A cryocooler system comprising a heat exchanger for cooling a compressed returning warmed cryogenic fluid stream, the heat exchanger having a bypass loop to produce a major stream and a minor stream exiting the heat exchanger. The minor stream is further cooled by expansion and used as a heat exchange medium for an external heat load after which it is compressed and returned to the heat exchanger for heat exchange with the compressed return warmed cryogenic fluid stream. The major stream is further cooled by expansion and recirculated to the heat exchanger to cool the compressed returning warmed cryogenic fluid stream. The major stream and minor stream are combined either inside or outside of said heat exchanger to form the warmed cryogenic fluid inlet stream for compression.

This invention relates generally to refrigeration and more specifically to cryogenic refrigeration systems.
Cryogenic refrigerators, also known generally as cryocoolers, are needed to create refrigeration for superconductors, power transformers, magnetic resonance imaging, cryo surgery, and other cryogenic applications. There exist several known ways of supplying refrigeration at cryogenic temperatures.
One such technique involves the use of pulse tube refrigerators. U.S. Pat. No. 4,953,366 discloses an acoustic cryocooler formed from a thermoacoustic driver driving a pulse tube refrigerator through a standing wave tube. Pulse tubes, generally, are well known to those skilled in the art. A conventional pulse tube refrigerator uses a compression space, a radiator, an accumulator and a pulse tube arranged in series so as to constitute a closed operating space. Within the system there is a certain amount of operating fluid, such as helium gas, the pressure of which varies during operation of the device during compression and decompression. This varying pressure leads to the establishment of a phase difference between the pressure vibration and the displacement vibration of the operating fluid, which in turn leads to heat absorption at a lower temperature terminal.
The pulse tube refrigerator disclosed in the ""366 patent includes a pulse tube, a first heat exchanger adjacent the pulse tube for inputting heat from a thermal load for cooling, and a second heat exchanger for removing heat transferred from the first heat exchanger across the pulse tube. Typically, the advantage to a pulse tube refrigerator is its lack of moving parts. Disadvantages include, however, relatively limited power and high specific power required to generate the (limited) refrigeration.
Additional known patents which cover variations of the pulse tube refrigerator include U.S. Pat. No. 5,275,002 to Inoue et al., U.S. Pat. No. 5,689,959 to Yatsuzuka et al., U.S. Pat. No. 5,711,156 to Matsui et al., U.S. Pat. No. 5,904,046 to Kawano, U.S. Pat. No. 5,966,942 to Mitchell, and U.S. Pat. No. 6,094,921 to Zhu et al.
A second known refrigeration device is commonly known as a Stirling machine and there are known variants related thereto. These too are generally well known to those skilled in the art. U.S. Pat. No. 4,143,520 to Zimmerman discloses, for example, a split Stirling machine. The split Stirling machine includes a displacer which fits loosely in a cylinder, with the cylinder connected to a piston chamber in which a piston is placed. The displacer interacts mechanically with the piston. When the displacer is in its lowest position, the piston is moved to its extreme compression position where it compresses the working fluid (typically helium gas) which thereby generates heat. As the displacer is then moved to the top of its cylinder, the warmed fluid in the displacer cylinder moves from the top of the cylinder to the bottom, with the bottom of the cylinder being at a lower temperature before the warmed fluid passes into this lower region of the displacement cylinder. After the warmed fluid moves into the lower region of the displacement cylinder, the piston is them moved to its extreme decompressed position, cooling the working fluid within the system. Then, when the displacer is moved back to its lowest position again, the cooled fluid is moved back to the top of the displacement cylinder, thereby completing the cycle.
Other patents known which purport to take advantage of the Stirling machine include U.S. Pat. No. 5,022,229 to Vitale, U.S. Pat. No. 5,477,686 to Minas, and U.S. Pat. No. 5,333,460 to Lewis et al. Generally, these devices create more refrigeration at a reasonable specific power, but have more moving parts as compared to the pulse tube refrigerators discussed above.
Some attempts have been made to join the pulse tube refrigerator technology with the Stirling cycle. U.S. Pat. No. 6,167,707 to Price et al. discloses a hybrid two stage expander having a first stage pulse tube expander. A common reciprocating compressor pneumatically drives both stages. The first stage Stirling expander purportedly provides high thermodynamic efficiency that removes a majority of the heat load from a gas within the cryocooler. The second stage pulse tube expander provides additional refrigeration capacity. The use of this system has the combined on drawbacks discussed above individually for each type of cryocooler.
Another group of cryocoolers has been developed specifically to cool superconductive magnets. These include baths in fluid cryogens, systems involving compression and expansion, cryogens with rare earth displacement materials used in regenerators, apparatuses to recondense vaporized helium, and hybrid systems. Several U.S. patents have issued in this area, including: U.S. Pat. Nos. 4,782,671; 4,926,646; 5,396,206; 5,442,928; 5,461,873; 5,485,730; 5,613,367; 5,623,240; 5,701,744; 5,782,095; and 5,848,532.
Still other known systems are based on magneto caloric effect, such as U.S. Pat. No. 4,599,866, or cyclically concentrating and diluting the amount of isotope 3He in a 3Hexe2x80x944He solution, such as that disclosed in U.S. Pat. No. 5,172,554.
Moreover, the prior art, although addressing the need for cryocooling, has not solved the problem of achieving a more efficient cryocooler which provides high levels of refrigeration at relatively low cost.
The present invention is a refrigeration method and apparatus for supplying refrigeration to a heat exchanger whereby refrigeration can be transferred from the heat exchanger to an external heat load such as the coil of a superconducting magnet or transformer.
Therefore, one aspect of the present invention is an apparatus for supplying refrigeration to an external heat source comprising, in combination, a first compressor for compressing a returning warmed cryogenic fluid stream to form a compressed stream; a heat exchanger for receiving and cooling the compressed stream by heat exchange with a returning stream used to form the returning warmed cryogenic fluid stream; means in the heat exchanger to separate the compressed stream into a major stream exiting the heat exchanger and a minor stream exiting the heat exchanger; an expander for expanding the major stream together with means to return an expanded major stream to the heat exchanger; means to expand the minor stream exiting the heat exchanger to further cool the minor stream; heat exchange means to use the minor stream to provide refrigeration to an external heat load; means to compress the minor stream after heat exchange with the external heat load and return the minor stream to the heat exchanger; and means to combine the major stream and the minor stream to form the returning warmed cryogenic fluid stream.
According to one preferred embodiment of the present invention, the heat exchange means used to provide refrigeration to the external heat load is a vacuum refrigerator which allows thermal contact between the working fluid of the refrigeration cycle and the external heat source. Alternatively, the working fluid in the refrigeration cycle can be the same fluid as that contained in a bath used to cool an external heat source. In this later embodiment, the cooling cycle is the same as described above but involves the reliquefaction of the vaporized coolant. The coolant, in this embodiment, absorbs heat as a liquid, is vaporized, is run through the cycle to be reliquefied, and is then returned to the cooling bath as a cold liquid.
Another aspect of the present invention is a method of supplying refrigeration to an external heat source comprising the steps of compressing a warmed return cryogenic fluid stream to form a compressed refrigerant stream; passing the compressed refrigerant stream into a heat exchanger for cooling by heat exchange with returning refrigerant; dividing the refrigerant stream into a major stream and a minor stream as it passes through the heat exchanger; taking the major stream from the heat exchanger and expanding the major stream to further cool the major stream prior to using the major stream as a heat exchange fluid for cooling the compressed refrigerant stream, taking the minor stream and expanding it to further cool the minor stream and using the minor stream to provide refrigeration to the heat load; and thereafter compressing the minor stream; and combining the compressed minor stream and the major stream at one of, before, during or after using the major stream and the minor stream in the heat exchanger to cool the compressed refrigerant stream, the combined major and minor streams after heat exchange forming the warmed return cryogenic fluid stream.

Method and system for cryogenic refrigeration


A diode bridge has a pair of input ends to which an alternating current is inputted from an AC power supply, and a pair of output ends which output a direct current. A boost chopper circuit is connected to the pair of output ends, and sets up a DC voltage inputted thereto. The boost chopper circuit functions as a power factor correction circuit. A smoothing capacitor is connected to an output side of the boost chopper circuit, and smoothes the voltage across the smoothing capacitor. An inverter receives the voltage across the smoothing capacitor to apply AC power to a load. A leakage current reduction device outputs a compensating current which compensates for a leakage current leaking from the load. The leakage current reduction device outputs the compensating current, except near the zero crossing of an AC voltage inputted from the AC power supply.

Techniques for reducing a leakage current from a load have hitherto been proposed. For example, Japanese Patent No. 3044650 and Japanese Patent Application Laid-Open No. 11-122910 (1999) to be described below disclose techniques such that a compensating current supply circuit connected across a smoothing capacitor outputs a current which compensates for a leakage current from a load.
In a structure provided with no smoothing capacitor in Japanese Patent Application Laid-Open No. 2000-92861, a noise reduction circuit is provided between positive and negative input lines providing a connection between a diode bridge serving as a full-wave rectifier circuit and an inverter device. The noise reduction circuit has two transistors which perform the operation of turning on and off.
On the other hand, there are cases where a technique employing a power factor correction circuit is employed as a configuration of a power conversion circuit. In general, the power factor correction circuit is implemented by a boost chopper circuit. For example, when an object that the power conversion circuit drives is an electric motor and the electric motor drives a compressor which compresses a refrigerant for use in an air conditioner, the boost chopper circuit is used from the viewpoint of improving a heating capability at low temperatures.
The boost chopper circuit functionally has a reactor, a switch and a diode. The reactor is provided on the opposite side of the switch from a smoothing circuit.

Power conversion circuit with leakage current compensation except near the AC voltage zero crossing


A highly safe and inexpensive bone repair material that stably exhibits high antibacterial activity for a long time in a living body by supporting a large amount of an iodine ion and is excellent in apatite forming ability and preservability. The material includes a substrate made of titanium or titanium alloy and a titanate film on a surface of the substrate, the film composed of a large number of crystalline masses having a crystal structure and containing a calcium ion and an iodine ion, wherein the mass contains layers having a Ti—O skeleton and the calcium and the iodine ions adsorbed between the layers.

Titanium or titanium alloy has high fracture toughness and is biocompatible, and hence is widely used as a bone repair material for a portion where a large load is applied such as an artificial joint or an artificial vertebral body. In order to impart osteoconnectivity to titanium or titanium alloy, various methods for forming an apatite layer on a surface of a substrate made of titanium or titanium alloy have been examined. Among these methods, a bone repair material containing titanium or alloy thereof having, on its surface, a titanate layer or a titanium oxide layer with apatite forming ability forms apatite in a living body, and hence is said to be excellent in that the thus formed apatite is not cracked by dryness or thermal expansion difference from a substrate (Patent Document 1&2).
On the other hand, when an infectious disease is caused after embedding a bone repair material in the living body, it is difficult to treat the disease with an antibiotic. Therefore, various techniques for imparting antibacterial activity to a bone repair material have been proposed. For example, since silver has been known as an element exhibiting remarkably high antibacterial activity from a long time ago, a technique for replacing an alkali component contained in a titanate layer with a silver ion (Patent Document 3), and a technique for forming a coating film of a mixture of calcium phosphate and silver oxide on a surface of a titanium substrate (Patent Document 4) have been published. When silver is introduced into a bone repair material in the form of a metal particle, it is apprehended that the silver particle falls off from the surface of the material to accumulate in an unexpected organ to cause cytotoxicity, and hence, silver is introduced in the form of an ion or an oxide. A pharmaceutical containing a silver fine particle was once approved by US Department of Health and Human Services (FDA), but is currently prohibited because a high intake of such a pharmaceutical causes argyria. Besides, since it has been reported that iodine exhibits antibacterial activity as high as that of silver against MRSA and E. coli (Non-Patent Document 1), a technique for causing iodine to be contained in a micropore formed in a metal surface by electrodeposition has also been published (Patent Document 5).

Iodine-loaded bone repair material and method for producing the same


Biocompatible titanium base alloys for medical devices which are intended to remain on or in a living human being for an extended period of time, such as surgical and medical implants. The alloys are free from toxic elements such as Al, Ni, Co, Fe, Cr, Mo, and W. They are quaternary alloys of Ti with between about 2.5% up to 13% Zr, about 20% to about 40% Nb, about 4.5% to about 25% Ta, all percentages being by weight, the balance being Ti and the total of Ta plus Nb being between about 35% and 52% by weight. The ration of Nb/Ta is between 2 and 13. These alloys may also contain limited amounts of non-toxic interstitial elements, such as C, N, and O. The relative proportions of Ti, Zr, Ta, and Nb are such that the modulus of elasticity is below 65 GPa.

Biocompatible titanium base alloys are described in a number of United States patents including the following:
______________________________________ Steinemann et al 4,040,129 issued August 09, 1973 Wang et al 4,857,269 issued August 18, 1989 Wang et al 4,952,236 issued August 28, 1990 and Davidson et al 5,169,597 issued December 02, 1992. ______________________________________
The disclosures of these patents are incorporated in this application as representing the state of the art to which this invention relates and for their descriptions of such prior art.
The present invention is an improvement over the alloys described in the above noted patents insofar as it provides novel fully biocompatible alloys with a low modulus of elasticity.
In the Steinemann et al patent the toxicity of various elements are discussed and alloys of titanium and/or zirconium containing 3 to 30% by weight of at least one member selected from the group consisting of Nb, Ta, Cr, Mo, and Al are described. Several .alpha.-.beta. alloys are described along with a number of alloys containing Al, Mo, and Cr. No quaternary alloys of Ti, Nb, Ta, and Zr are described. The presence of Al, Cr, or Mo is undesirable because of their toxicity when the alloys are utilized in medical devices, such as surgical implants. The alloys of the present invention do not contain any Al, Cr, or Mo.
The alloys described in the two Wang et al patents contain an amount up to 3% of at least one eutectoid beta stabilizer selected from the group consisting of Fe, Mn, Cr, Co, and Ni, each of which is orders of magnitude more toxic than Ti, Zr, Nb, or Ta. The alloys described in these patents possess a modulus of elasticity (E) of 66.9 to 100 GPa with most of the alloys exhibiting a modulus of elasticity between 75 and 100 GPa. Unlike the alloys of Wang et al, the alloys of the present invention do not contain any of the toxic eutectoid stabilizers required by Wang et al.
Two specific alloys are described in Davidson et al 5,169,597; namely, a Ti--13Zr--13Nb and a Ti--18Zr--6Nb alloy. These alloys exhibit a modulus less than 85 GPa, and desirably between 60 and 85 GPa. The alloys of the present invention differ from those in Davidson et al, by having lower Ti and Zr contents and a content of Ta plus Nb which results in low moduli of elasticity.

Low modulus biocompatible titanium base alloys for medical devices


A method of forming a dielectric film by an organic metal CVD method, comprising the step of supplying an organic metal compound into a treating container having a substrate to be treated held therein to form the dielectric film on the substrate, wherein the dielectric film forming step comprises the first step of depositing, in the treating container, the dielectric film under a first condition so set as to allow the residence time of the organic metal compound to extend to a first value, and the second step of further depositing, after the first step and in the treating container, the dielectric film under a second condition so set as to allow the residence time of the organic metal compound to extend to a second value smaller than the first value.

A CVD technique is a film forming method that is widely employed in the process of manufacturing a semiconductor device.
In today's ultrahigh speed semiconductor devices, a gate length can be as short as 0.1 μm or less thanks to the advancement in the miniaturization technique. Generally, the operational speed of a semiconductor device improves with the miniaturization. However, the film thickness of a gate insulating film needs to be reduced in accordance with a scaling rule in such an extremely miniaturized semiconductor device because miniaturization inevitably requires a reduction in the gate length.
Similarly, the film thickness of a capacitor insulating film needs to be decreased to a few nanometers or less in order to secure a sufficient capacitance in a semiconductor device having a super miniaturized capacitor, e.g., DRAM.
Therefore, efforts have been made to find a method for forming a gate insulating film or a capacitor insulating film with a high-k dielectric material, e.g., HfO2 or ZrO2, which allows a reduction in the electrical film thickness while maintaining its large physical thickness to thereby avoid an increase in the tunneling current.
Conventionally, such a high-k dielectric film has been made through a MOCVD technique using a metal organic (MO) material which can be deposited at a low temperature, e.g., at a temperature not exceeding 600° C. (see Japanese Patent Laid-open Application No. H9-129626).
However, the high-k dielectric film formed through the MOCVD method has an average roughness Ra of a few Å exceeding, e.g., 0.3 nm in general. If such a high-k dielectric film is employed as the aforementioned gate insulting film in an ultrahigh speed transistor or as the capacitor insulting film in a super miniaturized DRAM, several problems may arise: namely, a tunneling leakage current path may form locally at a thin part of the film; a concentration of an electric field may occur due to an irregularity on the film surface; and the tunneling leakage current may increase in a local leakage current path.
For instance, in case of a HfO2 film formation in which tetra(tert-butoxy)hafnium is employed as a raw material, the average roughness Ra of the film is about 0.45 nm when the substrate is maintained at 550° C. and processed under a pressure of 0.3 Torr.
On the other hand, the average roughness Ra of a gate insulating film for MISFET is required to be smaller than or equal to 0.2 nm when the gate length thereof is 0.1 μm or less.


A structure of a flexible element has a force-receiving portion and a fixing portion, wherein the force-receiving portion is extended to have two arms for connecting with the fixing portion, so as to form two bending portions therebetween, characterized in that an inner end point is defined inside the fixing portion and the inner edges of the fixing portion are extended from the inner edges of the bending portion and intersected at the inner end point, so that a force-distributing section is defined between the bending portion and the inner end point, for distributing the torque applied on the bending portion, so as to eliminate the problem of too much concentrated stress.

Different kinds of switches are suitable for different types of electronic devices or electric appliances, wherein some switches equip flexible element to define a pressing stress or a recovering flexibility, and further, the flexible element can be used as an electrical conducting media, such as disclosed in U.S. Pat. No. 4,362,910, entitled "Electrical Switch". In this patent, the flexible element is used as the contacting element, and through pressing the flexible element, two electrical terminals in the electronic switch can be connected and conducted. Please refer to FIGS. 1A and 1B. The conventional flexible element 9 includes a force-receiving portion 91, and a fixing portion 93, wherein the force-receiving portion 91 has two arms 92 extended therefrom to define two bending portions 94 between the force-receiving portion 91 and the fixing portion 93, so that the conventional flexible element 9 has a bent shape. Furthermore, the fixing portion 93 is fixed on one electrical terminal of the switch through two fixing openings 931 thereof, so that when pressing the force-receiving portion 91, it will move down to contact the other electrical terminal. However, the force suffered by the force-receiving portion 91 will produce a torque to apply on the bending portion 94 through the arms 92 with a length of L, such that partial stress will concentrated on the intersections of the inner edges of the bending portion and the inner edges 932 of the fixing portion. As shown in FIG. 1B, F1, F2 and F3 represent the forces suffered by each region, wherein F1>F2>F3, and F1 is far larger than F2, so that the bending portion 94 is easy to have metal fatigue or be broken owing to an exceeded force. Therefore, the stress distribution of the conventional flexible element 9 is urgent to be improved for prolonging the life time of the flexible element.


A rapid exchange-type catheter for aspiration of embolic debris from a blood vessel includes an elongate aspiration tube and a relatively short guidewire tube mounted beside a distalmost portion of the aspiration tube. A proximal portion of the guidewire tube defines a strain relief segment. In one embodiment, the strain relief segment is formed detached from the aspiration tube. In another embodiment, the strain relief segment is minimally attached to the aspiration tube and becomes detached from the aspiration tube when a sufficient transverse force is applied to urge the guidewire tube away from the aspiration tube.

Human blood vessels often become occluded or completely blocked by plaque, thrombi, other deposits, emboli or other substances, which reduce the blood carrying capacity of the vessel. Should the blockage occur at a critical place in the circulatory system, serious and permanent injury, or even death, can occur. To prevent this, some form of medical intervention is usually performed when significant occlusion is detected.
A serious example of vascular occlusion is coronary artery disease, which is a common disorder in developed countries and is the leading cause of death in the United States. Damage to or malfunction of the heart is caused by narrowing or blockage of the coronary arteries that supply blood to the heart. The coronary arteries are first narrowed and may eventually be completely blocked by plaque (atherosclerosis), and the condition may further be complicated by the formation of thrombi (blood clots) on roughened surfaces of, or in eddy currents caused by the plaques. Myocardial infarction can result from coronary atherosclerosis, especially from an occlusive or near-occlusive thrombus overlying or adjacent to the atherosclerotic plaque, leading to ischemia and/or death of portions of the heart muscle. Thrombi and other particulates also can break away from arterial stenoses, and this debris can migrate downstream to cause distal embolization.
Various types of intervention techniques have been developed to facilitate the reduction or removal of a blockage in a blood vessel, allowing increased blood flow through the vessel. One technique for treating stenosis or occlusion of a blood vessel is balloon angioplasty wherein a balloon catheter is inserted into the narrowed or blocked area, and the balloon is inflated to expand the constricted area. Other types of interventions include atherectomy, deployment of stents, local infusion of specific medication, and bypass surgery. Each of these methods is not without the risk of embolism caused by the dislodgement of the blocking material, which may then move downstream.
Often, more than one interventional catheter is used during a procedure, such as to change the size of the balloon being used or to introduce additional devices into the system to aid with the procedure, including stent delivery catheters and aspiration catheters. In such situations, the catheters are generally inserted into the patient's cardiovascular system with the assistance of a guidewire. For example, a guidewire is introduced into the patient, steered through the tortuous pathways of the cardiovascular system, and positioned across an intended treatment location. Various catheters having a lumen adapted to receive the guidewire may then be introduced into and removed from the patient along the guidewire, thereby decreasing the time needed to complete a procedure.
Many techniques exist for preventing the release of thrombotic or embolic particles into the bloodstream during such a procedure. Common among these techniques is introduction of an occlusive device or a filter downstream of the treatment area to capture these embolic or thrombotic particles. The particles may then be removed from the vessel with the withdrawal of the occlusive or filtering device. In another common technique, the particles may be removed by an aspiration catheter prior to the withdrawal of these devices. Aspiration catheters have also been found useful in removing thrombus prior to crossing underlying atherosclerotic plaque with guidewires and/or treatment catheters. Such preliminary removal of thrombus makes it easier to cross the stenosis and less likely to release thrombo-embolic particles into the bloodstream during the procedure.
An aspiration catheter may be designed such that a guidewire is contained within the aspiration lumen as the catheter is advanced there over, or the aspiration catheter may include a dedicated guidewire lumen extending along substantially the entire length of the aspiration catheter such that the guidewire is disposed therein as the catheter is advanced through a body lumen. Such dual-lumen catheters having an aspiration lumen and a guidewire lumen may be constructed in a variety of ways including relatively simple profile extrusions, more complex assemblies of different tubular components, and combinations of these two methods.
Dual-lumen profile extrusions can have parallel round lumens surrounded by relatively uniform walls, resulting in a non-circular, generally figure-eight shaped transverse cross section. Alternatively, if a circular outer profile is desired, then dual-lumen profile extrusions can have parallel round lumens with non-uniform wall thicknesses or various other combinations of lumens having unequal sizes and non-round cross-sectional shapes such as D-shapes or crescent-shapes, as will be understood by one of skill in the field of cardiovascular catheters.
One of the important features of aspiration catheters is the ability to rapidly and efficiently aspirate even large embolic particles without the need to first break them into smaller sub-particles. This advantage is achieved, at least in part, by providing the catheter with an aspiration lumen having as large a cross sectional area as possible, given overall size constraints of the catheter design. In embodiments having an aspiration lumen that is crescent shaped or has another non-round shape, a relatively large cross-sectional area is preferably maintained to achieve rapid and efficient aspiration.
Aspiration catheters may also be of the so-called single operator or rapid exchange type. A rapid exchange aspiration catheter typically includes a tubular catheter shaft with an aspiration lumen extending the entire length thereof and a substantially shorter guidewire lumen extending along a distal portion of the catheter. As such, the guidewire is located outside of the aspiration catheter except for a short guidewire segment that extends within the guidewire lumen. Advantageously, a clinician is able to control both ends of the guidewire while the aspiration catheter is loaded or exchanged onto the guidewire, which may be already indwelling in the patient. The aspiration catheter is then advanced through the patient's vasculature with only a distal portion of the catheter riding on the guidewire.
Several types of aspiration catheters are disclosed in U.S. Patent Application Publication 2007/0106211 to Provost-Tine et al., which is incorporated by reference herein in its entirety. One of the aspiration catheters in the '211 publication is a rapid-exchange configuration, illustrated as FIG. 1 of the present application. FIG. 1 illustrates an aspiration catheter 20 suited for use in the treatment and removal of occlusions in blood vessels. Catheter 20 has a fitting 27 mounted at the proximal end in fluid communication with a proximal aspiration port 23. Catheter 20 includes an elongate tubular body 21 having a distal tip 26. Distal tip 26 can include a radiopaque marker (not shown) to aid in fluoroscopically locating tip 26 during insertion into the patient, and tip 26 is preferably soft to prevent damage to the patient's vasculature. Elongate tubular body 21 includes an aspiration tube 31 extending from fitting 27 to a location at or adjacent the distal end of tubular body 21. Aspiration tube 31 includes a tubular wall that defines an open aspiration lumen 12 (shown in FIG. 2), which extends the full length of tube 31. Aspiration lumen 12 fluidly connects aspiration port 23 disposed at or adjacent the proximal end of tubular body 21 with a distal fluid port 24 disposed at or adjacent the distal end of tubular body 21. A source (not shown) of partial vacuum or "negative pressure" may be connected to the luer adaptor of fitting 27 to aspirate blood and particulates through aspiration lumen 12 of catheter 20.
Catheter 20 further includes a dual lumen section 41 that is substantially shorter than the full length of catheter 20. Dual lumen section 41 includes a guidewire tube 51 that defines an open guidewire lumen 15 (shown in FIG. 2) sized and shaped to slidingly accept a medical guidewire therethrough. Guidewire tube 51 extends from an open proximal end 290 to an open distal end 29, alongside a distal portion of aspiration tube 31 such that aspiration lumen 12 and guidewire lumen 15 are in a parallel or side-by-side configuration. Dual lumen section 41 thus extends proximally from second fluid port 24 disposed at the distal end of aspiration tube 31 to open proximal end 290 of guidewire tube 51.
FIG. 2 is an enlarged cross-sectional view of open proximal end 290 of guidewire tube 51, showing a guidewire 50 extending through guidewire lumen 15. As shown in FIG. 2, open proximal end 290, which may also be referred to as a proximal guidewire port, of guidewire tube 51 is attached to the outer surface of aspiration tube 31. When the proximal guidewire port is attached to the catheter shaft in this manner, forces applied in a transverse direction to separate the guidewire from the catheter may cause the guidewire to tear the wall of guidewire tube 51, starting from open proximal end 290. There is therefore a need for an improved aspiration catheter that avoids the above-described problem of the guidewire tearing the guidewire shaft.

Rapid exchange catheter with tear resistant guidewire shaft


A successive approximation AD converter. A voltage comparator receives an analog input signal and a reference voltage. A successive approximation register receives the voltage comparator output, and a DA converter, connected to the successive approximation register, provides another analog signal to the voltage comparator. The voltage comparator includes differential amplifiers and an output amplifier connected in series via capacitance pairs, a first switch connecting the analog input signal to the first differential amplifier, a second switch connecting the first switch and the sampling capacitor to the reference voltage supply section, and a third switch connecting the first switch and the first differential amplifier to the reference voltage. When the input analog signal is sampled, the first switch is switched OFF, and the second and third switches are switched ON. When a voltage comparison is executed, the first switch is switched ON, and the second and third switches are switched OFF.

1. Field of the Invention
The present invention relates to an AD converter, and more particularly to a configuration of a voltage comparator having a sample hold which is used in a successive approximation AD converter.
2. Description of the Related Art
FIG. 2 shows the configuration of a conventional successive approximation AD converter. This AD converter is realized by a MOS integrated circuit, and comprises a voltage comparator 1, a successive approximation register 2, and a DA converter 3. The voltage comparator 1 has both a function for sampling an input analog signal and a function for performing a voltage comparison. The positive input terminal of the voltage comparator 1 is connected to a capacitor C1 serving as a sampling capacitor. An analog signal AIN to be subjected to AD conversion is input-into the positive input terminal of the voltage comparator 1 via a switch S1 and the capacitor C1. A connection point between the positive input terminal of the voltage comparator 1 and the capacitor C1 is biased to a reference voltage VR via a switch S6.
The negative input terminal of the voltage comparator 1 is connected to one end of a capacitor C2 and biased to the reference voltage VR via a switch S5. The other end of the capacitor C2 is biased to the reference voltage VR via switches S3, S4.
The successive approximation register 2 is connected to an output terminal of the voltage comparator 1, and holds an output signal from the voltage comparator 1. The DA converter 3 converts the data in the successive approximation register 2 into an analog signal. The output terminal of the DA converter 3 is connected to the positive input terminal of the voltage comparator 1 via a switch S2 and the capacitor C1.
The voltage comparator 1 used in the successive approximation AD converter described above is constituted as shown in FIG. 3, for example. Differential amplifiers 11, 12 and a final amplifier 13 are connected by multi-stage capacitive couplings. Switches S5 through S10 supplying the reference voltage VR are connected on each differential stage. The basic form of this circuit is disclosed in "Potential of MOS Technologies for Analog Integrated Circuits", IEEE Journal of Solid-State Circuits, Vol. SC-13, No. 3, June 1978, for example.
Further, the differential amplifiers 11, 12 used in the voltage comparator 1 are constituted as shown in FIG. 4, for example. A transistor 113 having a gate electrode serving as a positive input and a transistor 114 having a gate electrode serving as a negative input are connected in series respectively to transistors 111, 112 each having grounded gate electrodes, and the transistors 113, 114 are grounded via a bias transistor 115. The final amplifier 13 of the voltage comparator 1 has a configuration such as that shown in FIG. 5, for example, in which transistors 131 through 140 are wired.
Next, an operation of the conventional voltage comparator 1 shown in FIG. 3 will be described in reference to timing charts shown in FIGS. 8 and 9. The voltage comparator 1 performs an input signal sampling operation and a voltage comparing operation alternately. In FIG. 3, the symbol φ1 is annexed to switches that are ON when an input signal is sampled, and the symbol φ2 is annexed to switches that are ON when voltage comparison is performed. The timing chart of FIG. 8 shows a signal wave forms at points including the input of the comparator 1, the inputs of the differential amplifiers 11, 12, and the inputs and outputs of the final amplifier 13, in the conventional voltage comparator 1 in the case where a noise is not input to the comparator 1, the timing chart of FIG. 9 shows those in the case where a noise is input to the comparator 1. In the timing charts of FIGS. 8 and 9, an input signal is sampled during the first half period (φ1) and voltage comparison is performed during the last half period (φ2).
First, an input signal sampling operation shown in FIG. 8 will be described. At the timing of this operation, the switches S1, S3, S5, S6, S7, S8, S9, and S10 are ON, and the remaining switches S2, S4 are OFF. First, an input analog signal is stored in the capacitor C1. The voltage serving as a reference is the voltage VR supplied via the switches S5, S6.
Both of the input voltages of the differential amplifier 11 are the reference voltage VR, and the output voltage is a voltage produced by amplifying an offset voltage. The input terminals of the second stage differential amplifier 12 are connected to the input terminals of the differential amplifier 11 via the switches S5, S6, S7, S8, and hence the input voltages of this differential amplifier 12 are also the reference voltage VR. Likewise, the output voltage of the second stage differential amplifier 12 is also a voltage produced by amplifying an offset voltage, similarly to the first stage of the differential amplifier 11. The third stage is the same. Since the amplification stages are capacitively coupled in this manner and each stage is input with the reference voltage VR, the first stage offset voltage is not transmitted to the latter stages. Hence the offset voltage of the entire amplification circuit becomes the offset voltage of the final stage, i.e. the final amplifier 13. Thus with a three-stage configuration as shown in this example, the offset voltage calculated upon input can be considered as a fraction of the gain of the previous two stages, and hence can be reduced in magnitude considerably.
Next, a voltage comparison operation will be described. During the period of this operation, the switches S2, S4 annexed with the symbol φ2 in FIG. 3 are ON, and the other switches S1, S3, S5, S6, S7, S8, S9, S10 are OFF. The inputs of each differential stage (the differential amplifiers 11, 12 and the final amplifier 13) are removed from the reference voltage VR since the switches S15 through S20 are OFF. As a result, the differential amplifiers 11, 12 and the final amplifier 13 perform amplification in accordance with the variation in the inputs. Thus the comparison operation is performed.
As shown in FIG. 9, a pulsing noise may intrude immediately before the completion of sampling. In this case, the reference voltage VR is supplied to the inputs of the differential amplifiers 11, 12 and final amplifier 13 through the switches S5, S6, S7, S8, S9, S10, and hence has a time constant with the capacitors C1, C2, C3, C4, C5, C6. Therefore, the path that is charged from the reference voltage VR through the switches S5 through S10 cannot follow this noise. On the other hand, the response of the differential amplifiers 11, 12 and the final amplifier 13 is sometimes sufficiently fast.
In such a case, the differential amplifier 11 is not fixed to the reference voltage VR, and therefore executes amplification as shown in FIG. 9. The amplified noise is then output from the differential amplifier 11 and held in the capacitors C3, C4. For example, a voltage which is approximately equal to the voltage amplitude is generated. The sampling cycle may then end while such a large voltage is generated.
The differential amplifiers 11, 12 are designed to have an amplification factor of approximately ten to prevent the output voltage from saturating even when an offset voltage is present in order to increase the response speed, and are also designed such that the output amplitude is voltage-restricted to less than half of the supply voltage so as not to exceed the supply voltage following capacitive coupling and transmission to the next differential stage. When a comparison operation starts with a large voltage differential, since the output amplitude of the differential stage is restricted, the voltage differential cannot be eliminated, and hence the voltage comparator is fixed in a 0 or 1 state. As a result, the output of the AD converter outputs all 0 data or all 1 data.
Thus with a conventional AD converter, a disadvantage exists in that if a pulsing noise arises immediately before the completion of sampling, the output of the AD converter outputs all 0 data or all 1 data.

Successive approximation ad converter having pulse noise suppression


A clutch cover assembly for engaging and dis-engaging a clutch disc from a flywheel includes a clutch cover that is attachable to the flywheel. A radially inward portion of the clutch cover is formed with a plurality of bent tabs. A pressure plate is disposed within the clutch cover. A diaphragm spring is supported by the bent tabs. A conical spring is disposed between the diaphragm spring and the clutch cover. The conical spring is formed with a plurality of engagement portions on a radially inward portion thereof. A support plate has a generally annular shape and a portion of the support plate is clamped between the diaphragm spring and the clutch cover. The support plate is formed with a plurality of support portions which engage the conical spring confining axial movement of a portion of the conical spring with respect to the clutch cover. As well, the support plate is formed with a plurality of claw portions which extend into the engagement portions of the conical spring restricting rotation of the conical spring with respect to the support plate.

1. Field of the Invention
The present invention relates to a clutch cover assembly, and more particularly to a clutch cover assembly using a diaphragm spring and a secondary spring for urging a pressure plate into engagement with a clutch disc.
2. Description of the Related Art
In general, a clutch cover assembly is mounted on a flywheel of an engine and is used to transmit a drive torque of an engine to a transmission. Such a clutch cover assembly is mainly composed of a clutch cover fixed to the flywheel, a pressure plate for clamping a friction portion of a clutch disc into friction engagement with a surface the flywheel, and a spring member for biasing the pressure plate toward the flywheel.
In general, a diaphragm spring is used as the spring member mentioned above. The diaphragm spring is composed of a disc spring portion and a plurality of lever portions extending radially inwardly from an inner circumferential edge. Thus, the diaphragm spring has a function to bias the pressure plate and is moved to a function to release its spring force from the pressure plate. For instance, such a diaphragm spring typically has a release load characteristic D as shown in FIG. 9. As shown in the graph in FIG. 9, the force required to release engagement with the clutch disc increases at a generally constant rate as the release stroke increases. However, at a certain critical point, the force required to continue deflection of the diaphragm spring decreases gradually.
A clutch cover assembly is known in which, in order to improve the release load characteristics, a secondary conical spring is disposed between the clutch cover and an annular disc portion of the diaphragm spring. The conical spring is compressed between the annular disc portion of the diaphragm spring and the clutch cover. In this case, the biasing force of the diaphragm spring and the conical spring are combined. The force required to deflect the diaphragm spring must include force to deflect both the diaphragm spring and a load of the conical spring. At this time, for instance, the load characteristics may be adjusted by combining the portion of the conical spring where the load is large with the portion of the diaphragm spring where the release load is small, as a result of which it is possible to obtain flat release characteristics where the change of load is suppressed. It is therefore possible to enhance the operational feeling upon the release operation.
In the above-described conventional clutch cover assembly, it is necessary to center the secondary conical spring and prevent rotation of the secondary conical spring. For this reason, conventional configurations include a member such as a support ring is provided on the clutch cover side to thereby attain the retainment of the conical spring. Since the special member such as a support ring should be thus used, the number of the parts is increased.
Typically in a clutch cover assembly, the diaphragm spring is supported in the clutch cover. Generally, there are two methods for supporting the diaphragm spring, i.e., use of stud pins or support the diaphragm spring by tabs provided in the inner circumferential portion of the clutch cover.
There are clutch cover assemblies having stud pin type diaphragm spring type supports where a conical spring is employed. However, the inventors are not aware of any clutch cover assemblies in which the diaphragm spring is supported by the tabs where a conical spring is employed. Similar to that stated above, a problem with conical spring being used in a stud pin type diaphragm spring configuration is the increased number of parts necessary to support and restrain the conical spring and the diaphragm spring.

Clutch cover assembly having a diaphragm spring and a secondary biasing spring working in tandem


A fire fighting trainer for use in training fire fighters is provided. The fire fighting trainer includes a structure having a plurality of chambers having concrete or grating floors. Each chamber contains one or a series of real or simulated items, which are chosen from a group of items, such as furniture and fixtures and equipment. The trainer also includes a smoke generating system having a smoke generator having a smoke line with an outlet for each chamber. The trainer also includes a propane gas flame generating system having at least one propane gas pressure controller and a gas line with a burner control and one or more single element or multi-element burners for each chamber. The trainer has a main control panel for regulating the flame generating system and the smoke generating system and for controlling the fire, or fires, and smoke in each chamber. The trainer also has one or more sensor assemblies in each chamber, which senses water, foam, powder and inert gas agent application, and which is connected to the main control panel to sense and report what and where and how an extinguishing material or medium or agent is being used in each chamber during a test of trainees or fire fighters, so that the single fire or spreading fire and smoke can be simultaneously regulated or reset to suit the conditions in the chamber. The trainer includes a combination of individual sensors forming a detector assembly which may include different sensing element types, and also include temperature sensors to monitor heat levels in the chambers.

The prior art fire fighting trainer is described in U.S. Pat. No. 4,526,548, issued Jul. 2, 1985. Related patents include U.S. Pat. Nos. 3,071,872, issued Jan. 8, 1963; 3,156,908, issued Nov. 10, 1964; 3,451,147, issued Jun. 24, 1969; 3,675,342, issued Jul. 11, 1972: 3,675,343, issued Jul. 11, 1972, and 4,001,949, issued Jan. 11, 1977 and 4,303,396 issued Dec. 1, 1981.
Other related patents include U.S. Pat. Nos. 4,526,548, issued Jul. 2, 1985; 4,303,396, issued Dec. 1, 1981; 3,071,872, issued January 1983; 3,156,908, issued November 1964; 3,451,147, issued June 1969; 3,675,342, issued July 1972; 3,675,343, issued July 1972; 4,001,949, issued January 1977; 4,299,579, issued Nov. 10, 1981; and 4,303,397, issued Dec. 1, 1981.
The prior art fire fighting trainer includes a plurality of chambers having respective contents including items chosen from a group of items including furniture and fixtures and equipment, a smoke generating system having a plurality of outlets disposed in the respective chambers, and a flame generating system having a plurality of outlets disposed in the respective chambers, and a control and monitoring system.
One problem with the prior art fire fighting trainer is that there is no way to determine which ones of the extinguishment agents are being used by the fire fighters simultaneously with the testing of the fire fighters.
Another problem is that the trainer is not adapted to simulate a spreading fire. In addition, the commercial gas burners used to produce the flames allow an unacceptable build up of unburned gas when the flames are suppressed with water application.
A third problem is inefficiency of production and distribution of the simulated smoke that is used for safety and to eliminate pollutants.

Fire fighting trainer and apparatus including smoke generating means


A system for tracking a position and an orientation of an external device such as a smart watch or a handheld controller relative to a head mounted display (HMD) device is provided. A combination of active markers and passive markers on the external device may be detected by a point tracking camera of the HMD to collect position data for the external device relative to the HMD. Acceleration and/or orientation data of the external device relative to the HMD may be collected from an inertial measurement unit(s) (IMU(s)) of the external device and/or the HMD. The fusion of the position data with the data collected by the IMU(s) may allow for tracking of the external device relative to the HMD.

Virtual reality (VR) systems, or augmented reality (AR) systems, or mixed reality (MR) systems, may make use of various different types of electronic devices to generate and present virtual content, to provide for user interaction with the virtual content, and the like. For example, a user may experience and interact with virtual content in a VR/AR/MR virtual environment through a head mounted device including a display, glasses or goggles, external electronic devices such as handheld devices, wrist worn devices, and other such electronic devices. Extended operation time of the electronic devices, particularly when using somewhat power constrained electronic devices for user interaction with the virtual content, may enhance the user experience.

Low-power semi-passive relative six-degree-of-freedom tracking


A full adder circuit includes a first logical operation unit suitable for outputting an inverse of the second input signal and a first output signal corresponding to either a second input signal or the inverse of the second input signal in response to a first input signal, a second logical operation unit suitable for outputting an inverse of the first output signal and a sum signal corresponding to either the first output signal or the inverse of the first output signal in response to a carry input signal, and a third logical operation unit suitable for outputting a carry output signal in response to the inverse of the second input signal, the first output signal, the inverse of the first output signal, and the sum signal.

1. Field
Exemplary embodiments of the present invention relate to a full adder circuit, and more particularly, to a full adder circuit outputting a carry value.
2. Description of the Related Art
A full adder circuit is a basic element widely used for a digital signal processing system including an operation system. The full adder circuit is well used in novel data processing scheme for rapidly processing a large amount of information signals. Circuit design is one of main concerns for a full adder circuit improving the data processing speed in an operation system or a data processing system rapidly processing a large amount of information signals.
FIG. 1 is a circuit diagram illustrating a full adder of prior art.
Referring to FIG. 1, the full adder is a logic circuit for generating 2 outputs for 3 input bits. The 3 input bits are 2 input signals SIG_A and SIG_B and a carry input signal SIG_CIN. The full adder outputs a sum signal SIG_SUM and a carry output signal SIG_COUT. The full adder includes 2 XOR gates and 3 NAND gates.
As illustrated in FIG. 1, a first XOR gate XOR1 performs XOR operation for the input signals, for example, a first and a second input signals SIG_A and SIG_B and generates a logic high level signal, i.e., '1' when the input signals do not have the same logic level to each other. A second XOR gate XOR2 performs XOR operation for the output of the XOR gate XOR1 and the carry input signal SIG_CIN to generate the sum signal SIG_SUM. A first NAND gate NAND1 performs NAND operation for the output of the XOR gate XOR1 and the carry input signal SIG_CIN. A second NAND gate NAND2 performs NAND operation for the first and second input signals SIG_A and SIG_B. A third NAND gate NAND3 performs NAND operation for the outputs of the first and second NAND gates NAND1 and NAND2 to generate the carry output signal SIG_COUT.
As disclosed above, the full adder of prior art includes 3 NAND gates, each of which has 4 transistors, which means that the full adder of prior art has 12 transistors and leads to inefficiency in terms of tendency of high-integration. A number of the full adder or the transistors increases as a number of input signals for operation increases, which may cause an increase in chip layout size and a threshold pass delay in the circuit and thus a concern on the performance of the data processing system.


A comb filter system that utilizes host memory is disclosed. The comb filter system that utilizes host memory may include a comb filter. The comb filter system that utilizes host memory may include an allocated host memory. The comb filter system that utilizes host memory may include an interface in signal communication with the comb filter and allocated host memory.

1. Field of Invention
This invention relates to video decoders, and in particular to video decoder having a comb filter system that utilizes host memory.
2. Related Art
The complexity and flexibility of electronic processing devices such as personal computers ("PCs"), personal digital assistants ("PDAs"), two-way set top boxes (both for cable and satellite), personal video recorders ("PVRs"), cellular telephones, two-way pagers, and other host devices capable of processing information are growing a rapid pace. As such, these types of devices have become common place in today's society.
With the growth, improvement, and general acceptance of the Internet, more information is becoming accessible to these types of devices in varying forms of content leading to a fusion between these types of devices and various types of multimedia content. As an example, the growth of both cable and satellite type television systems has resulted in cable ready televisions, two-way set top boxes (the devices that interface between the cable or satellite systems and the television monitor generally known as "STBs"), digital cable, cable modems to access the Internet, Internet based web-TV, digital telephone over cable, on-demand video services, etc. Additionally, devices such as cable ready televisions, web-TVs, Internet capable video games, and PCs are increasing being connected to either cable or satellite type broadband systems to enable broadband connectivity with the Internet.
As an example, as PCs become more multimedia type devices, video and audio content are becoming important for PC users. Radio and television tuner add-on devices from numerous vendors are common place. Generally, these radio and/or television tuner add-on devices are peripheral devices that include an audio, video, or both, decoder (i.e., an audio/video decoder—also know generically as a "A/V decoder" and/or "video decoder") that is capable of receiving a broadcast composite video signal (i.e., having luminance and chrominance spectra components, also known as channels) that is transmitted in one of the world's three television transmission formats (i.e., either NTSC, PAL, or SEACAM) and converts it to a digital data stream component video signal (i.e., having red, green, and blue "RGB" or "Y PbPr") that has a format that is readable to the particular type of PC. Luminance ("Y") describes a black and white image in full detail and chrominance ("C" also referred to as "UV") describes coloration of the image. These types of video decoders may vary in the way they separate luminance and chrominance spectra in the composite video signal and generally include either a notch filter or comb filter.
In the case of video decoders utilizing a comb filter, the comb filter separates the composite video signal into both Y and C channels to reduce both cross-luma (i.e., cross-luminance) and cross-chroma (i.e., cross-chrominance) artifacts. The comb filter is utilized so that the resulting video images show fine picture detail from standard broadcasts, Laserdisk, and other composite sources. Video decoders utilizing a comb filters also reduce discolorations in fine picture detail and provide purer color overall.
In general, known video decoders utilize three-line ("3-line") adaptive comb filters (also known as three-line two-dimensional "3-line 2D" comb filters) or higher quality three-dimensional ("3D") comb filters (also know as "3D Y/C filter," "3D digital comb filter," or "motion adaptive" comb filters). As far as 3D comb filters, in addition to separating the Y and C channels of a composite video signal, a 3D comb filter also performs two additional functions. While comparing three consecutive horizontal scan lines within a single video frame, the 3D comb filter also analyzes each frame for improved image quality.
Unfortunately, known approaches to 3D comb filtering of composite video typically requires local memory frame buffers (on the video decoder) to hold the previous frames of video for use in the 3D comb filter. As a result, currently known peripheral devices utilizing 3D comb filters (such as, for example, PC TV 3D comb filter cards) have an additional standalone integrated circuit ("IC") along with a dedicated dynamic read access memory ("DRAM") to provide frame buffer storage of previous video fields required for the 3D comb filter. This additional hardware adds significant cost and complexity to the peripheral device and as peripheral devices move towards dual-tuner use, board space for all of the required additional components on the peripheral device also becomes an issue.
Therefore, there is a need for a new comb filter system on a peripheral device that does not require the utilization of dedicated DRAM on the peripheral device.


The disclosed embodiments include systems and methods for providing customer service. The system may include one or more memory devices storing software instructions. The system may also include one or more processors configured to execute the software instructions to receive customer data and location data from a client device. The one or more processors may also execute the software instructions to identify a customer and a merchant based on the received data. The one or more processors may also execute the software instructions to determine an applicable customer service option based on at least the identified merchant and the identified customer, the customer service option including at least an option to activate a credit card secondary benefit, and transmit a notification to the client device, the notification including the customer service option when the identified customer is eligible for the determined customer service option.

Financial service providers often offer various "secondary benefits" to their customers. For example, financial service providers that issue credit cards to consumers may offer various services that supplement the use of their credit cards. These programs may be used by consumers in conjunction with their credit card to receive a benefit such as rewards points, an extended warranty, an insurance plan, etc.
While benefits such as these are often useful, customers may be unaware of which services are available to them and in what situations they qualify to use them. Further, preconceived notions about such benefits may prevent customers from seeking more information about them. For example, complicated verification and processing requirements may deter customers from using secondary benefits.
Improving customer awareness of secondary benefits and ease of use may increase customer satisfaction. Therefore, a need exists to enhance use and processing of customer services, such as secondary benefits.

This patent is subject to a terminal disclaimer.

Systems and methods for providing a customer service


A system for purification of high value metals comprises an electrolytic cell in which an anode formed of a composite of a metal oxide of the metal of interest with carbon is electrochemically reduced in a molten salt electrolyte.

The properties of titanium have long been recognized as a light, strong, and corrosion resistant metal, which has lead to many different approaches over the past few decades to extract titanium from its ore. These methods were summarized by Henrie [1]. Despite the many methods investigated to produce titanium, the only methods currently utilized commercially are the Kroll and Hunter processes [2, 3]. These processes utilize titanium tetrachloride (TiCl4) which is produced from the carbo-chlorination of a refined titanium dioxide (TiO2) according to the reaction:TiO2(s)+2Cl2(g)+2C(s)→TiCl4(g)+2CO(g).In the Kroll process [2] TiCl4 is reduced with molten magnesium at ≈800° C. in an atmosphere of argon. This produces metallic titanium as a spongy mass according to the reaction:2Mg(l)+TiCl4(g)→Ti(s)+2MgCl2(l)from which the excess Mg and MgCl2 is removed by volatilization, under vacuum at ≈1000° C. The MgCl2 is then separated and recycled electrolytically to produce Mg as the reductant to further reduce the TiCl4. In the Hunter process [3,4] sodium is used as a reductant according to the reaction:4Na(l)+TiCl4(g)→Ti(s)+4NaCl(l)The titanium produced by either the Kroll or Hunter processes must not only be separated from the reductant halide by vacuum distillation and/or leaching in acidified solution to free the titanium sponge for further processing to useful titanium forms, but also require the recycling of the reductant by electrolysis. Because of these multiple steps the resultant titanium is quite expensive which limits its use to cost insensitive applications.
The US Bureau of Mines performed extensive additional investigations [1,5-8] to improve the Kroll and Hunter processes. Many other processes have been investigated that include plasma techniques [9-13], molten chloride salt electrolytic processes [14], molten fluoride methods [15], the Goldschmidt approach [16], and alkali metal-calcium techniques [17]. Other processes investigated without measurable success have included aluminum, magnesium, carbothermic and carbo-nitrothermic reduction of TiO2 and plasma reduction of TiCl4[18]. Direct reduction of TiO2 or TiCl4 using mechanochemical processing of ball milling with appropriate reductants of Mg or calcium hydride (CaH2) also have been investigated [19] without measurable success. Kroll, who is considered as the father of the titanium industry [20] predicted that titanium will be made competitively by fusion electrolysis but to date, this has not been realized.
An electrolytic process has been reported [21] that utilizes TiO2 as a cathode and carbon or graphite as the anode in a calcium chloride electrolyte operated at 900° C. By this process, calcium is deposited on the TiO2 cathode, which reduces the TiO2 to titanium and calcium oxide. However, this process is limited by diffusion of calcium into the TiO2 cathode and the build-up of calcium oxide in the cell, which limits operating time to remove the calcium oxide or replacement of the electrolyte. Also the TiO2 cathode is not fully reduced which leaves contamination of TiO2 or reduced oxides such as TiO, mixed oxides such as calcium titanate as well as titanium carbide being formed on the surface of the cathode thus also contaminating the titanium. Thus, current TiO2 cathode electrolytic processes are no more commercially viable than earlier electrolytic processes.

Thermal and electrochemical process for metal production

Materials & Electrochemical Research Corp.


A replaceable printer component includes a first memory device and a communication link. The first memory device is configured to store a first secret. The communication link is configured to communicatively link the first memory device to a printer controller when the replaceable printer component is installed in a printing system. The printing system comprises a second memory device storing a second secret. The second memory device is communicatively linked to the printer controller. The printer controller is configured to determine an authenticity of the replaceable printer component based on the first secret and the second secret.

Current printing systems typically include one or more replaceable printer components, such as inkjet cartridges, inkjet printhead assemblies, toner cartridges, ink supplies, etc. Some existing systems provide these replaceable printer components with on-board memory to communicate information to a printer about the replaceable component, such as ink fill level, marketing information, etc.

Authenticating a replaceable printer component

Hewlett-Packard Development Company, L.P.


A device for sharpening a dental instrument has a housing with a clamp movably mounted on the housing. The clamp fixes a dental tool in a holding device at a predetermined position. The dental tool is then sharpened on a fixed, but rotatable sharpening stone. The precision sharpening device includes at least one vertically fixable tool holding mount, and at least one fixed holding post to permit the tool holding mount to rotate horizontally to the sharpening stone.

Gum disease is now a very prevalent human health problem. Left untreated, gum disease can cause a substantial health problem. Partial or complete loss of teeth can result from gum disease, with associated pain and discomfort therefrom. Lost teeth are, of course, a major health problem. To treat the gum disease problem, periodontal procedures are applied.
To carry out periodontal procedures, a dentist is required to use special curettes. There are many different types of curettes. The curette is used to remove hardened deposits below a patient's gum line. Each curette needs to be very sharp, in order to remove these deposits. Each instrument is designed with a different blade angle, depending on the area of the patient's mouth in which the hygienist or dentist is working. The cutting edge of an instrument is angled or otherwise varied in this respect. When sharpening an instrument, it is very important to preserve the shape and angle of the blade.
Uniform removal of metal is important, because otherwise, the shape of the instrument can be changed; especially with regard to the angle of the lateral surface relative to the surface of the face. With few exceptions, only one cutting edge per tip of an instrument and only one lateral side must be ground during sharpening. The other lateral side is ground on a few designs of curettes, for example a sickle or a universal.
So therefore, in order to sharpen each instrument, a machine must be designed to provide a precise and a very accurate angle for each instrument. By precise is meant that the same angle on each particular instrument must be produced every time it is sharpened. Each instrument has a different angle, for different uses in different areas of the mouth.
It is highly desirable, even required, to have sharp instruments. Still it is just too costly to replace an instrument, merely because it is dull. Yet a sharpening device to precisely produce the desired sharp edge at the desired angle is not known. In fact, there is no known sharpening device for this purpose.
All currently known sharpening devices inherently rely on the operator's hand to hold the instrument to be sharpened in the proper position with respect to the sharpening stone. This factor creates a major problem, because the position of the operator's hand may change by as much as ten degrees without knowledge thereof by the operator. This factor causes an uneven removal of the lateral surface of the instrument, making the entire sharpening process very time consuming, inefficient, and tedious.
One known sharpening device requires placing the instrument on an abrasive surface, and vibrating the instrument very rapidly back and forth thereon. The hygienist, dentist or assistant places the instrument on the stone, and attempts to angle the instrument parallel to the line of the blade. This procedure is extremely tedious because the instrument usually has a round handle; and the lateral surface of the instrument, which needs to be removed in order to grind a cutting edge, has a varying angle. The angle of some instruments varies so often, that this sharpening procedure using this device just does not work to uniformly sharpen an instrument with the required accuracy.
Another known sharpening device has angles marked on a protractor-like scale for use with each instrument to be sharpened. The defect in this instrument is that it depends on a person being able to provide the same angle with his or her hand. Unfortunately, by human error, especially without a highly skilled person doing the sharpening, this device is inherently inadequate for producing the same surface on an instrument, because the lateral surface is only about one millimeter to two millimeters in width, and which needs to be preserved in order to keep the instrument in good working condition.

Method and device for sharpening chiral blades of dental instruments


A leveling device for correcting defective shape of a strip by repeatedly bending the strip under a tensioned condition of the strip, comprising a tension leveler including a stretching roll unit for correcting local elongations of the strip and a C-warp correcting roll unit for correcting the warp in the crosswise direction of the strip, and at least a tension fluctuation suppressing means for suppressing the tension fluctuation transferred from the bridle rolls and preventing the generation of charter mark. The tension fluctuation suppressing means may be composed of a rotary resistant body of at least two deflector rolls or of a pair of pinch rolls arranged one above the other.

The present invention relates to a leveling device, and in particular, to a leveling device for correcting defective shapes of a strip and to a leveling method therefor.
A conventional leveling device is shown in Fig. 1 of Japanese Patent Unexamined Publication No. 63-149015. As shown there, the leveling device is mainly composed of a tension leveler, inlet side bridle rolls located at the inlet side of the tension leveler, and outlet side bridle rolls located at the outlet side of the same. A strip is leveled by repeatedly receiving bending actions as being tensioned by means of the inlet side and outlet side bridle rolls.
In the above-mentioned leveling device, however, chatter marks are apt to be generated on the surface of the strip, thereby deteriorating the quality of the products. Especially, this phenomenon is undesirable in the present time where the requirement for flatness is strict. Here, the term "chatter mark" is used for expressing a striped pattern extending in the crosswise direction of the strip with a small pitch on the strip surface, which has, when viewed in detail, a wave-like shape having small wave heights.
A conventional means for preventing the generation of chatter marks is disclosed in Japanese Patent Unexamined Publication No. 58-151918, where a roll unit is composed of small-diametral rolls and large-diametral rolls located at the front and rear sides of the small-diametral rolls with the strip interposed between the small-diametral rolls and the large-diametral rolls, and a plurality of these roll units are arranged on a line.
In the above-mentioned conventional art, since the winding angle of the small-diametral rolls is excessive, curvature fluctuation of the strip is generated due to the vibration of the strip, thereby generating the chatter marks. As a solution for suppressing the curvature fluctuation, the above-mentioned roll arrangement has been developed.
In the above-mentioned prior art, however, no consideration is paid to the fact that the chatter marks can be prevented by decreasing the passing speed of the strip to a very low level, for example, as low as 10 m/min.
In consequence, the generation of chatter marks can not be prevented by merely arranging great-diametral rolls in the front and rear sides of the small-diametral rolls, especially, in case the flatness requirement for the strip is strict.
On the other hand, Japanese Patent Unexamined Publication No. 56-128623 discloses an arrangement where a tension distribution control device movable in the crosswise direction of the plate, is provided between an inlet side bridle roll or an outlet side bridle roll and a tension leveler.
For obtaining an excellent shape control of the strip, the elongation of the strip in the crosswise direction is controlled by applying a suitable tension distribution to the strip in the same direction.
In the above-mentioned prior art, however, nothing is referred to with respect to the prevention of chatter marks. Further, it is clear that the chatter marks can not be prevented by merely providing the above-mentioned tension distribution control device, for the reason below.
Namely, in this tension distribution control device, since the tension distribution is applied along the widthwise direction of the strip, the influence of the tension distribution control device on the strip along the widthwise direction varies in the widthwise directions, and accordingly, the chatter marks can not be prevented.
Further, as shown in Fig. 6 of the above-mentioned Japanese Patent Unexamined Publication No. 56-128623, since the roll has a tapered portion, it is clear that the influence varies in the widthwise direction of the strip.
In addition, this tension distribution control device can be applied only to case the strip is formed with rims along the side edges of the strip, and can not be applied to a usual case.


An Ni-based bearing alloy consisting, by weight, of 9-30% Cr, 5-19% Fe, 0.1-1.5% Si, 2-22% Co, 1.4-11.0% Mo, and the balance Ni and incidental impurities, said alloy having a matrix in which hard particles of a Co-Mo-Cr-Si alloy and/or BN are uniformly dispersed in weight ratios of 5 to 35% and not more than 5.0, respectively. The Ni-based alloy matrix provides superior heat resistance. Hard particles of Co-Mo-Cr-Si alloy uniformly dispersed in the matrix improve sliding characteristic with or without uniform dispersion of Bn as a solid lubricant, whereby the bearing alloy exhibits superior heat resistance and sliding characteristic when used in high temperature oxidizing atmosphere.

1. Field of the Invention
The present invention relates to a high temperature bearing alloy for use in high temperature oxidizing atmosphere and also to a method of producing the same.
2. Description of the Related Art
Hitherto, materials of a type composed of a base metal such as copper or iron and containing a solid lubricant such as graphite dispersed or embedded therein have been used as materials of bearings which are used in high temperature oxidizing atmosphere These known materials, however, cannot be used satisfactorily at temperatures exceeding 500.degree. C. or so, due to rather inferior heat-resistance exhibited by the base metal and the solid lubricant. In order to cope with demands for higher sliding characteristic, materials have recently been proposed which are produced by dispersing hard particles of Co-Mo-Cr-Si alloy in heat-resistant steels by using powder metallurgical technique Such materials are usable, as disclosed in Japanese Patent Unexamined Publication No. 3-24249, as bearing materials which are required to operate at high temperatures up to 700.degree. C. or so.
In recent years, there is a demand for bearing materials used at still higher temperatures exceeding 700.degree. C., such as the bearings for supporting, for example, exhaust gas control valves used in gasoline or diesel engines, gas control valves used in gas turbines, and so forth. Unfortunately, known bearings could not fully meet such demand because they are safely usable only at temperatures not higher than 700.degree. C.
Attempts have been made to use heat-resistant alloys or ceramics as the bearing materials, but such attempts also are unsuccessful due to high friction coefficients exhibited by such types of materials.

High temperature bearing alloy and method of producing the same