A shaker screen including a composite frame, a removable grid attached to the composite frame, and at least one filtering element attached to the removable grid is disclosed. A method including forming a composite frame, forming a removable grid, attaching at least one filtering element to the removable grid, and attaching the removable grid to the composite frame is disclosed. Additionally, a method for rebuilding a shaker screen, the method including removing a first screen assembly from a composite frame, the screen assembly having a removable grid and at least one filtering element, and attaching a second screen assembly to the composite frame is disclosed.

1. Field of the Disclosure
Embodiments disclosed herein relate generally to oilfield shakers. More particularly, embodiments disclosed herein relate to pre-tensioned screens for oilfield shakers.
2. Background Art
Oilfield drilling fluid, often called "mud," serves multiple purposes in the industry. Among its many functions, the drilling mud acts as a lubricant to cool rotary drill bits and facilitate faster cutting rates. Typically, the mud is mixed at the surface and pumped downhole at high pressure to the drill bit through a bore of the drillstring. Once the mud reaches the drill bit, it exits through various nozzles and ports where it lubricates and cools the drill bit. After exiting through the nozzles, the "spent" fluid returns to the surface through an annulus formed between the drillstring and the drilled wellbore.
Furthermore, drilling mud provides a column of hydrostatic pressure, or head, to prevent "blow out" of the well being drilled. This hydrostatic pressure offsets formation pressures thereby preventing fluids from blowing out if pressurized deposits in the formation are breeched. Two factors contributing to the hydrostatic pressure of the drilling mud column are the height (or depth) of the column (i.e., the vertical distance from the surface to the bottom of the wellbore) itself and the density (or its inverse, specific gravity) of the fluid used. Depending on the type and construction of the formation to be drilled, various weighting and lubrication agents are mixed into the drilling mud to obtain the right mixture. Typically, drilling mud weight is reported in "pounds," short for pounds per gallon. Generally, increasing the amount of weighting agent solute dissolved in the mud base will create a heavier drilling mud. Drilling mud that is too light may not protect the formation from blow outs, and drilling mud that is too heavy may over invade the formation. Therefore, much time and consideration is spent to ensure the mud mixture is optimal. Because the mud evaluation and mixture process is time consuming and expensive, drillers and service companies prefer to reclaim the returned drilling mud and recycle it for continued use.
Another significant purpose of the drilling mud is to carry the cuttings away from the drill bit at the bottom of the borehole to the surface. As a drill bit pulverizes or scrapes the rock formation at the bottom of the borehole, small pieces of solid material are left behind. The drilling fluid exiting the nozzles at the bit acts to stir-up and carry the solid particles of rock and formation to the surface within the annulus between the drillstring and the borehole. Therefore, the fluid exiting the borehole from the annulus is a slurry of formation cuttings in drilling mud. Before the mud can be recycled and re-pumped down through nozzles of the drill bit, the cutting particulates must be removed.
Apparatus in use today to remove cuttings and other solid particulates from drilling mud are commonly referred to in the industry as "shale shakers." A shale shaker, also known as a vibratory separator, is a vibrating sieve-like table upon which returning dirty drilling mud is deposited and through which clean drilling mud emerges. Typically, the shale shaker is an angled table with a generally perforated filter screen bottom. Returning drilling mud is deposited at the top of the shale shaker. As the drilling mud travels down the incline toward the lower end, the fluid falls through the perforations to a reservoir below leaving the solid particulate material behind. The combination of the angle of inclination with the vibrating action of the shale shaker table enables the solid particles left behind to flow until they fall off the lower end of the shaker table. The above described apparatus is illustrative of one type of shale shaker known to those of ordinary skill in the art. In alternate shale shakers, the top edge of the shaker may be relatively closer to the ground than the lower end. In such shale shakers, the angle of inclination may require the movement of particulates in a generally upward direction. In still other shale shakers, the table may not be angled, thus the vibrating action of the shaker alone may enable particle/fluid separation. Regardless, table inclination and/or design variations of existing shale shakers should not be considered a limitation of the present disclosure.
Preferably, the amount of vibration and the angle of inclination of the shale shaker table are adjustable to accommodate various drilling mud flow rates and particulate percentages in the drilling mud. After the fluid passes through the perforated bottom of the shale shaker, it can either return to service in the borehole immediately, be stored for measurement and evaluation, or pass through an additional piece of equipment (e.g., a drying shaker, centrifuge, or a smaller sized shale shaker) to further remove smaller cuttings.
Because shale shakers are typically in continuous use, any repair operations and associated downtimes are to be minimized as much as possible. Often, the filter screens of shale shakers, through which the solids are separated from the drilling mud, wear out over time and need replacement. Therefore, shale shaker filter screens are typically constructed to be quickly and easily removed and replaced. Generally, through the loosening of only a few bolts, the filter screen can be lifted out of the shaker assembly and replaced within a matter of minutes. While there are numerous styles and sizes of filter screens, they generally follow similar design. Typically, filter screens include a perforated plate base upon which a wire mesh, or other perforated filter overlay, is positioned. The perforated plate base generally provides structural support and allows the passage of fluids therethrough, while the wire mesh overlay defines the largest solid particle capable of passing therethrough. While many perforated plate bases are generally flat or slightly curved in shape, it should be understood that perforated plate bases having a plurality of corrugated or pyramid-shaped channels extending theracross may be used instead. In theory, the pyramid-shaped channels provide additional surface area for the fluid-solid separation process to take place, and act to guide solids along their length toward the end of the shale shaker from where they are disposed.
A typical shale shaker filter screen includes a plurality of hold-down apertures at opposite ends of the filter screen. These apertures, preferably located at the ends of the filter screen that will abut walls of the shale shaker, allow hold down retainers of the shale shaker to grip and secure the filter screens in place. However, because of their proximity to the working surface of the filter screen, the hold-down apertures must be covered to prevent solids in the returning drilling fluid from bypassing the filter mesh through the hold-down apertures. To prevent such bypass, an end cap assembly is placed over each end of the filter screen to cover the hold-down apertures. Presently, these caps are constructed by extending a metal cover over the hold down apertures and attaching a wiper seal thereto to contact an adjacent wall of the shale shaker. Furthermore, epoxy plugs are set in each end of the end cap to prevent fluids from communicating with the hold-down apertures through the sides of the end cap.
Typically, screens used with shale shakers are emplaced in a generally horizontal fashion on a generally horizontal bed or support within a basket in the shaker. The screens themselves may be flat or nearly flat, corrugated, depressed, or contain raised surfaces. The basket in which the screens are mounted may be inclined towards a discharge end of the shale shaker. The shale shaker imparts a rapidly reciprocating motion to the basket and hence the screens. Material from which particles are to be separated is poured onto a back end of the vibrating screen. The material generally flows toward the discharge end of the basket. Large particles that are unable to move through the screen remain on top of the screen and move toward the discharge end of the basket where they are collected. The smaller particles and fluid flow through the screen and collect in a bed, receptacle, or pan beneath the screen.
In some shale shakers a fine screen cloth is used with the vibrating screen. The screen may have two or more overlying layers of screen cloth or mesh. Layers of cloth or mesh may be bonded together and placed over a support, supports, or a perforated or apertured plate. The frame of the vibrating screen is resiliently suspended or mounted upon a support and is caused to vibrate by a vibrating mechanism (e.g., an unbalanced weight on a rotating shaft connected to the frame). Each screen may be vibrated by vibratory equipment to create a flow of trapped solids on top surfaces of the screen for removal and disposal of solids. The fineness or coarseness of the mesh of a screen may vary depending upon mud flow rate and the size of the solids to be removed.
A typical shaker is shown in FIG. 1. In typical shakers, a screen 102 is detachably secured to the vibrating shaker machine 100. With the screen or multiple screens secured in place, a tray is formed with the opposed, parallel sidewalls 103 of shaker 100. The drilling mud, along with drill cuttings and debris, is deposited on top of screen 102 at one side. Screen 102 is vibrated at a high frequency or oscillation by a motor or motors for the purpose of screening or separating materials placed on screen 102. The liquid and fine particles will pass through screen 102 by force of gravity and be recovered underneath. Solid particles above a certain size migrate and vibrate across screen 102 or screens where they are removed. Filtering elements attached to screen 102 may further define the largest solid particle capable of passing therethrough.
While there are numerous styles and sizes of shaker screens, shaker screens can generally be categorized as either a hook strip type or a pre-tensioned (rigid frame) type. Both types contain one or more layers of filtering element. A distinction between the two types is that the filtering element layers of a hook strip type are not fully tensioned until they are attached to the shaker while the filtering element layers of a pre-tensioned type are in tension before the screen is attached to the shaker.
Pre-tensioned screens usually include one or more filtering element layers that are attached to a supporting frame. The filtering element layers are stretched across- and then secured to the supporting frame. Typically, the frame is rigid and provides structural support for the filtering element layers while allowing the passage of fluids. The frame of a pre-tensioned screen may include crossmembers and/or transverse ribs and may be formed from any material known in the art. Among the materials commonly used to form frames are stainless steels and other metal alloys. Composite frames consisting of two or more materials are also common.
FIG. 2 is an exploded cutaway view of a typical prior art pre-tensioned composite screen 200. Composite frame 202 includes steel rods 204 forming a frame sub-structure surrounded by a plastic outer frame 206. Two filtering element layers 208 are attached to the top side 210 of composite frame 202.
Often, the first component of a composite shaker screen to wear out or otherwise become unusable is one or more of the filtering element layers attached to the supporting frame. Composite frames still in good condition are often discarded because a filtering element layer attached to the frame is worn. This practice wastes the resources that form the composite frame and is cost inhibitive.
Accordingly, there is a recognized need for shaker screen designs having a composite frame where the composite frame may be reused after one or more of the filtering element layers attached to the composite frame need to be replaced.

Injection molded grid for saving screen frames


A method for securely transmitting data from a sender computer system to a receiver computer system comprises receiving cleartext message by a first intelligent agent environment; splitting said message into a plurality of message fragments; creating an intelligent agent for each message fragment; generating a key for each message fragment; encrypting each said message fragment to produce a respective encrypted message fragment; and transmitting each intelligent agent with said respective encrypted message fragment as a data payload. The method may further comprise receiving each intelligent agent with its respective encrypted message fragment as a data payload by a second intelligent agent environment at the receiver computer system; locating each of a set of agents; decrypting each encrypted respective message fragment to produce a respective cleartext message fragment; and collaborating by the set of agents to recombine cleartext message fragments to form a cleartext message.

The present invention relates to securely transmitting data, and more particularly to achieving improved protection against the breaching of security even when data is sent over a channel subject to interception.
The securing of data during transmission has been of interest throughout human history, and secure communication has been an essential part of commerce since time immemorial.
More recently, and especially since the widespread availability of computing power and technical means of data transmission, with sophisticated means of securing data transmitted over telecommunications channels and equally sophisticated technical means of decrypting messages, there has developed a rapidly-accelerating race between those who wish to secure messages and those who wish to "crack" them.
There is a constant search for new technical means of securing data during transmission by increasing the threshold of feasibility of decryption, and an equally constant search for means of rendering feasible decryptions that were thought to be infeasible. Similarly, the processing and transmission costs of sending information securely are of concern. The volume of data to be transmitted in the course of business transactions is increasing, and the cost of using public networks is constantly decreasing, while the cost of using private networks is ever more costly. It would be advantageous to be able to send more data, especially in bulk data applications, over less costly open channels, such as the Internet, but it is difficult to secure transmissions over such a medium to the standard normally required for commercial confidentiality purpose.
Modern encryption technology allows data to be very strongly encrypted, so that the degree of effort and time to crack any given encoding is nowadays very high or almost impossible to achieve. However, two weaknesses of the traditional "encrypt data, send data, receive and decrypt data" paradigm are that (1) the data is sent as a whole and (2) only one encryption/decryption key is normally used.
Published European patent application number EP 0 993 142 A1, for example, proposes a method for providing security for data wherein the bulk of transmitted data is encrypted and transmitted over an inherently less secure channel while selected segments of data are transmitted over a normally private channel, such as the telephone network. An eavesdropper on the less secure channel is thus prevented from reading all the data. Disclosed also is the notion of using one or more scrambling algorithms to scramble data according to a formula derived from the data itself.
Published PCT patent application number WO 00/18078 proposes a method whereby a message is split and transmitted over two channels in such a manner that the portion of the message to be sent over the less secure channel is encrypted, while the portion transmitted over the secure channel remains unencrypted.
Published US Patent Application number 2004/0083361 A1 discloses a method for transmitting data securely by adaptively transforming it and spreading the transformed data piece wise over plural transmission channels.
These known techniques provide some alleviation to the security problems described above. However, in the search for ever-improved secure methods, it is desirable to find a way of further increasing the security of a message by further reducing the computational feasibility of an unauthorized person's recovering the information content of the message, while limiting the cost of processing and transmission.

This patent is subject to a terminal disclaimer.

Collaborative agent encryption and decryption

International Business Machines Corporation


Systems and methods that facilitate securing data associated with a memory from security breaches are presented. A memory component includes nonvolatile memory, and a secure memory component (e.g., volatile memory) used to store information such as secret information related to secret processes or functions (e.g., cryptographic functions). A security component detects security-related events, such as security breaches or completion of security processes or functions, associated with the memory component and in response to a security-related event, the security component can transmit a reset signal to the secure memory component to facilitate efficiently erasing or resetting desired storage locations in the secure memory component in parallel and in a single clock cycle to facilitate data security. A random number generator component can facilitate generating random numbers after a reset based on a change in scrambler keys used by a scrambler component to descramble data read from the reset storage locations.

A wide variety of memory devices can be used to maintain and store data and instructions for various computers and similar systems. For instance, flash memory is a type of electronic memory media that can be rewritten and retain content without consumption of power. Unlike dynamic random access memory (DRAM) devices and static random memory (SRAM) devices in which a single byte can be erased, flash memory devices are typically erased in fixed multi-bit blocks or sectors. Flash memory technology can include NOR flash and/or NAND flash, for example. NOR flash evolved from electrically erasable read only memory (EEPROM) chip technology, in which, unlike flash, a single byte can be erased; and NAND flash evolved from DRAM technology. Flash memory devices can be less expensive and denser as compared to many other memory devices, meaning that flash memory devices can store more data per unit area.
Flash memory has become popular, at least in part, because it combines the advantages of the high density and low cost of EPROM with the electrical erasability of EEPROM. Flash memory is non-volatile; it can be rewritten and can hold its content without power. It can be used in many portable electronic products, such as cellular phones, computers, voice recorders, thumbnail drives, and the like, as well as in many larger electronic systems, such as automobiles, airplanes, industrial control systems, etc. The fact that flash memory can be rewritten as well as its retention of data without a power source, small size, and light weight have all contributed to make flash memory devices a useful and popular means for transporting and maintaining data.
Many electronic devices and systems employ cryptographic and/or other processes to facilitate securing data, such as sensitive and/or personal information of a user, that is associated with the electronic device. Typically, such electronic devices, which can use non-volatile memory (e.g., flash memory), can also employ other memory, such as volatile memory (e.g., random access memory (RAM), static RAM, etc.), which can be utilized to store key information (e.g., secret key) and/or results (e.g., intermediate results) associated with cryptographic computations related to encrypting and/or decrypting data associated with the electronic device. Hackers or other unauthorized entities may attempt to access the volatile memory in order to learn the key information and/or results stored therein and/or glean other information related thereto in order to discover the data (e.g., sensitive and/or person information of the user), keys, and/or processes (e.g., cryptographic processes) used to secure the data. It is desirable to efficiently and securely manage data associated with an electronic device to minimize the risk of unauthorized and undesired access to or disclosure of such information.
Cryptographic and other processes often can employ random numbers (e.g., true random numbers, pseudo-random numbers) to facilitate securing data associated with a memory and/or electronic device. A random number generator can be used to generate random numbers. Conventionally, random number generators can employ cryptographic computations and/or a physical process to generate random numbers. Such conventional techniques for generating random numbers can be inefficient, for example, with regard to the time necessary to generate the random numbers, the resources used to generate the random numbers, and/or power used to generate the random numbers. It is desirable to efficiently generate random numbers to facilitate securing data, while also reducing or minimizing time, resources, and power expended to generate the random numbers.

Instant hardware erase for content reset and pseudo-random number generation


A thermal system of a vehicle, including: a heat exchanger; a accumulator and a compressor; a cabin evaporator; a cabin condenser; and a battery; wherein the heat exchanger, accumulator, compressor, cabin evaporator, cabin condenser, and battery are connected to allow refrigerant heat and cool a passenger cabin and the battery in a single closed and connected circuit directly without any dedicated heat exchanger; and wherein the heating and cooling of the cabin and the battery are controlled by settings of a plurality of valves.

Hybrid vehicles including hybrid plug-in vehicles and electric vehicles are gaining popularity. These types of vehicles typically include one or more batteries. The batteries can be high voltage batteries that can be the main or secondary power source of the vehicle. For the batteries to operate normally, proper cooling and/or heating is needed. In addition, the temperature in the cabin of the vehicle also needs to be adjusted to provide a comfortable environment to the vehicle occupants. Accordingly, it is desirable to have a vehicle thermal system that can heat and cool both the passenger cabin and the battery pack of the vehicle with reduced complexity.


In a sheet feeding apparatus for separating individual sheets (1b, 1c) of different stiffness from stacks (1d) thereof, the stack is pressed under the urgency of a spring force against separating rollers (9) and the sheet supply container (1) has an inclined front wall surface (10) on its front wall (4) upon which the stacked sheets are supported. A pair of arms (12) carrying separating elements (3) on their lower ends are carried on the supply container side wall (1a) for substantially parallel movement therealong. The arms (12) are implemented as linearly-movable switch sides (13) which are reciprocally displaceable between a lowered position in which the separating element end surfaces (15) rest against the supply container front wall surface (10) or the front region (11) thereof, and an upper or raised position in spaced apart relation to and providing a well-defined clearance (16) relative to the topmost sheet in the stack (1d).

Devices for separating individual sheets to be printed from stacks of such sheets and capable of doing so with respect to sheets of considerably different thickness or relative flexibility or stiffness are known in the art. It is of particular interest that such devices have the ability to separate or individualize both relatively thin and highly flexible paper sheets, on the one hand, and relatively thicker or stiffer envelopes, on the other hand, from stacks thereof.
One heretofore-known apparatus for loading individual sheets into an office machine is disclosed in published European Patent Document No. EP-A2-01 06 801. This apparatus is intended to provide for ready separation of individual sheets and adaptation to different paper widths. More particularly, the separating elements are constructed as individualizing corners fastened to a bent portion of a swing plate which is mounted for rotation about an axis of rotation to a side wall of the sheet storage container. The storage container includes an inclined front wall surface which extends into a rounded portion, whereby the individual sheets rest on only the rounded portion of the inclined front wall surface when the separating elements are rotatably swung away for accommodating sheets or envelopes of increased or relatively greater thickness or stiffness.
This known structure is not, however, particularly advantageous when switching the rotatable swing plate between positions for accommodating one or the other of highly flexible paper sheets and relatively stiff envelopes. For one thing, the switched end positions of the rotatable swing plates are not well defined and, furthermore, significant additional clearance or free space about the swing plates must be provided to accommodate their rotational movement.

Sheet feeding apparatus for separating individual sheets from stacks of sheets of different relative stiffness


A double clutch transmission with two clutches connected to a drive shaft and to one of two transmission input shafts. Fixed gears are coupled to the input shafts and engage idler gears. Several coupling devices connect the idler gears to a countershaft which have an output gear that couple with gears of an output shaft such that forward and reverse gears can be shifted. Two dual gear planes each comprise two idler gears, each supported by a respective countershaft, and one fixed gear. In each dual gear plane, at least one idler gear is used for two gears. Two single gear planes each comprise an idler gear and a fixed gear such that at least one winding-path gear is shifted via a shifting device on the second countershaft, and at least one winding-path gear is shifted via a non-engaged coupling device, assigned to an output gear wheel on the first countershaft.

Known from the publication DE 103 05 241 A1 is a 6-speed or 7-speed dual clutch transmission. The dual clutch transmission comprises two clutches, each connected with their inputs to the drive shaft and the output to one of the two transmission input shafts. The two transmission input shafts are coaxially positioned towards each other. In addition, two countershafts are axially parallel to the transmission input shafts, their idler gear wheels mesh with the fixed gear wheels of the transmission input shafts. Furthermore, coupling devices that are axial movable are connected in a rotationally fixed manner to the countershaft to shift the respective gear wheels. Each selected ratio is transferred by the drive gear wheels to a differential transmission. To achieve the desired gear ratio steps in this known dual clutch transmission, a large number of wheel planes are required, so that a significant amount of installation space is required.
In addition, a spur gear variable-speed transmission is known from the publication DE 38 22 330 A1. The spur gear variable-speed transmission comprises a dual clutch that can be shifted under load one part of which is connected to a drive shaft and the other part is connected to a hollow drive shaft, rotatably supported on the drive shaft. For certain gear ratios, the drive shaft can be coupled with the hollow drive shaft through a shifting device.
Known from the publication DE 10 2004 001 961 A1 is a shift-under-load transmission with two clutches, each of which are assigned to a partial transmission. The transmission input shafts of the two partial transmissions are positioned coaxially with respect to each other and mesh, via fixed gear wheels, with idler gear wheels of the designated countershaft. The respective idler gear wheels of the countershafts can be connected in a rotationally fixed manner to the respective countershaft by means of designated shifting devices. The particular idler gear wheels of the countershaft can be connected in a rotationally fixed manner by means of the assigned shifting devices with the associated countershaft. A 7-gear transmission, among other things, is known from this publication in which an additional shift element is provided to connect the two transmissions input shafts to establish an additional transmission stage. The 7-gear transmission requires in this embodiment at least six wheel planes in the two partial transmissions, to achieve the transmission stages. This increases the construction length of the transmission in the axial direction, thereby significantly limiting its use in a motor vehicle.


A wireless provider system can manage services provided to a plurality of electronic wireless devices based upon geo-fenced spaces defined by respective sets of points in space. A wireless provider system can provide wireless access service to the plurality of electronic wireless devices. The wireless provider system can detect that a particular electronic wireless device of the plurality of electronic wireless devices is within a particular geo-fenced space. In response to this detecting, the system can identify at least one service associated with the particular geo-fenced space. The wireless provider system can, in response to the identifying, modify the wireless access service provided to the wireless device by attaching the at least one service to the particular electronic wireless device.

The present disclosure relates to geo-fenced spaces, and more specifically, to management of geo-fenced spaces by wireless service providers.
Mobile devices can use wireless services, such as services offered by various companies offering cellular-based services. As the capabilities of such services has improved, mobile devices, such as laptop computers, tablet computers, smartphones, digital book readers, and other devices, has continued to evolve and to expand in both functionality and breadth of utility. Much of this expansion has occurred at the application level in the form of individualized applications developed for a specific company or entity. A model in which different entities produce individualized applications can be a barrier to entry, especially when the applications require a high level of technical expertise to implement and manage

Wireless service provider management of geo-fenced spaces


Compositions and methods are disclosed for stimulating or inhibiting angiogenesis and/or cardiovascularization in mammals, including humans. Pharmaceutical compositions are based on polypeptides or antagonists thereto that have been identified for one or more of these uses. Disorders that can be diagnosed, prevented, or treated by the compositions herein include trauma such as wounds, various cancers, and disorders of the vessels including atherosclerosis and cardiac hypertrophy. In addition, the present invention is directed to novel polypeptides and to nucleic acid molecules encoding those polypeptides. Also provided herein are vectors and host cells comprising those nucleic acid sequences, chimeric polypeptide molecules comprising the polypeptides of the present invention fused to heterologous polypeptide sequences, antibodies which bind to the polypeptides of the present invention and to methods for producing the polypeptides of the present invention.

2.1. Angiogenesis
Angiogenesis, defined as the growth or sprouting of new blood vessels from existing vessels, is a complex process that primarily occurs during embryonic development. Under normal physiological conditions in adults, angiogenesis takes place only in very restricted situations such as hair growth and wounding healing (Auerbach, W. and Auerbach, R., 1994, Pharmacol Ther 63(3):265–3 11; Ribatti et al., 1991, Haematologica 76(4):3 11–20; Risau, 1997, Nature 386(6626):67 1–4). Unregulated angiogenesis has gradually been recognized to be responsible for a wide range of disorders, including, but not limited to cardiovascular disease, cancer, rheumatoid arthritis, psoriasis and diabetic retinopathy (Folkman, 1995, Nat Med 1(1):27–31; Isner, 1999, Circulation 99(13): 1653–5; Koch, 1998, Arthritis Rheum 41(6):951–62; Walsh, 1999, Rheumatology (Oxford) 38(2):103–12; Ware and Simons, 1997, Nat Med 3(2): 158–64).
2.2. Cardiac Disorders and Factors
Heart failure affects approximately five million Americans, and new cases of heart failure number about 400,000 each year. It is the single most frequent cause of hospitalization for people age 65 and older in the United States. Recent advances in the management of acute cardiac diseases, including acute myocardial infarction, are resulting in an expanding patient population that will eventually develop chronic heart failure. From 1979 to 1995, hospitalizations for congestive heart failure (CHF) rose from 377,000 to 872,000 (a 130 percent increase) and CHF deaths increased 116 percent.
CHF is a syndrome characterized by left ventricular dysfunction, reduced exercise tolerance, impaired quality of life, and markedly shortened life expectancy. The sine qua non of heart failure is an inability of the heart to pump blood at a rate sufficient to meet the metabolic needs of the body's tissues (in other words, there is insufficient cardiac output).
At least four major compensatory mechanisms are activated in the setting of heart failure to boost cardiac output, including peripheral vasoconstriction, increased heart rate, increased cardiac contractility, and increased plasma volume. These effects are mediated primarily by the sympathetic nervous system and the renin-angiotensin system. See, Eichhorn, American Journal of Medicine, 104: 163–169 (1998). Increased output from the sympathetic nervous system increases vascular tone, heart rate, and contractility. Angiotensin II elevates blood pressure by 1) directly stimulating vascular smooth muscle contraction, 2) promoting plasma volume expansion by stimulating aldosterone and antidiuretic hormone secretion, 3) stimulating sympathetic-mediated vascular tone, and 4) catalyzing the degradation of bradykinin, which has vasodilatory and natriuretic activity. See, review by Brown and Vaughan, Circulation, 97: 1411–1420 (1998). As noted below, angiotensin II may also have directly deleterious effects on the heart by promoting myocyte necrosis (impairing systolic function) and intracardiac fibrosis (impairing diastolic and in some cases systolic function). See, Weber, Circulation, 96: 4065–4082 (1998).
A consistent feature of congestive heart failure (CHF) is cardiac hypertrophy, an enlargement of the heart that is activated by both mechanical and hormonal stimuli and enables the heart to adapt to demands for increased cardiac output. Morgan and Baker, Circulation, 83: 13–25 (1991). This hypertrophic response is frequently associated with a variety of distinct pathological conditions such as hypertension, aortic stenosis, myocardial infarction, cardiomyopathy, valvular regurgitation, and intracardiac shunt, all of which result in chronic hemodynamic overload.
Hypertrophy is generally defined as an increase in size of an organ or structure independent of natural growth that does not involve tumor formation. Hypertrophy of the heart is due either to an increase in the mass of the individual cells (myocytes), or to an increase in the number of cells making up the tissue (hyperplasia), or both. While the enlargement of an embryonic heart is largely dependent on an increase in myocyte number (which continues until shortly after birth), post-natal cardiac myocytes lose their proliferative capacity. Further growth occurs through hypertrophy of the individual cells.
Adult myocyte hypertrophy is initially beneficial as a short term response to impaired cardiac function by permitting a decrease in the load on individual muscle fibers. With severe, long-standing overload, however, the hypertrophied cells begin to deteriorate and die. Katz, "Heart Failure", in: Katz A. M. ed., Physiology of the Heart (New York: Raven Press, 1992) pp. 638–668. Cardiac hypertrophy is a significant risk factor for both mortality and morbidity in the clinical course of heart failure. Katz, Trends Cardiovasc. Med., 5:37–44(1995). For further details of the causes and pathology of cardiac hypertrophy see, e.g., Heart Disease, A Textbook of Cardiovascular Medicine, Braunwald, E. ed. (W.B. Saunders Co., 1988), Chapter 14, "Pathophysiology of Heart Failure."
On a cellular level, the heart is composed of myocytes and surrounding support cells, generically called non-myocytes. While non-myocytes are primarily fibroblast/mesenchymal cells, they also include endothelial and smooth muscle cells. Indeed, although myocytes make up most of the adult myocardial mass, they represent only about 30% of the total cell numbers present in heart. In response to hormonal, physiological, hemodynamic, and pathological stimuli, adult ventricular muscle cells can adapt to increased workloads through the activation of a hypertrophic process. This response is characterized by an increase in myocyte cell size and contractile protein content of individual cardiac muscle cells, without concomitant cell division and activation of embryonic genes, including the gene for atrial natriuretic peptide (ANP). Chien et al., FASEB J., 5: 3037–3046 (1991); Chien et al., Annu. Rev. Physiol., 55: 77–95(1993). An increment in myocardial mass as a result of an increase in myocyte size that is associated with an accumulation of interstitial collagen within the extracellular matrix and around intramyocardial coronary arteries has been described in left ventricular hypertrophy secondary to pressure overload in humans. Caspari et al., Cardiovasc. Res., 11: 554–558 (1977); Schwarz et al., Am. J. Cardiol., 42: 895–903 (1978); Hess et al., Circulation, 63: 360–371 (1981); Pearlman et al., Lab. Invest., 46: 158–164 (1982).
It has also been suggested that paracrine factors produced by non-myocyte supporting cells may additionally be involved in the development of cardiac hypertrophy, and various non-myocyte derived hypertrophic factors, such as, leukocyte inhibitory factor (LIF) and endothelin, have been identified. Metcalf, Growth Factors, 7: 169–173 (1992); Kurzrock et al., Endocrine Reviews, 12: 208–217 (1991); Inoue et al., Proc. Natl. Acad. Sci. USA, 86: 2863–2867 (1989); Yanagisawa and Masaki, Trends Pharm. Sci., 10: 374–378 (1989); U.S. Pat. No. 5,573,762 (issued Nov. 12, 1996). Further exemplary factors that have been identified as potential mediators of cardiac hypertrophy include cardiotrophin-1 (CT-1) (Pennica et al., Proc. Nat. Acad. Sci. USA, 92: 1142–1146 (1995)), catecholamines, adrenocorticosteroids, angiotensin, and prostaglandins.
At present, the treatment of cardiac hypertrophy varies depending on the underlying cardiac disease. Catecholamines, adrenocorticosteroids, angiotensin, prostaglandins, LIF, endothelin (including endothelin-1, -2, and -3 and big endothelin), and CT-1 are among the factors identified as potential mediators of hypertrophy. For example, beta-adrenergic receptor blocking drugs (beta-blockers, e.g., propranolol, timolol, tertalolol, carteolol, nadolol, betaxolol, penbutolol, acetobutolol, atenolol, metoprolol, carvedilol, etc.) and verapamil have been used extensively in the treatment of hypertrophic cardiomyopathy. The beneficial effects of beta-blockers on symptoms (e.g., chest pain) and exercise tolerance are largely due to a decrease in the heart rate with a consequent prolongation of diastole and increased passive ventricular filling. Thompson et al., Br. Heart J., 44: 488–98 (1980); Harrison et al., Circulation, 29: 84–98 (1964). Verapamil has been described to improve ventricular filling and probably reducing myocardial ischemia. Bonow et al., Circulation, 72: 853–64 (1985).
Nifedipine and diltiazem have also been used occasionally in the treatment of hypertrophic cardiomyopathy. Lorell et al., Circulation, 65: 499–507 (1982); Betocchi et al., Am. J. Cardiol., 78: 451–457 (1996). However, because of its potent vasodilating properties, nifedipine may be harmful, especially in patients with outflow obstruction. Disopyramide has been used to relieve symptoms by virtue of its negative inotropic properties. Pollick, N. Engl. J. Med., 307: 997–999 (1982). In many patients, however, the initial benefits decrease with time. Wigle et al., Circulation, 92: 1680–1692 (1995). Antihypertensive drug therapy has been reported to have beneficial effects on cardiac hypertrophy associated with elevated blood pressure. Examples of drugs used in antihypertensive therapy, alone or in combination, are calcium antagonists, e.g., nitrendipine; adrenergic receptor blocking agents, e.g., those listed above; angiotensin converting enzyme (ACE) inhibitors such as quinapril, captopril, enalapril, ramipril, benazepril, fosinopril, and lisinopril; diuretics, e.g., chlorothiazide, hydrochlorothiazide, hydroflumethazide, methylchlothiazide, benzthiazide, dichlorphenamide, acetazolamide, and indapamide; and calcium channel blockers, e.g., diltiazem, nifedipine, verapamil, and nicardipine.
For example, treatment of hypertension with diltiazem and captopril showed a decrease in left ventricular muscle mass, but the Doppler indices of diastolic function did not normalize. Szlachcic et al., Am. J. Cardiol., 63: 198–201 (1989); Shahi et al., Lancet, 336: 458–461 (1990). These findings were interpreted to indicate that excessive amounts of interstitial collagen may remain after regression of left ventricular hypertrophy. Rossi et al., Am. Heart J., 124: 700–709 (1992). Rossi et al., supra, investigated the effect of captopril on the prevention and regression of myocardial cell hypertrophy and interstitial fibrosis in pressure overload cardiac hypertrophy, in experimental rats.
Agents that increase cardiac contractility directly (iontropic agents) were initially thought to benefit patients with heart failure because they improved cardiac output in the short term. However, all positive inotropic agents except digoxigenin have been found to result in increased long-term mortality, in spite of short-term improvements in cardiac performance. Massie, Curr. Op. in Cardiology, 12: 209–217 (1997); Reddy et al., Curr. Opin. Cardiol., 12: 233–241 (1997). Beta-adrenergic receptor blockers have recently been advocated for use in heart failure. Evidence from clinical trials suggests that improvements in cardiac function can be achieved without increased mortality, though documented improvements of patient survival have not yet been demonstrated. See also, U.S. Pat. Nos. 5,935,924, 5,624,806; 5,661,122; and 5,610,134 and WO 95/28173 regarding the use of cardiotropin-1 or antagonists thereof, or growth hormone and/or insulin-like growth factor-I in the treatment of CHF. Another treatment modality is heart transplantation, but this is limited by the availability of donor hearts.
Endothelin is a vasoconstricting peptide comprising 21 amino acids, isolated from swine arterial endothelial culture supernatant and structurally determined. Yanagisawa et al., Nature, 332: 411–415 (1988). Endothelin was later found to exhibit various actions, and endothelin antibodies as endothelin antagonists have proven effective in the treatment of myocardial infarction, renal failure, and other diseases. Since endothelin is present in live bodies and exhibits vasoconstricting action, it is expected to be an endogenous factor involved in the regulation of the circulatory system, and may be associated with hypertension, cardiovascular diseases such as myocardial infarction, and renal diseases such as acute renal failure. Endothelin antagonists are described, for example, in U.S. Pat. No. 5,773,414; JP Pat. Publ. 3130299/1991, EP 457,195; EP 460,679; and EP 552,489. A new endothelin B receptor for identifying endothelin receptor antagonists is described in U.S. Pat. No. 5,773,223.
Current therapy for heart failure is primarily directed to using angiotensin-converting enzyme (ACE) inhibitors, such as captopril, and diuretics. These drugs improve hemodynamic profile and exercise tolerance and reduce the incidence of morbidity and mortality in patients with CHF. Kramer et al., Circulation, 67(4): 807–816 (1983); Captopril Multicenter Research Group, J.A.C.C., 2(4): 755–763 (1983); The CONSENSUS Trial Study Group, N. Engl. J. Med., 316(23): 1429–1435 (1987); The SOLVD Investigators, N. Engl. J. Med., 325(5): 293–302 (1991). Further, they are useful in treating hypertension, left ventricular dysfunction, atherosclerotic vascular disease, and diabetic nephropathy. Brown and Vaughan, supra. However, despite proven efficacy, response to ACE inhibitors has been limited. For example, while prolonging survival in the setting of heart failure, ACE inhibitors appear to slow the progression towards end-stage heart failure, and substantial numbers of patients on ACE inhibitors have functional class III heart failure.
Moreover, improvement of functional capacity and exercise time is only small and mortality, although reduced, continues to be high. The CONSENSUS Trial Study Group, N. Engl. J. Med., 316(23): 1429–1453 (1987); The SOLVD Investigators, N. Engl. J. Med., 325(5): 293–302 (1991); Cohn et al., N. Engl. J. Med., 325(5): 303–310 (1991); The Captopril-Digoxin Multicenter Research Group, JAMA, 259(4): 539–544 (1988). Hence, ACE inhibitors consistently appear unable to relieve symptoms in more than 60% of heart failure patients and reduce mortality of heart failure only by approximately 15–20%. For further adverse effects, see Brown and Vaughan, supra.
An alternative to ACE inhibitors is represented by specific AT1 receptor antagonists. Clinical studies are planned to compare the efficacy of these two modalities in the treatment of cardiovascular and renal disease. However, animal model data suggests that the ACE/Ang II pathway, while clearly involved in cardiac hypertrophy, is not the only, or even the primary pathway active in this role. Mouse genetic "knockout" models have been made to test individual components of the pathway. In one such model, the primary cardiac receptor for Ang II, AT sub 1A, has been genetically deleted; these mice do not develop hypertrophy when Ang II is given experimentally (confirming the basic success of the model in eliminating hypertrophy secondary to Ang II). However, when the aorta is constricted in these animals (a model of hypertensive cardiac stress), the hearts still become hypertrophic. This suggests that alternative signaling pathways, not depending on this receptor (AT sub 1A), are activated in hypertension. ACE inhibitors would presumably not be able to inhibit these pathways. See, Harada et al., Circulation, 97: 1952–1959 (1998). See also, Homcy, Circulation, 97: 1890–1892 (1998) regarding the enigma associated with the process and mechanism of cardiac hypertrophy.
About 750,000 patients suffer from acute myocardial infarction (AMI) annually, and approximately one-fourth of all deaths in the United States are due to AMI. In recent years, thrombolytic agents, e.g., streptokinase, urokinase, and in particular tissue plasminogen activator (t-PA) have significantly increased the survival of patients who suffered myocardial infarction. When administered as a continuous intravenous infusion over 1.5 to 4 hours, t-PA produces coronary patency at 90 minutes in 69% to 90% of the treated patients. Topol et al., Am. J. Cardiol., 61: 723–728 (1988); Neuhaus et al., J. Am. Coll. Cardiol., 12: 581–587 (1988); Neuhaus et al., J. Am. Coll. Cardiol., 14: 1566–1569 (1989). The highest patency rates have been reported with high dose or accelerated dosing regimens. Topol, J. Am. Coll. Cardiol., 15: 922–924 (1990). t-PA may also be administered as a single bolus, although due to its relatively short half-life, it is better suited for infusion therapy. Tebbe et al., Am. J. Cardiol., 64: 448–453 (1989). At-PA variant, specifically designed to have longer half-life and very high fibrin specificity, TNK t-PA (a T103N, N117Q, KHRR(296–299)AAAA t-PA variant, Keyt et al., Proc. Natl. Acad. Sci. USA, 91: 3670–3674(1994)) is particularly suitable for bolus administration. However, despite all these advances, the long-term prognosis of patient survival depends greatly on the post-infarction monitoring and treatment of the patients, which should include monitoring and treatment of cardiac hypertrophy.
2.3. Growth Factors
Various naturally occurring polypeptides reportedly induce the proliferation of endothelial cells. Among those polypeptides are the basic and acidic fibroblast growth factors (FGF) (Burgess and Maciag, Annual Rev. Biochem., 58: 575 (1989)), platelet-derived endothelial cell growth factor (PD-ECGF) (Ishikawa et al., Nature, 338: 557 (1989)), and vascular endothelial growth factor (VEGF). Leung et al., Science, 246: 1306 (1989); Ferrara and Henzel, Biochem. Biophys. Res. Commun., 161: 851 (1989); Tischer et al., Biochem. Biophys. Res. Commun., 165: 1198 (1989); EP 471,754B granted Jul. 31, 1996.
Media conditioned by cells transfected with the human VEGF (hVEGF) cDNA promoted the proliferation of capillary endothelial cells, whereas control cells did not. Leung et al., Science, 246: 1306 (1989). Several additional cDNAs were identified in human cDNA libraries that encode 121-, 189-, and 206-amino acid isoforms of hVEGF (also collectively referred to as hVEGF-related proteins). The 121-amino acid protein differs from hVEGF by virtue of the deletion of the 44 amino acids between residues 116 and 159 in hVEGF. The 189-amino acid protein differs from hVEGF by virtue of the insertion of 24 amino acids at residue 116 in hVEGF, and apparently is identical to human vascular permeability factor (hVPF). The 206-amino acid protein differs from hVEGF by virtue of an insertion of 41 amino acids at residue 116 in hVEGF. Houck et al., Mol. Endocrin., 5: 1806 (1991); Ferrara et al., J. Cell. Biochem., 47: 211 (1991); Ferrara et al., Endocrine Reviews, 13: 18 (1992); Keck et al., Science, 246: 1309 (1989); Connolly et al., J. Biol. Chem., 264: 20017 (1989); EP 370,989 published May 30, 1990.
It is now well established that angiogenesis, which involves the formation of new blood vessels from preexisting endothelium, is implicated in the pathogenesis of a variety of disorders. These include solid tumors and metastasis, atherosclerosis, retrolental fibroplasia, hemangiomas, chronic inflammation, intraocular neovascular syndromes such as proliferative retinopathies, e.g., diabetic retinopathy, age-related macular degeneration (AMD), neovascular glaucoma, immune rejection of transplanted corneal tissue and other tissues, rheumatoid arthritis, and psoriasis. Folkman et al., J. Biol. Chem., 267: 10931–10934 (1992); Klagsbrun et al., Annu. Rev. Physiol., 53: 217–239 (1991); and Garner A., "Vascular diseases", In: Pathobiology of Ocular Disease. A Dynamic Approach, Garner A., Klintworth G K, eds., 2nd Edition (Marcel Dekker, NY, 1994), pp 1625–1710.
In the case of tumor growth, angiogenesis appears to be crucial for the transition from hyperplasia to neoplasia, and for providing nourishment for the growth and metastasis of the tumor. Folkman et al., Nature, 339: 58 (1989). The neovascularization allows the tumor cells to acquire a growth advantage and proliferative autonomy compared to the normal cells. A tumor usually begins as a single aberrant cell which can proliferate only to a size of a few cubic millimeters due to the distance from available capillary beds, and it can stay 'dormant' without further growth and dissemination for a long period of time. Some tumor cells then switch to the angiogenic phenotype to activate endothelial cells, which proliferate and mature into new capillary blood vessels. These newly formed blood vessels not only allow for continued growth of the primary tumor, but also for the dissemination and recolonization of metastatic tumor cells. Accordingly, a correlation has been observed between density of microvessels in tumor sections and patient survival in breast cancer as well as in several other tumors. Weidner et al., N. Engl. J. Med, 324: 1–6 (1991); Horak et al., Lancet, 340: 1120–1124 (1992); Macchiarini et al., Lancet, 340: 145–146 (1992). The precise mechanisms that control the angiogenic switch is not well understood, but it is believed that neovascularization of tumor mass results from the net balance of a multitude of angiogenesis stimulators and inhibitors (Folkman, 1995, Nat Med 1(1):27–31).
The search for positive regulators of angiogenesis has yielded many candidates, including aFGF, bFGF, TGF-α, TGF-β, HGF, TNF-α, angiogenin, IL-8, etc. Folkman et al., J.B.C., supra, and Klagsbrun et al., supra. The negative regulators so far identified include thrombospondin (Good et al., Proc. Natl. Acad. Sci. USA., 87: 6624–6628 (1990)), the 16-kilodalton N-terminal fragment of prolactin (Clapp et al., Endocrinology, 133: 1292–1299 (1993)), angiostatin (O'Reilly et al., Cell, 79: 315–328 (1994)), and endostatin. O'Reilly et al., Cell, 88: 277–285 (1996).
Work done over the last several years has established the key role of VEGF, not only in stimulating vascular endothelial cell proliferation, but also in inducing vascular permeability and angiogenesis. Ferrara et al., Endocr. Rev., 18: 4–25 (1997). The finding that the loss of even a single VEGF allele results in embryonic lethality points to an irreplaceable role played by this factor in the development and differentiation of the vascular system. Furthermore, VEGF has been shown to be a key mediator of neovascularization associated with tumors and intraocular disorders. Ferrara et al., Endocr. Rev., supra. The VEGF mRNA is overexpressed by the majority of human tumors examined. Berkman et al., J. Clin. Invest., 91: 153–159 (1993); Brown et al., Human Pathol., 26: 86–91 (1995); Brown et al., Cancer Res., 53: 4727–4735 (1993); Mattern et al., Brit. J. Cancer, 73: 931–934 (1996); Dvorak et al., Am. J. Pathol., 146: 1029–1039 (1995).
Also, the concentration levels of VEGF in eye fluids are highly correlated to the presence of active proliferation of blood vessels in patients with diabetic and other ischemia-related retinopathies. Aiello et al., N. Engl. J. Med., 331: 1480–1487 (1994). Furthermore, recent studies have demonstrated the localization of VEGF in choroidal neovascular membranes in patients affected by AMD. Lopez et al., Invest. Ophthalmol. Vis. Sci., 37: 855–868 (1996).
Anti-VEGF neutralizing antibodies suppress the growth of a variety of human tumor cell lines in nude mice (Kim et al., Nature, 362: 841–844 (1993); Warren et al., J. Clin. Invest., 95: 1789–1797 (1995); Borgström et al., Cancer Res., 56: 4032–4039 (1996); Melnyk et al., Cancer Res., 56: 921–924 (1996)) and also inhibit intraocular angiogenesis in models of ischemic retinal disorders. Adamis et al., Arch. Ophthalmol., 114: 66–71 (1996). Therefore, anti-VEGF monoclonal antibodies or other inhibitors of VEGF action are promising candidates for the treatment of solid tumors and various intraocular neovascular disorders. Such antibodies are described, for example, in EP 817,648 published Jan. 14, 1998 and in WO98/45331 and WO98/45332 both published Oct. 15, 1998.
There exist several other growth factors and mitogens, including transforming oncogenes, that are capable of rapidly inducing a complex set of genes to be expressed by certain cells. Lau and Nathans, Molecular Aspects of Cellular Regulation, 6: 165–202 (1991). These genes, which have been named immediate-early- or early-response genes, are transcriptionally activated within minutes after contact with a growth factor or mitogen, independent of de novo protein synthesis. A group of these intermediate-early genes encodes secreted, extracellular proteins that are needed for coordination of complex biological processes such as differentiation and proliferation, regeneration, and wound healing. Ryseck et al., Cell Growth Differ., 2: 235–233 (1991).
Highly-related proteins that belong to this group include cef 10 (Simmons et al., Proc. Natl. Acad. Sci. USA, 86: 1178–1182 (1989)), cyr 61, which is rapidly activated by serum- or platelet-derived growth factor (PDGF) (O'Brien et al., Mol. Cell Biol., 10: 3569–3577 (1990), human connective tissue growth factor (CTGF) (Bradham et al., J. Cell. Biol., 114: 1285–1294 (1991)), which is secreted by human vascular endothelial cells in high levels after activation with transforming growth factor beta (TGF-β), exhibits PDGF-like biological and immunological activities, and competes with PDGF for a particular cell surface receptor, fisp-12 (Ryseck et al., Cell Growth Differ., 2: 235–233 (1991)), human vascular IBP-like growth factor (VIGF) (WO 96/17931), and nov, normally arrested in adult kidney cells, which was found to be overexpressed in myeloblastosis-associated-virus-type-1-induced nephroblastomas. Joloit et al., Mol. Cell. Biol., 12: 10–21 (1992).
The expression of these immediate-early genes acts as "third messengers" in the cascade of events triggered by growth factors. It is also thought that they are needed to integrate and coordinate complex biological processes, such as differentiation and wound healing in which cell proliferation is a common event.
As additional mitogens, insulin-like growth factor binding proteins (IGFBPs) have been shown, in complex with insulin-like growth factor (IGF), to stimulate increased binding of IGF to fibroblast and smooth muscle cell surface receptors. Clemmons et al., J. Clin. Invest., 77: 1548 (1986). Inhibitory effects of IGFBP on various IGF actions in vitro include stimulation of glucose transport by adipocytes, sulfate incorporation by chondrocytes, and thymidine incorporation in fibroblast. Zapf et al., J. Clin. Invest., 63: 1077 (1979). In addition, inhibitory effects of IGFBPs on growth factor-mediated mitogen activity in normal cells have been shown.
2.4. Need for Further Treatments
In view of the role of vascular endothelial cell growth and angiogenesis in many diseases and disorders, it is desirable to have a means of reducing or inhibiting one or more of the biological effects causing these processes. It is also desirable to have a means of assaying for the presence of pathogenic polypeptides in normal and diseased conditions, and especially cancer. Further, in a specific aspect, as there is no generally applicable therapy for the treatment of cardiac hypertrophy, the identification of factors that can prevent or reduce cardiac myocyte hypertrophy is of primary importance in the development of new therapeutic strategies to inhibit pathophysiological cardiac growth. While there are several treatment modalities for various cardiovascular and oncologic disorders, there is still a need for additional therapeutic approaches.


The carriage of the present invention includes front and rear legs pivotally mounted to a frame. The front legs include first roller members mounted to carry the frame along a first directional path and steering roller members are mounted to the rear legs for carrying the frame along a plurality of directional paths to effect steering of the carriage. In addition to the first roller means, the front legs include front steering roller members which are also mounted to carry the frame along a plurality of directional paths transverse to the first directional path to effect steering at the front of the carriage. The front legs may be locked in a plurality of pivotal positions in which the front end of the carriage will rest either only on the first roller members or the front steering roller members. The location of the first roller members and the front steering roller members with respect to each other on the front legs is effective to cause only the first roller members to support the frame when the front legs are in one of the pivotal positions and to cause only the front steering roller members to support the frame when the front legs are in another of the pivotal positions for the front legs.

Such a carriage for a stretcher is known from U.S. Pat. No. 4,921,295. While the front legs at the front end or the frame have fixed, i.e. unpivotable castors (rollers), the rear legs are provided with pivotable steering rollers so that the carriage may be guided while being pushed. In order to bring a patient in shock into an appropriate position on the stretcher while moving the latter by means of the carriage, the front legs may be locked at the frame in at least two pivotal positions by means of disengagable locking device. In the one pivotal position, the front legs are pivoted down completely; this position is usually taken by the front legs when the carriage is moved. Additionally, the front legs may be locked in a second pivotal position wherein their angle to the frame is more acute than in the first position so that the front end of the carriage is lowered as necessary for positioning persons in shock.
Although the known carriage is provided with steering rollers, its maneuverability is limited. In narrow halls full of nooks and crannies, moving the carriage is difficult since a steering only by the rear steering rollers is not sufficient at narrow corners. Further, a lateral displacement of the carriage is impossible without a troublesome moving of the carriage back and forth and without maneuvering or lifting the same. When lifting the carriage, there is the danger that the patient is subjected to painful vibrations.
If the front rollers were replaced with pivotable castors, the carriage could hardly be controlled, if at all, when being moved on sloping surfaces. Further, the trailing necessary with guide rolls (i.e. the vertical pivot axis of the steering rollers lies ahead of the horizontal rotational axis of the steering rollers with respect to the direction of movement) would be disadvantageous when lowering the front end since, with the front legs inclined, the own weight of the carriage would exert a rotational moment on the steering rollers that would result in an undesired rotation of the steering roller about the pivot axis and keep the guide rollers in their forward movement position.
On the other hand, the castors at the front legs have to be designed unpivotable since it is necessary to be able to move the carriage exactly onto the loading platform of an ambulance. The solution of this problem, providing each front leg with a castor that may be locked in the forward position, is not practicable since the rotational moment, caused by the trailing of the steering rollers when the front end is lowered, would exert extremely great forces on the lock of the steering rollers, which would result in a rather high wear.

Stollenwerk Fabrik fur Sanitatsaustungen Hans Stollenwerk & Cie GmbH & Co.


The device comprises a monobloc subassembly (1) of cast stainless steel comprising a principal portion in the form of a disc (4) mounted on a collar (2) of the reservoir (3) and defining at least two channels (8, 9) for the passage of fluid, typically for filling, communication with the atmosphere, and withdrawal of liquid and gaseous phases reheated by atmospheric reheaters (23; 30) for the supply (31) of a controlled gaseous flow.

The present invention relates to reservoirs for cryogenic fluid and more particularly devices for closing and connecting to external conduits such reservoirs.
Known devices for closing and connecting reservoirs of cryogenic fluid are constituted by a mechanical-welded assembly of a closure plate and connection pieces machined and fixed, typically by welding, in openings machined in the closure plate. This technique is particularly cumbersome, because of the number of different pieces to be produced, stored and assembled, and the large amount of scrap resulting from problems of machining and welding constitute materials, typically austenitic stainless steels.
The present invention has for its object to provide a device of simplified structure permitting overcoming most of these problems and greatly reducing the cost of production and assembly.
To do this, the invention provides a device comprising a monobloc subassembly of cast stainless steel, typically produced by lost wax molding, defining at least two, typically at least three channels for the passage of fluid.
According to a more particular characteristic of the invention, the monobloc subassembly is made by molding from an austenitic stainless steel alloy comprising at least 16%, typically between 16 and 18.5% chromium, and at least 10%, typically between 10 and 10.13% nickel, and having, in the liquid phase, a ferrite content greater than 2%, preferably not exceeding 6%.
The present invention also has for its object a reservoir for cryogenic fluid, particularly liquid oxygen for household oxygen therapy, provided with such a device and typically provided with two atmospheric reheaters connected to outlet passages for the liquid and gas of the device.

Device for closing and connecting to external conduits a reservoir of cryogenic fluid, and reservoir provided with such a device

Abstract: Application particularly to cryogenic reservoirs for medical oxygen for oxygen therapy.

L""Air Liquide - Societe Anonyme a Directoire et Conseil de Surveillance pour l""Etude et l""Exploitation des Procedes Georges Claude


The present invention relates to an electron gun retaining a cathode and a plurality of electrodes with a pair of bead glasses and a method for manufacturing the same, wherein each of the bead glasses are provided with a convex portion at a position where a bead support for an electrode is buried on a side of the electrodes, each of bead bases of a beading apparatus on which the bead glasses are disposed is formed with a concave portion at a position corresponding to the convex portion of the bead glass, the bead glasses disposed on the bead bases are heated and softened, the bead supports for the cathode and the plurality of electrodes are buried and secured in the bead glasses, and the bead glasses each include convex portions on a side opposite to the electrodes. In accordance with the present invention, recesses and projections over the surfaces of the bead glasses on the electrode sides are reduced in size, thereby further increasing a supporting strength of the electrodes, preventing withstand voltage deterioration of the electron gun, and maximizing a yield in a manufacturing process of the electron gun.

The present invention relates to an electron gun and a method for manufacturing the same, and more particularly, to a beading method for burying a plurality of electrodes in bead glasses and an electron gun manufactured by this method.
In general, an electron gun is composed of a plurality of electrodes. An inline-type electron gun has such a particular construction that a plurality of electrodes are buried and securely held in bead glasses in order to precisely manufacture an assembly of the red, green and blue electrodes in order.
Referring to FIG. 4, a beading apparatus for burying the plurality of electrodes in the bead glasses is so arranged that bead base 3 each including a stopper 2 for supporting the bead glass 1 are respectively fixed on the top ends of two arms 4, which two arms 4 are in turn arranged to be brought into an opening/closing movement by an arm driving means not shown while each of them are being swirled or moved in parallel relation with each other, or while they swirls and moves in parallel simultaneously. The beading apparatus also includes a heating means (not shown) for heating and softening the bead glasses 1 which are supported by the bead bases 3.
The bead glasses 1 are mounted on the bead bases 3, prior to being heated and softened at a temperature in the vicinity of a melting point of approximately 1200.degree. C. The bead glasses 1 are then pressed against the ends of the plurality of electrodes 6 assembled on a beading jig 5 so as to bury these ends of the electrodes thereinto. Succeedingly, the bead glasses are brought back into a condition that they are at a normal temperature, thereby completing fixture of the plurality of electrodes in the bead glasses.
The same kind of apparatus as the above is disclosed in Japanese Utility Model Laid-open Publication No. 52-42052.
In a certain conventional bead glass 1, there is provided a rectangular parallelepiped glass 10 as shown in FIG. 10A or a glass 11 of FIG. 11A having a convex portion 11a on the side which is not in contact with a G.sub.4 -electrode as shown in FIG. 11A. In a case of the glass 10 of FIG. 10A, a bead base 3 having a flat surface where the glass is mounted, is employed as shown in FIG. 10B. On the contrary, in a case of the glass 11 of FIG. 11A, a bead base 3 provided with a concave portion 3a for receiving the convex portion 11a of the glass 11 is employed as shown in FIG. 11B. When the glasses 10 of FIG. 10A are applied to a beading process as described in FIG. 4 by means of the bead bases 3 shown in FIG. 10B, an electron gun illustrated in FIG. 10C can be obtained. Similarly, the glasses 11 of FIG. 11A are applied to the beading process by means of the bead bases 3 shown in FIG. 11B in order to manufacture an electron gun illustrated in FIG. 11C.
Additionally, in FIGS. 10C and 11C, a reference numeral 20 designates a cathode body structure, and reference numerals 21 to 26 designate G.sub.1 -electrode, G.sub.2 -electrode, G.sub.3 -electrode, G.sub.4 -electrode, G.sub.5 -electrode and G.sub.6 -electrode, respectively.

Electron gun and method for manufacturing the same


Embodiments relate to improving the biasing of active electronic components such as, for example, sense amplifiers. Embodiments include an adjustable bias signal generator that receives a reference signal as an input and generates a corresponding bias signal as an output. The adjustable bias signal generator may comprise a voltage driver and capacitor divider circuitry. In some embodiments, the capacitor divider circuitry is configurable by selecting specific capacitor dividers using a digital code. In other embodiments, the voltage driver is adjustable by applying different trim settings to tune the output of the voltage driver. The voltage driver may be temperature compensated by multiplexing different trim settings that correspond to different temperatures.

Active electronic components (e.g., sense amplifiers) may need to be biased to a particular voltage or current to properly operate. Biasing refers to providing particular operating conditions to a component or system so that the component or system operates at a desired operating point. Biasing may involve providing a specific voltage or current to a terminal of an electronic component.

Biasing electronic components using adjustable circuitry


A harvester attachment for stripping crop clusters from tall stalks such as corn includes an intake path into which the stalks are received. The stalks are pulled through a narrow gap disposed in the intake path to strip-off the crop clusters. A pair of rotary bladed members are arranged on opposite sides of the intake path beneath the narrow gap. Opposing blades on the rotating bladed members radially overlap as they rotate to engage and fracture the stalks. The tip speed of the blades on one of the bladed members is greater than the tip speed of the other bladed member to enable the stalks to be severed by the blades.

The invention concerns a process and apparatus for the harvesting of crop clusters of tall growing plants, for example corn and sunflowers, whereby the crop cluster or clusters grown on a stalk are separated from the stalk and collected, and thereafter the stalk is chopped up.
To harvest the crop clusters of tall growing plants, such as corn and sunflowers, the clusters have heretofore been separated by gripping the stalk with an intake roll and drawing the stalk through a gathering gap, the width of which is narrower than the diameter of the cluster, so that the cluster is torn off in the course of being drawn in. The crop cluster picked off in this manner is transported by a conveyor to a collector container of the harvester, by means of a chain, a belt or screw conveyor.
For the harvesting of crops of this type, existing agricultural harvesting machines are retro-fitted by the attachment of suitable gathering heads, which for example are driven directly or indirectly by a power take-off shaft. It is known to equip harvesting machines with attachments for crop clusters of this type, in particular for corn, wherein the harvesting machine is provided originally with a transverse drive shaft, that may be equipped with suitable driving means for harvesting attachments to be added. It is possible in this manner to render agricultural machines or harvesters capable of gathering corn in time for the corn harvest. These harvesting attachments grip the corn stalk very deep and draw it through an intake path, with the driven intake rolls being preceded by the intake gap.
German Patent No. 17 57 313 describes a harvesting attachment of this type, comprising intake rolls located on either side of the intake path and driven in opposing directions and a gathering gap through which the plant stalk is being drawn during harvesting. The crop clusters are unable to pass through the gathering gap, so they are torn from the stalk and taken over by a conveyor. The intake rolls are provided with projecting ribs which engage each other during rotation. In the intake area, the plant stalk gripped in this manner is fractured without actually being separated at this fracture location. This fracturing is restricted to the comminution of woody stalk material within the action range of the ribs, wherein continuous fibers (similar to flax breaking) remain preserved.
In order to safely grip the stalk of the plant and draw it through the gathering gap, various suggestions have been presented relative to the configuration of the intake rolls. According to German Patent No. 30 13 689, the rolls have a "star-shaped cross section", with the hollow grooves of one intake roll engaging the projecting ribs of the other intake roll.
According to U.S. Pat. Nos. 3,462,928 and No. 3,174,484, angled sections with pins are set on a shaft with a polygonal, preferably rectangular crosssection, which sections form a similar star-shape and cooperate with each other as in the above-described manner.
Another development is described in U.S. Pat. No. 2,604,750 wherein the ribs are in the form of cutting edges cooperating with an essentially cylindrical counter roll.
To improve the uptake of plants for example lying on the ground, it is proposed in German Patent No. 19 48 511 to rotate helix-equipped noses of the intake rolls at a different (higher) rpm, the intake parts gripping the stalk. For this purpose, the drive shaft of the intake part is in the form of a hollow shaft, through which extends the drive shaft for the nose of the intake roll.
In order to grip stalks of significantly different thicknesses, it is proposed in French Patent No. 1,268,615 to drive at least one of the intake rolls by means of a ball-and-socket joint, so that both of the intake rolls are located at a variable angle to each other and are spaced apart in the area of the nose of the intake roll at a distance corresponding to the stalk diameter.
In all cases, the intake rolls are rotating in opposite directions synchronously at the same rpm, to assure the cooperation of the rolls. A disadvantage here involves the fact that the stalk of the plant is broken but not chopped up or comminuted. To attain the necessary comminution of the stalks, a separate chopper is required, for example according to German Documents GM 67 51 770, GM 79 09 446 or AS 20 05 352.
German Patent 32 13 542 describes a harvester attachment, whereby the stalks are to be cut during their intake movement. For that purpose, a single intake roll is provided for each gathering gap, with the necessary support provided by a partial shrouding surrounding the intake roll. This partial shrouding is additionally equipped with blades pointing in the direction of the intake roll, with the ribs set onto the intake roll having recesses, so that the meshing of the blades in the ribs becomes possible. Aside from problems arising due to the asymmetry of the entry of the plant stalk into the partially shrouded area, squeezing between the ribs and the partial shroud occurs essentially for drawing in the stalk. The blades become effective to cut the stalk only if the stalk is drawn in a relatively pronounced oblique position relative to the intake roll. The squeezing itself only weakens the stalk without cutting the individual stalk sections, with the squeezing process requiring the application of considerable power by the intake roll.
It is, therefore, an object of the present invention to provide a process and apparatus whereby the above-discussed disadvantages are eliminated, and the separation of the individual sections of the plant stalks produced by the breaking or buckling of the stalk after the crop cluster is picked off, is necessarily obtained. A further object is to perform such a process by a modular attachment for harvesting machines, with the process being economical by reducing power requirements and the modular attachment having a simple and easily maintained configuration.

Process and apparatus for harvesting of crops from stalks and chopping the stalks


A punch assembly for a punch press is described which includes an external housing or sleeve having a punch slidably mounted therein with a spring such as a disc spring for yieldably biasing the punch toward one end of the sleeve and a removable stripper plate mounted on the sleeve in a position around the operating end of the punch. The punch is preferably keyed to the sleeve in more than one location and the stripper plate guides the punch by preventing rotation as well as lateral deflection. A retaining member such as a ring surrounds the stripper plate and can be manipulated manually, e.g. by rotating it, to enable the punch and stripper plate to be ejected by means of a spring.

There has existed the need for a high speed punching assembly to be used with the higher speed turret punch presses. High operating speeds and the increased use of standard tooling have created problems for prior punching assemblies, particularly when they are used to notch or nibble a workpiece. In a notching or nibbling operation in which a large area needs to be removed, a punch of a smaller size than the area to be removed can be used to nibble the material out in small bites. This creates a substantial lateral pressure on the punch since the punch is being used on only one or two sides. In the prior punching assemblies, the punch holder travels up and down in the press turret during this side loading, causing galling, seizing and bell-mouthing of the turret. It is therefore a general object to reduce this kind of wear and the expensive rework or replacement of the turret by limiting wear to the internal parts of the punching assembly.
In addition, the lubrication of previous punching assemblies has been a hit or miss proposition. This has contributed to premature damage and replacement of parts. Moreover, prior tools have had a tendency to overheat. It is therefore an object to provide a more effective means for lubricating and cooling the punching assembly, particularly the operating end of the punch.
The high speed steel from which the punch is made, while excellent in high temperature and abrasion resistance, is quite fragile and susceptible to chipping and spalling at its cutting edge. It is therefore an objective to support the punch at the working end in two dimensions, namely, by supporting it against both lateral and rotary movement.
Thus, in prior punching assemblies, wear was excessive and too much time was required to remove and replace the punch in from the punch assembly. The general objectives of the invention are to reduce wear, provide finished parts of better quality, i.e., flatter sheets, less burrs, longer punch life, quicker punch changing with more reliable and trouble free operation.
Punch devices have been previously proposed that include an external housing or sleeve within which the punch itself slides during operation. It is also known to provide a removable stripper plate surrounding the punch tip as shown for example in U.S. Pat. No. 4,248,111. These prior devices have certain shortcomings. Stripper plates are time-consuming to remove and replace. They also require a special tool for the manipulation of several retaining members used for securing the stripper in place. It is therefore one object to provide a way of more quickly and easily removing and replacing the stripper plate and punch including a self-locking provision that automatically secures the stripper plate in place. Moreover, prior punches of the type having a stripper could be used only as a push-type punch and were not suited for use with a push-pull ram, i.e., one in which the punch is pushed downwardly into engagement with the work and is also pulled back on the return stroke.
In view of these and other deficiencies of the prior art, the present invention has the following more specific objectives and advantages:
(a) The provision of an improved punching assembly having a means for more quickly and easily removing and replacing the punch and stripper plate;
(b) The provision of a feature for automatically locking the stripper plate in place on any one of several preset angular positions about the punch axis assembly;
(c) Provision for more effectively lubricating internal parts;
(d) Provision for the above-noted features in a push-pull style punch suited for use in a push-pull type punch press or press brake;
(e) A provision that enables the stripper plate to guide the punch both laterally and about its axis for improving alignment and stability especially when notching and nibbling;
(f) A provision for cooling the operating end of the punch by causing air to flow over it;
(g) A provision enabling the stripper plate to be removed with a single quick movement of the hand and to be ejected automatically with a pop-out action;
(h) The provision of a single retaining member for holding the stripper plate securely in place so that by shifting the retaining member the punch and stripper plate can be removed and replaced in about 30 seconds;
(i) Provision for enabling the punch and stripper plate to be removed for replacement while keeping the rest of the punch assembly intact;
(j) Provision for producing an audible signal when the punch has been released and can be removed; and
(k) Provision for making a length adjustment to compensate for punch length changes and the amount of punch penetration into the die.
These and other more detailed specific objects of the invention will be apparent in view of the following description setting forth but a few of the various ways in which the present invention can be accomplished in view of the accompanying description which illustrates the invention by way of example.


An optical transmitting unit transmits a pulsed laser beam oscillated by a pulsed laser beam oscillator to a focusing unit in a laser processing apparatus. A wavelength band expanding unit expands the wavelength band of the pulsed laser beam, and a pulse width expanding unit increases the pulse width of the expanded pulsed laser beam. A focusing lens focuses the expanded pulsed laser beam. An optical fiber transmits the focused pulsed laser beam through a collimating lens and a pulse width compressing unit compresses the pulse width of the collimated pulsed laser beam to restore the original pulse width for transmission.

1. Field of the Invention
The present invention relates to a laser processing apparatus for applying a pulsed laser beam to a workpiece to laser-process the workpiece.
2. Description of the Related Art
In a semiconductor device fabrication process, a plurality of crossing division lines called streets are formed on the front side of a substantially disk-shaped semiconductor wafer to thereby partition a plurality of bands where devices such as ICs and LSIs are respectively formed. The semiconductor wafer is cut along the streets to thereby divide the bands where the devices are formed from each other, thus obtaining individual semiconductor chips. Further, an optical device wafer is provided by forming photodetectors such as photodiodes or light emitting devices such as laser diodes on the front side of a sapphire substrate. The optical device wafer is also cut along the streets to obtain individual optical devices divided from each other, such as photodiodes and laser diodes, which are widely used in electric equipment.
As a method of dividing a wafer such as a semiconductor wafer and an optical device wafer along the streets, there has been proposed a method including the steps of applying a pulsed laser beam to the wafer along the streets to thereby form laser processed grooves on the wafer or modified layers inside the wafer along the streets and next breaking the wafer along the laser processed grooves or the modified layers. A laser processing apparatus for laser-processing a workpiece such as a wafer includes a chuck table for holding the workpiece and pulsed laser beam applying means for applying a pulsed laser beam to the workpiece held on the chuck table. The pulsed laser beam applying means includes a pulsed laser beam oscillator for oscillating a pulsed laser beam, focusing means for focusing the pulsed laser beam oscillated by the pulsed laser beam oscillator and applying this pulsed laser beam focused to the workpiece held on the chuck table, and optical transmitting means for transmitting the pulsed laser beam oscillated by the pulsed laser beam oscillator to the focusing means.
In general, the optical transmitting means for transmitting the pulsed laser beam oscillated by the pulsed laser beam oscillator to the focusing means is provided by an optical system composed of a lens and a mirror. However, the optical system composed of a lens and a mirror has a problem such that the flexibility of design is low, depending on a set position. To solve this problem, optical transmitting means using an optical fiber has been proposed (see Japanese Patent Laid-open No. Hei 5-277775, for example).


A method for increasing the permeability of a geologic formation by fracturing includes the step of pumping a solution of a borohydride into a well bore. The solution may also include a basic material such as sodium hydroxide. This step may be followed by pumping a second acidic solution into the well bore.

1. Field of Invention
The present invention relates to methods and fluid compositions for use in the extraction of hydrocarbons such as petroleum or natural gas from geological formations.
2. Description of the Related Art
"Fracking," short for "fracturing," is popular term for a collection of related techniques for increasing the permeability of geologic formations including hydrocarbons such as petroleum and natural gas, in order to increase the quantity of material that can be extracted from a given formation. Typically, these techniques involves injecting fracking fluid at high enough pressure into a well for the purpose of causing fractures or cracks in the formation emanating from the well and continuing deep into the formation. These cracks provide channels for the flow of trapped formation fluids such as, for example, gas, oil, water, etc., to the well bore. Fracking is applied to many formations improve the flow from the formation. Fracking is employed for the purpose of restoring or improving the porosity of the formation, and thus the permeability of the formation, by opening up the substrate or formation, so that the desired fluid or product can flow more easily to the well pipe.
Fracking is often accomplished by hydraulic methods, pneumatic methods, or by a combination of these methods. Hydraulic fracking is accomplished by pumping a liquid, usually water, along with "proppants," such as sand or ceramic materials, and often various chemical additives, into the well, forcing the substrate or formation to expand, and resulting in the creation of cracks or wormholes that facilitate the flow of fluids trapped in the formation to the well pipe. Often the injection material is pumped so fast that substantial hydraulic pressure is realized in the well, and the rate of dissipation is often measured as means of judging effectiveness.
The pneumatic method is similar. Enough pressure is generated by pumping gas into the well to force the surrounding formation to expand, which leads to crack formation and increased porosity, and, if proppants are used, to force the proppants into the cracks and pores to keep or prop them open after the pressure on the well is removed.
The gas employed in pneumatic fracking methods can be carbon dioxide, propane, nitrogen, or another gas. However, some gases, such as carbon dioxide and propane, liquefy at elevated pressures, limiting the pressure excursion on the well.
When nitrogen is used as the fracking gas, it must be pumped very quickly into the well, making it a difficult system to work.
There is a continuing need for improved fracking methods that can be employed to extract mineral resources from geological formations.

Method for enhancing the permeability of a geological formation


A system for sharing sounds on a phone call, using a smartphone having a touchscreen display, having a sound library containing a plurality of sounds, and having an app for facilitating the sound sharing functionality, and for initiating a phone call. The app includes a pad controller view which displays a plurality of pads that may each be associated with one of the sounds in the library and will play that sound upon request. The app includes means for associating the sounds with the pads, for editing the sounds associated with the pads, and for adjusting the relative volume of sounds associated with the pads with a mix that may be provided as outgoing audio on the phone call.

Smartphones have gone well beyond their expected use of allowing a person to conveniently make phone calls wherever they are. In addition to the endless variation of apps available that occupy them between phone calls, people use their smartphones to share photos, videos, textual comments and messages. Such sharing can often occur during a voice call, but is typically one-way, and not in a collaborative manner.
It is well known that the way that music spreads in popularity is by people sharing it with others. In decades past, people would loan their favorite LP, single, 8-track, cassette tape, or CD to a friend as a way to share their enjoyment of a new favorite song or group. As music distribution moved away from physical distribution and toward electronic distribution, "sharing" sites exploded in popularity and became the way that people shared what they like best. Presently, however, only the direct online purchase of music is available, and with the DRM (digital rights management) data encoded in music files, it has become difficult, if not impossible to even just showcase our favorite music to others.
Also, some of the best new music comes about through collaboration. While lone singer/songwriters do account for some music, the majority of new music is created by more than one person. Those people might not be in the same location, making collaboration difficult. While, as noted previously, it is very easy for people to connect with photos, videos, text, and voice using our smartphones, there are no effective solutions for connecting and collaborating around the creation of music.
While these units may be suitable for the particular purpose employed, or for general use, they would not be as suitable for the purposes of the present disclosure as disclosed hereafter.
In the present disclosure, where a document, act or item of knowledge is referred to or discussed, this reference or discussion is not an admission that the document, act or item of knowledge or any combination thereof was at the priority date, publicly available, known to the public, part of common general knowledge or otherwise constitutes prior art under the applicable statutory provisions; or is known to be relevant to an attempt to solve any problem with which the present disclosure is concerned.
While certain aspects of conventional technologies have been discussed to facilitate the present disclosure, no technical aspects are disclaimed and it is contemplated that the claims may encompass one or more of the conventional technical aspects discussed herein.

System for sharing sounds from a smartphone during a voice call


The machine comprises first and second screw rotors (1, 2) supported by bearings (47) in a stator casing (3) which is provided with a suction inlet and a delivery outlet, the first rotor is driven by a motor (10) and the second rotor is driven by means of synchronizing gearing (11-12) situated in a first chamber (14) of the casing and located between the motor (10) and one of the ends of the rotors, the gearing (11-12) running in a lubricating fluid (15), the machine is characterized in that the cavity (30) of the casing containing the rotors (1-2) is separated from the first chamber (14) by a first wall (16) having the shafts (8, 13) of the rotors passing therethrough via seals (17-18), in that the shafts of the rotors at the opposite ends of the rotors to the ends having the gearing pass through a second wall (20) via seals (24-25), and in that the casing (3 ) includes, beyond the second wall (20), a second chamber (31) connected to the first chamber (14) by a main pipe (29) provided with pumping means (49), the rotors and the stator-casing including fluid circulation channels (32 to 34) terminating firstly in the second chamber (31) and secondly in the first chamber (14) and/or in that portion of the pipe (29) lying between the first chamber (14) and the pumping means, with a heat exchanger (41) being disposed on the path of the pipe (29).

These machines are driven by a motor and they have a high flow rate, greater than 50 m.sup.3 /h, and they rotate at speeds higher than 10,000 revolutions per minute (rpm). At atmospheric pressure they are capable of maintaining suction down to a pressure of 10.sup.-2 mbar. At a suction pressure in the range 200 mbar to 300 mbar, they absorb large amounts of power which is dissipated entirely as heat. Since the rotor and the stator are very different in thermal mass and in thermal dissipation, it is necessary to place considerable clearance between the rotors and the stator in order to avoid seizing. This gives rise to a poor quality flowrate/pressure characteristic.
An object of the present invention is to improve the flow rate-pressure characteristic by taking measures that make it possible to reduce the clearance between the rotors and the stator.

Rotary screw machine with multiple chambers in casing for lubrication-coding fluid


A boost converter capable of reducing a common-mode current that flows to the outside of a casing. In the converter, a boost circuit includes first and second inductors and at least one switching element electrically connected therebetween. A controller turns on and off the at least one switching element to boost an input voltage of the boost circuit. A first floating capacitor is formed between a first electrical path, which is at the same potential as a junction between the at least one switching element and the first inductor, and a mounting member coupled to a reference potential member with an insulator therebetween. A second floating capacitor is formed between a second electrical path, which is at the same potential as a junction between the at least one switching element and the second inductor, and the mounting member.

1. Technical Field
The present invention relates to a boost converter for boosting an input voltage thereof.
2. Related Art
An existing chopper boost circuit, as disclosed in U.S. Pat. No. 7,804,281, includes a switching element (N channel MOSFET), a pair of inductors, and a diode, to boost an input voltage to output a boosted voltage. More specifically, the pair of inductors are electrically connected to the respective terminals of the switching element, and an anode of the diode is electrically connected to the junction between one of the inductors and the switching element.
In such a chopper boost circuit, floating capacitors may be formed between the boost circuit and a casing (frame ground). More specifically, for example, floating capacitors may be formed between the drain of the switching element and the casing and between the cathode of the diode and the casing. In the presence of such floating capacitors, a variation in voltage applied across the switching element may cause a common-mode current to flow to the casing. More specifically, the floating capacitors between the boost circuit and the casing are charged and discharged through the variation in applied voltage across the switching element, which will cause the common-mode current to flow to the casing. The common-mode current flowing to the outside via the casing may, for example, lead to interference with some other electronic devices.
To address such deficiencies, the boost circuit disclosed in U.S. Pat. No. 7,804,281 requires a predefined balanced condition between the inductance values of the pair of inductors and the capacitance values of the pair of floating capacitors between the boost circuit and the casing. More specifically, for example, it is required that the inductance values of the pair of inductors coincide with each other and the capacitance values of the pair of floating capacitors coincide with each other. This may lead to reduction of common-mode current.
With the technique disclosed in U.S. Pat. No. 7,804,281, the common-mode current can be reduced. In some situations, however, where the boost circuits are designed for mass production, it may be difficult to satisfy the aforementioned balanced conditions between the inductance values of the pair of inductors and the capacitance values of the pair of floating capacitors. When the balanced conditions are not satisfied, sufficient reduction of the common-mode current may not be expected.
In consideration of the foregoing, it would therefore be desirable to have a boost converter capable of substantially reducing a common-mode current flowing to the outside of a boost circuit.