Apparatus and a method for treating polymeric material, such as polytetrafluoroethylene, with radiation. The polytetrafluoroethylene is moved under an electron beam in an even and consistent depth on an adapted vibratory table. The vibratory table is sealably covered which allows a controlled environment. The polymeric material can be degraded to lower molecular weight forms or reacted with other materials.

1. Field of the Invention
The invention involves radiation treatment of polymeric materials, including treatment of polytetrafluoroethylene (xe2x80x9cPTFExe2x80x9d) to degrade the material into lower molecular weight forms. That is the electron beam degrades the molecular chain of the polymer thereby reducing the molecular weight. More specifically, the invention has to do with the use a vibratory table to move polymer, such as PTFE, in an even layer, that is at a consistent thickness or depth under an electron beam. The vibratory table apparatus and methods in accordance with the present invention accomplish several desired improvements over apparatus and methods known in the art, and resolves certain deficiencies associated with radiation treatment, particularly radiation treatment of fluoropolymers such as PTFE. The apparatus and methods provide an even layer of material on a continuous basis under an electron beam which allows for more efficient processing without radiation losses and labor requirements of other processes, provides for an enclosed environment which protects against gas evolution and provides for continuous cooling. These and other advantages over radiation process known in the art are achieved with the apparatus and methods of the invention as described herein.
The polymeric material is treated in an enclosed environment which permits treatment to be performed in dedicated environments, including an inert environment and environments rich in particular gases, such as oxygen and nitrogen, or combinations of gases. This feature of the invention allows the apparatus and process to be adapted to permit reaction between materials on the table and chemicals permitted to enter the environment where the radiation treatment occurs. The method can also be adapted to combine at least two materials on the vibratory table to allow for a reaction or reactive coating, such as copolymerization, between the materials using the energy of the electron beam. The apparatus comprises a dual loop cooling water system which provides for the efficient removal of the significant heat generated during the radiation processing, and other cooling systems dedicated to other pieces of apparatus used in the process. The material can be delivered to the vibratory table by any means capable of transporting polymer materials, including a pneumatic flow system, and any means capable of transporting polymer materials, including a pneumatic flow system, can be used to convey treated material from the area of the vibratory table. The radiation processing can embrittle the polymeric material due to molecular wright degradation thus facilitating the physical breaking of the treated polymers in the pneumatic flow system to allow for the reduction in material particle size. Use of a pneumatic flow system with the vibratory table provides for the reduction of the particle size of the polymeric material to about 30 to about 3,000 microns.
2. The Related Art
Radiation treatment has been employed to polymerize organic substances and for treatment of polymers. For example, U.S. Pat. No. 2,921,006 to Schmitz et al. describes polymerization of monomers with an electron beam which is exposed to the monomer in a vacuum chamber partially filled with a cooling medium. An embodiment of the invention in U.S. Pat. No. 2,921,006 involves the continuous treatment of monomer moved through the electron beam on a thin sheet of stainless steel, about 0.002 inches thick, with side flanges of resilient material to prevent material dropping off the sides of the sheet. This patent does not involve the degradation of polymer and does not address process concerns and parameters pertinent to polymeric degradation with an electron beam, and particularly degradation of PTFE.
U.S. Pat. No. 3,081,485 to Steigerwald involves treatment of thermoplastic strands which have softening points below their decomposition points. The strands are moved through an electron beam in a vacuum chamber to soften the thermoplastic. U.S. Pat. No. 5,856,675 to Ivanovich et al. concerns the movement of polymer, on a continuous basis using a conveyor system through an electron beam to cross-link the material.
Radiation can be used to degrade the molecular weight of polymers such as PTFE. For example, U.S. Pat. No. 3,766,031 to Dillon discusses radiation treatment of PTFE with an electron beam at between about 5 and 25 Mrads which renders the PTFE capable of being comminuted to microfineness. This comminuted PTFE is useful as a dry lubricant, for example, in paints and inks. The process employed in U.S. Pat. No. 3,766,031 is not efficient and not appropriate for modern processing because there is no method for cooling the PTFE and the PTFE is unevenly treated. U.S. Pat. No. 4,220,511 to Derbyshire discusses the degradation of unsintered PTFE to be ground into a powder with an average size less than 10 microns. A combination of a radiation at 50-150 Mrads and heat at 150xc2x0 F. to 600xc2x0 F. for approximately one half hour is used in the process to degrade the PTFE. U.S. Pat. No. 4,029,870 to Brown, et al. discusses dry lubricant PTFE obtained by subjecting the PTFE to xcex3-radiation at doses of between 2 and 20 Mrads and subsequently comminuting the PTFE to microfiness. U.S. Pat. No. 5,891,573 to Nueberg et al. addresses subjecting PTFE handled at a temperature below 66xc2x0 F. to a radiation source to obtain friable PTFE, and the PTFE may be combined with a wetting agent prior to irradiation.
Conventional methods of treating PTFE with electron beams, in use today, including those involving the use of trays are inefficient and results in PTFE products that are unevenly treated. The conventional methods result in uneven radiation treatment, and experiences other deficiencies, including the inability to control the processing environment, process gas evolution and the inability to effectively remove heat.
Several factors contribute to the inefficiency of tray irradiation of PTFE. The most significant occurs as a result of the beam penetration characteristics through the depth of material in the tray. Typically, the dose at the surface is taken as the nominal dose for the material. Beam energy and/or material depth is adjusted so that an equal dose is effected at the opposite surface of the material. Radiation which passes entirely through the product is not utilized. Radiation in excess of the nominal dose is likewise not used. This causes inefficiency, and in some instances may result in undesired properties of the resultant product. This depth-dose characteristic can cause processing inefficiency of up to 50%. Variations in material depth in the tray, gaps between the trays, and overscan of the tray, which is necessary to assure complete and uniform irradiation, can cause additional inefficiencies of approximately 5-15%.
The depth-dose characteristic, overscan and variations in material depth that occurs with tray processing all contribute to uneven treatment of the PTFE. Consequently, some of the PTFE may be overly treated and other portions of the PTFE may not receive adequate treatment. This results in inconsistent properties and, hence, unpredictable product quality of the processed PTFE.
Processing on trays can only be performed in batches requiring time and labor to place material on the tray and move trays into position and from the processing area after treatment. This requires that a human being be so integrally involved in the process that processing is generally performed in ambient conditions. Thus, the conventional tray process is limited in the inability to effectively control the environment where the processing occurs, and the process cannot be readily adapted to allow for reaction between PTFE and other materials, or to react or combine polymers in general.
Hydrogen fluoride gas generation from radiation treatment of fluoropolymers, such as PTFE, is a problem associated with the tray method and other known processes for degradation of fluoropolymers such as PTFE with an electron beam. Presence of hydrogen fluoride gas presents worker safety and environmental control issues. As discussed below, the hydrogen fluoride gas will interact with steam or condensed water resulting from cooling water methods which results in generation of hydrofluoric acid that not only causes additional worker safety issues and environmental control issues, but causes potential corrosion of equipment.
Radiation treatment of PTFE generates large amounts of heat and successful industrial processes for treatment of PTFE require removal of the thermal energy due to the electron beam from the processing area. The tray method is limited because, as in U.S. Pat. No. 3,766,031, there is no provision for heat transfer.
When methods of heat transfer such as direct cooling of the PTFE or water jackets are applied in conventional radiation processes, these methods are generally inefficient and have serious drawbacks. A conventional method for cooling during tray processing is applying water directly to the PTFE. As discussed above, the hydrogen fluoride gas generated from the electron beam treatment of the PTFE reacts with the cooling water to form caustic hydrofluoric acid. Besides the previously discussed health, safety, and corrosion issues caused by hydrofluoric acid, the direct cooling method generates an acidic waste stream which may require treatment or special considerations for disposal and other environmental controls. The hydrofluoric acid is caustic and this can corrode the apparatus and equipment used in the PTFE treatment process and gives rise to worker health and safety issues. Direct cooling of PTFE with water also inhibits the degradation process, preventing proper degradation of the PTFE and resulting in an inferior product.
Another method to remove heat during PTFE radiation treatment is the use of cooling water jackets. Use of conventional cooling water jackets to remove heat during PTFE radiation treatment generally require large volumes of water to effectively remove the vast amounts of heat generated in the process. Thus, cooling water jackets require large amounts of water resources which add to the costs and material requirements for PTFE processing. Also, during the cooling process with a water jacket, condensation can form during cooling which can mix with the hydrogen fluoride gas to form caustic hydrofluoric acid. As discussed above, hydrofluoric acid gives rise to wastes, such an acidic waste stream that may require special treatment or considerations for disposal and other environmental controls, corrosion of the apparatus and equipment and worker health and safety issues.
One method employed to inhibit hydrofluoric acid production, during the cooling process with a cooling jacket, is to heat the water to a temperature above the dew point of the gas in the surrounding environment to avoid condensation. This, however, reduces the heat transfer capabilities of the water thereby requiring larger amounts of water than cooling processes that do not require heated water. Furthermore, in order to elevate the temperature of the water, water to water heat exchangers may be necessary adding complexity to the process and equipment combined with additional capital and operating costs.
Efforts have been made to develop processes that provide for more even radiation treatment of PTFE to avoid the problems associated with the tray method and to avoid the traditional drawbacks associated with cooling systems. An apparatus and method for degrading PTFE by propelling the polymer in a fluidized bed of hot air into the path of an electron beam is disclosed in U.S. Pat. No. 5,296,113 to Luniewski. The apparatus has a means for generating an electron beam, a chamber where the PTFE interacts with the electron beam and a separator. Heated air at high pressure is injected into the chamber to move the PTFE around the chamber and through the path of the electron beam. The PTFE is said to be degraded to particles with sizes ranging from 10 to 400 microns which then can be use as a dry lubricant. The apparatus relies on direct air cooling of the PTFE during the process, and the apparatus is equipped with cooling water jackets for the bottom of the chamber and an aperture at the top of the chamber where the electron beam enters the chamber. The cooling water jackets are designed to cool the chamber, and not the PTFE, and the apparatus relies on rapid treatment of the PTFE so that the PTFE particles are not affected by the cooling water in the cooling water jackets.
U.S. Pat. No. 5,149,727 to Luniewski describes a method and apparatus for treating and degrading PTFE for use as a dry lubricant which utilizes simultaneous irradiation, grinding, agitation and air cooling. The apparatus has a means for generating an electron beam, and a grinding vessel. The grinding vessel includes air jets which can inject air at up to 200 pounds per square inch (xe2x80x9cpsixe2x80x9d) into the grinding vessel and paddles. The paddles cause the PTFE to move haphazardly into the path of the electron beam in the grinding vessel. The air injection cools the PTFE within the grinding vessel to a temperature below 620xc2x0 F., the melting point, and also assists in the movement of the particles within the vessel. The PTFE particles are degraded, primarily, by the radiation and grinding action that occurs within the vessel. The air injection alleviates the need for a cooling water system for the apparatus. A classifier attached to the apparatus causes the degraded PTFE particles to exit the grinding vessel when a desired particle size is achieved. The apparatus can treat PTFE on a batch basis in a typical time of four to nine hours and the process appears primarily developed for batch processing although the process is said to be adaptable for a continuous operation.
Movement of PTFE through an electron beam in a ribbon-blender type apparatus is discussed in U.S. Pat. Nos. 4,777,192 and 4,748,005 to Neuberg et al. The apparatus comprises a means for generating an electron beam and a chamber where PTFE is subjected to the electron beam. Material is delivered to the chamber by a screw conveyor. Stirrer paddles are located within the chamber which move the PTFE within the chamber. The chamber is also equipped with means for permitting flow of air into the chamber which tends to provide fluidizing of the PTFE. This facilitates movement of the paddles, promotes PTFE degradation which requires oxygen and aids the cooling process provided by the primary cooling water jacket. The cooling water must be heated prior to entering the cooling water jacket to avoid condensation.
The product resulting from the apparatus and methods described in U.S. Pat. Nos. 4,777,192 and 4,748,005 is said to be of poor quality and the powder particles treated with radiation in the ribbon-blender type apparatus are said to have widely varied sizes. The process is criticized as not cost effective in that particles mechanically comminuted to smaller sizes need less radiation and larger particles do not receive sufficient oxygen during treatment thus affecting the core. The process described in these patents is said to be basically, a batch process and requires large energy expenditures.
It has now been unexpectedly discovered that the molecular weight of polymeric material, such as PTFE, can be effectively degraded on a batch or continuous basis by movement of the material on a specially adapted vibratory table. The vibratory table is adapted to include a means for generating an electron beam, cooling water systems, conduits and means for delivering PTFE to the table so that the material, such as PTFE, moves under the electron beam at an even depth (e.g. consistent thickness) as a result of the combination of the delivery means and vibratory action of the table. The cooling water system is a dual loop system which permits effective heat transfer at the vibratory table within the design requirements of the table. Furthermore, the cooling water is at an initial temperature of about 55xc2x0 F. to 65xc2x0 F. which limits condensation, this consequently limits the potential for generation of hydrofluoric acid thus achieving a practical system using a cooling water jacket while alleviating the drawbacks encountered when water jackets are used with conventional and other known methods and apparatus. Also, dry air can be introduced at the trough of the vibratory table which inhibits condensation.
The apparatus and method comprising a vibratory table accomplishes several fundamental improvements over methods and apparatus known in the art. The apparatus and method transports an even layer of material on a continuous basis thus greatly reducing the depth-dose characteristics and other radiation processing inefficiencies associated with known methods, including the tray method; provides for an enclosed environment at the point of treatment which among other benefits protects against gas evolution thereby addressing hydrogen fluoride gas issues associated with known apparatus and methods and provides continuous and effective cooling which minimizes hydrofluoric acid production. When adapted with a pneumatic transport system to deliver material to and from the vibratory table area, the apparatus and process provides the added benefit of reducing the particle size of the material to between about 30 microns and about 3,000 microns.
Movement of material through vibratory action, in general, is known, however the specific concerns pertinent to radiation processing, that is movement of an even layer of material along a vibratory table with effective heat transfer, are not addressed. For example, U.S. Pat. No. 4,313,535 to Carmichael concerns an excited frame, vibratory conveying apparatus. U.S. Pat. No. 4,844,236 to Kraus concerns a vibratory conveying apparatus with a xe2x80x9cv-shapedxe2x80x9d trough useful for conveying material up an incline. A vibratory conveyor with a flexible trough attached to a spring bed which vibrates causing the flexible bed to flex and change its static shape thus thrusting the material upwards, which is particularly useful for sticky or adhesive materials, is discussed in U.S. Pat. No. 4,482,046 to Kraus. The apparatus in U.S. Pat. No. 4,482,046 can be adapted with a cooling system comprising a cooling jacket beneath the bed of the trough that uses air or water as the cooling medium, and the bed may be perforated with small holes to permit air or water flow and facilitate heat transfer. None of these patents discuss the requirements necessary for a vibratory table to deliver an even layer of material, such as PTFE, under an electron beam, and these patents do not address the criteria necessary for radiation treatment, in particular the removal of the significant heat generated at the vibratory table during radiation processing or cooling systems capable of performing in accordance with the requirements necessary for radiation treatment of fluoropolymers.
It has been unexpectedly discovered that the molecular weight of PTFE can be degraded efficiently and minimizing the problems associated with treatment of PTFE on a tray, and other processes known in the art. The apparatus and method used for the radiation treatment of material, such as PTFE, comprises 1) a vibratory table adapted for radiation treatment in an enclosed environment, 2) a dual loop cooling water system which effectively removes heat from the vibratory table, 3) a means for generating an electron beam, 4) a device that delivers material to the vibratory table which, along with the vibratory action of the table, allows for movement of an even layer of material beneath the electron beam, 5) cooling water systems for other apparatuses used in the method and 6) means to transport the material to the apparatus and to transport treated material from the apparatus to a staging and/or packaging area. The system is preferably operated on a continuous basis.
All percentages set forth herein are, unless otherwise noted, weight by weight percent.
A method and apparatus are described herein which provides for radiation treatment of material, preferably PTFE, which treatment can be performed on a continuous or batch basis. The material is transported under an electron beam on a vibratory table. The electron beam scans an aperture in a cover on the vibratory table which has a window below which the electron beam breaks the molecular chain of the polymer thereby reducing its molecular weight. The use of a vibratory table, combined with means for delivering material to the table, allows for an even layer of material to be moved under the beam, that is the material retains a consistent thickness as it moves along the vibratory table and under the electron beam. Thus, the radiation dosage can be adjusted to conform to the depth of material on the vibratory table, thereby alleviating the problems and inefficiencies associated with conventional methods and apparatus caused by the depth-dose characteristic, overscan and the need for a nominal dose. The method and apparatus described herein are superior to the tray methods and other known methods of treating polymeric material such as PTFE because the material is moved under the beam on a continuous basis without any gaps and, as such, efficiency losses associated with product gaps during treatment are alleviated. The method and apparatus using the vibratory table results in a degraded polymer product that is superior to those obtained through conventional and other known methods and the degraded polymer product treated on the vibratory table does not have the inconsistent properties and unpredictable product quality associated with degraded polymeric material subjected to radiation treatment by known methods and apparatus. The material processed on the vibratory table will also have better processability than material made with known processes.
The apparatus used in conjunction with the method comprises a system for delivering the material to the apparatus for treatment and a system for removing the material from the apparatus. These systems may be preferably pneumatic, however, any system capable of moving polymers is acceptable. The system for moving material to and from the processing area may be equipped with a separator or classifier that removes from the conveying system larger pieces created from fusion under the electron beam. Such a separator or classifier may also be used to automatically recirculate oversized particles back into the system. In one embodiment, two delivery lines may be co-joined which allows for mixing of polymers or other material in a delivery line so that a blend of polymers are delivered to the vibratory table. This embodiment is particularly useful when a reaction between polymers is desired which requires the energy of the electron beam. As such, the method and apparatus can be used for reactive coating to form co-polymers, including co-polymers comprising PTFE.
The apparatus is equipped with a unique system for delivering material to the vibratory table. PTFE, or other polymers, are placed on the vibratory table through a distribution chute specifically designed to provide even spreading of polymer on the trough of the vibratory table and compensate for pulse release of material from a plug flow rotary valve used to remove the material from a delivery line. In the embodiment involving pneumatic transport of PTFE, for example, PTFE is released from the pneumatic transport system to a plug flow rotary valve which moves the PTFE to the distribution chute. Thus, in this embodiment, the chute both evenly distributes the PTFE on the trough and compensates for the action of the plug flow rotary valve.
The distribution chute, which is in the shape of a hollow cone bisected in half, has a top opening defined by a rim which is half circular in shape and hollow with a diameter preferably about six inches, a hollow open conical section with an open annular space extending downwardly from the top opening to an opening at the bottom of the conical section, a bottom opening, defined by a rim which is hollow and a half circle with a diameter exceeding the diameter of the top opening. The hollow cone shaped distribution chute may be covered. The distribution chute comprises an internal directing plate which can be adjusted to equalize material flow across the trough of the vibratory table. Preferably the diameter of the bottom opening is approximately the size of the width of the bed of the vibratory table. A recessed flap is attached to the end of the distribution chute and extends angularly downward towards the vibratory table. The recessed flap restricts flow thus facilitating even distribution on the trough. Material enters the distribution chute at the top opening and then moves in a downward direction expanding axially to the diameter of the open conical section as the material descends in the conical section. The material leaves the distribution chute through the bottom opening and recessed flap and is thereby placed onto the trough of vibratory table in an even layer, and the vibratory action of the table maintains the even layer (e.g. consistent thickness) as the material passes beneath the electron beam. The distribution chute comprises an internal directing plate which can be adjusted to equalize the flow of material across the trough of the vibratory table. The chute assists in distribution of material as well as provides a continuous flow to the trough of the vibratory table.
The material is subjected to treatment on a vibratory table which comprises a cover that is sealed with the table to allow for control of the environment where the radiation processing occurs. The cover also has an aperture to accommodate a window for the scanning electron beam which allows the energy of the electron beam to interact with the material on the table. The window, which when removably affixed to the cover becomes a component of the cover, functions, in part, to enclose the environment at the point of radiation treatment, such as at the trough of the vibratory table, while allowing the electron beam into the enclosed environment for treatment. Thus, the window may be made of any material that does not significantly resist the transmission of the electron beam. In an embodiment of the invention, the window comprises a titanium sheet and PVC material may be wrapped around the opposite ends of the titanium sheet, with, optionally, a metal or composite frame to provide structural support to the titanium sheet and allow for replacement or change-over of the window. The window may also comprise a plurality of titanium sheets stacked upon one another with two opposite ends with PVC material wrapped around opposite ends of the plurality of titanium sheets and the plurality of titanium sheets may reside within a metal or composite frame to give structural support and provide for ease of change-over or replacement of the window. The window may be equipped with a cooling system.
The electron beam provides energy for treatment of material, such as the degradation of the molecular weight of PTFE and/or reaction of PTFE with other polymers and chemicals. Through degradation the molecular weight of the material is reduced. The vibratory table is capable of flow rates up to about 5,000 pounds of material per hour, such as up to about 2,500 pounds of material per hour. When a pneumatic flow system is used to transport the material to and from the vibratory table, the pneumatic transport combined with the radiation processing which causes embrittlement of the polymer, allows for particle size reduction of the polymer, and the material can be reduced to a particle size of between about 30 microns and about 3,000 microns in single or multiple passes beneath the beam.
The vibratory table is adapted to accommodate a means for generating an electron beam. The electron beam can be generated by a particle accelerator which energizes and accelerates electrons which are then focused into a beam and directed by a scan horn to the window at an aperture in the cover of the vibratory table. A turbo vacuum pump creates a vacuum for the accelerator and electron beam. The beam moves through the window and into the path of the material as it moves on the bed of the vibratory table under the window thus causing the degradation of the molecular weight of the material. The radiation dosage is adjusted depending on the depth of material on the bed. For degradation of polymeric material, such as PTFE, the dosage can be about 2 megarads (xe2x80x9cMradsxe2x80x9d) to about 10 Mrads at a setting of about 1.5 Megavolts (xe2x80x9cMeVxe2x80x9d) with amperage settings of about 5 to about 40 milliamps. However, material depth on the bed can be adjusted depending on the dosage. The depth of material on the bed as the material passes under the electron beam is nearly constant. The material may be at a near even depth, that is a consistent thickness of between about xe2x85x9 inches to about xc2xd inches, depending on the bulk material density.
The extent of degradation of the molecular weight of the material is a function of the depth of material on the bed of the vibratory table (that is the thickness of the material), the dosage and the size and/or original molecular weight of the material. Thus, to achieve a desired molecular weight of the material, repetitive treatments may be necessary. Through experimentation, the depth of material, radiation dose and number of passes necessary to achieve a desired molecular weight can be determined and thus precise standards developed. When pneumatic transport system is used in conjunction with the radiation processing, the parameters such as depth of material, radiation dose and number of passes through the apparatus to achieve a desired particle size having material of desired molecular weight can be determined. Generally, particle sizes of about 100 microns to about 3,000 microns can be achieved with a single pass through the apparatus with pneumatic transport and from about 30 microns to about 3,000 microns with multiple passes. As such, without extensive product analysis or separation techniques, each time the product, such as PTFE, is treated, the parameters effecting molecular weight degradation can be determined and available for commercial use of the method and apparatus. When equipped with a pneumatic transport system, the parameters affecting particle size reduction may also be determined. Accordingly, the apparatus can be operated on a routine basis without the need for expensive and cumbersome analysis each time material is processed on the table to determine if additional processing is necessary.
A means to comminute the material after radiation processing may also be used to reduce the polymeric material to a desired particle size after radiation processing. For example, the polymeric material may be pulverized by one or more mills or micronized by one or more jet mills.
The material is placed on the trough of the vibratory table through the distribution chute which provides for even distribution of material on the bed. The vibratory table can be slightly inclined at an angle, and, if so, the material is deposited on the table at the inclined end of the table. The process, however, can be operated with the vibratory table in the horizontal position. The incline of the table is particularly helpful with respect to the cooling water system by providing that water will fill the cooling water jacket, and in particular channels within the jacket, while maintaining uninterrupted contact with the underside of the trough of the vibratory table. The material then flows in a forward direction along the trough and under the path of the electron beam. The table is capable of flow rates of up to about 5,000 pounds of material per hour, preferably up to about 2,500 pounds of material per hour. The trough of the vibratory table comprises a bottom and sides protruding at an upward angle from each side edge of the bottom of the trough and flanges that protrude from the sides at an angle of repose about horizontal with reference to the bottom of the trough. The upwardly protruding sides prevent PTFE from falling off the sides of the trough. The trough is preferably stainless steel made of a thin material, preferably no more than about 0.08 inches to about 0.37 inches thick, preferably about 0.125 inches thick. The upper side of the trough, that is the side which holds the material, is highly polished, up to about a 240 grit finish. The thinness of the trough facilitates heat transfer and the polished surface serves to both facilitate heat transfer and reduce friction between the material and trough to allow for smooth movement and maintain the desired even depth of the material on the table.
The electron beam is directed to the window, which is rectangular and is located above the table at approximately the mid-point of the trough, and scans the window. The window may be positioned in any manner at the midpoint of the cover, depending on the size of the scan horn of the particle accelerator, and may be located perpendicular to the direction of material flow or at an angle. The entire table is covered by a cover attached to the flanges and the window is placed into an opening, an aperture, in the cover and the window is attached to the cover. One or a plurality of gaskets, preferably two inch silicone gaskets, frame the material of the window. The window is secured to the cover by a variety of means, including gaskets, frames, welds or any other means, or combination of means, to secure the articles together while maintaining a seal for the enclosed environment. A full face gasket may be located over the silicone gasket to seal the window against a stainless steel plate which is then tightened down to secure the window and plate against the table cover, thus securing the window to the cover.
The material is treated in an enclosed environment. This is accomplished by the cover and attached components which are attached to the vibratory table. The enclosed environment allows for treatment in an infinite number of atmospheric conditions within the enclosed environment at the vibratory table. For example, the treatment can occur in an oxygen rich environment, inert environment or nitrogen rich environment depending on needs and requirements. The enclosed environment also allows for chemical treatment and reaction of the material. The apparatus can easily be adapted to provide for chemical reactions of the polymeric material at the table, such as PTFE, and substances permitted into the atmosphere in the enclosed environment. Generally, oxygen facilitates degradation of PTFE and, as such, a preferred embodiment of the invention is to charge the enclosed environment at the vibratory table with dry air which both facilitates PTFE degradation and inhibits condensation.
The cover, and enclosed environment, also alleviates the problems associated with the generation of hydrogen fluoride gas associated with conventional radiation treatment methods for fluoropolymers, such as PTFE. Because the environment at the treatment area is enclosed, hydrogen fluoride gas cannot migrate from the table thus limiting effects on equipment and limiting worker safety concerns. Also, the vibratory table is located within a vault further limiting the potential for hydrogen fluoride gas migration. The cooling water system, by use of water which enters the system at about 55xc2x0 F. to 65xc2x0 F., also inhibits condensation. Furthermore, the controlled environment allows the operators to create conditions which inhibit hydrogen fluoride gas production or condensation within the enclosed environment at the vibratory table. As discussed above, dry air can be used which inhibits condensation. Thus, the enclosed environment at the vibratory table inhibits or alleviates the problems of equipment corrosion, worker safety concerns and environmental control issues arising from hydrogen fluoride generation, and hydrofluoric acid production, that are generally associated with radiation treatment systems for fluoropolymers known in the art, including but not limited to tray methods.
The vibratory table is equipped with a jacket which surrounds the undersides of the bottom and sides of the trough. Cooling water, or other heat transfer fluid media, is a circulated in a continuous closed loop to channels located and in contact with the underside of the trough, including the upwardly protruding sides. The cooling water or other heat transfer media, flows opposite to the direction of material on the vibratory table, which both facilitates heat transfer and allows for gradual water heating which further inhibits the formation of condensation and formation of hydrofluoric acid when PTFE or other fluorinated polymers are treated. The water, or other heat transfer media, is circulated at a flow rate of about 15 to about 25 gallons per minute (xe2x80x9cgpmxe2x80x9d) at pressure about 5 psi to about 7 psi. Heat transferred to the water from the table is removed from the water in the closed loop through a heat exchanger. The heat exchanger uses a heat transfer medium, preferably a mixture of ethylene glycol and water to remove heat from the cooling water. The heat transfer medium, such as ethylene glycol and water, is circulated between the heat exchanger and a chiller in a separate loop, independent of the closed loop for the vibratory table, thus the cooling water system for the vibratory table is a dual loop system. Other pieces of equipment used in the method also have cooling systems, some of which may also use an ethylene glycol and water mixture as a heat transfer medium which can be cooled in the same chiller used to remove heat from the heat transfer medium used for the dual loop system for the vibratory table.
As will be readily understood by one skilled in the art, control equipment appurtenant to the apparatus is necessary for the system to operate. These include, but are not limited to; piping, circulating pumps, valves, blowers, coolers, power sources and filters. Also, the system is controlled from a station which allows the operators to control flow variables with the aid of microprocessors.
In general, material, such as PTFE, is moved to a flake unloader-separator where it is mixed with air, and the material is then fed under gravity to a feed hopper. The material is then transported to a plug flow rotary valve which then allows the material to flow under gravity into the distribution chute. The distribution chute evenly distributes the material onto the trough of the vibratory table and the material moves in the trough under an electron beam. After processing, the material moves to the end of the trough opposite to the distribution chute where it drops under gravity into a finished product hopper. The material exits the finished product hopper through a rotary valve and is then transported from the area of the vibratory table by a second transport system which may be a pneumatic transport system. Finished product may be moved to a packaging crate or returned to the product hopper for further treatment. The process can be adapted to include a separator or classifier that removes from the conveying system larger pieces created from fusion under the electron beam and can also be used to automatically recirculate over-sized particles back into the apparatus.

Vibratory table apparatus and associated equipment and methods for radiation treatment of polymeric materials


A multi-chip semiconductor device capable of selectively activating and deactivating the individual semiconductor chips of the device and a chip enable method thereof are included. The individual semiconductor chips of the device are activated and deactivated in accordance with internal chip enable signals.

1. Field of the Invention
Embodiments of the invention relate to a multi-chip semiconductor memory device with a plurality of memory chips built into one package and a related method of selectively enabling a memory chip within the device.
This application claims priority to Korean Patent Application No. 10-2004-0104202, filed on Dec. 10, 2004, the subject matter of which is hereby incorporated by reference in its entirety.
2. Description of the Related Art
The demand for small and diverse mobile devices such as PDAs, 3G mobile phones, digital still cameras, etc., has long been met by increasing the integration density and therefore reducing the size of the constituent components of semiconductor devices. However, continued reduction in the size of the constituent components in order to achieve even higher integration densities for contemporary semiconductor devices becomes increasingly difficult and is characterized by high cost and large amounts of development time. Accordingly, multi-chip packaging technology has recently been used in such mobile applications as an alternative to the use of increasingly dense semiconductor devices. A multi-chip package generally comprises several chips (e.g., memory chips, such as NOR flash memory chips, NAND flash memory chips, SRAM chips, UtRAM chips, etc.) mounted in a single package. In general, a multi-chip package has a structure in which two, four, or more homogeneous memory chips are vertically stacked one on top of the other. Thus, semiconductor devices formed using multi-chip package technology can reduce the semiconductor device mounting area within a host device by 50% or more, as compared with the use of separate semiconductor devices.
However, the presence of multiple chips within a multi-chip package results in the use of numerous pins (e.g., address pins, control pins, data I/O pins, etc.). This "high pin count" makes it difficult to construct a multi-chip package system. To address this problem, a plurality of memory chips in the multi-chip package may be arranged to share external pins. Unfortunately, the sharing of external pins by a plurality of memory chips within a multi-chip package generally precludes the use of a chip selection function.
FIG. 1 is a schematic diagram of a conventional multi-chip package, i.e., a dual die package (DDP) comprising a stacked arrangement of two homogenous chips in a single package. FIG. 2 is a timing diagram illustrating an operation of the conventional multi-chip package shown in FIG. 1.
Referring to FIG. 1, semiconductor chips 10 and 20 (which may be, for example, NOR flash memory chips, NAND flash memory chips, SRAM chips, UtRAM chips, etc.) are mounted in one package. An external chip enable signal nCEx activates semiconductor chips 10 and 20 for operation. In this case, although only one semiconductor chip will actually operate after the given external chip enable signal nCEx, both of semiconductor chips 10 and 20 are activated. Although it is not required to operate, the "not-to-be-selected" semiconductor chip nonetheless is still activated and dissipates power accordingly. A method of effectively avoiding this circumstance and thereby reducing the power dissipation of a multi-chip semiconductor package would be beneficial.

Low power multi-chip semiconductor memory device and chip enable method thereof


Ink jet printhead comprising a driving and encoding circuit (20) having a grid-like structure, including a plurality of inputs (24), a plurality of selecting elements (12), a plurality of actuating elements (IC) and at least one identifying element (21) of said printhead. Each identifying element (21) is associated with a corresponding selecting element (12) and corresponds to nodes arranged along a row or column of said grid-like structure, and is scanned, together with said actuating elements (11), during a preliminary checking step.

The constitution and general mode of operation of a thermal type ink jet printhead, and in particular of the type known as "top shooter", i.e. that emits the ink droplets in a direction perpendicular to the actuating assembly, are already widely known in the art, and, therefore will not be described in detail here, while only some characteristics of relevance for the purposes of the understanding of this invention will be described more particularly.
With reference to FIG. 1, an integrated printhead (head) 10, according to the known art, is made of an integrated circuit, for instance NMOS or bipolar type and comprises a plurality of nozzles 31, positioned on the head 10 according to a predefined order and suitable for ejecting ink on a medium, generally of paper, and a plurality of inputs or contacts 23; provided for connecting the head 10 to an external control circuit, suitable for commanding the selective actuation of the various nozzles 31.
The known head 10 (FIG. 2) is made of a grid-like driving circuit (M×N) comprising a plurality M of actuating assemblies 14. Each actuating assembly 14 in turn comprises a plurality N of selecting-elements or transistors 12 and an equivalent number of actuating elements or resistors 11 which are provided for causing, in a known way, ejection of the ink from the nozzles 31.
Also described by the U.S. Pat. No. 5,363,134 is an integrated printhead that comprises an encoding circuit, in which, by burning programmable fuses, information can be stored about the general characteristics of the head, such as for instance: colour head, its resolution, number of nozzles.
The encoding circuit is integrated on the same substrate as the selecting and activating circuit of the resistors and is composed of a row of programmable fuses, each of which is connected in series with a transistor.
Besides, each couple comprising a fuse and a transistor of the encoding circuit, is permanently connected to an Address Line and has the advantage of permitting reading of the coding stored without increasing the number of head connections.
It is in fact advantageous to have the possibility of identifying, through the printer's control circuit, a set of head characteristics, stored during the production of the head, that can cause a non-uniformity of operation between the various nozzles, considerably worsening the print quality.
Some of the characteristics that may be stored are, for instance, misalignments or differences of shape, diameter or center distance between the nozzles.
In possession of this information, the control circuit can compensate, by varying the energy supplied to the resistors, any differences in volume of the ink droplets or of speeds which are caused by these non-uniformities.
This solution has the disadvantage, however, of adding an encoding circuit, formed by N couples of fuses and transistors, where N is the number of addresses in the grid, to those already existing on the head, with a relative increase in the surface area of the integrated circuit and greater costs and manufacturing difficulties. In addition, the encoding circuit can contain at most N fuses.

Integrated printhead with encoding circuit


A pillowcase alone and in combination with a unique pillow design which provides an interior pocket open at an outer margin thereof for receiving and protectively storing small articles or objects such as a watch, jewelry, small personal mementos, notes and cards, photos, soft sculptures and the like. In the preferred embodiment, the pillowcase has a generally rectangular shape adapted to receive and cover two thin pillows together, or alternately, a conventional pillow. A pocket, smaller than the main portion of the pillowcase, formed continuously with, or as an extension of, each side panel of the pillowcase, is sewn together around exposed outer margins thereof. When folded inwardly, the pocket is positioned or tucked within the interior of the pillowcase against a conventional pillow, between or against two thin pillows, or within or against a pillow with a pocket-receiving cavity. The pocket is then open to receive the articles.

1. Field of the Invention
This invention relates generally to pillows and pillowcases, and more particularly to a pillowcase structured to include an interior pocket for storing small articles.
2. Description of Related Art
Multi-function pillowcases alone and in combination with a pillow having various storage means are well known.
U.S. Pat. No. 2,962,731 to Bounds, disclosed is a pillow in which a hollow core is built and is fastened closed by a pair of flat springs.
U.S. Pat. No. 6,668,400 to Nichols et al., disclosed is a pocket contained within inside hem of bedding in which hem is at the open end of pillow case (as an example a pillow is illustratively shown).
U.S. Pat. No. 6,216,297 to Lemke, disclosed is specifically a travel pillow also used as a carrying case, a travel pillow-suit case with handle or strap.
U.S. Pat. No. 4,222,468 to De Fries, disclosed is a combination portable storage container and headrest constructed using a removable, rigid tube and has a handle for carrying the unit.
U.S. Design Patent No. 397902 to Knorreck, disclosed is an activity pillow for children constructed with various working and removal parts which are covered with a button-down flap.
U.S. Design Patent No. 320522 to Deremiah, disclosed is a combined pillowcase and multiple pillow assembly. It is constructed to receive multiple pillows at one time and is not designed to create an interior compartment.
U.S. Pat. No. 5,138,728 to Aston, disclosed is an interior container insert for pillow, cushions or stuffed toy. The insert is constructed of flexible material and is removable. Once inserted it can be covered with an exterior casing to camouflage its presence. It is independent of any casing.
U.S. Pat. No. 4,688,286 to Miker, Jr., disclosed is a pillow having storage compartment pockets for personal items, wherein the pockets are hidden from view due to the fact that the pockets are placed on the bottom side of the pillow, as there is nothing unique in the structure of the pocket itself to keep it hidden from obvious view. Thus, if the pillow in Miker, Jr. were simply turned over all of the pockets would be totally exposed.
U.S. Pat. No. 3,863,283 to Mohr, disclosed is a pillow with interior storage compartment for first-aid equipment, intended to be stored in a vehicle.
U.S. Design Patent No. 482923 S to Gaines, disclosed is a pillowcase with a security pocket constructed on the exterior.
U.S. Patent No. 627638 to Connolly et al., disclosed is a pillowcase constructed with a flat pocket attached to the exterior for inserting and positioning a child's toy so that it is within sight of child.
U.S. Design Patent No. 346086 to Jones, disclosed is a pillow constructed with a pocket sewn to the exterior.
U.S. Pat. No. 4,185,673 to Daniello, disclosed is an article-carrying bag which doubles as a seat cushion when emptied of articles, preferably equipped with carrying handles.
U.S. Pat. No. 1,617,822 to O'Leary, disclosed is specifically a pillow which is constructed to form a compartment for receiving a receptacle that gives off an aroma such as medicinal preparation assisting in respiratory ailments.
U.S. Pat. No. 2,637,861 to Kethledge, disclosed is a pillowcase in which the object is to efficiently sustain the pillow tick against shifting or displacement.
U.S. Pat. No. 5,168,590 to O'Sullivan, disclosed is a therapeutic pillow cover having compartments, including a central depression region, for receiving hot/cold packs and/or pillow insert supports to adjust thickness, curvature and shape. Pockets are separate items that may or may not be attached.
U.S. Pat. No. 2,545,970 to Rand, disclosed is a pillow case with an opening for inserting a pillow and at the same end are a pair of pockets folded inward, then stitched for intended use of anchoring and concealing inserted pillow.
The present invention, unlike the above patents, is concerned with providing a simple, easily accessible open pocket positioned within the pillowcase and either against the side of a one-piece pillow, between two pillows, or within a central cavity formed partially into one end of the pillow.
This invention relates to improvements in the use of pillows and pillowcases by which a pillowcase of any size, shape or configuration having one or more sleeves or extensions which becomes an obscured compartment when turned inward and tucked (1) between the inside of the pillowcase and against the outside of an inserted pillow of any size, shape or configuration, or (2) inside a single pillow of any size, shape or configuration and having a central cavity extending into the pillow from one end thereof that is inserted into the pillowcase, or (3) between two or more pillows of any size, shape or configuration, that are simultaneously inserted into the pillowcase, creates one or more hidden compartments used to hide or store items such as text notes, greeting cards, photographs, and soft sculptures.
With the use of this pillowcase, any pillow(s) can be converted into one with a hidden compartment(s). Some of the advantages of the invention lie in the simplicity of construction and versatility of use with one or more pillows including those of standard shape, size and thickness as well as those of a variety of shapes, sizes and thickness.
There is easy access to the inner compartment of the pillowcase, although the opening(s) may be hidden from normal viewing. The obscured compartment(s) can remain open in the sense that it is not temporarily fastened by means such as a zipper, snaps, a Velcro-type product, and the like, however it can be fastened by such means. The exterior of pillowcase can be of normal appearance and upon further investigation an opening(s) to an inner compartment(s) can be discovered.


A surgical instrument support arm of a teleoperated patient side cart may include a first arm portion including a first connector end and a second a second arm portion including a second connector end. The second arm portion may be removably connectable to the first arm portion via mating engagement of the first and second connector ends. The first and second connector ends may each include complementary mechanical connections and complementary electrical connections. At least one of the electrical connections of the first and second connector ends may include electrical shielding to protect against electrical interference in a position in which the electrical connections are matingly engaged. The electrical shielding may be configured to axially compress when the electrical connections of the first and second connector ends are matingly engaged.

Teleoperated surgical systems (sometimes referred to as "robotic surgical systems") may be used to perform minimally invasive medical procedures, with the surgical system actuating a surgical instrument according to commands provided by a user. Maintenance programs may be performed upon the surgical system, such as to repair, replace, or clean parts of the surgical system. To facilitate maintenance, one or more parts of the surgical system may be removable for repair, cleaning, or even replacement (temporary or otherwise). To minimize or eliminate downtime of the surgical system, it may be desirable to have those parts be field replaceable so the part can be removed in the field without having to take the entire system out of use. In the case of patient side cart manipulator arms of teleoperated surgical systems, there exists a continued need to improve upon the field replaceability of such parts, making replacement relatively easy by a user in the field and robust.

Manipulator arm having connection interface, and related devices and systems


A method for making a reinforcing structure for a vehicle tire includes laying down at least one continuous thread element onto a support element, generating one or more layers. A path of the at least one thread element is substantially concentric with a rotation axis of the tire. The at least one thread element is laid down according to an undulated trajectory including a plurality of waves succeeding each other along a line circumferentially extended around the rotation axis of the tire. A tire for a vehicle wheel includes a carcass structure, a pair of annular anchoring structures, reinforcing structures disposed at axially opposite side portions of at least one carcass ply of the carcass structure, a belt structure, a pair of sidewalls, and a tread band. Each reinforcing structure includes one or more layers of at least one continuous thread element extending according to the undulated trajectory.

1. Field of the Invention
The present invention relates to a method for making reinforcing structures for vehicle tyres, comprising the step of laying down at least one continuous thread-like element onto a support element, according to a deposition path substantially concentric with the rotation axis of the tyre.
The invention also relates to a tyre integrating reinforcing structures made according to said method, said tyre being of the type comprising a carcass structure including at least one carcass ply having its ends in engagement with respective circumferentially inextensible annular anchoring structures; said carcass ply having two axially-opposite side portions separated from each other by a crown portion and each extending radially away from one of the annular anchoring structures until said crown portion; a belt structure applied to said crown portion at a radially external position relative to the carcass ply; a pair of sidewalls applied to said side portions at an axially external position relative to the surfaces of the carcass ply; a tread band applied to the belt structure at a radially external position thereof; reinforcing structures, each comprising at least one continuous thread-like element extending in an undulated trajectory substantially concentric with the rotation axis of the tyre.
2. Description of the Related Art
Manufacture of tyres for vehicle wheels involves formation of a carcass structure essentially made up of one or more carcass plies shaped in a substantially toroidal configuration and having their axially opposite side edges in engagement with respective annular anchoring structures integrating circumferentially inextensible annular inserts usually referred to as "bead rings" placed at the tyre regions usually identified with the name of "beads".
Applied to the carcass structure, at a radially external position, is a belt structure comprising one or more belt layers in the form of a closed loop, substantially made up of textile or metallic cords suitably oriented with respect to each other and to the cords belonging to the adjacent carcass plies.
At a radially external position to the belt structure a tread band is applied usually comprising a strip of elastomeric material of appropriate thickness.
It should be pointed out that, to the aims of the present description, by the term "elastomeric material" it is intended blends of rubber in their entirety, i.e. assemblies formed of at least one base polymer suitably amalgamated with reinforcing fillers and process additives of various types.
Finally, to the opposite sides of the tyre being processed, a pair of sidewalls is applied each of which covers a side portion of the tyre included between a so-called shoulder region, located close to the respective side edge of the tread band, and a so-called bead located at the corresponding bead-ring.
Tyres are generally classified into at least two categories, differentiated from each other due to the orientation exhibited by the cords being part of the carcass plies. In particular, there are the so-called "radial tyres" in which each of the cords arranged in the carcass ply or plies lies in a plane substantially radial to the rotation axis of the tyre, i.e. has an orientation substantially orthogonal to the circumferential extension direction. Then there are the so-called tyres "of the conventional type" or "cross-ply tyres", the carcass structure of which generally comprises at least one carcass ply having cords oriented obliquely to the circumferential extension direction of the tyre, and a second carcass ply, radially superposed on said first ply, the cords of which exhibit a symmetrically-crossed oblique orientation with respect to the cords of the first ply.
Tyres of the radial type, as compared with those of the conventional type, offer advantages in terms of lightness, ride comfort, resistance to wear and structural strength to high speeds. Conversely, they have a sidewall of weaker structure than tyres of the conventional type, so that a possible failure at the sidewall usually involves the tyre being out of use.
The above features have caused the tyres of the conventional type to be basically fallen into disuse in those Countries where a modern road network (minimising the risk of accidental failures to the sidewall) is present, in favour of tyres of the radial type.
Development in time of these tyres has led to a progressive reduction in their section height also for the purpose of obviating the feeling of ride unsteadiness generated by the sidewalls that are radially very extended.
In particular cases and/or for specific uses requiring that the tyre sidewalls should have a higher strength than that offered by the carcass ply, also in combination with a reduced section height, the sidewalls of a tyre is to be strengthened by means of additional reinforcing elements.
In particular, from document U.S. Pat. No. 3,044,522 reinforcement for tyres is known which is assembled on a collapsible drum and subsequently applied to the tyre carcass. The reinforcement is made up of layers axially disposed in a side-by-side relationship upon interposition of an elastomeric filling element. Each layer is defined by a plurality of coils disposed radially in side-by-side relationship and extending in a sinuous course having predetermined pitch and width. In addition, the coils of two distinct layers are circumferentially offset relative to each other, by about half a pitch.
Document U.S. Pat. No. 3,044,522 in the same manner as many other traditional production methods, essentially involves that the individual tyre components should be first made separately from each other to be then assembled during a tyre-building step.
The Applicant's present trend is however that of resorting to manufacture methodologies enabling production and storage of semi-finished articles to be minimised or, if possible, eliminated.
Practically, the research and development studies carried out by the Applicant are oriented to new process solutions allowing the individual components to be made by directly forming them on the tyre being built, preferably following a pre-established sequence.
This is particularly suitable above all in the production of tyres of the radial type.
In this connection, production processes have been proposed which aim at obtaining given tyre components, such, for example, as tread band, sidewalls or others, by laying down onto a toroidal support carrying the tyre being worked, a continuous strip-like element of elastomeric material having a reduced section as compared with that of the component to be obtained and disposed to form a plurality of coils around the rotation axis of the tyre, which coils are arranged consecutively in side by side relationship and/or superposed on each other so as to define the component itself in its final configuration.
In the European Patent Application No. 01830350.3 the Applicant has proposed adoption of annular stiffening inserts placed at the sidewalls of the radial tyres to increase stiffness of same, obtained by circumferentially winding at least one continuous thread-like element into several consecutive turns so as to form a series of coils disposed in radial side by side relationship and concentric with the geometric rotation axis of the tyre.
The Applicant has perceived that, notwithstanding the good results achieved with these inserts formed of one or more spiral-wound thread-like elements, there is still an interest in trying to improve tyre performance, in particular as regards increase in the sidewall stiffness of tyres intended for equipping two-wheeled vehicles. In fact, during the ride on a bend these tyres bank with respect to the vertical, according to camber angles of a very high value, thereby submitting the tyre sidewalls to important stresses.
These tyres have a marked transverse curvature at the crown which is normally defined by the particular value of the ratio between the distance of the tread centre from the line passing through the laterally opposite extremities of the tread itself, measured at the equatorial plane of the tyre, and the distance measured along the tyre chord between said extremities. In tyres for two-wheeled vehicles the value of the curvature ratio is generally at least about 0.15 and usually it is of about 0.3 in the case of rear tyres and also higher, until about 0.45, in the case of front tyres, versus a value usually of about 0.05 in motor-vehicle tyres.

Method for making a reinforcing structure for a vehicle tyre and a tyre made by the method


In analog color television transmission methods, the transmitted CVBS signal comprises luminance and chrominance signals which have to be separated from one another in a television receiver in order to permit separate further processing. Comb filters can be used for this, a picture contents-dependent controller frequently being worked with which switches over between different filter algorithms, that is to say different line combinations, as a function of the respective chrominance signals. In the case of conventional comb signals, the CVBS signal is split into the luminance signal and a chrominance signal which is still to be demodulated into the two color difference signals. In this case, the identification of color edges, in particular, is not always carried out in a manner free from errors. This can lead to only incomplete separation of the luminance and chrominance signals, so that cross effects cannot fully be avoided. Better detection of color edges and hence improved separation of the luminance and chrominance signals can be achieved if the structure of the luminance signal is also investigated for the selection of the filter algorithm. According to the invention, therefore, two color component signals (U*, V*) are demodulated from the CVBS signal, which color component signals are evaluated together with the CVBS signal in order to determine an optimum line combination (CF2) and, corresponding to this combination, permit improved generation of the luminance signal (Y) and of the color difference signals (U, V).

1. Field of the Invention
The invention relates to a method and to a circuit arrangement for separating luminance and chrominance signals of a CVBS signal, in particular a comb filter arrangement for PAL signals.
2. Prior Art
In analog colour television transmission methods, the transmitted CVBS signal comprises luminance and chrominance signals. In the case of PAL and NTSC, the chrominance signal, for its part, is composed of two colour difference signals (U/V signals in the case of PAL, I/Q signals in the case of NTSC) which are modulated in quadrature phase onto a colour subcarrier.
In a television receiver, the luminance and chrominance signals must be separated from one another again in order to permit separate further processing. For this, comb filters are used which carry out a combination of a plurality of adjacent lines on the basis of line, field and frame delays for the purpose of signal separation. It is customary here to work with a picture contents-dependent controller which, depending on how the chrominance signals are structured, switches over between different filter algorithms.
In the case of conventional comb filters which split the CVBS signal into the luminance signal and the chrominance signal, which comprises the two colour difference signals still to be demodulated, the identification of colour edges, in particular, is not always carried out in a manner free from errors. This can lead to incomplete separation of the luminance and chrominance signals, so that it is frequently the case that cross effects cannot fully be avoided.

Method and circuit arrangement for separating luminance and chrominance signals of a CVBS signal


A method for processing biopolymer arrays and apparatus and computer program products for executing the method. The method may include reading a different array identifier for each biopolymer array from a tag associated with that array. At least some of the biopolymer arrays are read and results from each read array saved in a memory linked with the read identifier for that array. Different communication addresses and a selection of an array identifier for each, are received. For at least some of the arrays, the saved results for each are matched with one of the different communication addresses using the identifier, and the saved results transmitted for those arrays to the matched different communication addresses. A method of processing data from the reading of biopolymer arrays is also provided.

Biopolymer arrays such as polynucleotide arrays (for example, DNA or RNA arrays), are known and are used, for example, as diagnostic or screening tools. Such arrays include regions of usually different sequence polynucleotides arranged in a predetermined configuration on a substrate. These regions (sometimes referenced as "features") are positioned at respective locations ("addresses") on the substrate. The arrays, when exposed to a sample, will exhibit an observed binding pattern. This binding pattern can be detected upon interrogating the array. For example all polynucleotide targets (for example, DNA) in the sample can be labeled with a suitable label (such as a fluorescent compound), and the fluorescence pattern on the array accurately observed following exposure to the sample. Assuming that the different sequence polynucleotides were correctly deposited in accordance with the predetermined configuration, then the observed binding pattern will be indicative of the presence and/or concentration of one or more polynucleotide components of the sample.
Biopolymer arrays can be fabricated by depositing previously obtained biopolymers onto a substrate, or by in situ synthesis methods. The in situ fabrication methods include those described in U.S. Pat. No. 5,449,754 for synthesizing peptide arrays, and in U.S. Pat. No. 6,180,351 and WO 98/41531 and the references cited therein for synthesizing polynucleotide arrays. Further details of fabricating biopolymer arrays are described in U.S. Pat. No. 6,242,266, U.S. Pat. No. 6,232,072, U.S. Pat. No. 6,180,351, and U.S. Pat. No. 6,171,797. Other techniques for fabricating biopolymer arrays include known light directed synthesis techniques.
In array fabrication, the probes formed at each feature is usually are expensive. Additionally, sample quantities available for testing are usually also very small and it is therefore desirable to simultaneously test the same sample against a large number of different probes on an array. These conditions make it desirable to produce arrays with large numbers of very small (for example, in the range of tens or one or two hundred microns), closely spaced features (for example many thousands of features). After the arrays are exposed to a sample and read, the array reading apparatus must be able to read such arrays with a very fine resolution (for example, in the range of five to twenty microns). This requires an array reader which may be expensive and which may take some time to read each array. On the other hand, many users will not need to occupy such a reader full-time. Thus, to reduce per user costs many different users may send their arrays for reading to a same array reader. The read results for the users different arrays can be sent to a common computer to which each user may visit and retrieve the results for their array.
The present invention recognizes that it would be desirable to provide different users who use a common biopolymer array reader, with a convenient and easy to use way of obtaining the read results for their arrays or status of the reading of their arrays.


A lamp for a vehicle includes a light generation unit with an array module having a plurality of micro Light Emitting Diode (micro-LED) elements. The lamp also includes at least one processor and a computer-readable medium having stored thereon instructions that, when executed, cause the at least one processor to: control the light generation unit to form a light distribution pattern that, when projected on a vertical plane at a first distance, has a luminous intensity that is progressively smaller from a central point closer to a center towards a peripheral point further from the center. Controlling the light generation unit to form the light distribution pattern includes: controlling at least one first micro-LED element to generate a first luminous intensity at the central point, and controlling at least one second micro-LED element to generate a second luminous intensity at the peripheral point.

A vehicle is an apparatus that moves in a direction desired by a user riding therein. A representative example of a vehicle is an automobile.
A vehicle typically includes various lamps. For example, a vehicle typically includes a head lamp for illuminating a forward area of the vehicle, a rear combination lamp, and a fog lamp.
Such lamps for a vehicle may be classified as lamps for facilitating visibility for a driver (e.g., a head lamp and a fog lamp), and lamps for notifying a simple signal (e.g., a rear combination lamp).


A method executed by a processing system of an edge router deployed in a content distribution network includes receiving a request from an endpoint device for a first file, determining that a portion of the first file is not stored in a cache of the edge router, determining that the cache is at a capacity threshold, selecting a second file to evict from the cache, wherein the second file is one of a plurality of files stored in the cache, wherein each file of the plurality of files is scheduled to be evicted from the cache when a threshold period of time has passed since a last request for the each file was received by the edge router, and wherein the threshold period of time associated with the second file is scheduled to expire soonest among all of the plurality of files, and evicting the second file from the cache.

Over-the-top (OTT) streaming systems distribute multimedia content directly to users over the Internet, e.g., without the aid of platforms that have traditionally been used to distribute multimedia content (e.g., broadcast television, telecommunications, and the like). For instance, a video on demand (VOD) service provider may stream video content (e.g., movies, television shows, and the like) to subscribers over the Internet. The subscribers may view the video content on smart televisions, televisions equipped with digital media players, personal computers, mobile devices, gaming consoles, and other devices that are capable of connecting to the Internet.

Minimizing stall duration tail probability in over-the-top streaming systems


A cascaded integrator-comb (CIC) interpolation filter is included within a digital-to-analog converter (138) and includes two up-samplers (150, 164). The two up-samplers (150, 164) also include a sample-and-hold function. The first up-sampler (150) up-samples an output of a differentiator (140). The second up-sampler (164) up-samples an output of an integrator (152) This reduces the area and power requirements of the CIC interpolation filter, while providing approximately the same filtering performance in the pass band and transition band. The total over-sample ratio of the CIC interpolation filter is equal to the first up-sampling ratio multiplied by the second up-sampling ratio. The stop band requirements of the CIC interpolation filter determines the relative sizes of the first and second up-sampling ratios.

The design of a sigma delta digital-to-analog (D/A) converter requires an interpolating filter that reduces the images of the signal at the input of the digital modulator. A cascaded integrator-comb (CIC) interpolating filter is a type of digital linear phase finite impulse response (FIR) filter which can be used in a sigma delta D/A converter to perform filtering and interpolating functions. In contrast to a CIC decimation filter of a sigma delta analog-to-digital (A/D) converter, the digital filtering requirements of the sigma delta D/A converter may be governed more by the system's power spectral density specification than by the need to filter quantization noise. Cascaded CIC interpolation filters are often used to perform this interpolating/filtering function because they are simple and economical (no multipliers are required). As the interpolating rate increases, however, the CIC filter digital word width grows rapidly.
FIG. 1 illustrates, in partial block diagram form and partial logic diagram form, a D/A converter 99 having a CIC interpolation filter in accordance with the prior art. D/A converter 99 includes a differentiator 100, an up-sampler 114, an integrator 116, a scalar 130, and a sigma delta D/A converter 132. The CIC interpolation filter portion of D/A converter 99 includes differentiator 100, up-sampler 114, and integrator 116. Differentiator 100 is a fourth order differentiator and includes stages 102, 108, 110, and 112. Stage 102 includes delay element 106 and adder 104. The other differentiator stages are substantially the same as stage 102. Differentiator stage 102 is a conventional differentiator which subtracts a delayed version of a digital word labeled "DIGITAL INPUT" from the DIGITAL INPUT and provides a difference output to the next stage of differentiator 100. The number of output bits between each of the stages increases because the digital word width is growing after each differentiation. The increased width of each subsequent differentiator stage is necessary to avoid overflow and retain accuracy during the differentiation. The output of differentiator 100 is provided to an input of up-sampler 114. Up-sampler 114 up-samples the sample frequency (f.sub.s) at a rate labeled "R" and provides an output to the input of integrator 116 having a frequency of R*f.sub.s.
The operation of D/A converter 99 can be better understood with reference to FIGS. 2-1 through 2-3. FIGS. 2-1 through 2-3 illustrate waveforms of various signals of prior art D/A converter 99 of FIG. 1. Note that f.sub.s is the sample frequency of differentiator 100. The variable R is the integer rate change factor and can be any number. Illustrated in FIG. 2-1 is the output of differentiator 100 labeled "A", and corresponds with the output of differentiator 100 illustrated in FIG. 1. The output of up-sampler 114 is labeled "B" and is illustrated in FIG. 2-2. The waveform B in FIG. 2--2 illustrates the frequency response of the output of up-sampler 114. The up-sampling operation causes the spectral energy from 0 to f.sub.s to replicate at intervals of f.sub.s to R times f.sub.s, where R is the up-sampling ratio. Because up-sampler 114 also includes a sample-and-hold circuit, the spectral images at intervals of f.sub.s are multiplied by a sin(x)/x function, where the zeros of the sin(x)/x function will occur at a multiple of the sample frequency f.sub.s. The number of bits entering up-sampler 114 is 20. FIG. 1 illustrates the case where R=200. If R equals 200, an 8 bit increase in the number of bits from the input of up sampler 114 to the input of integrator 116 is necessary.
Integrator 116 includes integrator stages 118, 124, 126, and 128. Stage 118 includes delay element 122 and adder 120. Each of the subsequent integrator stages are substantially the same as integrator state 118. As with differentiator 100, a number of bits need to be added from one stage to the next to avoid overflow and retain accuracy. By the time the output of integrator 116 is reached, a total of 47 bits are required, and are provided to an input of scalar 130. The 47 bit register and all of the registers from each of the previous stages are being clocked at a rate equal to R times frequency f.sub.s.
Scalar 130 is used to reduce the number of bits from integrator 116 to 16 bits. The output of scalar 130 is labeled "C" and is illustrated in FIG. 2-3. Scalar 130 is implemented as a 31 bit shift left in the illustrated embodiment. Sigma delta D/A converter 132 performs a conventional D/A conversion to provide an output labeled "ANALOG OUTPUT".
A problem with CIC interpolating filter 99 is that, by clocking the integrator 116 at a very high rate with a large number of bits, implementation problems occur because of the large number of bits required for each the adders for each integration stage. For example, for R=200, the adder of stage 128 must be 47 bits wide, the adder of stage 126 is 40 bits wide, the adder of stage 124 is 34 bits wide, and the adder of stage 118 is 28 bits wide. Also, operating these large adders at a high frequency consumes a large amount of power. In addition, implementing integrator 116 with large adders requires a relatively large surface area of an integrated circuit having CIC interpolating filter 99, which increases manufacturing costs and the size of the integrated circuit. In addition, when R=200, the frequency of the output of integrator 116 will be 200 times f.sub.s. Therefore, integrator 116 should be implemented in a very high speed process which can be very expensive to manufacture.

Cascaded integrator-comb interpolation filter


A complete closed-loop system of capture, analysis, and corrective feedback uses small unobtrusive, strategically placed sensors on the ear, hip, knee, wrist, and/or ankle that communicate wirelessly to a base unit. The sensors capture movement during an activity to be analyzed, such as a golf swing, and send data to a base unit, which processes and transmits the data to a smart phone or other suitable portable and wireless communications device. The wireless communications device, in turn, transmits the processed data to a data base in the cloud (centrally based Internet software) where software instantly analyzes the motion represented by the processed data, then provides immediate feedback for improvement to the user.

The invention is related to motion capture, analysis, display and professional feedback for the purpose of evaluating the body motion of a subject involved in an athletic training or medical monitoring exercise.
Certain tools exist today that allow users to capture motion and analyze the motion. The tools typically comprise video-based, wearable sensor-based or wireless sensor-based approaches. Current tools have a limitation due to available equipment and the need for interpretation of gathered data. In the case of video capture, the user must have a video camera equipment setup in the location where they wish to use the equipment. In the case of wearable sensors, the sensors provide positional data that must be analyzed by a professional to provide valuable feedback to the user. None of these systems either a) are portable or b) work without a professional instructor reviewing the results and recommending correction.

Motion capture and analysis systems for use in training athletes


A cutter knife including an upper cover, a lower cover engaged with the upper cover to form a handle, a knife holder force-fitted with a front end of the lower cover and having a slit and a threaded recess, a knife partly inserted into the knife holder through the slit of the knife holder, a knob threadedly engaged with the recess of the knife holder, and a tail seat engaged with a rear end of the handle and having a slit.

It has been found that the prior art cutter knife falls into two categories, i.e. the fixed type and the telescopic type. However, it is necessary to dismantle the handle of the fixed type cutter knife in order to replace the blade thereby making it inconvenient to use. Further, regarding the telescopic type cutter knife, the blade thereof will be forced into the handle when a relatively large force is applied thereto.
Therefore, it is an object of the present invention to provide an improved knife which may obviate and mitigate the above-mentioned drawbacks.


A process is disclosed for manufacturing a protective skin for resurfacing reusable beverage containers. First, the peripheral surface of a cylindrical beverage container is measured and recorded, the measurements being used as a template for forming the skin from the substrate. Second, a suitable thermoplastic substrate is chosen such as scratch resistant vinyl or LEXAN.RTM.. Third, a graphic image or product name can be back printed on the substrate. Fourth, an adhesive backing is applied to the printed side of the substrate. And fifth, the substrate is formed into the desired shape by an apparatus using the recorded measurements of the beverage container. The resulting chemical and abrasion resistant protective skin may then easily be applied by any consumer wishing to cover the peripheral surface of a reusable beverage container that may have become damaged through use or misuse or to apply custom graphics and/or a logo thereto.

Conventional reusable beverage containers or servers generally comprise a cylindrical type vessel that may or may not have graphic images on their exterior surface or shell. Large beverage containers especially commercial hot beverage servers generally have a stainless steel protective outer shell. The shell has a dual function: to provide a protective covering for the internal components of the container (or the shell may also contain the liquid) and to provide a surface that is visually pleasing.
Application of this shell usually occurs during the manufacturing process. Once applied, it cannot easily be replaced if damaged, nor has it been commercially feasible to reprint any graphic images on the surface of the shell if they have become faded or altered through use. In both of these situations, the functionality of the shell to shield the inner components (or to contain a liquid) is usually not compromised. Instead, it is the visual appearance of the shell that has become undesirable.
Metal shells are the traditional materials of choice. Metal shells are easily manufactured and integrated into the great variety of beverage containers and especially hot beverage servers. These shells provide adequate impact resistance, but when the metal deforms, it does not return to its original shape. Consequently, the aesthetic value of the shell, and hence the container, diminishes.
While the appearance of personal beverage containers is generally not an important factor in their usability, commercial settings create a need for visually appealing accessories. In commercial settings, the image and the ability of that image to convey a message are often just as important as the ability of the item to function properly. Consequently, when the visual image of a commercial container or server no longer conveys the intended message nor provides the intended function, the container is often cannibalized or a replacement container is obtained. While accomplishing the goals of the business, such a practice can be expensive and time consuming.
Therefore, a need exists to have a method for restoring the exterior surface or shell of a reusable beverage container or server whereby a new protective skin will enhance the container's ability to withstand everyday use without losing its aesthetic qualities. The need also exists to refurbish the exterior surface or shell such a container so that desirable graphic images or patterns can permanently be displayed without fear of degradation. Similarly, a need also exists to provide a method for permanently applying customizable graphic images to the exterior surface or shell of commercially produced, reusable beverage containers. In addition, a process and product meeting these needs must be inexpensive and easy to carry out--the application of the product preferably performed by the possessor of the container.

Process for manufacturing a protective skin for resurfacing reusable beverage containers


A disk device includes a disk tray, a spindle motor, a chucking section, a loading motor, a tray-in switch, a tray-out switch and a loading motor drive voltage generating section. The loading motor drive voltage generating section generates a drive voltage for the loading motor so that a torque of the loading motor is gradually increased after the tray-out switch detects that the disk tray is not located at a predetermined range between an eject position and a retract position until the tray-in switch detects that the disk tray is located at the retract position.

1. Field of the Invention
The present invention generally relates to a disk device. More specifically, the present invention relates to a disc device with which data recorded on a disk recording medium is reproduced.
2. Background Information
A conventional disk device records and reproduces CD's, DVD's, and other such optical disks. The disk device includes a disk tray and a loading mechanism. An optical disk is placed on the disk tray. The loading mechanism loads and unloads the disk tray to carry the optical disk. Loading refers to an operation of retracting the disk tray into the disk device. Unloading refers to an operation of extracting (or ejecting) the disk tray from the disk device. The disk device also includes a tray-in switch and a tray-out switch. The tray-in switch detects whether or not the disk tray is completely in a close position. The tray-out switch detects whether the disk tray is in an open position or in a loading/unloading state.
The disk device also includes a chucking pulley and a disk table. The chucking pulley is suspended from an upper part of a loading position of the optical disk. The disk table is raised to a chucking position and engaged from below in a center hole of the optical disk. Then, the optical disk is raised above the disk tray, at which point the optical disk is magnetically chucked on the disk table by the chucking pulley.
During the unloading of the disk device, first the disk table is lowered integrally with a spindle motor from the chucking position to the chucking release position (e.g., unchucking position) by one of the loading motors of the loading mechanism, which unchucks the optical disk. Specifically, the disk table is pulled downward and away against the magnetic chucking force of the chucking pulley, so that the optical disk is separated from above the disk table. Then, the optical disk is unloaded from the loading position to the unloading position by the disk tray.
A technique related to controlling the loading and unloading operations has been disclosed in Japanese Laid-Open Patent Application Publication No. 2000-306308. With the operations, a high drive voltage that is higher than a normal voltage is applied temporarily to the loading motor for a specific length of time until immediately after the start of unloading. Then, the normal voltage is applied to the loading motor until the unloading is complete. The loading motor is driven at a high torque only under high load during chucking.
With the operations discussed in Japanese Laid-Open Patent Application Publication No. 2000-306308, the system is controlled so that the high drive voltage is applied for the specific length of time to the loading motor only during the chucking operation carried out immediately after the start of unloading. However, a problem remains in that when the high drive voltage is suddenly applied during the chucking operation, the torque of the loading motor also increases, but so too does the operating noise of the loading motor.
In view of the above, it will be apparent to those skilled in the art from this disclosure that there exists a need for an improved disk device. This invention addresses this need in the art as well as other needs, which will become apparent to those skilled in the art from this disclosure.


A pilfer-proof cap made of synthetic resins capable of preventing at least a rotation of a packing together with a cap in a simple construction when said cap is removed and holding a sealed-up tightness of a container until a bridge is broken is provided.. A cap, in which a top wall and a skirt depending from said top wall are comprised and a threaded portion of the cap screwed in a threaded portion of the container is provided, a plurality of bridges, a packing provided so as to seal up tightly a mouth portion of container during the time when said cap is closed, a packing guide, a circular inner sealing member tightly insertable into an inner surface of said mouth portion of container provided in said packing and an air reservoir formed in an upper surface of the packing are comprised.

1. Field of the Invention
The present invention relates to a pilfer-proof cap made of synthetic resins to be put on a mouth portion of containers such as bottles for use in drinks.
2. Description of the Prior Art
A pilfer-proof cap having a container-sealing packing (hereinafter referred to as a packing), in which said packing is held at an appointed position on an inside surface of a top wall of a cap to be simultaneously lifted up together with said cap, whereby releasing a sealing for said container by the packing, when said cap is removed from said container, has been proposed (refer to Japanese Publication No. Sho 62-18421).
However, with such a construction, there has still been the possibility that the packing is lifted up together with the cap or is not removed from, but rather is rotated together with the cap to release said sealing for the container, whereby breaking an airtightness, while a bridge holding a band for mechanically engaging the cap with said mouth portion of the container is not broken, when a cap-opening action out of mischief and the like, so-called a slight rotation, is conducted while the cap is not fully removed.
The cap of this type is not preferably used in view of a protection for contents in the container in the case where a pressure within a tightly sealed-up container filled with contents is higher than that outside of said container (1), the case where said pressure within the tightly sealed-up container becomes equal to a pressure outside of the container and a packing is continuously adhered closely to a mouth portion of the container (2), or the case where it is used for tightly sealing up the container filled with a liquid heat treated at a high temperature or the container which is subjected to a high-temperature heat treatment after being filled with a liquid followed by being cooled to room temperature and, as a result, an inner pressure of the tightly sealed-up container is reduced and a packing is continuously adhered closely to a mouth portion of the container by a vacuum generated within the container (3). For example, in the case of the above described (1), a gas is leaked, and in cases of the above described (2), (3), the open air is apt to enter the container together with bacteria and, consequently, the contents of the container are apt to be denatured and corrupted in all of the above described cases (1), (2) and (3).

Pilfer-proof cap made of synthetic resin


A method for managing objects stored in a cache memory of a processing unit. The cache memory includes a set of entries corresponding to an object. The method includes: checking, for each entry of at least a subset of entries of the set of entries of the cache memory, whether an object corresponding to each entry includes one or more references to one or more other objects stored in the cache memory and storing the references; determining among the objects stored in the cache memory, which objects are not referenced by other objects, based on the stored references; marking entries as checked to distinguish entries corresponding to objects determined as being not referenced from other entries of the checked entries, and casting out, according to the marking, entries corresponding to objects determined as being not referenced.

1. Field of the Invention
This invention relates to memory management in computer systems and more particularly to garbage collection in a cache memory system.
2. Description of the Related Art
Modern dynamic and object-oriented languages use data structures that consist of small data objects referenced by pointers. The references to objects change quickly during the execution of a program, leaving objects with few or no references.
Garbage collection is a method to reuse memory that is occupied by data objects that are not referenced anymore. It is a form of automatic memory management. It is well known and has been improved over time. Garbage collection simplifies either the programming and/or enables algorithms that cannot keep track of object references efficiently. Garbage collection marks all objects that have a reference to it and reuses the memory that is occupied by all other objects. This assumes that the garbage collector can check all possible references. Hence, garbage collection allows data objects to be found in a program that cannot be accessed in the future, and reclaim the resources used by those objects.
The document U.S. Pat. No. 7,069,279 (B1) discloses a garbage collector for performing garbage collection that, from time to time, and within a single cycle, determines objects that are eligible to have their associated memory freed. The garbage collector relies on high-priority finalizers for determining eligible objects that are marked as ready for deallocation. The garbage collector, during a subsequent cycle, then deallocates the memory associated with marked objects.
The document U.S. Pat. No. 6,353,838 (B2) discloses an incremental garbage collector wherein, upon termination of a function or program, the incremental garbage collector scans the object heap for objects allocated by the function or program that are not referenced outside the function or program that allocated the objects. Memory occupied by such objects is immediately reclaimed without having to wait for the garbage collector.

International Business Machines Corporation