128] FIG. 4 is a drawing that displays a possible set up for detecting hydraulic liquids, which comprises an hydraulic tube [ 1 ] , an isolating tape or coating [ 2 ] (permeable for hydraulic liquid, such as Skydrol® 500 B) after deposition impregnated with COPC based sensing coating (e.g. composite nickel powder in acrylic matrix, such as from Holland Shielding (Conductive nickel coating 3801), a winding direction for tape [ 3 ] (to prevent that the conducting COPC based sensing coating (comprising the conducting composite) makes a short-cut with the hydraulic tube during deposition and electrodes [ 4 ] for measuring the resistance (deposed in with flex in COPC based sensing coating).
[0129] FIG. 5 is a table with an overview of materials resistance to Attack by Aviation Phosphate Ester Fluids such as SKYDROL.
[0130] FIG. 6 [ 1 ] is an hydraulic tube or an hydraulic fluid guidance tube, [ 4 ] are the electric contacts for instance the electrodes for measuring the resistance, [ 2 ] is zone on the hydraulic tube which is covered by an isolating tape or coating on said the hydraulic tube or guidance tube which isolating or non conductive tape or coating is permeably for hydraulic fluid for instance for the hydraulic liquid, Skydrol® 500 B or an hydraulic fluid guidance tube. This zone is not covered by sensing material. [ 3 ] is the sensing area for instance a coating comprising composite nickel powder in acrylic matrix, such as from Holland Shielding (Conductive nickel coating 3801). This sensing area covers the isolating tape or non conductive coating for preventing in a non defaulting condition that it makes direct contact with said the hydraulic tubing and [ 5 ] demonstrates a potential exit hole for instance a pinhole crack emitting aerosols. | The present invention relates generally to a system that monitors the condition of hydraulic systems for an aircraft or for other applications and, more particularly, to a system and method for detecting leakage within the hydraulic system aboard an aircraft. Such system is detecting hydraulic liquids by extended sensors based on the collapse of percolation conductivity (COPC) which sensors are covering an area in the aircraft. | 1 |
FIELD OF THE INVENTION
The present invention relates to treatment of human or animal hair, and more particularly to the deodorization of such hair which contains residual thioglycolic acid compounds as a consequence of prior treatment to effect waving, straightening, softening and the like. Deodorization is effected by applying a composition containing a crystalline siliceous zeolitic molecular sieve material having a framework Si/Al 2 ratio of at least 18 and having an adsorptive capacity for water of not greater than 10 weight percent when measured at 25° C. and a water vapor pressure of 4.6 torr. Advantageously the molecular sieve-containing composition contains additional hair-conditioning materials.
BACKGROUND OF THE INVENTION
A considerable number of compositions have been proposed and are currently marketed for the purpose of modifying the configuration of hair shafts to achieve the appearance desired by hair styling. The modification, in the main, alters the hair shaft by disrupting the disulphide cross-linkages in the keratin fibers, thereby permitting normally wavy hair to be made less wavy or allowing normally straight hair to be reshaped into a waved or curled configuration. A number of particular chemical compounds have been employed, but by far the most commonly used compound is thioglycolic acid or the ammonium, sodium, calcium and potassium salts of thioglycolic acid. The compounds appear to reduce the disulfide cross-link to sulfhydryl groups which allows an easier reorientation of the keratin fibers of the hair shaft. Other thiols and mercaptans can accomplish the necessary cleavage of the disulfide cross-link, but in general are less suitable for the purpose.
Although effective in altering the chemical structure of the hair shaft, the aforementioned organic sulfur-containing compounds are characterized by a generally offensive odor. This is particularly true of the thioglycolic acid compounds. While the odor is tolerable over the relatively short period of the hair treatment, it is extremely difficult to remove these sulfur-containing compounds from the hair and scalp following the treatment to a level where the odor is not detectable.
The common method for overcoming the residual odor problem is to apply a masking fragrance to the hair during and/or after the treatment. Such fragrances must, of necessity, be rather strong, and for that reason can also be objectionable to some people. In U.S. Pat. No. 4,738,841, issued Apr. 19, 1988, to V. P. Pigiet, another means is proposed for reducing the objectionable odor of thioglycolic acid compounds during hair treatment. This means comprises decreasing the amount of thioglycolic acid required by incorporating a thioredoxin or similar dithiol peptide into the treating composition which acts synergistically with a thioglycolic acid compound to disrupt the disulfide bond of hair keratin. This technique doubtlessly decreases the odor level during the hair treatment, but has less effect in lowering the post-treatment level of residual thioglycolic acid compound.
SUMMARY OF THE INVENTION
The present invention provides compositions comprising highly-siliceous zeolitic molecular sieve crystals which when applied in appropriate amounts to hair containing malodorous sulfur-containing compounds effectively reduces the undesirable odor to levels below the detection threshold of the human sense of smell. Advantageously the zeolitic molecular sieve has at least about 90 percent of its framework structure composed of SiO 2 tetrahedral oxide units, has pore diameters of at least about 5.5 Angstroms and a capacity for adsorbed water of not greater than 10 weight percent when measured at 25° C. and at a water vapor pressure of 4.6 torr. The compositions can consist of the zeolite crystals or be combined in a powderous mixture with other ingredients which facilitate application or provide additional conditioning or grooming benefits to the hair, or in a flowable liquid-based composition such as a cream or mousse. The invention also includes the deodorization process utilizing the aforementioned compositions.
DETAILED DESCRIPTION OF THE INVENTION
The molecular sieves suitably employed in the compositions of the present invention include any of the crystalline aluminosilicate molecular sieves well known in the art in which at least about 90, and preferably at least 95, percent of the framework tetrahedral oxide units are SiO 2 tetrahedra and which have a sorptive capacity for water at 25° C. and 4.6 torr of less than about 10 weight percent, preferably less than about 6 weight percent. In the case of aluminosilicate molecular sieves, the framework SiO 2 /Al 2 O 3 molar ratio is at least 18 and is preferably at least 35. Molecular sieve zeolites having framework molar Si/Al 2 ratios of from 200 to 500 are particularly suitable. Many of the synthetic zeolites prepared using organic templating agents are readily produced in a highly siliceous form. In many instances the reaction mixtures can be especially free of aluminum-containing reagents. These zeolites are markedly organophilic and include ZSM-5 (U.S. Pat. No. 3,702,886); ZSM-11 (U.S. Pat. No. 3,709,979); ZSM-35 (U.S. Pat. No. 4,016,235); ZSM-23 (U.S. Pat. No. 4,076,842); and ZSM-38 (U.S. Pat. No. 4,046,859) to name only a few. It has been found that the silica molecular sieves known as silicalite and F-silicalite are particularly suitable for use in the present invention and are thus preferred. These materials are disclosed in U.S. Pat. Nos. 4,061,724 and 4,073,865, respectively. To the extent the aforesaid siliceous sieves are synthesized to have SiO 2 /Al 2 O 3 ratios greater than 35, they are frequently suitable for use in the present compositions without any additional treatment to increase their degree of hydrophobicity. Molecular sieves which cannot be directly synthesized to have both sufficiently high Si/Al ratios and/or degree of hydrophobicity can be subjected to dealumination techniques, fluorine treatments and the like, which result in organophilic zeolite products. High-temperature steaming procedures for treating zeolite Y which result in hydrophobic product forms are reported by P. K. Maher et al, "Molecular Sieve Zeolites," Advan. Chem. Ser. 101, American Chemical Society, Washington, D. C., 1971, p. 266. A more recently reported procedure applicable to zeolite species generally involves dealumination and the substitution of silicon into the dealuminated lattice site. This process is disclosed in U.S. Pat No. 4,503,023, issued Mar. 5, 1985, to Skeels et al. Halogen or halide compound treatments for zeolites to increase their hydrophobicity are disclosed in U.S. Pat. Nos. 4,569,833 and 4,297,335.
In the case of the aluminosilicates or silica polymorphs produced using large organic templating ions such as tetraalkylammonium ions, it is frequently necessary to remove charge balancing organic ions and any occluded templating material in order to permit their use in adsorption processes.
It should be pointed out that with respect to the hydrophobic aluminosilicates it is the framework SiO 2 Al 2 O 3 ratio which is important. This is not necessarily the same ratio as would be indicated by conventional wet chemical analysis. Especially is this the case when dealumination has been accomplished by high temperature steaming treatments wherein aluminum-containing tetrahedral units of the zeolite are destroyed, but the aluminum values remain, at least in part, in the zeolite crystals. For such zeolite products resort must be had to other analytical methods such as X-ray and NMR. One such steam-treated zeolite Y composition, known in the art as LZ-10, has been found to be particularly useful in the compositions of the present process, especially when utilized in combination with the silica polymorph silicalite. The process for preparing LZ-10 is described in detail in U.S. Pat. No. 4,331,694. When applied to the sequestration of odors due to organic sulfur-containing compounds such as thioglycolic acid, a benefit appears to be obtained by such a combination of molecular sieves in all proportions, but each type of adsorbent is preferably present in an amount of at least 10 percent based on the total weight of the two adsorbents (hydrated weight basis).
As synthesized the molecular sieve particles have, in general, sizes of about 0.5 to about 6.0 micrometers. The particles are most frequently agglomerates having sizes in the range of 10 to about 20 micrometers. Molecular sieve particles in this range, i.e., 0.5 to 20 micrometers or even larger, are all suitably utilized in forming the present compositions. It is preferred, however, that the particles are within the size range of 1.5 to 6.0 micrometers.
The molecular sieve particles can be topically applied to the hair and scalp being treated to remove the odor of the sulfur-containing compound or compounds in its undiluted and powderous form. Since, however, the molecular sieve is highly effective for the intended purpose, uniform application of sufficient quantities to deodorize the area is facilitated by incorporating the molecular sieve crystals in a composition containing inert diluents, liquid dispersion media or conventional substances used to condition hair.
If it is desired to employ a dry powderous composition, the molecular sieve can be admixed with such diluent/agglomerating agents as starch, silica powders, grain flours, wood flour, talc, pumice, clays, calcium phosphates and the like. Usually the molecular sieve constitutes from about 1 to about 10 weight percent of the overall mixture.
It is particularly preferred that the molecular sieve be dispersed in a liquid, advantageously aqueous, medium, and applied to the hair as a gel, cream, lotion, mousse and the like. These compositions can comprise water as the major constituent and suspension medium into which the molecular sieve particles are suspended by means of suspension aids. Such suspension agents include hydrophilic colloidal dispersions of clays and those polyelectrolytes which function primarily to lower the zeta potential of the dispersed phase and thus lessen the tendency of the molecular sieve particles to agglomerate, and viscosity enhancers such as hydroxyethyl cellulose and carboxypolymethylene, available commercially under the trademarks Natrosol 250MR (Aqualon Company) and Carbopol 941 (B. F. Goodrich Company), respectively.
Especially useful as dispersion or suspension agents are the colloidal magnesium aluminum silicate clays such as those commercially available under the trademarks Laponite (LaPorte PLC, Waverly Mineral Prod. Co.) and Veegum (R. T. Vanderbilt Company). The colloidal magnesium silicates are refined from the natural minerals commonly referred to as smectite, montmorillonite, hectorite or macaloid clays. These clay minerals have a sodium magnesium-fluoro-litho-silicate structure and are characterized by an expanding lattice structure which swells when heated and dispersed in water. The magnesium, lithium and fluorine are inaccessibly located within the lattice structure and are, therefore, not water soluble or exchangeable. Laponite is a synthetic magnesium silicate, having properties similar to natural smectites. This synthetic silicate contains exchangeable lithium and calcium cations in place of the aluminum present in natural smectite clays. As used herein, these clays, both synthetic and naturally occurring, are identified by the term magnesium silicates of the smectite type or, alternatively, as magnesium silicates having the smectite structure.
Other commercially available polyelectrolyte suspension aids, which are somewhat less effective in lowering the zeta potential of aqueous suspensions of high-silica zeolites than the aforementioned smectite clays, include a copolymer of sodium acrylate and acrylamide (available commercially from Allied Colloids Company under the trademark Percol 726 and Percol 727); the sodium salt of a polymerized naphthalene sulfonic acid and the sodium salt of a polymerized alkyl naphthalene sulfonic acid (both available commercially under the trademarks Darvan No. 1 and Darvan No. 9, respectively, from R. T. Vanderbilt Company); a penta sodium salt of aminotri(methylene phosphonic acid) sold commercially by Monsanto Chemical Company under the trademark Dequest 2006; and the sodium salt of a polymeric carboxylic acid, a polyelectrolyte with an anionic charge similar to Dequest 2006, sold by Allied Colloid Company under the trademark Dispex N-40. These other polyelectrolytes are generally not effective over long periods of time and are preferably employed in combination with viscosity enhancing agents to counteract the effects of Stokes Law
Further, non-surfactant type hydrophilic colloids that coat the molecular sieve particles can also be employed, but they are, in general, not entirely effective to prevent settling of the zeolite particles in aqueous trademark of GAF Chemical Company) and Resyn 28-1310 and Resyn 28-2930, both trademarks of National Starch Company. Gantrez AN is a copolymer of vinyl ether and maleic anhydride. It is a water-soluble polymeric anhydride that slowly hydrolizes in the presence of water to form the free acid. Addition of small quantities of alkali aids solution, but must be controlled since it results in dramatic increase in viscosity of the dispersed aqueous phase. PVM/MA copolymer acts as a protective colloid by adsorbing onto the surface of solids that are to be dispersed and suspended. It is available in several molecular weight ranges. The grades 119 and 169 reflect molecular weights ranging from 20,000 to 67,000. Resyn 280-1310 is a carboxylated vinyl acetate copolymer which must be neutralized from ethanol solutions to achieve water solubility. When neutralized with an amino hydroxy compound such as AMP (2-amino-2-methyl-1-propanol), water solubility occurs. Coating suspended particles in hydroalcoholic vehicles with the neutralized Resyn can prevent coalescence of solid particles by the process of adsorption. The Resyn in this case acts as a protective colloid to prevent contact with other solid particles. Resyn 28-2930 is a terpolymer of vinylacetate, crotonic acid and neo-decanoate. As with Resyn 28-1310, ethanol solutions of this polymer must be neutralized with AMP to achieve water solubility.
Anionic polyelectrolytes such as CMC are advantageously employed in combination with the colloidal magnesium aluminum silicates described above for suspending high-silica zeolites in aqueous media. CMC, an alkali metal salt of the carboxymethylether of cellulose, is an anionic water-soluble polymer derived from cellulose by the reaction of alkali metal chloracetate with alkali cellulose. It is classified as an anionic polyelectrolyte and is commercially available predominantly as the sodium salt. The properties of CMC can vary considerably, the principal determinants being the degree of substitution (DS) and the degree of polymerization (DP) or chain length. The DS is defined as the average number of carboxymethyl groups introduced, i.e., substituted for hydroxyl groups per anhydroglucose unit in the cellulose. The DP is determined by the chain length of the starting cellulose which can be as high as 5000. The DP is reflected in the viscosity of the CMC solution and as the DP increases the viscosity increases. CMC is commercially available in viscosities from about 3000 cP in 1% solution to 17 cP in 2% solution, corresponding to a DP range of from about 1000 to 200.
In addition to the aforesaid constituents of the vehicle in the present compositions, a number of other materials can be added to provide cosmetic and/or formulation functionality. These include propylene glycol, hexylene glycol and 1,3-butylene glycol, all of which serve to act as rheological modifiers. Colorants and pigments are suitably incorporated into the present compositions, as are fragrances which are compatible with, i.e., not eliminated by the activity of, the high-silica zeolites also present. Lower alcohols such as ethanol and they do not cause precipitation of the CMC constituent, if it is present. Fungicides, bactericides and medicinal or therapeutic materials can also be present. When antimicrobial or preservative agents are included in the compositions, it should be noted that not all such agents are compatible with the high-silica zeolite constituent. It is believed that this incompatibility, i.e., ineffectiveness, is due, at least in part, to these substances being adsorbed into the internal pore system of the zeolite crystals and are thus limited in their contact with microorganisms present in the medium outside the zeolite particles. Accordingly, it is preferred to utilize as the biocidally active component a phenoxarsine-containing compound, preferably one that is soluble at least to a moderate extent in the glycol or aqueous media of the composition. Such compounds are well known in the art and include 10-chlorophenoxarsine; 10-bromophenoxarsine; 10-phenoxarsinyltrichloracetate; (10-phenylarsinyl)-n-octylxanthate; 10-methylphenoxarsine; 10-butylphenoxarsine; 10-phenylphenyloxarsine; (10-phenoxarsinyl) diisopropylphosphonate; and 10,10'-oxybisphenoxarsine. A particularly preferred phenoxarsine compound for use in the present compositions is cis-1-(3-chloro-2-propanyl) - 3,5,7 - triaza-1-azoniatricyclo (3.3.1.1[3,7]) decane halide, particularly the chloride or bromide, available commercially under the trade name Dowicil 200, or as quaternium-15.
A number of compositions suitable for use in the practice of the present invention are exemplified by those prepared in the following Examples.
EXAMPLE 1
The ingredients listed below, and in the proportions indicated, were combined to form a composition effectively used in the practice of the present invention.
______________________________________ Wt. %______________________________________Laponite XLS 1.00Laponite XLG 0.50Distilled Water 84.35Zeolite* 5.00Stepanate SXS 4.00Propylene Glycol 5.00Dowicil 200 0.10Disodium EDTA 0.05 100.00______________________________________ *Equal parts by weight of zeolite LZ10 and silicalite.
The composition was prepared by dispersing at room temperature the Laponite XLS and the Laponite XLG in distilled water using a high shear propeller mixer for a period of about 20 minutes. The zeolite particles were added and mixed under low shear conditions for about one hour, and then were added the propylene glycol and the Stepanate SXS (a sodium xylene sulfonate which acts as a hydrotrope coupling agent) and the mixing continued until the mixture was uniformly blended. Lastly, the Dowicil 200 and the disodium salt of ethylenediamine tetracetic acid (EDTA) were added and mixing continued for an additional 15 minutes. The formulation was dispensable as a mousse from an aerosol dispenser containing 81 percent by weight of the aforesaid formulation and 19 percent by weight isobutane propellant.
EXAMPLE 2
Using the same zeolite constituent as in Example 1, the following formulation was prepared by mixing together at room temperature the ingredients listed below and in the order in which they are listed.
______________________________________ Wt. %______________________________________Distilled Water 93.85Mackalene 316 2.00Merquat S 2.00Zeolite 2.00Dowicil 200 0.10Disodium EDTA 0.05 100.00______________________________________
In the formulation, the Mackalene 316 is a commercially available surfactant which serves to condition the hair having an advantage over some other cationic surfactants in that it rinses more readily from the hair and thereby prevents build-up, and the Merquat S, also commercially available, is a polyquaternium-7 high molecular weight cationic dimethyldiallyl ammonium chloride compound which contributes excellent lubricity, wet compatibility and luster to hair without build-up. This formulation is also dispensable as a mousse from an aerosol system using isobutane as the propellant.
EXAMPLE 3
(a) A base slurry was prepared by swelling 1.86 parts by weight Veegum in 89.9 parts by weight distilled water at a temperature of 65°-70° C. To this colloidal silicate system was added with mixing 0.93 parts by weight of sodium carboxymethyl cellulose (CMC 7LF). The mixing was continued for one hour and then the mixture was allowed to cool. When the temperature reached 50° C., 7.05 parts by weight hexylene glycol was added and the resulting composition mixed for 15 minutes. Finally 0.21 parts by weight Dowicil 200 and 0.05 parts by weight disodium EDTA were added and completely dispersed over the period of about 15 minutes.
(b) A zeolite-containing slurry was formed by the high shear mixing of 1.00 parts by weight Laponite XLS and 0.50 parts by weight Laponite XLG in 79.5 parts by weight distilled water for the period of about 20 minutes. Thereafter 5.0 parts by weight of the same zeolite constituent as employed in Example 1, above, was incorporated by low shear mixing for one hour and then an additional 5.0 parts by weight of the same zeolite was similarly incorporated. Thereafter 4.0 parts by weight Stepanate SXS and 5.0 parts by weight of propylene glycol were added and thoroughly blended into the composition.
(c) Equal parts by weight of the compositions of parts (a) and (b) were combined and 81 parts by weight were placed in an aerosol dispenser with 19 parts by weight isobutane. The mixture is found to be highly effective to remove from human hair the odor resulting from residual thioglycolic acid after a permanent wave treatment. | Treatment of human or animal hair for purposes of waving, straightening or softening using compositions containing thioglycolic acid compounds commonly leave an undesirable odor due to the presence of residual trace amounts of the thio compound. The compositions of the present invention contain siliceous crystalline molecular sieves either as the sole active ingredient or in combination with hair conditioners. When applied to hair containing conventional, acid or soft wave hair perming solutions, the molecular sieve constituent effectively adsorbs and holds the residual odor-causing thioglycolic acid compound so that its odor is reduced to below its olfactory detection level threshold. | 0 |
TECHNICAL FIELD
This invention relates to methods and apparatus employing a common mechanical drive source to operate a plurality of machine elements including a reciprocally moving carriage or the like, wherein the carriage dynamically reverses its movement direction. More particularly, the present invention relates to xerographic copier/duplicators having a main drive motor that is selectively coupled so that copy sheet paper processing elements function concurrently with the reciprocal motion of a carriage mechanism. The present invention is particularly well suited for use in small, low cost, xerographic copier/duplicators that employ photoconductor drums or belts which receive, develop and transfer original document images to copy sheets. Although not necessarily limited thereto, the present invention is particularly useful for copiers with carriage that hold the original document to be copied and move it past a scan window.
BACKGROUND ART
Xerographic type copiers using reciprocally movable carriages to provide scanning of a document or thing to be copied have been known for many years. Typically, these carriages have either held the optics such as lenses and mirrors which are moved so as to scan a fixed document, or have retained the document itself so as to move it past a fixed scan window and optic coupler. U.S. Pat. No. 2,959,095 is an example of the latter type of scanning system.
It is generally preferred, especially for low cost copiers, that the drive motor concurrently operates as many of the machine elements as possible. Frequently such systems employ mechanical and/or electromechanical switching elements that rapidly reverse the direction of traverse of the carriage. For low speed or table-top copiers, simple switching devices are preferred for this function because they minimize both cost and carriage reversal time. Unfortunately, such devices also cause brief deviations of power application to the other copier components because of the carriage inertia. This is not overly detrimental for systems wherein the image is directly transferred from the original document onto a photosensitive copy sheet, since image transfer is complete before carriage reversal occurs.
However, the result is different for systems using photoconductive belts or drums to receive the image which is carried for some distance from the imaging station (usually including some intermediary operation such as development) to the point of transfer to a copy sheet. Such systems frequently produce a short band of blurred copy on the copy sheet because the transfer function is still in progress at the time of carriage motion reversal unless the carriage scan motion is carried out excessively or the distance from image to transfer stations is made long enough so that transfer has not started at the time of carriage reversal. The two latter-mentioned options are unacceptable, particularly for compact, low cost copiers.
The only arrangement known in the prior art for decoupling the adverse effects of the reciprocating carriage motion reversal from the remainder of the machine operation is shown in U.S. Pat. No. 3,697,165 by Morriston et al. where the carriage is driven by a slotted link and link pin connected to follow motion of a closed loop chain. Separate switches at the 90° turns on each end of the chain reverse the drive motor coupling to the chain. This configuration is intended to cause direction reversal of the carriage at approximately the zero horizontal motion point of the yoke and link pin. Such a system requires acceptance of a substantial cost penalty for the additional parts, switches and circuitry.
Various shock absorbing mechanical couplers have also been known in the past, Lewis et al. U.S. Pat. No. 2,071,885 being one example. Lewis et al. shows retained springs to provide mechanical coupling between radial ears of driving and driven hubs. Despite the presence of such couplers in the prior art and the continued presence of the copier quality degradation problem stemming from carriage motion reversal, the prior art is devoid of any suggestion that the problem is resolvable through a combination in accordance with the present invention as described below.
DISCLOSURE OF THE INVENTION
The present invention is concerned with a copier/duplicator that has a plurality of moving, xerographic process-related elements. These moving elements include a photoconductively surfaced means, an image developing means and a copy sheet conveyor for transferring and thereafter fixing the image from the photoconductive surface onto copy sheets. A power source is connected to operate at least the conveyor. A carriage is movably mounted for reciprocating motion for scanning original documents, books or things to transfer the image to the photoconductive surface. An interconnecting means joins the power source to the carriage movable mount and is selectively operable for causing the carriage to move in a reciprocal motion sequence. This interconnecting means includes means establishing a relatively rigid mechanical coupler from power source to carriage mounting means when the carriage moves in one direction, whereas other means provides a force absorbing, resilient coupling when the carriage is being moved in the opposite direction.
The interconnecting means can advantageously take the form of coaxially mounted collars, one of which has a groove for retaining a compressibly resilient component with the other collar having a shoulder extending radially into that groove. Another feature of the interconnecting means is that the shoulder and groove can have mating faces sloped tangentially relative to the inner collar thereby forming a solid interface for one direction of carriage movement.
The foregoing and other objects, features, advantages and applications of the present invention will be readily apparent to those having normal skill in the art from the following, more detailed description of the exemplary preferred embodiments as illustrated in the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a view showing the various elements of a typical xerographic copier/duplicator.
FIG. 2 is a rear view of the FIG. 1 copier/duplicator showing the mechanical coupling from a common power source motor to the xerographic elements.
FIG. 3 is an isometric view of the bidirectional power drive arrangement for the reciprocating carriage of the FIG. 1 copier/duplicator.
FIG. 4 is a plan view of the carriage drive shock absorbing coupler.
FIG. 5 is an exploded view of the FIG. 4 coupler.
FIG. 6 is a diagrammatic view of another bidirectional carriage drive arrangement using the FIGS. 4 and 5 coupler.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The copier 10 of FIG. 1 electrostatically or xerographically copies original documents placed on a transparent platen on reciprocably movable carriage 11 under cover 12. The document is illuminated in a line by lamp 15 at the scan window location 16 so that the light image of the document as it moves past scan window 16 is transferred through mirror 17, lens 18 and second mirror 19. Ultimately the image is transferred to photoconductive surfaced drum 20.
Drum 20 is initially electrostatically charged by a corona 22. After the original document image has been transferred to drum 20, this image is developed by developer 24. Copy sheets stored in supply cassette 25 are selectively picked by picker roller 26 and driven into the conveyor feed path including guides 28, synchronization rollers 30, transfer/detach corona 31, vacuum belt transport 32, fuser rollers 35 and output drive rollers 36 onto exit tray 38. Finally, a toner cleaning and recirculating device 39 and a discharge lamp 40 complete the elements arrayed around drum 20. Also a fuser oil wicking device is shown generally at 41. All of the foregoing elements operate in a generally conventional manner.
FIG. 2 is a rear view of the FIG. 1 copier and generally illustrates the interconnections from a main drive motor 44 to the various elements associated with the xerographic process which require motivation. As is frequently the case for relatively low cost copiers, main drive motor 44 is coupled so as to power as many elements as possible. Thus motor 44 is connected to sprocket 45 by means of a chain or belt 46 with the rotary power from sprocket 45 selectively driving the rollers of fuser 35 (FIG. 1).
Note that sprocket or gear 45 is likewise coupled to a secondary gear 47 which is connected by means of belt 48 to a drive cable 49 and then to pulleys 50 and 51, as well as to a direct drive pulley 52. Cable 49 wraps around pulley 52 and is attached to one end of reciprocably movable carriage 11 as at post 53, whereas spring 54 connects cable 49 to post 55 at the opposite end. That is, cable 49 is attached to post 55 via spring 54 at one end, sequentially passes around pulleys 52, 50 and 51 (in that order), then returns past pulley 50 to wrap around pulley 52 and is then attached to post 53. This arrangement selectively drives carriage 11 through a reciprocation motion as will be described in greater detail later. Gear 47 is also coupled by belt 56 to a gear or pulley 57 for the purpose of driving drum 20. In this particular configuration, a separate drive motor is employed for the magnetic roller of the developer 24, and this second motor is not shown in FIG. 2.
The rotary mechanical drive output of motor 44 is coupled by belt 58 to gears 59 and 60 to drive exit rollers 36 while belt 46 also drives fuser oil wicking mechanism 41 by gear 69. Gear 60 further drives belt 61 which is connected to the vacuum belt drive by means of gear 62 and to the synchronization rollers 30 through gear 63. By other roller connections, the drive for picker rollers 26 is energized as by one of gears 64-67, while an emitter is coupled to gear 68.
FIG. 3 shows the general configuration for selectively driving the carriage in its reciprocating motion. Common drive belt 48 is coupled to either the forward scan or initial motion drive pulley 51 as by spring clutch 70, or to reverse scan pulley 50 by spring clutch 71. Solenoid 75 controls pawl 76 to perform this operation, as will be described below.
Pawl 76 pivots around shaft 78. With solenoid 75 actuated, pawl 76 is pulled inwardly toward solenoid 75 so that stub 80 engages gear 81. This causes the spring clutch 70 to actuate, as is well known, and couple rotary motion from main drive belt 48 to the scan pulley 51. Thus, cable 49 is driven around pulleys 50-52 so that carriage 11 is pulled by cable 49 so as to move in an initial scan direction, to the right in FIG. 1.
At the end of the scan, means not shown (e.g. an appropriately located mechanical switch, microprocessor timing, etc.) causes scan solenoid 75 to be released. As a result, the lower extension 85 of pawl 76 engages gear 86 causing spring clutch 71 to operate, thereby imparting reverse direction rotary motion to pulley 50. This reverse direction rotary motion is realized through the coupling of gears 87 and 88.
The carriage 11 then returns to its original home position with the initial reversing shock being absorbed through the mechanism incorporated into pulley 50, as will be described later. Once the carriage has reached its home position, nub 89 on pawl 76 enters a detent (not shown) and thus releases gear 86, and a full cycle of the drive to the carriage is completed.
FIG. 4 illustrates the carriage return pulley 50, and FIG. 5 is an exploded view of the parts thereof. The spring clutch drive shaft 83 is firmly attached to inner collar 90 which is coaxially mounted within outer collar 91. Outer collar 91 has an inwardly facing groove 92 in which a spring element 94 is retained between the end face 95 of shoulder 96 for inner collar 90 and end wall 98 of groove 92.
The elements are held together by a washer 99 suitably attached but only shown in FIG. 5. Shoulder 96 has a tangentially angled face 100 relative to the peripheral surface of collar 90 with face 100 engaging a similarly sloped face 101 on the opposite end of groove 92 in collar 91. This provides a solid, strong driving interface when the pulley 50 is rotating in the scan direction for carriage 11. Conversely, when the solenoid 75 is released, selection of gear 86 and thus spring clutch 71 occurs substantially instantaneously so that spring 94 is compressed thereby absorbing the reversal of motion and providing a relatively smooth deceleration and reverse direction acceleration of the carriage. Thus, the shock of carriage direction movement reversal is isolated from the other elements in the copier. That is, in a typical compact copier operation, the transfer of the image from drum 20 to a copy sheet would not normally be completed at a point in time when the movement direction for carriage 11 is reversed. The blurring effect caused by the shock upon the various couplings into the main drive motor 44 is absorbed by spring 94 and pulley 50 as described above. Thus, the shock is absorbed in a manner which is effective to remove the blurring problem while allowing maximum overall machine operating speed through attainment of the most immediate reversal of reciprocation for carriage 11. Further, these advantages are realized in a relatively low cost manner as compared to the previously known devices.
FIG. 6 illustrates another implementation, in general form, wherein a single shock absorbing pulley 105 completely controls the reciprocable motion of a document carriage 106. Main drive motor 110 is connected to a drive belt 111 which passes around idler pulley 112 and then around pulleys attached to shafts 120 and 121 which selectively drive gears 115 and 116. Belt 111 reverses as it goes over the pulleys for drive shafts 120 and 121. Clutch mechanisms 122 and 123 which can be electromagnetic clutches, spring clutches or the like, interconnect drive shafts 120 and 121 into gears 115 and 116, respectively. Thus selection of clutching mechanism 123 couples power from belt 111 and shaft 121 into gear 116 and thus into gear 118. This causes the shock absorber pulley 105 to move in the direction of its solid coupling and to cause carriage 106 to scan to the right. Ultimately, clutch mechanism 123 is deactuated and clutch 122 is selected. Thus, gear 118 for pulley 105 now rotates in the opposite or home direction and pulley 105 provides shock absorber operation so as to decouple main drive motor 110 from its other mechanical components (not shown in FIG. 6).
Note that gear 115 is of a larger diameter than gear 116, thereby providing a faster return stroke for carriage 106 and thus reducing machine operating time per copy. Also note that the shock absorbing elements and drive shoulders of the pulley 105 are essentially in reversed orientation from that illustrated in FIGS. 4 and 5.
Although the present invention has been described with specificity as to the foregoing detailed description of the preferred embodiments, various changes, modifications, additions and applications other than those specifically mentioned herein will be readily apparent to those having normal skill in the art without departing from the spirit of this invention. | A bidirectional mechanical power coupler between power input and output means provides a firm connection in one direction and a resilient coupling in the opposite direction, particularly operable immediately after a rapid reversal of the mechanical drive direction. The coupler interconnects a common power source in a copier/duplicator with a reciprocating carriage for original document scanning. It is preferably implemented with a single pulley of coaxial hubs with an interposing arm extending from one hub into a spring-retaining groove in another hub. | 6 |
INCORPORATION BY REFERENCE
[0001] The entire disclosure of Japanese Patent Applications Nos. 2000-289889 filed on Sept. 25, 2000, 2001-100989 filed on Mar. 30, 2001 and 2001-280095 filed on Sep. 14, 2001 including specification, drawings and abstract is herein by reference in its entirety.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The invention relates to a hydraulic bearing device that supports a rotating shaft or the like.
[0004] 2. Description of the Related Art
[0005] [0005]FIG. 1 shows three partially developments of inner surfaces of bearing metals which constitute radial hydraulic bearing devices according to the related arts. Plural hydrostatic pockets 1 , 2 that are quadrilateral grooves such as shown by FIGS. 1 (A) and 1 (C) or U-shaped grooves such as shown by FIG. 1(B) are formed on inner surface of the bearing metals along a rotational direction of a rotating shaft. An oil-supplying hole 3 is formed in each hydrostatic pocket. Inner surface of the bearing metal except the hydrostatic pockets are land portions 4 for generating hydrodynamic pressure. FIG. 2 shows three plane views of bearing metals which constitute thrust hydraulic bearing devices according to the related arts. A hydrostatic pocket 5 that is a ring shape groove such as shown by FIG. 2 (A) or plural hydrostatic pockets 6 that are partially ring-shape grooves such as shown by FIGS. 2 (B) and 2 (C) are formed on a surface of the bearing metals. Plural oil-supplying holes 3 are formed in the ring shape hydrostatic pocket 5 , and a oil-supplying hole 3 is formed in the each partly ring shape hydrostatic pocket 6 . The surface of the bearing metal except the hydrostatic pockets 5 , 6 are land portions 4 for generating hydrodynamic pressure. Here, hydraulic bearing devices are distinguished two types that are a separated type such as shown by FIG. 1 (C) or FIG. 2(C), and a non-separated type such as shown by FIGS. 1 (A), 1 (B) or FIGS. 2 (A), 2 (B) according to a shape of the land portion 4 . The land portion 4 of the non-separated type is continuously all around of the surface of the bearing metal. On the other hand, the land portions 4 of the separated type are separated to rotational direction by drain grooves 7 that are formed between each hydrostatic pocket. At aforementioned hydraulic bearings, when pressure adjusted lubricant oil is supplied to the hydrostatic pockets 1 , 2 , 5 , 6 through the oil-supplying hole 3 , the hydraulic bearing functions as a hydrostatic bearing by filled lubricant oil between the hydrostatic pockets 1 , 2 , 5 , 6 of the bearing metal and an outer surface of a rotating shaft. Simultaneously, since the lubricant oil is filled between the land portion 4 and the rotating shaft, when the rotating shaft is rotated for the bearing metal, the hydraulic bearing functions as a hydrodynamic bearing by wedge effect that is generated between the land portions 4 and the outer surface of the rotating shaft.
[0006] Then, at the non-separated type bearing, especially in a case of U-shaped hydrostatic pockets 2 such as shown by FIG. 1(B), since area of the land portion 4 is large and continuously, a large amount of hydrodynamic pressure is generated. Therefore, the non-separated type bearing is effective in high rigidity and high damping effect. However, in a case of high rotating speed, a great heat due to fluid friction is generated at the land portion 4 . The great heat causes thermal expansion of the bearing metal, and a clearance between the bearing metal and the rotating shaft decreases. As the result, calorific value by fluid friction increases, and thermal expansion of the bearing metal increases. This is in a vicious circle that causes to deteriorate the performance of the bearing.
[0007] On the other hand, at the separated type bearing, heat generating at the land portion 4 is restrained because it is easy to be drained the lubricant oil by existence of the drain grooves 7 . However, existence of the drain grooves 7 causes deterioration of the rigidity because the land portion 4 is separated and small. Moreover, the separated type bearing tends to cause cavitation.
SUMMARY OF THE INVENTION
[0008] It is an object of the present invention to provide an improved hydraulic bearing device.
[0009] A hydraulic bearing device that supports a rotating shaft comprises a bearing metal. On a surface of the bearing metal, a hydrostatic pocket and a land portion are formed. The land portion is defined by the hydrostatic pocket and generates hydrodynamic pressure. The hydraulic bearing device further comprises a pressure fluid supplying source and an oil-supplying hole. The oil-supplying hole is opened in the hydrostatic pocket and provides pressure fluid from the pressure fluid supplying source to the hydrostatic pocket. On the land portion, a drain hole that drains the fluid is formed.
[0010] Because the hydraulic bearing device is provided with the hydrostatic pocket and the land portion, it functions not only as a hydrostatic bearing but also as a hydrodynamic bearing. Then, since the fluid is drained through the drain hole, thermal expansion of the bearing metal due to heat generation of the fluid is restrained. Moreover, since the drain hole does not separate the land portion, deterioration of bearing rigidity is restrained.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] Further objects, features and advantages of the present invention will become apparent from the following description of the preferred embodiments with reference to the accompanying drawings, wherein:
[0012] FIGS. 1 (A), 1 (B) and 1 (C) are partially developments of inner surfaces of bearing metals that constitute radial hydraulic bearing devices according to the related arts;
[0013] FIGS. 2 (A), 2 (B) and 2 (C) are plane views of bearing metals that constitute thrust hydraulic bearing devices according to the related arts;
[0014] [0014]FIG. 3 is a schematic illustration of a wheel spindle apparatus of a grinding machine according to the first embodiment of the present invention;
[0015] [0015]FIG. 4 is a sectional perspective view of a bearing metal according to the first embodiment of the present invention;
[0016] FIGS. 5 (A), 5 (B) and 5 (C) are partially developments of inner surfaces of the bearing metals according to the first embodiment of the present invention;
[0017] FIGS. 6 (A), 6 (B), and 6 (C) are partially developments of inner surfaces of other bearing metals according to the first embodiment of the present invention;
[0018] [0018]FIG. 7 is a graph showing relations between rotational speed of a wheel spindle and static rigidity of radial hydraulic bearings;
[0019] [0019]FIG. 8 is a graph showing relations between rotational speed of a wheel spindle and temperature of bearing metals of radial hydraulic bearings;
[0020] [0020]FIG. 9 is graph showing pressure distribution on an inner surface of a bearing metal according to the first embodiment of the present invention;
[0021] [0021]FIG. 10(A) is a sectional view of a wheel spindle showing a direction of grinding force, and FIG. 10(B) is a graph showing a relation between pressure distribution on an inner surface of a bearing metal and a position of a hydraulic pocket relative to the direction of grinding force according to the first embodiment of the present invention;
[0022] [0022]FIG. 11 is a schematic illustration of a wheel spindle apparatus of a grinding machine according to the second embodiment of the present invention;
[0023] [0023]FIG. 12 is a graph showing a relation between rotational speed of a wheel spindle and static rigidity of a hydraulic bearing according to the second embodiment of the present invention;
[0024] [0024]FIG. 13 is a graph showing a relation between rotational speed of a wheel spindle and temperature of a bearing metal according to the second embodiment of the present invention;
[0025] [0025]FIG. 14 is a graph showing a relation between rotational speed of a wheel spindle and opening of a metering orifice according to the second embodiment of the present invention;
[0026] [0026]FIG. 15 is a graph showing a relation between temperature of lubricant oil and opening of a metering orifice according to the second embodiment of the present invention;
[0027] [0027]FIG. 16 is a time chart to explain a relation between load acting to a wheel spindle and opening of a metering orifice according to the second embodiment of the present invention;
[0028] [0028]FIG. 17 is a schematic illustration of a wheel spindle apparatus of a grinding machine according to the third embodiment of the present invention;
[0029] [0029]FIG. 18 is a plain view of a bearing metal of a thrust bearing device according to the third embodiment of the present embodiment;
[0030] [0030]FIG. 19 is a graph showing relations between rotational speed of a wheel spindle and static rigidity of thrust hydraulic bearings; and
[0031] [0031]FIG. 20 is a graph showing relations between rotational speed of a wheel spindle and temperature of bearing metals of thrust hydraulic bearings.
DESCRIPTION OF PREFERRED EMBODIMENTS
[0032] [First Embodiment]
[0033] Preferred embodiments of a hydraulic bearing device according to the invention will be described hereinafter with reference to the accompanying drawings. A radial hydraulic bearing device of according to the present invention is employed, for instance, in a wheel spindle apparatus of a grinding machine as illustrated in FIG. 3. The radial hydraulic bearing devices 11 are arranged to support a wheel spindle S at inner surfaces thereof. At one end of the wheel spindle S, a grinding wheel G is attached. A driving belt B is strung between another end of the wheel spindle S and a motor M 1 , and the wheel spindle S is rotated by the motor M 1 . Referring to FIG. 4, the radial hydraulic bearing device 11 comprises a ring shape inner sleeve 12 as a bearing metal and a bearing case 13 that the inner sleeve 12 is fixed therein by such as manners of a shrinkage fit or a press fit. Plural hydrostatic pockets 14 are formed on an internal circumference surface of the inner sleeve 12 in a circumference direction and are equally distant from each other. As a shape of the hydraulic pockets 14 , for example, quadrilateral groove shown by FIG. 5(A), U-shape groove which has leg portions extended in rotational direction of the wheel spindle S shown by FIG. 5(B) or quadrangular ring shape groove that a land portion is formed at a center thereof shown by FIG. 5(C) are applicable. A land portion 15 for generating hydrodynamic pressure is defined as a portion or portions except hydrostatic pockets 14 from the internal circumference surface of the inner sleeve 12 . At a center of the each hydrostatic pocket 14 , one end of an oil-supplying hole 17 which has a throttle nozzle (not shown in Figures) is opened. The other end of the oil supplying hole 17 is connected with a oil supplying pass 16 that is defined by a circumference groove formed on a outer surface of the inner sleeve 12 and an inner surface of the bearing case 13 . The oil-supplying pass 16 is connected with a pump P. which is driven by a motor M, via an outside supplying pipe L. At an inside of the inner sleeve 12 , plural drain holes 18 are formed. One end of the each drain hole 18 is opened on the land portion 15 , and the other end of the each drain hole 18 is connected with a tank 43 via an outside drain pipe 42 . As a disposition of the drain hole 18 , for example, single drain hole 18 disposed between each hydrostatic pocket 14 such as shown by FIGS. 5 (A), 5 (B) and 5 (C), or double drain holes 18 disposed between each hydrostatic pocket 14 shown by FIGS. 6 (A), 6 (B) and 6 (C) are applicable. In a case of the quadrangular ring shape groove shown by FIG. 5(C) or FIG. 6(C), it is preferable that another drain hole 18 is disposed in the center land portion that is surrounded with the quadrangular ring shape groove. A metering orifice 41 such as an electromagnetic variable valve is disposed on a way of the outside drainpipe 42 .
[0034] At above described radial hydraulic bearing device 11 , when lubricant oil is supplied to the supplying pass 16 by the pump P through the outside supplying pipe L, pressure of the lubricant oil is adjusted by the throttle nozzle. The pressure adjusted lubricant oil is filled in the hydrostatic pockets 14 . Therefore, the hydrostatic pockets 14 generate hydrostatic pressure and the wheel spindle S is supported for the bearing metal by the hydrostatic pressure. That is, the hydraulic bearing device 11 functions as a hydrostatic bearing. Besides, the lubricant oil filled in the hydrostatic pockets 14 flows out between the land portion 15 and an outer surface of the wheel spindle S. When the wheel spindle S is rotated relative to the bearing metal, hydrodynamic pressure is generated by edge effect of the lubricant oil that is between the land portion 15 and the outer surface of the wheel spindle S. That is, the hydraulic bearing device 11 functions as a hydrodynamic bearing. Then, the lubricant oil is drained to each side of the bearing metal. In addition, the lubricant oil is drained from the drain hole 18 to the tank 43 through the outside drainpipe 42 and metering orifice 41 .
[0035] According to the hydraulic bearing device 11 of the first embodiment, since the lubricant oil is drained with not only each side of the bearing metal but also through the drain holes 18 , drainage efficiency of the lubricant oil is improved. As the result, thermal expansion of the bearing metal due to heat generating at the land portion 15 is restrained. Then, since the drain holes 18 do not interrupt continuation of the land portion 15 like the drain grooves 7 of the related art, deterioration of bearing rigidity is restrained. That is, the hydraulic bearing device 11 of the first embodiment has a capacity of static rigidity that is close to the same of the non-separated type bearing as shown by FIG. 7, and has temperature rise that is close to the same of the separated type bearing as shown by FIG. 8.
[0036] Further, according to the hydraulic bearing device of the first embodiment, since the metering orifice 41 is disposed in the outside drainpipe 42 , it is possible that bearing rigidity is controlled to adjust an opening of the metering orifice 42 . That is, as shown FIG. 10, since pressure distribution at the bearing metal changes according to opening of the metering orifice 42 , it is possible to control as follows: when high rigidity is required such as machining time by the grinding wheel G. bearing rigidity is increased by closing the metering orifice 42 ; when high rigidity is not require such as an idle time of the machining, thermal expansion of the bearing metal is decreased by opening the metering orifice 42 .
[0037] Moreover, since a capacity of static rigidity and thermal expansion can be controlled by the metering orifice 41 , a range of specification of the bearing device spreads. In the result, a freedom of a design for the bearing device increases.
[0038] Furthermore, in a case of that the metering orifice 42 is installed relative to each drain hole 18 , opening of each metering orifice 42 is adjustable individually. For example, at the wheel spindle apparatus of the grinding machine, the wheel spindle S receives a load, which is grinding resistance, in constant direction as shown by an arrow of FIG. O(A). Therefore, it is possible that bearing rigidity relative to load acting direction is increased to close the metering orifices V 2 relative to load receiving direction, thermal expansion of the bearing metal is decreased to open another valves V 1 , V 3 , V 4 as shown by FIGS. 10 (A) and 10 (B).
[0039] In addition, since pressure in the drain hole 18 dose not become negative pressure by existence of the metering orifice 42 , generating cavitation at the drain hole 18 is prevented.
[0040] [Second Embodiment]
[0041] Explanation for the second embodiment that is same constitution as the first embodiment is omitted. Referring to FIG. 11, sensors are prepared for a wheel spindle apparatus of the second embodiment in addition to the constitution of the first embodiment. An encoder 22 is attached on an end face of the wheel spindle S to measure rotating speed of the wheel spindle S. A temperature sensor 23 is attached on a way of the outside drainpipe 42 to measure temperature of the drained lubricant oil. A pressure gauge 24 is attached in the hydrostatic pocket 14 to measure pressure therein. A displacement sensor 25 is disposed between the inner sleeve 12 and wheel spindle S to measure a clearance therebetween. Each of sensors 22 , 23 , 24 and 25 is connected electrically to a controller 21 , and output therefrom is input to the controller 21 . The controller 21 is connected electrically to the metering orifice 41 to control opening of the metering orifice 41 . Here, all sensors are not required to be installed, it is possible that one or some sensors is/are installed selectively.
[0042] At above described second embodiment, controller 21 controls opening of the metering orifice 41 according to the output of the sensors 22 , 23 , 24 and 25 . As shown by FIG. 7, static rigidities of the first embodiment increase according to increasing of rotational speed of the wheel spindle S, because hydrodynamic pressure increase according to increasing of rotational speed. Simultaneously, temperature of the bearing metal increases according to rotational speed as shown by FIG. 8. Then, in the second embodiment, the controller 21 controls opening of the metering orifice 41 according to rotational speed of the wheel spindle S as a relationship of opening of the metering orifice 41 with rotational speed of the wheel spindle S shown by FIG. 14. Therefore, increase of the rigidity more than necessity is restrained shown by FIG. 12, and increase of the temperature of the bearing metal is restrained shown by FIG. 13. Similarly, as shown by FIG. 15, opening of the metering orifice 41 can be controlled according to temperature of the lubricant oil that is measured by the temperature sensor 23 . As another control mode of the metering orifice 41 , it is possible that the metering orifice 41 is controlled according to pressure in the hydrostatic pockets 14 that is measured by the pressure gauge 24 , or a clearance between the inner sleeve 12 and wheel spindle S that is measured by the displacement sensor 25 . For example, at the wheel spindle S of the grinding machine, machining resistance that acts to the wheel spindle S changes intermittently to repeat machining cycles as shown by FIG. 16(A). Then, at the bearing device of the related art, temperature of the bearing metal rises constantly regardless of load fluctuation as shown by FIG. 16(B). However, temperature rise more than necessity is restrained as shown by FIG. 16(D) by controlling opening of the metering orifice 41 as shown by FIG. 16(C) according to pressure in the hydrostatic pockets 14 measured by the pressure gauge 24 .
[0043] According to the hydraulic bearing device of the second embodiment, in addition to the effects of the first embodiment, a balance with bearing rigidity and temperature rise can be adjusted suitably to control opening of the metering orifice 41 according to rotational speed of the wheel spindle S, temperature of the lubricant oil, pressure in the hydrostatic pockets or clearance between the wheel spindle S and the land portion 15 .
[0044] [Third Embodiment]
[0045] At third embodiment, the present invention is applied to a thrust hydraulic bearing device. As shown FIG. 17, a flange portion F is formed in a center of a wheel spindle S. A front and a rear thrust bearing metals 31 are arranged to oppose to end surfaces of the flange portion F each other. Each thrust beating metal 31 is ring shape formed a center hole 32 that the wheel spindle S penetrates therein, and fixed on a bearing case C. It is possible to form directly a bearing metal on end surfaces of the bearing case C. As shown FIG. 18, four hydrostatic pockets 34 that are separated ring shape grooves are formed on a surface of the bearing metal 31 which is opposed to the end surface of the flange portion F. Portions of the surface of the bearing metal 31 except the hydrostatic pockets 34 are land portions 35 to generate hydrodynamic pressure. The land portions 35 are consist of an outer land portion 35 a , an inner land portions 35 b and spoke land portions 35 c that are formed between each hydrostatic pockets 34 . An oil-supplying hole 17 which has a throttle nozzle (not shown in Figures) is opened into each hydrostatic pocket 34 . The other end of the oil-supplying hole 17 is connected with a pump P through an inner portion of the bearing case C. On the spoke land portion 35 c , drain holes 36 like the drain holes 18 in the first and second embodiment are formed. Similarly with the first embodiment and the second embodiment, the other end of the drain holes 36 is connected with a tank 43 through a metering orifice 41 such as a an electromagnetic variable valve.
[0046] At above described thrust hydraulic bearing device, when lubricant oil whose pressure is adjusted by the throttle nozzle is supplied to the hydrostatic pockets 34 through the oil-supplying hole pass 17 , the pressure adjusted lubricant oil is filled in the hydrostatic pockets 34 . Therefore, the hydrostatic pockets 34 generate hydrostatic pressure and the wheel spindle S is supported for the bearing metal 31 by the hydrostatic pressure. That is, the hydraulic bearing device functions as a hydrostatic bearing. Besides, the lubricant oil filled in the hydrostatic pockets 34 flows out between the land portion 15 and the end surface of the flange portion F. When the wheel spindle S is rotated relative to the bearing metal 31 , hydrodynamic pressure generated by edge effect of the lubricant oil that is between the land portion 35 and the end surface of the flange portion F. That is, the hydraulic bearing device functions as a hydrodynamic bearing. Then, the lubricant oil is drained to inner and outer sides of the bearing metal 31 . In addition, the lubricant oil is drained from the drain hole 36 to the tank 43 through metering orifice 41 .
[0047] According to the third embodiment, since the lubricant oil is drained with not only each side of the bearing metal but also through the drain holes 36 , drainage efficiency of the lubricant oil is improved. As the result, thermal expansion of the bearing metal 31 due to heat generating at the land portion 35 is restrained. Then, since the drain holes 36 do not interrupt continuation of the land portion 36 like the drain grooves 7 of the related art, deterioration of bearing rigidity is restrained. That is, the hydraulic bearing device of the third embodiment has a capacity of static rigidity that is close to the same of the non-separated type bearing as shown by FIG. 19, and has temperature rise that is close to the same of the separated type bearing as shown by FIG. 20.
[0048] Further, according to the hydraulic bearing device of the third embodiment, since the metering orifice 41 is disposed in the outside drainpipe 42 , it is possible that bearing rigidity is controlled to adjust an opening of the metering orifice 42 .
[0049] Moreover, since a capacity of static rigidity and thermal expansion can be controlled by the metering orifice 41 , a range of specification of the bearing device spreads. In the result, a freedom of a design for the bearing device increases.
[0050] Furthermore, in a case of that the metering orifice 42 is installed relative to each drain hole 36 , opening of each metering orifice 42 is adjustable individually.
[0051] In addition, since pressure in the drain hole 36 dose not become negative pressure by existence of the metering orifice 42 , generating cavitation at the drain hole 36 is prevented.
[0052] It is possible that the sensors like the second embodiment are installed to the third embodiment. Then, the thrust bearing device of third embodiment provides same effects with the second embodiment.
[0053] Obviously, numerous modifications and variations of the present invention are possible in light of the above teaching. It is therefore to be understood that within the scope of the appended claims, the present invention may be practiced otherwise than as specifically described herein. | A hydraulic bearing device that supports a rotating shaft comprises a bearing metal. On a surface of the bearing metal, a hydrostatic pocket and a land portion are formed. The land portion is defined by the hydrostatic pocket and generates hydrodynamic pressure. The hydraulic bearing device further comprises a pressure fluid supplying source and an oil-supplying hole. The oil-supplying hole is opened in the hydrostatic pocket and provides pressure fluid from the pressure fluid supplying source to the hydrostatic pocket. On the land portion, a drain hole that drains the fluid is formed. Since the fluid is drained through the drain hole, thermal expansion of the bearing metal due to heat generation of the fluid is restrained. Moreover, since the drain hole does not separate the land portion, deterioration of bearing rigidity is restrained. | 5 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to darning and embroidery plates for rendering the work feeding mechanism of a sewing machine ineffective.
2. Description of the Prior Art
It is known to provide darning and embroidery plates for sewing machines enabling an operator to cover feed dog teeth and thereby prevent cloth from being fed under the sewing needle. This permits the operator to manually manipulate the work as required for darning or embroidering. Metal cover plates have been used for the purpose and these were specially fabricated with holding means engageable with mating parts on the sewing machine.
A difficulty encountered in the design of darning and embroidery plates has been that of providing a plate which is both economical to produce and can be reliably secured with ease to the machine. There are at present no satisfactory feed dog cover plates having such characteristics, and it is a prime object of this invention to satisfy the need.
SUMMARY OF THE INVENTION
In accordance with the invention there is provided a darning and embroidery plate of plastic which can be economically and easily produced as a single piece utilizing injection molding techniques, which can be quickly attached to the machine, and which after having been so attached remains reliably secured in position until intentionally removed. Such plastic plate is formed with integral pins for insertion in holes in the needle plate of a machine and with a laterally flexible arm having thereon one of the pins which is aligned with a mating hole in the needle plate by laterally flexing the arm. The resulting spreading action between the locating pins firmly secures the darning and embroidery plate in place on the machine.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view showing a darning and embroidery cover plate according to the invention in an assembled position on the needle plate of a sewing machine;
FIG. 2 is an exploded perspective view of the cover plate and needle plate of FIG. 1;
FIG. 3 is a bottom perspective view of the cover plate; and
FIG. 4 is an enlarged vertical sectional view taken through the cover and needle plate assembly.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to the drawings, reference character 10 designates a darning and embroidery cover plate according to the invention. Such cover plate 10 attaches to a needle plate 12 which mounts on pins 14 and 16 in the bed 18 of a sewing machine and is contiguous to throat plate 19. The cover plate 10 and needle plate 12 include openings 20 and 22 respectively which are in alignment when the cover plate is secured to the needle plate, and permit the sewing needle 24 to pass through these parts during endwise reciprocation of the needle by needle bar 26. As shown, cover plate opening 20 is arcuate in form, the opening has been configured to match needle plate opening 22 which is capable of accomodating zig zag movements of the needle 24. Although zig zag needle movements are not employed during darning or embroidery operations and needle opening 20 need not be arcuate, it is preferable that it be so in a darning and embroidery plate intended for use on a zig zag machine since needle damage will thereby be prevented if zig zag movements are mistakenly called for by an operator when the cover plate 10 is in place over the needle plate 12 of the machine. The underside of cover plate 10 is formed with elongated recesses 28, 30 and 32 which are provided to accomodate without interference moving feed dog elements 34, 36 and 38 that extend through openings 33, 35 and 37 respectively in needle plate 12.
Marginal edge portion 40 of the cover plate 10 includes a boss 42 which on its underside supports a pin 44 that is inserted in a hole 46 in needle plate 12 when the cover plate 10 attached to it. Marginal edge portion 40 also includes an arm extension 48 which on its underside supports a pin 50 that is inserted in another hole 52 in the needle plate at the time the cover plate 10 is attached to the needle plate 12.
The cover plate 10 including the pins 44 and 50 is an integral unit formed of a plastic material which lends flexibility and resiliency to the arm 48. Any of the polycarbonate plastic materials as well as various other types of plastic materials may be used for the cover plate 10 although a particular one of the polycarbonates sold under trade name "LEXAN" is particularly suitable for use in forming the cover plate because of its durability as well as its resiliency and flexibility. The cover plate 10 is most conveniently made and inexpensively formed using conventional injection molding techniques.
Cover plate 10 is formed with pins 44 and 50 spaced apart by a slightly greater distance a than the distance b between the holes 46 and 52 in the needle plate 12 so that it is necessary to laterally flex the arm 48 to equalize the distance between the pins and their mating holes 46 and 52 when attaching the cover 10 to needle plate 12. This is easily accomplished by gently applying pressure to the end of arm 48 tending to shorten the distance a between the pins.
After the cover plate 10 has been attached to needle plate 12 by inserting pins 44 and 50 in holes 46 and 52 respectively, the natural resiliency of the material of the cover plate which exerts a spreading action on arm 48 is effective to maintain the pins 44 and 50 in tight contact with the sides of their mating holes and the cover plate firmly in place on the needle plate until it is intentionally removed by being pryed upwardly with the finger nail or a small screw driver. As shown, pins 44 and 50 are tapered with oblique inside non-bearing surfaces 54 and 56 respectively which facilitate alignment of the pins with the holes 46 and 52, and insertion therein.
It is to be understood that the present disclosure relates to a preferred embodiment of the invention which is for purposes of illustration only, and that various changes and modifications may be made therein without departing from the spirit and scope of the invention as defined in the appended claims. | A snap-on darning and embroidery plate, provided for use in conjunction with a needle plate on a sewing machine to render the work feeding mechanism ineffective, is constructed of plastic and structured to provide a spreading action between locating pins thereon when inserted in holes in the needle plate. | 3 |
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