A metal cord is formed by twisting two spirally preshaped metal filaments together with a twisting pitch P. The metal filament has not only the spiral shape formed by twisting, but retains so much of its spiral preshape as to have a pitch p equal to 0.20-0.50 times the twisting pitch and a diametric height h of 0.05-0.25 mm. The retained spiral shape is in the same rotary direction as the direction in which the filaments are twisted together.

This invention relates to a metal cord for reinforcing a rubber article having excellent corrosion resistance and fatigue resistance and to a composite material comprising rubber and the metal cord embedded in the rubber as a reinforcing material, such as a vehicle tire, a conveyor belt and a high-pressure hose.
A metal cord for reinforcing a rubber article is made of high carbon steel wires (JIS G 3502 piano wire rods) having their surfaces placed with brass, copper or zinc in order to impart thereto an adhesive property with rubber. Such wires are drawn to a diameter of 0.1 to 0.5 mm and are then twisted in a single layer or in a plurality of layers. They are widely used as reinforcing materials for vehicle tires, conveyor belts and high-pressure hoses. For example, of a radial tire for a passenger car, metal cords having a 1.times.4 or 1.times.5 single-layer twisting construction which are formed by twisting four or five metal filaments together are used as a reinforcement of the belt portion.
The quality characteristics required for a metal cord for reinforcing rubber include adhesion with rubber, resistance to corrosion, resistance to fatigue and various mechanical properties (such as breaking load, rigidity, etc.). Firstly, we shall discuss the resistance to corrosion. If part of the metal cord embedded in rubber were not covered with rubber, or if the tire were to ride over a stone or a nail while travelling on a road and the damage in the tire caused by the stone or nail were to reach the metal cord, water could infiltrate through the damaged part into the cord and cause a premature corrosion of the cord, thus lowering its breaking load and fatigue resistance. Also, the adhesion strength between the cord and rubber will decrease, causing peeling and thus separation. The quality of the tire would drop markedly.
The widely used 1.times.5 or 1.times.4 closed cords (C.C.) have sections as shown in FIGS. 4A, 4B. In the center of these metal cords, there exists a rubber-free hollow space because rubber penetration into the cord is insufficient. A composite material comprising rubber and a metal cord having such a hollow space has a short life, because water can infiltrate into the hollow space, thus causing such problems as corrosion of the metal cord and separation between the metal cord and rubber.
Trials have been made to eliminate such rubber-free portions to improve the metal cords. For example, Japanese Unexamined Patent Publication 55-90962 discloses an open cord as shown in FIG. 5 in which the metal filaments 2 are twisted together in such a way as to form gaps between the adjacent metal filaments. Japanese Examined Patent Publication 58-31438 proposes as shown in FIG. 6 a parallel 2+2 cord having substantially no hollow space inside. Both cords are actually being used as reinforcing materials for tires.
Efforts are being made to reduce the emission of exhaust gas from automobiles in order to answer the growing concerns about environmental protection. Vigorous efforts are especially directed to the development of low fuel-consumption cars, because reductions in fuel consumption directly lead to reductions in the emission of exhaust gas. It is also required that vehicle tires to be lightweight in order to reduce the rolling resistance as well as the entire vehicle weight. For this purpose, trials have been made to reduce the diameter of the metal cord and to simplify the twisted configuration of the cord to reduce the thickness of the rubber covering.
For example, Unexamined Japanese Patent Publications 62-117893 and 62-234921 disclose very simple 1.times.2 cords in which two metal filaments 2 are simply twisted together as shown in FIGS. 2(A)-2(C). This type of cord is free of spaces inside and thus their filaments are entirely covered with rubber aspect for the contact portions between the filaments. Resistance to corrosion is thus good. Unexamined Japanese Patent Publication 2-229286 teaches a 1.times.2 cord in which the degree of preshaping of the two filaments are set within such a range as to provide partial gaps between the metal filaments, thus improving the rubber covering ratio and thus the corrosion resistance.
The 1.times.2 cords disclosed in Unexamined Japanese Patent Publications 62-117893 and 62-234921 exhibit excellent corrosion resistance because they are completely covered with rubber and also serve to reduce the weight of vehicle tires because they are made up of a minimum number of filaments. But they have drawbacks. Namely, in order to use 1.times.2 cords in a passenger car tire in place of 1.times.4 or 1.times.5 cords, which have heretofore been widely used, filaments having a larger diameter had to be used in order to maintain the same tenacity and rigidity as those of the metal cords made of greater number of filaments. Also, as viewed in cross section as in FIGS. 2B and 2C, 1.times.2 cords have their filaments arranged either horizontally of vertically. Thus, they have irregular shapes in the longitudinal direction.
A cord made of metal filaments having a large diameter and having irregular shapes in the longitudinal direction exhibits inferior resistance to fatigue (bending fatigue and compressive fatigue). If it is used in a belt portion of a passenger car tire, compressive stress will act on the metal cord repeatedly due to buckling while the car is turning a corner at high speed. This cord exhibits poor resistance to compressive fatigue to such repeated buckling.

Metal cord and composite material comprising the metal cord and rubber


A fuel injector including a tubular casing having an axial fuel passage. Disposed within the fuel passage are a valve seat element, a core cylinder, and a valve element axially moveably disposed therebetween and opposed to the core cylinder with an axial air gap. An electromagnetic actuator cooperates with the casing, the valve element and the core cylinder to form a magnetic field forcing the valve element to the open position against a spring between the valve element and the core cylinder upon being energized. The casing includes a reluctance portion producing an increased magnetic reluctance and allowing the magnetic field to extend to the valve element and the core cylinder through the air gap. The reluctance portion has a reduced radial thickness and an axial length extending over the air gap.

The present invention relates to fuel injectors suitably used for injecting fuel to an engine, for instance, an automobile engine.
Generally, fuel injectors used for automobile engines include a tubular casing having an axial fuel passage and made of magnetic metal. A valve seat is disposed at one end of the fuel passage and has a fuel outlet. A core cylinder is disposed within the fuel passage in axially spaced relation to the valve seat. A valve element is axially moveably disposed within the fuel passage. An electromagnetic actuator is provided for forcing the valve element to an open position upon being energized. In the open position, the valve element is out of contact with the valve seat to allow fluid to be injected through the fuel outlet.
Japanese Patent Application First Publication No. 11-6467 discloses such an electromagnetically operated fuel injector. The fuel injector of this related art also includes a casing, a core cylinder axially opposed to the valve element with an axial air gap, and a non-magnetic joint disposed between the casing and the core cylinder. When the electromagnetic actuator is energized, a magnetic field extends to the core cylinder and the valve element via the axial air gap, so that the valve element is attracted by the core cylinder and moved to the open position. The non-magnetic joint suppresses a short-cut of the magnetic field which will be caused between the casing and the core cylinder. If the short-cut is caused, the magnetic field will form a closed magnetic circuit without passing through the axial air gap between the core cylinder and the valve element. This will cause reduction of the magnetic force acting on the valve element and the core cylinder.
Japanese Patent Application First Publication No. 2000-8990 also discloses an electromagnetically operated fuel injector of the same type as described above. The fuel injector includes a casing formed by a metal pipe, and an annular non-magnetic portion disposed in an axial-middle position of the casing. Upon energizing the electromagnetic actuator, the annular non-magnetic portion prevents the short-cut of the magnetic field. The annular non-magnetic portion is formed by subjecting the axial-middle portion of the metal pipe to heat treatment, for instance, induction heating.
Japanese Patent Application First Publication No. 2001-27169 discloses such an electromagnetically operated fuel injector of the same type as described above. The fuel injector includes a tubular casing having a fuel outlet at one axial end portion thereof, a resin cover covering an opposite axial end portion of the casing, a seal disposed on near the one axial end portion of the casing, and a resin protector for protecting the one axial end portion of the casing and the seal. Upon manufacturing the fuel injector, the parts such as a valve seat, a valve element, a core cylinder and an electromagnetic actuator are mounted to the casing, and the resin cover is formed by injection molding. An axial air gap (a valve lift amount) between the valve element and the core cylinder is adjusted using a tool. After the adjustment work, the resin protector previously molded is mounted onto the one axial end portion of the casing together with the seal.

Fuel injector and method of manufacturing the same


A method and system for retrieving information in response to a query by a user. The method includes the steps of receiving a signal s having a value corresponding to a relevance-ranking algorithm score of a retrieved document, receiving a signal q having a value corresponding to the number of words in the query and a signal v having a value corresponding to the coordination level of the retrieved document and query (i.e., the degree of overlap between the document terms and the query terms), and generating an adjusted score s1 dependent on the signal s, the signal q and the signal v. The adjusted score s1 takes the coordination level into account for small values of q and gradually decreases the importance of the coordination level as q increases. The system of this invention includes a computer-based system for carrying out the method of this invention.

1. Field of the Invention
The present invention relates generally to an information retrieval system, and more specifically to an information retrieval system adapted to improve ranking of documents retrieved in response to short queries.
2. Description of the Background Art
An information retrieval (IR) system is a computer-based system for locating, from an on-line source database or other collection, documents that are relevant to a user's input query. Until recently, most commercial IR systems, such as DIALOG.RTM. or LEXIS.RTM., used Boolean search technology. In a Boolean search system, users must express their queries using the Boolean operators AND, OR, and NOT, and the system retrieves just those documents that exactly match the query criteria. Typically, there is no score or other indication of how well each document satisfies the user's information need.
However, after years of research demonstrating the superiority of relevance-ranking, commercial systems began to offer this capability. Today millions of people use IR systems that employ relevance-ranking, also known as ranked searching, which is based on the "vector space model." In a relevance-ranked search system, users can simply type an unrestricted list of words, even a "natural-language" sentence, as their query. The system then does a partial matching computation and assigns a score to every document indicating how well it matches the user's interest. Documents are then presented to the user in order, from the best matching to the least matching. Relevance-ranking is described in Salton, et al., Introduction To Modern Information Retrieval, McGraw-Hill Book Co., New York (1983). Relevance-ranking IR systems are commonly used to access information on the Internet, through systems based on the WAIS (Wide Area Information Servers) protocol or through a variety of commercial World Wide Web indexing service such as Lycos, InfoSeek, Excite, or Alta Vista. Relevance-ranking is also used in commercial information management tools such as AppleSearch, Lotus Notes and XSoft Visual Recall for searching databases or collections from individual or shared personal computers.
Relevance-ranking systems work as follows. In relevance-ranking, each word in every document of a collection is first assigned a weight indicating the importance of the word in distinguishing the document from other documents in the collection. The weight of the word may be a function of several components: (1) a local frequency statistic (e.g., how many times the word occurs in the document); (2) a global frequency statistic (e.g., how many times the word occurs in the entire collection of documents); (3) the DF measure (how many documents in the collection contain the word); and (4) a length normalization statistic (e.g., how many total words are in the document).
The following example demonstrates one possible term-weighting scheme for a relevance-ranking system. First, assume that a collection contains one-hundred (100) documents with one particular document containing only the text "the dog bit the cat." Assume further that the word "the" occurs in all 100 documents while the word "dog" occurs in five (5) documents and the word "cat" occurs in two (2) documents. Here, we use Term Frequency (TF), the number of times the word occurs in a particular document, as our local frequency statistic:
term=dog, TF=1, PA1 term=the, TF=2, PA1 term=cat, TF=1. PA1 term=dog, DF=5/100, PA1 term=the, DF=100/100, PA1 term=cat, DF=2/100, PA1 term=dog, IDF=100/5=20, PA1 term=the, IDF=100/100=1, PA1 term=cat, IDF=100/2=50. PA1 term=dog, TF.times.IDF=1.times.20=20, PA1 term=the, TF.times.IDF=2.times.1=2, PA1 term=cat, TF.times.IDF=1.times.50=50.
Here, we use DF as our global statistic:
where DF=number of documents containing the term total number of documents.
The inverses of DF (IDF) are calculated as follows:
For this example, we will not use a length normalization statistic. Thus the final weights of each term using TF.times.IDF are as follows:
This list of weighted terms serves as the vector that represents the document. Note that terms found in more documents (such as "the") have lower weights than terms found in fewer documents (such as "cat"), even if they occur more frequently within the given document.
Every document in the collection is then assigned a vector of weights, based on various weighting methods such as TF.times.IDF weighting and weighting that takes TF.times.IDF and a length normalization statistic into account. After a query is entered, the query is converted into a vector. A similarity function is used to compare how well the query vector matches each document vector. This produces a score for each document indicating how well it satisfies the user's request. One such similarity function is obtained by computing the inner product of the query vector and the document vector. Another similarity function computes the cosine of the angle between the two vectors. Based on relevance-ranking, each document score is calculated and the retrieved documents are then outputted sequentially from the one with the highest score to the one with the lowest score.
A study performed by D. E. Rose and D. R. Cutting on an experimental information retrieval system by Apple Computer, Inc. of Cupertino, Calif. shows that casual users of IR systems prefer to issue short queries. During a four-week period from December 1995 to January 1996, over 50% of the 10,044 queries issued by at least 4,686 users in Apple's system contained only a single word, and no query was longer than 12 words. The mean query length was 1.76 words. A subsequent study performed by Rose and Cutting shows that out of 10,000 queries issued in Apple's system, over 53% were single-word queries and 94% were queries of three words or less. Similar results were obtained for queries placed in systems by Excite and the THOMAS system provided by the federal government. Rose, Daniel E. and Cutting, Douglass R., Ranking for Usability: Enhanced Retrieval for Short Queries, (submitted for publication, September 1996). Other studies have confirmed the preference of casual users for issuing short queries. Hearst, Marti A., Improving Full-Text Precision On Short Queries Using Simple Constraints, Fifth annual Symposium on Document Analysis and Information Retrieval, pp. 217-225 (1996).
The interfaces of the major Internet search services also encourage queries having few terms. The four well-known World Wide Web searching services (Lycos, InfoSeek, Excite, and AltaVista) present users with an entry field that accepts less than one line of text.
The statistical methods that provide relevance-ranking, such as "TF.times.IDF weighting" with the cosine similarity metric, attempt to "reward" documents that are well-characterized by each query term. In practice, this means that a document that has a very high value for some of the query terms may be ranked higher than a document that has a lower value for more of the query terms. Relevance-ranking algorithms are intended to achieve this outcome. However, users sometimes find that for short queries submitted to relevance-ranking IR systems, the users' goal of obtaining the most useful ordering of search results, from the most relevant document to the least relevant document, is not attained. Existing relevance-ranking algorithms may, in some circumstances when a query is short, assign higher scores to certain documents with low overlaps than to other documents with high overlaps. Overlap is determined by the number of terms common between the query and the document. This problem is exemplified in FIG. 1, which is a table partially showing the results of a short query entered into the Apple Developer web site. The query term entered by a user was "express modem," whereby the user probably intended to retrieve documents about the Apple Computer product by that name. The search results included 103 documents, and the documents with the top ten relevance scores are shown in FIG. 1. Column I shows the ranking of the search results based on relevance scores indicated by the symbol *. Column II shows the titles of the retrieved documents, and column III identifies which terms in the query were responsible for the documents being retrieved. The highest scoring document contained only the term "modem," as shown in row (a). This document discussed modems in general, without mentioning the term "express modem." The second highest scoring document contained only the term "express" (as shown in row (b)) and was not relevant to modems. The third highest scoring document did discuss the "express modem" product, as shown in row (c).
FIG. 1B shows the method used by the prior art to produce the results described above with reference to FIG. 1. The method starts with step 150, where a query defining the search criteria is issued to a database or other information retrieval system. Next, step 155 identifies a set of documents that meet the criteria defined in the query. Finally, step 160 assigns a relevancy ranking to each of the documents in the identified set using conventional relevancy ranking algorithms discussed above. A possible solution to the short query ranking problem discussed above is to use queries based on Boolean search technology. However, the Boolean approach sacrifices the benefits of relevance-ranking, while research has shown that most casual users do not understand Boolean logic and have difficulty in using Boolean IR systems. Attempts have been made to ease user problems with Boolean systems with solutions that blend Boolean and relevance-ranking. Noreault T., Koll, M., and McGill, M. J., Automatic Ranked Output From Boolean Searches In SIRE, Journal of the American Society For Information Science, Vol. 26, No. 6, pp. 333-39 (1977); and Salton, G, Fox, E. A., and Wu, H., Extended Boolean Information Retrieval, Communications of the ACM, Vol. 26, No. 12, pp. 1022-1036 (1983). However, the above approaches combine Boolean and relevance-ranking, and consequently users are still required to express their queries as Boolean expressions if they wish to take advantage of the Boolean constraints. In addition, the above approaches do not take query length into account when scoring the relevance of documents.
G. Salton and C. Buckley have suggested that the statistical weighting of a short query should differ from the statistical weighting of a long query. Salton, G. and Buckley, C., Term-Weighting Approaches In Automatic Text Retrieval, Information Processing & Management, Vol. 24, No. 5, pp. 513-523 (1988). Salton and Buckley did not, however, suggest that a matching algorithm should be modified as a function of query length, nor did they propose a function that changes the statistical weighting scheme of query terms as the query lengthens or shortens.
One study that notes the short query problem is by Hearst, Marti A., Improving Full-Text Precision On Short Queries Using Simple Constraints, Fifth Annual Symposium on Document Analysis and Information Retrieval, pp. 217-225 (1996). However, this approach limits ranking within the confines of the Boolean search, and only if users input their query in a prescribed way. In addition, this approach imposes limitations on users in their method of query input, and does not take query length into account. Additionally, although Hearst's system is described as targeting "short" queries, it appears to be optimized for much longer queries (8 words or more) than most users actually enter.
Furthermore, none of the above approaches work on an arbitrary relevance-ranking system.
Thus, there is a need for a system and method that overcome the short query problem of relevance-ranking information retrieval systems.

System and method for improving the ranking of information retrieval results for short queries


A method for rendering a light field comprises projecting rays from a viewpoint positioned at a first side of a spatial light modulator (SLM) to a clipping plane positioned at an opposing side of the SLM to form an elemental view frustum within a three-dimensional scene and rendering objects within the elemental view frustum to generate components of a first elemental image for the first elemental region. The SLM may include a tiled array of non-overlapping elemental regions and a top edge and a bottom edge of a first elemental region of the non-overlapping elemental regions are intersected by the rays to form the elemental view frustum. Furthermore, the light field may include the first elemental image and additional elemental images corresponding to the array of elemental regions and each one of the additional elemental images is rendered using an additional elemental view frustum.

Creating a comfortable visual experience is important to the success of modern virtual reality (VR) and augmented reality (AR) systems. A wide field of view, high resolution, interactivity, view-dependent occlusion, and continuous focus cues are significant features for providing a comfortable visual experience. However, conventional VR systems typically fail to provide many of these features, resulting in user discomfort. Thus, there is a need for addressing these issues and/or other issues associated with the prior art.

System and method for near-eye light field rendering for wide field of view interactive three-dimensional computer graphics


Cooling of densely packaged semiconductor devices is achieved by microchannels which extract heat by forced convection and the use of fluid coolant located as close as possible to the heat source. The microchannels maximize heat sink surface area and provides improved heat transfer coefficients, thereby allowing a higher power density of semiconductor devices without increasing junction temperature or decreasing reliability. In its preferred embodiment, a plurality of microchannels are formed directly in the substrate portion of a silicon or silicon carbide chip or die mounted on a ground plane element of a circuit board and where a liquid coolant is fed to and from the microchannels through the ground plane. The microchannels comprise a plurality of closed-ended slots or grooves of generally rectangular cross section. Fabrication methods include deposition and etching, lift-off processing, micromachining and laser cutting techniques.

1. Field of the Invention
This invention relates to convection cooling of high power semiconductor devices and more particularly to microchannel cooling of semiconductor devices formed on a chip of semiconductor material including silicon and silicon carbide.
2. Description of the Prior Art
As the state of the art of semiconductor technology advances and more particularly to those types of devices which are known as power semiconductor devices, and the circuitry associated therewith, there is a continued demand that such devices operate faster and handle more power, while being ever smaller and lower in cost. The semiconductor industry has responded with the development of integrated circuit chips including thereon a large number of transistor devices such as bipolar transistors including power switching devices such as insulated gate bipolar transistors which are particularly applicable for use in medium to high power (1 to 100 kW or more) power converters. Moreover, these devices are currently being incorporated in densely packaged structures that can handle kilowatts of power.
The greatest limitation in the design of such low cost, light weight, high power devices is providing reliable cooling of the densely packaged components. Current state of the art electronic packaging techniques typically utilize redundant parts and excess substrate boundary regions as well as operating the electronics at less than their rated values. For example, in transmitters, silicon RF transistors are typically operated below their power output capability and spaced apart from one another by relatively large separation distances in order to keep them cooled to standardized operating temperatures. The maximum device junction temperature of a silicon bipolar transistor, as dictated by system reliability studies, is normally between 125 and 135.degree. C. The same techniques apply to power switching devices.
More recently, the use of silicon as substrates is being replaced by the use of silicon carbide which can tolerate increased operating temperatures. These devices, however, are still limited internally by known power density and thermal considerations. In conventionally cooled power semiconductors, moreover, the heat generated in a silicon substrate is conducted through several layers of material to an air or liquid cooled heat sink.

Method of extracting heat from a semiconductor body and forming microchannels therein


A method for providing tactile feedback comprises displaying a visual representation of a physical object having at least one haptic property, generating time-varying data associated with the at least one haptic property from the visual representation, sending the time-varying data to a computing device including a feedback apparatus electrically connected to the computing device, and generating the tactile feedback via the feedback apparatus in response to a pressure on the feedback apparatus applied by a user.

Online and mobile commerce has been increasing at a rapid pace from year to year, especially with the increasing adoption of mobile devices, such as, for example, smartphones and tablets. Using, for example, mobile phone or tablet applications, mobile web sites, or a combination thereof, shoppers are able to use online stores or shopping sites to search for, compare, examine, and purchase items using their mobile devices.
Using mobile devices to purchase goods permits a consumer to make purchase decisions at any time and any place, at his or her convenience. However, shopping online or with a mobile device also prevents a consumer from examining an article or physical object in person, not allowing the consumer to touch, feel, or try using the product, all of which can presently only be done in a store or similar physical setting where both the product and purchaser are present.
In addition, when practicing remote or tele-medicine, a doctor remains unable to feel a wound without being co-located with a patient.
Some of the restrictions of mobile and online commerce, or remote medicine have been addressed. For example, high-resolution, full-color displays on higher end devices, and increasingly on mid- and lower-level devices, make it possible to present very realistic images of an item or medical condition. Audio makes it possible to hear an object (for example, an engine or a musical instrument), or to hear a sales associate explaining an item. In addition, video makes it possible to see an item in action, or being used.
Haptic technology, or haptics, permits a user to receive tactile feedback to some degree through a device by applying forces, vibrations, and/or motions to the user. However, with current technology, the mobile and online consumer, or remote doctor still remains unable to accurately feel or simulate the feeling of touching a wound, scar, or a desired product, such as an article of clothing, when making a purchase.

This patent is subject to a terminal disclaimer.

Haptic accessory and methods for using same

International Business Machines Corporation


A method and apparatus for measuring the content of carbon dioxide in an aqueous medium, particularly boiler condensate from an electrical power plant. The apparatus comprises a container or housing defining an elongated vertical indicator chamber and a parallel vertical reference chamber which are connected by a generally horizontal passage. An indicator electrode and a reference electrode are mounted in the indicator chamber and reference chamber, respectively. The lower end of the indicator chamber is open, and the open end is enclosed by a membrane of microporous polytetrafluoroethylene. The lower end of the indicator electrode is flat or planar and is located in close proximity to the inner face of the membrane. A filling liquid consisting of pure water is located within both chambers in contact with the respective electrodes. The apparatus can be mounted in a condensate bleed line of a power plant. The condensate in the bleed line is in initially adjusted in pH to a value of about 4.5 and then is flowed in contact with the outer face of the membrane. Carbon dioxide in the condensate will diffuse through the membrane to provide a differential in electrical potential, which serves as a measurement of the carbon dioxide content.

In an electrical power plant utilizing steam operated turbines, a major portion of the steam condensate is recycled and reused to generate additional steam. The condensate can contain dissolved carbon dioxide and through the recycling, the carbon dioxide content can increase. It has been found that dissolved carbon dioxide can be corrosive to the turbines, as well as other metal components of the power plant. Also, dissolved carbon dioxide can contribute to scale accumulation which can decrease the thermal efficiency of heat exchange surfaces. Therefore, it is desirable to measure the carbon dioxide content in boiler condensate so that additional makeup water can be added to the condensate to maintain the carbon dioxide content within required limits.
It is recognized that the total carbonate species in an aqueous carbonate system can consist of carbon dioxide, bicarbonate, carbonate, and carbonic acid, and the equilibrium concentrations of the various carbonate species in aqueous solution are controlled by the pH of the solution. More specifically, at a pH below about 4.5, the carbonate species will consist entirely of carbonic acid. As the pH is increased to a value of about 8.5, the carbonic species will consist entirely of bicarbonate and as the pH is raised above 8.5, the predominant carbonate species will be carbonate.
Various devices have been employed in the past to measure the dissolved carbon dioxide content in an aqueous medium. One method of determining the carbon dioxide content is through bicarbonate titration, in which the pH of the water sample is initially adjusted to a value of 8.5, to convert the total carbonate to the bicarbonate form. The solution is then titrated to a pH of 4.5, converting the bicarbonate to carbonic acid, and the amount of titrating solution required to achieve this pH is a measure of the carbon dioxide content.
Differential titration is similar to bicarbonate titration, in that it relies on initial adjustment to a pH value of 8.5 to convert the total carbonate concentration to bicarbonate. The sample is then titrated to a pH of 5.0 to produce carbon dioxide, and the carbon dioxide is then removed from the sample by heating to the boiling point. The sample is then readjusted to the pH value of 8.5 and titrated to a pH of 5.0. The difference between the two titrations allows the total starting carbonate free of non-volatile acid/base interferences to be determined.
Another method that has been used to measure the free carbon dioxide present in an aqueous sample is direct titration. In contrast to the above two methods that measure the total carbonate concentration, this method only measures the free carbon dioxide present in the sample. The sample is titrated with sodium hydroxide to a pH of 8.5 to convert the total carbonate to sodium bicarbonate, and assumes the carbon dioxide is the only acidic species present in the sample.
Electrical conductivity can be used to measure the content of carbon dioxide in water, when carbonate species are the predominant anions, and the pH is confined to a narrow range. In this situation, the conductivity effectively monitors the carbonate concentration. However, the cell must be standardized with a reference solution of known conductivity to calculate a cell constant.
Another device that has been used commercially for monitoring carbon dioxide in condensate water at ppm levels is the Severinghaus type probe. This probe consists of a potentiometric glass pH probe and a thin layer of bicarbonate/sodium chloride filling solution is enclosed between the outer glass surface of the probe and a silicone rubber membrane. An internal reference electrode, which maintains its potential via the chloride content of the filling solution, is included. The analytical response in this probe is based upon the change in pH of the filling solution, due to carbon dioxide diffusion through the membrane into the thin layer of carbonate solution which produces a potentiometric signal.
A further device for measuring dissolved carbon dioxide based on potentiometry is the Scarano probe. In this probe, two electrodes of the same metal are utilized with a filling solution of pure water. A small relatively stable water layer is trapped between the working end of an indicator electrode and a gas permeable membrane formed of silicone rubber. Diffusion of carbon dioxide from the sample through the membrane to this water layer results in changes of surface pH at the electrode, and the change in metal surface oxidative potential resulting from the pH change determines the analytical signal.
While a number of devices for measuring the content of carbon dioxide in condensate have been utilized in the past, as described above, none of these devices have been capable of providing a rapid and stable response at sub-ppm levels, such as below 100 ppb.

Method and apparatus for measuring the content of dissolved carbon dioxide in an aqueous medium


A fluid reservoir for a penile implant device that includes a body portion having a sleeve from which a tube may extend. The body portion includes support structure positioned at an interior surface of the body portion near an orifice of the reservoir, which orifice leads to a fluid passage of the tube. The support structure may comprise a plurality of protrusions that are arranged around the orifice and that extend from a base portion of the body portion. The invention also relates to a method of manufacturing a fluid reservoir for a penile implant device, which includes positioning a tube in a mold and injection molding a reservoir body onto the tube. More particularly, the method may include providing a mold, positioning a tube in the mold, injecting material into the mold, curing the material, and opening the mold to remove the reservoir body and tube assembly.

One common treatment for erectile dysfunction includes the use of a penile implant device. One type of penile implant device, commonly known as a three-piece device, includes a pair of inflatable cylindrical prostheses that are implanted into the corpus cavernosae of the penis, which are connected to a fluid-filled reservoir through a pump and valve assembly. Such a pump and valve assembly is typically implanted into the scrotum of the patient, and the reservoir is implanted in the abdomen. Tubing is used to connect each penile prosthesis to the pump, and additional tubing is used to connect the pump to the reservoir. To activate the penile implant device, the patient would typically actuate the pump using one of a variety of methods that cause fluid to be transferred from the reservoir through the pump and into the prostheses. This results in the inflation of the prostheses and produces rigidity for a normal erection. Then, when the patient desires to deflate the prostheses, a valve assembly within the pump is actuated in a manner such that the fluid in the prostheses is released back into the reservoir. This deflation returns the penis to a flaccid state.
The reservoir used in these three-piece systems is usually in the form of a flexible bag or bladder that can expand and contract in volume with movement of fluid to and from the reservoir. One commonly used method for manufacturing these reservoirs is by a dip coating process. Dip coating consists of introducing a mandrel of a desired geometry into a self-leveling thermoplastic or thermosetting material (e.g., a silicone dispersion of a specific solids content and viscosity). Much like old-fashioned candle making, the mandrel is repeatedly dipped into the dispersion until a desired wall thickness is obtained for the part. A period of time (e.g., 15 to 20 minutes) can be required between successive dipping processes to allow the previous coat of material to set sufficiently before initiating the next successive dip cycle. In the case of a spherical reservoir, for example, 24 to 28 dip cycles may be required to obtain a suitable wall thickness.
After a desired wall thickness is achieved, the reservoir produced by the mandrel coating process may be subjected to additional processing steps, such as placement in an oven for a curing process, for example. Curing is a step that is typically used in a process of preparing a thermosetting (e.g., silicone) reservoir body of a penile implant device. In some cases, an oven curing process can take a significant amount of time, such as 6 to 8 hours. After the curing process is complete, the coated mandrel is removed from the oven and allowed to cool to room temperature. The cured reservoir is then manually removed from the mandrel to complete the process. The total time from start to finish for a dip coating process can be 24 hours or more, and can be very costly and labor intensive. In addition, the dip coating process can require a relatively large manufacturing area, particularly when many reservoirs are being manufactured simultaneously.
The materials used for making reservoirs by dip-coating processes can also be expensive and time consuming to prepare, which further increases the cost and timing of producing a dip-coated implantable reservoir. One example of a material that is sometimes used in these dip-coating processes is a silicone dispersion that is a two-part platinum cure dispersion dispersed in xylene to convert from a semi-solid to a self-leveling liquid state. Preparation of the dispersion before it can be used for a dip-coating process can take 24 hours or longer, including the time required for mixing and de-airing. For manufacturing efficiency, the batches of material are generally made in relatively large quantities, which are usually very expensive. The effective cost of the dispersion further increases in cases where a portion of the dispersion is unused and must be discarded after its predetermined usable life.
The production of dip-coated implantable reservoirs also can be relatively complicated due to the number of parts and bonds required to incorporate the reservoir into a device that can be used in a prosthesis device. As an example, four components are often used to produce a typical dip coated reservoir assembly. These components include a molded silicone shell adapter, a silicone stand pipe, a dip coated reservoir shell, and section of kink resistant tubing. In this reservoir assembly, each of the individual components is bonded to an adjacent component using a suitable adhesive, such as a medical grade silicone adhesive. Each time a bond is made, an air (ambient) cure is performed, which generally take at least thirty minutes or longer, and which is followed by an oven cure generally for sixty minutes or longer before proceeding to the next bonding operation, thereby resulting in a process that is relatively slow, and time consuming. Thus, it is desirable to produce reservoir assemblies by methods and materials that are less costly than the production of reservoir assemblies using the dip coating and bonding methods described above.

Fluid reservoirs for penile implant devices and methods of manufacturing


A valve timing control device for controlling the opening/closing timing of the intake valve or exhaust valve incorporates a valve opening/closing rotary shaft, a rotor provided on the rotary shaft, a timing pulley for receiving rotational power from a crank pulley through a timing belt, a rotation transmitting member provided within the timing pulley and mounted around the rotary shaft to rotate within a predetermined range, a plurality of vanes provided on the rotor or the rotation transmitting member, a fluid chamber formed between the rotor and the rotation transmitting member and separated into advancing chambers and delaying chambers by the vanes, a first fluid passage communicating with the advancing chambers, a second fluid passage communicating with the delaying chambers, and a cooling mechanism for cooling the rotation transmitting member and/or the timing pulley.

1. Field of the Invention
The present invention relates to a valve timing control device to be used for controlling the opening/closing timing of an intake valve or an exhaust valve in a valve actuating mechanism of an internal combustion engine.
2. Description of the Related Art
In Unexamined Published Japanese Patent Application No. Hei 1-92504 or Unexamined Published Japanese Utility Model Application No. Hei 2-50105, for example, there is disclosed a valve timing control device of that kind comprising: a valve opening/closing rotary shaft rotatably assembled with the cylinder head of the internal combustion engine; a rotor integrally provided on the rotary shaft; a timing pulley for transmitting rotational power from a crank pulley through a timing belt; a rotational transmitting member integrally provided within the timing pulley, which is mounted around the peripheral surface of the rotary shaft, so as to rotate within a predetermined range for transmitting the rotational power from the crank pulley; a plurality of vanes provided on the rotor or the rotational transmitting member; a fluid chamber formed between the rotor and the rotational transmitting member and separated into advancing chambers and delaying chambers by the vanes; first fluid passages for feeding and discharging a fluid to and from the advancing chambers; and second fluid passages for feeding and discharging the fluid to and from the delaying chambers.
In the valve timing control device, as described in each of the above-cited patent applications, the rotational transmitting member includes an external rotor, a front plate and a rear plate. The fluid chamber is formed between the rotor and the external rotor and separated into advancing chambers and delaying chambers by the vanes. Working fluid is fed to or discharged from the advancing chambers and delaying chambers. The timing pulley is disposed outside of the external rotor.
The timing belt is located between the crank pulley and the timing pulley. The timing belt, the crank pulley and the timing pulley are all disposed in a timing belt case. The timing belt case is attached on the side of the cylinder block and on the front side of the cylinder head. When the internal combustion engine is driven, the temperature of the atmosphere inside the timing belt case reaches about 80 degrees centigrade. On the other hand, the working fluid, which is used as lubricating oil, reaches from about 120 degrees centigrade to 130 degrees centigrade, when the internal combustion engine is driven. In the valve timing control device, as described in each of the above-cited patent applications, the working fluid heats the rotational transmitting member and the timing pulley. This heat might damage the timing belt made of a resin or a rubber and shorten the lifespan of the timing belt.


A conveyor system transports a multiplicity of product items from an input portion to an output portion and is provided with a first conveyor that transports the product items from the input portion to a distal turnaround region. A second conveyor transports the product items from the distal turnaround region to a redistribution region. A first product transfer arrangement urges the product items from the first conveyor to the second conveyor. A plurality of exit conveyors are arranged to be parallel to each other for transporting the product items from the redistribution region to a product exit region located at the output portion, and are arranged to transport the product items at a respectively associated rates of transport. A product redistribution arrangement directs the product items to respective input ends of the plurality of exit conveyors. There is additionally provided a transverse element for directing the product items on the plurality of exit conveyors to a predetermined one of the plurality of exit conveyors.

1. Field of the Invention
This invention relates generally to conveyor systems, and more particularly, to an accumulating conveyor system that expels batch loaded product items in one or more single file outlet channels and accumulates the excess product items in response to the quantity of such product items being transported on plural exit conveyors.
2. Description of the Related Art
There are plural problems in the present state of the art in the field of conveyor systems that are used to deliver product items to downstream equipment, particularly in environments where the product items are delivered at varying rates, or in batches, to the conveyor system. It is, in those situations, not only desired that the conveyor system accumulate the excess product items pending their discharge, but also that the discharge of product items be in a continuous flow of back-to-back product items in single file. It is desired that accumulation of product items in the conveyor system be increased in the event of interruption in the downstream equipment or in the event that the inflow exceeds the desired discharge rate. All this, while maintaining proper orientation of non-round product items during discharge and without undue bumping between the product items, as they may be formed of glass or otherwise be fragile. In addition to minimizing product bumping, which is related to product back pressure, it is important that the product items not be subjected to undue rotation, as such may cause viscous liquid therein to be spun at a different rate that the container itself, resulting in a "gel wobble" instability and consequential toppling of the product items.
The various approaches to the noted problems in the prior art have proven unsatisfactory. Generally speaking, an effort to solve one problem exacerbates another, or creates a new problem. More specifically, in one known arrangement conveyor belts traveling at the same speed transport product items operate in conjunction with a guide that allows the product items to be moved from upstream to downstream locations during operation, and directs the product items to the accumulator section. In addition to requiring a large recirculating area by virtue of its continuous conveyor belt approach to achieving product item accumulation, the known arrangement does not redirect non-circular product items to a desired orientation in the exit port of the conveyor system. Thus, product items having elongated cross-section may temporarily block the exit port, resulting in a single file exit having gaps. In addition, the known arrangement is noisy in its operation as product items are directed to the accumulation area by bumping into product items that are to be discharged and thereby are deflected to the accumulation area. Accumulation capacity is almost exclusively a function of accumulation conveyor belt width in known systems. Thus, increases in accumulation capacity are effected by increasing conveyor belt width, which is achieved at the expense of mechanical complexity in causing belts of increasing width to be curved to form a substantially closed accumulation loop.
Some of these problems have been addressed by other known system. In one such system, a mass of product items is combined into a single file lane by using a moving guide belt disposed over a plurality of parallel conveying surfaces that travel at progressively increasing speeds. The object of the known arrangement, which requires multiple levels of conveyor belts, is to minimize rotation of the product items being conveyed. The product items, which traditionally are guided by stationary guide rails across belts having increasing relative speeds, are known to be rotatable at a speed of rotation that is a function of the rate of linear transport. Product rotation is reduced by forming a guide that is itself in the form of a guide belt, as a substitute for the stationary guide rails. The guide belt is caused to communicate with the product items at an angle and a speed with respect thereto that the rotation is minimized. Significant mechanical complexity and expense are associated with this known approach.
It is, therefore, an object of this invention to provide an accumulating conveyor arrangement that orients product items to conform to a desired exit orientation.
It is another object of this invention to provide an accumulating conveyor arrangement that reduces product bumping.
It is also an object of this invention to provide an accumulating conveyor arrangement that reduces product instability and toppling.
It is a further object of this invention to provide an accumulating conveyor arrangement that provides minimal product back pressure during either accumulation or straight-through discharge of the product items.
It is additionally an object of this invention to provide an accumulating conveyor arrangement that does not rely on curved closed loop conveyor belting to achieve product accumulation.
It is yet a further object of this invention to provide a conveyor system that does not rely on product back pressure to effect single file product discharge.


A specific amount of a low molecular weight vinyl siloxane is blended with a platinum-vinyl siloxane complex to provide a platinum complex catalyst, which is prevented from deterioration with time at elevated temperatures and from blackening and precipitation, and maintains its catalytic activity unaffected.

1. Field of the Invention
This invention relates to a platinum complex catalyst in the form of a modified platinum-vinyl siloxane complex having improved storage stability and useful as a hydrosilylation catalyst.
2. Prior Art
Hydrosilylation reaction represented by the following scheme is well known in the art and finds application in a variety of areas using curable silicone compositions. ##STR1##
This hydrosilylation reaction is to react SiH group-bearing compounds such as organohydrogensiloxane with CH.sub.2 .dbd.CH group-bearing compounds such as vinyl-bearing organopolysiloxanes in the presence of platinum catalyst. Of the platinum catalysts, initial ones are halogenated platinum compounds and microparticulate metallic platinum, for example, chloroplatinic acid disclosed in Speir, U.S. Pat. No. 2,823,218 and platinum-carrying char coal disclosed in Bailey, U.S. Pat. No. 2,970,150. From the standpoint of economical efficacy, efforts were made to improve the activity of catalysts. Since then, platinum-vinyl siloxane complexes have been frequently used. However, it is pointed out in JP-B 423/1980 that halide ions in platinum-vinyl siloxane complexes adversely affect the catalytic activity thereof. JP-B 28795/1971 and 23679/1972 disclose that platinum-vinyl siloxane complexes can be decomposed upon contact with water. It was thus recommended that platinum-vinyl siloxane complexes are stored at temperatures between 50.degree. C. and 50.degree. C.
However, we often encountered the phenomenon that platinum-vinyl siloxane complexes blackened and settled in summer. This phenomenon causes a trouble during storage and on subsequent use.
Efforts have also been made to improve the activity of platinum-vinyl siloxane complexes by minimizing the content of residual halide. For example, JP-A 136655/1981 discloses a platinum complex substantially free of inorganic halides. In contrast, JP-A 36573/1991 discloses a method for preparing a platinum-vinyl siloxane complex having high activity and storage stability even when more than 1 gram-atom of inorganic halide is present per gram-atom of platinum. We confirmed that the hydrolysilation catalyst obtained by this method lacked storage stability at elevated temperatures, blackened its outer appearance, gradually formed precipitates, and invited a decline of its catalytic activity.
Therefore, it is desired to overcome the above-mentioned problems during storage of platinum-vinyl siloxane complexes that they are sensitive to heat and moisture, lack storage stability, and tend to decrease their catalytic activity through coloring and formation of black precipitates, especially in summer. That is, it is desired to improve the storage stability of platinum-vinyl siloxane complexes without lowering their catalytic activity.


The ground anchors of the type which are attached to cables, rods and the like, which are driven into the ground and tilted transversely of the hole by tensioning the cable are provided. A ground anchor including a central hollow tubular body portion extending substantially along the length of the anchor and a pair of laterally projecting wings extending from opposing sides of the body portion, wherein the wings are bent at an angle to the horizontal plane, and a portion of an edge of each wing is bent at an angle to the plane of the wing.

1. Field of the Invention
The invention relates to ground anchors of the type which are attached to cables, rods and the like, which are driven into the ground and tilted transversely of the hole by tensioning the cable.
2. Description of Related Art
A variety of ground anchors already exist including tubular anchors, such as those described in GB-A-1555580 and EP-A-0208153. These anchors are driven into the ground and then rotated to a horizontal locked position. As the surface area of these anchors is not particularly large, they are not appropriate for some uses where a particular degree of strength and resistance to removal from the ground is required.
Improvements have been made to such anchors which resulted in the addition of wings to provide a greater planar or surface area to resist the anchors from being pulled from the ground once in their tilted locked position. Examples of such wing anchors are known from EP-A-0313936, U.S. Pat. No. 4,574,539 and U.S. Pat. No. 3,282,002. Each of these anchors has different specific features which enable the anchors either to be easily driven into the ground, to prevent its withdrawal therefrom, or to ease the ability to rotate the anchor once embedded in the ground.


A method and apparatus for programming instruction issuing rules for instructions residing among various virtual channels, as well as the same virtual channel of an I/O bus interface for a system-on-a-chip processor. In the method and apparatus of the present invention both intra-virtual channel dependencies and inter-virtual channel dependencies are fully programmable, thereby offering significant advantages over prior art I/O interfaces. The method and apparatus of the present invention is broadly comprised of a system for managing data transactions between a first bus and a second bus. A first transaction conversion module is operably connected to the first bus and is operable to receive transactions from the first bus and a first format and to convert those transactions into an internal format. An ordering rules logic module is operably connected to the first transaction conversion module and is further operable to control issuing of transactions in accordance with a dependency relationship between the individual transactions. The ordering rules logic module generates validated transactions that are provided to a second conversion transaction module which is operably connected to the second bus. The ordering rules logic module of the present invention is fully programmable and, therefore, does not need to be redesigned when the data processing system is adapted to operate on a new bus system.

1. Field of the Invention
The present invention is directed in general to data communications. More specifically, the present invention provides an improved method and apparatus for controlling the transfer of information between various buses in high speed data processing systems.
2. Related Art
As is known, communication technologies that link electronic devices are many and varied, servicing communications via both physical media and wirelessly. Some communication technologies interface a pair of devices, other communication technologies interface small groups of devices, and still other communication technologies interface large groups of devices.
Examples of communication technologies that couple small groups of devices include buses within digital computers, e.g., PCI (peripheral component interface) bus, ISA (industry standard architecture) bus, USB (universal serial bus), and SPI (system packet interface). One relatively new communication technology for coupling relatively small groups of devices is the HyperTransport (HT) technology, previously known as the Lightning Data Transport technology (HyperTransport I/O Link Specification "HT Standard"). The HT Standard sets forth definitions for a high-speed, low-latency protocol that can interface with today's buses like AGP, PCI, SPI, 1394, USB 2.0, and 1 Gbit Ethernet as well as next generation buses including AGP 8x, Infiniband, PCI-X, PCI 3.0, and 10 Gbit Ethernet. HT interconnects provide high-speed data links between coupled devices. Most HT enabled devices include at least a pair of HT ports so that HT enabled devices may be daisy-chained. In an HT chain or fabric, each coupled device may communicate with each other coupled device using appropriate addressing and control. Examples of devices that may be HT chained include packet data routers, server computers, data storage devices, and other computer peripheral devices, among others.
Many programming tasks, especially those that control peripheral devices require specific events to occur in a specific order. If the events generated by the program do not occur in the hardware in the order intended by the software, a peripheral device may behave in an unexpected way. Ordering or dependency rules are necessary for the correct operation of an IO bus system. However, ordering rules for one IO bus standard may not be compatible with those for another bus. Designing for a new IO bus interface for a System-On-a-Chip processor often involves re-design of the ordering rules logic section for the bus interface. There is a need, therefore, for an improved bus interface system that provides rule ordering logic that is programmable and, therefore, does not need to be redesigned when the interface is adapted to a new bus system.

Programmable inter-virtual channel and intra-virtual channel instructions issuing rules for an I/O bus of a system-on-a-chip processor


To estimate a distribution of voltages or currents in the layers of a multi-layer circuit, an exemplary current flow in each layer is discretized into a number of current vector elements and at least one scalar charge element related to the charge associated with each current vector element. A first distribution of voltages induced in each circuit layer is determined from current vector elements in all of the circuit layers. A second distribution of voltages induced in each circuit layer is determined from the scalar charge elements in all of the circuit layers. For each circuit layer, the first and second distributions of voltages induced therein are combined to determine an actual distribution of voltages in the circuit layer.

1. Field of the Invention
The present invention relates to the design of multi-layer circuits, e.g., integrated circuits or printed circuits, and, more particularly, to determining the electromagnetic effects on the performance of the circuit from a bias applied to the multi-layer circuit.
2. Description of Related Art
As the size of electrical devices and interconnecting conductors of multi-layer circuits, especially multi-layer integrated circuits, continues to decrease and the bandwidth of operation continues to increase, the effects on the performance of the circuit due to electromagnetic effects in the various layers of the circuit have become more pronounced.
Heretofore, analysis of such effect on each circuit layer was limited to evaluating such effect due to current flowing only in the layer itself. See for example, "An Efficient Algorithm For Analyzing Large-Scale Microstrip Structures Using Adaptive Integral Method Combined With Discrete Complex-Image Method", by Ling et al., IEEE Transactions On Microwave Theory And Techniques, Vol. 48, No. 5, pp. 832–839, (May 2000); "AIM: Adaptive Integral Method For Solving Large-Scale Electromagnetic Scattering And Radiation Problems", by Bleszynski et al., Radio Science, Volume 31, Number 5, Pages 1225–1251, (September–October 1996); and "A Precorrected-FFT Method For Electrostatic Analysis Of Complicated 3-D Structures", by Phillips et al., IEEE Transactions On Computer-Aided Design Of Integrated Circuits And Systems, Vol. 16, No. 10, pp. 1059–1072, (October 1997).
While this approach has been applied successfully in the past, the increasing density of devices and the reduction in size of interconnecting conductors in the design of multi-layer circuits require that the effects on the performance of the circuit due to the cumulative effects of currents flowing in all of the layers of the circuit be considered.
What is needed, however, and not disclosed in the prior art is a method and apparatus for determining the effects on the performance of a multi-layer circuit, such as an integrated circuit or a multi-layer printed circuit board, due to currents flowing in all of the layers of the circuit in a computationally efficient and time-effective manner. It is also desirable that such method and apparatus have a predictable degree of accuracy.

Method and apparatus for determining interactive electromagnetic effects among conductors of a multi-layer circuit


Wiring structures of three-dimensional semiconductor devices and methods of forming the same are provided. The wiring structures may include an upper wordline and a lower wordline, each of which extends in a longitudinal direction. The upper wordline may include a recessed portion that extends for only a portion of the upper wordline in a transverse direction and the lower wordline may include a wiring area exposed by the recessed portion of the upper wordline. The wiring structures may also include an upper contact plug contacting the upper wordline and a lower contact plug contacting the wiring area. The upper and lower contact plugs may extend in a vertical direction.

Recently, three-dimensional semiconductor devices have been developed to manufacture highly integrated devices. Since three-dimensional semiconductor devices may have a stacked structure of memory cells in a vertical direction, electric signals may be applied to each of the cells stacked in the vertical direction. Therefore, three-dimensional semiconductor devices may have a complicated wiring structure.

Wiring structures for three-dimensional semiconductor devices


Provided is a push/press switch design which allows for a reduced total height profile while maintaining a smooth operation with a large operation stroke by suppressing an extremely large sliding friction when a corner portion of a stem is pressed.

1. Field of the Invention
The present invention relates to a switch which is operated by a pressing operation, and more particularly to a switch structure capable of smoothly performing a pressing operation with a suitable load at a large operation stroke even when a total height of the switch is small.
2. Description of Related Art
Miniaturization of switches, particularly push/press switches places an ever increasing demand on dimensional requirements (e.g., height requirements, etc.). In turn, such miniaturization affects performance of conventional switches due to minimum required distances between, for example, two contact surfaces, a stroke distance, etc. Accordingly, there remains a need for smaller or miniaturized push/press switches that still maintain integrity of operation.


An efficient and reconfigurable permanent magnet generator that comprises a permanent magnet subassembly and at least one exciter is disclosed. The permanent magnet generator may comprise a mainframe comprising at least one exciter, and a permanent magnet subassembly comprising a plurality of magnets that are arranged to form at least one air gap between facing magnetic poles in which the at least one exciter resides and that are reconfigurable for alternating current or direct current operation by inversion of respective magnetic poles. The at least one exciter may comprise a plurality of alternating layers of a first material and a second material, where the first material may comprise a superconductive material and the second material may comprise a non-superconductive material, and wherein the layers of the superconductive material are thin relative to the thickness of the layers of the non-superconductive material. A method for generating electric energy using a reconfigurable permanent magnet generator is also disclosed. The method comprises selecting an alternating current or a direct current generation mode; configuring at least one reconfigurable magnet to correspond with the selected generation mode; disposing at least one exciter in an air gap defined by the at least one reconfigurable magnet; and

In simple terms, a generator is a device for converting mechanical energy into electrical energy and works by electromagnetic induction. A power source drives a coil winding, causing it to rotate between the poles of a permanent magnet or electromagnet. As the coil winding spins and cuts through the lines of force between the poles of the magnet, potential energy and electric current is generated and flows through the coil winding. The electric current that is generated may be either direct current (DC) or alternating current (AC). In AC generation, a sinusoidal output waveform is produced; no energy is induced as the coil winding rotates parallel to the magnetic flux lines, while maximum power is achieved when the coil winding is rotating tangential to the magnetic flux lines.
The first electric generators, or dynamos, were modeled and built in the 1830s. By the end of the nineteenth century, significant advances were being made in the field of electrical generation, particularly by Nikola Tesla. In 1890, Tesla disclosed a pyromagneto-electric generator in U.S. Pat. No. 428,057, in which he recognized that the magnetic properties of iron and other magnetic substances may be compromised by raising the material to a certain temperature and restored by again lowering the temperature. Also in 1890, Tesla disclosed an electrical transformer or induction device in U.S. Pat. No. 433,702.
Alternating current generators in use at the time typically provided from one to three hundred alterations of current per second. It was soon recognized that higher rates of alteration would be an advantage. Producing higher rates of alteration with generator designs at the time, however, was difficult and resulted in decreased efficiency, primarily due to high magnetic leakage, and improved generator designs were sought. In U.S. Pat. No. 447,921, Tesla discloses a field-magnet core made up of two independent parts formed with grooves for the reception of one or more energizing coils. The energizing coils are completely surrounded by the iron core, except on one side, where there is a narrow opening between the polar faces of the core, and the polar faces of the core are formed with many projections or serrations. This field-magnet design produced less magnetic leakage but still did not operate at a desired level of efficiency.
In 1894, Tesla disclosed an electric generator in U.S. Pat. No. 511,916. This generator was capable of continued production of electric currents of constant period by imparting the movements of a piston to a core or coil in a magnetic field.
By the twentieth century, more reliable turbines were in use, capable of providing 50-60 Hertz power with 3000-3600 alternations of current per second. In U.S. Pat. No. 1,061,206, Tesla discloses a turbine that improves the use of fluids as motive agents by causing a propelling fluid to move in natural paths or stream lines of least resistance, avoiding losses due to sudden variations while the fluid is imparting energy. This method, when coupled with power generating equipment, provided a more efficient and reliable means of hydraulic power synthesis.
Another conventional generator example is the Detroit Edison generator. The Detroit Edison generator includes an outer extruded stationary permanent magnet with opposite magnetic poles forming an air gap at the center, with a number of windings rotated within the air gap to induce current in the rotating windings. As with other early generator designs, increased and improved efficiency was sought, often realized by increasing the length of the cylindrical generator.
Generator designs continued to advance in the twentieth century, where improvements made to the above-identified generator designs frequently focused on improving efficiency. U.S. Pat. No. 3,538,364, to Favereau, discloses a rotary electric machine comprising a fixed primary stator in the form of a pair of concentrically arranged inner and outer stator elements having magnetic poles and between which, in an air gap, the secondary cylindrical rotor having a winding thereon is mounted for rotation. The magnetic stator provides a 360-degree air gap between opposite magnetic poles in the inner and outer stator. This arrangement reduced the size of leakage fluxes and reduced the volume of the coils situated around the poles, permitting increases in the working induction in the cylindrical air gap.
More recently, improvements have recognized and addressed optimizing the waveshape of the generator output to maximize generator output and improve efficiency. In U.S. Pat. No. 5,650,680, Chula discloses a permanent magnet generator having a rotor including a plurality of permanent magnets generating an operative magnetic flux field, seeking to create an output voltage signal with reduced harmonic content.
Conventional generator designs typically include contacts, or "brushes," that rotate relative to electrical contacts and provide a circuit for electricity to flow through. Brushes, however, require regular maintenance and replacement as they become worn. Additionally, the electrical resistance of the brushes and the mechanical frictional loss between the brushes and the contacts decrease generator efficiency. These drawbacks were recognized by Rakestraw et al. in U.S. Pat. No. 5,696,419, which discloses an electrical generator with a plurality of C-shaped stator members made of magnetically permeable material. A flat ring-shaped rotor defines a periphery, and a plurality of permanent magnets are positioned around the periphery. The rotor is positioned with the magnets of the rotor disposed in the gap defined by the stator members, so that when the rotor is rotated by a prime mover to move the magnets through the gap, an electrical current is induced in the stator windings.
Others have sought to improve generator efficiency by not only eliminating brushes but also improving per-magnet rotor excitation. In U.S. Pat. No. 6,462,449, Lucidarme et al. disclose a rotating electric machine where the rotor includes a magnetic field core provided with radial teeth, uniformly distributed at its periphery. Annular magnets are arranged on either side of the core axial ends and magnetic end flanges pressing the annular magnets against the core. Magnetic bars link the end between each of the bars and at least the side walls of the core radial teeth defining the spaces. The stator includes a magnetic core, excitation coils arranged on either side of the core, a stator coil wound on the core, and a magnetic ring in contact with the core and provided with radial rims cooperating with the axial rims of the rotor end flanges to form paths for the return flux.
While generator efficiencies have been increased through mechanical and electrical engineering methods as described above, there is still room for significant advancement and improvement. Relatively recent advancements in modern materials science have been applied to generator design and manufacture. For example, superconductive materials have been used in the construction of generator components. These materials provide a reduced resistance to the flow of electricity, and when used in generator components, superconductive materials have been shown to increase overall efficiency on the order of approximately 1%-3% in some applications, a relatively small gain that is quickly appreciated in large-scale generators.
An example of a trapped-field superconducting generator is disclosed in U.S. Pat. No. 5,325,002, to Rabinowitz et al. This motor/generator includes superconductive material in either the stator or the rotor and a magnetic field generator is included in the other of these two members. Induced fields in a torque-shield provide coupling between the stator and the rotor during the start-up phase of the motor/generator, and then a trapped field in the superconductor provides coupling between the stator and rotor thereafter.
U.S. Pat. No. 6,169,352, to Hull, discloses another example of a trapped-field superconducting motor generator. The motor generator includes a high temperature superconductor rotor and an internally disposed coil assembly. The motor generator superconductor rotor is constructed of a plurality of superconductor elements magnetized to produce a dipole field. The coil assembly can be either a conventional conductor or a high temperature superconductor. The superconductor rotor elements include a magnetization direction and c-axis for the crystals of the elements and which is oriented along the magnetization direction.
The above-identified generators are typically bulky and complex. Further, their designs are static, producing a single output and requiring manufacturing retooling to produce an alternate output form. Additionally, even in conventional superconducting generators, increased efficiency is desired, particularly by large-scale generation facilities and public utilities, where a small increase in efficiency can lead to a significant cost savings over time.
Therefore, there is a need for a cost-effective generator that operates with increased efficiency. There is also a need for a generator that is reconfigurable, capable of producing multiple desired outputs from a single tooled design. There is also a need for a generator that is capable of producing outputs over longer periods of time, with greater reliability and reduced maintenance costs. Further, there is a need for a generator that is adaptable to a greater range of inputs, i.e. combustion, nuclear, wind, water, and other renewable energy resources.

Abstract: rotating the at least one reconfigurable magnet relative to the at least one exciter. The disclosed generator may thus produce either alternating current (AC) or direct current (DC) using alternative configurations of the same mechanical components.


A system and method includes deploying first and second articulated arms of a computer-assisted device so that a first attachment point on the first articulated arm and a second attachment point of the second articulated arm are positioned and oriented relative to each other based on a size and a shape of an arm stabilizer; stabilizing and reducing vibration of the first and second articulated arms by attaching the arm stabilizer to the first and second attachment points; after the stabilizing and reducing vibration of the first and second articulated arms, positioning and orienting a tool with the first articulated arm; and after the positioning and orienting of the tool, operating the tool. In some embodiments, the tool is a medical tool. In some embodiments, the system and method further include positioning and orienting a second tool with the second articulated arm and operating the second tool.

More and more devices are being replaced with autonomous and semiautonomous electronic devices. This is especially true in the hospitals of today with large arrays of autonomous and semiautonomous electronic devices being found in operating rooms, interventional suites, intensive care wards, emergency rooms, and the like. For example, glass and mercury thermometers are being replaced with electronic thermometers, intravenous drip lines now include electronic monitors and flow regulators, and traditional hand-held surgical instruments are being replaced by computer-assisted medical devices.
These electronic devices provide both advantages and challenges to the personnel operating them. Many of these electronic devices may be capable of autonomous or semi-autonomous motion of one or more articulated arms, end effectors and/or imaging devices. When the articulated arms and/or the end effectors include redundant degrees of freedom (i.e., more than the six degrees of freedom typically associated with Cartesian x, y, and z positioning and roll, pitch, and yaw orientations), the articulated arms and/or the end effectors may provide extensive flexibility in adjusting to changes in patient size, position, and/or orientation as the articulated arms and/or the end effectors are used to support medical procedures. This is possible because the redundant degrees of freedom allow the articulated arms and/or the end effectors to be positioned so as to avoid collisions among themselves, the patient, and/or other devices and personnel in an operating room and/or interventional suite.
Many medical procedures call for high precision in the positioning, orientation, and/or stability of the medical tools and/or devices used to perform the procedures. Computer-assisted medical devices with articulated arms have been used for years to perform high precision medical procedures, with the vast majority of these procedures being performed in the abdomino-pelvic cavities of the patient. There are many reasons for this including the large variety of possible abdomino-pelvic procedures and the characteristics of the anatomy of the abdomino-pelvic region, just to name a few. In some cases, a contributing factor may also be related to the realistic limitations of the computer-assisted medical devices and their articulated arms. In some examples, an articulated arm may have a practical upper limit on the amount of force and/or torque that the articulated arm may exert on a tool tip or end effector located at the distal end of the articulated arm due to such factors as the length of the articulated arm, the mass of the tool tip and/or end effector, the size of the actuators of the articulated arm, and/or the like. In some examples, the electro-mechanical systems of the articulated arm, the end effector, and/or the tool tip may also be subject to small oscillations and/or vibrations that may result in less than desirable vibrations in the tool top and/or the end effector. In some examples, the oscillations or vibrations may vary based on the mass of the end effector, tool tip, and/or imaging device located at the cantilevered end of the articulated arm and/or the position of the articulated arm.
In many circumstances, laparoscopic procedures with manually operated laparoscopic instruments may be subject to similar limitations. In many cases, a patient may introduce additional conditions that a stand-alone teleoperated system may not have. In some examples, physiological motions associated with respiration, heart beats, and/or the like may introduce motion to the end effector, tool tip, and/or imaging device that may be less than desirable as well.
During some procedures, the operator of the computer-assisted medical device may be able to suitably compensate for the oscillations and/or vibrations as long as the amplitude and/or frequency are not too large. In some examples, compensating for the oscillations and/or vibrations may significantly increase the fatigue of an operator.
In general, however, the limitations of the computer-assisted medical device and its articulated arms may be reduced and/or substantially eliminated during abdomino-pelvic procedures because of how the tool tips, end effectors, and/or imaging devices (such as an endoscope) pass through the body wall of the patient. During many procedures, the tool tips, end effectors, and/or imaging devices are passed through a hollow cannula that is inserted through an incision in the patient. The skin and the abdominal wall of the patient act on the cannula to both stabilize the tool tips, end effectors, and/or imaging devices and to absorb the vibrations. For minimally invasive medical procedures where there is a non-compliant body wall supporting the cannula (e.g., through the ribs in cardiac and thoracic procedures), a non-circumferential retainer on the cannula (e.g., procedures where multiple cannulas go through the same larger incision, such as transaxial thyroidectomy), a thin or frail body wall (e.g., pediatric or elderly patients), or no constraint/body wall at all (e.g., transoral, transanal, transvaginal, eye surgery, or extremity reconstructive procedures) the body wall alone may not be able to provide sufficient stabilization and/or vibration absorption to support many medical procedures where precision is important.
Stabilization and/or vibration reduction may be improved through the use of tool jigs that are attached to the patient or surgical table, mounted on table-side stands, mounted to ceiling fixtures, and/or the like. Many of these tool jigs, however, may have limitations in their degrees of freedom, size, and/or the like that significantly limit their ability to be used with patients of different sizes, different positions within the anatomy of the patients, interacting with different ancillary equipment, and/or with different procedures. These tool jigs may also have a limited ability to adapt to changes in patient position and/or orientation during a procedure. Additional flexibility may be obtained by using different tool jigs for different procedures, but the number of possible patients, positions, and/or procedures may involve an unacceptably large number of tool jigs.
Accordingly, it would be advantageous to develop systems and methods for vibration reduction and stabilization of the articulated arms, end effectors, and/or tool tips of computer assisted medical devices.

System and method for articulated arm stabilization


A control apparatus of a zoom lens is disclosed which automatically and accurately performs flange focal distance adjustment with a simple structure in a zoom lens of a rear focus type. The control apparatus comprises a memory which stores in-focus position data of a second lens unit with respect to the position of a first lens unit which provides variable magnification. A controller sets a reference position of the second lens unit for position control of the second lens unit with the in-focus position data based on an in-focus position of the second lens unit for an object at anywhere from the minimum object distance to the infinite distance when the first lens unit is located at the wide-angle end.

1. Field of the Invention
The present invention relates to a zoom lens control apparatus, a zoom lens system, and an image-taking system which uses the zoom lens control apparatus.
2.Description of Related Art
When a zoom lens is mounted on a television camera or a video camera, it is necessary to adjust a flange focal distance to match the position of an image plane to the position of the image-pickup device (such as a CCD) of the camera. The flange focal distance means a distance from a plane of the camera (a flange plane) on which the zoom lens is mounted, to the image plane of the zoom lens.
If the flange focal distance deviates from an appropriate value, disadvantages occur such as an image blur caused from zooming even when an image of a stationary object is taken. Especially in a zoom lens apparatus of a rear focus type which achieves focusing by a lens located on the side of a stop (diaphragm) closer to an image plane, a data table which includes a moving track of the rear focus lens on an optical axis (a zoom tracking curve) is previously stored in a memory for each object distance such that an in-focus state can be maintained by moving the rear focus lens in electric synchronization with zooming.
In such a zoom lens of the rear focus type, the flange focal distance needs to be adjusted to match a reference position in the data table to the position of the rear focus lens in order to allow accurate focusing.
Japanese Patent Application Laid-Open No. H7-154667 (No. 1995-154667) has proposed a method of adjusting a flange focal distance by finding an inflection point of a zoom tracking curve as described above and then determining the positions of the wide-angle end and the telephoto end.
Japanese Patent Application Laid-Open No. H12-121911 (No. 2000-121911) has proposed a method of adjusting a flange focal distance in a lens system of a type with no inflection point on a zoom tracking curve as described above. Specifically, when a lens for varying the magnification is located at the designed wide-angle end and the designed telephoto end, focus positions are found at the respective zoom positions through automatic focusing control to determine actual adjustment values in a zoom direction and a focus direction from a previously prepared table.
Japanese Patent Application Laid-Open No. H11-127376 (No. 1999-127376) has proposed a method of automating adjustment of a flange focal distance in a zoom lens apparatus of a front focus type in which a focus lens and a back focal distance adjusting lens can be electrically driven to perform automatic focusing control.
In the flange focal distance adjusting methods proposed in Japanese Patent Application Laid-Open No. H7-154667 and No. 2000-121911, however, an appropriate object must be disposed at a specific distance in adjusting the flange focal distance. This places a restriction on the flange focal distance adjustment at the site of image-taking, and in addition, the accuracy of the flange focal distance adjustment may be reduced if the actual object distance deviates from the specific distance.
In the flange focal distance adjusting method proposed in Japanese Patent Application Laid-Open No. H11-127376, each of the focus lens and the back focal distance adjusting lens needs to be electrically driven. In addition, it is necessary to construct a system which allows automatic focus detection for each of the lenses, so that the resulting system has a complicated structure.

Zoom lens control apparatus, zoom lens system, and image-taking system


Various embodiments are described relating to sharing scanning operations among nodes in a wireless network, such as a WiMedia ultra-wideband (UWB) network. In an example embodiment, a message may be sent from a first node to one or more other nodes in a wireless network indicating that the first node is configured to perform a scanning operation on a wireless medium in substitution of scanning the wireless medium at the one or more other nodes. The wireless medium may be scanned, for example, by the first node to obtain scanning results for the one or more other nodes. The scanning results may be sent, for example, by the first node, to the one or more other nodes.

As wireless technology has advanced, a variety of wireless networks have been installed, such as cellular and other wireless networks. Some wireless networks are based upon the Institute of Electrical and Electronics Engineers (IEEE) 802.11 family of Wireless LAN (WLAN) industry specifications, for example. As another example, some wireless networks are based upon the Distributed Medium Access Control (MAC) for Wireless Networks industry specifications of the WiMedia Alliance, for example. For example, the WiMedia network protocol adaptation (WiNet) layer is a protocol adaptation layer (PAL) that builds on a WiMedia ultra-wideband (UWB) common radio platform to augment the convergence platform with TCP/IP services. A number of working groups are working to improve on this technology.
An example standard, for example, the Distributed Medium Access Control (MAC) for Wireless Networks of the WiMedia Alliance, defines a distributed medium access control (MAC) sublayer for wireless networks, and further specifies a wireless network structure that does not require an existing infrastructure for communication such as, for example, a WiMedia ultra-wideband (UWB) network.
Categories of example applications considered for such an example standard may include portable electronic devices intended to be carried by a user, home electronics equipment, and personal computers and peripherals. Example portable electronic devices may have specific requirements to support mobility and good power efficiency. Devices such as home electronics and computers may not be as mobile, and not as sensitive to power efficiency as such portable electronic devices. All of these devices may benefit from a zero-infrastructure environment.
An interval, for example, a periodic time interval may be used to coordinate frame transmissions between devices, for example, a superframe interval may be used which includes a beacon period followed by a data period. The beacon period may include multiple beacon slots which may be used by multiple devices to send beacons.
In an example network formed with fully distributed medium access coordination, logical groups may be formed around each device in the network to facilitate contention-free frame exchanges while exploring medium reuse over different spatial regions. These logical groups may include, for example, a beacon group and an extended beacon group, both of which may be determined with respect to an individual device. For example, a beacon group may include a set of devices from which a device receives beacons that identify the same beacon period start time (BPST) as the device. An extended beacon group may include a union of a device's beacon group and the beacon groups of all devices in the device's beacon group.
Example MAC protocol algorithms may attempt to ensure that no member of an extended beacon group transmits a beacon frame at the same time as the device. Information included in beacon frames may facilitate contention-free frame exchanges by ensuring that a device does not transmit frames while a neighbor of the device (e.g., another device in the device's beacon group) is transmitting or receiving frames.
When a device is enabled, it may scan one or more channels for beacons and select a communications channel. If no beacons are detected in the selected channel, the device may create its own beacon period (BP) by sending a beacon. If one or more beacons are detected in the selected channel, the device may synchronize its BP to existing beacons in the selected channel. The device may then exchange data with members of its beacon group using the same channel the device selected for beacons.
Each device may protect its and its neighbors' BPs for exclusive use of the beacon protocol. Thus, no transmissions other than beacons may be attempted during the BP of any device. A device may protect an alien BP, detected by reception of a beacon frame unaligned with the device's own BP, by announcing a reservation covering the alien BP in its beacon. Within the context of a particular beacon group, an alien beacon group may include one or more devices included in a beacon group that identify a beacon period start time (BPST) that is different from the particular beacon group.
An example WiMedia standard also defines a dynamic beaconing technique, which enables devices in a distributed network to maintain fast connectivity. Devices may maintain synchronization with each other by participating in a beacon period, for example, by each device sending its own beacon and listening to other devices' beacons once in each superframe (e.g., 65.536 ms). The rest of the time the devices may send data to each other or hibernate, or sleep.
If a group of devices moves into the range of another group of devices, the groups may need to synchronize to each other before connectivity from one group to another may be available for the devices, and before channel time reservations may be handled without collisions. A group of devices may thus be viewed as "one device" or "two or more devices participating in the same beacon group," for example, devices having the same beacon period start time (BPST).
Establishing synchronization between the groups may involve regular scanning activities. Scanning may be performed at a device by listening to the channel, for example, for at least the time associated with one superframe occasionally. The scanning may be repeated based on an expectation of the connectivity speed. For example, if one superframe time is scanned once every second, the new devices or groups of devices on the same communications channel may be found on average in half a second when they enter the operating range. Scanning may also be subdivided into shorter pieces, but the amount of the total scanning time may be significant for finding the new devices within the range.
The power consumption caused by regular scanning may be significant, especially for a battery-powered device. For example, a device may participate in a beacon period (e.g., for an activity time of 0.5 ms for a small number of devices in the beacon group) every superframe and may perform a superframe scan once every two seconds, for example, with no data exchange. The power consumption attributed to the scanning for this example is four times the power consumption attributed to the beaconing. Also, if the device hibernates, participating in only a small part of the beacon periods, the scanning may still be required, but the scanning operation may consume an even higher percentage of the whole power consumption of the device.